Metabolic and immune status of pre-weaning crossbred calves reared on different dietary regimes in Kerala

Abstract

Seventy two new born crossbred calves were selected and grouped in three dietary treatments-C, T1 and T2. Calves in the group T1 were fed ad libitum milk twice daily for one hour along with calf starter and green fodder. The T2 group were fed on the dietary protocol as T1 but was fed calf starter supplemented with essential oils. The dietary treatment of control group (C) was as per the Package of Practices Recommendations, KVASU. Blood samples were collected from the calves at the time of birth, second day and monthly intervals for up to three months for biochemical analysis. The plasma glucose concentrations of calves in dietary treatments C, T1 and T2 after one month were 5.69±0.166, 6.26±0.174 and 6.15±0.166 mM respectively. The glucose levels of calves in dietary treatments of C, T1 and T2 at three months were 4.22±0.062, 4.50±0.061 and 4.33±0.063, respectively and differed significantly (p<0.01) between C and T1. The serum concentration of Betahydroxy butyric acid (BHBA) for dietary treatments C, T1 and T2 increased with age and reached 0.418±0.025, 0.403±0.026 and 0.410±0.025 mM respectively and did not differ significantly between treatments. Significantly higher (P<0.05) serum cholesterol concentration of 2.82±0.090 and 2.86 ± 0.086 mM were recorded in calves in T1 and T2, respectively. Serum concentration of triglycerides, total protein and albumin were similar in all treatment groups. Lower BUN values of 8.96±0.64 and 8.89±0.64 mM were seen in T1 and T2, respectively while C group had serum BUN concentration of 10.33±0.63 mM. Increased levels of serum BHBA indicated rumen development where there is a shift in the precursor of energy from glucose to volatile fatty acids. Ad libitum colostrum feeding resulted in significantly higher (P<0.001) level of IgG from the second day improving the immune status of new-born calves.