Effect of Functional Nutrient Supplements on Milk Production Performance and Hormonal Profile in Crossbred (Holstein-Fresian X) Cows Fed on Finger Millet Straw (Eluicine Coracana) Based Rations.

Abstract

Three functional nutrient supplements (Sup I, Sup II and Sup III) were prepared with 65% of locally available  different 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, PS, MGM and cottonseed cake CSC (70:15:15) in Supplement 3. The effective protein and fat degradability of different supplements were estimated in 3 crossbred fistulated steers.  A lactation trial of four months duration was conducted to study the effect of feeding functional nutrient supplements on milk production performance and hormonal profile of crossbred cows under field condition. Twenty-eight crossbred cows were randomly divided into four comparable groups (control and experimental) of seven each based on lactation number, milk yield and stage of lactation. The cows in control group (G-I) were fed finger millet straw (FMS) with supplements such as groundnut meal (GNC) and wheat bran(WB) as practiced by the farmers. Animals in experimental groups (G-II, G-III, and G-IV) were fed finger millet straw (FMS) with GNC, wheat bran and supplements 1 (Sup I), Sup II and Sup III, respectively @ 200g /day/animal by replacing the double the quantity of GNC in the experimental groups. Recorded milk yield (Twice a day) daily. Blood was collected and separated for plasma to determine hormonal status by radio immune assay (RIA). Microbial protein synthesis was estimated by analysing urinary purine derivatives. Total DM, OM, CP and TDN intakes recorded among experimental animals were not significantly different (P>0.05%).     The 4% fat–corrected milk (FCM) recorded was comparable among groups G-II, G-III, and G-IV, but higher (P<0.05) than G-I. Further, the milk composition in terms of fat, total solids and SNF showed a significant (P<0.05) improvement in experimental groups over the control group on FMS based diets.  The results showed the trend of 16, 12 and 9 % increase in FCM yield in animals of G-II, G-III and G-III, fed with limiting nutrient supplements Sup I, Sup II and Sup III, respectively when compared to G-I animals. Plasma hormonal profiles of growth hormone (GH), prolactin (PRL), insulin like growth factor1 (IGF1), estradiol-17β (E2β), progesterone (P4)_, triiodothyronine (T3) and thyroxine hormone (T4) were positively correlated with (r=0.69, P<0.05) milk yield in cows fed with functional nutrient supplements compared to controls. The microbial protein synthesis and nitrogen capture efficiency (NCE) was comparable among the experimental groups (G-II, G-III, and G-IV) but higher than the control group (G-I). The results indicated that, feeding of functional nutrient supplements, reduced CP intake by 8 to 12%, increased FCM yield from 9 to 16% without compromising the microbial protein synthesis, reduced feed cost by Rs 4 to 9 and increased overall income of the farmers by Rs 24 to 38 /animal /day in medium yielding cows fed on FMS based diets. Therefore, the functional nutrient supplements developed in the present experiment will be useful for precise feeding of protein, reducing the protein intake without compromising the productivity and microbial protein synthesis, thereby reducing the nitrogen excretion in to the environment.