Evaluation of fertility and infertility in natural service bulls

Parkinson, TJ

doi:10.1016/j.tvjl.2003.10.017

Cited by 85 publications

(62 citation statements)

References 108 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A very good bull obtained 84.80% for pregnancy rate, but other questionable bulls obtained 86.67 and 96.55% at the end of the breeding season (Oliveira et al, 2007). Although libido and mounting capacity tests may not be sufficient to precisely determine potential pregnancy rates (Parkinson, 2004), it is possible to assert that the chances of obtaining good pregnancy rates are higher when bulls pass the three first steps of breeding soundness evaluation and show both presence of libido and mounting capacity.…”

Section: Resultsmentioning

confidence: 97%

Causes of rejection of beef bulls in breeding soundness evaluation

et al. 2012

View full text Add to dashboard Cite

-The objective of this study was to analyze the rates of rejection in the different steps of the breeding soundness evaluation of beef bulls in the state of Rio Grande do Sul, Brazil. The breeding soundness of 22,113 young and mature bulls of 14 beef breeds, participating in the Program of Reproductive Evaluation (PARTO) was evaluated in the experiment.Data concerning to the causes of rejection in the four steps of the breeding soundness evaluation (general physical examination, genital tract examination, semen evaluation and sexual behavior assessment) were analyzed by the Chi-square test and univariate regression analysis. According to year, general physical examination, genital tract examination and semen evaluation determined the rejection of 0.9% to 2.5%, 5.1% to 7.7%, 1.8% to 5.3%; and 4.2% to 6.7%, 7.3 to 9.3%, and 2.5% to 5.5% of young and mature bulls, respectively. Mature bulls presented higher chances of rejection than young bulls in the general physical examination in every year evaluated; as to the genital tract examination, their chances of rejection were higher in years I and II, but not in year III. In the semen evaluation, there was no difference between the ages assessed in any of the three years evaluated. Sexual behavior assessment accounted for the rejection of 1.9 to 6.0% of the young bulls and 2.9% to 3.9% of mature bulls, in accordance with the years evaluated; in years I and II, mature bulls presented higher rejection rates than young bulls. These results confirm the importance of performing all steps of the breeding soundness evaluation, including the sexual behavior assessment as a work routine, rather than an additional, optional stage of the evaluation, which should be carried out before the breeding season. The results indicate the relationship between bull age and rejection rate in the breeding soundness evaluation.

show abstract

Section: Resultsmentioning

confidence: 97%

Causes of rejection of beef bulls in breeding soundness evaluation

et al. 2012

View full text Add to dashboard Cite

show abstract

“…Pregnancy rate, which is strongly correlated with non-return rate, has also been proposed . Semen quality measures such as sperm concentration, motility and per cent live/dead are also often used to characterise male reproduction (Parkinson, 2004) but studies on their association with pregnancy rate in the field are contradictory (Parkinson, 2004). Testicular characteristics (e.g.…”

Section: Reproductive Phenotypes Used In Animal Breedingmentioning

confidence: 99%

Genetics and genomics of reproductive performance in dairy and beef cattle

Berry

Wall

Pryce

2014

Animal

321

235

View full text Add to dashboard Cite

Excellent reproductive performance in both males and females is fundamental to profitable dairy and beef production systems. In this review we undertook a meta-analysis of genetic parameters for female reproductive performance across 55 dairy studies or populations and 12 beef studies or populations as well as across 28 different studies or populations for male reproductive performance. A plethora of reproductive phenotypes exist in dairy and beef cattle and a meta-analysis of the literature suggests that most of the female reproductive traits in dairy and beef cattle tend to be lowly heritable (0.02 to 0.04). Reproductive-related phenotypes in male animals (e.g. semen quality) tend to be more heritable than female reproductive phenotypes with mean heritability estimates of between 0.05 and 0.22 for semenrelated traits with the exception of scrotal circumference (0.42) and field non-return rate (0.001). The low heritability of reproductive traits, in females in particular, does not however imply that genetic selection cannot alter phenotypic performance as evidenced by the decline until recently in dairy cow reproductive performance attributable in part to aggressive selection for increased milk production. Moreover, the antagonistic genetic correlations among reproductive traits and both milk (dairy cattle) and meat (beef cattle) yield is not unity thereby implying that simultaneous genetic selection for both increased (milk and meat) yield and reproductive performance is indeed possible. The required emphasis on reproductive traits within a breeding goal to halt deterioration will vary based on the underlying assumptions and is discussed using examples for Ireland, the United Kingdom and Australia as well as quantifying the impact on genetic gain for milk production. Advancements in genomic technologies can aid in increasing the accuracy of selection for especially reproductive traits and thus genetic gain. Elucidation of the underlying genomic mechanisms for reproduction could also aid in resolving genetic antagonisms. Past breeding programmes have contributed to the deterioration in reproductive performance of dairy and beef cattle. The tools now exist, however, to reverse the genetic trends in reproductive performance underlying the observed phenotypic trends.

show abstract

“…However, some improvement in semen quality occurs with advancing age [17]. Scrotal circumference (SC) and sperm motility and morphology are the traits most closely correlated with the fertility of bulls [7,15]. Moreover, measuring SC is particularly important in examination of yearling bulls, and it is highly correlated with sperm production and semen quality [3].…”

mentioning

confidence: 99%

Relationships Among Age, Body Weight, Scrotal Circumference, Semen Quality and Peripheral Testosterone and Estradiol Concentrations in Pubertal and Postpubertal Holstein Bulls

Devkota

Koseki

Matsui

et al. 2008

The Journal of Veterinary Medical Science

View full text Add to dashboard Cite

ABSTRACT. In the present study, the correlations among age, body weight, scrotal circumference (SC), semen quality and peripheral testosterone and estradiol-17β (E 2 ) concentrations were investigated in pubertal (n=5) and postpubertal (n=7) groups of Holstein bulls over a 6 week period. There were significant positive correlations (P<0.01) among age, body weight and SC in both groups, and similar significant correlations between sperm motility and SC in pubertal bulls (P<0.01) and between sperm concentration and SC in postpubertal bulls (P<0.05). The sperm motility after collection (P<0.05) and after freezing and thawing (P<0.01) of the postpubertal bulls correlated positively with the E 2 concentration. Estrogen may be important for the function of postpubertal bull testes, in which it may regulate spermatozoa motility in vivo. KEY WORDS: estrogen, postpubertal bull, sperm motility.J. Vet. Med. Sci. 70(1): 119-121, 2008 Early sperm collections from young bulls are often substandard in terms of sperm concentration, motility or morphology [9,12]. However, some improvement in semen quality occurs with advancing age [17]. Scrotal circumference (SC) and sperm motility and morphology are the traits most closely correlated with the fertility of bulls [7,15]. Moreover, measuring SC is particularly important in examination of yearling bulls, and it is highly correlated with sperm production and semen quality [3]. Bulls with an SC of 27.9 cm [14] or giving a first ejaculation with a total of 50 million sperm having at least 10% progressive motility after birth [12] can be considered to have reached puberty. Gonadotropins and gonadal steroids jointly regulate spermatogenesis and various other reproductive functions [2,12,19]. The emerging physiological roles of estrogens in male fertility have been considered recently in other animal species, particularly concerning the possible role of estrogens in functional regulation of efferent ductules and the epididymis [6,11], where sperm mature and acquire motility and fertilizing ability. Estradiol-17β (E 2 ) is also considered to be a germ cell survival factor in the human testis [16]. However, the precise role of estrogens in male animal reproduction in vivo is not clear. The aim of the present study was to investigate the relationships among age, body weight, SC, semen parameters and the peripheral concentrations of testosterone and E 2 in pubertal and postpubertal Holstein bulls.Twelve Holstein bulls that were 8.5 to 18.0 months of age and reared and kept at the National Livestock Breeding Center (NLBC), Niikappu Station, Japan, were randomly selected and subjected to weekly peripheral blood sampling for 6 weeks. Blood samples were collected at the same time every week, and plasma was harvested immediately at -30°C until assayed for testosterone and E 2 . The SC was measured once at the beginning of the experiment and again after 4 weeks, and the average SC was determined for each bull; this ranged from 22.5 to 34.2 (mean ± SEM: 30.6 ± 1.2) cm. Semen from these bulls was...

show abstract

Evaluation of fertility and infertility in natural service bulls

Cited by 85 publications

References 108 publications

Causes of rejection of beef bulls in breeding soundness evaluation

Causes of rejection of beef bulls in breeding soundness evaluation

Genetics and genomics of reproductive performance in dairy and beef cattle

Relationships Among Age, Body Weight, Scrotal Circumference, Semen Quality and Peripheral Testosterone and Estradiol Concentrations in Pubertal and Postpubertal Holstein Bulls

Contact Info

Product

Resources

About