An on-farm lactation trial of 4 months duration was conducted to study the effect of feeding strategic limiting nutrient supplements on milk production performance and hormonal profile of crossbred cows under field condition. Crossbred cows (36) were equally divided into 6 groups (control and experimental) based on lactation number, milk yield and stage of lactation. Strategic nutrient supplements (1, 2, 3, 4 and 5) were prepared with 65% of locally available bypass rich protein/amino acid supplements and 30% of the bypass fat and 5% of area specific mineral mixture (ASMM), respectively in all the supplements. Protected soybean extraction (0.9% formaldehyde treated; PS) was added as a source of bypass rich protein/amino acid supplement in supplement 1, PS and maize gluten meal (MGM) (60:40) in supplement 2, cottonseed cake (CSC) and MGM (60:40) in supplement 3, PS, MGM and CSC (70:15:15) in supplement 4 and PS, MGM and CSC (40:40:20) in supplement 5. The cows in control group were fed local mixed grass with supplements such as groundnut cake (GNC) and wheat bran as practiced by the farmers Animals in experimental groups (G 1, 2, 3, 4 and 5) were fed local mixed grass with GNC, wheat bran and supplements 1, 2, 3, 4 and 5, respectively @ 200g/day/animal by replacing the double the quantity of GNC in the experimental groups. There was an increase of 16, 14, 9, 10 and 2 % in 4% fat-corrected milk (FCM) yield in animals fed with limiting nutrient supplements 1, 2, 3, 4 and 5, respectively when compared to control. Plasma hormonal profiles of growth hormone, insulin like growth factor 1, estradiol-17 beta, progesterone, triiodothyronine and thyroxine hormone were positively correlated (r=0.69; P < 0.05) with milk yield in cows fed with strategic nutrient supplements (SNS). The study showed that feeding of supplements 1 and 2 in experimental groups-1 and 2 significantly (P < 0.05) increased FCM yield and reduced the feed cost in medium yielding cows on local mixed grass based diets and increased the overall income of the farmers.
