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Effects of a fat and ground maize supplement on feed intake and digestion by cattle consuming bermudagrass hay (Cynodon dactylon)

1990; Elsevier BV; Volume: 30; Issue: 3-4 Linguagem: Inglês

10.1016/0377-8401(90)90018-4

1873-2216

K.L. Hall, A.L. Goetsch, K. M. Landis, L.A. Forster, A. C. Brake,

Genetic and phenotypic traits in livestock

Five beef cows (450 kg) and five Holstein steers (254 kg) were used in two Latin square experiments to determine the effects on intake and digestion of supplementing bermudagrass (Cynodon dactylon) hay with maize and fat, singly and in combination, and to compare fat poured on hay with fat mixed with maize. The cows received hay at 1.0% of their body weight (BW) per day alone (control) or with ground maize (0.49% BW) and/or fat (0.054% BW, beef tallow). Treatments were control (C), maize alone (MZ), fat poured on hay alone (PF), maize plus poured fat (MZ-PF) and maize mixed with fat (MZ-MF). Calcium carbonate (0.011% BW) was given to all supplemented animals. Mean ruminal fluid protozoal counts were higher with than without supplements (P < 0.05), for MZ than for PF, and for simultaneous vs. singular offering of maize and fat (P < 0.05). Flows of microbial organic matter and nitrogen at the duodenum were higher with than without supplements, for MZ than for PF, and for MZ-MF than for MZ-PF. Digestion of neutral detergent fiber in the whole tract declined with supplementation, but differences among supplement treatments were not significant. In the second study, steers received hay ad libitum and higher levels of supplements (maize 0.89, fat 0.099 and calcium carbonate 0.021% BW day−1). Total dry matter intake was C 5.86, MZ 7.86, PF 6.83, MZ-PF 7.90 and MZ-MF 7.75 kg day−1, being affected by supplementation and higher for MZ than PF (P < 0.05). Total tract neutral detergent fiber digestion was C 72.0, MZ 67.0, PF 69.2, MZ-PF 65.1, and MZ-MF 61.0%, and was depressed by supplementation and lower for simultaneous vs. singular supplementation with maize and fat (P < 0.05). In conclusion, there were no advantages in intake or digestion to adding fat to supplemental maize either separately or mixed as compared with supplementation with maize alone.