Rumen development in the calf

Abstract

1. Thirty Ayrshire bull calves were used in an experiment to study the effects of diets containing different proportions of concentrates to hay on rumen development at 12 weeks of age. In addition, six milk-fed calves were slaughtered at 3 weeks of age for comparison. 2. Restriction of the maximum daily allowance of concentrates to the lower levels was accompanied by an increase in the voluntary intake of hay, but the performance of calves from 3 to 12 weeks of age was significantly better in calves given the high-concentrate diets. 3. The weight of contents of the reticulo-rumen increased from 0.7 kg at 3 weeks of age in the milk-fed calf to 7.7 kg and 10.9 kg at 12 weeks in calves given the high-concentrate and high-roughage diets respectively. Between 68 and 79% of the total contents of the alimentary tract was contained in the reticulo-rumen of the ruminant calf. The weight of contents of the omasum was significantly greater in calves given 1.36 kg concentrates/day than in those given either 0.45 or 2.27 kg concentrates/day. Equations were developed from the results by which the weight of contents of the various parts of the alimentary tract, and hence empty body weight in the live animal, can be determined from a knowledge of the live weight and daily consumption of concentrates and hay, 4. Volume displacement of the reticulo-rumen tended to increase with increase in the proportion of hay in the diet. The volume displacement of the omasum increased in response to concentrate intake up to a maximum of 1.36 kg/day and thereafter declined, but the nature of the diet had no significant effect on the volume displacement of the abomasum. 5. Calves given the high-concentrate diets had a significantly greater weight of reticulo-rumen tissue at 12 weeks than those given the high-roughage diets. 6. Whereas the thickness of the muscular wall of the rumen did not differ significantly between treatments, there was an increase in the length and density of papillas, particularly in the anterior dorsal and ventral sacs of the rumen, as the intake of concentrates was increased. The results show the marked relationship between the performance of the animal and an advanced stage of development of the rumen papillas.

The effect of tributyrin supplementation to milk replacer on plasma glucagon‐like peptide 2 concentrations in pre‐weaning calves

“…Blood BHBA is a measure of rumen epithelial metabolic activity, and it indicates the conversion of ruminal butyrate to circulating BHBA when it passes the rumen wall (Lane, Baldwin, & Jesse, 2000). In addition, ruminal fermentation of calf starter increases ruminal concentration of volatile fatty acids (VFA), especially of propionate and butyrate (Stobo, Roy, & Gaston, 1966;Warner, Flatt, & Loosli, 1956). In the present study, a time effect was observed for serum BHBA concentration (p < 0.01; Figure 3b), and regardless of dietary treatment, BHBA increased from 5 weeks after birth, similar to the fluctuation of starter DMI.…”

Review: Utilization of yeast of Saccharomyces cerevisiae origin in artificially raised calves

“…This development depends on the establishment of ruminal flora, initiation of feed consumption, absorption processes and absorption mechanisms [82]. The VFAs especially butyrate are important in triggering rumen papillae growth [83] which provide the surface area for absorption of nutrients. Recently researchers have demonstrated the importance of introducing starter in calves at an early age.…”

Protein synthesis and growth in the gastrointestinal tract of the young preruminant lamb

“…The majority of liquid feed bypasses the reticulo-rumen by means of the oesophageal groove, and goes directly through the omasum to the abomasum (Church, 1969). The rumen mucosa exhibits only small and undeveloped papillae in milk-fed young ruminants (Warner & Flatt, 1965;Stobo et al 1966;Church, 1969). Therefore, a rather low estimate of FSR could be expected in the reticulo-rumen (Table 3).…”