The provision of solid feeds to veal calves: II. Behavior, physiology, and abomasal damage1

Abstract

The aim of this study was to evaluate the effects of the addition of two roughage sources (wheat straw and beet pulp) to the milk replacer diet of veal calves, in order to reduce stress and improve animal welfare. We allocated 138 Polish Friesian male calves to three different feeding plans: a milk replacer diet (Control), 250 g/d of wheat straw in addition to the milk replacer, or 250 g/d of dried beet pulp in addition to the milk replacer. Within each feeding treatment, 16 calves were individually housed and 30 were kept in group pens (five calves/pen). Several behavioral, physiological, and health welfare indicators were monitored throughout the fattening period, which lasted for 160 d. Abnormal oral behavior around the meals was higher in Control calves (P< 0.01), while its lowest level was observed in straw-fed calves. At the beginning of the trial, chewing was higher in calves receiving solid feeds (P < 0.001), but the difference from the Control gradually decreased and disappeared at wk 13 for calves fed beet pulp and at wk 17 for those fed wheat straw. At the end of the fattening period, no differences among treatments were found in the frequency of chewing. Regardless of the diet, self-grooming decreased with age and no relationship was observed between this behavior and the presence of rumen hairballs. Cross-sucking was performed with low frequencies (from 4.70% at wk 2 to 1.05% at wk 23 around the meals, and even lower far from the meals) and was not affected by the provision of roughage. The time in contact with the bucket during the whole day was higher in Controls, whereas calves fed wheat straw maintained a lower level of this activity until the end of the trial (P < 0.01). The calves fed wheat straw spent more time in contact with the feed trough (P < 0.001) than those fed beet pulp and Control calves. No differences were found in cortisol curves due to the feeding treatment. In calves fed beet pulp, most hematological measures statistically differed from the other treatments, possibly in response to the higher iron intake and(or) to the higher hemoconcentration, probably due to the administration of beet pulp as dried feed. The incidence of abomasal ulcers and erosions was increased by the provision of the solid feeds, particularly by a structured fiber source such as straw. A roughage source able to satisfy calves' behavioral needs and to improve digestive processes without damaging the digestive apparatus still has to be identified.

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

“…The surface of abomasal damage increased with SF intake for an R:C ratio of 20:80 (P < 0.05), but not for 50:50 (interaction SF intake × R:C ratio: P = 0.11). Other studies showed that provision of SF to milk-fed calves increased the prevalence of abomasal damage, including pyloric ulcers, when compared with calves fed MR only (Breukink et al, 1991;Mattiello et al, 2002;Brscic et al, 2011). Solid feed particles may exert mechanically abrasive effects on the abomasal mucosa, which may be sensitized due to provision of large volumes of MR.…”

“…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). Recently, it has been shown that urea recycling contributes to nitrogen retention in milk-fed calves provided with a low-protein SF (Berends et al, 2012a) but this contribution decreases with increasing protein content in the SF (H. Berends, unpublished data).…”

The role of solid feed amount and composition and of milk replacer supply in veal calf welfare

“…Veal calves develop abnormal oral behaviors such as excessive oral manipulation of the pen and abnormal rolling of the tongue, that is, tongue playing (Leruste et al, 2014), most likely due to an inadequate provision of solid feed (SF) and, in particular, insufficient structure in the SF (Mattiello et al, 2002;Webb et al, 2013;Leruste et al, 2014). It has been suggested that little structure limits natural rumination, which in turn leads to frustration and stress in the calves and ultimately to the development of abnormal oral behaviors (Mattiello et al, 2002;Webb et al, 2013;Webb, 2014).…”

“…Veal calves develop abnormal oral behaviors such as excessive oral manipulation of the pen and abnormal rolling of the tongue, that is, tongue playing (Leruste et al, 2014), most likely due to an inadequate provision of solid feed (SF) and, in particular, insufficient structure in the SF (Mattiello et al, 2002;Webb et al, 2013;Leruste et al, 2014). It has been suggested that little structure limits natural rumination, which in turn leads to frustration and stress in the calves and ultimately to the development of abnormal oral behaviors (Mattiello et al, 2002;Webb et al, 2013;Webb, 2014). Increased rumination can occur through increasing the provision of SF (Webb et al, 2012(Webb et al, , 2013, increasing the proportion of roughage or the presence of longer particles in the SF (Balch, 1971;Mertens, 1997;Kahyani et al, 2013), or providing coarser roughage sources (Mattiello et al, 2002;Webb et al, 2013).…”

“…It has been suggested that little structure limits natural rumination, which in turn leads to frustration and stress in the calves and ultimately to the development of abnormal oral behaviors (Mattiello et al, 2002;Webb et al, 2013;Webb, 2014). Increased rumination can occur through increasing the provision of SF (Webb et al, 2012(Webb et al, , 2013, increasing the proportion of roughage or the presence of longer particles in the SF (Balch, 1971;Mertens, 1997;Kahyani et al, 2013), or providing coarser roughage sources (Mattiello et al, 2002;Webb et al, 2013). However, most studies ignore potential differences in satiety, by providing…”