Tarcísio Ribeiro Paixão

Resumo Este manuscrito objetiva trazer informações globais sobre a produção de bezerros de origem leiteira para corte em confinamento, abordando aspectos como raça, sexo, idade, peso, consumo, digestibilidade, parâmetros ruminais, desempenho e características da carcaça, entre outros aspectos importantes, com base em artigos científicos e teses contendo dados atuais e relevantes. Incrementos da produção de leite no mundo e a utilização de novas tecnologias como seleção de raças com aptidão para produção de leite além dos importantes avanços no desempenho desses rebanhos, tem incrementado a oferta de bezerros machos leiteiros. Com exceção do uso desses animais para fins reprodutivos, a manutenção de touros leiteiros em fazendas de laticínios seria justificada se eles fossem destinados à produção de carne. Segundo a literatura consultada, o confinamento e a produção precoce com dietas de alto grão ou com alto conteúdo energético são as principais propostas de criação desses tipos de animais que é bem conhecido que esses bezerros não conseguem se adaptar as condições extensivas em comparação com raças especializadas para produção de carne. Também aspectos como requerimentos nutricionais, parâmetros ruminais e de desempenho vêm sendo estudados tanto na desmama, recria e terminação de bezerros de origem leiteira. Nesse sentido, vários trabalhos demonstram a relevância da criação e da adoção de bezerros de origem leiteira como uma fonte de proteína animal e apontam resultados de viabilidade econômica positivos, propondo então o aproveitamento por parte dos produtores com a finalidade de gerar renda extra para as fazendas.

This manuscript aims to provide comprehensive information on the production of dairy calves for beef in feedlot systems, addressing aspects such as breed, age, weight, intake, digestibility, ruminal parameters, performance, and carcass characteristics, among other relevant factors, based on a systematic review of scientific articles and theses containing current and pertinent data. Increases in global milk production and the use of new technologies, such as the selection of breeds with aptitude for milk production, along with significant advances in herd performance, have increased the supply of male dairy calves. Except for using these animals for reproductive purposes, the maintenence of dairy bulls on dairy farms would be justified if they were intended for meat production. According to the literature consulted, feedlot rearing and early production using high-energy diets are the main strategies for raising these animals, since it is well known that dairy calves cannot adapt to extensive systems as well as breeds specialized in meat production. Aspects such as nutritional requirements, ruminal parameters, and performance have also been studied during the pre-weaning, weaning, post-weaning, and finishing phases of dairy calves. In this context, several studies demonstrate the relevance of raising dairy calves as a source of animal protein and report positive results regarding their economic viability, thereby proposing their use as a means for producers to generate additional farm income.

The objective of this study was to evaluate the effect of concentrate supplementation on intake, apparent digestibility, feeding behavior, performance, carcass traits, centesimal composition, and fatty acid profile of meat from Girolando steers finished on tropical pasture during the dry season. Twenty castrated Girolando steers, aged 24 ± 2 months and weighing 371 ± 13.02 kg, were distributed in a completely randomized design. The animals were kept under intermittent grazing on Urochloa brizantha cv. Marandu for 135 days on 7.0 ha, divided into 14 paddocks. The animals received concentrate supplement at 3 g kg-1 or 6 g kg-1 of body weight (BW). Crude protein intake increased by 38% (P<0.05), and non-fiber carbohydrate intake increased by 15% with the increase in supplementation from 3 to 6 g kg-1 BW at finishing. Chewing time and the number of chews per cud were lower (P<0.05) in steers supplemented at 6 g kg-1 BW during finishing. Daily weight gain was 29% higher (P0.05) the weight, yield, or carcass fatness parameters of the steers. The 6 g kg-1 level resulted in meat with lower (P<0.05) levels of C15:0 and C14:1, as well as higher (P<0.05) proportions of n-6 fatty acids and a higher n-6:n-3 ratio. We recommend a concentrate supplementation level of 3 g kg-1 BW for steers finished on tropical pasture.

The study aimed to evaluate the effects of three supplementation strategies on intake, apparent digestibility, feeding behavior, performance, carcass traits, proximate composition, and the fatty acid profile of meat from steers on tropical pasture during the post-weaning and finishing stages. The experiment involved 33 1/2 Holstein × 1/2 castrated Zebu steers weighing 335 ± 42.90 kg, aged 22 ± 2 m. The animals were managed on Urochloa brizantha cv. Marandu using an intermittent grazing system with continuous stocking and variable stocking rates for 310 days. The supplementation strategies were as follows: MS/US (mineral salt/urea supplementation): mineral salt in the rainy season and mineral salt with urea in the dry season; US/PS1 (urea supplementation/protein supplementation): mineral salt with urea in the rainy season and protein supplement at 1 g/kg body weight (BW) in the dry season; and PS1/PS2 (protein supplementation 1/protein supplementation 2): protein supplement at 1 g/kg BW in the rainy season and 2 g/kg BW in the dry season. The dry matter intake did not differ significantly (p > 0.05) between strategies. However, the post-weaning PS1/PS2 strategy resulted in higher (p < 0.05) crude protein intake. The final body weight did not differ (p > 0.05) between the strategies, but the average daily gain in post-weaning and finishing was higher (p < 0.05) for MS/US (restricted) animals. Carcass weight, subcutaneous fat thickness, and lipid content in meat were significantly higher (p < 0.05) for steers in the PS1/PS2 group. Steers finished on MS/US produced meat with a higher content of polyunsaturated fatty acids and ω-3 fatty acids (p < 0.05). Concentrate supplementation at 1 g/kg BW during the rainy season and 2 g/kg BW during the dry season is recommended for post-weaning and finishing steers on tropical pasture.

The objective of this study was to examine the effect of the increasing levels of inclusion of palm kernel cake (PKC) in the diet on the performance of feedlot heifers. Forty-eight Nelore heifers with an initial weight of 274 ± 4.58 kg, at 24 months of age, were confined for 98 days in a feedlot. The animals were allocated to the four treatments in a completely randomized design. Treatments consisted of PKC levels of 0 (control), 10, 20, and [...] ABSTRACT The objective of this study was to examine the effect of the increasing levels of inclusion of palm kernel cake (PKC) in the diet on the performance of feedlot heifers. Forty-eight Nelore heifers with an initial weight of 274 ± 4.58 kg, at 24 months of age, were confined for 98 days in a feedlot. The animals were allocated to the four treatments in a completely randomized design. Treatments consisted of PKC levels of 0 (control), 10, 20, and

The objective of this work was to evaluate the non-carcass components of crossbred Santa Inês lambs finished in feedlot with the inclusion of different levels of red propolis extract (RPE). Thirty-five crossbred lambs were used with an average weight of 17.08 ± 2.36 kg and mean age of five months, distributed in a completely randomized design with five treatments and seven replications. The treatments evaluated were: 0; 7; 14 and 21 mL of extract/animal/day Before slaughter, each animal was individually weighed to obtain the body weight at slaughter (BWS). The weights and yields of non-carcass components were evaluated, weights and yields of regional dishes (Buchada and Panelada). The addition of different levels of red propolis extract (RPE) did not influence (p > 0.05) the weights and yields of non-carcass components, by-products and adipose deposits, to the weight and yield of regional dishes. The use of red propolis extract in diets up to the level studied (28 mL day-1) did not change the characteristics evaluated.

This study aimed to evaluate nutrient intake and digestibility, performance and economic viability of steers during the rearing phase in Brachiaria brizantha cultivar Marandu graze and in feedlot. Were used fifty crossbred steers in the rearing phase, with a mean weight of 275 ± 8.18 kg, distributed in a completely randomized design with ten replications per treatments: Mineral supplementation, nitrogen supplementation, Concentrate supplementation in the order of 1 and 2 g/kg body weight and total feedlot. The total dry matter intake and body weight showed a difference (P<0.05) for animals in feedlot. Crude protein, ether extract, neutral detergent fiber corrected for ashes and protein, non-fibrous carbohydrates, total digestible nutrients showed differences for the animals that received mineral supplementation in comparison to the other managements adopted. The same performance was observed for animals in feedlot. The digestibility coefficients of dry matter, crude protein, ether extract, non-fibrous carbohydrates and total digestible nutrients showed a difference (P<0.05) for the animals that received mineral supplementation, in comparison to the other managements adopted. (P<0.05). The mean daily gain was lower (P<0.05) for animals receiving mineral supplementation. The gross margin was higher (P<0.05) for animals handled in feedlot. Considering the obtained results, it was possible to observe that the animals kept in graze with good availability of dry matter presented satisfactory performance. It is feasible to confine the animals in rearing, since it shortens the production cycle, generating favorable economic results.

Palm kernel cake is a viable alternative for use in cattle feed to reduce production costs. The aim of this study was to evaluate the effects of concentrations in diet dry matter (DM) of palm kernel cake on intake and digestibility of nutrients and performance of cattle finished in a feedlot system. Forty non-castrated crossbred cattle, with an average age of 24 ± 2 months and an average weight of 331.12 ± 36.20 kg, were distributed among four treatments (control 0%, without heart of palm kernel cake in the diet; 8%, 16%, and 24% of palm kernel cake in diet DM). Variance and regression analysis were performed in function of the palm kernel cake concentrations in diet DM (P < 0.05). The dry matter intake decreased linearly (P < 0.05) as the concentrations in diet DM of palm kernel cake in the diet increased. The inclusion of palm kernel cake in the animals’ diet decreased (P < 0.05) on dry matter digestibility. No effects (P > 0.05) of palm kernel cake on average daily gain or feed conversion were observed. The palm kernel cake can be included in the diet of crossbred bulls finished in confinement at concentrations in diet DM of up to 24%, as it has not influenced performance.