Impacts of Reproductive Technologies on Beef Production in South America

The majority of beef cow herds in South America are constituted by Bos indicus females, which have particular reproductive features that contribute to reduced reproductive efficiency compared with that of B. taurus cohorts. Hence, several alternatives to enhance reproductive efficiency of B. indicus heifers and cows have been developed to address their inherent reproductive shortcomings. These research-based technologies are being described in detail within this chapter and have already made an impact on South American B. indicus-based production systems. These include the following: (a) hormonal protocols to induce puberty in nulliparous heifers or estrous cyclicity in postpartum cows to maximize their reproductive performance during the subsequent breeding season, (b) hormonal protocols to synchronize estrus and/or ovulation in B. indicus females to exploit their reproductive responses to artificial insemination, and (c) genetic and environmental factors that influence reproductive success in beef herds, including reproductive diseases and excitable temperament of B. indicus females, that have been investigated to support/promote the development of appropriate mitigation technologies.

Management of age at puberty in beef heifers to optimize efficiency of beef production

Age at puberty in beef heifers can influence economic efficiency of beef production through effects on both age at first calving (2 vs. 3+ years of age) and the time of conception of heifers in their initial breeding season. An overarching factor that influences age at puberty in heifers is nutritional management during both the preweaning period and between weaning and the breeding season. Age at puberty is heritable and selection for precocious puberty in populations such as the Nelore breed has the potential to substantially influence production efficiency. Highly effective hormonal technologies exist to aid in induction of puberty in well managed heifers. Age at first ovulation and pregnancy in heifers can be substantially influenced through implementation of nutritional and/or hormonal manipulation strategies. In the long term, combinations of genetic selection, nutritional strategies, and hormonal intervention when necessary will optimize efficiency of this aspect of beef production.

Current outlook and future perspectives of beef production in Brazil

Brazil is the world's largest beef exporter with the world's largest commercial cattle herd; however, the production cycle needs to be more efficient to supply internal and external demands in the future. Feedlot operations are currently a reality for the Brazilian beef cattle industry; nonetheless the beef cattle industry in Brazil is still based on grass-fed animals in which the Nellore breed predominates. At some point this constitutes an important advantage for Brazilian beef exportations because some countries look for “natural beef.” Brazilian packing plants regulate the use of antibiotics, especially ionophores used as growth promoters, on farms certified to export beef to European countries. In addition, the use of any implant or beta-agonist for cattle is forbidden in Brazil. From 1970 to 2006, the Brazilian bovine herd increased at 2.04%/year, total pasture at 0.07%/year, area with cultivated pasture at 3.5%/year, and ratio of animals/hectare of total pasture at 1.97%/year, whereas the area with natural pasture decreased at 2.26%/year. These trends alleviate some of the pressure on Brazilian authorities with respect to deforestation of the Amazon forest. Although Brazil had the greatest growth rate of enteric methane emissions, it also had the greatest growth rate of beef production, resulting in Brazil having a negative growth rate (–1.82%/year) of methane emissions per unit of product (kilogram of methane/kilogram of beef).

Drivers of change in animal protein production systems: changes from 'traditional' to 'modern' beef cattle production systems in Brazil

Until 1990, beef cattle production in Brazil was recognized as an enterprise of low investment, low cost of production, as well as an extensive production system that used large land areas to be economically feasible. The situation changed for the Brazilian beef market when the economy stabilized in 1994 and all sectors involved in the beef supply chain were able to predict their associated costs and profits. During the same period, purchasing power of the Brazilian population grew, and as a consequence, consumers began to demand higher quality beef products. This new scenario in the late 1990s and early 2000s has led to more intensive beef production systems in Brazil as well as the need for a greater understanding of how technologies might be applied. As consequence of this evolution, in the last five years, a necessity to increase beef production has occurred. The quality of Brazilian beef has improved compared with beef produced 15 years ago, but continued improvements are needed to achieve excellence in terms of large-scale production of high quality beef, be sustainable over a long period of time, and increase our contribution to global food security.

Prospecting candidate SNPs for backfat in Canchim beef cattle

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

BILL E. KUNKLE INTERDISCIPLINARY BEEF SYMPOSIUM: Temperament and acclimation to human handling influence growth, health, and reproductive responses in Bos taurus and Bos indicus cattle

Temperament in cattle is defined as the fear-related behavioral responses when exposed to human handling. Our group evaluates cattle temperament using 1) chute score on a 1 to 5 scale that increases according to excitable behavior during restraint in a squeeze chute, 2) exit velocity (speed of an animal exiting the squeeze chute), 3) exit score (dividing cattle according to exit velocity into quintiles using a 1 to 5 scale where 1 = cattle in the slowest quintile and 5 = cattle in the fastest quintile), and 4) temperament score (average of chute and exit scores). Subsequently, cattle are assigned a temperament type of adequate temperament (ADQ; temperament score <= 3) or excitable temperament (EXC; temperament score > 3). To assess the impacts of temperament on various beef production systems, our group associated these evaluation criteria with productive, reproductive, and health characteristics of Bos taurus and Bos indicus-influenced cattle. As expected, EXC cattle had greater plasma cortisol vs. ADQ cattle during handling, independent of breed type (B. indicus x B. taurus, P < 0.01; B. taurus, P < 0.01; B. indicus, P = 0.04) or age (cows, P < 0.01; heifers or steers, P < 0.01). In regards to reproduction, EXC females had reduced annual pregnancy rates vs. ADQ cohorts across breed types (B. taurus, P = 0.03; B. indicus, P = 0.05). Moreover, B. taurus EXC cows also had decreased calving rate (P = 0.04), weaning rate (P = 0.09), and kilograms of calf weaned/cow exposed to breeding (P = 0.08) vs. ADQ cohorts. In regards to feedlot cattle, B. indicus EXC steers had reduced ADG (P = 0.02) and G:F (P = 0.03) during a 109-d finishing period compared with ADQ cohorts. Bos taurus EXC cattle had reduced weaning BW (P = 0.04), greater acute-phase protein response on feedlot entry (P <= 0.05), impaired feedlot receiving ADG (P = 0.05), and reduced carcass weight (P = 0.07) vs. ADQ cohorts. Acclimating B. indicus x B. taurus or B. taurus heifers to human handling improved temperament (P <= 0.02), reduced plasma cortisol (P < 0.01), and hastened puberty attainment (P <= 0.02). However, no benefits were observed when mature cows or feeder cattle were acclimated to human handling. In conclusion, temperament impacts productive, reproductive, and health characteristics of beef cattle independent of breed type. Hence, strategies to improve herd temperament are imperative for optimal production efficiency of beef operations based on B. taurus and B. indicus-influenced cattle.

Abordaje práctico sobre cómo mejorar el bienestar en los bovinos

Current challenges of humanity require a new paradigm for animal production, and invest time and attention to the development of new production techniques that take into account the principles of sustainability and animal welfare science. To do this, we must be committed to promoting animal welfare and health, ensure environmental sustainability, consumer satisfaction and profitability for producers. To change our relationship with animals there is no need for changes in market conditions or large investments, it is enough to know better the needs of the animals we raise, the management system adapted to its characteristics. Even in the most favorable management conditions, on farms that have technological resources and trained personnel, there is much to change, especially in the daily management of the animals. Some of the risks more evident in the traditional systems of beef production are: problems during parturition, morbidity and mortality of calves, lack of shade in the pastures, improper handling of animals, risk of injury, inadequate infrastructure, poor management practices during routine processing (marking, castration, vaccination, dehorning), poor welfare during loading, transport, unloading and slaughter. To remedy this, you can adopt good management practices, which have been shown to reduce risk and improve the welfare of cattle in different stages of the production chain. The objective of this review is to show some of the risks that reduce the welfare of cattle and examples of how the adoption of best management practices impact on improving the productivity of these production systems. Finally, some indicators for assessing welfare in production systems are shown.

Desempenho e qualidade da carne de bovinos Nelore e F1 Brangus × Nelore recebendo suplemento com cromo complexado à molécula orgânica na terminação a pasto

Objetivou-se avaliar o efeito da suplementação com cromo complexado à molécula orgânica do suplemento no desempenho produtivo, nas características de carcaça e na qualidade da carne de bovinos terminados em regime de pastagem. Foram utilizados 18 bovinos Nelore e 18 F1 Brangus × Nelore castrados, com 16 meses de idade, mantidos com suplementação mineral protéica, com ou sem cromo complexado à molécula orgânica e abatidos aos 22 meses de idade. O ganho médio diário de peso vivo (GMD) não diferiu entre grupos genéticos, entretanto animais mantidos com suplemento contendo cromo apresentaram maior GMD (494 g) em comparação aos demais (420 g). A adição de cromo orgânico no suplemento não promoveu alterações na área de olho-de-lombo (63,42 cm²) e na espessura de gordura subcutânea do dorso (5,46 mm) e da garupa (5,58 mm), tomados por meio do ultra-som. O peso médio de carcaça quente foi 235 kg e o rendimento médio de carcaça quente, 52,09%, com superioridade do suplemento contendo cromo (238 kg e 52,9%) em relação ao controle (231 kg e 51,2%). Animais Nelore e F1 Brangus × Nelore apresentam potencial similar de produção de carne a pasto. A suplementação mineral protéica com adição de cromo complexado à molécula orgânica aumenta o ganho de peso e o rendimento de carcaça, mas não influencia os parâmetros qualitativos da carne.

Avaliação das respostas fisiológicas de bezerros Zebuínos puros e cruzados nascidos em clima subtropical

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Viabilidade econômica de quatro intensidades de pastejo do capim Tanzânia na pecuária de corte1

Were evaluated the economic effects of four grazing heights (20, 40, 60 and 80 cm) of Tanzânia grass for beef cattle. The total area was 12 acres divided into paddocks of one hectare, with three replications. We used three animals, males, Nelore per paddock, as more animals need additional adjustment to the height you want. The reduction in sward height allowed higher stocking rate, which, even with a reduction in individual performance, there was more beef production per area. The interest rate on capital given the property represented the largest share in the final cost of production. The participation of fixed variables showed a positive linear function of the increase in height from grazing, showing significant reduction of the production scale. A reduction in cost of production per hectare per year with increasing grazing height. No differences were found in certain economic indicators, and the four systems remunerate the capital invested.

Desequilíbrio de ligação e associação entre polimorfismos de base única com maciez da carne e espessura de gordura em bovinos Nelore utilizando painéis de alta densidade

Pós-graduação em Genética e Melhoramento Animal - FCAV

Desempenho, características de carcaça e da qualidade da carne de bovinos de corte terminados em confinamento

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Valor econômico e impacto da seleção para precocidade reprodutiva de fêmeas na raça Nelore

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Temperamento, desempenho e qualidade da carne de bovinos cruzados abatidos jovens

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Eficiência reprodutiva de fêmeas Nelore

Pós-graduação em Genética e Melhoramento Animal - FCAV