Effects of early rumen development and solid feed composition on growth performance and abomasal health in veal calves

Abstract

The experiment was designed to study the importance of early rumen development and of the composition of solid feed intake on growth performance and abomasal health in milk-fed veal calves. One hundred and six Holstein-Friesian male calves were included in the experiment, and studied during 2 successive 12-wk periods (period 1 and period 2). In a 2 × 2 factorial arrangement, effects of partially replacing milk replacer by solid feed during period 1 and partially replacing dry matter (DM) intake from maize silage and barley straw by concentrate during period 2 were tested. Solid feed during period 1 consisted of maize silage, barley straw, and concentrate (25:25:50 on a DM basis). Solid feed during period 2 consisted of maize silage and barley straw (50:50 ratio on DM basis) for the nonconcentrate groups, and maize silage, barley straw and concentrates (25:25:50 on a DM basis) for the concentrate groups. At the end of period 1 (n=16) and at the end of period 2 (n=90), parameters of animal performance, rumen development, rumen fermentation, ruminal drinking, and abomasal damage were examined. Partially replacing milk replacer by solid feed during period 1 resulted in early rumen development (ERD) at the end of period 1, characterized by increased rumen weight, and an increased epithelial and absorptive surface area. Both ERD and partially replacing roughage by concentrates in period 2 increased the rumen development score at the end of period 2. Although ERD calves consumed more solid feed and less milk replacer during period 1 and 2 than non-ERD calves, carcass weight gains at 25 wk were identical, and utilization of the solid feed provided appeared similar to that of milk replacer. Partially replacing roughage by concentrates in period 2 increased dressing percentage and warm carcass weight. Plaque formation at the rumen mucosa was unaffected by ERD or partially replacing roughage by concentrates and generally low in all calves. The prevalence of large scars in the abomasum in ERD calves was decreased compared with non-ERD calves. This may indicate that ERD provided protection against abomasal lesions. In conclusion, early compared with late rumen development improves feed utilization and may be beneficial for abomasal health.

Estimation of milk leakage into the rumen of milk-fed calves through an indirect and repeatable method

“…These values were lower than those previously reported for veal calves that received large amounts of solid feed (from 13% to 25% of intake; Suárez et al, 2007;Berends et al, 2012). In our study, calves receiving Co were slaughtered more than 2 h after feeding allowing liquid to leave the rumen.…”

“…Nevertheless, the relationship between measured AMVs and predicted AMV2 indicates that the use of ultrasonography and mathematical modeling of kinetics of AMV gives a reliable estimate of AMV to calculate RMV. Using this technique, RMV averaged 16 (from 0% to 33%) and 21% (from 0% to 39%) of intake for bucket-fed calves in Experiments 2 and 3, respectively, which was in the lower range of values previously reported (more than 25%; Suárez et al, 2007;Berends et al, 2012).…”

“…In veal calves that received large amounts of milk, individual values may account for more than 25% of intake in subclinical cases (Suárez et al, 2007;Berends et al, 2012), which induces reduced growth performances and ruminal and metabolic acidosis in clinical cases (Gentile et al, 2004;Herrli-Gygi et al, 2006). Identification of clinical ruminal drinkers can be achieved through the occurrence of reduced appetite and clay-like feces (Breukink et al, 1988) but the latter indicators do not give any information regarding the amount of milk that enters the rumen.…”

“…This can be achieved by providing a soluble indigestible marker with the last feeding before slaughter, and then measuring marker recovery in the calf's rumen at slaughter (Suárez et al, 2007;Berends et al, 2012). This direct measurement requires quantitative collection of rumen contents, and does not allow repeated measurements on the same animal.…”

Utilization of roughages and concentrates relative to that of milk replacer increases strongly with age in veal calves

“…Milk-fed calves provided with concentrate feed as the only SF source had signs of parakeratosis and so-called plaque formation (i.e., patches of focal mucosa inflammation with coalescing and adhering papillae covered by SF particles, hair, and cell debris), which may inhibit rumen development and nutrient uptake (Suárez et al, 2006(Suárez et al, , 2007. Early rumen development is thought to increase utilization of SF in veal calves, especially toward the end of the fattening period (Berends et al, 2012b). However, the provision of SF to veal calves may increase the prevalence of abomasal lesions (Welchman and Baust, 1987;Mattiello et al, 2002;Brscic et al, 2011) and concentrate provision has been associated with ruminal drinking; that is, leakage of MR into the rumen (Berends et al, 2012b).…”