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Effects of breed, parity and post-mating nutrition on reproductive wastage and pregnancy outcomes of Egyptian sheep
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Effects of breed, parity and post-mating nutrition on reproductive wastage and pregnancy outcomes of Egyptian sheep I.I. Abdel-Mageed ∗ , M.H. Abd El-Gawad Animal Production Department, Faculty of Agriculture, Cairo University, 12613 Giza, Egypt
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Article history: Received 28 December 2014 Received in revised form 8 May 2015 Accepted 12 June 2015 Available online xxx Keywords: Sheep Rahmani and Barki breeds Parity Post-mating nutrition Reproductive wastage Pregnancy outcomes
a b s t r a c t The aim of this work was to investigate the effects of breed, parity and post-mating nutrition on reproductive wastage and pregnancy outcomes in subtropical sheep. The experimental design was completely randomized and different groups of ewes were arranged factorially (2 × 2 × 3) according to the breed (Rahmani or Barki), parity of the ewes (nulliparous or parous) and post-mating nutritional regimen through the first 45 days of pregnancy (70%, 100% and 130% of maintenance requirements). Barki ewes had higher ability to store back fat through the last third of pregnancy compared to Rahmani ewes. The parous ewes had higher body weight gain and higher body condition score through pregnancy, while they lost lower body weight and body condition score through suckling. The under-nourished ewes had lower body weight, body condition score, back fat and back muscle throughout the whole reproductive cycle. Higher reproductive wastage at weaning was observed in the nulliparous ewes (70%) compared to the parous ones (42%). The under- and the over-nourished groups had a double-fold reproductive wastage through different times of reproductive cycle compared to those fed the maintenance requirements. The parous and the moderately-fed sheep had higher proportion of lambs born, kilograms born, lambs weaned, kilograms weaned and ewes weaned to ewes conceived. Therefore, to maximize lamb crop at weaning, it is important to control the feeding allowance of ewes in early pregnancy to be similar to the maintenance requirements. © 2015 Elsevier B.V. All rights reserved.
1. Introduction Production of healthy-weaned lambs is the main target of sheep breeders. It can be achieved by reducing the reproductive wastage of ewes throughout the different stages of the reproductive cycle. Number of weaned lambs and weaned weight depend on the reproductive wastage in ewes. The highest rate of embryo loss occurs during the time of maternal recognition of pregnancy (Squires, 2003). Dixon et al. (2007) concluded that, the complete pregnancy failure before day 25 accounted for 28%, and approximately 3–4% of the potential offspring were lost for each 20-d period of pregnancy beyond day 25. Reproductive wastage in the ewe from ovulation to parturition may range between 30% (Bolet, 1986) and 43.3% (Dixon et al., 2007). Kleemann and Walker (2005) observed reproductive wastage, at weaning, to be 42.4% of ova shed. Ewe nutrition during early pregnancy has a very important role throughout its reproductive cycle. It influences placental and fetal growth (Igwebuike,
∗ Corresponding author. Tel.: +20 1008715012 (mobile); fax: +20 2 37745574. E-mail addresses: [email protected], [email protected] (I.I. Abdel-Mageed).
2010), conditions offspring adult health (Debus et al., 2012) and influence the weaning weight and the lactational performance of ewe offspring (Paten et al., 2013). This paper investigated the effects of breed, parity and post-mating nutrition on reproductive wastage and pregnancy outcomes of two Egyptian sheep breeds, Rahmani and Barki. 2. Material and methods The present study was carried out at the experimental farm of the Animal Production Department, Faculty of Agriculture, Cairo University, Giza, Egypt, to investigate the effects of breed, parity and post-mating nutrition on reproductive wastage and pregnancy outcomes in two Egyptian sheep breeds (Rahmani [R] and Barki [B], n = 64, Table 1). The latitude of this location is 30◦ N and the longitude is 31◦ E. The initial body weight, age, body condition score, back fat thickness and back muscle depth of ewes, of the two breeds, are presented in Table 2. The breeding season extended from mid-May to mid-July. Immediately after mating, ewes within breed (Rahmani and Barki) and parity (nulliparous and parous), were allocated into three groups according to nutritional regimen that they consume daily;
http://dx.doi.org/10.1016/j.smallrumres.2015.06.009 0921-4488/© 2015 Elsevier B.V. All rights reserved.
Please cite this article in press as: Abdel-Mageed, I.I., El-Gawad, M.H.A., Effects of breed, parity and post-mating nutrition on reproductive wastage and pregnancy outcomes of Egyptian sheep. Small Ruminant Res. (2015), http://dx.doi.org/10.1016/j.smallrumres.2015.06.009
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Table 1 Numbers of ewes per treatment used to study the effects of breed, parity and nutritional level during the first 45 days post-mating. Ewes breeds
Total
Rahmani
Barki
10 18
10 26
20 44
Post-mating nutritional level 8 70% of MR 11 100% of MR 9 130% of MR
12 12 12
20 23 21
Parity Nulliparous Parous
MR = maintenance requirements.
(1) 70% of maintenance requirements (MR), (2) 100% of MR and (3) 130% of MR. The nutritional regimen continued through the first 45 days after mating. While through the rest of the pregnancy and suckling periods, the three groups had the same regimen according to their feeding allowances that varied according to the stage of reproductive cycle (NRC, 1985). Ewes were maintained in semishaded pens, with drinking water freely available. Clover, clover hay, a concentrate mixture (13% CP and 0.65 kg TDN) and wheat straw were used in the diet formulation according to season. The concentrate mixture consisted of 55% yellow corn, 20% wheat bran, 10% cottonseed cake, 10% soybean meal, 2% limestone, 1.5% common salt, 1% minerals mixture, 0.4% sodium bicarbonate and 0.1% AD3E vitamins. Feeds chemical composition and nutritive value used for the experimental rations are presented in Table 3. Animals were synchronized for oestrus using two intramuscular injections of Estrumate (PGF2␣, each of 1 ml, 250 g Cloprostenol, Coopers Co., England) at an 11-day interval. Simultaneously with the 2nd treatment of Estrumate, fertile rams of the same breed were introduced in a ratio of 1:8. The traits measured on ewes at Days 45, 90, 140 of pregnancy, mid-suckling and weaning were body weight (BW), body condition score (BCS), back fat thickness (BF), back muscle depth (BM) and reproductive wastage (RW). The measurements of BW, BCS, BF and BM were calculated as the differences between the corresponding values at mating and at the different stages of the reproductive cycle. Numbers of lambs born (LB/EC), kilograms born (KgB/EC), lambs weaned (LW/EC), kilograms weaned (KgW/EC) and ewes weaned (EW/EC) per ewes conceived were also calculated. Reproductive wastage was measured as the difference between ovulation rate (OR) and number of embryos, fetuses, lambs born or lambs weaned, in relation to OR. The OR was measured by counting the number of corpora lutea at day 7 after mating. The measurements of BF, BM and OR were measured by ultrasonography, using a 6–8 MHz real-time, B-mode linear array ultrasound scanner (Model: Scanner 100 LC, Pie Medical Company, Masstricht, Netherlands) provided with transrectal transducer. The experimental design was completely randomized and the groups of ewes arranged factorially (2 × 2 × 3), according to the breed (Rahmani or Barki), parity of ewes (nulliparous or parous) and post-mating nutritional regimen (70% of MR, N1, 100% of MR, N2, or 130% of MR, N3) being the main effects. The interactions were
Table 3 Chemical composition and nutritive value of the experimental rations. Item
CFM
BH
WS
DM
89.2
91.68
90
Chemical composition, DM (%) 96.16 OM 14.11 CP 4.20 EE CF 8.51 69.34 NFE 3.84 Ash
83.99 10.31 2.54 31.43 39.71 16.01
85.21 3.79 1.79 44.87 34.76 14.79
Fiber fraction (%) NDF ADF ADL Hemicellulose Cellulose
30.73 8.84 2.31 21.89 6.53
45.90 31.05 7.44 14.85 23.61
81.97 53.68 6.89 28.29 46.79
Nutritive Value (%) DCP TDN
13 65
9 48
1 44
CFM: The concentrate feed mixture, BH: berseem hay, WS: Wheat straw. Hemicellulose = NDF-ADF, Cellulose = ADF-ADL.
considered and no significant differences were observed. Data of the measured traits were analyzed using the SAS GLM procedure. The Least Squares Means (LSM) were obtained for the BW, BCS, BF, BM, KgB/EC and KgW/EC traits. While the RW, LB/EC, LW/EC and EW/EC traits were analyzed using the chi-square CATMOD procedure. The Tukey’s Studentized Range (HSD) Test was used to detect differences among means. The significance level was set at P < 0.05 (SAS, 2004). 3. Results The effects of ewes’ breed, parity and post-mating nutrition on body weight (BW), body condition score (BCS), back fat thickness (BF) and back muscle depth (BM) are presented in Tables 4–7. No significant differences were observed between Rahmani and Barki ewes for BW, BCS and BM at the different stages of the reproductive cycle. Barki had higher ability to store backfat than Rahmani ewes through the last third of pregnancy. The effect of parity was significant in both BW and BCS. Parous ewes gained higher weights and more BCS units through pregnancy. They also lost less weights and BCS units throughout the suckling period. The effect of post-mating nutrition on ewes body measurements was significant through the first two thirds of pregnancy. The under-nourished group had lower (P < 0.05) BW, BCS, BF and BM at Day 45 post conception. This significant effect extended to Day 90 but it disappeared at lambing. The effect of both BW and BCS was significant again at mid-suckling, where the under-nourished group had lower values than the other two groups. The effects of ewes’ breed, parity and post-mating nutrition on reproductive wastage (RW) are presented in Table 8. Breed of sheep had no significant effect on RW. Higher RW, at weaning, was observed in the nulliparous ewes compared to the parous ones (70% vs. 42%, respectively). The under- and the over-nourished groups
Table 2 Means and SD of body weight (BW), age, body condition score (BCS), back fat thickness (BF) and back muscle depth (BM) of two breeds of Egyptian ewes at the beginning of the study. N
Rahmani Barki
28 36
BW (kg)
Age (years)
BCS (unit)
BF (mm)
BM (cm)
Mean
SD
Mean
SD
Mean
SD
Mean
SD
Mean
SD
37.64 34.99
4.87 4.72
3.11 3.31
0.98 1.02
2.41 2.73
0.47 0.41
1.41 1.72
0.63 0.69
1.76 1.98
0.32 0.42
Please cite this article in press as: Abdel-Mageed, I.I., El-Gawad, M.H.A., Effects of breed, parity and post-mating nutrition on reproductive wastage and pregnancy outcomes of Egyptian sheep. Small Ruminant Res. (2015), http://dx.doi.org/10.1016/j.smallrumres.2015.06.009
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Table 4 Effects of ewes’ breed (Rahmani, R and Barki, B), parity (nulliparous, P1 and parous, P2) and post-mating nutrition (70%, N1, 100%, N2 and 130%, N3 of the maintenance requirements) on body weight difference (LSM ± SE, kg) at different times of the reproductive. Day 45 Breed R B Parity P1 P2 Post-mating nutrition N1 N2 N3
Day 90
Day 140
Mid-suckling
Weaning
0.11 ± 0.25 −0.08 ± 0.24
2.05 ± 0.45 1.49 ± 0.43
5.11 ± 0.67 6.07 ± 0.65
0.09 ± 0.75 −0.25 ± 0.72
−1.12 ± 0.74 −0.35 ± 0.71
−0.97 ± 0.28b 0.44 ± 0.18a
0.15 ± 0.49b 2.45 ± 0.33a
3.12 ± 0.73b 6.08 ± 0.49a
−2.00 ± 0.82b 0.76 ± 0.54a
−2.12 ± 0.80b −0.03 ± 0.53a
−2.20 ± 0.25c 0.17 ± 0.26b 1.90 ± 0.26a
−0.02 ± 0.45c 1.90 ± 0.46b 3.20 ± 0.47a
4.77 ± 0.67 5.98 ± 0.69 6.07 ± 0.70
−1.40 ± 0.75b 0.78 ± 0.77a 0.17 ± 0.78a
−1.52 ± 0.74 −0.17 ± 0.76 −0.45 ± 0.77
Columns, within the same treatment, followed by different superscripts, differ significantly from each other (P < 0.05).
Table 5 Effects of ewes’ breed (Rahmani, R and Barki, B), parity (nulliparous, P1 and parous, P2) and post-mating nutrition (70%, N1, 100%, N2 and 130%, N3 of the maintenance requirements) on body condition score difference (LSM ± SE, unit) at different times of the reproductive cycle. Day 45 Breed R B Parity P1 P2 Post-mating nutrition N1 N2 N3
Day 90
Day 140
Mid-suckling
Weaning
0.06 ± 0.05 0.05 ± 0.05
0.24 ± 0.06 0.22 ± 0.05
0.47 ± 0.07 0.43 ± 0.07
0.18 ± 0.07 0.11 ± 0.07
−0.04 ± 0.08 −0.01 ± 0.08
0.00 ± 0.06 0.08 ± 0.04
0.15 ± 0.06 0.26 ± 0.04
0.26 ± 0.08b 0.53 ± 0.05a
0.02 ± 0.08b 0.20 ± 0.05a
−1.19 ± 0.09b 0.05 ± 0.06a
−0.26 ± 0.05c −0.04 ± 0.05b 0.44 ± 0.05a
0.04 ± 0.06c 0.22 ± 0.06b 0.41 ± 0.06a
0.36 ± 0.07 0.50 ± 0.08 0.47 ± 0.08
0.02 ± 0.08b 0.26 ± 0.08a 0.13 ± 0.08ab
−0.09 ± 0.08 0.08 ± 0.08 −0.07 ± 0.09
Columns, within the same treatment, followed by different superscripts, differ significantly from each other (P < 0.05).
Table 6 Effects of ewes’ breed (Rahmani, R and Barki, B), parity (nulliparous, P1 and parous, P2) and post-mating nutrition (70%, N1, 100%, N2 and 130%, N3 of the maintenance requirements) on back fat thickness difference (LSM ± SE, mm) at different times of the reproductive cycle. Day 45 Breed R B Parity P1 P2 Post-mating nutrition N1 N2 N3
Day 90
Day 140
Mid-suckling
Weaning
0.00 ± 0.05 0.02 ± 0.05
0.03 ± 0.08 0.08 ± 0.08
0.71 ± 0.17b 1.16 ± 0.16a
0.21 ± 0.35 0.21 ± 0.34
−0.16 ± 0.10 −0.29 ± 0.10
−0.03 ± 0.06 0.03 ± 0.04
0.02 ± 0.09 0.08 ± 0.06
1.05 ± 0.19 0.93 ± 0.12
0.16 ± 0.38 0.23 ± 0.25
−0.14 ± 0.11 −0.28 ± 0.07
−0.17 ± 0.05c 0.00 ± 0.06b 0.21 ± 0.06a
−0.15 ± 0.08b 0.13 ± 0.09a 0.19 ± 0.09a
1.14 ± 0.17 0.88 ± 0.17 0.89 ± 0.18
0.41 ± 0.35 0.04 ± 0.36 0.20 ± 0.36
−0.25 ± 0.10 −0.14 ± 0.10 −0.32 ± 0.11
Columns, within the same treatment, followed by different superscripts, differ significantly from each other (P < 0.05).
Table 7 Effects of ewes’ breed (Rahmani, R and Barki, B), parity (nulliparous, P1 and parous, P2) and post-mating nutrition (70%, N1, 100%, N2 and 130%, N3 of the maintenance requirements) on back muscle depth difference (LSM ± SE, cm) at different times of the reproductive cycle. Day 45 Breed R B Parity P1 P2 Post-mating nutrition N1 N2 N3
Day 90
Day 140
Mid-suckling
Weaning
0.03 ± 0.04 −0.01 ± 0.04
0.14 ± 0.06 0.06 ± 0.06
0.29 ± 0.09 0.22 ± 0.09
−0.12 ± 0.07 −0.25 ± 0.07
−0.16 ± 0.07 −0.25 ± 0.07
0.00 ± 0.04 0.00 ± 0.03
0.11 ± 0.06 0.08 ± 0.04
0.27 ± 0.10 0.24 ± 0.06
−0.14 ± 0.08 −0.24 ± 0.05
−0.22 ± 0.08 −0.20 ± 0.05
−0.18 ± 0.04c 0.00 ± 0.04b 0.18 ± 0.04a
−0.05 ± 0.06c 0.09 ± 0.06b 0.24 ± 0.06a
0.16 ± 0.09 0.23 ± 0.09 0.35 ± 0.09
−0.26 ± 0.07 −0.13 ± 0.07 −0.23 ± 0.07
−0.25 ± 0.07 −0.12 ± 0.08 −0.27 ± 0.06
Columns, within the same treatment, followed by different superscripts, differ significantly from each other (P < 0.05).
had a double-fold RW through the different stages of reproductive cycle compared to those fed the maintenance requirements. The effects of ewes’ breed, parity and post-mating nutritional level on LB/EC, LW/EC, EW/EC, KgB/EC and KgW/EC are presented
in Figs. 1–5. Both parity and post-mating nutrition significantly affected these traits. The parous ewes had higher values than the nulliparous ones. Also the moderately-fed group had higher values than the under- or the over-fed groups.
Please cite this article in press as: Abdel-Mageed, I.I., El-Gawad, M.H.A., Effects of breed, parity and post-mating nutrition on reproductive wastage and pregnancy outcomes of Egyptian sheep. Small Ruminant Res. (2015), http://dx.doi.org/10.1016/j.smallrumres.2015.06.009
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Fig. 1. Means of number of lambs born per ewe conceived as affected by breed (Rahmani, R and Barki, B), parity (nulliparous, P1 and parous, P2) and post-mating nutrition (70%, N1, 100%, N2 and 130%, N3 of the maintenance requirements).
Fig. 2. Means of number of lambs weaned per ewe conceived as affected by breed (Rahmani, R and Barki, B), parity (nulliparous, P1 and parous, P2) and post-mating nutrition (70%, N1, 100%, N2 and 130%, N3 of the maintenance requirements).
Fig. 3. Means of number of ewes weaned per ewes conceived as affected by breed (Rahmani, R and Barki, B), parity (nulliparous, P1 and parous, P2) and post-mating nutrition (70%, N1, 100%, N2 and 130%, N3 of the maintenance requirements).
4. Discussion The current research examined the effects of breed, parity and post-mating nutritional level, during the first third of pregnancy, on reproductive wastage and pregnancy outcomes in two breeds of Egyptian sheep, Rahmani and Barki. Both of them had low prolificacy. However, Rahmani ewes was reported to have higher ovulation rate (1.29–1.57 vs. 1.16–1.20; Gabr et al., 1989; AbdelMageed and Abo El-Maaty, 2012) and litter size (1.12–148 vs. 1.00–1.16; Mokhtar et al., 1991; Aboul-Naga et al., 1992; AbdelMageed and Abo El-Maaty, 2012) than Barki ewes. No significant differences, in the present study, were observed between the two breeds for all the measured traits, except for back
fat at Day 140 of pregnancy. Barki ewes stored more back fat than Rahmani ewes in the last third of their pregnancy. However, both Rahmani and Barki ewes, at weaning, lost: body weight (−1.12 kg vs. −0.35 kg, respectively); body condition scores (−0.04 vs. −0.01, respectively); back fat thickness (−0.16 mm vs. −0.29 mm, respectively) and back muscle depth (−0.16 cm vs. −0.25 cm, respectively) compared to mating measurements. This emphasizes the importance of applying flushing practice for sheep dams before starting the breeding season. However, Kleemann and Walker (2005) concluded that, the reproductive wastage between mating and weaning in Merino was 42.4% of ova shed which is slightly less than that obtained in Rahmani and Barki ewes in the present study (47–55%).
Please cite this article in press as: Abdel-Mageed, I.I., El-Gawad, M.H.A., Effects of breed, parity and post-mating nutrition on reproductive wastage and pregnancy outcomes of Egyptian sheep. Small Ruminant Res. (2015), http://dx.doi.org/10.1016/j.smallrumres.2015.06.009
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Fig. 4. LSMeans (±SE) of kilograms of lambs born per ewe conceived as affected by breed (Rahmani, R and Barki, B), parity (nulliparous, P1 and parous, P2) and post-mating nutrition (70%, N1, 100%, N2 and 130%, N3 of the maintenance requirements).
Fig. 5. LSMeans (±SE) of kilograms of lambs weaned per ewe conceived as affected by breed (Rahmani, R and Barki, B), parity (nulliparous, P1 and parous, P2) and post-mating nutrition (70%, N1, 100%, N2 and 130%, N3 of the maintenance requirements).
Table 8 Effects of ewes’ breed (Rahmani, R and Barki, B), parity (nulliparous, P1 and parous, P2) and post-mating nutrition (70%, N1, 100%, N2 and 130%, N3 of the maintenance requirements) on reproductive wastage at different times of the reproductive cycle. Day 45 Breed 0.33 R 0.33 B Parity 0.32 P1 P2 0.37 Post-mating nutrition 0.45b N1 N2 0.22a N3 0.43b
Day 90
Day 140
Mid-suckling
Weaning
0.39 0.33
0.46 0.36
0.52 0.42
0.55 0.47
0.32 0.37
0.42 0.40
0.57 0.40
0.70a 0.42b
0.45b 0.22a 0.43b
0.50b 0.26a 0.48b
0.55b 0.28a 0.57b
0.62b 0.28a 0.64b
Columns, within the same treatment, followed by different superscripts, differ significantly from each other (P < 0.05). Reproductive wastage was measured as the difference between ovulation rate and number of embryos, fetuses, lambs born or lambs weaned, in relation to OR.
Parity of sheep significantly affected body weight, body condition score, reproductive wastage, lambs born/ewe conceived, lambs weaned/ewe conceived, ewes weaned/ewes conceived, kilograms born/ewe conceived and kilograms weaned/ewe conceived. The nulliparous group had lower values than the parous one for these traits except for reproductive wastage at weaning, it had higher rate. However, through the whole reproductive cycle, the nulliparous ewes lost 2.12 kg and 1.19 unit of body condition score compared to losing only 0.03 kg and 0.05 unit of body condition score in the parous sheep. Bari et al. (2003) concluded that parity of the recipient ewes did not affect embryo survival after transfer. This
is consistent with the non-significant effect of parity on embryonic mortality observed in our study. On the contrary, Yotov (2012) found significant effect for parity on embryonic mortality of sheep. However, results of Figs. 1–5 explained that, the measurements of lambs born/ewes conceived, lambs weaned/ewes conceived, ewes weaned/ewes conceived, kilograms born/ewes conceived and kilograms weaned/ewes conceived were significantly affected by parity of ewes. The parous ewes exceeded the nulliparous ones by 37, 92, 75, 42 and 71% of these traits, respectively. Ewe nutrition, during early pregnancy, had a very important role throughout its reproductive cycle. It regulates fetal and placental development and influences both short- and long-term health outcomes (Heasman et al., 1999). It also results in permanent structural and functional deficits in fetal and postnatal growth of animals (Igwebuike, 2010). It also conditions offspring adult health (Debus et al., 2012) and influence the weaning weight and the lactational performance of ewe offspring (Paten et al., 2013). Igwebuike (2010) concluded that, among intrauterine environmental factors, nutrition appeared to play the most critical role in influencing placental and fetal growth. Nutrient restriction during the first half of pregnancy impaired foetal growth (Igwebuike, 2010), associated with postnatal metabolic and endocrine disorders (Gilbert et al., 2005) and cardiovascular disorders (Hawkins et al., 2000). It also reduces uterine blood flow and uteroplacental glucose uptake (Bell, 1984) leading to fetal hypoglycemia and hypoxemia. Overfeeding, prior to and after mating, decreased the yield and quality of embryos after insemination (O’Callaghan and Boland, 1999) and impaired fetal growth (Igwebuike, 2010). As for body measurements, it is clear from our results that postmating nutrition of ewes significantly affected their body weights
Please cite this article in press as: Abdel-Mageed, I.I., El-Gawad, M.H.A., Effects of breed, parity and post-mating nutrition on reproductive wastage and pregnancy outcomes of Egyptian sheep. Small Ruminant Res. (2015), http://dx.doi.org/10.1016/j.smallrumres.2015.06.009
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and body condition scores at different stages of their reproductive ˜ cycle. Both Parr et al. (1986) and Munoz et al. (2009) previously supported these results. Parr et al. (1986) reported reduction in body weight of ewes by 4.9 kg in the under-nourished ewes (50% of maintenance requirements) compared to an increase of 1.8 kg in the over-nourished ones (150% of maintenance requirements) through ˜ et al. (2009) reported that live the first 35 days of pregnancy. Munoz weight and body condition score changes of ewes from Day 0 to Day 39 post-mating were −6.3 kg and −0.8 unit, +0.1 kg and −0.02 unit, +6.0 kg and +0.22 unit in the under-nourished (60% of maintenance requirements), medium-nourished (100% of maintenance requirements) and over-nourished ewes (200% of maintenance requirements), respectively. George et al. (2010) stated that, body condition scores were constant in the 3 nourished groups (100%, 125% and 150% of NRC) through the first 6 weeks of pregnancy, and increased in the subsequent weeks. Ewe-lambs body weight did not differ at 50 or 90 days of pregnancy in the moderately-fed sheep, but it increased at Day 130, while body weight increased gradually in the high-fed group through pregnancy (Caton et al., 2009). On Day 90 of pregnancy, Rooke et al. (2010) found that the low-fed group (75% of maintenance requirements) had lighter body weight and smaller body condition score, while maternal body weight did not differ at weaning. The data reviewed in our study indicate that post-mating nutritional practice significantly affected reproductive wastage at different stages of the reproductive cycle. Both undernutrition (0.45–0.62) and overnutrition (0.43–0.64) groups had higher reproductive wastages (P < 0.05) compared to the moderately-fed group (0.22–0.28). Abdel-Mageed et al. (2006) using Rahmani sheep observed about 30–35% atrophy of embryos and fetuses. Parr et al. (1986) found that, the effects of a 35 day of restricted feeding period (50% of maintenance requirements) were still evident in fetuses collected at Day 90 of gestation, but not at birth. Squires (2003) concluded that, animals which received inadequate nutrition, after mating, had a higher incidence of embryo mortality than those received adequate nutrition. This is in agreement with our results. Since undernutrition may induced changes in the endometrial sensitivity to steroid hormones at early stages of pregnancy that could adversely alter uterine environment to the detriment of embryo survival (Abecia et al., 2006). Also, it may reduce the ability of the embryo to secrete interferon-tau (IFN-), with a consequent increase in the production of PGF2␣ from the endometrium, which can initiate luteolysis (Gordon, 2004). On the other hand, the overnutrition seemed to adversely affect embryo survival. Parr et al. (1987) found 25–30% reduction in embryo survival arising from high-plane of feeding. It would appear that high food intakes, via their stimulatory effects on both hepatic blood flow and the metabolic clearance rate of progesterone (Parr et al., 1993), caused a decrease in plasma progesterone to levels that may compromise embryo growth and survival (Parr et al., 1987; Robinson, 1990). On the other hand, Sosa et al. (2009) found no effect of under nutrition (50% of maintenance requirements) from mating until 2 weeks after mating on the number of conceptuses recovered. Results of Figs. 1–5 indicate that, the measurements of lambs born/ewe conceived, lambs weaned/ewe conceived, ewes weaned/ewes conceived, kilograms born/ewe conceived and kilograms weaned/ewe conceived were significantly affected by post-mating nutrition. The moderately-fed ewes in the present study had higher values for these measurements. This is in agreement with results of Wallace et al., 2010 and Belkacemi et al. (2010). Wallace et al. (2010) recorded higher maternal weaning weight and adiposity score in the over-nourished and the mediumnourished adolescent sheep compared to the under-nourished ones. Belkacemi et al. (2010) stated that, suboptimal maternal nutrition yielded low birth weight, with substantial effect on the short-term morbidity of the newborn. On the other hand, Peel
et al. (2012) concluded that, excess nutrition during gestation in naturally-mated adolescent ewes did not affect birth weight or postnatal performance of offspring. Debus et al. (2012) stated that, maternal periconceptional undernutrition in a hardy breed does not significantly affect pregnancy rate, prolificacy, lamb birth weight, lamb mortality and growth rates. This is in contrast to previous reports in other breeds, suggesting that caution must be taken when extrapolating programming data between breeds and breeding conditions. As a conclusion for this paper, it is important to control the feeding allowance of ewes in early pregnancy to be around the maintenance requirements to decrease reproductive wastage and to increase pregnancy outcomes of Egyptian sheep. Conflict of interest There are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome. References Abdel-Mageed, I.I., Abo El-Maaty, A.M., 2012. The effect of backfat thickness at mating on the reproductive and productive performances of ewes. Small Ruminant Res. 105, 148–153. Abdel-Mageed, I., Ahmed, A.M., Barghouth, A.A., Barkawi, A.H., 2006. Economic evaluation of lamb production in Rahmani sheep under two regimes for superovulation. Egypt. J. Anim. Product. 43 (1), 41–48. Abecia, J.A., Sosa, C., Forcada, F., Meikle, A., 2006. The effect of undernutrition on the establishment of pregnancy in the ewe. Reprod. Nutr. Dev. 46, 367–378. Aboul-Naga, A.M., Aboul-Ela, M.B., Hassan, F., 1992. Manipulation of reproductive activity in subtropical sheep. Small Ruminant Res. 7, 151–160. Bari, F., Khalid, M., Haresign, W., Murray, A., Merrell, B., 2003. Factors affecting the survival of sheep embryos after transfer within a MOET program. Theriogenology 59 (5–6), 1265–1275. Belkacemi, L., Nelson, D.M., Desai, M., Ross, M.G., 2010. Maternal undernutrition influences placental-fetal development. Biol. Reprod. 83 (3), 325–331. Bell, A.W., 1984. Factors controlling placental and foetal growth and their effects on future production. In: Lindsay, D.R., Pearce, dan, D.T. (Eds.), Reproduction in Sheep. Camb. Univ. Press, Camb. Bolet, G., 1986. In: Sreenan, J.M., Diskin, M.G. (Ed.), Timing and Extent of Embryonic Mortality in Pigs, Sheep, and Goats: Genetic Variability: Pages 12–43 in Embryonic Mortality in Farm Animals. Dordrecht, Boston, MA, cited in Dixon et al., 2007. Caton, J.S., Reed, J.J., Aitken, R.P., Milne, J.S., Borowicz, P.P., Reynolds, L.P., Redmer, D.A., Wallace, J.M., 2009. Effects of maternal nutrition and stage of gestation on body weight, visceral organ mass, and indices of jejunal cellularity, proliferation, and vascularity in pregnant ewe lambs. J. Anim. Sci. 87 (1), 222–235. Debus, N., Chavatte-Palmer, P., Viudes, G., Camous, S., Roséfort, A., Hassoun, P., 2012. Maternal periconceptional undernutrition in Merinos d’Arles sheep: 1. Effects on pregnancy and reproduction results of dams and offspring growth performances. Theriogenology 15, 77 (7), 1453–1465. Dixon, A.B., Knight, M., Winkler, J.L., Marsh, D.J., Pate, J.L., Wilson, M.E., Dailey, R.A., Seidel, G., Inskeep, E.K., 2007. Patterns of late embryonic and fetal mortality and association with several factors in sheep. J. Anim. Sci. 85, 1274–1284. Gabr, M.G., Aboul-Naga, A.M., Aboul-Ela, M.B., El-Nakhla, S.M., 1989. Seasonal variation in ovulation rate, litter size and ova wastage in local Rahmani and Ossimi ewes. In: The 3rd Egyptian-British Conference on Animal, Fish and Poultry Production, 7–10 October, Alexandria, Egypt. George, L.A., Uthlaut, A.B., Long, N.M., Zhang, L., Ma, Y., Smith, D.T., Nathanielsz, P.W., Ford, S.P., 2010. Different levels of overnutrition and weight gain during pregnancy have differential effects on fetal growth and organ development. Reprod. Biol. Endocrinol. 8, 75. Gilbert, J.S., Lang, A.L., Grant, A.R., Nijland, M.J., 2005. Maternal nutrient restriction in sheep: hypertension and decreased nephron number in offspring at 9 months of age. J. Physiol. 565 (1), 137–147. Gordon, I., 2004. Reproductive Technologies in Farm Animals. CAB International Wallingford Oxon UK. Hawkins, P., Steyn, C., McGarrigle, H.H., Calder, N.A., Saito, T., Stratford, L.L., Noakes, D.E., Hansona, M.A., 2000. Cardiovascular and hypothalamic-pituitary-adrenal axis development in late gestation fetal sheep and young lambs following modest maternal nutrient restriction in early gestation. Reprod. Fertility Dev. 12 (7–8), 443–456. Heasman, L., Clarke, L., Stephenson, T.J., Symonds, M.E., 1999. The influence of maternal nutrient restriction in early to mid-pregnancy on placental and fetal development in sheep. Proc. Nutr. Soc. 58 (2), 283–288. Igwebuike, U.M., 2010. Impact of maternal nutrition on ovine foetoplacental development: a review of the role of insulin-like growth factors. Anim. Reprod. Sci. 121 (3–4), 189–196. Kleemann, D.O., Walker, S.K., 2005. Fertility in South Australian commercial Merino flocks: sources of reproductive wastage. Theriogenology 63 (8), 2075–2088.
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Mokhtar, M.M., Abdel Bary, H.T., Younis, A.A., Mabrouk, M.S., Abdel Aziz, H., 1991. Comparative study of two systems of production in Barki sheep. Egypt. J. Anim. Prod. 28 (1), 21–30. ˜ Munoz, C., Carson, A.F., McCoy, M.A., Dawson, L.E.R., Wylie, A.R.G., Gordon, A.W., 2009. Effects of plane of nutrition of ewes in early and mid-pregnancy on performance of the offspring: female reproduction and male carcass characteristics. J. Anim. Sci. 87, 3647–3655. NRC, 1985. Nutrient Requirements of Sheep, 6th ed. NRC, Washington, DC., USA. O’Callaghan, D., Boland, M.P., 1999. Nutritional effects on ovulation, embryo development and the establishment of pregnancy in ruminants. Anim. Sci. 68, 299–314. Parr, R.A., Williams, A.H., Campbell, I.P., Witcombe, G.F., Roberts, A.M., 1986. Low nutrition of ewes in early pregnancy and the residual effect on the offspring. J. Agric. Sci. Camberage 106, 81–87. Parr, R.A., Davis, I.F., Fairlough, R.J., Miles, M.A., 1987. Overfeeding during early pregnancy reduces peripheral progesterone concentration and pregnancy rate in sheep. J. Reprod. Fertility 80, 317–320. Parr, R.A., Davis, I.F., Miles, M.A., Squires, T.J., 1993. Feed intake affects metabolic clearance rate of progesterone in sheep. Res. Vet. Sci. 55 (3), 306–310. Paten, A.M., Kenyon, P.R., Lopez-Villalobos, N., Peterson, S.W., Jenkinson, C.M., Pain, S.J., Blair, H.T., 2013. Lactation Biology Symposium: maternal nutrition during early and mid-to-late pregnancy: comparative effects on milk production of twin-born ewe progeny during their first lactation. J. Anim. Sci. 91 (2), 676–684.
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Peel, R.K., Eckerle, G.J., Anthony, R.V., 2012. Effects of overfeeding naturally-mated adolescent ewes on maternal, fetal, and postnatal lamb growth. J. Anim. Sci. 90 (11), 3698–3708. Robinson, J.J., 1990. Nutrition in the reproduction of farm animals. Nutr. Res. Rev. 3, 253–276. Rooke, J.A., Houdijk, J.G., McIlvaney, K., Ashworth, C.J., Dwyer, C.M., 2010. Differential effects of maternal undernutrition between days 1 and 90 of pregnancy on ewe and lamb performance and lamb parasitism in hill or lowland breeds. J. Anim. Sci. 88 (12), 3833–3842. SAS, 2004. Ver. 9. 1. Qualification Tools User’s Guide. SAS Institute, Inc., Cary, NC, USA. Sosa, C., Abecia, J.A., Carriquiry, M., Vázquez, M.I., Fernández-Foren, A., Talmon, M., Forcada, F., Meikle, A., 2009. Effect of undernutrition on the uterine environment during maternal recognition of pregnancy in sheep. Reprod. Fertility Dev. 21 (7), 869–881. Squires, E.J., 2003. Applied Animal Endocrinology. CABI Publishing, Canada. Wallace, J.M., Milne, J.S., Aitken, R.P., 2010. Effect of weight and adiposity at conception and wide variations in gestational dietary intake on pregnancy outcome and early postnatal performance in young adolescent sheep. Biol. Reprod. 82 (2), 320–330. Yotov, S.A., 2012. Ultrasound diagnostics of late embryonic and foetal death in three sheep breeds. J. Vet. Adv. 2 (3), 120–125.
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Effects of breed, parity and post-mating nutrition on reproductive wastage and pregnancy outcomes of Egyptian sheep I.I. Abdel-Mageed ∗ , M.H. Abd El-Gawad Animal Production Department, Faculty of Agriculture, Cairo University, 12613 Giza, Egypt
a r t i c l e
i n f o
Article history: Received 28 December 2014 Received in revised form 8 May 2015 Accepted 12 June 2015 Available online xxx Keywords: Sheep Rahmani and Barki breeds Parity Post-mating nutrition Reproductive wastage Pregnancy outcomes
a b s t r a c t The aim of this work was to investigate the effects of breed, parity and post-mating nutrition on reproductive wastage and pregnancy outcomes in subtropical sheep. The experimental design was completely randomized and different groups of ewes were arranged factorially (2 × 2 × 3) according to the breed (Rahmani or Barki), parity of the ewes (nulliparous or parous) and post-mating nutritional regimen through the first 45 days of pregnancy (70%, 100% and 130% of maintenance requirements). Barki ewes had higher ability to store back fat through the last third of pregnancy compared to Rahmani ewes. The parous ewes had higher body weight gain and higher body condition score through pregnancy, while they lost lower body weight and body condition score through suckling. The under-nourished ewes had lower body weight, body condition score, back fat and back muscle throughout the whole reproductive cycle. Higher reproductive wastage at weaning was observed in the nulliparous ewes (70%) compared to the parous ones (42%). The under- and the over-nourished groups had a double-fold reproductive wastage through different times of reproductive cycle compared to those fed the maintenance requirements. The parous and the moderately-fed sheep had higher proportion of lambs born, kilograms born, lambs weaned, kilograms weaned and ewes weaned to ewes conceived. Therefore, to maximize lamb crop at weaning, it is important to control the feeding allowance of ewes in early pregnancy to be similar to the maintenance requirements. © 2015 Elsevier B.V. All rights reserved.
1. Introduction Production of healthy-weaned lambs is the main target of sheep breeders. It can be achieved by reducing the reproductive wastage of ewes throughout the different stages of the reproductive cycle. Number of weaned lambs and weaned weight depend on the reproductive wastage in ewes. The highest rate of embryo loss occurs during the time of maternal recognition of pregnancy (Squires, 2003). Dixon et al. (2007) concluded that, the complete pregnancy failure before day 25 accounted for 28%, and approximately 3–4% of the potential offspring were lost for each 20-d period of pregnancy beyond day 25. Reproductive wastage in the ewe from ovulation to parturition may range between 30% (Bolet, 1986) and 43.3% (Dixon et al., 2007). Kleemann and Walker (2005) observed reproductive wastage, at weaning, to be 42.4% of ova shed. Ewe nutrition during early pregnancy has a very important role throughout its reproductive cycle. It influences placental and fetal growth (Igwebuike,
∗ Corresponding author. Tel.: +20 1008715012 (mobile); fax: +20 2 37745574. E-mail addresses: [email protected], [email protected] (I.I. Abdel-Mageed).
2010), conditions offspring adult health (Debus et al., 2012) and influence the weaning weight and the lactational performance of ewe offspring (Paten et al., 2013). This paper investigated the effects of breed, parity and post-mating nutrition on reproductive wastage and pregnancy outcomes of two Egyptian sheep breeds, Rahmani and Barki. 2. Material and methods The present study was carried out at the experimental farm of the Animal Production Department, Faculty of Agriculture, Cairo University, Giza, Egypt, to investigate the effects of breed, parity and post-mating nutrition on reproductive wastage and pregnancy outcomes in two Egyptian sheep breeds (Rahmani [R] and Barki [B], n = 64, Table 1). The latitude of this location is 30◦ N and the longitude is 31◦ E. The initial body weight, age, body condition score, back fat thickness and back muscle depth of ewes, of the two breeds, are presented in Table 2. The breeding season extended from mid-May to mid-July. Immediately after mating, ewes within breed (Rahmani and Barki) and parity (nulliparous and parous), were allocated into three groups according to nutritional regimen that they consume daily;
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Table 1 Numbers of ewes per treatment used to study the effects of breed, parity and nutritional level during the first 45 days post-mating. Ewes breeds
Total
Rahmani
Barki
10 18
10 26
20 44
Post-mating nutritional level 8 70% of MR 11 100% of MR 9 130% of MR
12 12 12
20 23 21
Parity Nulliparous Parous
MR = maintenance requirements.
(1) 70% of maintenance requirements (MR), (2) 100% of MR and (3) 130% of MR. The nutritional regimen continued through the first 45 days after mating. While through the rest of the pregnancy and suckling periods, the three groups had the same regimen according to their feeding allowances that varied according to the stage of reproductive cycle (NRC, 1985). Ewes were maintained in semishaded pens, with drinking water freely available. Clover, clover hay, a concentrate mixture (13% CP and 0.65 kg TDN) and wheat straw were used in the diet formulation according to season. The concentrate mixture consisted of 55% yellow corn, 20% wheat bran, 10% cottonseed cake, 10% soybean meal, 2% limestone, 1.5% common salt, 1% minerals mixture, 0.4% sodium bicarbonate and 0.1% AD3E vitamins. Feeds chemical composition and nutritive value used for the experimental rations are presented in Table 3. Animals were synchronized for oestrus using two intramuscular injections of Estrumate (PGF2␣, each of 1 ml, 250 g Cloprostenol, Coopers Co., England) at an 11-day interval. Simultaneously with the 2nd treatment of Estrumate, fertile rams of the same breed were introduced in a ratio of 1:8. The traits measured on ewes at Days 45, 90, 140 of pregnancy, mid-suckling and weaning were body weight (BW), body condition score (BCS), back fat thickness (BF), back muscle depth (BM) and reproductive wastage (RW). The measurements of BW, BCS, BF and BM were calculated as the differences between the corresponding values at mating and at the different stages of the reproductive cycle. Numbers of lambs born (LB/EC), kilograms born (KgB/EC), lambs weaned (LW/EC), kilograms weaned (KgW/EC) and ewes weaned (EW/EC) per ewes conceived were also calculated. Reproductive wastage was measured as the difference between ovulation rate (OR) and number of embryos, fetuses, lambs born or lambs weaned, in relation to OR. The OR was measured by counting the number of corpora lutea at day 7 after mating. The measurements of BF, BM and OR were measured by ultrasonography, using a 6–8 MHz real-time, B-mode linear array ultrasound scanner (Model: Scanner 100 LC, Pie Medical Company, Masstricht, Netherlands) provided with transrectal transducer. The experimental design was completely randomized and the groups of ewes arranged factorially (2 × 2 × 3), according to the breed (Rahmani or Barki), parity of ewes (nulliparous or parous) and post-mating nutritional regimen (70% of MR, N1, 100% of MR, N2, or 130% of MR, N3) being the main effects. The interactions were
Table 3 Chemical composition and nutritive value of the experimental rations. Item
CFM
BH
WS
DM
89.2
91.68
90
Chemical composition, DM (%) 96.16 OM 14.11 CP 4.20 EE CF 8.51 69.34 NFE 3.84 Ash
83.99 10.31 2.54 31.43 39.71 16.01
85.21 3.79 1.79 44.87 34.76 14.79
Fiber fraction (%) NDF ADF ADL Hemicellulose Cellulose
30.73 8.84 2.31 21.89 6.53
45.90 31.05 7.44 14.85 23.61
81.97 53.68 6.89 28.29 46.79
Nutritive Value (%) DCP TDN
13 65
9 48
1 44
CFM: The concentrate feed mixture, BH: berseem hay, WS: Wheat straw. Hemicellulose = NDF-ADF, Cellulose = ADF-ADL.
considered and no significant differences were observed. Data of the measured traits were analyzed using the SAS GLM procedure. The Least Squares Means (LSM) were obtained for the BW, BCS, BF, BM, KgB/EC and KgW/EC traits. While the RW, LB/EC, LW/EC and EW/EC traits were analyzed using the chi-square CATMOD procedure. The Tukey’s Studentized Range (HSD) Test was used to detect differences among means. The significance level was set at P < 0.05 (SAS, 2004). 3. Results The effects of ewes’ breed, parity and post-mating nutrition on body weight (BW), body condition score (BCS), back fat thickness (BF) and back muscle depth (BM) are presented in Tables 4–7. No significant differences were observed between Rahmani and Barki ewes for BW, BCS and BM at the different stages of the reproductive cycle. Barki had higher ability to store backfat than Rahmani ewes through the last third of pregnancy. The effect of parity was significant in both BW and BCS. Parous ewes gained higher weights and more BCS units through pregnancy. They also lost less weights and BCS units throughout the suckling period. The effect of post-mating nutrition on ewes body measurements was significant through the first two thirds of pregnancy. The under-nourished group had lower (P < 0.05) BW, BCS, BF and BM at Day 45 post conception. This significant effect extended to Day 90 but it disappeared at lambing. The effect of both BW and BCS was significant again at mid-suckling, where the under-nourished group had lower values than the other two groups. The effects of ewes’ breed, parity and post-mating nutrition on reproductive wastage (RW) are presented in Table 8. Breed of sheep had no significant effect on RW. Higher RW, at weaning, was observed in the nulliparous ewes compared to the parous ones (70% vs. 42%, respectively). The under- and the over-nourished groups
Table 2 Means and SD of body weight (BW), age, body condition score (BCS), back fat thickness (BF) and back muscle depth (BM) of two breeds of Egyptian ewes at the beginning of the study. N
Rahmani Barki
28 36
BW (kg)
Age (years)
BCS (unit)
BF (mm)
BM (cm)
Mean
SD
Mean
SD
Mean
SD
Mean
SD
Mean
SD
37.64 34.99
4.87 4.72
3.11 3.31
0.98 1.02
2.41 2.73
0.47 0.41
1.41 1.72
0.63 0.69
1.76 1.98
0.32 0.42
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Table 4 Effects of ewes’ breed (Rahmani, R and Barki, B), parity (nulliparous, P1 and parous, P2) and post-mating nutrition (70%, N1, 100%, N2 and 130%, N3 of the maintenance requirements) on body weight difference (LSM ± SE, kg) at different times of the reproductive. Day 45 Breed R B Parity P1 P2 Post-mating nutrition N1 N2 N3
Day 90
Day 140
Mid-suckling
Weaning
0.11 ± 0.25 −0.08 ± 0.24
2.05 ± 0.45 1.49 ± 0.43
5.11 ± 0.67 6.07 ± 0.65
0.09 ± 0.75 −0.25 ± 0.72
−1.12 ± 0.74 −0.35 ± 0.71
−0.97 ± 0.28b 0.44 ± 0.18a
0.15 ± 0.49b 2.45 ± 0.33a
3.12 ± 0.73b 6.08 ± 0.49a
−2.00 ± 0.82b 0.76 ± 0.54a
−2.12 ± 0.80b −0.03 ± 0.53a
−2.20 ± 0.25c 0.17 ± 0.26b 1.90 ± 0.26a
−0.02 ± 0.45c 1.90 ± 0.46b 3.20 ± 0.47a
4.77 ± 0.67 5.98 ± 0.69 6.07 ± 0.70
−1.40 ± 0.75b 0.78 ± 0.77a 0.17 ± 0.78a
−1.52 ± 0.74 −0.17 ± 0.76 −0.45 ± 0.77
Columns, within the same treatment, followed by different superscripts, differ significantly from each other (P < 0.05).
Table 5 Effects of ewes’ breed (Rahmani, R and Barki, B), parity (nulliparous, P1 and parous, P2) and post-mating nutrition (70%, N1, 100%, N2 and 130%, N3 of the maintenance requirements) on body condition score difference (LSM ± SE, unit) at different times of the reproductive cycle. Day 45 Breed R B Parity P1 P2 Post-mating nutrition N1 N2 N3
Day 90
Day 140
Mid-suckling
Weaning
0.06 ± 0.05 0.05 ± 0.05
0.24 ± 0.06 0.22 ± 0.05
0.47 ± 0.07 0.43 ± 0.07
0.18 ± 0.07 0.11 ± 0.07
−0.04 ± 0.08 −0.01 ± 0.08
0.00 ± 0.06 0.08 ± 0.04
0.15 ± 0.06 0.26 ± 0.04
0.26 ± 0.08b 0.53 ± 0.05a
0.02 ± 0.08b 0.20 ± 0.05a
−1.19 ± 0.09b 0.05 ± 0.06a
−0.26 ± 0.05c −0.04 ± 0.05b 0.44 ± 0.05a
0.04 ± 0.06c 0.22 ± 0.06b 0.41 ± 0.06a
0.36 ± 0.07 0.50 ± 0.08 0.47 ± 0.08
0.02 ± 0.08b 0.26 ± 0.08a 0.13 ± 0.08ab
−0.09 ± 0.08 0.08 ± 0.08 −0.07 ± 0.09
Columns, within the same treatment, followed by different superscripts, differ significantly from each other (P < 0.05).
Table 6 Effects of ewes’ breed (Rahmani, R and Barki, B), parity (nulliparous, P1 and parous, P2) and post-mating nutrition (70%, N1, 100%, N2 and 130%, N3 of the maintenance requirements) on back fat thickness difference (LSM ± SE, mm) at different times of the reproductive cycle. Day 45 Breed R B Parity P1 P2 Post-mating nutrition N1 N2 N3
Day 90
Day 140
Mid-suckling
Weaning
0.00 ± 0.05 0.02 ± 0.05
0.03 ± 0.08 0.08 ± 0.08
0.71 ± 0.17b 1.16 ± 0.16a
0.21 ± 0.35 0.21 ± 0.34
−0.16 ± 0.10 −0.29 ± 0.10
−0.03 ± 0.06 0.03 ± 0.04
0.02 ± 0.09 0.08 ± 0.06
1.05 ± 0.19 0.93 ± 0.12
0.16 ± 0.38 0.23 ± 0.25
−0.14 ± 0.11 −0.28 ± 0.07
−0.17 ± 0.05c 0.00 ± 0.06b 0.21 ± 0.06a
−0.15 ± 0.08b 0.13 ± 0.09a 0.19 ± 0.09a
1.14 ± 0.17 0.88 ± 0.17 0.89 ± 0.18
0.41 ± 0.35 0.04 ± 0.36 0.20 ± 0.36
−0.25 ± 0.10 −0.14 ± 0.10 −0.32 ± 0.11
Columns, within the same treatment, followed by different superscripts, differ significantly from each other (P < 0.05).
Table 7 Effects of ewes’ breed (Rahmani, R and Barki, B), parity (nulliparous, P1 and parous, P2) and post-mating nutrition (70%, N1, 100%, N2 and 130%, N3 of the maintenance requirements) on back muscle depth difference (LSM ± SE, cm) at different times of the reproductive cycle. Day 45 Breed R B Parity P1 P2 Post-mating nutrition N1 N2 N3
Day 90
Day 140
Mid-suckling
Weaning
0.03 ± 0.04 −0.01 ± 0.04
0.14 ± 0.06 0.06 ± 0.06
0.29 ± 0.09 0.22 ± 0.09
−0.12 ± 0.07 −0.25 ± 0.07
−0.16 ± 0.07 −0.25 ± 0.07
0.00 ± 0.04 0.00 ± 0.03
0.11 ± 0.06 0.08 ± 0.04
0.27 ± 0.10 0.24 ± 0.06
−0.14 ± 0.08 −0.24 ± 0.05
−0.22 ± 0.08 −0.20 ± 0.05
−0.18 ± 0.04c 0.00 ± 0.04b 0.18 ± 0.04a
−0.05 ± 0.06c 0.09 ± 0.06b 0.24 ± 0.06a
0.16 ± 0.09 0.23 ± 0.09 0.35 ± 0.09
−0.26 ± 0.07 −0.13 ± 0.07 −0.23 ± 0.07
−0.25 ± 0.07 −0.12 ± 0.08 −0.27 ± 0.06
Columns, within the same treatment, followed by different superscripts, differ significantly from each other (P < 0.05).
had a double-fold RW through the different stages of reproductive cycle compared to those fed the maintenance requirements. The effects of ewes’ breed, parity and post-mating nutritional level on LB/EC, LW/EC, EW/EC, KgB/EC and KgW/EC are presented
in Figs. 1–5. Both parity and post-mating nutrition significantly affected these traits. The parous ewes had higher values than the nulliparous ones. Also the moderately-fed group had higher values than the under- or the over-fed groups.
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Fig. 1. Means of number of lambs born per ewe conceived as affected by breed (Rahmani, R and Barki, B), parity (nulliparous, P1 and parous, P2) and post-mating nutrition (70%, N1, 100%, N2 and 130%, N3 of the maintenance requirements).
Fig. 2. Means of number of lambs weaned per ewe conceived as affected by breed (Rahmani, R and Barki, B), parity (nulliparous, P1 and parous, P2) and post-mating nutrition (70%, N1, 100%, N2 and 130%, N3 of the maintenance requirements).
Fig. 3. Means of number of ewes weaned per ewes conceived as affected by breed (Rahmani, R and Barki, B), parity (nulliparous, P1 and parous, P2) and post-mating nutrition (70%, N1, 100%, N2 and 130%, N3 of the maintenance requirements).
4. Discussion The current research examined the effects of breed, parity and post-mating nutritional level, during the first third of pregnancy, on reproductive wastage and pregnancy outcomes in two breeds of Egyptian sheep, Rahmani and Barki. Both of them had low prolificacy. However, Rahmani ewes was reported to have higher ovulation rate (1.29–1.57 vs. 1.16–1.20; Gabr et al., 1989; AbdelMageed and Abo El-Maaty, 2012) and litter size (1.12–148 vs. 1.00–1.16; Mokhtar et al., 1991; Aboul-Naga et al., 1992; AbdelMageed and Abo El-Maaty, 2012) than Barki ewes. No significant differences, in the present study, were observed between the two breeds for all the measured traits, except for back
fat at Day 140 of pregnancy. Barki ewes stored more back fat than Rahmani ewes in the last third of their pregnancy. However, both Rahmani and Barki ewes, at weaning, lost: body weight (−1.12 kg vs. −0.35 kg, respectively); body condition scores (−0.04 vs. −0.01, respectively); back fat thickness (−0.16 mm vs. −0.29 mm, respectively) and back muscle depth (−0.16 cm vs. −0.25 cm, respectively) compared to mating measurements. This emphasizes the importance of applying flushing practice for sheep dams before starting the breeding season. However, Kleemann and Walker (2005) concluded that, the reproductive wastage between mating and weaning in Merino was 42.4% of ova shed which is slightly less than that obtained in Rahmani and Barki ewes in the present study (47–55%).
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Fig. 4. LSMeans (±SE) of kilograms of lambs born per ewe conceived as affected by breed (Rahmani, R and Barki, B), parity (nulliparous, P1 and parous, P2) and post-mating nutrition (70%, N1, 100%, N2 and 130%, N3 of the maintenance requirements).
Fig. 5. LSMeans (±SE) of kilograms of lambs weaned per ewe conceived as affected by breed (Rahmani, R and Barki, B), parity (nulliparous, P1 and parous, P2) and post-mating nutrition (70%, N1, 100%, N2 and 130%, N3 of the maintenance requirements).
Table 8 Effects of ewes’ breed (Rahmani, R and Barki, B), parity (nulliparous, P1 and parous, P2) and post-mating nutrition (70%, N1, 100%, N2 and 130%, N3 of the maintenance requirements) on reproductive wastage at different times of the reproductive cycle. Day 45 Breed 0.33 R 0.33 B Parity 0.32 P1 P2 0.37 Post-mating nutrition 0.45b N1 N2 0.22a N3 0.43b
Day 90
Day 140
Mid-suckling
Weaning
0.39 0.33
0.46 0.36
0.52 0.42
0.55 0.47
0.32 0.37
0.42 0.40
0.57 0.40
0.70a 0.42b
0.45b 0.22a 0.43b
0.50b 0.26a 0.48b
0.55b 0.28a 0.57b
0.62b 0.28a 0.64b
Columns, within the same treatment, followed by different superscripts, differ significantly from each other (P < 0.05). Reproductive wastage was measured as the difference between ovulation rate and number of embryos, fetuses, lambs born or lambs weaned, in relation to OR.
Parity of sheep significantly affected body weight, body condition score, reproductive wastage, lambs born/ewe conceived, lambs weaned/ewe conceived, ewes weaned/ewes conceived, kilograms born/ewe conceived and kilograms weaned/ewe conceived. The nulliparous group had lower values than the parous one for these traits except for reproductive wastage at weaning, it had higher rate. However, through the whole reproductive cycle, the nulliparous ewes lost 2.12 kg and 1.19 unit of body condition score compared to losing only 0.03 kg and 0.05 unit of body condition score in the parous sheep. Bari et al. (2003) concluded that parity of the recipient ewes did not affect embryo survival after transfer. This
is consistent with the non-significant effect of parity on embryonic mortality observed in our study. On the contrary, Yotov (2012) found significant effect for parity on embryonic mortality of sheep. However, results of Figs. 1–5 explained that, the measurements of lambs born/ewes conceived, lambs weaned/ewes conceived, ewes weaned/ewes conceived, kilograms born/ewes conceived and kilograms weaned/ewes conceived were significantly affected by parity of ewes. The parous ewes exceeded the nulliparous ones by 37, 92, 75, 42 and 71% of these traits, respectively. Ewe nutrition, during early pregnancy, had a very important role throughout its reproductive cycle. It regulates fetal and placental development and influences both short- and long-term health outcomes (Heasman et al., 1999). It also results in permanent structural and functional deficits in fetal and postnatal growth of animals (Igwebuike, 2010). It also conditions offspring adult health (Debus et al., 2012) and influence the weaning weight and the lactational performance of ewe offspring (Paten et al., 2013). Igwebuike (2010) concluded that, among intrauterine environmental factors, nutrition appeared to play the most critical role in influencing placental and fetal growth. Nutrient restriction during the first half of pregnancy impaired foetal growth (Igwebuike, 2010), associated with postnatal metabolic and endocrine disorders (Gilbert et al., 2005) and cardiovascular disorders (Hawkins et al., 2000). It also reduces uterine blood flow and uteroplacental glucose uptake (Bell, 1984) leading to fetal hypoglycemia and hypoxemia. Overfeeding, prior to and after mating, decreased the yield and quality of embryos after insemination (O’Callaghan and Boland, 1999) and impaired fetal growth (Igwebuike, 2010). As for body measurements, it is clear from our results that postmating nutrition of ewes significantly affected their body weights
Please cite this article in press as: Abdel-Mageed, I.I., El-Gawad, M.H.A., Effects of breed, parity and post-mating nutrition on reproductive wastage and pregnancy outcomes of Egyptian sheep. Small Ruminant Res. (2015), http://dx.doi.org/10.1016/j.smallrumres.2015.06.009
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and body condition scores at different stages of their reproductive ˜ cycle. Both Parr et al. (1986) and Munoz et al. (2009) previously supported these results. Parr et al. (1986) reported reduction in body weight of ewes by 4.9 kg in the under-nourished ewes (50% of maintenance requirements) compared to an increase of 1.8 kg in the over-nourished ones (150% of maintenance requirements) through ˜ et al. (2009) reported that live the first 35 days of pregnancy. Munoz weight and body condition score changes of ewes from Day 0 to Day 39 post-mating were −6.3 kg and −0.8 unit, +0.1 kg and −0.02 unit, +6.0 kg and +0.22 unit in the under-nourished (60% of maintenance requirements), medium-nourished (100% of maintenance requirements) and over-nourished ewes (200% of maintenance requirements), respectively. George et al. (2010) stated that, body condition scores were constant in the 3 nourished groups (100%, 125% and 150% of NRC) through the first 6 weeks of pregnancy, and increased in the subsequent weeks. Ewe-lambs body weight did not differ at 50 or 90 days of pregnancy in the moderately-fed sheep, but it increased at Day 130, while body weight increased gradually in the high-fed group through pregnancy (Caton et al., 2009). On Day 90 of pregnancy, Rooke et al. (2010) found that the low-fed group (75% of maintenance requirements) had lighter body weight and smaller body condition score, while maternal body weight did not differ at weaning. The data reviewed in our study indicate that post-mating nutritional practice significantly affected reproductive wastage at different stages of the reproductive cycle. Both undernutrition (0.45–0.62) and overnutrition (0.43–0.64) groups had higher reproductive wastages (P < 0.05) compared to the moderately-fed group (0.22–0.28). Abdel-Mageed et al. (2006) using Rahmani sheep observed about 30–35% atrophy of embryos and fetuses. Parr et al. (1986) found that, the effects of a 35 day of restricted feeding period (50% of maintenance requirements) were still evident in fetuses collected at Day 90 of gestation, but not at birth. Squires (2003) concluded that, animals which received inadequate nutrition, after mating, had a higher incidence of embryo mortality than those received adequate nutrition. This is in agreement with our results. Since undernutrition may induced changes in the endometrial sensitivity to steroid hormones at early stages of pregnancy that could adversely alter uterine environment to the detriment of embryo survival (Abecia et al., 2006). Also, it may reduce the ability of the embryo to secrete interferon-tau (IFN-), with a consequent increase in the production of PGF2␣ from the endometrium, which can initiate luteolysis (Gordon, 2004). On the other hand, the overnutrition seemed to adversely affect embryo survival. Parr et al. (1987) found 25–30% reduction in embryo survival arising from high-plane of feeding. It would appear that high food intakes, via their stimulatory effects on both hepatic blood flow and the metabolic clearance rate of progesterone (Parr et al., 1993), caused a decrease in plasma progesterone to levels that may compromise embryo growth and survival (Parr et al., 1987; Robinson, 1990). On the other hand, Sosa et al. (2009) found no effect of under nutrition (50% of maintenance requirements) from mating until 2 weeks after mating on the number of conceptuses recovered. Results of Figs. 1–5 indicate that, the measurements of lambs born/ewe conceived, lambs weaned/ewe conceived, ewes weaned/ewes conceived, kilograms born/ewe conceived and kilograms weaned/ewe conceived were significantly affected by post-mating nutrition. The moderately-fed ewes in the present study had higher values for these measurements. This is in agreement with results of Wallace et al., 2010 and Belkacemi et al. (2010). Wallace et al. (2010) recorded higher maternal weaning weight and adiposity score in the over-nourished and the mediumnourished adolescent sheep compared to the under-nourished ones. Belkacemi et al. (2010) stated that, suboptimal maternal nutrition yielded low birth weight, with substantial effect on the short-term morbidity of the newborn. On the other hand, Peel
et al. (2012) concluded that, excess nutrition during gestation in naturally-mated adolescent ewes did not affect birth weight or postnatal performance of offspring. Debus et al. (2012) stated that, maternal periconceptional undernutrition in a hardy breed does not significantly affect pregnancy rate, prolificacy, lamb birth weight, lamb mortality and growth rates. This is in contrast to previous reports in other breeds, suggesting that caution must be taken when extrapolating programming data between breeds and breeding conditions. As a conclusion for this paper, it is important to control the feeding allowance of ewes in early pregnancy to be around the maintenance requirements to decrease reproductive wastage and to increase pregnancy outcomes of Egyptian sheep. Conflict of interest There are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome. References Abdel-Mageed, I.I., Abo El-Maaty, A.M., 2012. The effect of backfat thickness at mating on the reproductive and productive performances of ewes. Small Ruminant Res. 105, 148–153. Abdel-Mageed, I., Ahmed, A.M., Barghouth, A.A., Barkawi, A.H., 2006. Economic evaluation of lamb production in Rahmani sheep under two regimes for superovulation. Egypt. J. Anim. Product. 43 (1), 41–48. Abecia, J.A., Sosa, C., Forcada, F., Meikle, A., 2006. The effect of undernutrition on the establishment of pregnancy in the ewe. Reprod. Nutr. Dev. 46, 367–378. Aboul-Naga, A.M., Aboul-Ela, M.B., Hassan, F., 1992. Manipulation of reproductive activity in subtropical sheep. Small Ruminant Res. 7, 151–160. Bari, F., Khalid, M., Haresign, W., Murray, A., Merrell, B., 2003. Factors affecting the survival of sheep embryos after transfer within a MOET program. Theriogenology 59 (5–6), 1265–1275. Belkacemi, L., Nelson, D.M., Desai, M., Ross, M.G., 2010. Maternal undernutrition influences placental-fetal development. Biol. Reprod. 83 (3), 325–331. Bell, A.W., 1984. Factors controlling placental and foetal growth and their effects on future production. In: Lindsay, D.R., Pearce, dan, D.T. (Eds.), Reproduction in Sheep. Camb. Univ. Press, Camb. Bolet, G., 1986. In: Sreenan, J.M., Diskin, M.G. (Ed.), Timing and Extent of Embryonic Mortality in Pigs, Sheep, and Goats: Genetic Variability: Pages 12–43 in Embryonic Mortality in Farm Animals. Dordrecht, Boston, MA, cited in Dixon et al., 2007. Caton, J.S., Reed, J.J., Aitken, R.P., Milne, J.S., Borowicz, P.P., Reynolds, L.P., Redmer, D.A., Wallace, J.M., 2009. Effects of maternal nutrition and stage of gestation on body weight, visceral organ mass, and indices of jejunal cellularity, proliferation, and vascularity in pregnant ewe lambs. J. Anim. Sci. 87 (1), 222–235. Debus, N., Chavatte-Palmer, P., Viudes, G., Camous, S., Roséfort, A., Hassoun, P., 2012. Maternal periconceptional undernutrition in Merinos d’Arles sheep: 1. Effects on pregnancy and reproduction results of dams and offspring growth performances. Theriogenology 15, 77 (7), 1453–1465. Dixon, A.B., Knight, M., Winkler, J.L., Marsh, D.J., Pate, J.L., Wilson, M.E., Dailey, R.A., Seidel, G., Inskeep, E.K., 2007. Patterns of late embryonic and fetal mortality and association with several factors in sheep. J. Anim. Sci. 85, 1274–1284. Gabr, M.G., Aboul-Naga, A.M., Aboul-Ela, M.B., El-Nakhla, S.M., 1989. Seasonal variation in ovulation rate, litter size and ova wastage in local Rahmani and Ossimi ewes. In: The 3rd Egyptian-British Conference on Animal, Fish and Poultry Production, 7–10 October, Alexandria, Egypt. George, L.A., Uthlaut, A.B., Long, N.M., Zhang, L., Ma, Y., Smith, D.T., Nathanielsz, P.W., Ford, S.P., 2010. Different levels of overnutrition and weight gain during pregnancy have differential effects on fetal growth and organ development. Reprod. Biol. Endocrinol. 8, 75. Gilbert, J.S., Lang, A.L., Grant, A.R., Nijland, M.J., 2005. Maternal nutrient restriction in sheep: hypertension and decreased nephron number in offspring at 9 months of age. J. Physiol. 565 (1), 137–147. Gordon, I., 2004. Reproductive Technologies in Farm Animals. CAB International Wallingford Oxon UK. Hawkins, P., Steyn, C., McGarrigle, H.H., Calder, N.A., Saito, T., Stratford, L.L., Noakes, D.E., Hansona, M.A., 2000. Cardiovascular and hypothalamic-pituitary-adrenal axis development in late gestation fetal sheep and young lambs following modest maternal nutrient restriction in early gestation. Reprod. Fertility Dev. 12 (7–8), 443–456. Heasman, L., Clarke, L., Stephenson, T.J., Symonds, M.E., 1999. The influence of maternal nutrient restriction in early to mid-pregnancy on placental and fetal development in sheep. Proc. Nutr. Soc. 58 (2), 283–288. Igwebuike, U.M., 2010. Impact of maternal nutrition on ovine foetoplacental development: a review of the role of insulin-like growth factors. Anim. Reprod. Sci. 121 (3–4), 189–196. Kleemann, D.O., Walker, S.K., 2005. Fertility in South Australian commercial Merino flocks: sources of reproductive wastage. Theriogenology 63 (8), 2075–2088.
Please cite this article in press as: Abdel-Mageed, I.I., El-Gawad, M.H.A., Effects of breed, parity and post-mating nutrition on reproductive wastage and pregnancy outcomes of Egyptian sheep. Small Ruminant Res. (2015), http://dx.doi.org/10.1016/j.smallrumres.2015.06.009
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ARTICLE IN PRESS I.I. Abdel-Mageed, M.H.A. El-Gawad / Small Ruminant Research xxx (2015) xxx–xxx
Mokhtar, M.M., Abdel Bary, H.T., Younis, A.A., Mabrouk, M.S., Abdel Aziz, H., 1991. Comparative study of two systems of production in Barki sheep. Egypt. J. Anim. Prod. 28 (1), 21–30. ˜ Munoz, C., Carson, A.F., McCoy, M.A., Dawson, L.E.R., Wylie, A.R.G., Gordon, A.W., 2009. Effects of plane of nutrition of ewes in early and mid-pregnancy on performance of the offspring: female reproduction and male carcass characteristics. J. Anim. Sci. 87, 3647–3655. NRC, 1985. Nutrient Requirements of Sheep, 6th ed. NRC, Washington, DC., USA. O’Callaghan, D., Boland, M.P., 1999. Nutritional effects on ovulation, embryo development and the establishment of pregnancy in ruminants. Anim. Sci. 68, 299–314. Parr, R.A., Williams, A.H., Campbell, I.P., Witcombe, G.F., Roberts, A.M., 1986. Low nutrition of ewes in early pregnancy and the residual effect on the offspring. J. Agric. Sci. Camberage 106, 81–87. Parr, R.A., Davis, I.F., Fairlough, R.J., Miles, M.A., 1987. Overfeeding during early pregnancy reduces peripheral progesterone concentration and pregnancy rate in sheep. J. Reprod. Fertility 80, 317–320. Parr, R.A., Davis, I.F., Miles, M.A., Squires, T.J., 1993. Feed intake affects metabolic clearance rate of progesterone in sheep. Res. Vet. Sci. 55 (3), 306–310. Paten, A.M., Kenyon, P.R., Lopez-Villalobos, N., Peterson, S.W., Jenkinson, C.M., Pain, S.J., Blair, H.T., 2013. Lactation Biology Symposium: maternal nutrition during early and mid-to-late pregnancy: comparative effects on milk production of twin-born ewe progeny during their first lactation. J. Anim. Sci. 91 (2), 676–684.
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Peel, R.K., Eckerle, G.J., Anthony, R.V., 2012. Effects of overfeeding naturally-mated adolescent ewes on maternal, fetal, and postnatal lamb growth. J. Anim. Sci. 90 (11), 3698–3708. Robinson, J.J., 1990. Nutrition in the reproduction of farm animals. Nutr. Res. Rev. 3, 253–276. Rooke, J.A., Houdijk, J.G., McIlvaney, K., Ashworth, C.J., Dwyer, C.M., 2010. Differential effects of maternal undernutrition between days 1 and 90 of pregnancy on ewe and lamb performance and lamb parasitism in hill or lowland breeds. J. Anim. Sci. 88 (12), 3833–3842. SAS, 2004. Ver. 9. 1. Qualification Tools User’s Guide. SAS Institute, Inc., Cary, NC, USA. Sosa, C., Abecia, J.A., Carriquiry, M., Vázquez, M.I., Fernández-Foren, A., Talmon, M., Forcada, F., Meikle, A., 2009. Effect of undernutrition on the uterine environment during maternal recognition of pregnancy in sheep. Reprod. Fertility Dev. 21 (7), 869–881. Squires, E.J., 2003. Applied Animal Endocrinology. CABI Publishing, Canada. Wallace, J.M., Milne, J.S., Aitken, R.P., 2010. Effect of weight and adiposity at conception and wide variations in gestational dietary intake on pregnancy outcome and early postnatal performance in young adolescent sheep. Biol. Reprod. 82 (2), 320–330. Yotov, S.A., 2012. Ultrasound diagnostics of late embryonic and foetal death in three sheep breeds. J. Vet. Adv. 2 (3), 120–125.
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