Assessment of sexual behavior of young rams of Santa Inês breed, with and without prior experience with females

The objective of the present work was to determine if prior sexual experience with females in oestrus influences the frequency of events related to sexual behavior and if it is possible to reduce duration of the test period from 10 to 5 min. Nineteen lambs born in 2007 in Espírito Santo State, Brazil, were separated by month of birth into two groups. Those of each group were subjected to a first libido test at 7 mo of age when they had no previous exposure to females since weaning (EXP1). The second test was realized at 11 mo, when the males already had prior experience with females in oestrus (EXP2). Comportments associated with the detection of heat were frequent in both tests, while those associated with courting were more frequent in EXP2. During the first 5 min of observation the behaviors of chasing, smelling, and licking were significantly more frequent than subsequently, while frequency of other characteristics didn’t differ between times of assessment. Body weight and age influenced sexual comportment, older and heavier males tending to mount the female and ejaculate more times. It can be concluded that young rams with prior experience exhibit greater stimulus to complete copulation and that 5 min can be time enough to evaluate their libido

Effect of nursing behaviour, sex of the calf, and parity order on milk production of buffaloes

Background: the allonursing effect on daily milk production (DMP) and total milk production (TMP) has been little explored. Objective: to evaluate the effect of nursing behaviour, sex of the calf and parity order (PO) on DMP and TMP of buffalo cows. Methods: thirty-five buffalo cows and their calves were evaluated. Observations were performed monthly (three consecutive days) from May to November. The nursing behavior was characterized as: 1) isolated filial nursing (IFN); 2) collective filial nursing (CFN), and 3) non-filial nursing (NFN). Cows were grouped into four categories to study the effects of nursing behavior on DMP and TMP: 1) non-permissive (NP); 2) filial permissive (FP); 3) filial and collective filial permissive (FCFP); and 4) filial, collective filial and non-filial permissive (FCFNFP). DMP was recorded three days per month and TMP was calculated as DMP*270 days of lactation. Results: sex of the calf and second and third PO had an effect on nursing behavior (p<0.05). DMP and TMP were significantly affected by calf sex and nursing behaviour (p<0.05). PO had no effect on DMP and TMP. Conclusion: our results suggest that nursing behaviour is associated with milk production in buffalo cows. Buffalo cows that accept all types of nursing behaviour had the highest DMP and TMP. Sex of the calf influenced nursing behaviour, DMP, and TMP, so that buffalo cows with male calves displayed more frequent allonursing behaviour and yielded more milk

Study of genetic varibility of reproductive traits in Nellore bulls

Heritabilities, were estimated of testicular traits, semen quality and libido in Nellore bulls. Records on 438 bulls registered from 1992 to 1997 were analyzed by single trait MTDFREML methodology using the animal model. The estimates obtained of heritability unadjusted and adjusted for body weight and the respective standard errors were: for scrotal circumference (0.81 ± 0.04 and 0.71 ± 0.07); testicular consistency (0.17 ± 0.09 and 0.17 ± 0.10); right testes length (0.42 ± 0.10 and 0.31 ± 0.11); left testes length (0.38 ± 0.10 and 0.30 ± 0.10); right testes width (0.78 ± 0.05 and 0.38 ± 0.12); left testes width (0.78 ± 0.05 and 0.34 ± 0.13); testicular volume (0.50 ± 0.09 and 0.30 ± 0.10); semen volume (0.20 ± 0.10 and 0.20 ± 0.10); sperm motility (0.15 ± 0.11 and 0.15±.11); sperm vigor (0.55 ± 0.10 and 0.54 ± 0.10); gross motility (0.07 ± 0.4 and 0.06 ± 0.4); major defects (0.59 ± 0.09 and 0.51 ± 0.11); minor defects (0.21 ±0.13 and 0.13 ± 0.11); total sperm defects (0.58 ± 0.09 and 0.48 ± 0.12) and libido (0.34 ± 0.10 and 0.19 ± 0.11)

Efeito de diferentes formas de cultivo na ação do óxido nítrico na maturação e na integridade da membrana plasmática de complexos cumulus-oócito em bovinos

The aim of the present study was to evaluate the influence of different forms of in vitro culture on the nitric oxide action in maturation and membrane integrity on bovine cumulus-oocyte complex. No significant effect was observed between different forms of culture (mineral oil vs plate; P &gt; 0.05), as much for membrane integrity as for expansion of the CC. However, it was observed that oocytes of the groups control and 10-3 M of SNP, cultivated in plate, had presented greater percentage of cell with maintenance of membrane integrity than same treatments cultivated in drop. The addition of 10-3 M of SNP showed an inhibitory effect on the expansion and membrane integrity of CC and oocytes in both, culture in drops under oil and plate (P < 0.05). The culture form did not intervene with the extrusion of the first polar corpuscle and the addition of 10-3 M of SNP inhibited this extrusion in the both systems (P < 0.05). There was a dose-response effect on the concentration of NO in the maturation medium in both types of cultivation (P < 0,05), and this was higher in the culture medium under oil, except when added 10-3 M of SNP, treatment in which there was no difference in the types of cultivation employed. (PO objetivo do presente estudo foi avaliar se diferentes formas de cultivo interferem no efeito do óxido nítrico (NO) sobre a maturação e a integridade da membrana plasmática do complexo cumulus-oócito de bovinos. Para tanto, realizou-se cultivo em gotas sob óleo mineral ou em placas de quatro poços com a adição de diferentes concentrações de nitroprussiato de sódio (SNP, doador de óxido nítrico). Não foi observada diferença (P &gt; 0,05) entre as formas de cultivo quando se avaliou a integridade de membrana plasmática e a expansão das células do cumulus (CC). Contudo, os oócitos dos grupos controle e os cultivados na presença de 10-3 M de SNP, ambos cultivados em placa, apresentaram maior porcentagem de membrana íntegra do que os mesmos tratamentos cultivados em óleo mineral (P &lt; 0,05). Observou-se que a adição de 10-3 M de SNP diminuiu o grau de expansão das CC e de integridade da membrana plasmática dos oócitos, tanto no cultivo em gota sob óleo quanto em placa, diferindo dos outros grupos (P &lt; 0,05). Semelhante à expansão, a forma de cultivo não interferiu na extrusão do primeiro corpúsculo polar, sendo que a adição de 10-3 M de SNP inibiu a extrusão em ambos os sistemas (P &lt; 0,05). Houve um efeito dose-resposta na concentração de NO no meio de maturação em ambos os tipos de cultivo (P &lt; 0,05), sendo que esta foi maior no meio de cultivo sob óleo, exceção feita quando se adicionou 10-3 M de SNP, tratamento no qual não houve diferença nos tipos de cultivo empregados. Estes dados mostram que o sistema de cultivo não interferiu na ação do NO na maturação in vitro de COC bovinos, mas interfere na integridade da membrana plasmática do oócito

GM 04. Scrotal measurements, weight, and semen quality in Nellore bulls

Field data on 215 Nellore bulls (92sires and 123 sons), born from 1989 to 1993, were analyzed using DFREML methodology under uni and bivariate animal models to estimate heritabilities, phenotypic and genetic correlation between testis measurements, body weights and semen characteristics. Heritability estimates for scrotal circumference, left and right testis length and width were, respectively, 0.87, 0.89, 0.89, 0.90 and 8.85. Heritability estimates for motility, volume and vigor were, respectively, 0.12, 0.10 and 0.59. Genetic correlation between all testis measurements were high (from 0.61 to unit). Genetic correlation between scrotal circumference and semen motility, volume and vigor were, respectively, 1.00, 0.00 and 0.69

Concentration of fecal corticosterone metabolites in dominant versus subordinate buffalo heifers

The objective of this work was to evaluate the concentration of fecal metabolites of corticosterone and to verify if there are differences between dominant and subordinate heifers. The feces of 18 buffalo heifers were collected in the estrous period, to quantify the corticosterone concentrations. The heifers were separated into three groups (G1, G2 and G3) and synchronized. The observations of the social and sexual behaviors were recorded and, from these results, the sociometric matrix was constructed to establish the social index and determine the hierarchic positions of the buffalo heifers as low, moderate and high. The fecal concentrations of corticosterone were higher in animals with high hierarchic position on day zero and describe alterations in the dominant females before synchronization, suggesting that there is an energy cost for the females in the highest position to be able to maintain their dominance status.Keywords: Estrus, hormones, social status, non-invasive techniqueAfrican Journal of Biotechnology, Vol 13(16), 1726-173

Association between BMP4 gene polymorphism and in vitro embryo production traits in Gyr cows

Background: candidate genes and their polymorphisms have been associated with traits of economic interest in cattle, representing an important strategy for genetic improvement of complex traits. Bone morphogenetic protein 4 (BMP4) is a member of the transforming growth factor beta (TGFβ) superfamily, which is involved with several events of embryonic, fetal, and adult development in vertebrates. Objective: the aim of this study was to evaluate the degree of association between polymorphism in the BMP4 gene (guanine for thymine- G>T, SNP rs109778173) and the performance of Gyr oocyte donors, including the rate of Cumulus-oophorus complex obtained in each session of follicular aspiration (OPU), embryo development, and pregnancy rates. Methods: DNA was extracted from hair follicles from 50 oocyte donors and genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Data from 212 OPU-IVP sessions was collected, and the following traits were associated with BMP4 polymorphism (SNP rs109778173): number and ratio of viable Cumulus-oophorus complexes; number of cleaved embryos at day 4 of culture; number of transferable embryos at day 7 of culture, and pregnancies on days 30 and 60 after embryo transfer. Results: the studied BMP4 polymorphism was significantly associated (p<0.01) with the number and ratio of viable cumulus-oocyte complexes, and the ratio of pregnancies at 30 days. Conclusion: the GT genotype (SNP rs109778173) was associated with inferior performance regarding OPU-IVP traits. This finding suggests possible genetic effects of BMP4 on performance of Gyr oocyte donors. Studies are needed on the BMP4 gene regarding subsequent changes in embryonic development of said mutation

Relationship of serum testosterone, sperm production, and testis traits with fertility of Mangalarga Marchador stallions

Abstract Background: Assessing breeding soundness is important to predict the potential fertility of stallions. Objective: To investigate the association of testis traits, total number of spermatozoa, and testosterone with fertility of Mangalarga Marchador breed stallions. Methods: The traits measured were testicular length, width and height, right and left testicular volume and total testicular volume. We also evaluated the total number of spermatozoa (TNS), serum testosterone concentration and fertility of stallions (by embryo recovery from donor mares) in the breeding and non-breeding seasons during 1 year. Analysis of variance was performed to verify the effects of age category (AC; young/adult) and reproductive season on the traits. Correlations and repeatability of the traits were also calculated. Results: The AC did not influence testis traits (p>0.05). Reproduction season affected left testicular length, left testicular height, right testicular width and height (p0.05). We observed strong correlations between all testicular measurements and testicular volume (0.53 to 0.75), medium correlation between TNS and testis volume (0.32), and low correlation between testosterone and testis traits (0.20). Repeatability of the characteristics of left and right testis was medium to high (0.22 to 0.78). Embryo recovery rate was 60% and its correlation with TNS was 0.44. Conclusion: Testis size evaluation is recommended over the evaluation of serum testosterone concentration to predict sperm output. Sperm output (TNS) is a good predictor of stallion fertility

Alterações nos parâmetros hematológico durante a gestação e no pós-parto de cabras da raça Saanen criadas no sul do Espírito Santo

Resumo: O objetivo deste estudo foi avaliar o perfil hematológico de cabras da raça Saanen em diferentes fases da gestação e no pós-parto. Para sua realização foram utilizadas 24 cabras gestantes e 10 não gestantes da raça Saanen, criadas em condições intensivas no município de Alegre, Espírito Santo. As amostras foram coletadas dos 60 aos 135 dias de gestação, com intervalos de 15 dias entre as coletas. Após a parição foram realizadas mais duas coletas, também com intervalos de 15 dias. As amostras de sangue coletadas foram refrigeradas até a chegada ao laboratório, onde foi realizado o eritrograma e a leucometria global em analisador automático e as contagens diferenciais em esfregaço sanguíneo. Após análise dos resultados pode-se observar que, nas cabras avaliadas, houve influência do período de gestação, do pós-parto e da ordem de parto sobre os valores do eritrograma. Todos parâmetros avaliados, exceto VGM, diminuiram com o avançar da gestação até os quinze dias pós-parto, sendo que as maiores alterações ocorreram no final da gestação. A leucometria global (LG) e específica também apresentaram diferenças significativas de acordo com o estado fisiológicos das fêmeas. Os valores médios de LG foram de 10.579 a 15.836 leucócitos/mm3. Fêmeas não gestantes apresentaram maiores valores de LG, diminuindo com a gestação até os 15 dias do pós-parto. Trinta dias pós-parto o valor de LG aumentou, assemelhando-se aos valores das cabras não gestantes. Os valores absolutos de neutrófilos segmentados seguiram a mesma tendência da LG. A quantidade de linfócitos apresentou diminuição a partir dos 120 dias de gestação, aumentando a partir dos trinta dias pós-parto. A quantidade de eosinófilos não sofreu alteração de acordo com o estado fisiológico e a quantidade de basófilos foi maior em fêmeas não gestantes. Para monócitos os resultados foram em geral superiores nas cabras não gestantes e com 120 a 135 dias de gestação. Com relação a ordem de parição observou-se que fêmeas com mais de quatro partos apresentaram menores valores de VG, não havendo diferenças nos outros parâmetros do eritrograma. A LG foi maior na cabras com quatro partos, principalmente devido ao aumento de neutrófilos, enquanto que a quantidade de linfócitos foi menor nestas cabras. Os resultados encontrados evidenciaram a influência da gestação, do pós-parto e da ordem de parto das fêmeas da raça Saanen estudadas sobre os parâmetros hematológicos e também a necessidade da realização de estudos para se determinar os valores de referência do hemograma dos caprinos para cada tipo de criação, estado fisiológico e raça