RESUMO

Beef production systems primarily use natural service (NS) for breeding. However, a significant number of bulls used for NS are subfertile, limiting the profitability of the cow-calf operations. Therefore, producers should select bulls based on breeding soundness evolutions (BSE) to ensure higher pregnancy rates. Several factors can affect the bull ability to pass a BSE. We hypothesize that calving date would be a factor that affects the bull probability of approval at the first BSE. For this purpose, a multivariate logistic regression in a dataset of 14,737 BSEs from young Nellore bulls was used. Correlations between calving date, biometrics, and semen traits were evaluated using Pearson's correlation coefficient. Our results demonstrated that the calving date affected the probability of approval at the first BSE (p < .05). Indeed, the variable that added more information to our model was the calving date, far more than the age group of the bulls according to Akaike's information criterion. Hence, bulls born on day 0 of the calving season have 1.26 more chances to be approved at the first BSE than bulls born 21 days later. This result highlights the importance of getting the dams of future bulls pregnant as soon as possible in the breeding season. In addition, the calving season should be no longer than 47 days to achieve 80% BSE approval in 20-22 months old Nellore bulls. The strongest correlation was with SC, which decreased as the calving date increased. Therefore, the calving date may be used as a predictor of the outcome of the first BSE in young bulls. In that way, the calving date can help seedstock producers to maximize efficiency in making crucial management decisions during the breeding and calving season including nutrition, reproductive, and culling.

Assuntos

RESUMO

The objective of this study was to identify the prevalence of the main pathologies that affect the genital organs of young bulls. We used a database that contained data for 6,408 young Nelore bulls. The data were collected from June to August 2004 and 2005. The bulls were evaluated by andrological examination and semen samples were collected with the aid of an electroejaculation device. The animals were classified in terms of their sexual maturity as animals suitable for reproduction, animals suitable for reproduction in terms of natural service, animals temporarily unfit for reproduction, and animals excluded from reproduction. The reproductive disorders recorded in the excluded animals were classified as penile, testicular, anterior or posterior limb, epididymal, spermatic cord, spermatic, anal sphincter, foreskin, systemic, and seminal vesicle alterations. We used descriptive statistics and analysis of variance to analyze the data. Of the 6,408 bulls evaluated, 309 animals were excluded from reproduction (4.82%). The majority of the excluded bulls (31.7%) suffered from testicular-related pathologies (testicular asymmetry, small scrotal circumference for their age, orchitis, and hydrocele (64.28%, 32.65%, 2.04%, and 1.02%, respectively), seminal vesicle alterations (31.39%), sperm defects (17.15%), and penile alterations (6.79%). Of the 309 animals excluded from reproduction, 21 (6.79%of the excluded and 0.32% of the total animals) suffered from some type of penile alteration, such as persistence of the frenulum (16/21) and total or partial penile adhesion (5/21). Confining the herd for two months and subjecting the animals to their first andrological examination at a younger than usual age, with the objective of selling them, could be why there were high incidences of seminal vesicle pathologies (owing to the homosexual behavior of the males) and of penises with high [...].(AU)

Objetivou-se identificar a prevalência das principais patologias que acometem os órgãos genitais de tourinhos jovens. Foi utilizado um banco de dados de 6408 touros jovens da raça Nelore, nos meses de junho a agosto de 2004 e 2005. Os tourinhos foram avaliados por meio de exame andrológico e o sêmen coletado com auxílio do eletroejaculador. A maturidade sexual dos animais foi classificada em: animais aptos à reprodução, animais aptos à reprodução em regime de monta natural, animais temporariamente inaptos à reprodução e animais descartados. As afecções reprodutivas registradas nos animais descartados foram distribuídas em: alterações de pênis, testículos, membros anteriores ou posteriores, epidídimo, cordão espermático, alterações espermáticas, alterações do esfíncter anal, prepúcio, sistêmicas e de vesícula seminal. Análises descritiva e de Variância foram realizadas para análise dos dados. Dos 6408 touros avaliados, 309 animais foram descartados da reprodução (4,82%).A maioria dos touros descartados (31,7%) apresentou patologias relacionadas ao testículo (assimetria testicular, baixo perímetro escrotal para a idade, orquite e hidrocele, com valores de 64,28, 32,65, 2,04 e 1,02%, respectivamente), e vesículas seminais (31,39%), seguidas pelos defeitos espermáticos (17,15% dos descartados) e alterações de pênis (6,79%). Dos 309 animais descartados da reprodução, 21 (6,79% dos descartados e 0,32% do total de animais) apresentaram algum tipo de alteração peniana como persistência do frênulo (16/21) e aderências penianas, total ou parcial (5/21). O confinamento do rebanho por dois meses e a redução da idade dos animais para realização do primeiro exame andrológico, com objetivo de venda de animais precoces, podem ser os responsáveis pela maior incidência de patologias relacionadas às vesículas seminais [...].(AU)

Assuntos

RESUMO

The objective of this study was to identify the prevalence of the main pathologies that affect the genital organs of young bulls. We used a database that contained data for 6,408 young Nelore bulls. The data were collected from June to August 2004 and 2005. The bulls were evaluated by andrological examination and semen samples were collected with the aid of an electroejaculation device. The animals were classified in terms of their sexual maturity as animals suitable for reproduction, animals suitable for reproduction in terms of natural service, animals temporarily unfit for reproduction, and animals excluded from reproduction. The reproductive disorders recorded in the excluded animals were classified as penile, testicular, anterior or posterior limb, epididymal, spermatic cord, spermatic, anal sphincter, foreskin, systemic, and seminal vesicle alterations. We used descriptive statistics and analysis of variance to analyze the data. Of the 6,408 bulls evaluated, 309 animals were excluded from reproduction (4.82%). The majority of the excluded bulls (31.7%) suffered from testicular-related pathologies (testicular asymmetry, small scrotal circumference for their age, orchitis, and hydrocele (64.28%, 32.65%, 2.04%, and 1.02%, respectively), seminal vesicle alterations (31.39%), sperm defects (17.15%), and penile alterations (6.79%). Of the 309 animals excluded from reproduction, 21 (6.79%of the excluded and 0.32% of the total animals) suffered from some type of penile alteration, such as persistence of the frenulum (16/21) and total or partial penile adhesion (5/21). Confining the herd for two months and subjecting the animals to their first andrological examination at a younger than usual age, with the objective of selling them, could be why there were high incidences of seminal vesicle pathologies (owing to the homosexual behavior of the males) and of penises with high [...].

Objetivou-se identificar a prevalência das principais patologias que acometem os órgãos genitais de tourinhos jovens. Foi utilizado um banco de dados de 6408 touros jovens da raça Nelore, nos meses de junho a agosto de 2004 e 2005. Os tourinhos foram avaliados por meio de exame andrológico e o sêmen coletado com auxílio do eletroejaculador. A maturidade sexual dos animais foi classificada em: animais aptos à reprodução, animais aptos à reprodução em regime de monta natural, animais temporariamente inaptos à reprodução e animais descartados. As afecções reprodutivas registradas nos animais descartados foram distribuídas em: alterações de pênis, testículos, membros anteriores ou posteriores, epidídimo, cordão espermático, alterações espermáticas, alterações do esfíncter anal, prepúcio, sistêmicas e de vesícula seminal. Análises descritiva e de Variância foram realizadas para análise dos dados. Dos 6408 touros avaliados, 309 animais foram descartados da reprodução (4,82%).A maioria dos touros descartados (31,7%) apresentou patologias relacionadas ao testículo (assimetria testicular, baixo perímetro escrotal para a idade, orquite e hidrocele, com valores de 64,28, 32,65, 2,04 e 1,02%, respectivamente), e vesículas seminais (31,39%), seguidas pelos defeitos espermáticos (17,15% dos descartados) e alterações de pênis (6,79%). Dos 309 animais descartados da reprodução, 21 (6,79% dos descartados e 0,32% do total de animais) apresentaram algum tipo de alteração peniana como persistência do frênulo (16/21) e aderências penianas, total ou parcial (5/21). O confinamento do rebanho por dois meses e a redução da idade dos animais para realização do primeiro exame andrológico, com objetivo de venda de animais precoces, podem ser os responsáveis pela maior incidência de patologias relacionadas às vesículas seminais [...].

Assuntos

RESUMO

Nonlinear mixed models were used to describe longitudinal scrotal circumference (SC) measurements of Nellore bulls. Models comparisons were based on Akaike's information criterion, Bayesian information criterion, error sum of squares, adjusted R2 and percentage of convergence. Sequentially, the best model was used to compare the SC growth curve in bulls divergently classified according to SC at 18-21 months of age. For this, bulls were classified into five groups: SC < 28cm; 28cm ≤ SC < 30cm, 30cm ≤ SC < 32cm, 32cm ≤ SC < 34cm and SC ≥ 34cm. Michaelis-Menten model showed the best fit according to the mentioned criteria. In this model, ß1 is the asymptotic SC value and ß2 represents the time to half-final growth and may be related to sexual precocity. Parameters of the individual estimated growth curves were used to create a new dataset to evaluate the effect of the classification, farms, and year of birth on ß1 and ß2 parameters. Bulls of the largest SC group presented a larger predicted SC along all analyzed periods; nevertheless, smaller SC group showed predicted SC similar to intermediate SC groups (28cm ≤ SC < 32cm), around 1200 days of age. In this context, bulls classified as improper for reproduction at 18-21 months old can reach a similar condition to those considered as good condition. In terms of classification at 18-21 months, asymptotic SC was similar among groups, farms and years; however, ß2 differed among groups indicating that differences in growth curves are related to sexual precocity. In summary, it seems that selection based on SC at too early ages may lead to discard bulls with suitable reproductive potential.

Assuntos

RESUMO

Avaliou-se a eficiência de dois indutores da ovulação: cipionato de estradiol (CE) e benzoato de estradiol (BE), na inseminação artificial em tempo fixo (IATF). Foram utilizadas 128 novilhas. Todos os animais foram submetidos ao mesmo protocolo de sincronização, a partir do dia 8 os animais foram distribuídos em dois tratamentos: Tratamento com CE no dia 8 (64 novilhas) e tratamento com BE no dia 9 (64 novilhas). Quanto ao número de folículos, só observou-se diferença significativa entre os tratamentos no dia 8. Não houve diferença (p>0,05) para taxa de crescimento folicular, diâmetro do folículo dominante (10,97 ± 1,24 e 9,77 ± 1,36 mm), e intervalo da ovulação à inseminação artificial (13,20 ± 3,79 e 23,00 ± 14,28 horas) entre os tratamentos. A retirada do dispositivo de progesterona à ovulação, em horas, foi de 60,60±3,69 e 74,75±15,17 horas, respectivamente para CE e BE (p 0,05). Houve diferença (p 0,05) entre os tratamentos para a taxa de ovulação, que foi de 90,00% e 40,00% para CE e BE, respectivamente. A taxa de prenhez foi de 37,3% (p0,05) para ambos tratamentos. A administração de CE no dia 8 possibilitou a redução de um manejo na IATF em novilhas sem influenciar na taxa de prenhez.(AU)

We evaluated the efficiency of two ovulation induction: estradiol cypionate (EC) and estradiol benzoate (EB), at fixed time artificial insemination (TAI). 128 heifers were used. All animals were subjected to the same synchronization protocol, from the 8th day animals were divided into two treatments: Treatment with CE on the 8th (64 heifers) and treatment with EB on Day 9 (64 heifers). Regarding the number of follicles, only there was a significant difference between treatments at day 8. There was no difference (p> 0.05) for follicular growth rate, diameter of the dominant follicle (10.97 ± 1.24 and 9, 77 ± 1.36 mm) and range of ovulation in artificial insemination (13.20 ± 3.79 and 23.00 ± 14.28 hours) between treatments. The withdrawal of progesterone device ovulation in hours was 60.60 ± 3.69 and 74.75 ± 15,17 hours respectively for CE and BE (p <0.05). There were differences (p <0.05) between treatments for ovulation rate, which was 90.00% and 40.00% for CE and BE, respectively. The pregnancy rate was 37.3% (p 0.05) for both treatments. The EC administration on 81 Centro enabled the reduction of management in the TAI in heifers without influencing pregnancy rate.(AU)

Se evaluó la eficiencia de la inducción de la ovulación de dos: cipionato de estradiol (CE) y benzoato de estradiol (EB), en la inseminación artificial de tiempo fijo (TAI). Se utilizaron 128 novillas. Todos los animales fueron sometidos al mismo protocolo de sincronización, a partir de los animales se dividieron en dos tratamientos 8º: El tratamiento con CE en la octava (64 novillas) y el tratamiento con EB en el Día 9 (64 novillas). En cuanto al número de folículos, solamente había una diferencia significativa entre los tratamientos en el día 8. No hubo diferencia (p> 0,05) para la tasa de crecimiento folicular, el diámetro del folículo dominante (10,97 ± 1,24 y 9, 77 ± 1,36 mm) y el rango de la ovulación en la inseminación artificial (13,20 ± 3,79 y 23,00 ± 14,28 horas) entre tratamientos. La retirada del dispositivo de progesterona ovulación en horas fue 60,60 ± 3,69 y 74,75 ± 15,17 horas, respectivamente, para el CE y BE (p <0,05). Hubo diferencias (p <0,05) entre los tratamientos para la tasa de ovulación, que fue 90,00% y 40,00% para CE y ser, respectivamente. La tasa de embarazo fue de 37,3% (p 0,05) en ambos tratamientos. La administración CE el 8 de activar la reducción de la gestión en el TAI en novillas sin influir en la tasa de embarazo.(AU)

Assuntos

RESUMO

Avaliou-se a eficiência de dois indutores da ovulação: cipionato de estradiol (CE) e benzoato de estradiol (BE), na inseminação artificial em tempo fixo (IATF). Foram utilizadas 128 novilhas. Todos os animais foram submetidos ao mesmo protocolo de sincronização, a partir do dia 8 os animais foram distribuídos em dois tratamentos: Tratamento com CE no dia 8 (64 novilhas) e tratamento com BE no dia 9 (64 novilhas). Quanto ao número de folículos, só observou-se diferença significativa entre os tratamentos no dia 8. Não houve diferença (p>0,05) para taxa de crescimento folicular, diâmetro do folículo dominante (10,97 ± 1,24 e 9,77 ± 1,36 mm), e intervalo da ovulação à inseminação artificial (13,20 ± 3,79 e 23,00 ± 14,28 horas) entre os tratamentos. A retirada do dispositivo de progesterona à ovulação, em horas, foi de 60,60±3,69 e 74,75±15,17 horas, respectivamente para CE e BE (p 0,05). Houve diferença (p 0,05) entre os tratamentos para a taxa de ovulação, que foi de 90,00% e 40,00% para CE e BE, respectivamente. A taxa de prenhez foi de 37,3% (p0,05) para ambos tratamentos. A administração de CE no dia 8 possibilitou a redução de um manejo na IATF em novilhas sem influenciar na taxa de prenhez.

We evaluated the efficiency of two ovulation induction: estradiol cypionate (EC) and estradiol benzoate (EB), at fixed time artificial insemination (TAI). 128 heifers were used. All animals were subjected to the same synchronization protocol, from the 8th day animals were divided into two treatments: Treatment with CE on the 8th (64 heifers) and treatment with EB on Day 9 (64 heifers). Regarding the number of follicles, only there was a significant difference between treatments at day 8. There was no difference (p> 0.05) for follicular growth rate, diameter of the dominant follicle (10.97 ± 1.24 and 9, 77 ± 1.36 mm) and range of ovulation in artificial insemination (13.20 ± 3.79 and 23.00 ± 14.28 hours) between treatments. The withdrawal of progesterone device ovulation in hours was 60.60 ± 3.69 and 74.75 ± 15,17 hours respectively for CE and BE (p <0.05). There were differences (p <0.05) between treatments for ovulation rate, which was 90.00% and 40.00% for CE and BE, respectively. The pregnancy rate was 37.3% (p 0.05) for both treatments. The EC administration on 81 Centro enabled the reduction of management in the TAI in heifers without influencing pregnancy rate.

Se evaluó la eficiencia de la inducción de la ovulación de dos: cipionato de estradiol (CE) y benzoato de estradiol (EB), en la inseminación artificial de tiempo fijo (TAI). Se utilizaron 128 novillas. Todos los animales fueron sometidos al mismo protocolo de sincronización, a partir de los animales se dividieron en dos tratamientos 8º: El tratamiento con CE en la octava (64 novillas) y el tratamiento con EB en el Día 9 (64 novillas). En cuanto al número de folículos, solamente había una diferencia significativa entre los tratamientos en el día 8. No hubo diferencia (p> 0,05) para la tasa de crecimiento folicular, el diámetro del folículo dominante (10,97 ± 1,24 y 9, 77 ± 1,36 mm) y el rango de la ovulación en la inseminación artificial (13,20 ± 3,79 y 23,00 ± 14,28 horas) entre tratamientos. La retirada del dispositivo de progesterona ovulación en horas fue 60,60 ± 3,69 y 74,75 ± 15,17 horas, respectivamente, para el CE y BE (p <0,05). Hubo diferencias (p <0,05) entre los tratamientos para la tasa de ovulación, que fue 90,00% y 40,00% para CE y ser, respectivamente. La tasa de embarazo fue de 37,3% (p 0,05) en ambos tratamientos. La administración CE el 8 de activar la reducción de la gestión en el TAI en novillas sin influir en la tasa de embarazo.

Assuntos

RESUMO

Background: One of the most important parameters to be considered in the assessment of male fertility or in the evaluation of methods to preserve sperm cells is the study of sperm viability. Considering that semen quality is of great importance for artificial insemination AI) in sows and for the production of an optimal number of piglets, complementary test results can be correlated with the number of piglets born after AI. The present study aimed to characterise the seminal pattern of breeding boars from two commercial lines and to correlate this pattern with the prolificacy of sows.Materials, Methods & Results: The reproductive performance of four boars from two commercial lines (A and B) was determined by evaluating physical and morphological semen parameters and by conducting a complementary analysis of semen. Semen was subjected to the following parameters: total sperm motility, sperm vigor, major sperm defects, minor sperm defects, and total sperm defects, in addition to complementary tests (supravital staining and hypoosmotic swelling tests). The semen was evaluated immediately after collection and every 12 h for up to 72 h of cold storage. A total of 163 breeding sows were inseminated. To evaluate sow prolificacy, the total number of piglets born was recorded. In general, the values obtained for the tests assessing sperm viability (particularly sperm motility and...(AU)

Assuntos

RESUMO

O estudo teve como objetivo avaliar o efeito da inclusão de monensina sódica no concentrado inicial de bezerras lactantes, sobre o ganho de peso, perímetro torácico, altura de cernelha, altura de garupa e comprimento corporal. Foram utilizadas 12 bezerras divididas em dois grupos experimentais de acordo com a data de nascimento. Foram avaliados os tratamentos controle (sem suplementação com monensina) e suplementação diária com 0,4 mg de monensina/kg de peso corporal, a dosagem de monensina iniciou em 0,2 mg/kg peso vivo, para adaptação dos animais, sendo os animais acompanhados a partir dos 30 dias até os 86 dias de idade. Os parâmetros avaliados semanalmente foram peso corporal, perímetro torácico, altura de cernelha, altura da garupa e comprimento corporal. Tais parâmetros não apresentaram variação em função da suplementação com monensina, o menor rendimento observado para o grupo suplementado pode ter sido decorrente da diminuição do consumo. A suplementação de monensina não apresentou efeito sobre desempenho ponderal de bezerras leiteiras em sistema de desaleitamento precoce.

The objective of the present study was to evaluate the effects of the inclusion of sodium monensin on the starter concentrate of lactating heifers on weight gain, chest girth, withers height, hip height and body length. Twelve heifers were divided into two experimental groups according to date of birth: a control group without supplementation and a daily supplemented group with 0.4 mg of sodium monensin per kg of body weight. The animals were observed from thirty days of age until 86 days of age. Production parameters as body weight, chest girth, withers height, hip height and body length were weekly evaluated. These parameters did not show variation depending on supplementation with monensin, the lowest yield observed in the supplemented group may have been due to lower consumption. The supplementation of monensin had no effect on weight gain of dairy calves in early weaning system.

Assuntos

RESUMO

Background: One of the most important parameters to be considered in the assessment of male fertility or in the evaluation of methods to preserve sperm cells is the study of sperm viability. Considering that semen quality is of great importance for artificial insemination AI) in sows and for the production of an optimal number of piglets, complementary test results can be correlated with the number of piglets born after AI. The present study aimed to characterise the seminal pattern of breeding boars from two commercial lines and to correlate this pattern with the prolificacy of sows.Materials, Methods & Results: The reproductive performance of four boars from two commercial lines (A and B) was determined by evaluating physical and morphological semen parameters and by conducting a complementary analysis of semen. Semen was subjected to the following parameters: total sperm motility, sperm vigor, major sperm defects, minor sperm defects, and total sperm defects, in addition to complementary tests (supravital staining and hypoosmotic swelling tests). The semen was evaluated immediately after collection and every 12 h for up to 72 h of cold storage. A total of 163 breeding sows were inseminated. To evaluate sow prolificacy, the total number of piglets born was recorded. In general, the values obtained for the tests assessing sperm viability (particularly sperm motility and...

Assuntos