Digestion and live-weight gain by beef cattle consuming bermudagrass supplemented with grain or different high-protein foodstuffs

Abstract

Two experiments were made to determine the effects on digestion characteristics and live-weight (LW) gain of cattle consuming bermudagrass of supplementing with ground maize, soya-bean meal or a maizegluten-blood meal mix alone or maize plus the protein supplements. Experiment 1 was a Latin-square design with 14-day periods using six beef cows fitted with rumen and duodenal cannulas (490 kg). Cows were given bermudagrass hay at 12-7 g/kg LW alone (control, C) or with 2-4 g/kg LW of ground maize (M), 0-98 g/kg LW of soya-bean meal (S), 0-53 g/kg LW of maize-gluten plus 0-17 g/kg (dry matter basis) of blood meal (GB), M plus S (M + S) or M plus GB (M + GB). Nitrogen (N) intake was 106, 123, 143, 148, 166 and 166 g/day; total N at the duodenum was 101, 124, 117, 126, 140 and 161 (s.e. 5-91) g/day; and post-ruminal N disappearance was 61, 77, 72, 84, 87 and 110 (s.e. 5-6) g/day for C, M, S, GB, M + S and M + GB, respectively. In experiment 2, 96 crossbred beef heifers (203 kg LW) implanted with 200 mg testosterone and 20 mg oestradiol benzoate were allotted to 12 groups by LW (two groups per treatment). Heifers grazed bermudagrass paddocks for 84 days in two 42-day periods and supplement treatments were those in experiment 1. A period x treatment interaction in LW gain was noted (P < 0-05). LW gain was 0-78, 0-81, 0-79, 0-76, 0-70 and 0-95 kg in period 1 and 0-46, 0-51, 0-56, 0-53, 0-64 and 0-61 kg in period 2 for C, M, S, GB, M + S and M + GB, respectively (s.e. 0-049). In conclusion, duodenal flow and post-ruminal disappearance of N were similar for the protein sources when offered singularly, but when given with maize values were greater for the mix of protein meals high in ruminal undegradable protein as compared with soya-bean meal. LW gain by heifer calves grazing bermudagrass was increased only by supplementation with ground maize plus the protein meal mix of low ruminal degradability.

Feed Supplements for Young Dairy Breed Calves After Turn-Out to Pasture: Effect on Weight Gain and Subclinical Coccidiosis in Organic Production Systems

“…In the present experiment, it was not possible to decide whether differences in energy or the combination of energy and protein are the reasons for the improved weight gain. Other feeding experiments with somewhat heavier implanted calves (anabolic steroids) (about 200 kg liveweight) on pasture supplemented with slowly degraded protein based on blood meal demonstrated an improvement of weight gain of 17-25% compared to supplementation with energy or protein alone (Goetsch et al, 1990). These results are not, however, directly applicable to an organic farming context, as protein supplementation often gives greater responses with implanted cattle than with unimplanted cattle (Goetsch et al, 1990).…”

“…Additionally, growth promoters are commonly used in many cattle production experiments, making the research results inapplicable to organic production. Thus, the few papers on supplementation with undegradable protein to grazing calves (Goetsch et al, 1990;Grigsby et al, 1991), have limited relevance to organic production systems and more information is needed on locally available concentrates.…”

Feed Supplements for Young Dairy Breed Calves After Turn-Out to Pasture: Effect on Weight Gain and Subclinical Coccidiosis in Organic Production Systems

“…Additionally, growth promoters are commonly used in many cattle production experiments, making the research results inapplicable to organic production. Thus, the few papers on supplementation with undegradable protein to grazing calves (Goetsch et al, 1990;Grigsby et al, 1991), have limited relevance to organic production systems and more information is needed on locally available concentrates.…”