RESUMOObjetivou-se avaliar o efeito da queima e do tratamento com aditivos químicos (uréia, benzoato de sódio e hidróxido de sódio) e inoculantes microbiológicos (Propionibacterium acidipropionici + Lactobacillus plantarum e Lactobacillus buchneri) na ensilagem da cana-de-açúcar, utilizando o esquema fatorial 2 (cana-de-açúcar crua e queimada) x 6 (cinco aditivos uréia, benzoato de sódio, hidróxido de sódio, Propionibacterium acidipropionici + Lactobacillus plantarum e Lactobacillus buchneri mais o grupo controle). Avaliou-se a composição química da forragem antes de ensilar e após a abertura dos silos. Observou-se concentração dos teores de FDN em todas as silagens, de 51,3% (antes da ensilagem) para 67,8% após a abertura dos silos. Maiores recuperações da matéria seca digestível verdadeira, 83,6 e 79,8% foram observadas nas silagens de cana-de-açúcar queimada e tratadas com NaOH ou com L. buchneri, respectivamente. Observou-se elevação da recuperação da matéria seca digestível de 45% nas silagens de cana crua controle para 74,3% nas silagens tratadas com L. buchneri. Nas silagens de cana queimada as melhores recuperações dessa fração foram observadas nas silagens tratadas com NaOH (83,6%) e nas com L. buchneri (79,8%). Os aditivos NaOH e L. buchneri foram os mais eficientes em controlar as perdas qualitativas durante o processo fermentativo da ensilagem da cana-de-açúcar crua ou queimada. SUMMARYThe objective of this trial was to evaluate the effect of the chemical (urea, sodium benzoate, and sodium hydroxide) and microbiological (Propionibacterium acidipropionici + Lactobacillus plantarum, and Lactobacillus buchneri) additives on the sugarcane nutritive value, ensiled crude or after burned, using a factorial scheme 2 (burned or crude sugar cane) x 6 (five additives urea, sodium benzoate, sodium hydroxide, Propionibacterium acidipropionici + Lactobacillus plantarum, and Lactobacillus buchneri plus control). It was evaluated the sugar cane chemical composition, before and after ensilage. The sugar cane NDF contents increased (51.3%, before ensilage) to 67.8% after fermentation period. The highest true digestible dry matter recovery values, 83.6 and 79.8% were observed on the burned sugar cane silage treated with NaOH or L. buchneri, respectively. The NaOH, and L. buchneri showed more efficiency in reducing nutritive looses during the fermentation phase of the crude or burned sugar cane silage.

In Brazil, the beef cattle are widely raised in pasture post weaning, but the supplementation has been studied only in individual phases of the animal's growth curve. Therefore, the objective of this study was evaluated the nutritional interrelationship between the growing and finishing phases in the performance of Nellore bulls. Eighty-four weaned calves (body weight [BW] = 205 ± 4.7 kg; 8 months) raised on pasture during the growing phase (dry season, summer and autumn) and finished in feedlot were used. The experiment was conducted as a randomized block design with a 2 × 2 × 3 factorial arrangement of treatments. Factors included 1) two supplements levels in the dry season (protein [1 g/kg BW/day-PR1] or protein-energy [3 g/kg BW/day-PE] supplement); 2) two supplement levels in summer (mineral supplement [ad libitum-MS] or protein supplement [1 g/kg BW/day-PR2]); and three supplement levels in autumn (MS, PR2 or PE). The animals were finished with a common diet. The dry season supplementation affected the average daily gain (ADG) in the summer (P < 0.05). In summer, animals fed MS had a greater ADG when fed PR1 in the previous (dry) season than those receiving PE (0.696 vs. 0.581 kg, P < 0.01); while, no difference in ADG was observed when the animals received PR2 (0.815 kg, P = 0.99). In autumn, animals fed PR2 in the previous (summer) season exhibited 11.3% lower ADG than those supplemented with MS (0.503 vs. 0.567 kg, P < 0.01), regardless of the autumn supplementation. Dry season supplementation did not affect the ADG during finishing phase (0.909 kg, P = 0.14). The animals fed PR2 in the summer and PE in the autumn had tendency of lower ADG during the feedlot (P = 0.06) compared with animals fed MS, however, they were finished 20 days earlier (P = 0.06). In conclusion, to provide PE in the dry season, followed by MS in the summer is not recommended, because this strategy reduces the ADG. In addition, dry season supplementation does not affect the ADG during finishing phase, while supply supplements of greater nutritional value in autumn reduces feedlot period.

Eighty-four Nellore bulls (269 ± 27 kg; 13 months) were used in a completely randomized design to evaluate different supplementation strategies on the performance of growing Nellore cattle grazing Panicum maximum cv. Tanzania in the rainy season and rainy-to-dry season transition. In the rainy season, 42 animals received mineral salt (MS) ad libitum and 42 received protein supplement (PR) at 1 g kg À1 body weight (BW). In the rainy-to-dry season transition, 28 animals received MS, 28 received PR at 1 g kg À1 BW, and 28 received a protein-energy (PE) supplement at 3 g kg À1 BW. In the rainy season, the PR supplement increased average daily gain (ADG), providing a significant increase of 17 kg in final BW. In the first period of the rainy-to-dry season transition, PE promoted better performance than MS, while PR did not differ from the two other treatments. In the second period of the rainy-to-dry season transition, PE and PR increased ADG by 41% and 31%, respectively, compared with MS. In the third period, all supplements differed from each other. Bulls fed PE had greater final BW compared with animals fed PR and MS. In conclusion, during the rainy season, PR supplementation should be provided even under good pasture conditions. Also, during the rainy-to-dry season transition, protein-energy supplementation is recommended to compensate for quantitative and qualitative deficiencies of the pasture. HIGHLIGHTS Nellore cattle being backgrounded on pasture with supplementation has greater body weight in the feedlot entry. Supplementation is recommended to compensate for quantitative and qualitative deficiencies of the pasture. Supplementation promotes a positive response in animal performance.

Context In the largest beef-producing countries in the world, the slaughter of female cows accounts for ~30–40% of all beef produced. Aims The objective of this study was to evaluate the replacement of a protein–energy supplement (PES) by a same-cost maize-based supplement (MBS) on the performance and final product of Nellore heifers grazing Brachiaria brizantha cv. Marandu pasture during the wet season in Brazil. Methods Ninety-six Nellore heifers of bodyweight (BW) 281 ± 7.55 kg and aged 23 months were used. Six were slaughtered at the start of the experiment. The remaining 90 heifers received one of the following three supplements with their predominantly pasture diet for 133 days: control, mineral salt ad libitum; PES, with protein 250 g/kg dry matter (DM) and total digestible nutrient 600 g/kg DM, offered at 3 g/kg BW.day (as-fed basis); MBS, with crude protein 90 g/kg DM and total digestible nutrient 850 g/kg DM, offered at 7 g/kg BW.day (as-fed basis). The variables were evaluated in a completely randomised block design with 30 heifers per treatment. Key results Average daily gain and final BW were similar (P &gt; 0.05) in PES and MBS treatments, and relative to the control increased (P &lt; 0.01) average daily gain by ~24% and final BW by 7%. Pasture intakes were decreased, with substitution levels of 8.0% for heifers receiving PES and 10.4% for those receiving MBS. Carcass weight (kg/day) and carcass gain (g carcass/kg BW) were greater (P &lt; 0.001) for heifers receiving MBS and PES than for the control group. Backfat depth was greater (P &lt; 0.001) in heifers receiving MBS (7.91 mm) than in those receiving PES (6.25 mm), and the lowest (P &lt; 0.001) measurement was observed in the control group (4.85 mm). Conclusions Maize-based supplement (7 g/kg BW.day) provided the same growth rate as PES (3 g/kg BW.day) but yielded heavier and slightly fatter carcasses of pasture-finished Nellore heifers during the wet season (133 days) with a similar cost, and with more total digestible nutrients than pasture plus mineral salt. Implications Maize-based supplement provided to Nellore heifers on pasture may improve performance despite lower pasture intakes but needs to be evaluated carefully in terms of costs involved.