Theileria orientalis Ikeda infection does not negatively impact growth performance or breeding soundness exam results in young beef bulls at bull test stations.

Introduction: Theileria orientalis Ikeda genotype is an emerging cattle disease in the US. Since 2017, when T. orientalis Ikeda was discovered in beef cattle in two counties in Virginia, cattle infections have risen to include ~67% of Virginia counties and 14 states. Consistent with New Zealand studies, many infected herds in Virginia were >90% positive upon initial testing without overt evidence of infection. Central bull tests present a unique opportunity to study the effects of T. orientalis Ikeda infections, as bulls from multiple source herds are consolidated. The objective of this study was to determine if infection with T. orientalis Ikeda affected the average daily gain (ADG), adjusted yearling weight (AYW) and breeding soundness of bulls at two test stations in Virginia over a period of years. Materials and methods: The bulls were fed and housed similarly to compare their growth performance and breeding soundness. For T. orientalis Ikeda testing, DNA was extracted from whole blood for quantitative polymerase chain reaction. Results: The number of bulls infected with T. orientalis Ikeda at initial delivery to the stations increased significantly over the years studied. Multivariable linear regression models, using Angus bulls from Virginia test stations, indicated no significant effect on ADG or AYW in bulls that became test positive during the test or were positive for the duration, compared to Angus bulls that were negative for the duration. At LOC A, the odds of passing a breeding soundness exam (BSE) were not significantly different for bulls that turned positive during the test or were positive for the duration, compared to bulls that were negative for the duration of the test. At LOC B, bulls that became positive during the test were 2.4 times more likely (95% CI: 1.165-4.995, p = 0.016) to pass their BSE compared to bulls that remained negative throughout the test. Discussion: We do not suppose that an obscured infection of T. orientalis Ikeda is protective for bulls to pass a BSE. However, this study demonstrates an obscured infection of T. orientalis Ikeda does not negatively affect weight gain or achievement of a satisfactory BSE rating at the central bull test stations in Virginia.

Does Size Matter? Testicular Volume and Its Predictive Ability of Sperm Production in Rams.

Over the years, testicular volume has been used to evaluate the reproductive capacity of rams and the effects of different factors related to reproductive performance. The aim of this study was to determine the most suitable tool and formula to calculate testicular volume under field conditions to guarantee a more accurate determination of sperm production. First, testicles from 25 rams (n = 50) were measured in vivo and postmortem using calipers and ultrasonography during the breeding season (BS). The accurate testicular volume (ATV) was calculated through water displacement. In addition, the sexual status of donor rams was evaluated during a period of four years in a reproduction center, and the three most crucial groups in terms of genetic value and seminal collections were studied in the second part of this experiment: ER-NBS (Elite rams during the non-breeding season), ER-BS-S (Elite rams with a standard frequency of seminal collection), and ER-BS-O (Elite rams with a high frequency of seminal collection). The total testicular volume (TTV), testosterone (T), and total spermatozoa obtained from two consecutive ejaculates in the same day (SPERM) were measured, and the relationship between SPERM and TTV and T was analyzed to predict SPERM. Although all published formulas revealed statistically significant differences (p ≤ 0.05) from the ATV, our proposed formula (ItraULE) (Testicular volume = L × W × D × 0.61) did not show significant differences. In the second part of the study, in the ER as a model donor ram for its high genetic value and high demand from farmers, TTV and T showed strong positive correlations with SPERM (r = 0.587, p = 0.007 NBS; r = 0.684, p = 0.001 BS-S; r = 0.773, p < 0.0001 BS-O). Moreover, formulas were established to predict SPERM in these practical scenarios. In conclusion, the use of ultrasonography and a new formula adapted to rams could improve the prediction of SPERM considering crucial factors such as season and semen collection frequency.

Novel interpretation of sperm stress test and morphology for maturity assessment of young Norwegian Red bulls.

The use of genomic selection significantly reduces the age of dairy bulls entering semen production compared to progeny testing. The study aimed to identify early indicators that could be used for screening bulls during their performance testing period and could give us insight into their future semen production performance, acceptance for the AI station, and prediction of their future fertility. The study population consisted of 142 young Norwegian Red bulls enrolled at the performance test station, followed until we received semen production data, semen doses, and, subsequently, non-return rates (NR56) from the AI station. A range of semen quality parameters were measured with computer-assisted sperm analysis and flow cytometry from ejaculates collected from 65 bulls (9-13 months). The population morphometry of normal spermatozoa was examined, showing that Norwegian Red bulls at 10 months of age have homogenous sperm morphometry. Norwegian Red bulls could be separated into 3 clusters according to their sperm's reaction patterns to stress test and cryopreservation. Results of semi-automated morphology assessment of young Norwegian Red bulls showed that 42% of bulls rejected for the AI station and 18% of bulls accepted had ejaculates with abnormal morphology scores. For the youngest age group at 10 months, the mean (SD) proportion of spermatozoa with normal morphology was 77.5% (10.6). Using novel interpretation of sperm stress test combined with sperm morphology analysis and consecutive cryopreservation at a young age allowed identification of the candidate's sperm quality status. This could help breeding companies introduce young bulls earlier to the AI stations.

Lesions of the prepuce and penis in rams: A retrospective study.

In the ovine reproductive management, a thorough breeding soundness evaluation including specific inspection of the male genital tract represents a valuable tool for assessing the reproductive potential of a selected subject and for diagnosing genital disorders. During examination, accurate inspection on penis and prepuce is necessary, since conditions affecting these structures may hamper regular coitus. Records from 1270 males undergoing breeding soundness evaluation (n = 1232) or admitted for genital disorders to the Section of Obstetrics and Gynaecology (n = 38) of the Department of Veterinary Medicine, were collected, and lesions of penis and prepuce were therefore classified. The data collected revealed that 47/1270 rams examined presented lesions of the penis and prepuce. The most frequent condition was urolithiasis accounting for over 2% of the cases, followed by lack of the urethral process (0.39% incidence), lack of the glans penis and hypospadias (0.23% cases). Moreover, most of the conditions (40%) were observed in animals less than 2 years old, suggesting the importance of a careful breeding soundness evaluation in animals at young age.

Semen Quality of the First and Second Ejaculates Collected from Breeding Inactive Stallions after Cooling and Freezing.

This study aimed to assess the semen quality after the cooling and freezing of the first and second ejaculates of the season, which were collected 1 h apart. After collection (n = 40 ejaculates), the gel-free semen volume, concentration, total number of sperm, and sperm morphology were determined. An aliquot of each ejaculate was extended and cooled for 48 h; a second aliquot was cushion-centrifuged and cooled for 48 h; and a third aliquot was processed and then frozen. The total motility (TM) and progressive motility (PM), plasma membrane integrity (PMI), and high mitochondrial membrane potential (HMMP) were assessed pre-(0 h), 24 h, and 48 h post-cooling and before and after freezing. The second ejaculate had a lower gel-free semen volume (p = 0.026). The sperm concentration was greater in the first than in the second ejaculate (p < 0.001). The sperm morphology was similar between the ejaculates (p > 0.05). Cushion-centrifugation prevented a reduction in the TM, PM, and PMI over time (p < 0.05). The TM, PM, and PMI decreased after freezing but not between the ejaculates (p > 0.05). The first and second ejaculates of the season, which were collected 1 h apart, varied in quantity but not in quality after cooling and freezing.

Association between body condition score, testicular haemodynamics and echogenicity, nitric oxide levels, and total antioxidant capacity in rams.

Higher body fatness adversely affects metabolic and hormonal homeostasis. The present work aimed to evaluate the association between body condition score (BCS) and haemodynamic pattern and echogenic appearence of the testes as well as nitric oxide (NO) levels and total antioxidant capacity (TAC). For that, fifteen Ossimi rams were blocked according to their BCS into a lower BCS group (L-BCS:2-2.5; n = 5), medium BCS group (M-BCS:3-3.5; n = 5), and higher BCS group (H-BCS:4-4.5; n = 5). Rams were examined for testicular haemodynamics (TH; Doppler ultrasonography), testicular echotexture (TE; B-mode image software analysis), and serum levels of NO and TAC (colorimetric). Results are presented as means ± standard error of the mean. There was a significant (P < 0.05) difference in the resistive index and pulsatility index means among the groups under experimentation, being the least in the L-BCS group (0.43 ± 0.02 and 0.57 ± 0.04, respectively) compared to the M-BCS (0.53 ± 0.03 and 0.77 ± 0.03, respectively) and H-BCS rams (0.57 ± 0.01 and 0.86 ± 0.03, respectively). Among blood flow velocity measurements [peak systolic, end-diastolic (EDV), and time-average maximum], only EDV showed significant (P < 0.05) higher values in the L-BCS group (17.06 ± 1.03 cm/s) compared to M-BCS (12.58 ± 0.67 cm/s) and H-BCS (12.51 ± 0.61 cm/s) groups. Regarding the TE results, there were no significant differences among the examined groups. There were significant differences (P < 0.01) in the concentrations of TAC and NO among the groups under experimentation, in which the L-BCS rams had the highest levels of TAC and NO in their sera (0.90 ± 0.05 mM/L and 62.06 ± 2.72 µM/L, respectively) than the M-BCS (0.058 ± 0.05 mM/L and 47.89 ± 1.49 µM/L, respectively) and H-BCS rams (0.45 ± 0.03 mM/L and 49.93 ± 3.63 µM/L, respectively). In conclusion, body condition score is associated with both testicular hemodynamic and the antioxidant capacity in rams.

Aniline blue test for sperm protamination-a valuable add-on to the bull breeding soundness evaluation.

Bull breeding soundness evaluation (BBSE) is the most common procedure used to predict bull potential fertility. However, the use of traditional methods for semen evaluation can affect its reliability. The inclusion of additional advanced test in BBSE may increase its accuracy. This study aimed to investigate the correlation between the degree of sperm protamination and BBSE main parameters of scrotal circumference (SC), progressive motility (PM), morphologically normal sperm (NS), and different categories of morphological defects. In addition, to determine the correlation between the three methods used for protamine assessment, five Brangus bulls were subjected to the BBSE. Semen samples were collected via electro-ejaculation and evaluated using traditional methods. Three different methods were used to determine the degree of sperm protamination: aniline blue (AB) staining, chromomycin A3 staining with fluorescent microscope (CMA3-FLM), and CMA3 with flow cytometry (CMA3-FCM). Sperm protamine deficiency assessed using the three methods exhibited significant differences among bulls according to their classification by BBSE, and showed significant negative correlation with semen quality parameters of NS and PM. A significant positive correlation was found between AB positivity and morphological abnormalities. The three methods used for protamine assessment also revealed significant positive correlations. Among the three tests, AB staining was the cheapest and easiest test that offers an objective assessment method for sperm protamination. Hence, it can be concluded that the assessment of protamination using AB staining test might serve as an additional valuable parameter or a replacement whenever detail sperm motility and morphology analyses in conducting BBSE to predict bull fertility are not possible.

Associations between insulin-like factor 3, scrotal circumference and semen characteristics in young Norwegian Red bulls.

With the integration of genomic selection in the cattle artificial insemination (AI) industry, bulls are selected for their semen production capacity and fertility at a younger age than previously. Norwegian Red bull calves selected as candidates to become future AI bulls based on their genomic breeding value are kept in a performance testing station from around the age of 3-12 months, allowing for sample collection and analysis of different parameters during their pre- and peripubertal period. Insulin-like factor 3 (INSL3) is a small peptide hormone specifically secreted by the mature Leydig cells of the testes. In the foetus, it induces the first phase of testicular descent and is considered to reflect Leydig cell development during puberty; it could therefore be an interesting early indicator of future semen production capacity. The main objective of our study was to evaluate the relationship between INSL3, scrotal circumference (SC), and semen characteristics. This is the first time INSL3 was measured in the Norwegian Red population. We collected blood samples for analysis of INSL3 from 142 Norwegian Red bulls at the performance testing station and measured their SC on the same day. Altogether, measurements were made at four time points: upon arrival at the performance testing station (quarantine (Q): 2-5 months) and later at approximately 6, 9 and 12 months of age. Information on season and place of birth were made available from the database of the breeding company Geno, together with data on semen characteristics from the test station and the AI station. The median SCs for age groups Q, 6, 9, and 12 were 15, 21.5, 29, and 34 cm, respectively. INSL3 was shown to be positively correlated with SC (R = 0.4) but not with any of the semen characteristics. Similarly, we found no correlation between SC and sperm characteristics from data on ejaculates analysed at the performance testing station and AI station. The mean sperm volume for the 31 selected bulls with at least 10 ejaculates produced in the AI station increased from 2.3 ml at the performance testing station to 6.4 ml at the AI station. The corresponding increase in mean sperm concentration was from 497 million/ml to 1 049 million/ml. We conclude that INSL3 exhibits high inter-individual variability in the Norwegian Red bull population, which cannot be explained by the parameters measured in this study. At present, INSL3 cannot be used as a biomarker of sperm production in this breed.

Diagnostic tests in canine andrology - What do they really tell us about fertility?

Dog breeders often require breeding soundness evaluations which include andrological examinations of the genital organs, hormone measurements, and semen analyses. During the past decades, a considerable number of research results have been published, allowing diagnoses of specific andrological conditions and fertility assessment. For specific examinations, however, no standard procedures have been defined and for some parameters different reference ranges have been published. Therefore, examination results from different facilities are difficult to compare and profound conclusions regarding health and fertility of a male dog are not always possible. Conventional semen examination, however, is still useful in identifying deviations or no deviations from normality, especially if confounding factors are taken into account and if the exam is repeated in case of inconclusive findings. A standardization of examination procedures and reference ranges would help to harmonize the exchange of examination results and interpretation of the findings.

Chronic ergot exposure in adult bulls suppresses prolactin but minimally impacts results of typical breeding soundness exams.

Canadian standards allow ≤3000 µg ergot alkaloids/kg cattle feed. A concentration-response relationship was hypothesized between ergot in feed and reductions in plasma prolactin, sperm motility, sperm function, and increase in sperm abnormalities. The study consisted of pre-treatment (12 weeks), treatment (9 weeks), and post-treatment periods (10 weeks). Adult bulls were fed 1113 (n = 8; low ergot group) or 2227 (n = 6; high) µg/kg of dry matter intake. Endpoints were measured every two weeks. Ejaculates were analyzed for sperm concentration, total and progressive motility, plasma membrane and acrosome integrity, mitochondrial membrane potential and sperm abnormalities. Data were analyzed by repeated measures MIXED PROC in SAS. Average outside ambient temperature during the pre-treatment, treatment, and post-treatment periods was -13 (-31 to 1), 0.5 (-18 to 19), and 21 (13-28) °C. Plasma prolactin decreased markedly during treatment (-52.4%; Experimental period p < 0.01). Rectal temperature increased during the treatment and post-treatment periods (EP p < 0.01) but was within the normal physiological range. Bull weight increased during the study (EP p < 0.01). Scrotal circumference in low ergot group increased during treatment (+0.8 cm; Tx∗EP p = 0.05). Progressive motility in high ergot group decreased during treatment (-7%; Tx∗EP p = 0.05), however, semen volume and sperm concentrations were unaffected (p ≥ 0.11). Live sperm with high and medium MMP decreased during treatment (-1.4 and -3.7%; EP p < 0.01). Results suggest that feeding ≤2227 µg ergot alkaloids/kg has only minor effects on adult bull semen quality.

Satisfactory breeding potential is transiently eliminated in beef bulls with clinical anaplasmosis.

BACKGROUND: Natural service breeding is common in U.S. cow-calf operations. Diseases impacting bull reproductive performance have significant economic consequences for producers. Anaplasmosis may be an underappreciated cause of poor reproductive performance in bulls. The primary systemic effects of bovine anaplasmosis including anemia, fever, and weight loss, can all result in unsatisfactory reproductive performance. The objective of this pilot study was to evaluate breeding soundness examination (BSE) outcomes and clinical changes in bulls during and upon resolution of clinical anaplasmosis. Anaplasma marginale-challenged bulls were observed for clinical disease and infection progression and changes in breeding soundness compared to uninfected control bulls for 16 weeks. RESULTS: All Anaplasma marginale-challenged bulls were PCR-positive, seropositive, and showed clinical signs by 3-, 17-, and 24-days post-challenge, respectively. Clinical signs of anaplasmosis included pallor, icterus, fever (≥ 40.2 °C), and weight loss. Acute anemia was observed in all challenged bulls with PCV nadirs ≤ 18% and peak percent parasitized erythrocyte ≥ 50%. Decreased scrotal circumference and poor semen quality (e.g., increased percentage of abnormal spermatozoa, decreased progressively motile sperm), were initially observed within days after onset of clinical anaplasmosis signs and continued weeks beyond disease resolution. Control bulls remained negative for A. marginale. CONCLUSION: This pilot study demonstrates that clinical anaplasmosis reduces breeding soundness in beef bulls. Anaplasmosis should be considered as a differential for bulls with decreased semen quality, especially within endemic areas. A 90 day or greater retest window is recommended for bulls of unsatisfactory breeding potential recently recovered from clinical anaplasmosis.

Environmental Factors Affecting the Reproductive Efficiency of Italian Simmental Young Bulls.

The objectives of the study aimed to evaluate the effect of weather conditions and scrotal circumference (SC) on standard semen characteristics of Italian Simmental young bulls (n = 577), all raised in the same performance station and sampled by the artificial vagina (AV) method. Considering the increasing SC, the results showed a significant increase in quantitative semen parameters (p < 0.05 and p < 0.0001, for sperm concentration and total number of spermatozoa, respectively); for every extra centimeter of SC, 17.5 × 106 spermatozoa/mL and 0.102 × 109 of total spermatozoa were produced. The age of the animal at semen collection (395 and 465 days) had similar positive effects. The effect of the average temperature humidity index (THI limits ≤ 40 and ≥70) in the previous 60, 30, and 10 days before the semen collection was also considered. Sixty days before the semen collection, the increasing THI increased both primary (p < 0.0001) and secondary (p < 0.0001) abnormalities while the percentage of morphologically normal spermatozoa decreased (p < 0.0001). Thirty and ten days before collection, the same effect on morphological traits was maintained, but total and progressive motility was also influenced (p < 0.01) with an unexpected increasing pattern. Thus, environmental conditions can influence semen quality during the entire spermatogenesis and results can guide future research on this breed.

Effect of lameness on breeding soundness examination results of beef bulls.

Studies suggest that high cortisol resulting from lameness-associated pain decreases testosterone and disrupts spermatogenesis leading to decreased fertility. The objective of this study was to investigate the effect of lameness on cortisol and testosterone concentrations and breeding soundness examination of beef bulls presented to a veterinary teaching hospital. Bulls, two-years of age or older, that presented for lameness, foot trim, and/or breeding soundness examination were enrolled. Blood samples were collected for cortisol and testosterone evaluation. A complete breeding soundness examination (BSE) was performed in all bulls. Subsequently, a complete lameness examination was performed, and limb/foot lesions recorded. A blinded evaluator used a lameness score of 1-5 to classify each bull as lame (>1) or not-lame (1). A total of 60 bulls were enrolled (34 with a satisfactory BSE and 26 with an unsatisfactory BSE result). Cortisol and testosterone were not different between the unsatisfactory and satisfactory groups (P = 0.26 and 0.32, respectively). The most common limb/foot lesions found in the unsatisfactory and satisfactory groups were laminitis-related (61.50% and 41.20%, respectively). There was no difference in the proportion of lame and not-lame bulls in the unsatisfactory and satisfactory groups (P = 0.17). The odds of a satisfactory BSE result were 4.40 times higher in not-lame bulls when compared with lame bulls. Therefore, lameness is associated with an unsatisfactory BSE result in beef breeding bulls.

Breeding soundness examination (BSE): a decision-making tool that requires a particular guideline for male goats.

Breeding soundness examination (BSE) is a common evaluation to predict the reproductive ability of male livestock. The generated guideline for BSE is specified for each animal species to enhance the performance of BSE. However, there is no particular BSE guideline for bucks yet; then, the BSE guidelines for ram and bull are commonly used for bucks. This investigation was conducted to determine the main BSE characteristics and the appropriate age range for assessment in Boer goats. For this purpose, semen was collected using electro-ejaculation, and seminogram variables (semen-BSE traits) were evaluated using conventional methods. The association between common testicular biometric variables (TBVs) and semen-BSE traits were assessed using Pearson's correlation coefficients and multiple linear regression. Logistic regression was used to test the validity of TBVs for the BSE of Boer goats. In this study, a strange appearance of the head of sperm, known as "rod-in-head" (RIH), was observed. The results showed that the appropriate age range for performing BSE in bucks is 12-30 months. Moreover, scrotal length in the range of 10-15.9 cm was the eligible TBV to be used as a predictor for semen-BSE traits. It was suggested that developing a BSE guideline for bucks is necessary for unbiased selection in performing BSE.

Ageing affects plasma steroid concentrations and testicular volume, echotexture and haemodynamics in rams.

The objective was to determine the effect of ageing on plasma steroid concentrations and testicular volume, echotexture and haemodynamics in Ossimi rams. Twenty-four rams were allocated, by age, into three groups: young (1 year; 32.00 ± 0.78 kg, n = 6); mature (2.5 years; 48.00 ± 1.02 kg, n = 9) and aged (7.5 years; 65.00 ± 1.10 kg, n = 9). Aged rams had the highest (p Ë‚ 0.05) plasma testosterone concentrations 3.90 ± 0.75 ng/ml (three-fold the other groups), whereas in young rams, plasma estradiol-17ß concentrations (5.85 ± 0.34 pg/ml) were approximately one-quarter (p Ë‚ 0.05) of other groups. Regarding pulsed-wave Doppler indices values of the (resistive index RI; and pulsatility index PI) were lower (p Ë‚ 0.05) in the mature (0.32 ± 0.04 and 0.36 ± 0.03, respectively) and aged (0.51 ± 0.03 and 0.77 ± 0.06) rams compared to young rams (0.62 ± 0.03 and 0.98 ± 0.07). In the young group, testicular pixel intensity was highest (p Ë‚ 0.05) but values of coloured area/pixels were lowest (p Ë‚ 0.05) compared to the other groups. In conclusion, these parameters indicate that aged rams (7.5 years) are likely to be suitable for breeding ahead of the younger aged groups (1 and 2.5 years) examined, but a final decision would need to be tempered by consideration of other parameters in the breeding soundness examination (BSE), such as physical soundness and semen characteristics. Of the parameters studied, testicular pixel intensity could be most readily incorporated in a BSE for deciding a ram's breeding efficiency.

Reproductive Management of Rams and Ram Lambs during the Pre-Breeding Season in US Sheep Farms.

In sheep farms, achieving economic and productive efficiency and sustainability goals is directly related with the reproductive management of the animals. Genetically, the male contribution to the offspring is 50%, but in practical terms, there is a greater potential impact of the ram on reproductive results, because one male has the potential to affect a large group of females and therefore greatly affects the entire flock. Unfortunately, the selection of males for breeding in the US sheep industry has been traditionally conducted based on phenotypical traits, without a genetic/reproductive evaluation, and/or health assessment or records. Therefore, it is important to establish integrative management practices to select the rams and ram lambs to be used in the breeding season. Among these practices are genomic testing, a comprehensive breeding soundness evaluation and assessment of health status and records of the males before the breeding season, to detect and correct potential issues.

Shade availability on pasture does not affect semen characteristics of Brahman bulls (Bos taurus indicus).

Testicular degeneration by heat is the leading cause of infertility in bulls. Beef cattle are generally farmed under hot and humid conditions, and consequently, the thermotolerance of each breed must be considered in their natural environment. This study aimed to evaluate the reproductive characteristics of Brahman bulls maintained in the grazing system, with or without shadow availability. Ten Brahman bulls aging between 24 and 30 months were allocated in two different paddocks, with or without shadow availability. The heat tolerance test was performed on three non-consecutive typical summer days. The semen samples were collected at four times points in a 14 days interval. The climate conditions were monitored throughout the experiment; and clinical evaluation, testicular consistence and scrotal circumference were measured before every semen collection. In addition, semen was evaluated regarding volume, aspect, turbulence, motility, straight movement, sperm concentration, and morphological exam. The studied Brahman bulls showed a high thermolysis capacity, high heat tolerance, and no differences in semen quality were observed between groups.

A degeneração testicular causada pelo calor é a principal causa de infertilidade em touros. Bovinos de corte geralmente são criados em condições de calor e umidade, e, consequentemente, a termotolerância de cada raça deve ser considerada em seu ambiente natural. O presente trabalho teve como objetivo avaliar as características reprodutivas de touros da raça Brahman mantidos em sistema de pastejo, com ou sem disponibilidade de sombra. Dez touros Brahman com idades entre 24 e 30 meses foram alocados em dois piquetes diferentes, com ou sem disponibilidade de sombra. O teste de tolerância ao calor foi realizado em três dias típicos de verão não consecutivos. As amostras de sêmen foram coletadas em quatro momentos em intervalos de 14 dias. As condições climáticas foram monitoradas durante todo o período experimental; e a avaliação clínica, consistência testicular e a circunferência escrotal foram avaliadas antes de cada coleta de sêmen. Ainda, o sêmen foi avaliado quanto ao volume, aspecto, turbulência, motilidade, vigor, concentração espermática e exame morfológico. Os touros estudados da raça Brahman apresentaram alta capacidade de termólise, alta tolerância ao calor, e não foram observadas diferenças na qualidade do sêmen entre os grupos.

New Approaches to Assess Fertility in Domestic Animals: Relationship between Arterial Blood Flow to the Testicles and Seminal Quality.

The early identification of infertile males improves reproduction efficiency at a production level and is essential to secure high production rates. Before entering a breeding program, males must pass an initial breeding soundness examination (BSE) which consist of several diagnostic exams whose end point is to estimate their future fertility. There is ongoing research to find new markers that allow better identification of fertile males. Doppler mode allows the quantitative and qualitative evaluation of the irrigation of organs. When evaluating the reproductive system, Doppler mode has been successfully used for the evaluation of the uterine and ovarian irrigation. In males, it is gaining relevance for the evaluation of testicular irrigation. Researchers have found a relationship between pulsed-wave Doppler velocimetric parameters and seminal quality in various domestic animal species. This suggests Doppler ultrasound parameters should be considered as objective parameters to evaluate testicular function. In this review, we analyze the results in the main domestic animal species and discuss the differences and similarities among the results. We also discuss the effect of the location of the measurements, breed, season and laterality in the measurement of Doppler velocimetric parameters as well as the impact and limitations of this method of assessing breeding soundness.

Efeito de diferentes concentrações de ingestão de gossipol livre sobre morfometria testicular e qualidade seminal de touros da raça Nelore / Effect of free gossypol intake in different levels on the testicular morphometry and seminal quality of Nelore bulls

A cotonicultura tem forte fator de impacto na economia nacional, e o estado de Mato Grosso se destaca por ser o maior produtor de algodão herbáceo e deter o maior rebanho bovino do país, condições essas que estimulam o uso do caroço, da torta e do farelo de algodão na alimentação animal. Considerando que o gossipol está presente nos subprodutos do algodão e que seus efeitos sobre a reprodução podem reduzir a fertilidade dos animais, objetivou-se, com essa pesquisa, avaliar o efeito da ingestão de dietas com diferentes teores de gossipol livre por dia sobre a morfometria testicular e a qualidade seminal de touros da raça Nelore. Foram utilizados 28 touros, distribuídos aleatoriamente em seis tratamentos: T0, 0 grama de gossipol livre/touro/dia ; T1, 1,08 grama de gossipol livre/touro/dia; T2, 2,07 gramas de gossipol livre/touro/dia; T3, 3,24 gramas de gossipol livre/touro/dia; T4, 3,82 gramas de gossipol livre/touro/dia e T5, 5,08 gramas de gossipol livre/touro/dia. Os animais de cada tratamento foram mantidos confinados em área média de 100m2, dotada de bebedouro, cochos para mistura mineral e para volumoso/concentrado. O consumo de 3,24 gramas de gossipol livre/touro/dia alterou a qualidade espermática e a morfometria testicular de touros.(AU)

The cotton industry has a strong impact factor in the Brazilian economy and the state of Mato Grosso stands out for being the largest upland-type cotton producer and also holds the largest cattle herd in the country, conditions that stimulate the use of cottonseed pie and cottonseed meal in animal feed. Whereas gossypol is present in cotton by-products and their effects on reproduction can reduce the animal fertility, this research evaluated the effect of diets with different free gossypol contents in the testicular morphometry and semen quality of Nelore bulls. 28 bulls were randomly distributed in six treatments: T0, receiving no free gossypol; T1, receiving 1.08g / bull / day; T2, receiving 2.07g / bull / day; T3, receiving 3.24g / bull / day; T4, receiving 3.82g / bull / day and T5, receiving 5.08g / bull / day of free gossypol respectively. The animals in each treatment were kept confined in an averaged area of 100m2, having fresh water, troughs for mineral mixture and roughage / concentrate. The consumption of 3.24g of free gossypol / bull / day altered the bulls sperm quality and testicular morphometry.(AU)