ABSTRACT The objective of this study was to investigate the effects of genetic group and calf sex on selling prices in auctions in the state of Santa Catarina (SC), Brazil. We evaluated 33,143 animals, representing 3,587 lots in 47 auctions from 2009 to 2014. The calves were classified according to genetic groups: British breed or crossbreed (BX); Continental breed or crossbreed (CX); Zebu breed or crossbreed (ZC); British and Continental crossbreed (BC); and Bos taurus and Bos indicus crossbreed (TI). The lots were composed of male and female calves. The years presenting low and high changes in the price of calves were similar to the variation in the price of beef cattle and, in 2014, the calf price reached its highest value (R$5.36). Male calves were sold at prices higher than female calves (average 7.8%), but this difference was driven by year of analysis, in which the closest approach occurred during periods of reduction in the price of live cattle in SC (2012 and 2013). Calves of genetic groups ZX and TI received, on average, lower prices (R$4.49 and R$4.64, respectively) compared with the other groups. In 2013, males from the BX group had greater variation in price compared with CX (3.9%) and BC (5.7%). On the other hand, female heifers from the BX group received higher average prices in 2011 compared with the CX, BC, IT, and ZX groups (8.1, 8.5, 14.7, and 16.5%, respectively). Recently, female British heifers have had a greater appreciation in auctions held in SC, possibly for their reproductive performance potential of beef cows. Thus, sex and different genetic groups are factors that impact the selling price of calves in the SC region.

The objective of this study was to determine the main causes of failure in bull breeding using a soundness evaluation in Rio Grande do Sul State/Brazil. We evaluated 19,836 bulls from 15 different breeds with ages ranging from two to eight years. The failures of bulls in each step were analyzed by logistic regression. The binary logistic regression was applied because the response variable had only two responses: Success (1) and Failure (0). Older bulls are more likely to be rejected than are younger bulls, regardless of their genetic group. Depending on the step of the assessment, one or another group is rejected. All steps of bull breeding soundness evaluation (BBSE) are important, with special attention to the failures of the behavioral evaluation (libido and physical ability). A BBSE performed before the breeding season reduces the risk of sub-fertile bulls in the herd.

Avaliou-se o impacto bioeconômico do exame andrológico na produção de bovinos de corte no Sul do Brasil. Foram comparados dois sistemas de produção similares com e sem a adoção do exame andrológico durante quatro anos no município de Júlio e Castilhos. A taxa de touros inaptos no primeiro exame foi de 22,8%. Com a realização do exame, obteve-se aumento de 31% na produção de bezerros, 13,8 bezerros/touro/ano e 24 kg de bezerros/vaca/ano. A relação benefício/custo sobre o investimento com o exame andrológico foi de R$ 35,84. O exame andrológico melhora os aspectos bioeconômicos de sistemas de cria de bovinos de corte.

It was evaluated the bioeconomic impact of the breeding soundness evaluation on beef cattle production in southern Brazil. Two similar production systems, with and without the use of breeding soundness evaluation, were compared during 4 years in the municipality of Júlio e Castilhos. The rate of unsound bulls in the first examination was 22.8%. By performing the examination, calf production increased by 31%, 13.8 calves/bull/year and 24 kg of calves/cow/year. The benefit/cost ratio on the investment with the breeding soundness evaluation was R$ 35.84. The breeding soundness evaluation improves bioeconomic aspects of beef cow-calf systems.