Aims: A study was made to evaluate the effect of feeding different doses of probiotics on the milk yield and its composition of crossbred cows. Settings and Design: Twenty lactating crossbred cows were taken for the experiment and were randomly divided into four groups of five cows each. T0 (control group) cows were not fed with probiotics. T1, T2 and T3 (treatment groups) cows were fed with 10 gm, 15 gm and 20 gm probiotics per day. Methods and Material: Cows were fed basal diet along with production ration. Milk sample collected weekly and corrected for 4% FCM. Milk, fat % and SNF were analyzed by using milk analyzer. Statistical analysis used: In the present study, mean as a measure of central tendency and the standard error as a measure of random error were employed for the statistical analysis. The student ‘t’ test (P= 0.05) was used to know the significant variation between two groups. Results: Significant (Pd”0.05) differences were observed in milk yield of cows fed multi-stain probiotics as compared to the control. The average milk production (4% FCM) was highest in 20gm probiotics supplemented cows is 7.89±0.21, followed by 7.05±0.19 and 6.52±0.07 in cows supplemented with 15gm and 10gm probiotics respectively, as compared to the control animals (5.73±0.06). In T0,T1, T2 and T3 group cows the increase in fat percentage was observed to be 4.24+0.03, 4.45+0.02, 4.52+0.09 and 4.78+0.08 respectively during the trial period where as mean SNF percentage of T0, T1, T2 and T3 increased to 8.01+0.14, 8.07+0.04, 8.23+0.08 and 8.75+0.08 percent respectively. Conclusions: It can be concluded that use of multi-stain probiotics is cost effective and increased the milk production by 29.13 % in case of 20gm probiotics supplementation followed by 15gm (17.70%) and 10gm supplementation (8.31%), respectively, in lactating crossbred cows. After supplementation of probiotics, mean fat percentage increase of T1, T2 and T3 increased to 2.06, 5.36 and 10.65 percent respectively were as mean SNF percentage increase of T1, T2 and T3 increased to 0.75, 2.24 and 7.89 percent respectively. The net profit was estimated as Rs. 83.14, 85.43, 86.84and 93.15 per cow per day respectively in T0, T1, T2 and T3 groups and calculated cost-benefit ratio was 1: 1.42, 1: 1.47, 1: 1.53 and 1: 1.60 in T0, T1, T2 and T3 respectively.

Keywords: Probiotics Milk Yield Milk Composition Saccharomyces Cerevisiae Lactobacillus Acidophilus Lactobacillus Sporogenes Bacillus Subtilis and Bacillus Licheniformis.