Relationship between body weight and scrotal circumference in growing Pelibuey sheep raised under tropical conditions / Relação entre o peso corporal e a circunferência escrotal em ovinos Pelibuey em crescimento criados em condições tropicais

The body weight (BW) of an animal is a vital economic trait that might help in decision-making in the handling of animals. The objective of the present study was to develop equations for the prediction of BW in Pelibuey sheep using scrotal circumference (SC). The BW (23.40 ± 6.96 kg) and SC (20.25 ± 6.19 cm) have been recorded in 405 male Pelibuey at the Southeastern Center for Ovine Integration, Mexico. Linear, logarithmic, quadratic, exponential, cubic, and power regression models were used for data analysis. Pearson correlation (R), Coefficient of determination (R2), Adjusted coefficient of determination (Adj.R2) Root mean square error (RMSE), Akaike information criterion (AIC), and Bayesian information criterion (BIC) were used to select the best model. Power regression model showed the highest R (0.93), R2 (0.86), Adj.R2 (0.86) and lowest RMSE (0.02), AIC (-989.44) and BIC (-981.44). The current study suggests that SC might be used as the only predictor for BW of growing Pelibuey sheep raised under tropical conditions.

O peso corporal (PC) do animal é uma característica econômica importante, que pode auxiliar na tomada de decisões no manejo dos animais. O objetivo do presente estudo foi desenvolver equações para a predição do PC em ovinos Pelibuey por meio da circunferência escrotal (CE). O PC (23,40±6,96kg) e a CE (20,25±6,19cm) foram registrados em 405 ovinos machos da raça Pelibuey no Centro de Integração Ovina da Região Sudeste do México. Os modelos lineares, logarítmicos, quadráticos, exponenciais, cúbicos e de regressão de potência foram utilizados para a análise dos dados. A correlação de Pearson (R), o coeficiente de determinação (R2), o coeficiente de determinação ajustado (Adj.R2), o erro do quadrado médio (EQM), o critério de informação de Akaike (AIC) e o critério de informação bayesiano (BIC) foram usados para selecionar o melhor modelo. O modelo de regressão de potência apresentou maiores R (0,93), R2 (0,86), Adj.R2 (0,86) e menores EQM (0,02), AIC (-989,44) e BIC (-981,44). O estudo atual sugere que a CE pode ser usada como um único preditor para o PC de ovinos Pelibuey em crescimento criadas em condições tropicais.

Association of visual scores with reproductive traits in Nelore cattle using Bayesian Inference / Associação de escores visuais com características reprodutivas em bovinos Nelore utilizando Inferência Bayesiana

The use of morphological traits assessed using visual scores as indirect selection criteria in cattle has the advantage of evaluating young animals regarding potential productive and reproductive performance. This enables breeders to make earlier decisions compared to later measurements, such as scrotal circumference at 450 days (SC450) and stayability (STAY). The aim of this study was to estimate the genetic parameters for visual score traits and their associations with reproductive traits: scrotal circumference at 365 days of age (SC365), SC450, STAY, probability of precocious calving (PPC30) and age at first calving (AFC) in Nellore cattle. Visual score data from 4,175 Nellore cattle, with an average age of 22 months, and reproductive data from 3,075 cattle belonging to the HoRa Genetics Provada herd were used. The morphological traits were evaluated by the MERCOS methodology. The heritability estimates obtained ranged from 0.15 to 0.28 for visual scores and 0.10 to 0.54 for reproductive traits. Genetic correlations between visual scores and reproductive traits were generally low, except between: muscularity and PPC30; structure and STAY; racial and SC450; conformation and SC365, SC450, STAY, and AFC; navel and STAY and AFC; and sacrum and SC365, STAY, and AFC, which were moderate to high. The identification of animals with flat sacral bone (not protruding or sloping) can also be an efficient characteristic in the identification for early pregnancy, and together with the musculature score, they can be related to animals with lower age at the first calving.(AU)

A utilização de características morfológicas de bovinos, pelo uso de escores visuais como critério de seleção indireta tem como vantagem a avaliação em animais jovens quanto ao potencial desempenho produtivo e reprodutivo, antecipando a tomada de decisão em comparação a medidas tomadas de forma tardia, como perímetro escrotal aos 450 dias (PE450) e stayability (STAY). Objetivou-se estimar os parâmetros genéticos para características de escores visuais e a associação dessas com características reprodutivas, perímetro escrotal aos 365 (PE365) dias de idade, PE450, STAY, probabilidade de parto precoce (3P) e idade ao primeiro parto (IPP) em bovinos Nelore. Foram utilizadas informações de escores visuais e de reprodução de 4.175 e 3.075 bovinos, respectivamente, com idade média de 22 meses, pertencentes a fazenda HoRa Genética Provada. As características morfológicas foram avaliadas pela metodologia MERCOS. As estimativas de herdabilidade obtidas apresentam grande amplitude, variando de 0,15 a 0,28 para escores visuais e 0,10 a 0,54 para características reprodutivas. As correlações genéticas entre característica de escores visuais e reprodução foram, de maneira geral baixas (0.03-0.66), com exceção entre a musculosidade e 3P, estrutura e STAY, racial e PE450, conformação com PE365, PE450, STAY e IPP, ônfalo com STAY e IPP, e sacro com PE365, STAY e IPP, que foram moderadas a altas. A identificação de animais com melhor osso sacro (mesmo nível das ancas), ou seja, não saliente ou inclinado pode ser uma característica eficiente na identificação para prenhez precoce, e juntamente ao escore de musculatura poderão ser relacionados a animais com menor idade ao primeiro parto.(AU)

Genetic parameters for growth, reproductive, and carcass traits in Tabapuã cattle

We aimed to estimate genetic parameters for growth, reproductive, and carcass traits in Tabapuã cattle. Phenotypic data were collected between 1990 and 2019 in 1,218 farms, and the pedigree file had 340,868 animals. The traits evaluated were body weight at 120 (W120), 210 (W210), 365 (W365), and 550 (W550) days of age; age at first calving (AFC), scrotal circumference at 365 days of age (SC365), ribeye area (REA), backfat thickness (BF), and rump fat thickness (RF). The (co)variance components were estimated using the restricted maximum likelihood method, considering single and two-traits animal models. For all traits, the models considered fixed, direct additive genetic, and residual random effects. In addition, for W120 and W210, the maternal additive genetic and maternal permanent environmental effects were also included. Heritabilities for W120, W210, W365, W550, SC365, REA, BF, and RF were of moderate magnitude (0.15, 0.16, 0.23, 0.19, 0.22, 0.36, 0.31, and 0.27, respectively). Low heritability was observed for AFC (0.07). The genetic correlations between growth traits were higher than 0.90, while AFC and SC365 presented negative moderate correlation (−0.66). The REA showed low genetic correlations with BF (0.07) and RF (0.07), whereas BF and RF were highly correlated (0.77). Considering the heritability estimates, selection for AFC would result in limited genetic gain, while for the other traits, it would be satisfactory. Based on the high genetic correlations between growth traits, selection of Tabapuã animals can be performed at younger ages. Additionally, animals can be indirectly selected for AFC through SC365, and only one fat thickness trait may be used in the selection process considering the high genetic correlation and similar heritability values for BF and RF.(AU)

Scrotal circumference in Karagouniko and Chios sheep in relation to the aerial environment

Local breeds are a valuable asset in sheep farming systems in Greece and other Mediterranean countries. Among these, Karagouniko and Chios sheep hold a special position, participating in numerous genetic improvement programs, but a research gap exists on their scrotal circumference (SC) in relation to the environmental parameters photoperiod (PHOTO), air temperature, sunshine and rainfall. Therefore, four seasons were examined: April-June and July-September (Long days, increasing and decreasing photoperiod length, respectively), and October-December and January-March (Short days, decreasing and increasing photoperiod length, respectively). Repeated measures analysis of variance and linear correlation analysis were used to investigate the effect of the period on SC and the relationships of SC and each of the environmental parameters above, respectively, in both breeds. Also, independent t-tests were used to investigate SC differences between Karagouniko and Chios. A progressive increase of SC in both breeds coincided with the lowering of PHOTO from April-June to October-December. A significant correlation was confirmed between the SC of each breed and PHOTO, shedding light on the importance of this parameter on SC. Chios sheep had significantly larger (P < 0.05) SC (35.23 cm) than the Karagouniko one (34.59 cm). Better exploitation of these sheep breeds could be derived from the current study's findings.

Growth performance, reproductive parameters and fertility measures in young Nellore bulls with divergent feed efficiency

The growth, sexual maturity and fertility-related parameters related of young Nellore bulls with divergent residual feed intake (RFI) raised on pasture were evaluated. After classification of 48 young males as low and high RFI (more and less efficient, respectively), the animals were evaluated for growth and reproductive parameters at 28-day intervals from 14.3 to 24.6 months of age. The semen was cryopreserved in the last sampling and fresh and post-thaw semen samples were evaluated. Low RFI bulls exhibited higher initial and final body weight (P < 0.05), but feed intake, body condition score and growth measures evaluated by carcass ultrasound were unaffected by RFI (P > 0.05). The scrotal circumference, sperm concentration, defects, and quality of fresh semen, and ultrasonographic testicular characteristics were unaffected by RFI (P > 0.05). However, velocity parameters such as average path and curvilinear velocities determined by computer-assisted sperm analysis of thawed semen submitted to the rapid thermoresistance test were improved (P < 0.05) in low RFI bulls, but this improvement in quality did not enhance in vitro sperm fertilizing ability. Our results demonstrated significant differences in metabolism and growth performance between bulls of divergent RFI. In addition, there was slight improvement in the semen quality of bulls with low RFI bulls, but this did not enhance in vitro fertilizing ability. Selection of beef bulls for RFI can be performed, which will result in economic benefits by improving the growth performance of the animals without affecting reproductive parameters.(AU)

Reproductive parameters of lambs immunocastrated with anti-GnRH vaccine

Abstract The objective of this study was to evaluate the testicular biometric, seminal, and plasma testosterone levels in lambs subjected to an anti-GnRH vaccine as a method of castration. Thirty entire, crossbred Santa Inês male lambs were randomly distributed into three treatment (T): T1 was the control group, with the administration of 1 mL of saline solution subcutaneously (SC); 1.0 and 0.5 mL of an anti-GnRH vaccine were administered SC in T2 and T3, respectively. Testicular biometric variables, physical and morphological variables of semen, and plasma testosterone concentrations were evaluated. At D60, there was a reduction in testicular length, width, thickness, and scrotal circumference of the immunocastrated animals regardless of the vaccine dose used (P < 0.05). A reduction in semen physical variables at both dosages (P < 0.05) was observed, with azoospermia, in 80% and 70% of animals in the T2 and T3 groups, respectively. At D60, the immunocastrated animals also showed an increase in spermatozoa defects (P < 0.05), whereas plasma testosterone concentration decreased (P < 0.05). Immunocastration of lambs using the Bopriva vaccine at doses of 1.0 and 0.5 mL is efficient in inducing azoospermia in up to 80% of animals, although two doses in a 30-day interval are necessary for it to be an effective and safe method. Efficacy was demonstrated through a reduction in serum testosterone levels, testicular biometry, and seminal fluid analysis. Considering the efficacy of both doses in this study, we recommend using the lower dose (0.5 mL), which will allow for a 50% reduction in vaccine costs.

Correlations between body measures with live weight in young male goats

Data analysis in goat production, such as those related to body and scrotal measurements, indicate the productive and reproductive animal development. The current study aimed to evaluate the correlations between thoracic perimeter (TP), body length (BL), body compacity (BC), body volume (BV), and scrotal circumference (SC) with body weight (BW) in young male goats of Saanen and Boer breeds. It was used 38 Saanen and 24 Boer male goats, with age average of 7.2 ± 2.0 months. Thoracic perimeter and body length measurements were obtained using a tape measure (cm) and the live weight (kg) a mechanic scale. The variables body compacity (BC) and body volume (BV) were calculated using the equations: and . Boer breed showed live weight and body compacity higher than Saanen breed (p < 0.05). Regarding correlations between biometric measurements and body weight, we did not find any statistical differences between the breeds (p > 0.05). The scrotal circumference presented the lowest association with body weight (p < 0.05). However, all biometric measurements showed highly significant correlations with live body (p < 0.01). In conclusion, thoracic perimeter was the main measure of body weight predictor, considering efficiency and practical aspects.(AU)

Correlations between body measures with live weight in young male goats

Data analysis in goat production, such as those related to body and scrotal measurements, indicate the productive and reproductive animal development. The current study aimed to evaluate the correlations between thoracic perimeter (TP), body length (BL), body compacity (BC), body volume (BV), and scrotal circumference (SC) with body weight (BW) in young male goats of Saanen and Boer breeds. It was used 38 Saanen and 24 Boer male goats, with age average of 7.2 ± 2.0 months. Thoracic perimeter and body length measurements were obtained using a tape measure (cm) and the live weight (kg) a mechanic scale. The variables body compacity (BC) and body volume (BV) were calculated using the equations: and . Boer breed showed live weight and body compacity higher than Saanen breed (p 0.05). The scrotal circumference presented the lowest association with body weight (p < 0.05). However, all biometric measurements showed highly significant correlations with live body (p < 0.01). In conclusion, thoracic perimeter was the main measure of body weight predictor, considering efficiency and practical aspects.

Hipoplasia testicular em bovinos: causas e consequências / Testicular hypoplasia in cattle: causes and consequences

A hipoplasia testicular ocorre na maioria dos animais domésticos, sendo caracterizada pela ausência ou diminuição do desenvolvimento do epitélio germinativo dos túbulos seminíferos. Apesar de nem todas as causas da hipoplasia testicular estarem completamente elucidadas, pode-se destacar as gênicas, as cromossômicas e as ambientais. A manifestação mais comum da hipoplasia gonadal clássica é de origem congênita e de caráter hereditário, determinada por um gene autossômico recessivo de penetrância incompleta. Apesar dos relatos de frequência serem escassos, essa patologia é descrita em quase todas as raças bovinas. Em rebanhos com alto grau de consanguinidade ou com uso intensivo de reprodutores homozigotos recessivos para a patologia, podem ocorrer manifestações em 5 a 15% dos animais. Nos casos de hipoplasia testicular, causada por genes recessivos de penetrância incompleta, tais genes podem passar para as gerações seguintes, causando subfertilidade tanto em machos como em fêmeas, sendo recomendada a eliminação de animais clinicamente suspeitos por assimetria testicular ou por baixo padrão de circunferência escrotal para a idade e peso. Touros com hipoplasia unilateral ou parcial são animais azoospérmicos ou oligospérmicos, porém quadros moderados a leves podem não estar associados a problemas de qualidade seminal, possibilitando que touros assintomáticos transmitam genes indesejáveis às próximas gerações. O estabelecimento de critérios rígidos de verificação de aspectos clínico-andrológicos é imprescindível para um diagnóstico precoce e para a seleção preliminar de reprodutores bovinos. As avaliações genômicas são caminhos promissores para mapear e identificar os principais marcadores associados à expressão gênica da hipoplasia testicular, com sua possível aplicação para seleção de touros de elite.

Testicular hypoplasia occurs in most domestic animals and is characterized by the absence or decreased development of the germinative epithelium of the seminiferous tubules. Although not all causes of testicular hypoplasia are elucidated, we can highlight the genetic, chromosomal and environmental causes. The manifestation of the most common classic gonadal hypoplasia is from congenital causes, determined by an autosomal recessive gene of incomplete penetrance. Although reports of frequency are scarce, this pathology is described in almost all bovine breeds. In herds with a high degree of inbreeding or intensive use of subfertile bulls, manifestations may occur in 5% to 15% of the animals. In cases of testicular hypoplasia, caused by recessive genes of incomplete penetrance, such genes can pass on to the following generations, causing subfertility in both males and females, being recommended the elimination of animals clinically suspected by testicular asymmetry or by low standard of scrotal circumference for age and weight. Bulls with unilateral or partial hypoplasia are azoospermic or oligospermic, however moderate conditions may not be associated with seminal quality problems, allowing asymptomatic bulls to spread undesirable genes to the next generations. The establishment of strict criteria for checking clinical and andrological aspects is essential for an early diagnosis and preliminary Bull's selection. Genomic evaluation is a promising way to map and identify the main genetic markers associated with testicular hypoplasia expression genes and its use for bull's selection.

Hipoplasia testicular em bovinos: causas e consequências / Testicular hypoplasia in cattle: causes and consequences

A hipoplasia testicular ocorre na maioria dos animais domésticos, sendo caracterizada pela ausência ou diminuição do desenvolvimento do epitélio germinativo dos túbulos seminíferos. Apesar de nem todas as causas da hipoplasia testicular estarem completamente elucidadas, pode-se destacar as gênicas, as cromossômicas e as ambientais. A manifestação mais comum da hipoplasia gonadal clássica é de origem congênita e de caráter hereditário, determinada por um gene autossômico recessivo de penetrância incompleta. Apesar dos relatos de frequência serem escassos, essa patologia é descrita em quase todas as raças bovinas. Em rebanhos com alto grau de consanguinidade ou com uso intensivo de reprodutores homozigotos recessivos para a patologia, podem ocorrer manifestações em 5 a 15% dos animais. Nos casos de hipoplasia testicular, causada por genes recessivos de penetrância incompleta, tais genes podem passar para as gerações seguintes, causando subfertilidade tanto em machos como em fêmeas, sendo recomendada a eliminação de animais clinicamente suspeitos por assimetria testicular ou por baixo padrão de circunferência escrotal para a idade e peso. Touros com hipoplasia unilateral ou parcial são animais azoospérmicos ou oligospérmicos, porém quadros moderados a leves podem não estar associados a problemas de qualidade seminal, possibilitando que touros assintomáticos transmitam genes indesejáveis às próximas gerações. O estabelecimento de critérios rígidos de verificação de aspectos clínico-andrológicos é imprescindível para um diagnóstico precoce e para a seleção preliminar de reprodutores bovinos. As avaliações genômicas são caminhos promissores para mapear e identificar os principais marcadores associados à expressão gênica da hipoplasia testicular, com sua possível aplicação para seleção de touros de elite.(AU)

Testicular hypoplasia occurs in most domestic animals and is characterized by the absence or decreased development of the germinative epithelium of the seminiferous tubules. Although not all causes of testicular hypoplasia are elucidated, we can highlight the genetic, chromosomal and environmental causes. The manifestation of the most common classic gonadal hypoplasia is from congenital causes, determined by an autosomal recessive gene of incomplete penetrance. Although reports of frequency are scarce, this pathology is described in almost all bovine breeds. In herds with a high degree of inbreeding or intensive use of subfertile bulls, manifestations may occur in 5% to 15% of the animals. In cases of testicular hypoplasia, caused by recessive genes of incomplete penetrance, such genes can pass on to the following generations, causing subfertility in both males and females, being recommended the elimination of animals clinically suspected by testicular asymmetry or by low standard of scrotal circumference for age and weight. Bulls with unilateral or partial hypoplasia are azoospermic or oligospermic, however moderate conditions may not be associated with seminal quality problems, allowing asymptomatic bulls to spread undesirable genes to the next generations. The establishment of strict criteria for checking clinical and andrological aspects is essential for an early diagnosis and preliminary Bull's selection. Genomic evaluation is a promising way to map and identify the main genetic markers associated with testicular hypoplasia expression genes and its use for bull's selection.(AU)

Reproductive parameters of lambs immunocastrated with anti-GnRH vaccine

The objective of this study was to evaluate the testicular biometric, seminal, and plasma testosterone levels in lambs subjected to an anti-GnRH vaccine as a method of castration. Thirty entire, crossbred Santa Inês male lambs were randomly distributed into three treatment (T): T1 was the control group, with the administration of 1 mL of saline solution subcutaneously (SC); 1.0 and 0.5 mL of an anti-GnRH vaccine were administered SC in T2 and T3, respectively. Testicular biometric variables, physical and morphological variables of semen, and plasma testosterone concentrations were evaluated. At D60, there was a reduction in testicular length, width, thickness, and scrotal circumference of the immunocastrated animals regardless of the vaccine dose used (P < 0.05). A reduction in semen physical variables at both dosages (P < 0.05) was observed, with azoospermia, in 80% and 70% of animals in the T2 and T3 groups, respectively. At D60, the immunocastrated animals also showed an increase in spermatozoa defects (P < 0.05), whereas plasma testosterone concentration decreased (P < 0.05). Immunocastration of lambs using the Bopriva vaccine at doses of 1.0 and 0.5 mL is efficient in inducing azoospermia in up to 80% of animals, although two doses in a 30-day interval are necessary for it to be an effective and safe method. Efficacy was demonstrated through a reduction in serum testosterone levels, testicular biometry, and seminal fluid analysis. Considering the efficacy of both doses in this study, we recommend using the lower dose (0.5 mL), which will allow for a 50% reduction in vaccine costs.(AU)

Alternative adjustment of scrotal circumference for growth traits in Nellore cattle

The objective of this study was to estimate adjustment factors of scrotal circumference for growth traits in Nellore cattle. Measurement at post-yearling of scrotal circumference from 100,107 Nellore was adjusted for six traits: age (A), body weight (BW), hip height (HH), conformation (C), precocity (P), musculature (M), and simultaneously for age and the other five traits (A-BW, A-HH, A-C, A-P, A-M), body weight and the other four traits (BW-HH, BW-C, BW-P, BW-M), and hip height and the other three traits (HH-C, HH-P, HH-M). Standard values were 500 days, 300 kg, 135 cm, and 3, for age, body weight, hip height, and visual scores, respectively. Amplitudes of adjustment factor of scrotal circumference for age, body weight, and hip height were 0.6028, 0.4869, and 0.1572, respectively. Scrotal circumference is expected to grow, on average, 8.71 cm per 100 days of age, 6.51 cm per 100 kg of body weight, and 4.81 cm per 10 cm of hip height. The results showed higher amplitude in the adjustment factor of scrotal circumference for age and body weight (0.3429) compared with age and hip height and body weight and hip height (0.1271 and 0.0443, respectively). The amplitude observed in adjustment factor of scrotal circumference for conformation, precocity, and musculature were 0.1328, 0.1175, and 0.1160, respectively. Considering different adjustment factors of scrotal circumference can be useful for identifying better selection criteria for growth and/or sexual precocity in Nellore.(AU)

Adult and yearling pampas deer stags (Ozotoceros bezoarticus) display mild reproductive seasonal patterns with maximum values in autumn

The pampas deer is an endangered species, from which reproductive biology little is known. We aimed to describe and compare the reproductive seasonal patterns of adult and yearling pampas deer stags throughout the year, including morphological traits, testosterone concentration, sperm morphology and cryoresistance pattern changes. Six adult (AS) and five yearling (YS) stags were captured with anesthetic darts once in winter, spring, summer and autumn to study morphological variables, serum testosterone and semen. Adult males were heavier, their neck girth tended to be greater and their testosterone concentration was higher than in YS. Animals were heavier in summer and autumn. Neck girth and testosterone concentration were greater in autumn. Scrotal circumference, testicular volume and gonado-somatic index varied with seasons, decreasing from winter to spring, increasing in summer and remaining in greater values in autumn. Sperm quality had maximum values from summer to winter. However, the cryoresistance ratio of motility score was greater in spring. In conclusion, in the captivity conditions, pampas deer stags seems to present a light seasonal reproductive pattern, with maximum testis size, testosterone secretion and fresh semen quality in autumn. Nevertheless, sperm cryoresistance ratio seemed to remain stable along the year. Although YS were still growing, they achieved similar semen quality than AS.

Adult and yearling pampas deer stags (Ozotoceros bezoarticus) display mild reproductive seasonal patterns with maximum values in autumn

The pampas deer is an endangered species, from which reproductive biology little is known. We aimed to describe and compare the reproductive seasonal patterns of adult and yearling pampas deer stags throughout the year, including morphological traits, testosterone concentration, sperm morphology and cryoresistance pattern changes. Six adult (AS) and five yearling (YS) stags were captured with anesthetic darts once in winter, spring, summer and autumn to study morphological variables, serum testosterone and semen. Adult males were heavier, their neck girth tended to be greater and their testosterone concentration was higher than in YS. Animals were heavier in summer and autumn. Neck girth and testosterone concentration were greater in autumn. Scrotal circumference, testicular volume and gonado-somatic index varied with seasons, decreasing from winter to spring, increasing in summer and remaining in greater values in autumn. Sperm quality had maximum values from summer to winter. However, the cryoresistance ratio of motility score was greater in spring. In conclusion, in the captivity conditions, pampas deer stags seems to present a light seasonal reproductive pattern, with maximum testis size, testosterone secretion and fresh semen quality in autumn. Nevertheless, sperm cryoresistance ratio seemed to remain stable along the year. Although YS were still growing, they achieved similar semen quality than AS.(AU)

Testicular features of semi-confined Nellore bullssubjected to immunocastration / Características testiculares de touros Nelore semiconfinadossubmetidos a imunocastração

This study aimed to evaluate the effect of immunocastration on the scrotal circumference, as well as in the macroscopic and microscopic testicular features in Nellore bulls bred under a semi-confining system for 91 days. Sixty animals were divided into two groups: 30 intact animals (non-vaccinated) and 30 immunocastrated animals. The immunocastrated animals were treated with two anti-GnRH vaccine doses (BoprivaTM - Zoetis Australia Pty Ltd). The scrotal circumference (SC) was measured on days 0 and 56. Testicular parameters: biometry traits (length, width, and height ­ cm; volume ­ cm3) and weight (g) was measured on day 91. Three testicles from each group were histologically processed to find the seminiferous tubule diameter and epithelium thickness (µm). Data were analyzed in the Minitab® 19 statistical software. The macroscopic features (SC, and testes weight, volume, length, width, and height) and the microscopic features (seminiferous tubule diameter and epithelium thickness) were compared between the two groups through Student's t-test and Mann-Whitney test. All the values were lower (p<0.05) in animals immunized against GnRH, except for the right testis width and seminiferous tubule diameter. Results indicate that immunization against GnRH affected testicular development.(AU)

O objetivo do presente estudo foi avaliar o efeito da imunocastração no perímetro escrotal, assim como nas características testiculares macroscópicas e microscópicas de touros Nelore criados em um sistema de semiconfinamento por 91 dias. Sessenta animais foram divididos em dois grupos: 30 animais inteiros (não vacinados) e 30 imunocastrados. Os animais imunocastrados receberam duas doses de uma vacina anti-GnRH (Bopriva® - Zoetis Ltda). O perímetro escrotal (PE) foi mensurado nos dias 0 e 56. Parâmetros testiculares: atributos biométricos (comprimento, largura e altura ­ cm; volume cm3) e peso (g) foram medidos no dia 91. Três testículos de cada grupo foram processados para histologia clássica a fim de avaliar o diâmetro e a espessura do epitélio dos túbulos seminíferos (µm). Os dados foram analisados pelo software estatístico Minitab® 19. As médias das características macroscópicas (PE, peso, volume, comprimento, largura e altura dos testículos) e das microscópicas (diâmetro e espessura do epitélio dos túbulos seminíferos) foram comparadas entre os dois grupos pelos testes t de Student e Mann-Whitney. Todos os valores foram menores (p<0,05) em animais imunizados contra o GnRH, exceto a altura média do testículo direito e o diâmetro do túbulo seminífero. Os resultados indicam que a imunização contra o GnRH afeta o desenvolvimento testicular.(AU)

Testicular features of semi-confined Nellore bullssubjected to immunocastration / Características testiculares de touros Nelore semiconfinadossubmetidos a imunocastração

This study aimed to evaluate the effect of immunocastration on the scrotal circumference, as well as in the macroscopic and microscopic testicular features in Nellore bulls bred under a semi-confining system for 91 days. Sixty animals were divided into two groups: 30 intact animals (non-vaccinated) and 30 immunocastrated animals. The immunocastrated animals were treated with two anti-GnRH vaccine doses (BoprivaTM - Zoetis Australia Pty Ltd). The scrotal circumference (SC) was measured on days 0 and 56. Testicular parameters: biometry traits (length, width, and height ­ cm; volume ­ cm3) and weight (g) was measured on day 91. Three testicles from each group were histologically processed to find the seminiferous tubule diameter and epithelium thickness (µm). Data were analyzed in the Minitab® 19 statistical software. The macroscopic features (SC, and testes weight, volume, length, width, and height) and the microscopic features (seminiferous tubule diameter and epithelium thickness) were compared between the two groups through Student's t-test and Mann-Whitney test. All the values were lower (p<0.05) in animals immunized against GnRH, except for the right testis width and seminiferous tubule diameter. Results indicate that immunization against GnRH affected testicular development.(AU)

O objetivo do presente estudo foi avaliar o efeito da imunocastração no perímetro escrotal, assim como nas características testiculares macroscópicas e microscópicas de touros Nelore criados em um sistema de semiconfinamento por 91 dias. Sessenta animais foram divididos em dois grupos: 30 animais inteiros (não vacinados) e 30 imunocastrados. Os animais imunocastrados receberam duas doses de uma vacina anti-GnRH (Bopriva® - Zoetis Ltda). O perímetro escrotal (PE) foi mensurado nos dias 0 e 56. Parâmetros testiculares: atributos biométricos (comprimento, largura e altura ­ cm; volume cm3) e peso (g) foram medidos no dia 91. Três testículos de cada grupo foram processados para histologia clássica a fim de avaliar o diâmetro e a espessura do epitélio dos túbulos seminíferos (µm). Os dados foram analisados pelo software estatístico Minitab® 19. As médias das características macroscópicas (PE, peso, volume, comprimento, largura e altura dos testículos) e das microscópicas (diâmetro e espessura do epitélio dos túbulos seminíferos) foram comparadas entre os dois grupos pelos testes t de Student e Mann-Whitney. Todos os valores foram menores (p<0,05) em animais imunizados contra o GnRH, exceto a altura média do testículo direito e o diâmetro do túbulo seminífero. Os resultados indicam que a imunização contra o GnRH afeta o desenvolvimento testicular.(AU)

Reproductive disorders affecting 21-month-old bulls assessed by andrological examination / Afecções reprodutivas que acometem tourinhos (21 meses) avaliados por meio de exame andrológico

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 [...].

Reproductive disorders affecting 21-month-old bulls assessed by andrological examination / Afecções reprodutivas que acometem tourinhos (21 meses) avaliados por meio de exame andrológico

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)

Environmental effects on performance of progeny from different Nellore sires in Brazilian semiarid region / Fatores ambientais sobre o desempenho de progênies de diferentes touros da raça Nelore no semiárido brasileiro

The aim of this study was to evaluate the influence of environmental factors on the performance of progeny from different Nellore sires in Brazilian semiarid region. Data on live weight, average daily gain and scrotal circumference of 741 animals categorized as OR (open registry) or PB (purebred) and born from 27 sires were collected from a commercial farm located in Varzelândia-MG. Evaluations were taken at 12 (yearling) and 18months of age. Data were analyzed using the least-squares method, considering the effect of pedigree (OR or PB), sire, year of birth, month of birth and calf sex in the model. There was a significant influence of the pedigree, sex, month of birth and sire on animal's performance until yearling age, whereas the performance traits at 18months were influenced only by the month of birth and sire (P<0.05). Therefore, environmental factors such as year, month of birth and calf sex are important sources of variation on calf performance from birth to18 months and it should be considered when comparing and selecting animals based on these traits.(AU)

O objetivo deste trabalho foi avaliar a influência dos fatores ambientais sobre o desempenho das progénies de diferentes touros da raça Nelore no semiárido brasileiro. Informações de 741 animais foram coletadas de uma fazenda comercial localizada no municipio de Varzelândia-MG. Os animais eram filhos de 27 touros da raça Nelore e eram categorizados como LA (livro aberto) ou PO (puros de origem). Foram avaliados os dados de peso, ganho de peso médio diário e perímetro escrotal. As avaliações foram realizadas aos 12 (ano) e 18 (sobreano) meses de idade. Os dados foram analisados pelo método dos quadrados mínimos, utilizando um modelo que considerou efeito de categoria (LA ou PO), touro, anos, mês de nascimento e sexo dos bezerros. Houve influência significativa da categoria, sexo, mês de nascimento e touro sobre o desempenho dos animais até o ano, enquanto as características de desempenho ao sobreano foram influenciadas somente pelo mês de nascimento e touro (P<0,05). Sendo assim, os fatores do meio como ano e mês de nascimento e sexo do bezerro são importantes fontes de variação sobre o desempenho dos bezerros do nascimento até o sobreano, devendo, portanto, ser consideradas na comparação e seleção de animais com base nestas características.(AU)

Evaluation of scrotal temperature in different testicular shapes by infrared thermography in Braford bulls

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...