Age at puberty and fertility of Rahmani sheep fed on biological inoculated corn silage

Annals of Agricultural Science (2013) 58(2), 163–172

Faculty of Agriculture, Ain Shams University

Annals of Agricultural Science www.elsevier.com/locate/aoas

ORIGINAL ARTICLE

Age at puberty and fertility of Rahmani sheep fed on biological inoculated corn silage E.I. Khalifa a,*, M.E. Ahmed a, Y.H. Hafez a, O.A. El-Zolaky a, K.M. Bahera b, A.A. Abido b a b

Animal Production Research Institute, Ministry of Agriculture, Dokki, Giza, Egypt National Research Center – Animal Production, Dokki, Giza, Egypt

Received 1 April 2013; accepted 14 April 2013 Available online 5 September 2013

KEYWORDS Sheep; Microbial inoculation corn silage; Pubertal age; Production; Fertility

Abstract The present study aimed to investigate the effect of microbial inoculation adding to corn silage on productive and reproductive performance of sheep. The weaning male and female lambs were fed separately in four groups received a basal diet consisting of concentrate feed mixture (CFM) plus wheat straw (WS). The control group of two sex lambs (n = 7 males and n = 8 females) was fed R1 included CFM + WS + corn silage (CS), whereas treatment group of two sex lambs (n = 7 males and 8 females) nourished R2 contained CFM+WS+ microbial inoculation corn silage (MICS). Both R1 and R2 rations were adjusted every 2 weeks according feeding requirements. The measurements as body weight, body condition score, progesterone, and testosterone at puberty, semen collection at puberty. The fertility test was assayed with mature rams and ewes. The obtained results showed that the average body weight and body condition score of male and female lambs were higher (P < 0.05) with R2 than R1. Both male and female lambs supplied R2 reached puberty faster and sexual hormones (testosterone and progesterone) developed earlier than lambs given R1. The ages at puberty and testosterone hormone were 32.14 weeks and 3.12 ng/ml for R2 lambs while 36.72 weeks and 2.81 ng/ml for R1 lambs, respectively. Age at puberty and progesterone concentration averaged 34.12 weeks and 1.89 ng/ml with female lambs presented R2, while female lambs fed R1 achieved 38.51 weeks and 1.53 ng/ml, respectively. Moreover, male lambs in R2 group were produced higher quality semen (P < 0.05) than those in R1 group. The ram nourished R2 displayed (P < 0.05) enhanced fertility 79.17% compared with R1 70.83%. The pregnancy rate and litter size with ewes received R2 were higher 91.67% and 1.30 than ewes fed R1 83.33% and 1.00, respectively. As a result, it may be concluded that addition of microbial inoculation to corm silage had positive effect on fermentation quality of silage and improved palatability

* Corresponding author. Tel.: +20 (202) 44441172. E-mail address: [email protected] (E.I. Khalifa). Peer review under responsibility of Faculty of Agriculture, Ain-Shams University.

Production and hosting by Elsevier 0570-1783 ª 2013 Production and hosting by Elsevier B.V. on behalf of Faculty of Agriculture, Ain Shams University. http://dx.doi.org/10.1016/j.aoas.2013.07.003

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E.I. Khalifa et al. and nutritive value that reflected on productive and reproductive performance of sheep. ª 2013 Production and hosting by Elsevier B.V. on behalf of Faculty of Agriculture, Ain Shams University.

Introduction

Materials and methods

Rahmani sheep produces good quality meat and respond well to genetic improvement through selection. They are also known for their ability to walk long distances and the ability to cope with harsh environmental conditions such as long periods of drought and high temperatures. Therefore, they had been introduced in several Egyptian areas. Characterization of puberty and early sexual development is a valuable tool for selection within the males of a given breed. The onset of puberty in sheep is influenced by genetic and environmental factors such as breed climate nutrition and strain differences. Workers on age at puberty agree that the early age is associated with the time of birth and the nutritional planes. Differences in sexual puberty behavior among ram and ewe lambs have been recognized for many years. Puberty is difficult to define because of the complexity of the mechanisms of growth development occurrence during puberty and maturity. Hafez and Hafez (2000) found that puberty is basically the result of gradual adjustment between increasing gonadotropic activity and ability of gonads to simultaneously assume steroidogenesis and gametogenesis. Male and female lambs with high scores for early puberty and distinctive sexual behavior can improve flock fertility during breeding and indirectly improve the genetics (Ibarra et al., 2000). Mating behavior and reproductive success is hormone dependent in both sexes. Serum testosterone level has a high correlation with sexual performance of rams during mating (Abdullah et al., 2002). A peak in estradiol is associated with behavioral estrus in the ewe. Because sex hormones such as testosterone and estradiol are modulated by the hypothalamo–pituitary axis, the male sexual behavior and female reproductive performance may be measurable (Fourie et al., 2002). Using of younger lambs may reduce production costs, accelerate benefits of genetic selection, and allow earlier progeny and libido testing. Benefits of advanced puberty in lambs may be accentuated in year-round breeding programs that can take advantage of development of early fertility. Nutrient preservation in silages is largely the result of fermentation by lactobacilli or other lactic acid producing bacteria. Several studies recorded improvement in nutrients digestibility with using microbial inoculates (El-Shinnawy, 2003; Abido, 2005; ElAshry et al., 2008; Abedo et al., 2013). Also, Alcˇ et al. (2010) found that microbial inoculants had a positive effect on grass silage characteristics in terms of lower pH and higher lactic acid concentration and establishment in the grass silage very well. Nutrition is a factor influencing the start of lamb’s puberty and has an important effect on sexual maturity breeding, age at slaughter and system of production which are closely related to the feeding variety (Fernando et al., 2011). The objective of the present study was to determine live body weight, age at puberty of two sex lambs, and fertility rate of Rahmani sheep fed microbial inoculated corn silage.

The study was conducted at the El-Serw Experimental Research Station belongs to Animal Production Research Institute, Agriculture Research Center, Ministry of Agriculture, Egypt. Ensiling procedures and silage quality Whole corn plants at doughy stage of maturity were chopped 1–1.5 cm length via chopping machine and ensiled in two heaps. The first heap was used as control forage, but the second heap was mixed with microbial inoculation (MID/1) for animal’s silage produced by National Research Center. The microbial inoculation contains a total of compatible and specialized lactic acid bacteria, a range of anaerobic bacteria and an analyst for the fiber which produce glucose crisis to speed fermentation. The microbial inoculation was prepared as follows: mixing package of 1 l to 100 l of water and leave for 2 h and sprayed on 50 tons silage and squeezed well. All heaps were covered by double-layer of linoleum plastic and straw bales to tighten coverage. Samples from two heaps were taken after 60 day for analysis of silage quality. Animals and feeding After weaning, Rahmani lambs (14 males and 16 females) of similar birth type were identified to compare between microbial inoculation corn silage (MICS) and corn silage (CS) on sexual characteristics and production of male and female lambs. The male and female lambs had average live body weight of 18.77 kg and 16.56 kg, respectively. The two sex lambs were randomly divided into four groups: the first two sex group lambs as control and the second two sex group lambs as trial. The first group of lambs (n = 7 males and 8 females) were received R1 ration which contained CFM + WS + CS. However, the second group of lambs (n = 7 males and 8 females) nourished R2 consisted of CFM + WS + MICS. The concentrate feed mixture (CFM) and wheat straw (WS) were offered as basal diet to all experimental lambs. The feed intake of male and female lambs was adjusted every 2 weeks depending on the animal body weight according to NRC (2007). All R1 and R2 diets were offered in two parts at 9 a.m. and 4 p.m. daily. Composite of feedstuff samples were analyzed according to the methods of the AOAC (1995). Two sex lambs were weighed at biweekly intervals and kept under similar environmental conditions in a semi-open shaded yard during the experimental period. The fresh water and blocks of salt were available all times of experiment. The compositions of diets are presented in Table 1. Body weight and body condition score of lambs Body weight was recorded biweekly until 48 weeks of age. Body condition scores were manually evaluated at puberty

Age at puberty and fertility of Rahmani sheep fed on biological inoculated corn silage Table 1

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Chemical composition, cell wall constituents and minerals content of basal feedstuffs.

Items component (%)

Chemical composition of experimental feeds a

OM CP CF EE NFE Ash NDF ADF Minerals contents Macro (%) Ca P Mg Na K Trace (ppm) Zn Fe Mn Cu b ME MJ/kg DM

CFM

WS

CS

MICS

93.30 15.24 14.91 3.42 59.73 6.70 45.85 15.26

83.19 3.42 36.51 1.81 41.45 16.81 73.51 51.33

91.53 8.57 27.58 3.11 52.27 8.47 41.25 24.65

90.72 10.86 26.76 3.35 49.75 9.28 38.61 22.53

0.87 0.98 0.44 1.57 0.67

0.22 0.07 0.13 0.15 1.28

0.25 0.23 0.16 0.02 1.06

0.42 0.38 0.23 0.08 1.65

24.00 58.00 74.00 4.11 12.02

11.14 113.24 28.12 3.15 8.60

21.82 73.74 14.85 6.81 9.76

31.69 83.84 22.91 9.56 10.65

CFM = concentrate feed mixture. WS = wheat straw. CS = corn silage. MICS = biological inoculated corn silage. a CFM consisted of: 25% undecorticated cottonseed meal, 39% yellow corn, 7% soybean meal, 20% wheat bran, 5% molasses, 2.5% limestone, 1.0% common salt, and 0.5% minerals mixture. b Metabolizable energy (ME) calculated according to MAFF (1976).

age of lambs by palpating the fullness of muscling and fat over and around the vertebrae in the loin area using a score system for 1–5 grades (1 being emaciated and 5 being obese).

of testis with calipers. Testes volume (cm3) was calculated according to the equation given by El-Zelaky et al. (2011): Testes volume ðcm3 Þ ¼ 0:0396  ðaverage testis lengthÞ  ðscrotal circumferenceÞ2 :

Puberty assay in female lambs Puberty was recorded when female lamb exhibited its first estrus behavior. At 20 weeks of age, teaser rams were introduced to the female lambs to detect the onset of the first estrus. Teaser ram was introduced two times daily with 12 h interval at 6 a.m. up to 6 p.m. of each group for 60 min. Female lambs being receptive for teaser and standing for mounting by the teaser were considered in estrus. The onset of first estrus was used as an indicator for the onset of puberty. Date of onset the first estrus were recorded for each female lamb and considered as an indicator for pubertal age. Puberty assay in male lambs Pubertal behavior was observed for all male lambs post-weaning till the noticing of puberty (first ejaculate with motile sperm). Libido observance for each male lamb was measured within 25 min using estrus female, considering the following criteria: first mounting without erection (stage I), first mounting within 1st penile protrusion (stage II), and puberty as age at first collected ejaculate containing motile sperm (stage III). Age, weight, scrotal circumference, and testes volume were determined at each stage of puberty. Scrotal circumference (SC) was evaluated at the time of semen collection using a flexible tape around the widest point of the testes (maximum circumference of the paired testes). The measurement of testis length was taken at the point of top and bottom dimensions

Progesterone and testosterone assays Blood samples were collected from the jugular vein weekly up to puberty age of male and female lambs. On the day of sampling, blood was taken at 8.0 a.m. into heparinized tubes (5 I.U heparin/tube). Plasma was harvested by centrifugation at 3500 rpm for 15 min within an hour of collection. Plasma testosterone samples were run in a single assay having a CV of 5.6%. Similarly, all progesterone samples were run in a single assay having a CV of 7.3%. Both hormones were analyzed using radioimmunoassay kits (Diagnostic Product Company, LOS Angeles, CA). Semen collection After puberty, semen samples were evaluated for volume (using graduated vials) and initial motility (ranging from 0% = total immobility to 100% = rapid wave motion). Evaluation of live spermatozoa, abnormal sperm percentage, and sperm cells concentration · 109 was performed later in the laboratory. Fertility test for ram and ewes Fertility test for ram was conducted with two rams aged P24 months without significant differences in semen

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characteristics: the 1st ram was fed R1 and the 2nd ram received R2 ration. Both R1 and R2 diets were offered before breeding season (8 weeks) and continued till the end of mating season. The ram fed R1 and ram supplied R2 mated 48 ewes (not feed neither R1 nor R2), which divided into two groups. One group mated by R1 ram and the other by R2 ram. Fertility test for ewes was carried out with two groups (n = 12/ group) as well as in production and reproduction characteristics. The 1st and the 2nd ewe groups were fed R1 and R2, respectively. The 1st and the 2nd ewe groups were mating by one mature and healthy ram (non-nourish of R1 or R2). The R1 and R2 rations were given before 4 weeks as flushing period to ewes and keep up to end of mating season. The pregnancy rate was diagnosed after mating when ewes passed two estrous cycles without return to heating.

improve body weight and reproductive performance. These results are in agreement with Lehloenya et al. (2008) who reported that yeast culture as a biological additive to buffalo’s rations improved nutrient digestion, body weight production, and composition diets. Also, Titi et al. (2008) showed that biological inoculant supplementation increased digestibility with enhancing effect on growth performance, feed intake, or feed conversion ratio of fattening lambs and kids. The physiological processes related to puberty in a number of species have provided evidence for the importance of dietary intake on sexual maturation. Koyuncu and Canbolat (2009) suggested that a minimum body weight was critical for first ovulation to occur in ewe lambs; moreover, lambs reared on a high plane of nutrition had increased uterine and pituitary weight and more marked thyroid development. Nkosi et al. (2010) concluded that inoculant treatments had positive effects on the fermentation of maize silage and improved the intake, apparent digestibility, and N retention of maize silage diets. Furthermore, Hafez et al. (2011) confirmed that lambs fed microbial inoculated additive to corm silage realized higher (P < 0.05) digestibility coefficients than feeding un-inoculated.

Statistical analysis All data were subjected to analysis of variance using general linear model (GLM) SAS (2009). Mean treatment differences were obtained by Duncan’s multiple range tests with a level of statistical significance of 5%. Pregnancy rate value was statistically tested using Chi-square test.

Progesterone and testosterone assay at puberty Blood progesterone

Results and discussion

Fig. 3 shows the influence of either R1 or R2 on progesterone (P4) concentration in female lambs. The most of the female lambs did not indicate any external signs of estrus, but showed periodically elevated P4 levels lower than 1.0 ng/ml during the observation period. In the present study, puberty in the R1 and R2 fed showed significant (P < 0.05) difference in their mean of P4 levels 1.53 and 1.89 ng/ml for the observation period at 38 weeks and 34 weeks, respectively. Generally, female lambs were considered to be pubertal upon sustained elevation in P4 concentration above 1.0 ng/ml over two consecutive blood collections. This observation is consistent with Milton et al. (1990) and Chagas da Silva et al. (2003) who reported that progesterone level >1.0 ng/ml is indicative of luteal function. Prepubertal P4 was produced in blood stream by luteal structure embedded within the ovary. Similar results were reported by Beradinelli et al. (1980) who indicated that two transient elevations of progesterone occurred prior to puberty in ewes and confirmed that the first and the second rises of progesterone were produced by luteal tissue in the ovary. On the other hand, Ramaley and Bartosik (1974) suggested that there is evidence that the adrenal gland produces progesterone before puberty. Regarding the addition of microbial inoculation to corn silage,

Live body weight

Live body weight (kg)

Live body weight (LBW/kg) of male and female lambs consumed R1 and R2 rations post-weaning at 12 weeks up to 48 weeks is illustrated in Figs. 1 and Fig. 2, respectively. Also, it is of interest to note that the values of LBW of two sex lambs with R2 tended to be higher (P < 0.05) than those of R1 at all measuring time. The results revealed that the average LBW of either rations R1 or R2 tended to be gradually increased with development animal’s ages. The changing in LBW of two sex lambs had fed R2 diets may be related to energy intake. Similar trend has been observed by Hosseini et al. (2008) who found that energy is the major dietary element that is responsible for the different utilizations of nutrients, thereby the productivity and body gain of an animal. Moreover, high levels of minerals were also shown to have a positive influence on ultimately lamb weights at weaning and puberty (El-Zelaky et al., 2011). On the other hand, application of some feeding techniques such as using some biological (yeast culture) or mineral mixtures as feed additives for corn silage may be help to 65 60 55 50 45 40 35 30 25 20 15 10 5 0

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Age (weeks) R1

Fig. 1

R2

Average live body weight of male lambs consumed R1 and R2 rations.

Age at puberty and fertility of Rahmani sheep fed on biological inoculated corn silage

167

Live body weight (kg)

50 45 40 35 30 25 20 15 10 5 0

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R1

Progesterone level (ng/ml).

Fig. 2

Average live body weight of female lambs consumed R1 and R2.

2.5 2 1.5 1 0.5 0 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39

Age (weeks) R1

Testosterone level (ng/ml).

Fig. 3

R2

Progesterone level (ng/ml) of female lambs consumed R1 and R2 rations.

4.5 4 3.5 3 2.5 2 1.5 1 0.5 0 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

Age (weeks) R1

Fig. 4

R2

Testoserone level (ng/ml) of male lambs consumed R1 and R2.

it caused an energy balance that played an important role to activate P4 secretion in blood stream that affects follicular growth and function. These findings are confirmed by Mohajer et al. (2010) who mentioned that energy had significant effect on blood FSH and progesterone concentration. Blood testosterone Plasma testosterone concentrations during the experimental period are shown in Fig. 4. The male lambs treated with R2 had higher (P < 0.05) average plasma testosterone concentration (2.20 ± 0.23 ng/ml) than lambs fed R1 (1.53 ± 0.34 ng/ml) through puberty period. The testosterone levels were low at early stages of sexual development in all tested groups and gradually increased with advanced age. The body weight and testicular size as affected by chronological age may be attributed to active testosterone secretion. The male lambs with bigger testes produced more testoster-

one levels than the lambs with smaller testes. Prepubertal testicular growth rates have been used to predict adult testicular size and spermatogenic function. Koyuncu et al. (2005) indicated that regression equations have revealed that testicular size was positively related to body weight and age in lambs. The positive correlations were found between prepubertal lamb hormone levels and subsequent either testes size or age. These previous results agreed with Elmaz et al. (2007) who concluded that testosterone concentration was 0.4 and 2.5 ng/ml when testes volume 17.3 and 211.9 cm3 with 100 and 200 days of age, respectively. The present trend of increase in testosterone concentration at all stages such as first mounting, first mounting with erection, and first ejaculation (puberty) was significantly (P < 0.05) better with R2 than R1 lambs. The present values of testosterone concentration in blood plasma in groups of R1 and R2 at puberty are within the range of 3.37 and 3.62 ng/ml, respectively. Kridli et al. (2006) suggested that ram lambs were considered to be

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pubertal based on elevated testosterone concentrations higher than 2.5 ng/m. Superiority of R2 lambs compared to R1 lambs in testosterone levels may be related to improve energy intake. This finding agreed with that reported by Scott et al. (2011) who found that the mechanism underlying this sexspecific effect of testosterone is may be due to sexual differentiation of the brain centers controlling energy expenditure. Puberty in female lambs Characteristics of puberty in lamb as affected by consumption of either R2 or R1 diets are explained in Table 2. The females fed R2 had better (P < 0.05) puberty parameters such as age at puberty, body condition score, and daily gain during puberty than the group received R1. These positive effects of feeding MICS may be mediated through high digestibility of nutrients diets and improve their ruminal fermentation and energy intake. Similarly, Resende et al. (2006) reported that energy deficiency delays puberty and decreases animal fertility, body weight gain, and other productive parameters. Data revealed that R1 and R2 have not significantly differed on average live body weight at puberty. However, average live body weight at puberty tended to be slightly increased with addition of biological inoculant. Chelikani et al. (2003) revealed that average daily gain and body weight together contributed to 96% of the variation in attaining puberty. Available minerals in R2 may activate metabolic hormones signals that may play an important role in determination of onset of puberty. Shirley et al. (2001) found that heavier ewes tended to produce more growth hormone (GH) which attained puberty earlier than lighter weight ewes. Wells et al. (2003) suggested that thyroxin (T4) may be an indicator of onset of puberty because T4 rises gradually from low concentrations just before onset of the breeding season to peak concentrations just before the transition to an estrus. EI-Saidy et al. (2008) suggested that ewe lambs growing at faster rates exhibited their first estrus and the most likely to conceive at a younger age than ewe lambs growing at slower rate. Furthermore, Ionel et al. (2012) claimed that the onset of puberty in hybrid merino ewe lambs born in autumn in the lower Danube area takes place at the age of 50–52 weeks, and in general, the onset of puberty takes place in most of the ewes at the age of 6–9 months, but also at 3–4 months in breeds that mature earlier or much later 18– 20 months.

Table 2

Puberty in male lambs The development in reproductive performance of the lambs prepubertal and up to puberty is presented in Table 3. Differences among tested groups were higher significantly (P < 0.05) in reproductive patterns of R2 lambs than R1 lambs. The mean stage of puberty ages of R2 and R1 lambs was 22 and 26 weeks at I stage, 26 and 30 weeks at II stage, and 32 and 36 weeks at III stage, respectively. The obtained range of puberty stages are in agreement with those of El-Badawy (2003) who reported similar pubertal age results. The lambs in R2 expressed first ejaculation (puberty) younger by 4 weeks than those in R1 lambs. These results are in agreement with the results by El-Ashry et al. (2000) who reported that Rahmani ram lambs reached puberty at age ranged between 36 weeks and 40 weeks. Preponderance puberty of male lambs fed R2 compared to R1 lambs related to major substances such as energy (Abdel-Baset (2009), protein (El-Zelaky et al., 2011) and minerals (Va´zquez-Armijo et al., 2011a). Semen collection at puberty Results in Table 4 presented significant (P < 0.05) differences among treatments as well as among months within each treatment in all seminal characteristics. Ram lambs fed R2 produced better semen quality (volume, initial motility, live spermatozoa, abnormal spermatozoa, and sperm cell concentration) than those in R1 group. The improvement of semen characteristics in R2 lambs was related to available maintenance nutrition requirements compared with R1 lambs. Nutrition appears to mediate its effect through increasing the frequency of pulses of LH and probably FSH (Hotzel et al., 2003). The hypothalamo–pituitary system has been one of the most studies by modern reproductive biologists. It has been found that reproductive axis does not seem to be closely linked with dietary intakes of amino acids or with circulating concentrations of glucose. However, the energetic components of the diet, particularly fatty acids, appear to play a key role in reproductive responses to changes in nutrition. Fatty acids can stimulate GnRH-dependent pathways that initiate changes in testicular function (Blache et al., 2002; Fernandez et al., 2004). Dietary energy is the most important factor which affects semen quality in farm animals. The deficiency of dietary energy causes delay of animal puberty and suppresses libido

Puberty parameters in ewe lambs consumed R1 and R2 rations.

Items

Experimental rations R1

Weaning weight (kg) Weight at puberty (kg) Age at puberty (weeks) Body condition score (1–5) Total gain at puberty (kg) Daily gain from birth to weaning (g/d) Daily gain from birth to puberty (g/d) Daily gain from weaning to puberty (g/d) Progesterone level at puberty (ng/ml) a,b

R2 a

15.64 ± 1.45 35.21 ± 2.43a 38.51 ± 11.05a 2.46 ± 0.25b 19.57 ± 1.24a 125.11 ± 4.11b 82.43 ± 4.23b 68.43 ± 1.45b 1.53 ± 0.11b

Means within the same row with different superscripts are significantly different at (P < 0.05).

16.48 ± 1.32a 38.88 ± 2.92a 34.12 ± 12.21b 3.07 ± 0.23a 22.40 ± 2.11a 134.00 ± 7.21a 99.88 ± 3.21a 87.84 ± 2.56a 1.89 ± 0.07a

Age at puberty and fertility of Rahmani sheep fed on biological inoculated corn silage Table 3

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Puberty parameters in male lambs consumed R1 and R2 rations.

Items

Experimental rations R1

R2

1st mounting without erection and ejaculation Body weight (kg) Age (weeks) Body condition score (1–5) Scrotal circumference (cm) Testes volume (cm3) Testosterone concentration (ng/ml)

34.93 ± 5.85a 26.83 ± 8.63a 2.52 ± 1.32b 12.42 ± 2.23 b 154.43 ± 6.78b 0.75 ± 0.11a

31.08 ± 6.42a 22.38 ± 7.32b 3.41 ± 1.13a 17.87 ± 3.35a 166.98 ± 8.81a 1.94 ± 0.22a

1st mounting with erection and without ejaculation Body weight (kg) Age (weeks) Body condition score (1–5) Scrotal circumference (cm) Testes volume (cm3) Testosterone concentration (ng/ml)

39.05 ± 6.45 30.75 ± 8.63a 2.71 ± 1.52b 17.32 ± 5.73b 201.32 ± 8.18b 2.25 ± 0.18a

36.93 ± 7.51 26.11 ± 8.12b 3.67 ± 1.61a 21.95 ± 6.75a 212.98 ± 10.85a 2.39 ± 0.15a

1st mounting with erection and with ejaculation Body weight (kg) Age (weeks) Body condition score (1–5) Scrotal circumference (cm) Testes volume (cm3) Testosterone concentration (ng/ml)

44.23 ± 6.45 a 36.72 ± 8.63b 2.83 ± 1.42b 23.42 ± 6.42a 343.11 ± 7.06b 2.81 ± 0.32a

47.84 ± 7.12 b 32.14 ± 7.32a 3.52 ± 1.33a 26.76 ± 7.73a 355.61 ± 9.15a 3.12 ± 1.03a

a,b

Means within the same row with different superscripts are significantly different at (P < 0.05).

Table 4

Semen characteristics at puberty for male lambs consumed R1 and R2 rations.

Items

Ejaculate volume (ml) Initial motility (%) Live sperm (%) Abnormal sperm (%) Sperm cell concentration (·109/ml) a,b

Experimental rations R1

R2

0.61 ± 0.10b 68.65 ± 2.32b 72.21 ± 2.12b 17.65 ± 3.25a 1.26 ± 0.23b

0.76 ± 0.21a 74.58 ± 3.12a 78.95 ± 2.32a 12.21 ± 2.25b 1.58 ± 0.55a

Means within the same row with different superscripts are significantly different at (P < 0.05).

and semen production (Fourie et al., 2004). Also, EI-Saidy et al. (2008) elaborated that the percentage of live sperm was changed significantly in high dietary energy level compared to low dietary energy level of lambs. Lambs are accepted to consume R2 higher than R1 that played a mark role in semen amelioration. This proposition is reinforced by Tufarelli et al. (2010) who concluded that dietary higher feed resulted in improved body weight gain, feed intake, sperm production, and semen quality in rams. As indicated by scrotal circumference (SC) and testicular size were affected by nutrition, with SC value being lower for R1 than improved diet in R2 during puberty. This result gives support to the hypothesis that testicular growth can be affected when animals are fed their maintenance requirement. Our result is in agreement with those obtained by Jibril et al. (2011) who reported that size of SC may play the largest role in semen parameters of Yankasa rams. Generally, the study has demonstrated that the spermatogenesis in male lambs is sensitive to increases in LBW of R2 lambs compared to R1 lambs. This effect has been related to an increase in testicular size because it is due to an

increase in the volume of seminiferous epithelium and in the diameter of seminiferous tubules. This result is consistent with the study of Bernardini et al. (2011) who found that the number of spermatozoa per ejaculate is related to testis volume and testis weight. Fertility test with rams and ewes The results of the present study showed that ram (Table 5) and ewes (Table 6) fed R2 had greater significantly (P < 0.05) mean fertility test and reproductive parameters than R1. Reproductive performance of livestock is determined by four factors: genetic merit, physical environment, nutrition, and management. Nutritional factors are perhaps the most crucial in terms of their direct effects on reproductive phenomenon and the potential to moderate the effects of other factors. Moreover, nutritional factors, more than others, readily lend themselves to manipulations to ensure positive outcomes (Smith and Akinbamijo, 2000). Thus, adequate nutrition could encourage mediocre biological types to reach their genetic

170 Table 5

E.I. Khalifa et al. Fertility test for ram consumed R1 and R2 rations.

Items

Experimental rations

No. of mating ewes No. of ewes conceived Pregnancy rate %a

R1

R2

24 17 70.83b

24 19 79.17a

a,b

Means within the same row with different superscripts are significantly different at (P < 0.05).

potential, alleviate the negative effects of a harsh physical environment, and minimize the effects of poor management techniques. These results are in agreement with those obtained by William and Charles (2003). Thus, negative energy balance may impair fertility by delaying first estrus, limiting the number of estrus cycles occurring before the preferred breeding period. This was in consistent with those reported by YoelZeron et al. (2002) who found that ewes which fed a diet contained energy increased number of follicles and oocytes found on the ovaries of ewes. As for average birth weight, it was higher (P < 0.05) in R2 than R1 ration. This was in consistent with the results of Toteda et al. (2004) who pointed that lambs born from ewes offered diets contained energy had higher (P < 0.05) birth weight than lambs born from ewes fed control diet. Bacterial inoculants have positive effects on volatile fatty acid (VFA) that had an indication of good fermentation and significantly live weight gain (Wrobel and Zastawny, 2004). Thus, VFA especially propionic type of fermentation is associated with an increase in the plasma levels of glucose and insulin, an increase in fat deposition, ameliorated protein, and an increase in the efficiency of metabolic energy retention, all of these factors contribute to the improved body performance (Raeth-Knight et al., 2007). Glucose modulates ovarian activity through effects at multiple levels through changes in circulating metabolic hormones (e.g. GH, insulin, insulin, and leptin) and acting to modulate the action of key reproductive hormones (e.g. gonadotrophins, steroids, and inhibins) at the

Table 6

target organ (Campbell et al., 2010). The MICS diet had greater minerals that may be required to support normal motility and involved in the regulation of sperm motility than CS diet. These results are supported by Watanabe et al. (2011) who found that Ca2+ concentration affected the swimming sperm, indicating proteins may be associated with regulation of flagellar waveform and Ca2+ impacts both kinase and phosphatase activities. Also, Rodriguez et al. (2012) concluded that Ca2+ importance of normal mitochondrial calcium cycle in the achievement of sperm capacitation and the maintenance of progressive motility in bovine spermatozoa. Furthermore, available zinc in R2 is essential for more than 300 enzymes, protein synthesis, reproductive system, proper hormonal metabolism, and deficiency reduced sexual performance (Falana and Oyeyipo, 2012). Moreover, Marzec-Wro´blewska et al. (2012) suggested that fermentation supplied diet with chemical elements known as necessary for capacitation and progress of the acrosome reaction. In general, Valsa et al. (2013) considering that the quality of semen was good in sperm count and excellent in motility probably due to available calcium and magnesium in diet. In connection with ewe’s fertility, minerals such as phosphorous (P), calcium (Ca), magnesium (Mg), manganese (Mn), copper (Cu), and zinc (Zn) are all involved in governing successful reproductive processes and had been shown to improve production parameters. These results are showed similar trended with Hefnawy and To´rtora-Pe´rez (2010) who reported that mineral has effects on every phase of the reproductive cycle. Also, Va´zquez-Armijo et al. (2011b) found that Zn plays a key role in maintaining the integrity of the epithelia of the female reproductive organs, which is necessary for embryo implantation and affect in any phase of the reproductive processes such as estrus, gestation, and lactation. Further, Tabrizi (2012) conformed that low Cu content in sheep rations causes embryo loss and inhibits embryo implantation and fetal death. Additionally, energy is playing an increasing important role in the fertility parameters. Nevertheless, energy has a significant impact on numerous reproductive functions including hormone production, folliculogenesis, fertilization, and early embryonic development in

Fertility test for ewes consumed R1 and R2 rations.

Items

Experimental rations R1

R2

No. of mating ewes No. of ewes conceived Pregnancy rate %A No. of ewes lambed Fertility as (%) from mated ewe lambsB Fertility as (%) from total ewe lambsC Ewes body weight at lambing (kg) Total No. of lambs born Average birth weight (kg) No. of ewe lambs birth single No. of ewe lambs birth twins Litter sizeD

12 10 83.33b 8 80.00b 66.67b 47.14 ± 8.17b 8 2.79 ± 0.89b 8 – 1.00

12 11 91.67a 10 90.91a 83.33a 52.87 ± 7.34a 13 3.88 ± 1.11a 7 3 1.30

a,b A B C D

Means within the same row with different superscripts are significantly different at (P < 0.05). Pregnancy rate = No. of ewes conceived‚ No. of ewes mating · 100. Fertility as (%) from mated ewe lambs = No. of ewes lambed ‚ No. of ewes conceived · 100. Fertility as (%) from total ewe lambs = No. of ewes lambed ‚ No. of ewes mated · 100. Litter size = Total No. of lambs born ‚ No. of ewes lambed.

Age at puberty and fertility of Rahmani sheep fed on biological inoculated corn silage female mammals (Azizi-Moghadam, 2012; Garcia-Garcia, 2012). On the other side, Senosy et al. (2013) stated that energy has a major role in controlling the oestrous cycle, determining oestrous behavior, ensuring oocyte competency, subsequent embryo survival rate, and determining both postovulation corpus luteum function and progesterone synthesis. Conclusion According to the results obtained in this study, it could be confirmed that microbial inoculation can be preserved corn silage and can improve its chemical composition and ruminant value that refluxed on productive and reproductive performance of growing male and female lambs. Furthermore, microbial inoculation provides a cheap energy and protein source for the ruminant animals which reduce the cost of feeding. References Abdel-Baset, N.S., 2009. Effect of different dietary energy levels on the performance and nutrient digestibility of lambs. Vet. World 2 (11), 418420. Abdullah, A.Y., Husein, M.Q., Kridli, R.T., 2002. Protocols for estrus synchronization in Awassi ewes under arid environmental conditions. Asian Austral. J. Anim. 15, 957–962. Abedo, A.A., Hafez, Y.H., Khalifa, E.I., Bahera, Mohamed, K., ElZolaky, O.A., 2013. Milk yield and composition of dairy Zaraibi goats fed microbial inoculated corn silage. Egypt. J. Sheep Goat Sci. 8 (1), : 141–151. Abido, A.M.M., 2005. Effect of Using Bacterial Inoculantes on Maize Silage Quality. M.Sc. Thesis. Faculty of Agriculture, Ain Shams University. Egypt. Alcˇ, D.J., Laukova´, A., Kisˇ idayova´, S., 2010. Effect of inoculants on fermentation parameters and chemical composition of grass and corn silages. Slovak J. Anim. Sci. 43 (3), 141–146. AOAC, 1995. Official Methods of Analysis, 16th ed. Association of Official Analytical Chemists, Washington, DC, USA. Azizi-Moghadam, A., 2012. Metabolism of energy substrates of in vitro and in vivo derived embryos from ewes synchronized and super ovulated with norgestomet and porcine follicle stimulating hormone. J. Anim. Sci. Biotechnol. 3, 3–7. Beradinelli, J.B., Dailey, R.A., Butcher, R.L., Inskeep, E.K., 1980. Source of circulating progesterone in prepubertal ewes. Biol. Reprod. 22, 233–236. Bernardini, A., Hozbor, F., Sanchez, E., Forne´s, M.W., Alberio, R.H., Cesari, A., 2011. Conserved ram seminal plasma proteins bind to the sperm membrane and repair cryopreservation damage. Theriogenology 76 (3), 436–447. Blache, D., Adam, C.L., Martin, G.B., 2002. The mature male sheep: a model to study the effects of nutrition on the reproductive axis. Reprod. Supl. 59, 219–233. Campbell, B.K., Kendall, N.R., Onions, V., Scaramuzzi, R.J., 2010. The effect of systemic and ovarian infusion of glucose, galactose and fructose on ovarian function in sheep. Reproduction 140, 721– 732. Chagas da Silva, J., Lopes da Costa, L., Cidadao, R., Robalo Silva, J., 2003. Plasma progesterone profiles, ovulation rate, donor embryo yield and recipient embryo survival in native Saloia sheep in the fall and spring breeding seasons. Theriogenology 60, 521–532. Chelikani, P.K., Ambrose, J.D., Kennelly, J.J., 2003. Effect of dietary enzyme and protein density on body composition, attainment of puberty and ovarian follicular dynamics of dairy heifers. Therio 60, 707. EI-Saidy, B.E.I., Gabr, A.A., El-Shinnawy, M.M., El-Badawy, M.M., 2008. Influence of diets supplemented with fish oil on productive

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