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Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:29:37Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:37:36Z : No. of bitstreams: 1 2-s2.0-84880707101.pdf: 346774 bytes, checksum: 4320496d47ae066cc54846c930455c20 (MD5) Made available in DSpace on 2014-05-27T11:29:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-06-01 The objective of the present study was to evaluate the genetic and non-genetic effects that influencevigor at birth and preweaning mortality in Nellore calves. A total of 11,727 records of births that occurred between 1978 and 2006, offspring of 363 sires, were analyzed. Poor calf vigor at birth (VB) and preweaning mortality divided into stillbirth (SB), early mortality (EM) and total mortality (TM) were analyzed as binary variables. Generalized linear models were used for the evaluation of non-genetic effects and generalized linear mixed models for genetic effects (sire and animal models). The incidences were 4.75% for VB, 2.66% for SB, 5.28% for EM, and 7.99% for TM. Birth weight was the effect that most influenced the traits studied. Calves weighing less than 22kg(females) and less than 24kg (males) were at a higher risk of low vigor and preweaning mortality. Preweaning mortality was higher among calves born from cows aged .3 and .11 years at calving compared with cows aged 7 to 10 years. Male calves presented less vigor and higher preweaning mortality than female calves. Selection for postweaning weight did not influence preweaning mortality. The heritability estimates ranged between 0.01 and 0.09 for VB, 0.00 and 0.27 for SB, 0.03 and 0.17 for EM and 0.02 and 0.10 for TM. Stillbirth should be included as a selection criterion in breeding programs of Nellore cattle, alone or as part of a selection index, aiming to reduce preweaning mortality. © 2013 Sociedade Brasileira de Zootecnia. APTA; Pólo Regional da Alta Mogiana, Colina, SP Grupo ETCO - Grupo de Estudos e Pesquisas em Etologia e Ecologia Animal, Colina, SP Departamento de Zootecnia FCAV-UNESP, Jaboticabal, SP Centro APTA Bovinos de Corte - IZ/APTA/SAA-SP, Sertãozinho, SP Instituto de Zootecnia, Nova Odessa, SP Departamento de Zootecnia FCAV-UNESP, Jaboticabal, SP

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T19:07:55Z No. of bitstreams: 1 S1516-35982012000600016.pdf: 53115 bytes, checksum: 3179b9827c76c6cc4d598c4aac12af9b (MD5) Made available in DSpace on 2013-08-22T19:07:55Z (GMT). No. of bitstreams: 1 S1516-35982012000600016.pdf: 53115 bytes, checksum: 3179b9827c76c6cc4d598c4aac12af9b (MD5) Previous issue date: 2012-06-01 Made available in DSpace on 2013-09-30T20:12:42Z (GMT). No. of bitstreams: 2 S1516-35982012000600016.pdf: 53115 bytes, checksum: 3179b9827c76c6cc4d598c4aac12af9b (MD5) S1516-35982012000600016.pdf.txt: 36947 bytes, checksum: 94692b7af21ed0c19093541df6809e1f (MD5) Previous issue date: 2012-06-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:18:25Z No. of bitstreams: 2 S1516-35982012000600016.pdf: 53115 bytes, checksum: 3179b9827c76c6cc4d598c4aac12af9b (MD5) S1516-35982012000600016.pdf.txt: 36947 bytes, checksum: 94692b7af21ed0c19093541df6809e1f (MD5) Made available in DSpace on 2014-05-20T13:18:25Z (GMT). No. of bitstreams: 2 S1516-35982012000600016.pdf: 53115 bytes, checksum: 3179b9827c76c6cc4d598c4aac12af9b (MD5) S1516-35982012000600016.pdf.txt: 36947 bytes, checksum: 94692b7af21ed0c19093541df6809e1f (MD5) Previous issue date: 2012-06-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The objectives of this study were to estimate heritabilities and genetic and phenotypic correlations between carcass traits measured by ultrasound and other economically important traits generally used as selection criteria in beef cattle and to estimate the genetic changes in the carcass traits as a result of selection for post-yearling weight. Carcass traits measured by ultrasound at two ages (12 and 18 months) and the correlation of these traits with weight, hip height and body condition score of males (yearling) and females (post-yearling) were analyzed. Multi-trait analysis was performed using the restricted maximum likelihood method under an animal model. To demonstrate the effect of selection for growth, phenotypic and expected breeding value means of the carcass traits and weights according to selection line (Nellore control line, selection line and traditional line) were estimated using records from animals born in the last 3 years (2006 to 2008). The heritability estimates were high for longissimus muscle area (LMA) at 12 and 18 months of age (0.47 and 0.40, respectively). For fat thickness measures, heritabilities ranged from 0.37 to 0.29. Genetic correlations of the same trait between the two ages were high for LMA (0.95). The Nellore breed shows medium to high genetic variability in carcass traits measured by ultrasound at 12 and 18 months of age, and a greater response is expected if selection for backfat thickness is performed at about 12 months of age. Selection for higher body weight will lead to an increase of LMA at the two ages without reducing subcutaneous fat thickness. Instituto de Zootecnia Centro APTA Bovinos de Corte Universidade Estadual Paulista Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista Faculdade de Ciências Agrárias e Veterinárias

Avaliou-se o efeito da inclusão de zeólita na dieta de bovinos de corte sobre os parâmetros ruminais, as digestibilidades total e parcial, a produção de nitrogênio, a eficiência microbiana e as características do sangue. Os tratamentos, com base na matéria seca (MS) da dieta, foram: 0; 0,75; 1,5; 2,25 e 3,0% de zeólita. Utilizaram-se cinco bovinos machos mestiços, fistulados no rúmen e abomaso, alimentados com silagem de milho e concentrado, representando 65% de volumoso e 35% de concentrado. O delineamento utilizado foi em quadrado latino 5×5, com cinco períodos de 15 dias. Os animais receberam 15g de dióxido de titânio (TiO2) do terceiro ao 12º dia de cada período. Houve efeito (P

In this study, we have investigated the incidence of transplacental transmission of Anaplasma marginale in chronically infected cows with no history of acute anaplasmosis during gestation. In addition, we evaluated various techniques for detection of transplacental transmission ofA. marginale. Blood samples were collected from 30 cows at three different periods: at the time of artificial insemination, at gestational diagnosis, and after calving. Also, blood was collected from the newborn calves, including one sample before colostrum intake, and another three days after birth. A. marginale-specific antibodies were detected in 100% of the cows with an indirect fluorescent antibody test (IFAT), and in 97% of them, using an indirect enzyme-linked immunosorbent assay (ELISA). Also, we observed that all of the three-day-old newborn calves were seropositive by IFAT. According to polymerase chain reaction, 63.3% of the cows were carriers of A. marginale, as well as 6.7% of the newborn calves. This represented a transplacental transmission rate of 10.5%. Furthermore, a correlation of 93.3% was observed between the two serodiagnostic techniques, demonstrating that both ELISA and IFAT can be used in epidemiological surveys of A. marginale. These results confirm the occurrence of transplacental transmission of A. marginale in chronically infected cows and suggest the importance of this transmission route in areas of enzootic instability. O objetivo do estudo foi avaliar a transmissão transplacentária deA. marginale em bovinos de corte cronicamente infectados utilizando diferentes testes de diagnóstico. Amostras de sangue foram colhidas de trinta matrizes durante o período de inseminação artificial, no diagnóstico de gestação e após o parto. Foi colhido sangue dos bezerros antes da ingestão do colostro e três dias após o nascimento. Anticorpos foram detectados em 100% das matrizes pela Reação de Imunofluorescência Indireta (RIFI) e 97% pelo Ensaio de Imunoadsorção Enzimático Indireto (ELISA). Aos três dias de idade 100% dos bezerros estavam soropositivos na RIFI. Conforme os resultados da PCR, 63.3% das matrizes e 6.7% dos bezerros eram portadores do agente, representando taxa de transmissão transplacentária de 10.5%. Correlação de 93.3% foi observada entre os resultados das técnicas sorológicas, demonstrando que tanto ELISA quanto RIFI podem ser utilizadas em levantamentos epidemiológicos do agente. Os resultados confirmaram a transmissão transplacentária do agente em vacas cronicamente infectadas. Isto demonstra a importãncia desta via de transmissão do A. marginale em áreas de instabilidade enzoótica.

Avaliou-se o efeito de diferentes dietas sobre as características da carcaça e da carne de bovinos de corte em confinamento: dieta composta por silagem de milho e formulação fixa durante o período de confinamento (SMF); dieta composta por silagem de milho e formulação variável durante o período de confinamento (SMV); dieta composta por silagem de cana-de-açúcar e formulação fixa (SCF); dieta composta por silagem de cana-de-açúcar e formulação variável (SCV); SCV na metade inicial do confinamento e SMV no período final (SCV/SMV). O delineamento experimental foi inteiramente ao acaso, com cinco tratamentos e três repetições. Houve maior deposição de gordura renal-pélvica-inguinal (P=0,03), de gordura subcutânea (P=0,06) e de gordura na carcaça (P=0,06) nas dietas com silagem de milho (6,7kg; 6,2mm e 34,6%) em relação àquelas com silagem de cana-de-açúcar (5,3kg; 4,8mm e 31,7%). Houve maior (P=0,05) rendimento de contrafilé e de miolo de alcatra nas dietas com silagem de milho (10% e 6,9%) em relação às com silagem de cana-de-açúcar (9% e 6,6%). Não houve efeito das dietas sobre rendimento de cortes primários (P>0,1), perdas por cocção (P>0,3) e força de cisalhamento (P>0,1). O ajuste da formulação da dieta e a troca de silagem não influenciaram as características de carcaça e da carne. A utilização de silagem de cana-de-açúcar permitiu carcaças com acabamento satisfatório The effects of different diets on the carcass and meat characteristics of beef steers in feedlot were evaluated using the following: diet containing corn silage, with fixed formulation during the period of feedlot (CSF); diet containing corn silage, with variable formulation according to the phase of feedlot (CSV); diet containing sugar cane silage with fixed formulation (SCSF); diet containing sugar cane silage, with variable formulation (SCSV); CSV diet in initial half of feedlot and SCSV diet in final half (SCSV/CSV). A completely randomized experimental design with five treatments and three replicates (collective pens) was used. There was higher content of kidney-pelvic-inguinal fat (P=0.03), subcutaneous fat (P=0.06), and fat tissue (P=0.06) deposition in animals fed diets containing corn silage (6.7kg, 6.2mm, and 34.6%) as compared to those fed sugar cane silage (5.3kg, 4.8mm, and 31.7%). A higher (P=0.05) yield of strip loin and rostbiff (% of hindquarter) were measured in carcasses from animals fed diets containing corn silage (10% and 6.9%) than in carcasses from animals fed diets containing sugar cane silage (9% and 6.6%). No effects of the diets on yield of primary meat cuts of the carcass (P>0.1), cooking losses (P>0.3), and shear force (P>0.1), with averages of 23.4% and 4.4kgf/mIII. The adjustment of the diet formulation as the period of confinement and the exchange of silage did not affect the characteristics of carcass and meat. The use of sugar cane silage allowed carcasses with good finishing

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T19:06:52Z No. of bitstreams: 1 S1516-35982006000100036.pdf: 289634 bytes, checksum: 8d599a000205c8dc7919310e72bc8ec2 (MD5) Made available in DSpace on 2013-08-22T19:06:52Z (GMT). No. of bitstreams: 1 S1516-35982006000100036.pdf: 289634 bytes, checksum: 8d599a000205c8dc7919310e72bc8ec2 (MD5) Previous issue date: 2006-02-01 Made available in DSpace on 2013-09-30T20:11:19Z (GMT). No. of bitstreams: 2 S1516-35982006000100036.pdf: 289634 bytes, checksum: 8d599a000205c8dc7919310e72bc8ec2 (MD5) S1516-35982006000100036.pdf.txt: 49939 bytes, checksum: 25f90c6902b36c973e789676f2dd41a7 (MD5) Previous issue date: 2006-02-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T15:18:07Z No. of bitstreams: 2 S1516-35982006000100036.pdf: 289634 bytes, checksum: 8d599a000205c8dc7919310e72bc8ec2 (MD5) S1516-35982006000100036.pdf.txt: 49939 bytes, checksum: 25f90c6902b36c973e789676f2dd41a7 (MD5) Made available in DSpace on 2014-05-20T15:18:07Z (GMT). No. of bitstreams: 2 S1516-35982006000100036.pdf: 289634 bytes, checksum: 8d599a000205c8dc7919310e72bc8ec2 (MD5) S1516-35982006000100036.pdf.txt: 49939 bytes, checksum: 25f90c6902b36c973e789676f2dd41a7 (MD5) Previous issue date: 2006-02-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Vinte e quatro bovinos machos, castrados, Holandês x Zebu (peso vivo inicial de 435 kg e 36 meses de idade) foram distribuídos em um delineamento em blocos casualizados, com seis repetições para se avaliarem o consumo e a digestibilidade aparente total dos nutrientes, o ganho de peso, a conversão alimentar e o rendimento de carcaça em bovinos de corte recebendo dietas contendo silagem de sorgo e concentrado nas proporções 80:20, 65:35, 50:50 e 35:65, com base na matéria seca. Os consumos de MS, MO, PB e NDT, em kg/dia, não foram influenciados pelos níveis de concentrado nas dietas, enquanto os consumos de EE e MS (% PV e g/kgPV0,75) e os CNF, em kg/dia, aumentaram linearmente com o nível de concentrado. O consumo de fibra em detergente neutro (FDN), no entanto, independentemente da forma de expressão, decresceu linearmente com o aumento dos níveis de concentrado. As digestibilidades aparentes totais de MS, MO e CNF não foram influenciadas pelas dietas, registrando-se valores médios de 63,8, 65,1 e 82,2%, respectivamente. Entretanto, as digestibilidades aparentes de PB, EE e FDN reduziram linearmente com o incremento de concentrado às dietas. O ganho médio diário e a conversão alimentar não foram influenciados pelas dietas, com valores médios de 1,40 kg/dia e 8,08 kg MS/kg de ganho de peso vivo (GPV), respectivamente. O peso final médio dos animais foi de 523 kg. O rendimento de carcaça dos animais aumentou linearmente com o incremento dos níveis de concentrado nas dietas. A dieta com silagem de sorgo de boa qualidade, associada a 20% de concentrado, proporcionou produção de carne com menor custo que as demais dietas. Twenty-four castrated Holstein x Zebu bovines averaging 435 kg of initial body weight and 36 months of age were assigned to a randomized complete block design (six replications/treatment) to investigate the effects of sorghum silage with different concentrate levels on intake, apparent total tract digestibility, weight gain, feed conversion, and carcass yield. Animals received the following forage:concentrate ratios: 80:20, 65:35, 50:50, and 35:65 on dry matter basis. Different forage:concentrate ratios did not change significantly intakes of DM, OM, CP, and TDN all expressed in kg/day whereas intakes of DM (% BW and g/kg BW0.75) and EE and NFC both expressed in kg/day increased linearly with the concentrate level. Conversely, intake of NDF, independently of the expression form, decreased linearly when the concentrate level increased from 20 to 65% of the diet. Apparent total tract digestibilities of DM, OM, and NFC were similar across diets averaging 63.8, 65.1, and 82.2%, respectively. However, apparent total tract digestibilities of CP, EE, and NDF decreased linearly with the increment of concentrate in the diets. Both average daily gain and feed conversion were not affected by the diets averaging 1.40 g/day and 8.08 kg of DM/kg of body weight gain (BWG), respectively. The observed average final weight of the animals was 523 kg among diets in the present trial. Carcass yield of animals increased linearly when the forage:concentrate ratio went from 80:20 to 35:65. The diet with the forage:concentrate ratio of 80:20 resulted in lower meat production costs than diets with greater proportions of concentrate. UFV UFV Departamento de Zootecnia CNPq Unesp Universidade Presidente Antônio Carlos Unesp

Verificou-se a influência da heterogeneidade de variâncias na avaliação genética de bovinos de corte da raça Tabapuã. Dados de pesos corrigidos aos 120, 240 e 420 dias de idade foram estratificados com base no desvio-padrão fenotípico do peso aos 120 dias dos grupos de contemporâneos em três classes: baixo (18,9kg) desvio-padrão. Nas análises de múltiplas características, em que o peso foi considerado característica distinta em cada classe de desvio-padrão, constatou-se que as variâncias genéticas e residuais foram maiores com o aumento do desvio-padrão da classe. As herdabilidades foram 0,26, 0,32 e 0,37 (peso aos 120 dias), 0,28, 0,35 e 0,35 (peso aos 240 dias) e 0,14, 0,18 e 0,18 (peso aos 420 dias) nas classes de baixo, médio e alto desvio-padrão, respectivamente. As correlações genéticas entre o mesmo peso, nas classes de baixo e alto desvio-padrão foram inferiores a 0,80. As correlações entre os valores genéticos, obtidos de análises múltiplas e de análise geral (sem as classes), foram superiores a 0,93. Observou-se que os reprodutores seriam classificados de forma similar se for considerada ou não a presença de variâncias heterogêneas nas análises. Data from Tabapuã beef cattle were used to study the influence of variance heterogeneity on genetic evaluation. Adjusted weights at 120, 240 and 420 days of age were classified in three classes of standard deviation: low (18.9kg), based on phenotypic standard deviation of the weight at 120 days of age of the contemporary groups. Multiple trait analyses, considering each class of phenotypic standard deviation as a distinct trait, were performed. The genetic and residual variances increased as the phenotypic standard deviation of the class increased. Heritabilities for low, medium and high phenotypic standard deviation classes were 0.26, 0.32 and 0.37 (weight at 120 days), 0.28, 0.35 and 0.35 (weight at 240 days) and 0.14, 0.18 and 0.18 (weight at 420 days), respectively. Genetic correlations between the same weight, in low and high phenotypic standard deviation classes were lower than 0.80. The correlation between the breeding values, obtained from multiple trait analyses, and from general analyses (without classes), were greater than 0.93. It was observed that sires would be classified in similar way considering or not considering the heterogeneity of variances in the analyses.

Objetivou-se com este trabalho a validação do programa de computador do Sistema Viçosa de Formulação de Rações, bem como testar o NRC 1996 de gado de corte, incluindo os níveis 1 (Sistema NRC) e 2 (Sistema Cornell), para bovinos de corte em pastejo. Os dados de ganho de peso preditos pelos programas, em função do peso corporal, dos grupos genéticos e da composição e do consumo de suplementos, durante o período da seca, foram comparados com os dados observados. O Sistema NRC, níveis 1 e 2, subestimou o consumo de matéria seca em 12 e 13% e o ganho de peso, em 55 e 86%, respectivamente, de 35 novilhos suplementados em pastagens durante o período da seca. Já o Sistema Viçosa, com menor margem de erro, superestimou o consumo em 5% e subestimou o ganho em 11%. Em um segundo ensaio de validação com um banco de dados de 25 experimentos, 74 tratamentos e 1230 animais, o Sistema Viçosa superestimou o ganho de peso, em função do consumo de energia (NDT), em 44%. Apesar disto, o programa é adequado para ser utilizado nas formulações de suplementos alimentares para bovinos em crescimento em pastagens tropicais, uma vez que o consumo de alimentos e, conseqüentemente, o ganho de peso são altamente variáveis, devido à variação na disponibilidade e composição das pastagens, diversidades climáticas e genéticas dos animais. This work had as objective to validate the computer program of Sistema Viçosa de Formulação de Rações, as well as the 1996 beef NRC, including levels 1 (NRC system) and 2 (Cornell System) for growing beef cattle under pastures. The data of daily gain predicted by the programs as a function of body weight, genetic groups and supplements composition and intake during the dry season were compared to the observed values. The levels 1 and 2 of NRC system underpredicted dry matter intake in 12 and 13% and daily gain in 55 and 86%, respectively, of 35 supplemented steers in tropical pastures during the dry season. The Viçosa system overpredicted intake in 5% and underpredicted daily gain in 11%, with lower error. In a second validation assay with a data base of 25 experiments, 74 treatments and 1230 animals, the Viçosa system overpredicted the daily gain as a function of energy intake (TDN), in 44%. In spite of that, the program is adequate to be utilized in formulation of feed supplements for growing bovines in tropical pastures, as feed intake and so, daily gain are highly variable, due to variation in pastures availability and composition, and diversity of climate and animal genetic.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T19:06:06Z No. of bitstreams: 1 S1516-35982000000400010.pdf: 97525 bytes, checksum: 1dbd919a7ac1cf8768ae11ffe6702c98 (MD5) Made available in DSpace on 2013-08-22T19:06:06Z (GMT). No. of bitstreams: 1 S1516-35982000000400010.pdf: 97525 bytes, checksum: 1dbd919a7ac1cf8768ae11ffe6702c98 (MD5) Previous issue date: 2000-08-01 Made available in DSpace on 2013-09-30T18:02:08Z (GMT). No. of bitstreams: 2 S1516-35982000000400010.pdf: 97525 bytes, checksum: 1dbd919a7ac1cf8768ae11ffe6702c98 (MD5) S1516-35982000000400010.pdf.txt: 25900 bytes, checksum: 381ec0f0322ad45623d660dbe8de9847 (MD5) Previous issue date: 2000-08-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:18:44Z No. of bitstreams: 2 S1516-35982000000400010.pdf: 97525 bytes, checksum: 1dbd919a7ac1cf8768ae11ffe6702c98 (MD5) S1516-35982000000400010.pdf.txt: 25900 bytes, checksum: 381ec0f0322ad45623d660dbe8de9847 (MD5) Made available in DSpace on 2014-05-20T13:18:44Z (GMT). No. of bitstreams: 2 S1516-35982000000400010.pdf: 97525 bytes, checksum: 1dbd919a7ac1cf8768ae11ffe6702c98 (MD5) S1516-35982000000400010.pdf.txt: 25900 bytes, checksum: 381ec0f0322ad45623d660dbe8de9847 (MD5) Previous issue date: 2000-08-01 Esta pesquisa foi conduzida com o objetivo de avaliar o efeito da endogamia e suas possíveis influências sobre o crescimento de bovinos de corte. Foram utilizadas 27.406 observações de peso à desmama, padronizado aos 205 dias (PD), e 14.317 informações de peso ao ano, padronizado aos 365 dias (PA), de animais da raça Gir, no período de 1970 a 1995. As análises foram feitas pelo método dos quadrados mínimos, incluindo-se o efeito aleatório de grupo contemporâneo e os efeitos fixos de geração (discreto), idade da vaca ao parto e taxa de endogamia do bezerro e da vaca como variáveis contínuas, considerando-se os efeitos linear e quadrático. Apenas 11,65% das vacas, 19,84% dos touros e 9,23% dos bezerros da raça Gir estudados apresentaram algum grau de endogamia e as estimativas das médias de endogamia foram de pequena magnitude, constatando-se valores de 1,04; 0,96; e 1,66% para vacas, touros e bezerros, respectivamente. O efeito da endogamia do animal foi significativo e quadrático para as duas características estudadas. Os resultados mostraram depressão endogâmica para ambas as características (PD e PA). Recomenda-se evitar os acasalamentos, intencionalmente, endogâmicos e monitorar os acasalamentos com base no parentesco entre os indivíduos, visando manter baixas as taxas de endogamia. This research was carried out to evaluate the inbreeding effects and its possible influence on the beef cattle growth. Data with 27,406 observations of weaning weight, standardized to 205 (WW), and 14,317 observations of yearling weight, standardized to 365 days (YW), from Gyr breed animals, from 1970 to 1995, were used. The analysis were made using the least square method that included the random effect of contemporary group and the fixed effects of generation (class), age of cow at calving, calf and cow inbreeding as regressions, considering linear and quadratic effects. Only 11.65% of cows, 19.84% of bulls and 9.23% of the studied calves from the Gyr breed presented some degree of inbreeding. The estimates of the inbreeding means were of low magnitude and the values were of 1.04, 0.96 and 1.66% for cows, bulls and calves, respectively. The animal inbreeding was significant and quadratic for both studied traits. The results showed inbreeding depression for both traits (WW and YW). Intentional inbreeding matting should be avoided and matting should be planed also taking into account the relationship between the animals, in order to keep inbreeding in low degree. Universidade Estadual Paulista FCAV Departamento de Zootecnia Universidade Estadual Paulista FCAV Departamento de Zootecnia

Foram estudados os teores de Ca, P, Mg, K e Na dos solos e os teores destes elementos e de S das forrageiras predominantes nas pastagens e na água, nas regiões norte e noroeste do Estado do Rio de Janeiro, nas épocas seca (junho-julho) e chuvosa (dezembro-janeiro). Foram coletadas amostras de solo, forrageiras e água em 12 diferentes locais das regiões, em áreas onde predominam pastagens, identificadas por fotos obtidas por satélite e de acordo com as diferentes características dos solos. Os teores de minerais das amostras foram determinados por espectrometria via plasma, após preparados os extratos. Os níveis de P, K e Na nos solos foram muito baixos, bem como os de Ca, em alguns locais, em ambas épocas do ano. Também em alguns locais, foram encontrados baixos níveis de P nas amostras de forrageiras e houve variação desses níveis com o tipo de solo. Em alguns locais os teores de Ca das forrageiras foram adequados e os níveis de Mg, superiores às exigências de bovinos de corte em regime de pasto. Também, em ambas épocas, foram encontrados baixos níveis de Na nas amostras de forrageiras. Os níveis de K foram superiores às exigências desses animais. Somente em um local, o nível de Na na forrageira atingiu o máximo de 10% da exigência mínima dos bovinos e os de S, exceto em dois locais foram muito baixos. Amostras de água apresentaram níveis de Ca superiores a 70 mg/L e Na acima de 55,1 mg/L, mas os valores médios na maioria dos locais, foram muito baixos. Os teores médios de Na das águas foram quatro vezes superiores às médias encontradas nos Estados Unidos, os de K em alguns locais variaram de 2 a 6 vezes e os de S foram muito baixos. The amount of Ca, P, Mg, K and Na of the soils, and the levels of these elements and S of the forages predominant in the pastures and water, were studied in the North and Northwest regions of Rio de Janeiro State, in the dry (June-July) and rainy (December-January) seasons. Samples were collected from soil, forages and water from 12 different places of the regions, in predominant grazing areas, as showed by satellite photography and according to different soil characteristics. The mineral contents of the sample extracts were determined by spectrometry, on an inductive plasma emission source apparatus. The amount of P, K and Na in the soils were very low as well as for those of Ca in some places, in the dry and rainy seasons. Also, low levels of P were found in forage samples at some places and the forage P levels changed with the soil type. In some places, forage Ca levels were adequate and forage Mg levels were higher for the grazing beef cow requirements. Also, in both seasons low levels of Na were detected in the forage samples. The forage levels of K were higher for the requirements of these animals. Only in one place the forage Na content reached the maximum of 10% of the minimum required by these animals and forage S levels except in two places were low. Samples of water showed Ca contents over 70 mg/L and Na over 55,1 mg/L, but the mean values in most of the places were very low. The mean Na contents of water were found to be four times higher than those found in USA, those of K in some places ranged from two to six times and the S contents were very low.

Several studies have reported differences between male and female cattle in growing and body composition. The differences occur mainly by hormonal factors, however, there is little information about the relationship between sex and feed efficiency traits in beef cattle. The residual feeding intake (RFI) is a feed efficiency measurement and has been an alternative to improve the profit in beef production system. It is defined as the difference between dry matter intake observed and estimated by regression in function of weight gain and metabolic body weight. More efficient animals have the intake observed smaller than the predicted (low RFI), unlike the less efficient ones have the intake bigger than predicted (high RFI). This study aimed to evaluate the sex effect (male and female) on growing and feeding efficiency traits in young Nellore bulls selected for post weaning weight. Data from males and females Nellore animals obtained during RFI evaluation tests were utilized. The tests were performed at Centro APTA Bovinos de Corte – Instituto de Zootecnia - Sertãozinho-SP, between 2005 and 2011. The tests duration ranged from 56 to 112 days, with the adaption period raging from 28 to 56 days, depending of the year. At the tests beginning the animals had, on average, 286 ± 42 days of age. The traits analyzed were initial body weight (IBW), final body weight (FBW), average daily gain (ADG), dry matter intake (DMI) and RFI. Data were analyzed using de GLM procedure of the SAS program. The model of analyses included the fixed effects of contemporary group (year and selection line), sex (male and female) and age at the beginning of test as linear covariate. Means of growing traits were different between sex (Table 1), being males heavier than females at the begging (35.28%) and at the end (29.17%) of the test . Males gained 29% more weight than females. Considering DMI, males consumed 21% more food than females. These results showed that males had greater feed conversion, 6.70 kg DM kg-1 gain X 7.82 kg DM kg-1 gain. However, no significant differences were detected on RFI between the sex, showing an independent relationship between RFI and sex in beef cattle. Growth traits and feed intake were influenced by sex, however the efficiency of feed utilization, defined as RFI was not influenced by sex in young cattle Nellore.

The reactivity is an important behavioral trait that is directly linked to the economic characteristics of beef. Less reactive animals have better performance and efficiency, thus, this study aimed to evaluate the influence of reactivity in the animals´ classification for residual feed intake (RFI). The study was conducted at Centro APTA Bovinos de Corte – Instituto de Zootecnia -Sertãozinho/SP. Sixty males belonging to the Traditional Nelore herd were classified into high (> mean + 0.5 SD, n = 21), medium (±0.5 SD from mean, n = 20) and low RFI (

Summary Background: there is little information in Cuba regarding the genetic components of the postpartum period in beef cattle. Objective: to compare estimates of genetic parameters of days open (DO) obtained with three models in Charolais cattle of Cuba. Methods: data from individual reproductive control of Charolais cattle from 17 herds in two Cuban companies were analyzed. The sample consisted of 16,891 calvings from 4,593 cows, daughters of 190 sires and 2,770 dams. Up to 10 parities per female between years 1981 and 2005 were considered. The WOMBAT program was used to estimate variance components. Three models were applied; an univariate model (UM) for each separate parity until the sixth calving; a repeatability model (RM) with all parities; and a random regression model (ARM) taking the number of calving as an independent variable. Results: the overall average for DO was 171 ± 93 days. The trend of the average value for DO in each calving was decreasing from the first to the tenth parity, with a seasonal performance around 155 days between the fourth and eighth calving. DO heritability estimated by UM was variable, with values of 0.03 for the first calving and 0.06 for the sixth. These variations cannot be observed with RM that estimated a heritability of 0.06. Values of 0.05 in the first calving until 0.07 in the tenth were estimated with ARM. Genetic correlations among DO for different parities were close to unity. Conclusions: changes of the estimated heritability for DO through the productive life of a female can be observed with ARM. The heritability estimates were low and did not differ from the results reported in other beef cattle breeds. Keywords: beef cattle, fertility, genetic correlations, heritability, post-partum interval. Resumen Antecedentes: en Cuba existe poca informacion relacionada con los componentes geneticos del periodo posparto en bovinos para carne. Objetivo: comparar los estimados de parametros geneticos de los dias abiertos (DO) obtenidos con tres modelos en ganado Charolais de Cuba. Metodos: los datos del control reproductivo individual de vacas Charolais de 17 hatos en dos empresas de Cuba fueron analizados. La muestra estuvo conformada por 16.891 partos de 4.593 vacas, hijas de 190 padres y 2.770 madres. Fueron considerados hasta 10 partos por hembras que ocurrieron entre 1981 y 2005. Se utilizo el programa WOMBAT para la estimacion de componentes de varianza. Se aplicaron tres modelos; un modelo univariado (UM) para cada parto independiente hasta el sexto parto; un modelo de repetibilidad (RM) con todos los partos; y un modelo de regresion aleatoria (ARM) tomando el numero del parto como variable independiente. Resultados: la media general de DO fue de 171 ± 93 dias. La tendencia del valor promedio para DO en cada parto fue decreciente desde el primero al decimo, con un comportamiento estacional alrededor de 155 dias entre el cuarto y el octavo parto. La heredabilidad de DO estimada por UM fue variable con valores de 0,03 en el primer parto y 0,06 en el sexto. Estas variaciones no pueden ser observadas con el RM que estimo una heredabilidad de 0,06. Valores de 0,05 en el primer parto hasta 0,07 en el decimo fueron estimados con el ARM. Las correlaciones geneticas entre DO para los diferentes partos fueron cercanos a la unidad. Conclusiones: los cambios de la heredabilidad estimada para DO a traves de la vida productiva de una hembra pueden ser observados con los ARM. Los estimados de heredabilidad fueron bajos y no difiere de los resultados reportados en otras razas de ganado bovino para carne. Palabras clave: bovinos para carne, correlaciones geneticas, fertilidad, heredabilidad, intervalo post-parto. Resumo Antecedentes: em Cuba ha pouca informacao sobre os componentes geneticos do periodo pos-parto em bovinos de corte. Objetivo: comparar as estimativas de parâmetros geneticos de dias vazios (DO) obtidos com os tres modelos em bovinos Charoles de Cuba. Metodos: os dados de controle reprodutivo individual de bovinos Charoles de 17 rebanhos em duas empresas de Cuba foram analisados. A amostra consistiu de 16.891 partos de 4.593 vacas, filhas de 190 touros e 2.770 matrizes. Ate 10 partos foram considerados por femea que ocorreram entre 1981 e 2005. O programa WOMBAT foi utilizado para estimar os componentes da variância. Tres modelos foram aplicados; um modelo univariado (UM) para cada paridade separado ate o sexto parto; um modelo de repetibilidade (RM) com todas as paricoes; e um modelo de regressao aleatoria (ARM), tendo o numero de partos como uma variavel independente. Resultados: a media geral foi de 171 ± 93 dias. A tendencia do valor medio para o DO em cada parto foi diminuindo desde o primeiro ate o decimo parto com um desempenho sazonal em torno de 155 dias entre o quarto e oitavo parto. A herdabilidade estimada para DO pela UM foi variavel com valores de 0,03 no primeiro parto e 0,06 no sexto. Essas variacoes nao podem ser observadas com RM que estimou uma herdabilidade de 0,06. Os valores de 0,05 no primeiro parto ate 0,07 no decimo foram estimados com ARM. As correlacoes geneticas entre DO para diferentes partos foram proximas da unidade. Conclusoes: alteracoes da herdabilidade estimada para DO durante a vida produtiva de uma femea pode ser observado com ARM. As estimativas de herdabilidade foram baixas e nao diferiram entre os resultados apresentados em outras racas de gado de corte. Palavras chave: bovino de corte, correlacao genetica, fertilidade, herdabilidade, intervalo pos-parto.