RESUMO
Our hypothesis is that crambe meal can totally substitute soybean meal and crude glycerin can partially replace the corn in the diet without leading to losses of nutrient intake and productive performance. Two assays were performed using heifers and steers. In the first assay, 24 Beefalo-Nellore heifers with 18 months old with 311.5 ± 5.5 kg, and in the second assay, 24 Beefalo-Nellore steers with 18 months old with 317.0 ± 6.4 kg were evaluated. The experiment was carried out in a randomized complete design, in a 2 × 2 factorial scheme, consisting of two energy sources (corn and crude glycerin) and two protein sources (soybean meal and crambe meal). Both assays had 104 experimental days of feedlot. There was no interaction between the variation sources. There was an effect of protein source on nutrient intake for heifers except to neutral detergent fiber intake, which presented effect of energy source. Heifers fed soybean meal showed higher results for total weight gain and daily weight gain. There was observed effect of energy source on rib eye area and subcutaneous fat thickness. Steers fed soybean meal showed higher neutral detergent fiber intake and non-fibrous carbohydrates. Steers fed corn + crude glycerin showed higher results for total weight gain and daily weight gain. The steers fed soybean meal showed higher averages for subcutaneous fat thickness. Crambe meal and crude glycerin can be used as alternative sources of energy and protein to replace 100% of soybean and 50% of corn, respectively, for finishing Beefalo-Nellore cattle in a feedlot.
Assuntos
Ração Animal , Glicerol , Ração Animal/análise , Animais , Biocombustíveis , Bovinos , Dieta/veterinária , Feminino , Zea maysRESUMO
We evaluated the lipid level effects in the diet on performance, carcass, and meat characteristics of forty-eight steers and heifers, F1 Beefalo (Bostaurus taurus × Bison bison hybrid) × Nellore (Bos taurus indicus), 22 months old, being 24 steers (393.2 ± 15 kg) and 24 heifers (278.4 ± 8 kg). The animals were distributed in a completely randomized design in a 4 × 2 factorial scheme (lipid levels in diet 55-, 65-, 75-, and 85-g/kg dry matter obtained by whole sunflower grain Helianthus annuus and two sexes). Increased amounts of sunflower grain in diet linearly reduce the proportion of saturated fatty acids (FA) in longissimus thoracis. Diets containing up to 85 g/kg of lipid can be used without negative effects on intake, carcass, and meat quality of Beefalo-Nellore steers and heifers and can be an effective strategy to reduce the proportion of saturated FA and increase unsaturated FA on the meat, which can be beneficial for human consumption.
Assuntos
Ácidos Graxos , Helianthus , Ração Animal/análise , Animais , Bovinos , Dieta/veterinária , Feminino , Carne/análise , SementesRESUMO
BACKGROUND: Nutrition is one of the most important factors that affect animal performance, and it therefore also impacts on financial results in beef systems. In this way, finding the best strategy for feeding supplements is of paramount importance. Aiming to evaluate the effect of supplement feeding strategies for beef cows in the last third of gestation, two experiments were conducted. In Experiment 1, 35 pregnant Nellore cows were assigned to a completely randomized design with four treatments: control, which received no supplement; supplementation for the last 30 d of gestation (30-d; 3.0 kg/d); supplementation for the last 60 d of gestation (60-d; 1.5 kg/d); or supplementation for the last 90 d of gestation (90-d; 1.0 kg/d). All supplemented treatments received the same total amount of supplement throughout the experiment: 90 kg (20% of crude protein). A second experiment (Experiment 2) was delineated to evaluate the effects of the amounts offered in Experiment 1 on intake and metabolism. Four multiparous pregnant Nellore cows were assigned to a 4 × 4 Latin square design, with periods of 15 d each. RESULTS: There was a linear effect of the number of days of supplementation on calving body weight (BW; P < 0.05) and a quadratic effect on BW change from parturition to d 31 post-calving (P < 0.05), with cows on the 60-d strategy losing less BW post-calving. No difference was found in offspring birth BW (P > 0.10). A significant linear effect on interval from parturition to conception (P < 0.05) was observed, with the highest calving to conception interval being observed in the 90-d strategy. The level of supplementation did not affect forage intake or neutral detergent fiber digestibility (P > 0.10). Nitrogen excreted through urine tended to increase linearly with the level of supplementation (P < 0.10). CONCLUSION: Providing 1.5 kg of supplement during the last 60 d of gestation improves cow performance after calving, reducing the magnitude of BW lost, and reduces the number of days from calving to re-conception in the following breeding season compared to the usually recommended period of supplementation of 90 d pre-partum.
RESUMO
The present study was conducted to evaluate the effects of high and low supplementation levels pre- and post-weaning on performance, endocrine, metabolic, and reproductive responses of Nellore heifers. Fifty Nellore heifers with 132 ± 9.9 kg average body weight (BW) and 138 ± 19 days of age were supplemented from 4 to 14 months. The heifers were distributed into five supplementation plans: HH-6 g/kg of BW of supplement pre- and post-weaning, HL-6 g/kg of BW of supplement pre-weaning and 3 g/kg post-weaning, LH-3 g/kg of BW pre-weaning and 6 g/kg of BW post-weaning, LL-3 g/kg of BW pre- and post-weaning, and CC-control, no supplementation. Interactions were not significant (P > 0.10). The level of supplement fed pre-weaning did not affect any of the performance variables evaluated at the end of the experiment (P > 0.10). There was a significant effect of supplementation and level of supplementation fed post-weaning on average daily gain (ADG) and final BW (P < 0.05). Overall ADG was also affected only by supplementation and level of supplement fed post-weaning (P < 0.05) with animals receiving 6 g/kg of BW post-weaning gaining more weight. Follicular diameter was greater in animals that received 6 g/kg of BW post-weaning (P < 0.05). In summary, performance, endocrine, metabolic, and reproductive variables evaluated in the current study were improved by the level of supplement fed post-weaning. Heifers receiving supplementation of 6 g/kg of BW post-weaning had greater responses, independent of the level received during the pre-weaning phase.