Studies on goats: I. Effect of plane of nutrition on the reproductive performance of does

Abstract

SummaryThe project involved two breeds of Indian goats – Barbari and Jamunapari, three levels of energy and three levels of protein, making a total of 18 treatments. There being no specific recommendations for goats, the high, medium and low levels of energy (T.D.N.) and protein (D.C.P.) represented 125, 100 and 75% of Morrison's standard for sheep, respectively. A total of 97 Barbari and 87 Jamunapari does were allocated to the nine ration treatments and were bred within the breed naturally. The rations comprised a concentrate mixture (linseed cake and/or barley grain), dry roughage (gram bhusa), greens, mineral and trace-element mixtures and common salt. The effect of nutrition on reproductive performance, as revealed by the five and four kiddings completed in the Barbari and Jamunapari was as follows:While the first kiddings did not indicate a sizeable effect, the subsequent ones showed a significant effect of nutrition. Almost all the does in the low-energy groups, irrespective of the protein levels, did not kid for the last kidding under reference.The maximum percentage of twins was noted in high-energy-cum-high-protein (47·5%)and high-energy-cum-medium-protein (45·3%) groups of Barbari and Jamunapari respectively. The average twin-birth percentages, irrespective of nutrition, were 14·8, 37·3, 38·0 and 40·2 in Barbari and 9·0, 20·5 and 23·0 in Jamunapari respectively. Triplets, although rare, occurred within the Barbari but only one case occurred within the Jamunapari.On average Barbari and Jamunapari had 2·0 and 1·5 kids per doe per year in the high-energy-cum-medium-protein group compared with 1·0 and 0·4 in the low-energy ones, respectively. Furthermore, high- and medium-energy groups had shorter intervals between kiddings compared with the low-energy ones.