Influence of dietary concentrate to forage ratio on the development of rumen mucosa in calves

Abstract

Effects of structural and non-structural carbohydrates on the development of rumen fermentation and ruminal mucosa in calves were examined during the weaning period. Barley/soybean meal (SBM) group was fed a concentrate starting from 2 weeks of age, whereas alfalfa group received a mixture of concentrate and alfalfa hay in which the proportion of the latter was gradually increased from 20% to 70% between weeks 2 and 9 of age. The total volatile fatty acid concentration in rumen fluid of calves increased with age, but at 9 weeks there were no significant differences between the two diets (barley/SBM group 153 mmol/l, alfalfa group 150 mmol/l). Rumen papillae at 9 weeks of age, as compared to 6 weeks of age, were longer and fewer in number per square centimetre mucosa, with larger cut surface. This resulted in a higher surface of papillae per square centimetre mucosa at 9 weeks (barley/SBM group 286 mm2/cm2, alfalfa group 245 mm2/cm2) than at 6 weeks of age (barley/SBM group 217 mm2/cm2, alfalfa group 198 mm2/cm2). At 9 weeks of age, the pH (barley/SBM 5.0, alfalfa 5.7), the acetate to propionate ratio (barley/SBM 2.2, alfalfa 3.2) as well as the length of the papillae in the ventral ruminal sac (barley/SBM 1.96 mm, alfalfa 2.37 mm) were increased in the alfalfa group when compared to the barley/SBM group (P < 0.1). In the former group, the proportion of butyrate revealed significantly increased values at 4 and 6 weeks of age. In animals of the barley/SBM group at 9 weeks of age, characteristic protrusions with proliferated thick epithelium occurred on the papillae and increased the surface for absorption. On the epithelium (Stratum corneum) desquamating cells with parakeratosis could be observed. In the alfalfa group the papillae of the ventral ruminal sac were longer, without protrusions. The morphotypes of the adhering rumen microflora differed between the groups. It can be concluded that feeding greater amounts of non-structural carbohydrates increases the surface for absorption of the rumen epithelium in calves. The absence of hyperkeratosis and rumenitis in the barley/SBM group indicated that there is no reason to limit high starch diets in the early weaning period of calves.

Determining optimum age of Holstein dairy calves when adding chopped alfalfa hay to meal starter diets based on measures of growth and performance

“…There were no significant differences between AH groups and CON calves at weeks 4 and 6 that may indicate that buffering of the rumen by AH may have become apparent after week 6; however, with increasing age, mean ruminal pH was greater at weeks 8 and 10 (P < 0.05 for both) for the calves fed AH diets than the calves fed CON diet. The observation of a greater ruminal pH by AH calves compared with CON calves is in agreement with the findings of other studies (Khan et al, 2011 (textured starter); Suarez et al, 2006 (pelleted diet); Zitnan et al, 1998 (with hay particle size of 2 to 4 cm)) showing an increase in ruminal pH when forage was added to the diet.…”

Influence of the diet on the morphology of ruminal and intestinal mucosa and on intestinal carbohydrase levels in cattle

“…It is known from literature that concentrate-rich diets cause an increased VFA (mainly propionic and butyric acid) production thus stimulating the metabolism of the rumen epithelium, the structural development and resorptive activity of the latter. (Kauffold et al, 1975;Hofmann and Schnorr, 1982;Jesse et al, 1995;Lane and Jesse, 1997;Zitnan et al, 1998). We could not observe any significant differences in the level of rumen fermentation since the animals had been killed 16 hours after the last feeding, however, the resorption surface of rumen papillae per cm 2 of mucosa was stated to be increased in the intensively reared group of animals which received higher amounts of the concentrate.…”

“…In animals fed low and high energy diets rumen mucosa revealed progressive reduction and intensive proliferation, respectively (Dirksen et al, 1985). Intensity of rumen fermentation increases with the increasing intake of concentrate and simultaneously the occurring volatile fa�y acids promote the structural development of the rumen epithelium (Kauffold et al, 1977;Hofmann and Schnorr, 1982;Zitnan et al, 1998).So far, insufficient or no investigations at all have been carried out into the effects of the diet upon the development of small intestinal mucosa.According to Tivey and Smith (1989), changes in the development of enterocytes and in the structure of villi determine the digestive and absorptive capacity of the small intestine. Kreikemeier et al (1990) studied the activity of carbohydrate digesting enzymes in Holstein and Longhorn bulls and observed it to be influenced by the type of diet and the level of feed intake.…”

“…In animals fed low and high energy diets rumen mucosa revealed progressive reduction and intensive proliferation, respectively (Dirksen et al, 1985). Intensity of rumen fermentation increases with the increasing intake of concentrate and simultaneously the occurring volatile fa�y acids promote the structural development of the rumen epithelium (Kauffold et al, 1977;Hofmann and Schnorr, 1982;Zitnan et al, 1998).…”

Study on the characteristics of gastrointestinal tract and rumen ecology of Formosan Reeves'

“…Ruminal papillae of a captive one were in filiform, however, the papillae were tongueshaped in wild muntjac rumen. Reticulum and omasum shape were similar to domestic ruminant, but the reticulum laminae were shallower than that in cattle or goat (Zitnan et al 1998;Lane et al 2000). The abomasum mucosal laminae of captive muntjac were conspicuous than a wild one, suggesting higher development of abomasums in captive muntjacs.…”