Impact of graded levels of coated calcium butyrate on growth performance and serological indices during pre-weaning stage in Holstein calves.

The study aimed to analyze the impact of calcium butyrate supplementation in calf starter on growth performance indices associated with early rumen development to decrease the volume of milk or milk replacer feeding and enhance early starter intake in Holstein calves. For this purpose, twelve Holstein calves were randomly assigned into three treatments (n = 4/treatment); a control without coated calcium butyrate, T1, and T2 treatments supplemented with coated calcium butyrate 3 g and 6 g per day/head, respectively. Body weight was measured at days 7, 14, 21, 28, 35, 42, 49, and 56 of the trial, and the average daily weight gain and feed conversion ratio were determined. Blood samples were collected at 14, 28, 42, and 56 days of trial for serological parameters. Gut morphometry was performed at the end of trial at slaughtering by collecting duodenal samples. Furthermore, the meat was also evaluated for its quality parameters including pH and tenderness after slaughtering. The results indicated that the feed intake, average daily weight gain, feed conversion ratio, and gut morphometric parameters involving villus height and crypts depth of calves were improved in coated calcium butyrate-supplemented groups. Furthermore, the supplementation of calf starter with coated calcium butyrate significantly enhanced serum concentrations of glucose and total protein. Besides, Beta hydroxy butyrate (BHBA) levels of blood were also found to be elevated in both treatment groups. However, it was revealed that coated calcium butyrate supplementation had no significant effect on meat quality parameters. In conclusion, the supplementation of calf starter with coated calcium butyrate could improve calf performance.