An on-farm trial of 90 days was conducted at Kushkal village, Palanpur taluka in Banaskantha district of Gujarat to study the effects of probiotics supplementation on nutrient utilization and feed conversion of lactating kankrej cows. Fourteen lactating Kankrej cows of uniform body weight, milk yield and with 2nd and/or 3rd lactation number in the initial stages of lactation were selected for the experiment to observe the effect of probiotic supplementation and were divided into two dietary treatments i) T1 (control: concentrate mixture + Green fodder + Dry fodder) and ii) T2, Probiotics supplementation (15 g/d/animal probiotics containing Saccharomyces cerevisiae; 1.5 x 108 cfu/g and bacteria, Lactobacillus sporogens; 5 x107cfu/ g + T1) were fed. The results revealed that supplementing probiotics to lactating Kankrej cows significantly improved intake of DM, CP and TDN while DCP intake, water intake and feed conversion efficiency of nutrients like DM, CP, DCP and TDN in relation to milk yield and FCM remained statistically similar as compared to control. The average DM intake of experimental cows during digestion trial in treatment groups T1 and T2 were 10.03±0.04 and 10.27±0.04 kg/d and when expressed as kg/100kg B.wt. it was 2.66±0.06 and 2.75±0.09 and in terms of g/kg W0.75 was 117.15±2.03 and 120.69±3.02. The treatment group T2 recorded significantly higher (Pd”0.01) DM intake. The average CP and TDN intake of T1 and T2 groups were 1012.03±1.53 and 1057.91±9.40 g/d and 6135.39±254.17 and 6919.64±262.35 g/d, respectively, differ (Pd”0.05) statistically but the average DCP intake was 576.44±35.88 and 665.75±39.63  g/d, respectively, remained statistically (Pe”0.05) similar. The average digestibility coefficient of OM, CP, CF and NFE in T1 and T2 were remain statistically (Pe”0.05) similar except DM (65.21±1.88 and 70.89±1.76) and EE (46.92±2.78 and 59.78±3.47). The feed conversion efficiency of experimental Kankrej cows in treatment groups T1 and T2 in terms of intake of DM (kg/kg milk yield), CP (g/kg FCM), DCP (g/kg milk yield) and TDN (kg/kg FCM yield) respectively, were statistically (Pe”0.05) similar.  

Keywords: DCP; Feed conversion efficiency; Kankrej cows; Nutrient utilization; Probiotics.