Moderate Coconut Oil Supplement Ameliorates Growth Performance and Ruminal Fermentation in Hainan Black Goat Kids

The study investigated amelioration effects of coconut oil (CO) on growth performance, nutrient digestibility, ruminal fermentation, and blood metabolites in Hainan Black goat kids. Twenty-four Hainan Black goat kids (10 days of age) were assigned randomly to four treatments for 90 days, including pre-weaning (10–70 d of age) and post-weaning (70-100 d of age) days. The treatment regimens were control (CON), low CO (LCO), medium CO (MCO), and high CO (HCO) with 0, 4, 6, 8 g CO per goat per day, respectively. During the pre-weaning period, the average daily gain (ADG) linearly and quadratically increased (P < 0.05), whereas the average daily feed intake (ADFI) linearly decreased, and the feed conversion ratio (FCR) also decreased linearly and quadratically by increasing CO supplementation (P < 0.05). During the post-weaning period, increasing CO supplementation linearly and quadratically increased the BW at 100 days and ADG (P < 0.05), but quadratically decreased the ADFI and FCR (P < 0.05). The digestibility of ether extract (EE) linearly and quadratically increased with increasing CO supplementation (P < 0.05). Supplementation of CO linearly increased ruminal pH (P < 0.05), but linearly decreased (P < 0.05) ammonia-N, total VFAs, molar proportions of acetate, ruminal microbial enzyme activity of carboxymethyl-cellulase, cellobiase, xylanase, pectinase and α-amylase, and number of total protozoa, the abundance of Ruminococcus albus, Ruminococcus flavefaciens, Fibrobacter succinogenes, Butyrivibrio fibrisolvens, Prevotella ruminicola, and Ruminobacter amylophilus. The estimated methane emission decreased linearly and quadratically with increasing CO addition (P < 0.05). The serum concentration of triglycerides (TG), non-esterified fatty acids (NEFA) and growth hormone (GH) linearly (P < 0.05) increased by raising the CO supplementation. The present results indicate that CO supplementation at 6 g/day per goats is optimum due to improved growth performance and decreased estimated methane emission. Supplementation CO up to 8 g/day depressed growth and feed conversion due to its suppression of growth performance, rumen protozoa, cellulolytic bacteria and microbial enzyme activity, and reduced ADF and ADF digestibility.

Effects of fibrolytic enzymes and isobutyrate on ruminal fermentation, microbial enzyme activity and cellulolytic bacteria in pre- and post-weaning dairy calves

The objective of the present study was to evaluate the effects of fibrolytic enzymes (FE, containing 160 units of cellulase and 4000 units of xylanase) or isobutyrate (IB) supplementation on ruminal fermentation, microbial enzyme activity and cellulolytic bacteria in dairy calves. Forty-eight Holstein bull calves of 15 days of age and of 44.9 ± 0.28 kg of BW were randomly assigned to four groups in a 2 × 2 factorial arrangement. Two levels of FE (0 g (FE–) or 1.83 g per calf per day (FE+)) and IB (0 g (IB–) or 6 g per calf per day (IB+)) were added. Calves were weaned at 60-day-old and four calves were selected from each treatment at random and slaughtered at 45 and 90 days of age. There was no IB × FE interaction effect. Ruminal pH decreased with IB or FE supplementation for post-weaned calves, whereas concentrations of total volatile fatty acids and acetate increased with IB or FE supplementation for pre- and post-weaned calves. Acetate to propionate ratio increased with IB supplementation, but was unaffected by FE supplementation. Ammonia-N concentration decreased with IB or FE supplementation for pre- and post-weaned calves. For post-weaned calves, activities of CMCase increased with IB or FE supplementation, and activities of cellobiase, xylanase, pectinase, β-amylase and protease increased with IB supplementation. Populations of B. fibrisolvens and F. succinogenes for pre- and post-weaned calves and R. flavefaciens for post-weaned calves increased with IB or FE supplementation. It is suggested that ruminal fermentation and growth performance of calves was improved with IB and FE supplementation, and the combination of IB and FE has the potential to stimulate the growth of pre- and post-weaned dairy calves.