Exame andrológico em touros: qualidade dos indicadores da aptidão reprodutiva em distintos grupos raciais

Moraes, J. C. F.; Horn, Marilise Mesquita; Rosado, Adriano Garcia

doi:10.1590/s0103-84781998000400018

Cited by 17 publications

(17 citation statements)

References 5 publications

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“…The data presented in Table 3 shows that Braford bulls suffered a culling rate (32%) higher than that described in the literature for purebred breeds (Johnson et al, 1995;Bruner et al, 1995;Gottschall and Mattos, 1997;Ribeiro Filho et al, 1997), although similar breeding soundness culling rates have been reported for synthetic bulls (Chenoweth et al, 1996;Moraes et al, 1998;Chacon et al, 1999). In contrast to what we found for the Braford bulls, the reproductive fitness culling rate for the synthetic Brangus-Ibagé bulls was only 17% (Table 4).…”

Section: Discussionsupporting

confidence: 60%

“…In a population of 751 bulls raised in southern Brazil the culling rate due to alterations in semen quality was 47% for Braford bulls but only 18% for Hereford bulls raised under the same conditions (Moraes et al, 1998). According to various authors between 80 and 90% of purebred animals have no reproductive problems (Johnson et al, 1995;Bruner et al, 1995;Gottschall and Mattos, 1997;Ribeiro Filho et al, 1997;Kennedy et al, 2002) but in their study of 48 crossbred bulls Rao and Rao (1991) found that only 47% could be considered reproductively sound.…”

Section: Introductionmentioning

confidence: 98%

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Reproductive deficiency in bulls from synthetic breeds according to the type of crossbreed and the morphology of the Y chromosome

et al. 2005

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We used 550 Braford and 214 Brangus-Ibagé bulls to study the association between Y chromosome morphology and the evaluation of breeding-soundness, karyotyping and breeding records were used to assess Y chromosome morphology. In general, no direct association was detected between the individual type of Y chromosome and reproductive fitness as previously estimated through breeding soundness examination. The type of breeding strategy used to form the synthetic breeds was also analyzed. The Braford breed is about 3/8 Zebu (Bos taurus indicus) and 5/8 Hereford (Bos taurus taurus) but when the breeding strategy used 1/4 Zebu animals to produce Braford bulls which were 3/8 Zebu a greater percentage of the bulls had to be culled due to reproductive problems. Our study shows that certain interactions between genotypes can be detrimental to the reproductive efficiency of 3/8 Zebu animals and that breeding strategies avoiding or favoring certain genotypes can be used to reduce the percentage of bulls from synthetic breeds that are culled due to problems with semen quality.

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Section: Discussionsupporting

confidence: 60%

Section: Introductionmentioning

confidence: 98%

Reproductive deficiency in bulls from synthetic breeds according to the type of crossbreed and the morphology of the Y chromosome

et al. 2005

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“…Esta reduzida fertilidade deve-se, em grande parte, a problemas reprodutivos nas fêmeas, agravados por condições desfavoráveis de manejo e ambiente, mas os machos também influenciam este quadro, pois estudos têm evidenciado expressiva freqüência de animais com inadequada capacidade reprodutiva (Carrol et al, 1963;Coulter & Kozub, 1989;Fonseca et al, 1997;Moraes et al, 1998). O fato de existir grande variabilidade no desempenho dos touros é relevante devido ao expressivo número de fêmeas submetidas ao sistema de monta natural no Brasil e enfatiza, portanto, a necessidade de selecionar animais geneticamente superiores, capazes de influenciar parâmetros associados a um melhor desempenho do rebanho, como precocidade sexual e fertilidade.…”

Section: Introductionunclassified

Desenvolvimento ponderal e testicular, concentrações periféricas de testosterona e características de abate em touros da raça Nelore

2002

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RESUMO -Um experimento foi conduzido com o objetivo de avaliar o desenvolvimento ponderal e testicular, as concentrações periféricas de testosterona (T) e características de abate, dos 10 aos 30 meses de idade, em tourinhos da raça Nelore (n=27). Entre 11 e 21 meses, os animais foram tratados com GnRH e amostras de sangue, coletadas 0, 1,5 e 3,0 horas depois. Aos 30 meses, os animais foram abatidos. O peso vivo (PV) dos animais variou de 195,2 ± 3,8 kg a 439,1 ± 8,1 kg entre 10 e 30 meses e o rendimento de carcaça foi de 55,4 ± 2,3%. Os pesos dos testículos (PT) e do epidídimo (PE) aos 30 meses foram 160,9 ± 7,7 g e 20,4 ± 0,62 g, respectivamente.As concentrações de T apresentaram crescimento maior entre 16 e 18 meses e o tratamento com GnRH ocasionou aumentos nos níveis de T em todas as idades. As concentrações de testosterona estimuladas com GnRH estiveram associadas às concentrações basais (r = 0,41 a 0,63). Houve correlações entre PV e circunferência escrotal (CE) em todas as idades (r = 0,41 a 0,70). O peso corporal entre 10 e 30 meses apresentou correlações com PT (r = 0,48 a 0,62) e PE (r = 0,48 a 0,73) aos 30 meses e animais com maior peso de carcaça também tiveram maiores pesos testicular (r = 0,45) e epididimal (r = 0,63). Houve correlações entre PV (10 e 30 meses) e peso da carcaça (r = 0,65 a 0,93), mas o rendimento de carcaça não apresentou relação com CE, PT, PV ou níveis de testosterona. Foram significativas também as correlações entre a CE aos 30 meses e a CE avaliada entre 10 e 25 meses (r = 0,51 a 0,89). Portanto, medidas testiculares são potenciais indicadores do desenvolvimento ponderal e das características de abate na fase adulta.Palavras-chave: carcaça, circunferência escrotal, GnRH, Nelore, testosterona Testicular and Body Growth, Peripheral Concentrations of Testosterone and Carcass Parameters in Nelore BullsABSTRACT -An experiment was carried out to evaluate testicular and body growth, peripheral concentrations of testosterone (T) and carcass parameters, from 10 to 30 months of age, in Nelore bulls (n=27). Between 11 and 21 months, animals were treated with GnRH and blood samples taken 0, 1.5 and 3.0 hours afterwards. Animals were slaughtered at 30 months. Body weight (BW) varied from 195.2 ± 3.8 kg to 439.1 ± 8.1 kg between 10 and 30 months of age and the ratio BW/carcasss was 55.4 ± 2.3%. Testicular (TW) and epididimal weight (EW) at slaughter were 160.9 ± 7.7 g and 20.5 ± 0.62 g, respectively. Testosterone secretion reached higher levels between 16 and 18 months and treatment with GnRH caused increases in testosterone at all ages. Moreover, basal concentrations of T were related to those determined after GnRH (r = 0.41 to 0.63). Body weight from 10 to 30 months was correlated with SC at all ages (r = 0.41 to 0.70) and with testicular (r = 0.48 to 0.62) and epididymal weight (r = 0.48 to 0.73) at 30 months. Carcass weight was related to TW (r = 0.45) and EW (r = 0.63). Body weight evaluated from 10 to 30 months was related to carcass weight (r = 0.65 to 0.93), but the ratio BW/carcass...

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“…BSE allows the obtaining of information about the potential fertility of bulls, and its importance has been reported by several authors such as Lagerloff (1936), Silva et al (1981), Fonseca et al (1997), Moraes et al (1998), Menegassi et al (2008) and Lopes et al (2009). However, the economic advantages of bull BSE prior to the breeding season still have to be further investigated, because the current studies about bioeconomic impact of technologies are related mainly to beef heifers (Pfeifer et al, 2008) and few of them relate the use of technology with the BSE in bulls.…”

Section: Introductionmentioning

confidence: 94%

Bioeconomic impact of bull breeding soundness examination in cow-calf systems

et al. 2011

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-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.

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Exame andrológico em touros: qualidade dos indicadores da aptidão reprodutiva em distintos grupos raciais

Cited by 17 publications

References 5 publications

Reproductive deficiency in bulls from synthetic breeds according to the type of crossbreed and the morphology of the Y chromosome

Reproductive deficiency in bulls from synthetic breeds according to the type of crossbreed and the morphology of the Y chromosome

Desenvolvimento ponderal e testicular, concentrações periféricas de testosterona e características de abate em touros da raça Nelore

Bioeconomic impact of bull breeding soundness examination in cow-calf systems

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