ABSTRACT We investigated the impact of weaning at 30, 75, and 180 days of age on performance, body measurements, and rumen development (using the β-hydroxybutyrate biomarker) of beef calves until 190 days of age. A total of 64 Brangus calves were assigned to three treatments: hyper-early (W30), weaned at 32±0.89 days of age (n = 22, 10 males and 12 females); early (W75), weaned at 77±0.95 days of age (n = 20, 12 males and eight females); and conventional (W180), weaned at 183±0.82 days of age (n = 22, 13 males and nine females). Body weight (BW), average daily gain (ADG), β-hydroxybutyrate (βHBA), and morphometric measurements were evaluated. These variables were influenced by an interaction between treatment and days and were not affected by the sex of calves. The W30 calves experienced weight loss from 30 to 40 days of age compared with the W75 and W180 calves. Consequently, at day 75, W30 animals were lighter and had lower body length, thoracic circumference, withers height, and croup height compared with the W75 and W180 calves. However, no significant differences in BW were observed among treatments at 85 days of age. Additionally, W30 calves exhibited higher ADG and a moderate correlation with βHBA levels. Weaning calves at 30 days of age may negatively affect their performance until the sixth week after weaning, but there is no impairment in performance at 190 days of age. 75 18 using βhydroxybutyrate β hydroxybutyrate biomarker 19 6 hyperearly hyper W30, W , (W30) 32089 32 0 89 32±0.8 n 22 1 females females) W75, (W75) 77095 77 95 77±0.9 20 W180, (W180) 183082 183 82 183±0.8 females. . BW, (BW) ADG, (ADG) βHBA, (βHBA) evaluated W3 3 4 W7 W18 Consequently length circumference However 8 Additionally levels 7 (W30 3208 32±0. 2 (W75 7709 9 77±0. (W180 18308 183±0. (BW (ADG (βHBA W1 (W3 320 32±0 (W7 770 77±0 (W18 1830 183±0 (W 32± 77± (W1 183±

Resumo O objetivo do presente estudo foi avaliar as características da carcaça e da carne de novilhos confinados no Brasil de acordo com o grupo genético por meio de uma revisão sistemática e meta-análise. Foi realizada busca eletrônica de artigos nas bases de dados Scielo e Google Acadêmico e os dados foram agrupados de acordo com a predominância genética. Os resultados foram testados quanto à heterogeneidade e submetidos ao teste de normalidade e teste F e as médias comparadas pelo teste de Tukey. Novilhos predominantemente britânicos foram terminados em idade mais jovem, necessitaram de tempos de confinamento mais longos e apresentaram menores pesos de carcaça quente e menores áreas de olho de lombo no abate. Os percentuais de carcaça muscular foram maiores nos novilhos Continentais e Sintéticos em relação aos Britânicos e Zebu, enquanto os percentuais de gordura foram maiores nos Britânicos e Zebu em comparação aos continentais e sintéticos. O marmoreio da carne foi maior nos novilhos britânicos, continentais e mestiços em relação aos novilhos sintéticos e zebuínos. A origem do novilho britânico permite menor idade de abate, embora leve à redução do peso da carcaça quente, enquanto a predominância genética do zebu pode produzir carcaças com alto percentual de gordura. metaanálise. metaanálise meta análise. análise meta-análise Tukey jovem abate zebuínos

Abstract The aim of the present study was to assess the carcass and meat characteristics of feedlot steers in Brazil according to genetic group through a systematic review and meta-analysis. An electronic article search was conducted at the Scielo and Google Scholar databases and data were grouped according to genetic predominance. The results were tested for heterogeneity and submitted to a normality test and F test and the means were compared by the Tukey test. Predominantly British steers were finished at a younger age, required longer confinement times and displayed lower hot carcass weights and smaller loin eye areas at slaughter. Muscle carcass percentages were higher in Continental and Synthetic steers compared to British and Zebu steers, while fat percentages were higher in British and Zebu steers compared to continental and synthetic breeds. Meat marbling was higher in British, continental and crossbreed steers compared to synthetic and zebu steers. A British steer origin allows for decreased slaughter age, although leading to reduced hot carcass weight, while a genetic Zebu predominance can produce high fat percentage carcasses. metaanalysis. metaanalysis meta analysis. analysis meta-analysis age breeds weight carcasses

ABSTRACT Traditional livestock productivity is hard to estimate, since it depends on a gamut of animal production indicators that are difficult to measure for many farms. Thus, we propose an analytical method for estimating productivity and understanding the importance of animal production indicators under different full-cycle cattle production systems in Brazil. To evaluate the impact of these indicators, equations were derived from a comutational model of herd evolution for estimating the output parameters of the system as follows: productivity per hectare (PH) and offtake rate (COR), as a function of the indicators; calving rate (CR), mating age (AM), age of slaughter (AS) and stocking rate (SR). For this analysis, twenty-seven scenarios (simulation data) of low to high productivity were used, resulting from the combination of the following factors and levels: 1) calving rate of 50, 65 and 80 %; 2) mating age of heifers of one, two and three, years of age; and 3) age at slaughter of one, two and three year old steers. The scenario with the highest impact for each parameter and the indicator of highest impact for each scenario were identified for the production conditions in the region. Under most scenarios, a reduction in mating age had a greater impact on the productivity indexes compared to a reduction in slaughter age. Appropriate management of available technologies enables farmers to compare the marginal impacts of specific indicators on full-cycle production systems for beef cattle.

ABSTRACT The objective of this study was to verify the association of improved native grassland and winter and summer pastures on the weaning rate in beef cattle production. Subsequently, we also verified the socioeconomic and productive characteristics related to the adoption of technologies to increase the weaning rate of the farmers. The survey was conducted with 73 producers of Hereford and Braford cattle in the state of Rio Grande do Sul, Brazil. A data analysis was performed using the minimum ordinal squares method and the regression analysis (Tobit). The results showed that cattle farmers who adopt winter pastures have greater weaning rates, and the factors that influence this adoption are related to a greater number of employees on the farm and the use of a crop-livestock production system. In addition, farmers who receive a greater number of technical assistance visits per year are more likely to adopt winter pastures and improved native grassland. This information can be useful in the formulation of technological dissemination programs that aim at a sustainable production of beef cattle.

RESUMO A pesquisa realizada objetivou analisar o panorama das patentes relacionadas a bem-estar em bovinos. Para tanto, realizou-se uma busca na base mundial de registro de patentes Questel Orbit, orientada para a existência de termos associados ao bem-estar em bovinos nos documentos de famílias de patentes. A investigação correspondeu ao período compreendido desde o início dos registros em 1967 até agosto de 2019. Dessa forma, obteve-se um portfólio inicial composto por 272 registros, e destes, 77 documentos eram concernentes a bovinos, com intervenções diretas ou indiretas na otimização do bem-estar. A análise dos dados ocorreu de forma quantitativa e por meio da classificação das famílias de patentes em sete categorias: nutrição, sanidade, manejo, genética, infraestrutura/instalações, indicadores fisiológicos e comportamentais e rastreabilidade/certificação. O maior número de famílias de patentes correspondeu às áreas de instalações rurais, nutrição animal, sanidade e novos indicadores fisiológicos e comportamentais, totalizando 73%. A distribuição temporal desses registros demonstra que o interesse dos pesquisadores quanto à promoção de inovações tecnológicas voltadas ao bem-estar iniciou-se em 1995, com expressividade a partir de 2013. Salienta-se ainda que o maior registro de famílias de patentes advém da China (51%), seguido dos Países Europeus que, em sua totalidade, respondem por 23% e pelos Estados Unidos (19%), ao passo que o Brasil representa apenas 6% do total dos documentos. Apesar dos recentes registros de patentes relacionados a bovinos, observa-se uma ascensão nos últimos anos, denotando o crescimento dos esforços para inovação tecnológica dessa cadeia produtiva acerca do bem-estar animal.

ABSTRACT The research carried out intended to analyze the panorama of patents related to welfare in cattle. To this end, a search was carried out on the worldwide Questel Orbit patent registration database oriented toward the existence of terms associated with welfare in cattle in the documents of patent families. The investigation corresponded to the period from the beginning of the registrations in 1967 until August 2019. In this way, an initial portfolio was created of 272 registrations. Of these, 77 documents were related to cattle, with direct or indirect interventions in the optimization of the welfare. Data analysis took place in a quantitative way and through the classification of patent families in seven categories: nutrition, health, management, genetics, infrastructure/facilities, physiological and behavioral indicators, and traceability/certification. The largest number of patent families corresponded to the areas of rural facilities, animal nutrition, health, and new physiological and behavioral indicators, totaling 73%. The temporal distribution of these records shows that the interest of researchers in promoting technological innovations focused on well-being began in 1995, with expressiveness from 2013. It should also be noted that the largest registration of patent families comes from China (51%), followed by European countries, which account for 23%, and the United States (19%), while Brazil represents only 6% of the total documents. Despite the recent patent registrations related to cattle, there has been an increase in recent years, denoting the growth of efforts for technological innovation of this productive chain regarding animal welfare.

RESUMO: O objetivo deste estudo foi avaliar a eficiência bioeconômica em sistemas de produção de bovinos de corte no sul do Brasil. A pesquisa foi realizada com 33 pecuaristas que operam com sistemas de produção baseado em ciclo completo, em áreas maiores ou iguais a 900 hectares. As respostas foram classificadas em dois fatores: tecnologia (TEC) e gestão (GES), os quais foram separados em subfatores com seus respectivos componentes. A análise de correspondência múltipla, teste de Tukey, análise de cluster e correlação de Pearson foram os procedimentos estatísticos. Os componentes do TEC estavam acima do normal para os pecuaristas brasileiros, mas a margem bruta ainda é menor do que a necessária para gerar recursos financeiros para uma remuneração adequada ao pecuarista. Os pecuaristas foram classificados em três grupos de acordo com a eficiência bioeconômica: baixo (BNE), intermediário (INE) ou alto nível de eficiência (ANE). O driver TEC diferenciou os clusters BNE x ANE e o GES, expresso principalmente em custos, o INE x ANE. A correlação positiva entre a idade no primeiro acasalamento e a idade ao abate no agrupamento ANE explica os custos mais elevados quando comparados aos INE, devido ao uso de recursos alimentares diferenciados. Os investimentos em tecnologias relacionadas à alimentação de rebanho no agrupamento ANE melhoraram a produtividade em apenas 20% e o custo por hectare em 95 USD ha-1 em comparação ao cluster INE. As principais diferenças entre os pecuaristas se devem ao uso de tecnologias relacionadas à alimentação e ao gerenciamento de custos. Portanto, antes de implementar uma nova tecnologia, uma avaliação econômica é necessária.

ABSTRACT: The objective of this study was to evaluate the bioeconomic efficiency of beef cattle production systems in the south of Brazil. A survey was conducted with 33 beef cattle farmers operating with complete cycle production systems in areas larger or equal to 900 ha. Answers were classified in two drivers, technology (TEC) and management (MAN), which were separated into subfactors with their respective components. Multiple correspondence analysis, Tukey test, cluster analysis, and Pearson correlation were the statistics procedures. The TEC components were above normal for Brazilian farmers, but the gross margin is still lower than that needed to generate financial resources for a proper remuneration of cattle farmer. Farmers were classified into three clusters according to bioeconomic efficiency: low (LEL), intermediate (IEL), or high-efficiency level (HEL). The TEC driver differentiated the LEL x HEL clusters and the MAN, mainly expressed in costs, the IEL x HEL. Positive correlation between age at first mating and age at slaughter in the HEL cluster explains the higher costs when compared to IEL because of the use of differentiated feed resources. Investments in technologies related to herd feeding in HEL cluster improved the productivity by only 20% and the cost per hectare by 95 USD ha-1 in comparison to IEL cluster. The main differences between farmers are because of the use of technologies related to feeding and cost management. Therefore, before implementing a new technology, an economic evaluation is necessary.

ABSTRACT This study assessed the risks of different management practices to increase pregnancy rate in beef cow-calf systems, aiming at assisting decision-making. The perception of 18 experts on animal sciences regarding the risks of 32 nutritional, breeding, and general management practices applied to increase pregnancy rate were evaluated through questionnaires. The experts were selected by a non-probability sampling of researchers on veterinary and animal sciences. In addition, five farmers and eight technical consultants were also selected. The questionnaire was applied during a face-to-face meeting. The risk of each practice was assessed according to four factors, namely, cost, technical knowledge, operational complexity, and flexibility, and an equation was developed to calculate this risk. The applied method allowed to determine the risk of each practice, obtaining results similar to those previously perceived by the experts. Operational complexity and cost had greater influence on the estimated risks compared with the other factors. Moreover, the increase of one unit in operational complexity and cost increased the perceived risk and the estimated risk scores in 0.43 and 0.28 points, respectively. Overall, the application of general management practices presented lower risk score compared with nutritional and breeding practices, which were not different from which other. Equations to estimate the risks of farm managers should routinely apply management practices to increase the efficiency of cow-calf production systems.

In this article we research the influence of different sources of carbohydrates (corn, soybean hulls or wheat bran) upon the digestive behavior of 24 confined castrated steers with an initial average age and weight of 20 months and 330 kg born from the cross between Charolais and Nellore. The diet was composed of 40% sorghum silage and 60% concentrate. The time spent on total ruminating (an average of 454.6 min/day) was not influenced by the source of carbohydrate. The animals from the wheat bran treatment spent less time idle (718 min) in relation to those on the corn and soybean hulls treatments, which did not differ between themselves (an average of 792 min/day). The steers from the wheat bran treatment remained less time feeding (184 min/day) compared with those fed the other treatments, whose average time of permanence in this activity was 214 minutes per day. The other studied variables did not present a significant difference between the treatments. Inclusion of wheat bran in the diet of the confined steers results in less spent time idle, while steers feeding on soybean hulls spend less time feeding. The use of corn, soybean hulls, or wheat bran in the diet of the confined steers does not affect the total cudding time.

The objective of this study was to evaluate behavior patterns of heifers grazing on black oat (Avena strigosa Schreb.) and ryegrass (Lolium multiflorum Lam.), fed supplementation with brown rice meal and/or protected fat. A total of 28 Charolais × Nellore crossbred heifers at average initial age of 18 months and with initial live weight of 274.9±4.97 kg were used in the experiment. Animals were kept in oat + ryegrass pastures and distributed in the following treatments: no supplementation; Megalac (MEG): protected fat supplementation; supplementation with brown rice meal (BRM); and supplementation with BRM + MEG. The neutral detergent fiber (NDF) intake of pasture either in kg or in percentage of live weight was not changed by supply of supplement, but increased linearly (0.045 kg per day) over grazing periods. Supplementation with BRM and BRM + MEG reduced grazing time, 49.63%, in relation to non-supplemented animals and animals supplemented with MEG, 63.13%. Feeding seasons per minute increased over the experimental period with reduction in time spent in each feeding station. The number of bites per feeding station decreased linearly, with a variation of 34.48% in the late grazing period. Heifers supplemented with BRM and BRM + MEG require less time for grazing and increase their idle time, with no modification in displacement patterns within the paddocks and pasture ingestion. Grazing and idle time does not change in the distinct periods of pasture use, but rumination time increases with days of pasture use and with increase in NDF intake.