Effect of Milk Allowance on Concentrate Intake, Ruminal Environment, and Ruminal Development in Milk-Fed Holstein Calves

Abstract

The aim of the present experiment was to test the hypothesis that a barley-based concentrate would induce an acidic ruminal environment in young calves and that increased milk allowance would alleviate this condition. Eight Holstein calves ruminally cannulated at d 7 +/- 1 of age were used to study the effect of variation in barley-based starter concentrate intake induced by 4 different milk allowances (3.10, 4.84, 6.60, and 8.34 kg of milk replacer/d; 123 g of dry matter/kg of milk) on the ruminal environment, blood variables, and fore-stomach development from wk 2 to 5 of age. Twelve ruminal fluid samples were collected during a weekly 24-h sampling in 4 consecutive weeks. Blood samples were collected by venipuncture between 1200 and 1300 h on ruminal sampling days. Rumen papillae development and visceral organ mass were recorded at slaughter. A linear treatment x week effect was observed for concentrate intake, with the calves fed the lowest milk allowance having the fastest increase in concentrate intake whereby these calves reached the same ME intake in wk 5 compared with calves with the highest milk allowance. Effects on ruminal variables were dominated by week of sampling, with minor differences among treatments. Ruminal pH was below 5.5 for 5 to 13 h/d and all calves with concentrate intake above 20 g of dry matter/d were observed to have a daily ruminal pH minimum at pH 5.5 or lower. The ruminal concentration of total volatile fatty acids (VFA) increased from 71 to 133 +/- 9 mmol/L in wk 2 to 5 and was characterized by a relatively high molar proportion of propionate, increasing from 34 to 40 mol/100 mol of VFA in wk 2 to 5. In addition, the presence of ethanol and propanol as well as numerous VFA esters points to a ruminal environment with a relatively high hydrogen pressure. Plasma glucose and insulin responded to the highest milk allowance in wk 2 to 4. Plasma VFA and ketone bodies increased with the lowest milk allowance in wk 4 to 5. At slaughter, empty wet weights of the rumen + reticulum and omasum as well as mass of digesta in these compartments were found to decrease linearly and perirenal fat was found to increase linearly with milk allowance, indicating that the milk allowance changed the body composition of the calves. Lengths of ruminal papillae in the atrium and ventral ruminal sac were not affected by treatment. We concluded that the ruminal environment of young calves fed a barley-based starter concentrate was characterized by a low ruminal pH and high VFA concentration regardless of the milk allowance.

Influence of weaning regimen on intake, growth characteristics and plasma blood metabolites in male buffalo calves

“…Furthermore, despite a lower milk intake, EW calves showed similar growth performance to those weaned later (weeks 10 and 12). In one study, calves were fed 3.10, 4.84, 6.60, 8.34 kg/day of milk replacer with their weight gain being similar across all treatments (Kristensen et al, 2007). Milk consumption was higher during the first 6 weeks while consumption of CS was very low for the same period.…”

Effect of rearing system on pre-weaning growth, rumen development and its influence on post-weaning performance of lambs

“…Our findings do not agree, since digestive tract weight was greater for artificially than for naturally reared lambs. However, feeding frequency or meal size could moderate gastrointestinal development (Kristensen et al 2007), which could explain the differences between naturally and artificially reared lambs as average meal size would be expected to be greater for the latter. Omasum capacity of ewe reared lambs was higher than other groups (P=0.01) probably because more intake of milk.…”

Efeito da adição de butirato de sódio, propionato de cálcio ou monensina sódica no concentrado inicial sobre parâmetros ruminais e de desenvolvimento do rúmen de bezerros leiteiros

“…Outros autores observaram tendência de aumento nas concentrações de AGCC com o avanço da idade de bezerros em aleitamento (Greenwood et al, 1997;Beharka et al, 1998;Kristensen et al, 2007). Coverdale et al (2004) encontraram valores crescentes nas concentrações totais de AGCC ruminais em bezerros alimentados com dietas contendo diferentes formas físicas e níveis de inclusão de forragem.…”