Effect of early and late weaning on the growth of female kids

Small Ruminant Research Small Ruminant Research

18 (1995) 33-38

Effect of early and late weaning on the growth of female kids J.M. Palma a, M.A. Galina a*b** “Centro Universitario de Investigacidn y Desarrollo Agropecuario, Universidad de Colima AP, 22 Colima. Colima, 28ooO Mexico bDepartamento de Ciencias Pecuarias, Facultad de Estudios Superiores de Cuautitldn, Universidad National Autdnoma de Mixico, Cuautitlin Izcalli, Edo de MLxico. Mexico Accepted

10 October 1994

Abstract

An attempt was made to develop a feeding system that would produce female kids able to start breeding early, at 7-8 months, with average body weight (B W) of 30 kg . A second objective was to measure dry matter intake (DMI) to calculate the cost of the rearing process. Two weaning ages were tested: one with an abrupt early weaning at 10 kg; the other with late partial weaning until BW reached 15 kg. The first group (48 goats) reached 25.9 & 2.9 kg in 120 days, with a daily weight gain of 98 k 35 g on average. These kids achieved 30 kg at 210 days and their reproductive weight at 9 months of age. Group 2 (28 animals) was first to reach the objective ( 180 days), and that time added to 60 days nursing gave a total of 8 months (30.3 + 2.9 kg BW), with a daily gain of 120 f 35 g on a diet of 26.5 kg extra milk during partial weaning. Total DMI of goats in Group 1 was 175 kg ( 103 kg alfalfa and 72 kg concentrate), while Group 2 DMI was 230 kg ( 135 kg forage and 95 kg supplement). The total cost per goat to achieve 30 kg was US$26.39 for early weaning and US$39.54 for late weaning, which showed a 33% higher cost for late weaning. Feeding systems represented between 67 and 86% of the total cost of rearing, but that would be recovered if the kids were sold for meat at local prices. It was concluded that faster growth could be obtained if milk was supplied for a longer period than the usual abrupt weaning at 10 kg. However, in both systems, animals could be available for breeding at 8-9 months of age, to kid at 13-14 months of age. Keywords: Kids; Rearing; Growth: Early weaning

1. Introduction

It has been shown previously that quick growth for early reproduction depends on nutrition and management, where feed represents about 75% of overall production costs (Morand-Fehr et al., 1982; Hadjipanayiotou et al., 1991b). Post-weaning growth of dairy goats has been related to age, level of nutrition, mother’s adult weight, size of litter, breed and season of birth, among other factors ( Morand-Fehr, 198 1; Galina and Silva, 1983). Kid feeding systems for post* Corresponding

author at: AP. 22, Colima, Colima, Mexico 28000.

0921~4488/95/$09.50 0 1995 Elsevier Science B.V. All rights reserved SSDIO921-4488(95)00681-8

weaning have been discussed by Hadjipanayiotou et al. (1991b) and Bas et al. (1991). Early reproduction can be achieved in young dairy goats when they reach 60% of their adult weight, which for dairy breeds is between 30 and 35 kg body weight (SW) (Morand-Fehr, 1981; Morand-Fehret al., 1982; Hadjipanayiotou et al., 1991b). To obtain that growth, kids have to average a daily weight gain (DWG) of over 120 g for the first 5 months, and thereafter slow down slightly to reach 30 kg in about 7-8 months. In some French observations, the average BW of 2-yearold Alpine dams was 58 kg while for males it was 95 kg (Morand-Fehr et al., 1982). Other studies reported

34

J.M. Palma, M.A. Galina /Small Ruminant Research I8 (1995) 33-38

post-weaning DWG between 142 and 156 g with a diet that was composed of alfalfa and concentrate ( 18% CP) given as pellets ad libitum (Hadjipanayiotou, 1987). In Mexico, research has shown DWG from 50 to 90 g in different management production systems, resulting in female goats between 22 and 26 kg in 7-8 months. However, the adult weights of the does were less than those of the French goats, with an average of 52 kg at 2 years old (Hernandez, 1978; Rodriguez, 1980; Mora et al., 1985; Ramirez, 1985). Voluntary intake has been extensively reviewed, and a “fill unit” system for predicting the voluntary dry matter intake (VDMI) of forage-based diets in ruminants has proved to be accurate in the field (Jarrige et al., 1986). We have tried the system on goats, with promising results (Galina et al., 1992, 1994). Feed intake, expressed in kg dry matter (DM), whether or not related to MW, is highly dependent on the growth stage and rate, and also on the nature of the feeds offered, particularly their energy content (MorandFehr et al., 1982). Previous studies have suggested that to rear a 30 kg female kid, 250 kg of feed is needed, composed of 150 kg good quality forage such as alfalfa hay and 100 kg concentrate of 16-18% CP, given after a nursing period in which the kids consumed from 60 to 80 kg of milk (Galina, 1987, 1992) Recently, some controversial figures for the protein and energy requirements for growth have been reported by Hadjipanayiotou et al. (1991a) and Sanz-Sampelayo et al. (1991). Energy requirements for maintenance have been suggested to be from 101 Kcal per kg w.” with an additional supplement of 7.25 Kcal metabolizable energy (ME) per g of weight gained (WG) , (NRC, 1981). However, variances from 100 to 120 Kcal ME per kg W”.75 and from 7 to 12 Kcal ME per g gain have been noted (INRA, 1988; Sanz-Sampelayo et al., 1991). Protein requirements for growing goats varied from 4.3 to 19.7 g DP per kg Wc.75 and 0.5 to 0.8 g CP per g gain (INRA, 1988; Hadjipanayiotou et al., 1991a). All these findings have shown the key role of nutrition and cost in rearing, so different approaches have been assessed to obtain an equilibrium between growth and economics (Retana, 1993). The objective of this work was to develop an economical rearing system that would balance DWG with cost and could produce animals ready for reproduction at around 7 or 8 months of

age. Early and late weaning systems, accompanied by high energy and protein diets, were tested to obtain early-breeding female kids.

2. Materials and methods Research was conducted on a private farm located in Cerro Prieto, Queretaro, Mexico, at 20”35’ north and lOO”18’ west. The altitude was 1950 m above sea level with a Bsl kw (w) (e) climate described as dry semiarid with scattered rain in the winter and 460 mm annual rainfall (Garcia, 1973). During the study period the outside temperature was 3.7”C minimum during the night and early morning, and reached 30.7”C maximum during the day. The average temperature was 17.3”C (SD f 0.3). The kids were closely confined during the night when the temperature decreased to 8 or 10°C inside the pen, and were allowed into the sun during the daytime. Straw bedding was provided and was changed every day. For the study, 70 young female kids, Saanen, Alpine or Toggenburg, were managed in full confinement. All animals were born in late November and were an average of 60 days old at the beginning of the observation period. The early-weaning group was composed of 42 female kids, with an average initial weight of 10.0 f 1.6 kg. They were given a diet of alfalfa hay and a commercial concentrate in a ratio of 60:40. The late-weaning group was composed of 28 female kids with an average weight of 9.4 f 0.9 kg. This group was fed as the early-weaning kids but with an additional 30 days of milk. During this period of milk feeding, solids (alfalfa hay and concentrate) were always available. Dry matter intake was determined using two systems: first by the “fill unit” as proposed by Jarrige et al. (1986), employed by INRA (1978, 1988), and modified for goats by our research group (Galina et al., 1992) ; second by weekly individual weighing of forage offered and refused. The diet was a mixture of 60% alfalfa hay and 40% commercial concentrate ( 18% CP and 3.1 Meal of ME). The amount offered was weighed and a 10% refusal was allowed. Forage leftovers were also weighed. Feed was offered twice per day in both weaning treatments and water was always available. At the beginning of the observation period, all kids were dewormed for external and internal parasites. Weekly

J.M. Palma, M.A. Galina /Small Ruminant Research 18 (1995) 33-38

test for average differences 1988).

forage samples were analyzed for CP, ether extract (EE) , crude fibre (CF) and total ash by AOAC ( 1984) procedures. Digestibility was calculated by the “in vitro” method of Tilley and Terry (1963). Fill units for every week were calculated for alfalfa as suggested by INRA ( 1978, 1988). The additive method for nutritional requirements as suggested by INRA ( 1978,1988) was employed, with energy and protein amounts as suggested by Sanz-Sampelayo et al. ( 1991) and Hadjipanayiotou et al. ( 1991b), respectively. Total requirements for maintenance and growth were then correlated with the ones calculated by the fill-unit method or the total feed intake weighed individually, adding the total protein and energy contents provided by the forage analysis. Variables taken into consideration were DWG, time needed to attain 30 kg, DMI after weekly adjustments, daily forage offered and refused, and feed cost calculated every 7 days. The study began on 28 January 1993 and ended when animals of both groups reached 30 kg. Statistical analysis of the data was made using the tTable I Daily body weight gain for early- and late-weaned Weaning

35

for small samples

(CSS,

3. Results The results are summarised in Table 1. Late-weaning kids were the first to reach 30 kg with a DWG of 137 g over 180 days. Post-weaning time plus nursing gave a total of 8 months. Early-weaning animals reached 26 Fig. 1 kg in the same period, with a DWG of 98 g. shows the average accumulated weight gains for both groups. Gains were similar in the first 3 months and differed significantly thereafter, resulting in the lateweaning kids being faster to reach the 30 kg goal. Fig. 2 compares growth between the two experimental groups (in g month- i) after weaning. The increments show that growth was similar in both groups, but smaller in Group 1 (early weaning) where there was a minimum and maximum DWG of 135 and 139 g, respectively, compared with 167 and 171 g, respec-

kids (mean f sd)

Initial weight

Final weight

DWG over 180 days

(kg)

(kg)

(9)

Animals > 30 kg in each group (%)

Early

lO.O+ 1.6

25.9 f 2.9 ’

9s*35

Late

9.4 f 0.9

30.3 k2.9 b

137f35b

a,b Means with different superscript DWG, daily weight gain.

a

are different at P < 0.05.

28

24 Live weight (kg) 20

8

! 0

1

2 Monthly

3

4

5

live weight

Fig. 1. Weight gains for early and late weaning systems.

6

1 7

(22142)

52

(21/28)

77

J.M. Palma, M.A. Galina /Small Ruminant Research 18 (1995) 33-38

36

g/d

0.15

‘i

0

6

7

8

Monthly observations

Fig. 2. Daily weight gains in early and late weaning systems.

tively, for late weaning. In both groups a depressive effect of weaning was shown, but the shock was less in Group 2. However, after 8 months both groups achieved a similar weight when not pregnant. Table 2 summarises the total DMI of alfalfa and concentrate separately. The average consumption of alfalfa was 572 g for the early-weaning group and 739 g for the late-weaning group. Concentrate consumption was 400 g for Group 1 and 528 g for Group 2. Lateweaned kids consumed 26.5 kg more milk before total weaning was achieved. The total DMI of goats in Group 1 was 175 kg DM (103 kg alfalfa and 72 kg concentrate), while the total DMI of goats in Group 2 was 230 kg ( 135 kg of forage and 95 of supplement). The early-weaned group total feed cost was US$26.40 per animal. In the late-weaned kids the total feed cost was US$40.00peranimal, of which US$34.50 was forage and US$5.00 the additional milk, i.e. 33% higher than the first group (US$13.10). However, goats in the second group were 4 kg heavier. In both cases, feeding accounted for 67-87% of the total price of female kids.

4. Discussion Other studies have presented a new system to predict voluntary intake of forage-based diets in ruminants that have proved to be effective in cows (Garcia-Trujillo and Caceres, 1985; Jarrige et al., 1986) and goats (Galina et al., 1992). Previous work has discussed the various factors that determine DMI during growth, i.e. age, sex, litter size,

mother’s size and feed quantity, quality, nature and feeding system (Morand-Fehr, 198 1; Galina and Silva, 1983; Hadjipanayiotou et al., 1991a). The present study showed that less DMI was needed for growth in young goats than the amount previously recommended (Hadjipanayiotou et al., 1991a; Galina, 1992). Highquality forages such as alfalfa hay and concentrates based on barley and soybean have been shown to cause a significant rise in the cost of the diet, and the DWG in the present study was smaller than the French results. There are two possible reasons for this. First, the CP in the diet was of lower quality because the concentrates did not contain soybean, and second, there is a lower genetic potential for growth (to reach 58kg) for Mexican goats than for European goats. Finally, kids were housed in open pens with partial protection during the day, so some energy had to be spent maintaining their body heat. In other studies, animals were fully confined and kept from environmental hazards. Other studies demonstrated that growth diminishes after weaning, particularly if the supply of milk is abruptly terminated (Morand-Fehr, 198 1). In the present study, the post-weaning effect was noted in both study groups even, in late-weaned kids. However, growth compensation for early abrupt weaning did not appear (Morand-Fehr et al., 1982). Continuous growth of late-weaned animals pointed to the positive effects of milk on growth. Kid growth gains observed in the present study were 98 and 137 g day-‘, which were lower than the European results which reported gains up to 142 and 156 g day-‘. The differences could be explained by the amount and quality of concentrate supplied (up to 85%

J.M. Palma, M.A. Galina /Small Ruminant Research 18 (1995) 33-38 Table 2 Total DMI of alfalfa and concentrate Alfalfa hay (kg) Early Late

103 133

37

per animal over 180 days Commercial concentrate

Additional milk

(kg)

(kg)

72 95

26.5

of the diet), and probably also by differences in adult doe weight (Morand-Fehr et al., 1982). Normal rearing management in Mexico abruptly weans at 10 kg BW. The present results on growth in both weaning systems were superior when compared with previous observations with normal weaning performed in similar semi-confinement, and with those reported by Herndndez (1978), Mora et al. (1985), Ramirez ( 1985) and Rodriguez ( 1980). Nevertheless, female kids, weighing 28 to 30 kg, were ready for early breeding when nutritional requirements were met and minimum conditions for growth were provided. When daily DMI was evaluated, female kids in the present study appeared to consume less than previously reported (Morand-Fehr et al., 1982). Our results ranged from 0.7 to 0.9 kg per animal day- ‘, while other work showed DMI from 0.9 to 1.3 kg animal-’ day-’ for animals of the same size. Difficulties in calculating DMI, variances in alfalfa hay fibre, and differences in the amount of concentrate offered could explain these results. However, the kids seemed to have a larger ruminal capacity than previously reported. The results of the present study were similar to others reported Mexico (Hernandez, 1978; Rodriguez, 1980; Mora et al., 1985; Ramirez, 1985). The price of dairy goat meat during the study was US$l.51 per kg BW. The cost with Group 1 (early weaned) showed a profit of US$12.97 animal-’ and with Group 2 (late weaning) of US$5.90. Dollar gain was smaller but physiological development was greater in the second group. Previous studies demonstrated the feasibility of using better feeds to obtain growth under economical conditions (Retana, 1993). It is clear that growth was smaller than reported elsewhere. Nutritional management with alfalfa hay and commercial concentrates was feasible in cost and for early reproduction. Late-weaned kids performed significantly better, reaching the goal 1 month before the early-weaned kids, which is a strong recommendation

Total DMI (kg)

Rate of conversion (kg)

175 230

11.0 11.0

for the investment. Total DMI needed appeared to be less than that calculated in previous Mexican research (Galina, 1992). Therefore, nutritional and management systems to obtain early reproduction in kids are recommended to use high-quality forages.

Acknowledgements The authors thank Janet Hummel for technical assistance, and DGAPA, UNAM, grants IN300192/ IN300391, and CONACYT, grant 3 108-N, for their support of the study.

References AOAC, 1984. Official Methods for Analysis, 14th edn. Association of Official Agricultural Chemists, Washington, DC, 1141 pp. Bas, P., Morand-Fehr, P. and Schmidely, P., 1991. Weaning: A critical period for young kids. In: P.Morand-Fehr (Editor), Goat Nutrition. Pudoc, Wageningen, 46, pp. 271-283. CSS, 1988. Complete Statistical System. Version 8640. Statsoft, Tulsa, OK, 614 pp. Galina, M., 1987. Kids milk intake during lactation. Proc. IVth Int. Conf. Goats. EMBRAPA Brasilia, Brazil. Vol. 2, pp. 1455 Galina, M., 1992. Caprinotecnia. (Dairy Goat Management.) Agrosystem Editing, Colima, Mexico, 2 17 pp. Galina, M. and Silva, E., 1983. Efecto de1 peso, edad y dpoca de1 parto en la presentation de la pubertad en la cabra. (Effect of body weight, age and season of parturition in the presentation of puberty in goats.) IX Congreso National de Buiatrfa, Puebla, Mexico, pp. 342-346. Galina, M., Palma, J.M., Morales, R. and Hummel, J. 1992. Consumo voluntario aparente en caprinos con el metodo de unidades empanzonantes. (Voluntary dry matter intake of goats with the till unit system approach.) Av. Inv. Agropecuaria, Mexico, 14: 92-108. Galina, M., Palma, J.M., Morales, R., Aguilar, A. and Hummel. J., 1994. Voluntary dry matter intake by dairy goats grazing on rangeland or on agricultural by-products in Mexico. Small Rum. Res., 15: 127-137. Garcia, E., 1973. Modificaciones al Sistema de Clasiticaci6n Climatica de K&en. (Modifications to the Climate Classification

38

J.M. Palma, h4.A. Galina/Small Ruminant Research 18 (1995) 33-38

of Kopen.) Instituto de Geografia, Universidad National Autbnoma de Mexico, 155 pp. Garcia-Trujillo, R. and Caceres, O., 1985. Nuevos metodos para expresarel valor nutritivo de 10sforrajes. Consumo. (New methods to express nutritive value of forages. Intake.) Pastos y Forrajes, Cuba Tomo, 8: 449-470. Hadjipanayiotou, M., 1987. Intensive feeding systems for goats in the Near East. Proc. IVth Int. Conf. Goats. EMBRAPA Brasilia, Brazil, Vol. 2, pp. 1109-l 141. Hadjipanayiotou, M., Brun-Bellut, J. andLindberg, J.A., 1991a.Protein nutrition and requirements of growing goats, In: P. MorandFehr (Editor), Goat Nutrition. Pudoc, Wageningen, 46, pp. 8293. Hadjipanayiotou, M., Economides, S., Monnd-Fehr, P., Landau, S. and Havrevoll, 0.. 1991b. Post-weaning feeding of young goats. In: P. Morand-Fehr (Editor), Goat Nutrition. Pudoc, Wageningen, 46, pp. 284-29 1. Hemandez, P., 1978. Efectos de la nutricibn sobre la presentaci6n de la pubertad en las cabras. (Effect of nutrition in the presentation of puberty in goats.) Thesis, Fact&ad de Medicina Veterinaria y Zootecnia, Universidad National Autdnoma de Mexico, Mexico, 35 pp. [NRA, 1978. Alimentation des Ruminants. (Ruminant Nutrition.) Institute Nationale de la Recherche Agronomique, Paris, 621 pp. INRA, 1988. Alimentation des bovins, ovins et caprins. (Nutrition of Bovine, Ovine and Caprine Animals.) Institute Nationale de la Recherche Agronomique, Paris, 47 1 pp. Jarrige, R., Demarquilly, J., Dulphy, J.P., Hoden, A., Robelin, J., Beranger. C., Geay, Y., Journet, M., Malterre, C., Micol, D. and Petit, M., 1986. The INRA “fill unit” system for predicting the voluntary intake of forage-based diets in ruminants: A Review. J. Anim. Sci., 63: 1737-1758.

Mora, M., Sosa, M. and Riquelme, E., 1985. La paja de cacahuate coma suplemento alimenticio de1ganado caprino en la mgi6n de Chiautla, Puebla. (Use of peanut straw as a nutritional supplement for goats in Chiautla, Puebla.) Colegio de Posgraduados, Texcoco, Mexico, 35 pp. Morand-Fehr, P., 1981. Growth. In: C. Gall (Editor), Goat Production. Academic Press, London, pp. 253-283. Morand-Fehr, P., Hervieu, J., Bas, P. and Sauvant, D., 1982.Feeding of young goats. IIIrd Int. Conf. Goat Production and Disease. International Goat Association, Tucson, AZ, pp. 253-283. NRC, 1981. Nutrient Requirements of Goats. National Academic Press, Washington, DC, 91 pp. Ramfrez, A., 1985. Recria de cabritas de reemplazo bajo desaffo alimenticio en un sistema de producci6n intensivo. (Rearing of kids under a nutritional challenge on an intensive production system.) Thesis, Facultad de Estudios Superiores Cuautitlrln, Universidad National Aut6noma de Mexico, Mexico, 5 1 pp. Retana, J., 1993. AlimentaciQ de la recria de un hato caprino con base en una dieta integral en el tr6pico seco mexicano. (Feeding of kids in a goat herd based on a composite diet in the Mexican dry tropics.) Thesis. Facultad de Estudios Superiores Cuautitlan Universidad National Aut6noma de Mexico, Mexico, 36 pp. Rodriguez, M., 1980. Manejo de la reproduccidn y nutricidn de un sistema de crfa de cabras lecheras. (Management of reproduction and nutrition of goats for rearing.) Thesis, Facuhad de Medicina Veterinaria y Zoot&cnia, Universidd National Autdnoma de Mexico, Mexico, 66 pp. Sanz-Sampelayo, M.R., Bas, P. and Schmidely, P., 1991. Energy nutrition in growing goats . In: P. Morand-Fehr (Editor), Goat Nutrition. Pudoc, Wageningen, 46, pp. 94-103. . Tilley, J.A. and Terry, R.A., 1963. A two-stage technique for the in vitro digestion of forage crops. J. Br. Grassl. Sot., 18: 104-l 11.