SEARCH · PubMed Health

Results for “semen production trait”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

12 recordsLinked to original sources

PubMed2026

Genomic inbreeding coefficients and inbreeding depression of semen production traits at genome-wide and chromosomal levels in Japanese Holstein bulls.

We aimed to estimate inbreeding coefficients and the effects of inbreeding depression on semen production traits at both the genome-wide and chromosomal levels. We utilized pedigree data for 19,921 animals, single nucleotide polymorphism (SNP) data on 5700 Japanese Holstein bulls, and 52,193 semen collection records from 775 bulls. We estimated 4 different inbreeding coefficients, namely a pedigree-based coefficient (FPED) and 3 genomic coefficients derived from SNP data. The genomic coefficients consisted of one based on the genomic relationship matrix (FGRM), one based on runs of homozygosity (ROH), and one based on homozygous-by-descent (HBD) segments (FHBD). These genomic coefficients were estimated at both the genome-wide and chromosomal levels. Furthermore, we investigated the effects of these coefficients on semen production traits: semen volume (VOL), sperm concentration (CON), sperm number (NUM), and sperm motility (MOT). In the genome-wide-level analysis, inbreeding coefficients increased markedly in bulls born after 2009, coinciding with the introduction of genomic selection. Significant inbreeding depression of VOL was found. At the chromosomal level, the inbreeding coefficients for most chromosomes showed a similar trend to the genome-wide metrics, although some (e.g., chr10 and chr20) exhibited a more pronounced trend. Suggestive inbreeding effects were detected on specific chromosomes for all traits (chr1 and chr22 for VOL, chr24 and chr29 for CON, chr1, chr12, and chr27 for NUM, chr10 and chr18 for MOT), including the traits that were not significant at the genome-wide level. Our results highlight that chromosomal-level analysis provides information complementary to whole-genome metrics, offering a more detailed perspective for managing inbreeding effects. To mitigate the adverse effects of inbreeding on semen production traits, future breeding programs would benefit from the control of inbreeding effects on high-risk chromosomal regions.

Genomic inbreeding coefficient↗

PubMed1988

Semen traits and fertility of White Leghorn males shown to be positive or negative for lymphoid leukosis virus in semen and feather pulp.

1. Males from strains selected for high egg production (and other economic traits) and from unselected control strains were used to determine the frequency of shedding of lymphoid leukosis virus (LLV) into semen. The effect of the male's LLV status on semen production, fertility and hatchability was also examined in males of the unselected control strains. 2. The frequency of detection of exogenous LLV in semen by the phenotypic mixing test, and high concentrations of the viral group specific antigen in feather pulp by the complement fixation test, were both higher in control strains than in strains selected for high egg production. 3. Semen production was not reduced in LLV-shedding males. 4. Significant associations of LLV shedding with higher incidence of abnormal spermatozoa and reduced fertility were found in some populations but not in others. No significant effect of LLV shedding on hatchability was detected. 5. Tests for group specific antigen in feather pulp proved useful in identifying males that shed LLV in semen.

Animals↗

PubMed1985

Ram management for northeastern flocks.

The ram is an important member of the flock, particularly in smaller, intensively managed flocks such as are found in the Northeast. An infertile ram can spell reproductive and financial failure for the producer. A highly fertile ram can settle more ewes in a shorter time, produce more twins, and confer valuable traits on his offspring. These include wool type, rate of gain and higher sperm production and ovulation rates. Details of the breeding soundness examination, including semen evaluation are discussed. Ram management techniques appropriate for Northeastern sheep producers are presented.

Animal Husbandry↗

PubMed1990

The effect of tamoxifen on sexual puberty of turkey toms and Muscovy drakes.

The effects of Tamoxifen (TAM) on reproductive traits in young turkey toms and Muscovy drakes were studied. At 6 wk of age, five toms were injected every other day with 1 mg TAM/kg BW, while six others were treated with corn oil (controls). In the toms, using TAM advanced semen production by 4 wk (13.5 versus 17.5 wk of age) and increased the size of the snood and testes. Similarly, in the Muscovy drake, using TAM enhanced penis growth and advanced semen production by 5 wk.

Animals↗

PubMed1989

Role of the basomedial hypothalamus in regulation of adiposity, food intake, and reproductive traits in the domestic fowl.

Bilateral basomedial hypothalamic (BMH) electrolytic lesions in White Leghorn cockerels produced six main physiological categories characterized by typical sets of symptoms: 1) functional castration (FC); hyperphagia, obesity, occasional diabetes insipidus, involuted adenohypophysis, dwarfism, atrophied comb and testes, reduced hematocrit, reduced plasma testosterone and thyroid activity, involuted thymus and adrenal cortex and elevated liver fat and plasma triglycerides and free fatty acids. The FC birds demonstrated defective immune response for the first 12 to 16 wk post-surgery. 2) functional castration with large comb (FCLC); hyperphagia, obesity, transient diabetes insipidus, slight diminution of adenohypophy-seal weight with marked reduction in basophilic cell population, fully atrophied testes but only slight reduction in comb size and hematocrit, plasma testosterone levels between those found in the first category and the control. 3) obese with normal testes (ONT); hyperphagia, obesity, high level of plasma lipids, normal histological organization of the adenohypophysis, normal testes, semen production and comb size. The next three categories exhibited physiological syndromes identical to the former three categories except for food intake, which operationally could be defined as normal. A marked difference among the BMH-lesioned birds was found in sexual behavior when the FC birds completely lost their libido. None of the replacement therapy regimens caused complete rehabilitation from adiposity or restoration of reproductive traits. Lipoprotein lipase activity increased at an early stage postlesioning and preceeded the development of hyperphagia. Placement of BMH lesions in newly hatched chicks resulted in marked dwarfism and obesity without hyperphagia. The BMH-lesioned heavy breed White Rock cockerels exhibited a lesser degree of adiposity than the light White Leghorn birds. Removal of the olfactory bulbs and destruction of the septal area resulted in increased thyroid activity, with secondary hyperphagia without obesity. In a short-term study, administration of sodium pentobarbital to the BMH area resulted in increased feeding. Conversely, glucose administration to the same area suppressed feeding in satiated but not in food-deprived chickens.

Adipose Tissue↗

PubMed1989

The effect of tamoxifen on the reproductive traits in White Leghorn cockerels.

Fifty White Leghorn male chicks were divided into five equal groups of ten chicks each. Beginning at two weeks of age they were injected on each alternate day as follows: corn oil as a vehicle control or 0.5, 1.0, 5.0, or 10.0 mg tamoxifen/kg/b.wt. The whole experimental period lasted until twelve weeks of age. The two lowest doses of tamoxifen (TAM) enhanced comb growth, while the highest dose suppressed it. The two lowest doses of TAM also caused an earlier increase in sexual activity of the chicks, and precocious production of semen. At nine weeks of age the 0.5 and 1.0 mg doses of TAM increased plasma testosterone to a level three times higher than in the controls. This effect was not observed with the highest dose of TAM. At 12 weeks of age the chicks treated with 1 mg TAM had larger testes than the controls and produced three times more sperm per ejaculation. At this stage chicks treated with the highest dose of tamoxifen produced less sperm than the control and had smaller testes and adenohypophyses.

Aging↗

PubMed1991

Expert system for evaluation of reproductive performance and management.

A microcomputer expert system for dairy herd reproductive management was developed using an expert system shell and Turbo Pascal. The expert system initially examines the broad areas of days open, days to first breeding, detection of estrus, and conception rate to determine whether a problem exists. Interpretations ranging from "excellent" to "severe" were established for each trait. The system then selects an area for evaluation that has the largest negative influence on days open. Once an area has been selected for further evaluation, the expert system utilizes information from the user and DHI reports developed by the Dairy Records Processing Center in Raleigh, NC. These reports identify problems with conception categorized by production, parity, service number, days in milk, breed, and service sire. In addition, questions are presented by the expert system to isolate problems of accuracy of data, use of natural service, semen handling, AI technique, detection of estrus, signs of estrus, and other management areas. Recommendations and suggestions are given. Ten commercial herds having a conception rate less than 40% were evaluated by the expert system and by an extension reproduction specialist who supplied information for the system. Of 100 areas investigated, the expert system and extension specialist identified 47 as potential problem areas, agreeing on 85% of them. Most discrepancies resulted from the specialist applying a less restrictive standard when values were close to a preselected threshold.

Animal Husbandry↗

PubMed1991

Some nutritional and genetic considerations in the performance testing of beef bulls.

Performance testing started after it was recognized that growth traits were heritable. In the early years of performance testing there was a tendency to feed higher levels of energy for longer periods of time. More recently, the trend has been to feed lower levels of energy for shorter periods. There are still differences in opinion as to the appropriate level of energy to use. Although it is important that the level of energy fed is adequate to correctly establish a bull's ability to gain, it is essential to know that it will pose no risk of impaired spermatogenesis or cause any degree of laminitis. Clinical observations and research on overfeeding clearly show that both libido and spermatogenesis can be impaired by excess energy intake. The damage in 2-year-old bulls can be very extensive and in some animals it may not be reversible. The scant amount of research in yearling bulls indicates that there is considerable potential danger from overfeeding energy as well. Test stations are under used in regard to performing research that would help identify heritable defects that would interfere with the productive and reproductive efficiency of beef cattle. The first performance testing programs emphasized average daily gain from weaning to 1 year of age, so "performance" has traditionally meant rate of gain to most cattle raisers. The term "performance" is now starting to acquire a broader and more inclusive definition. For many breeders, it now includes weight per day of age, which is in part a maternal trait, and some kind of male evaluation for reproductive potential that can also be extrapolated to the female side. One of the first breakthroughs in this regard was to recognize the heritability of testicular size, and that testicular size could be fairly accurately determined by scrotal circumference measurement. It was also found that there was a favorable relationship between larger testicle size and the ability to produce high quality semen. As a result, it became a common practice to include scrotal circumference measurements in the published bull test results. However, many test station patrons were, and still are, content to consider the scrotal circumference measurement alone as an evaluation of a bull's breeding potential. Unfortunately, less than half of the bulls finishing a performance test at ages ranging from 11 to 14 months will be able to produce semen of completely acceptable quality.(ABSTRACT TRUNCATED AT 400 WORDS)

Animal Nutritional Physiological Phenomena↗

PubMed1990

Effect of season on seminal traits and serum hormone concentrations in captive male Siberian tigers (Panthera tigris).

Electroejaculates and serum samples were collected throughout the year from 5 male Siberian tigers. Semen quality, seminal plasma chemistry and serum hormone concentrations were evaluated and analysed as a function of season. Semen volume, concentration, motility, viability and morphology were not influenced by season. The ability of spermatozoa to undergo capacitation and penetrate zona-free hamster eggs did not differ due to season. Season had no influence on seminal plasma concentrations of acid phosphatase, calcium, glucose, potassium and phosphorus. Serum values of thyroxine and triiodothyronine were lowest (P = 0.002 and P = 0.03, respectively) during the summer months while cortisol showed no seasonal variation. Serum testosterone concentrations were higher in fall and early winter (P less than 0.001) than at other times of the year but were not correlated with semen quality. These results demonstrate that season has no effect on the semen production and quality of captive male Siberian tigers.

Animals↗

PubMed1987

Influence of dietary protein on reproductive performance of dairy cows.

From 10 +/- 3.5 d after parturition to 149 +/- 3.5 d of lactation, 146 cows (109 Holstein and 37 Ayrshires) were fed either a 15 or 20% crude protein diet of 45% sorghum silage and 55% concentrate. Milk production was enhanced by the 20% protein diet, but percentage of milk fat and protein were unchanged. Average daily intake of DM was unaffected by diet. Actual decreases in body weight and condition were small, although cows on 15% protein lost more condition. Concentration of plasma urea nitrogen increased rapidly during the first 4 wk of the experiment with cows on the 20% protein diet maintaining a 10 mg/dl advantage after the 4th wk on experiment. Diet did not affect the postpartum interval to first normal corpus luteum and standing estrus. Cows were inseminated artificially between 55 and 145 d post-calving with one freeze batch of semen from one bull of each appropriate breed mainly by one inseminator. Overall, days open, services per conception, and percentage cows pregnant on experiment were 80, 1.40, and 85, respectively. Concentration of protein in the diet did not affect these reproductive traits. There was no conflict between the amount of dietary protein provided for lactation and reproduction in this experiment.

Animals↗

PubMed1990

Laparoscopic artificial insemination in sheep.

The goal of any AI program is to create improved offspring, and the achievement of this objective will depend on the breeding value of the ram and ewe selected. Laparoscopic AI is being utilized in the sheep industry to extend the use of superior rams, and it offers the producer the opportunity to maximize the reproductive potential of superior sheep. Rapid genetic trait infusion of known superior stud rams into the flock is the primary economic benefit of laparoscopic AI. The success of laparoscopic AI depends on events and factors that interrelate in a complex way. Once the selection and preparation of the ewe have been accomplished, one of the more important steps in the program is the successful synchronization of the ewe to deliver the necessary ova to the site of fertilization at a specific time. One of the best methods of synchronization for laparoscopic AI is the use of a progesterone product for a controlled time period and the administration of PMSG upon its removal. Detecting the onset of estrus is critical, and the addition of sterile (e.g., vasectomized) males is helpful, even essential, to accurately determine when each ewe begins her estrus. The ram effect has been shown to stimulate ovulation and estrus. Ewes must be inseminated within a narrow window of time after the synchronization product is removed. Ewes should be inseminated in the order in which they begin to exhibit signs of behavioral estrus, but age, stage of lactation, duration of behavioral estrus, and breed must be taken into account when this order is established. Fresh-extended semen works well throughout this preferred time frame established for laparoscopic AI, but frozen semen gives best results when used near the end. Advancement in manufacturing technology today removes equipment as a variable factor. It is important, therefore, that the inseminator develop a level of expertise in laparoscopy to ensure maximum fertilization rates. If available, fresh-extended semen is preferred over frozen semen, using at least the minimal number of spermatozoa necessary for fertilization. Evaluation of the post-thaw frozen or fresh semen is necessary to determine motility, morphology, and concentration, all of which help determine the volume of the insemination dose. The minimum necessary for laparoscopic AI in fine-wooled breeds is 20 X 10(6) normal motile spermatozoa; however, the more seasonal and less fertile American sheep need approximately 40 to 50 X 10(6) normal motile sperm to achieve acceptable fertility rates.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMedDate not supplied

Teratospermic and normospermic domestic cats: ejaculate traits, pituitary-gonadal hormones, and improvement of spermatozoal motility and morphology after swim-up processing.

Electroejaculate traits, testicular volume, and circulating FSH, LH, and testosterone concentrations were compared between two populations of domestic cats consistently producing either a high (greater than 60%, normospermic) or low (less than 40%, teratospermic) incidence of structurally normal spermatozoa/ejaculate. The effects of semen dilution in Biggers, Whitten and Whittingham (BWW) or modified Krebs Ringer bicarbonate (mKRB) medium and swim-up processing on sperm viability and duration of motility in vitro also were assessed. Ejaculate volume, percent sperm motility, sperm progressive motility, motile spermatozoa/ejaculate, testes volume, and mean serum FSH and LH concentrations were similar (P greater than 0.05) between normospermic and teratospermic cats. However, sperm concentration/ml of ejaculate was greater and circulating testosterone levels were lower in teratospermic males. Swim-up processing increased (P less than 0.05) percent sperm motility, progressive motility, and the number of structurally normal sperm cells recovered and also prolonged the duration of sperm motility in both cat populations. In teratospermic ejaculates, swim-up separation increased the proportion of morphologically normal spermatozoa recovered by more than two-fold. Diluting cat semen with either BWW or mKRB increased flagellar bending in both normospermic and teratospermic cats. The sperm motility characteristics of only the teratospermic ejaculates were influenced by medium type; mKRB increased percent sperm motility and progressive motility whereas BWW had no effect. Compared with undiluted raw ejaculates, the duration of sperm motility was improved 18- to 24-fold by diluting semen in either BWW or mKRB medium followed by swim-up processing. This study demonstrates that the electroejaculate characteristics of domestic cats vary markedly and that some males consistently produce high proportions of morphologically abnormal spermatozoa. Diminished serum testosterone concentrations and normal pituitary secretion of FSH and LH in teratospermic males suggest that there is an inverse relationship between gonadal androgen production and pleiomorphic spermatozoa in the domestic cat. The swim-up procedure is effective for recovering motile, structurally normal spermatozoa from teratospermic cats.

Animals↗