Performance of Crossbred Heifers Supplemented with Linseed Oil, Either Alone or in Combination with Myristic Acid

Abstract

In order to assess the impact of supplementing linseed oil (LO) and myristic acid (MA) on intake, digestibility and growth, fifteen Karan-Fries heifers (6–12 months of age and 120.15 ± 17.5 kg average body weight) were assigned randomly into three groups of five animals each. Group T1 served as control, fed with hand-mixed basal total mixed ration (TMR) containing concentrate mixture, wheat straw and green berseem (Trifolium alexandrinum) in proportion of 40, 40 and 20 %, respectively. In addition to basal TMR, animals in group T2 were supplemented with 2 % LO and group T3 with 1 % LO + 1 % MA for 120 days. Results revealed that, supplementation of fat sources in both the treatment groups (T2 and T3) did not exhibit any effect on intake of dry matter and crude protein in comparison with group T1. Digestibility coefficients of nutrients did not differ due to treatments, except that of EE, which was greater (P < 0.05) in groups T2 and T3 as compared with control. Furthermore, average daily gain and feed conversion ratio were not influenced by dietary treatments. Additionally, predicted methane emission was decreased up to 20.3 and 18.3 % in groups T2 and T3, respectively than that of group T1. Based on these findings, it was concluded that supplementing either 2 % LO or 1 % LO + 1 % MA may not be a viable nutritional strategy for achieving faster growth response in tropical crossbred dairy heifers at field level.