Effect of bypass protein supplementation on nutrient utilization, milk production and its composition in crossbred cows on paddy straw based ration

An on-farm trial was conducted for a period of 90d on 14 crossbred lactating cows to study the effect of bypass protein supplementation on a paddy straw ration on nutrient utilization, milk production and reproduction performances. The crossbred cows were divided into two groups of seven in each on parity and daily milk yield basis. The experimental cows of both the groups were fed paddy straw, mixed grasses and concentrate mixture as per NRC (2001). The concentrate mixture of group 1 animals contained 25 parts of untreated groundnut cake (GNC) whereas that of group 2 contained 25 parts of formaldehyde treated GNC. The animals were maintained by the farmers in their sheds and fed individually as per the advice. The DM, DCP and TDN intake (kg/100 kg BW) were 2.91±0.02, 0.270±0.014 and 1.68±0.06 in group 1, and 2.98±0.02, 0.282±0.003 and 1.74±0.01 in group 2, respectively, which were statistically similar (P>0.05). The digestibility of DM and EE was significantly (P<0.05) higher in cows of group 2 than those of group 1. The digestibility of all other nutrients and cell wall fractions was similar in both the groups. The average milk yield (l/d) was significantly higher (P<0.01) in group 2 (9.84±0.01) compared to group 1 (8.72±0.01). The weekly average milk fat, milk protein, SNF and total solids percentages were 4.35±0.06 and 5.48±0.09; 3.33±0.01 and 3.44±0.02; 9.44±0.19 and 9.96±0.12; and 14.03±0.24 and 15.62±0.16 in groups 1 and 2, respectively, which were statistically (P<0.05) different. The group 2 cows earned Rs. 12.75 more profit per cow per day than group 1, accruing overall excess profit of Rs. 1147.50 in 90 days, indicating a clear advantage of bypass protein supplementation. The average post-partum oestrus period (d), average days of experimental feeding up to the first oestrus (d), services per conception (no) were 49.71±7.01 and 39.29±4.89; 120.00±0.69 and 109.28±0.61; and 1.8±0.02 and 1.14±0.14 in the groups 1 and 2, respectively. Seven cows in group 2 compared to 5 cows in group 1 were found pregnant registering a conception rate of 100% in the former. It is concluded that supplementation of formaldehyde treated GNC in place of untreated GNC in the concentrate mixture of crossbred cows on paddy straw based ration improved the production and reproduction performance economically.