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This study analyzes the evolution of the population structure and genetic diversity of Braford cattle in South America from 1949 to 2019 to suggest effective strategies for breeding in the future. The percentage of bulls historically increased. The average generational interval decreased to 11.78 years for the current population. Average inbreeding (F) and coancestry (C) are low and show a historically increasing trend (0.001% to 0.002%, respectively). The degree of nonrandom mating (α) increased from -0.0001 to 0.0001 denoting a change in the trend to mate similar individuals. The average relatedness coefficient (ΔR) increased in the current period from 0.002% to 0.004%. A single ancestor explained 4.55% to 7.22% of the population's gene pool. While the effective population size based on the individual inbreeding rate (NeFi) was 462.963, when based on the individual coancestry rate (NeCi), it was 420.168. Genetic diversity loss is small and mainly ascribed to bottlenecks (0.12%) and to unequal contributions of the founders (0.02%). Even if adequate levels of diversity can be found, practices that consider the overuse of individual bulls (conditioned by nature or not), could lead to a long-term reduction in diversity. The present results permit tailoring genetic management strategies that are perfectly adapted to the needs that the population demands internationally.

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BACKGROUND: Genetic resistance in cattle is considered a suitable way to control tick burden and its consequent losses for livestock production. Exploring tick-resistant (R) and tick-susceptible (S) hosts, we investigated the genetic mechanisms underlying the variation of Braford resistance to tick infestation. Skin biopsies from four-times-artificially infested R (n = 20) and S (n = 19) hosts, obtained before the first and 24 h after the fourth tick infestation were submitted to RNA-Sequencing. Differential gene expression, functional enrichment, and network analysis were performed to identify genetic pathways and transcription factors (TFs) affecting host resistance. RESULTS: Intergroup comparisons of hosts before (Rpre vs. Spre) and after (Rpost vs. Spost) tick infestation found 51 differentially expressed genes (DEGs), of which almost all presented high variation (TopDEGs), and 38 were redundant genes. Gene expression was consistently different between R and S hosts, suggesting the existence of specific anti-tick mechanisms. In the intragroup comparisons, Rpost vs. Rpre and Spost vs. Spre, we found more than two thousand DEGs in response to tick infestation in both resistance groups. Redundant and non-redundant TopDEGs with potential anti-tick functions suggested a role in the development of different levels of resistance within the same breed. Leukocyte chemotaxis was over-represented in both hosts, whereas skin degradation and remodeling were only found in TopDEGs from R hosts. Also, these genes indicated the participation of cytokines, such as IL6 and IL22, and the activation of Wingless (WNT)-signaling pathway. A central gene of this pathway, WNT7A, was consistently modulated when hosts were compared. Moreover, the findings based on a genome-wide association study (GWAS) corroborate the prediction of the WNT-signaling pathway as a candidate mechanism of resistance. The regulation of immune response was the most relevant pathway predicted for S hosts. Members of Ap1 and NF-kB families were the most relevant TFs predicted for R and S, respectively. CONCLUSION: This work provides indications of genetic mechanisms presented by Braford cattle with different levels of resistance in response to tick infestation, contributing to the search of candidate genes for tick resistance in bovine.

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Background: The mechanisms of testicular thermoregulation may influence the blood flow provided by the testicularartery, where the proper blood supply to the testicle is crucial for promotingspermatogenesis and reproductive functionin bulls. The size and shape of the testicles are determined by genetic mechanisms and environmental effects. A betterunderstanding of the relationships between the anatomical characteristics of the testicles and scrotum can support a betterreproductive assessment. The purpose of the current study was to evaluate the testicular temperature of different scrotalshapes using infrared thermography in bulls.Materials, Methods & Results: We evaluated 132 Braford bulls with an average age of 24 months. The evaluation of breeding bull semen was performed prior to the beginning of the experiment. Then, animals were selected on the basis of the sizeof their testes, which was determined by dividing the average width by the average length. The scrotal circumference wasmeasured with a millimeter tape positioned around the largest circumference. Testicular and ocular temperature measurementsand analysis were conducted using an infrared thermal camera, Flir T440 with emissivity of 0.98 and thermal sensitivity of0.05°C. Testicular scrotum temperature and testicular shape were analyzed with one-way ANOVA using Minitab 16, andvalues of P < 0.05 were considered statistically significant. We observed that 67.42% of testicle shapes were long-oval,and 32.58% were long-moderate. The testicular temperature was higher in bulls with the long-moderate shape comparedto those with the long-oval shape (P < 0.05). The mean length was higher in long-moderate shaped testicles compared tothose of the long-oval shape (P < 0.01). There was no significant differences...(AU)

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Background: The mechanisms of testicular thermoregulation may influence the blood flow provided by the testicularartery, where the proper blood supply to the testicle is crucial for promotingspermatogenesis and reproductive functionin bulls. The size and shape of the testicles are determined by genetic mechanisms and environmental effects. A betterunderstanding of the relationships between the anatomical characteristics of the testicles and scrotum can support a betterreproductive assessment. The purpose of the current study was to evaluate the testicular temperature of different scrotalshapes using infrared thermography in bulls.Materials, Methods & Results: We evaluated 132 Braford bulls with an average age of 24 months. The evaluation of breeding bull semen was performed prior to the beginning of the experiment. Then, animals were selected on the basis of the sizeof their testes, which was determined by dividing the average width by the average length. The scrotal circumference wasmeasured with a millimeter tape positioned around the largest circumference. Testicular and ocular temperature measurementsand analysis were conducted using an infrared thermal camera, Flir T440 with emissivity of 0.98 and thermal sensitivity of0.05°C. Testicular scrotum temperature and testicular shape were analyzed with one-way ANOVA using Minitab 16, andvalues of P < 0.05 were considered statistically significant. We observed that 67.42% of testicle shapes were long-oval,and 32.58% were long-moderate. The testicular temperature was higher in bulls with the long-moderate shape comparedto those with the long-oval shape (P < 0.05). The mean length was higher in long-moderate shaped testicles compared tothose of the long-oval shape (P < 0.01). There was no significant differences...

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This study emphasized the importance of using candidate genes in predicting semen quality in bulls that can be used in cow-calf production. The aim of this study was to evaluate some candidate genes related to reproductive traits in Braford and Hereford bulls. All bulls (n=188) were submitted to breeding soundness evaluations at 24, 28, 32, and 36 months of age. The microsatellite markers ILSTS002 and BMS3004 associated with the luteinizing hormone-β (LHβ) gene, IDVGA-51 to leptin (LEP) gene,HEL5 and AFZ1 within the IGF-IR gene, and two SNP markers (LHR and FSHR) associated with the LHR and FSHR genes, respectively, were evaluated by the amplification of DNA products. The variation in the IDVGA-51 allele 177-185 showed polymorphic information content (PIC) associated with sperm motility and vigor traits in Hereford bulls. Hereford animals showed PIC of 0.36 to 0.75% along with expected heterozygosity (H) of 0.49 to 0.78%. Braford bulls that indicated the ILSTS002 allele 137-175 and AFZ1 allele 113-119 showed PIC associated with major and minor defects, respectively. The PIC ranged from 0.28 to 0.78%, with an expected H of 0.35 to 0.81%. AFZ1 allele 121-127 had the highest minor defects and ILSTS002 allele 125-135 showed the highest major defects from ejaculated semenin Braford bulls. In addition, IDVGA-51 allele 175 showed lower motility and vigor in Hereford bulls.The markers AFZ1 (IGF-IR) and ILSTS002 (LHβ) in Braford and IDVGA-51 (LEP) in Hereford bulls were effective in verifying the reproductive traits of the bulls.(AU)

Este estudo enfatizou a importância do uso de genes candidatos na predição da qualidade do sêmen em touros que podem ser utilizados na produção de bezerros. O objetivo deste estudo foi avaliar alguns genes candidatos relacionados a traços reprodutivos em touros de Braford e Hereford. Todos os touros (n = 188) foram submetidos a avaliações reprodutivas aos 24, 28, 32 e 36 meses de idade. Os marcadores microsatélites ILSTS002 e BMS3004 associados ao gene hormônio luteinizante-β (LHβ), o IDVGA-51 associado ao gene Leptina (LEP), o HEL5 e AFZ1 ao gene IGF-IR e dois marcadores SNP (LHR e FSHR) relacionados ao LHR e FSHR, respectivamente, foram avaliados pela amplificação de produtos de DNA. A variação no alelo IDVGA-51 177-185 mostrou conteúdo de informação polimórfica (PIC) associada à motilidade espermática e características de vigor nos touros de Hereford. Os animais Hereford apresentaram PIC de 0,36 a 0,75%, juntamente com heterozigosidade esperada (H) de 0,49 a 0,78%. Os touros Braford que indicaram o alelo ILSTS002 137-175 e o alelo AFZ1 113-119 mostraram PIC associados a defeitos maiores e menores, respectivamente. O PIC variou de 0,28 a 0,78% com um H esperado de 0,35 a 0,81%. O alelo AFZ1 121-127 teve os defeitos menores mais altos, enquanto, o alelo ILSTS002 125-135 mostrou altos defeitos maiores do sêmen ejaculado em Braford. Além disso, o alelo IDVGA-51 175 mostrou baixa motilidade e vigor nos touros Hereford. Os marcadores AFZ1 (IGF-IR) e ILSTS002 (LHβ) em Braford e IDVGA-51 (LEP) no Hereford foram efetivos na verificação dos traços reprodutivos dos touros.(AU)

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This study emphasized the importance of using candidate genes in predicting semen quality in bulls that can be used in cow-calf production. The aim of this study was to evaluate some candidate genes related to reproductive traits in Braford and Hereford bulls. All bulls (n=188) were submitted to breeding soundness evaluations at 24, 28, 32, and 36 months of age. The microsatellite markers ILSTS002 and BMS3004 associated with the luteinizing hormone-β (LHβ) gene, IDVGA-51 to leptin (LEP) gene,HEL5 and AFZ1 within the IGF-IR gene, and two SNP markers (LHR and FSHR) associated with the LHR and FSHR genes, respectively, were evaluated by the amplification of DNA products. The variation in the IDVGA-51 allele 177-185 showed polymorphic information content (PIC) associated with sperm motility and vigor traits in Hereford bulls. Hereford animals showed PIC of 0.36 to 0.75% along with expected heterozygosity (H) of 0.49 to 0.78%. Braford bulls that indicated the ILSTS002 allele 137-175 and AFZ1 allele 113-119 showed PIC associated with major and minor defects, respectively. The PIC ranged from 0.28 to 0.78%, with an expected H of 0.35 to 0.81%. AFZ1 allele 121-127 had the highest minor defects and ILSTS002 allele 125-135 showed the highest major defects from ejaculated semenin Braford bulls. In addition, IDVGA-51 allele 175 showed lower motility and vigor in Hereford bulls.The markers AFZ1 (IGF-IR) and ILSTS002 (LHβ) in Braford and IDVGA-51 (LEP) in Hereford bulls were effective in verifying the reproductive traits of the bulls.

Este estudo enfatizou a importância do uso de genes candidatos na predição da qualidade do sêmen em touros que podem ser utilizados na produção de bezerros. O objetivo deste estudo foi avaliar alguns genes candidatos relacionados a traços reprodutivos em touros de Braford e Hereford. Todos os touros (n = 188) foram submetidos a avaliações reprodutivas aos 24, 28, 32 e 36 meses de idade. Os marcadores microsatélites ILSTS002 e BMS3004 associados ao gene hormônio luteinizante-β (LHβ), o IDVGA-51 associado ao gene Leptina (LEP), o HEL5 e AFZ1 ao gene IGF-IR e dois marcadores SNP (LHR e FSHR) relacionados ao LHR e FSHR, respectivamente, foram avaliados pela amplificação de produtos de DNA. A variação no alelo IDVGA-51 177-185 mostrou conteúdo de informação polimórfica (PIC) associada à motilidade espermática e características de vigor nos touros de Hereford. Os animais Hereford apresentaram PIC de 0,36 a 0,75%, juntamente com heterozigosidade esperada (H) de 0,49 a 0,78%. Os touros Braford que indicaram o alelo ILSTS002 137-175 e o alelo AFZ1 113-119 mostraram PIC associados a defeitos maiores e menores, respectivamente. O PIC variou de 0,28 a 0,78% com um H esperado de 0,35 a 0,81%. O alelo AFZ1 121-127 teve os defeitos menores mais altos, enquanto, o alelo ILSTS002 125-135 mostrou altos defeitos maiores do sêmen ejaculado em Braford. Além disso, o alelo IDVGA-51 175 mostrou baixa motilidade e vigor nos touros Hereford. Os marcadores AFZ1 (IGF-IR) e ILSTS002 (LHβ) em Braford e IDVGA-51 (LEP) no Hereford foram efetivos na verificação dos traços reprodutivos dos touros.

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This study aimed to verify the influence of bovine genetic resistance on biological traits of the Rhipicephalus (Boophilus) microplus tick. Genetic resistance or susceptibility was determined according to breeding values for tick counts, predicted using a dataset of 9007 Hereford and Braford (Hereford×Zebu) bovines naturally infested and raised under extensive production systems in southern Brazil. From a total of 974 Braford heifers born in 2008, 20 were classified as genetically tick-resistant and 20 classified as genetically tick-susceptible, and used to obtain the ticks samples used in this study. The 40 heifers were exposed to four subsequent artificial infestations with approximately 20,000 larvae at 14-day intervals. From the 19th to 23rd day of each infestation tick counts were performed on the left body side of the heifers. Engorged ticks were manually collected on the day of highest observed burden after each infestation. Tick counts on susceptible heifers were 5.5, 10.5, 11.1 and 6.9 times larger than on resistant heifers, respectively, after the first, second, third and fourth artificial infestations. In the third infestation, ticks from resistant heifers showed lower egg production index (P<0.0001) than ticks from susceptible heifers. In the fourth infestation, ticks from susceptible group showed higher egg mass weight (P<0.05) and nutrient index (P<0.0001) than ticks from resistant heifers. Tick initial weights showed a positive association with egg production index in susceptible heifers (P<0.05) and a negative association in the resistant group (P<0.05), suggesting a host defense mechanism that reduces the conversion efficiency of ingested blood to eggs in engorged ticks from resistant cattle. This shows that bovine genetic tick resistance, in addition to affecting the number of ticks carried by the animals, also affected the egg mass weight, egg production and nutrient indexes of ticks. The results of the present study imply that the selection of resistant animals could be used as a strategic tool for tick control in production systems, reducing infestation levels on cattle and environment.

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Este trabalho foi desenvolvido com o objetivo de estudar os efeitos da elevação da altura de corte da silagem de milho de 16 para 46 cm, associados aos níveis de 16% ou 30% de concentrado sobre o total da matéria seca oferecida, sobre as características da carcaça de bezerros. Utilizaram-se 24 bezerros Braford, desmamados aos três meses de idade e terminados em confinamento dos sete aos doze meses de idade, quando foram abatidos. Não se observou interação entre altura de corte e nível de concentrado. As variáveis percentagens dos cortes comerciais da carcaça, as medidas métricas da carcaça, bem como as percentagens de osso, de músculo e de gordura e relações entre os tecidos da carcaça não foram afetadas pela altura de colheita da silagem ou pelo nível de concentrado usado nas dietas. Alem disso, a carne de animais alimentados com nível mais baixo de concentrado teve menor perda durante o descongelamento (5,05% vs 8,03%), resultando em maior suculência (7,14 vs 6,74 pontos), embora a carne apresentasse coloração mais escura que a carne dos outros novilhos (3,17 vs 4,00 pontos). Na comparação entre as alturas de colheita da silagem, a maior suculência foi observada na carne de animais alimentados com silagem colhida a 16 cm do solo (7,18 vs 6,69 pontos), cuja carne teve menor perda durante o descongelamento (4,70 vs 8,38%) e durante a cocção (17,11 vs 22,33%).(AU)

This work was conducted with the objective of verifying the effects of increasing the corn silage harvest height from 16 to 46 cm, associated to 16 or 30% of concentrate level on total dry matter offered, on carcass and meat characteristics of young steers. Twenty-four Braford calves, weaned at three months of age, were finished in feedlot from seven to twelve months, when they were slaughtered. The commercial carcass cuts, metric carcass measurements, such as the bone, muscle and fat percentages and carcass tissues ratios were not affected by the silage harvest height and diet concentrate level used. On the other hand, meat of steers fed with low concentrate level had lower thawing loss (5.05 vs. 8.03%) resulting in higher juiciness (7.14 vs. 6.74 points), although the meat showed darker coloration than the meat of the other steers (3.17 vs. 4.00 points). The comparison between harvest heights showed that meat of steers fed with silage harvested at 16 cm from the soil had higher juiciness (7.18 vs. 6.69 points), as the result showed lower thawing loss (4.70 vs. 8.38%) and lower cooking loss (17.11 vs. 22.33%).(AU)

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Este trabalho foi desenvolvido com o objetivo de estudar os efeitos da elevação da altura de corte da silagem de milho de 16 para 46 cm, associados aos níveis de 16% ou 30% de concentrado sobre o total da matéria seca oferecida, sobre as características da carcaça de bezerros. Utilizaram-se 24 bezerros Braford, desmamados aos três meses de idade e terminados em confinamento dos sete aos doze meses de idade, quando foram abatidos. Não se observou interação entre altura de corte e nível de concentrado. As variáveis percentagens dos cortes comerciais da carcaça, as medidas métricas da carcaça, bem como as percentagens de osso, de músculo e de gordura e relações entre os tecidos da carcaça não foram afetadas pela altura de colheita da silagem ou pelo nível de concentrado usado nas dietas. Alem disso, a carne de animais alimentados com nível mais baixo de concentrado teve menor perda durante o descongelamento (5,05% vs 8,03%), resultando em maior suculência (7,14 vs 6,74 pontos), embora a carne apresentasse coloração mais escura que a carne dos outros novilhos (3,17 vs 4,00 pontos). Na comparação entre as alturas de colheita da silagem, a maior suculência foi observada na carne de animais alimentados com silagem colhida a 16 cm do solo (7,18 vs 6,69 pontos), cuja carne teve menor perda durante o descongelamento (4,70 vs 8,38%) e durante a cocção (17,11 vs 22,33%).

This work was conducted with the objective of verifying the effects of increasing the corn silage harvest height from 16 to 46 cm, associated to 16 or 30% of concentrate level on total dry matter offered, on carcass and meat characteristics of young steers. Twenty-four Braford calves, weaned at three months of age, were finished in feedlot from seven to twelve months, when they were slaughtered. The commercial carcass cuts, metric carcass measurements, such as the bone, muscle and fat percentages and carcass tissues ratios were not affected by the silage harvest height and diet concentrate level used. On the other hand, meat of steers fed with low concentrate level had lower thawing loss (5.05 vs. 8.03%) resulting in higher juiciness (7.14 vs. 6.74 points), although the meat showed darker coloration than the meat of the other steers (3.17 vs. 4.00 points). The comparison between harvest heights showed that meat of steers fed with silage harvested at 16 cm from the soil had higher juiciness (7.18 vs. 6.69 points), as the result showed lower thawing loss (4.70 vs. 8.38%) and lower cooking loss (17.11 vs. 22.33%).

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Se aplicó un panel de nueve marcadores microsatélites para estructurar la genealogía de un hato de ganado Braford manejado bajo empadre múltiple y destinado a pié de cría, para evaluar las repercusiones de la adecuada asignación de progenitores, así como las implicaciones en su mejoramiento genético. Se logró la asignación de paternidad en el 100% de la progenie, mientras que en los ensayos de verificación de maternidad se estimó un porcentaje de error de asignación de aproximadamente 90%. Los resultados encontrados apoyan el uso de la asignación de paternidad para verificar la estructura genealógica (paternidad y maternidad) de hatos cuya certeza en el pedigrí es crítica para el mejoramiento genético de su raza, y en donde el sistema de manejo extensivo y empadre múltiple limitan el registro adecuado de la progenie al momento del parto.

To assess the implications of parentage assignation on herds-genetic improvement nine microsatellite markers were used in order to structure the genealogy of a multisired Braford herd. All progeny (100%) had satisfactory paternity assignment, conversely the maternity verification analysis showed assignation errors up to 90%. Our results support the use of molecular tools to verify the pedigree structure in those herds with management systems that limit the proper registration of progeny at calving.

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Este trabalho teve como objetivo estudar os fatores corporais envolvidos na variação do rendimento de carcaça em machos castrados ou fêmeas não prenhes, abatidos aos quatorze meses de idade. Os animais foram terminados com suplementação energética sobre pastagem cultivada. Utilizaram-se doze animais de cada sexo, mestiços Nelore (3/8) x Hereford (5/8), contemporâneos do mesmo rebanho. Os pesos de fazenda, de frigorífico e de carcaça quente foram superiores nos machos, sendo de 365,8; 350,4 e 203,4 kg, respectivamente, enquanto as fêmeas apresentaram 310,3; 294,5; e 168,6 kg, citados na mesma ordem. Bovinos machos também apresentaram maiores rendimentos de carcaça quente em relação ao peso de fazenda (55,6 vs 54,4%) e em relação ao peso de frigorífico (58,1 vs 57,2%) do que as fêmeas. O menor rendimento de carcaça das fêmeas deveu-se ao maior percentual de couro (9,03 vs 7,96%), gordura inguinal, junto ao úbere das fêmeas ou à capadura dos machos (1,02 vs 0,67%), trato digestivo cheio (19,35% vs 16,84%), rúmen mais retículo vazios (2,34 vs 1,91%) e intestino vazio (2,54% vs 2,11%). Não houve diferença significativa entre sexos nos percentuais de coração, fígado, pulmões, rins e baço, sendo, respectivamente, 0,40%, 0,93%, 1,01%, 0,22% e 0,35% nos machos e 0,41%, 0,98%, 1,02%, 0,22% e 0,30% nas fêmeas, citados na mesma ordem.(AU)

The objective of the experiment was to study the body factors related to the variation of dressing percentage in castrated males or non-pregnant females, slaughtered at fourteen months of age. The animals were finished with energetic supplementation on cultivated pasture. Twelve contemporary animals of each sex were used, all crossbred Nellore (3/8) x Hereford (5/8) from the same herd. Farm live weight, slaughterhouse live weight and hot carcass weight were superior in males, being 365.8; 350.4 and 203.4 kg, respectively, while the females showed 310.3; 294.5; and 168.6 kg, in the same order. Males also showed higher hot carcass dressing percentage in relation to farm live weight (55.6 vs 54.4%) and in relation to slaughterhouse weight (58.1 vs 57.2%) than females. The lower female dressing percentage was a result of the higher hide (9.03 vs 7.96%), inguinal fat in the udder of heifers or cod fat of steers (1.02 vs .67%), full digestive tract (19.35 vs 16.84%), empty rumen plus reticulum (2.34 vs 1.91%) and empty intestine (2.54 vs 2.11%) percentages. There was no significant difference between sexes in heart, liver, lungs, kidneys and spleen percentages, being, respectively, 0.40, 0.93, 1.01, 0.22 and 0.35% in males and 0.41, 0.98, 1.02, 0.22 and 0.30% in females, cited in the same order.(AU)

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Este trabalho teve como objetivo estudar os fatores corporais envolvidos na variação do rendimento de carcaça em machos castrados ou fêmeas não prenhes, abatidos aos quatorze meses de idade. Os animais foram terminados com suplementação energética sobre pastagem cultivada. Utilizaram-se doze animais de cada sexo, mestiços Nelore (3/8) x Hereford (5/8), contemporâneos do mesmo rebanho. Os pesos de fazenda, de frigorífico e de carcaça quente foram superiores nos machos, sendo de 365,8; 350,4 e 203,4 kg, respectivamente, enquanto as fêmeas apresentaram 310,3; 294,5; e 168,6 kg, citados na mesma ordem. Bovinos machos também apresentaram maiores rendimentos de carcaça quente em relação ao peso de fazenda (55,6 vs 54,4%) e em relação ao peso de frigorífico (58,1 vs 57,2%) do que as fêmeas. O menor rendimento de carcaça das fêmeas deveu-se ao maior percentual de couro (9,03 vs 7,96%), gordura inguinal, junto ao úbere das fêmeas ou à capadura dos machos (1,02 vs 0,67%), trato digestivo cheio (19,35% vs 16,84%), rúmen mais retículo vazios (2,34 vs 1,91%) e intestino vazio (2,54% vs 2,11%). Não houve diferença significativa entre sexos nos percentuais de coração, fígado, pulmões, rins e baço, sendo, respectivamente, 0,40%, 0,93%, 1,01%, 0,22% e 0,35% nos machos e 0,41%, 0,98%, 1,02%, 0,22% e 0,30% nas fêmeas, citados na mesma ordem.

The objective of the experiment was to study the body factors related to the variation of dressing percentage in castrated males or non-pregnant females, slaughtered at fourteen months of age. The animals were finished with energetic supplementation on cultivated pasture. Twelve contemporary animals of each sex were used, all crossbred Nellore (3/8) x Hereford (5/8) from the same herd. Farm live weight, slaughterhouse live weight and hot carcass weight were superior in males, being 365.8; 350.4 and 203.4 kg, respectively, while the females showed 310.3; 294.5; and 168.6 kg, in the same order. Males also showed higher hot carcass dressing percentage in relation to farm live weight (55.6 vs 54.4%) and in relation to slaughterhouse weight (58.1 vs 57.2%) than females. The lower female dressing percentage was a result of the higher hide (9.03 vs 7.96%), inguinal fat in the udder of heifers or cod fat of steers (1.02 vs .67%), full digestive tract (19.35 vs 16.84%), empty rumen plus reticulum (2.34 vs 1.91%) and empty intestine (2.54 vs 2.11%) percentages. There was no significant difference between sexes in heart, liver, lungs, kidneys and spleen percentages, being, respectively, 0.40, 0.93, 1.01, 0.22 and 0.35% in males and 0.41, 0.98, 1.02, 0.22 and 0.30% in females, cited in the same order.

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O objetivo deste trabalho foi avaliar os efeitos do frame e da altura de garupa sobre o desempenho reprodutivo de novilhas de corte. Sessenta e uma novilhas Braford de 24 meses de idade, em boa condição corporal (CC4 em escala de 1-5) foram classificadas em dois grupos, altura de garupa (grupo Alto entre 129 a 135 cm e grupo Baixo entre 118 e 128 cm) e em dois grupos de frame (Maior entre 5.8 a 7.1 e Menor entre 3.5 e 5.7). As variáveis analisadas foram a frequência de novilhas cíclicas e gestantes e o peso pré-acasalamento. Não houve efeito significativo (P<0,05) do frame e altura de garupa sobre a freqüência de novilhas cíclicas e gestantes. O peso pré-acasalamento foi maior (P>0,05) no grupo Alto do que no grupo Baixo (359,4 ± 3,1 e 331,4 ± 3,5, respectivamente). Em um rebanho de novilhas Braford de 24 meses, pequenas variações na altura de garupa e frame não são capazes de afetar o desempenho reprodutivo das fêmeas. Mesmo havendo uma diferença superior a 25kg no início do acasalamento, as novilhas de diferentes tamanhos apresentaram desempenho reprodutivo igual(AU)

The objective of this study was evaluated the frame and hip height effects on reproductive performance in beef heifers. Sixty one twenty four months-old Braford heifers, in the same body condition score (BCS4 in a 1-5 scale) were allocated into two groups by hip height (Alto group between 129 a 135 cm and Baixo group between 118 e 128 cm) and into two groups by frame (Maior between 5.8 a 7.1 scores and Menor between 3.5 e 5.7 scores). The variables analyzed were heifers exhibited ovarian cyclicity and pregnancy frequency and prebreeding weight. There were no significant effect (P>0.05) of frame and hip height on heifers exhibited ovarian cyclicity and pregnancy frequency. The prebreeding weight was heavier (P<0.05) in the Alto group than in the Baixo group (359.4 ± 3.1 and 331.4 ± 3.5, respectively). In a 24 months-old Braford herd, small variation in hip height and frame do not affect the reproductive performance. Even with a 25 kg difference in the beginning of breeding season the heifers with different frame have same reproductive performance(AU)

Assuntos

RESUMO

O objetivo deste trabalho foi avaliar os efeitos do frame e da altura de garupa sobre o desempenho reprodutivo de novilhas de corte. Sessenta e uma novilhas Braford de 24 meses de idade, em boa condição corporal (CC4 em escala de 1-5) foram classificadas em dois grupos, altura de garupa (grupo Alto entre 129 a 135 cm e grupo Baixo entre 118 e 128 cm) e em dois grupos de frame (Maior entre 5.8 a 7.1 e Menor entre 3.5 e 5.7). As variáveis analisadas foram a frequência de novilhas cíclicas e gestantes e o peso pré-acasalamento. Não houve efeito significativo (P0,05) no grupo Alto do que no grupo Baixo (359,4 ± 3,1 e 331,4 ± 3,5, respectivamente). Em um rebanho de novilhas Braford de 24 meses, pequenas variações na altura de garupa e frame não são capazes de afetar o desempenho reprodutivo das fêmeas. Mesmo havendo uma diferença superior a 25kg no início do acasalamento, as novilhas de diferentes tamanhos apresentaram desempenho reprodutivo igual

The objective of this study was evaluated the frame and hip height effects on reproductive performance in beef heifers. Sixty one twenty four months-old Braford heifers, in the same body condition score (BCS4 in a 1-5 scale) were allocated into two groups by hip height (Alto group between 129 a 135 cm and Baixo group between 118 e 128 cm) and into two groups by frame (Maior between 5.8 a 7.1 scores and Menor between 3.5 e 5.7 scores). The variables analyzed were heifers exhibited ovarian cyclicity and pregnancy frequency and prebreeding weight. There were no significant effect (P>0.05) of frame and hip height on heifers exhibited ovarian cyclicity and pregnancy frequency. The prebreeding weight was heavier (P<0.05) in the Alto group than in the Baixo group (359.4 ± 3.1 and 331.4 ± 3.5, respectively). In a 24 months-old Braford herd, small variation in hip height and frame do not affect the reproductive performance. Even with a 25 kg difference in the beginning of breeding season the heifers with different frame have same reproductive performance

Assuntos

RESUMO

The experiment was conducted with the objective to evaluate the use of soybean meal centrifugeted (SMC) as substitution for soybean meal (SM) in the concentrate fraction of the diet of confined steer calves, being tested the following treatments: T1 - 100% of SM; T2 - 66% of SM + 34% of SMC; T3 - 34% of SM + 66% of SMC e T4 - 100% of SMC. Thirty-six steers no castrated Braford (5/8 Hereford 3/8 Nellore) calves with an age average of seven months and average live weight of 202kg, were used. The whole feedlot period was 168 days, divided in four periods of 42 days. The roughage:concentrate ratio was 60:40 for the first and second periods, 50:50 for the third period and 45:55 for the fourth period. No signification interaction was observed between substitution of level of the protein source and feedlot evaluation period for average daily dry matter intake (DMI), crude protein intake (CPI) and digestible energy intake (DEI), respectively, expressed per animal (DMID, CPID and DEID), per 100kg of live weight (DMIP, CPIP, DEIP) and per unit of metabolic weight (DMIM, CPIM and DEIM), for average daily weight gain (ADG), feed conversion (FC) and crude protein efficiency (CPE). The use of soybean meal centrifugeted with protein source as substitution partial or total of soybean meal in concentrate fraction of the diet feedlot steer calves, for young beef cattle production, did not affect (P>.05) of average dry matter intake, daily weight gain, feed conversion and crude protein efficiency.

Este experimento teve por objetivo avaliar a utilização do farelo de soja centrifugado (FSC) como substituto ao farelo de soja (FS) na fração concentrada da dieta de bezerros de corte em confinamento, sendo testados os seguintes tratamentos: T1 - 100% de FS; T2 - 66% de FS + 34% de FSC; T3 - 34% de FS + 66% de FSC; e T4 - 100% de FSC. Foram utilizados 36 bezerros machos da raça Braford, com idade média de sete meses e peso vivo médio inicial de 202kg. O confinamento compreendeu 168 dias de avaliação, sendo dividido em quatro períodos de 42 dias cada. A relação volumoso:concentrado foi de 60:40 para o 1° e 2° períodos, de 50:50 para o 3° período e de 45:55 para o 4° período. Não houve interação (P>0,05) entre nível de substituição da fonte protéica e período de avaliação em confinamento para os parâmetros relativos aos consumos diários de matéria seca (CMS), proteína bruta (CPB) e energia digestível (CED), respectivamente, expressos em kg animal-1 (CMSD e CPBD) ou Mcal/animal (CEDD), por 100kg de peso vivo (CMSP, CPBP e CEDP) e por unidade de tamanho metabólico (CMSM, CPBM e CEDM), ao ganho de peso médio diário (GMD) e a eficiência da transformação da matéria seca consumida (CA) e da proteína bruta consumida (EPB) em ganho de peso. A utilização de farelo de soja centrifugado como fonte protéica em substituição parcial ou integral ao farelo de soja na fração concentrada da dieta alimentar de bezerros de corte, visando à produção do superprecoce, não comprometeu (P>0,05) o consumo de alimentos, o ganho de peso médio diário e a eficiência da transformação da matéria seca consumida e da proteína bruta consumida em ganho de peso.

RESUMO

The experiment was conducted with the objective to evaluate the use of soybean meal centrifugeted (SMC) as substitution for soybean meal (SM) in the concentrate fraction of the diet of confined steer calves, being tested the following treatments: T1 - 100% of SM; T2 - 66% of SM + 34% of SMC; T3 - 34% of SM + 66% of SMC e T4 - 100% of SMC. Thirty-six steers no castrated Braford (5/8 Hereford 3/8 Nellore) calves with an age average of seven months and average live weight of 202kg, were used. The whole feedlot period was 168 days, divided in four periods of 42 days. The roughage:concentrate ratio was 60:40 for the first and second periods, 50:50 for the third period and 45:55 for the fourth period. No signification interaction was observed between substitution of level of the protein source and feedlot evaluation period for average daily dry matter intake (DMI), crude protein intake (CPI) and digestible energy intake (DEI), respectively, expressed per animal (DMID, CPID and DEID), per 100kg of live weight (DMIP, CPIP, DEIP) and per unit of metabolic weight (DMIM, CPIM and DEIM), for average daily weight gain (ADG), feed conversion (FC) and crude protein efficiency (CPE). The use of soybean meal centrifugeted with protein source as substitution partial or total of soybean meal in concentrate fraction of the diet feedlot steer calves, for young beef cattle production, did not affect (P>.05) of average dry matter intake, daily weight gain, feed conversion and crude protein efficiency.

Este experimento teve por objetivo avaliar a utilização do farelo de soja centrifugado (FSC) como substituto ao farelo de soja (FS) na fração concentrada da dieta de bezerros de corte em confinamento, sendo testados os seguintes tratamentos: T1 - 100% de FS; T2 - 66% de FS + 34% de FSC; T3 - 34% de FS + 66% de FSC; e T4 - 100% de FSC. Foram utilizados 36 bezerros machos da raça Braford, com idade média de sete meses e peso vivo médio inicial de 202kg. O confinamento compreendeu 168 dias de avaliação, sendo dividido em quatro períodos de 42 dias cada. A relação volumoso:concentrado foi de 60:40 para o 1° e 2° períodos, de 50:50 para o 3° período e de 45:55 para o 4° período. Não houve interação (P>0,05) entre nível de substituição da fonte protéica e período de avaliação em confinamento para os parâmetros relativos aos consumos diários de matéria seca (CMS), proteína bruta (CPB) e energia digestível (CED), respectivamente, expressos em kg animal-1 (CMSD e CPBD) ou Mcal/animal (CEDD), por 100kg de peso vivo (CMSP, CPBP e CEDP) e por unidade de tamanho metabólico (CMSM, CPBM e CEDM), ao ganho de peso médio diário (GMD) e a eficiência da transformação da matéria seca consumida (CA) e da proteína bruta consumida (EPB) em ganho de peso. A utilização de farelo de soja centrifugado como fonte protéica em substituição parcial ou integral ao farelo de soja na fração concentrada da dieta alimentar de bezerros de corte, visando à produção do superprecoce, não comprometeu (P>0,05) o consumo de alimentos, o ganho de peso médio diário e a eficiência da transformação da matéria seca consumida e da proteína bruta consumida em ganho de peso.