Source of Carbohydrates from Different Grains on Rumen Microbial Protein and Milk Production in Native Dairy Cows

Abstract

Objective of the study was to evaluate effect of carbohydrates from maize, sorghum and oats grains on rumen microbial protein (MBP), milk yield and milk composition in dairy cows. Total soluble sugars (TSS) present in grain were 3 to 4% which were non-reducing sugars. Soya meal contained 5% TSS. Deoni breeds of zebu cows were fed ad libitum finger millet straw (Elusine coracana) as basal roughage. Sixteen cows were randomly divided in 4 × 4 Latin square design and supplemented with concentrate (CS) consisted of soya meal without any grain as control (CG) and maize (T1), sorghum (T2) or oats (T3) as grain source of energy. Although CS intake in CG, T1, T2 and T3 was 0.71, 1.17, 1.39 and 1.55 kg/d, respectively (P<0.01), no significant difference observed in total dry matter intake. Among 3 grains, MBP was lesser on maize and higher on sorghum. MBP production on oats and sorghum was statistically comparable. Sorghum was used more efficiently than oats grain. MBP flow to duodenum was 124 g/d in CG and only 9% lesser than T1 while, 51% and 42% lesser than T2 and T3 which was due to difference in CS intake. Efficiency of MBP, gN/MJ ME intake, was 3.34 in T2 compared to 2.53, 2.5 and 1.92, respectively in T1, T3 and CG (P<0.05). Repeated measure analysis indicated no significant difference within fortnights and among groups for 4% FCM yield and milk composition. Milk fat in CG was only 3.80% while it was more than 4% in TGs (P<0.05). In conclusion, addition of sorghum grain in CS had significant impact on rumen MBP and milk fat %. MBP production was more efficient on sorghum grain. Oats grain was statistically comparable to sorghum and had more impact on milk yield than milk composition. Milk yield and milk SNF constituents were affected without grain source in CS.