Effects of soybean milk replacer on growth, meat quality, rumen and gonad development of goats

• We studied the effects of milk replacer on growth and rumen development in goats.
• Kids fed soymilk had a non-significantly higher growth rate to 4 months old.
• Faster rumen development and lower dressing percentage was observed in kids fed milk replacer.
• Fifty percent of whole milk can be replaced by soymilk without altering the performance of kids.

The present study was aimed to determine the effect of soymilk as milk replacer on growth, carcass characteristics, rumen development, ovarian morphology and testicular development in kids. Twenty four Black Bengal kids were randomly allocated to three groups each containing 5 females and 3 males. One group was reared on 100 % whole milk, the second on 75% whole milk + 25% soymilk, and the third on 50% whole milk + 50% soymilk. Blood samples were collected to determine red and white blood cell counts, haemoglobin and packed cell volume. At 4 months of age the kids were sacrificed to examine carcass characteristics and to collect ovaries, testes and rumen samples for histological examination. Growth of kids in terms of live weight gain and pre-slaughter body measurements did not show any significant change due to feeding milk replacers. Kids fed whole milk were lighter at slaughter (4.93 ± 1.13 kg; mean ± SD) than those fed 25% (5.40 ± 0.62 kg) or 50% (5.34 ± 0.93 kg; NS) soymilk. Carcass weight, dressing percentage and chemical composition (DM, OM, EE and ash) of meat did not differ significantly. Histological examination revealed that the percentage of different types of ovarian follicles did not differ significantly among the treatment groups. The number of seminiferous tubules was significantly higher in milk replacer fed kids (25% soymilk 81.7 ± 3.78; 50% soymilk 86.7 ± 3.51) than whole milk fed control (71.7 ± 3.05) although the diameters did not differ significantly. In conclusion, whole milk could be replaced by soymilk up to 50% without significant effects on growth, carcass characteristics and rumen and gonad development.