Use of exogenous fibrolytic enzymes and probiotic in finely ground starters to improve calf performance

Abstract

The present study investigated the effects of adding wheat straw treated with exogenous fibrolytic enzymes (EFE) and a probiotic supplement to finely ground starters on growth performance, rumen fermentation, behavior, digestibility, and health of dairy calves. A total of 48 Holstein dairy calves (39.8 ± 1.67 kg body weight) were randomly assigned to one of 4 nutritional treatments (n = 12 calves per treatment). The experiment was conducted in a 2 × 2 factorial arrangement of treatments consisting of two diets with or without EFE-treated wheat straw (2 g/day/calf) and diets with or without probiotics (2 g/day/calf). All calves were weaned on day 63 and remained in the study until day 84. The addition of EFE to wheat straw had no effect on starter feed intake, increased neutral detergent fiber (NDF) digestibility and recumbency, but decreased average daily gain (ADG) after weaning (240 g/d). The addition of probiotics to the diet had no effect on starter feed intake, improved feed efficiency, ADG (150 g/d), final weight (11.3 kg), and NDF digestibility, and decreased the ratio of acetate to propionate in the rumen. The addition of probiotics to starter feed for calves could improve their growth.

Figure 1

Body weight in calves receiving different experimental diets. Treatments were (1) calves fed diets without exogenous fibrolytic enzymes (EFE)-treated wheat straw and probiotic supplement (EFE-Pro−), (2) calves fed diets of EFE-treated wheat straw but with probiotic supplement (2 g/d/calf; EFE-Pro+), (3) calves fed EFE-treated wheat straw (2 g/d/calf) but without probiotic supplement (EFE+ Pro−), (4) calves fed EFE-treated wheat straw and probiotic supplement (EFE+ Pro+). Exogenous fibrolytic enzymes were applied to wheat straw. Data are presented as means ± SEM.

Figure 2

Starter feed intake in calves receiving different experimental diets. Treatments were (1) calves fed diets without exogenous fibrolytic enzymes (EFE)-treated wheat straw and probiotic supplement (EFE-Pro−), (2) calves fed diets of EFE-treated wheat straw but with probiotic supplement (2 g/d/calf; EFE-Pro+), (3) calves fed EFE-treated wheat straw (2 g/d/calf) but without probiotic supplement (EFE+ Pro−), (4) calves fed EFE-treated wheat straw and probiotic supplement (EFE+ Pro+). Exogenous fibrolytic enzymes were applied to wheat straw. Data are presented as means ± SEM.

Figure 3

Feed efficiency in calves receiving different experimental diets. Treatments were (1) calves fed diets without exogenous fibrolytic enzymes (EFE)-treated wheat straw and probiotic supplement (EFE-Pro−), (2) calves fed diets of EFE-treated wheat straw but with probiotic supplement (2 g/d/calf; EFE-Pro+), (3) calves fed EFE-treated wheat straw (2 g/d/calf) but without probiotic supplement (EFE+ Pro−), (4) calves fed EFE-treated wheat straw and probiotic supplement (EFE+ Pro+). Exogenous fibrolytic enzymes were applied to wheat straw. Data are presented as means ± SEM.

Figure 4

Principal component analysis (PCA) shows the interaction of the different experimental diets (colored) for all log-transformed and Pareto-scaled data for growth performance, health, and behavior. Treatments were (1) calves fed diets without exogenous fibrolytic enzymes (EFE)-treated wheat straw and probiotic supplement (EFE-Pro−), (2) calves fed diets of EFE-treated wheat straw but with probiotic supplement (2 g/d/calf; EFE-Pro+), (3) calves fed EFE-treated wheat straw (2 g/d/calf) but without probiotic supplement (EFE+ Pro−), (4) calves fed EFE-treated wheat straw and probiotic supplement (EFE+ Pro+). Exogenous fibrolytic enzymes were applied to wheat straw.