Effect of vitamin supplements on some aspects of performance, vitamin status, and semen quality in boars

The aim of the present study was to determine the effects of dietary supplements of vitamins on vitamin status, libido, and semen characteristics in young boars under normal and intensive semen collection. Sixty Landrace, Yorkshire, and Duroc boars were allocated randomly from 6 to 10 mo of age to one of the following diets: 1) basal diet (industry level) for minerals and vitamins (Control, n = 15); 2) basal diet supplemented with vitamin C (ASC, n = 15); 3) basal diet supplemented with fat-soluble vitamins (FSV, n = 15); and 4) basal diet supplemented with water-soluble vitamins (WSV, n = 15). After puberty (approximately 12 mo of age), semen was collected at a regular frequency (three times every 2 wk) for 5 wk. Thereafter, all boars were intensively collected (daily during 2 wk). A recovery period (semen collection three times every 2 wk) followed and lasted for 10 wk. Sperm quality (percentage of motile cells and percentage of morphologically normal cells) and quantity (sperm concentration, semen volume, and total sperm number) were recorded as well as direct and hormone related measurements of boar libido. Blood and seminal plasma samples were taken to monitor vitamin status. High concentrations of B6 (P < 0.05) and folic acid (P < 0.05) were observed in the blood plasma of WSV boars, whereas greater concentrations of vitamin E (P < 0.01) were obtained in FSV boars. In the seminal plasma, folic acid concentrations tended to be greater in WSV boars (P < 0.08). During the intensive collection period, there was a tendency (P < 0.06) for semen production to be greater in WSV boars, the effect being less pronounced (P < 0.10) in FSV boars. During the recovery period, the percentage of motile sperm cells was greater in WSV boars (P < 0.03) and, to a lesser extent, in FSV boars (P < 0.10) compared with Control boars. Sperm morphology and libido were not affected by treatments. These results indicate that the transfer of vitamins from blood to seminal plasma is limited and the dietary supplements of water-soluble and fat-soluble vitamins may increase semen production during intensive semen collection.     

不同品种、月份、月龄及采精间隔对猪精液品质的影响

为研究不同品种、采精月份、采精月龄和采精间隔等因素对加系公猪精液品质的影响,以及品种、初次采精周龄对精液质量稳定性的影响,本研究以江西某种公猪站79头加系大白猪、长白猪、杜洛克猪种公猪为试验群体,收集2018年12月至2020年12月3 921条精液采集与精液质量数据,通过混合线性模型与方差分析探究各因素对精液量、精液密度、精子活力、总精子数及其稳定性的影响。结果显示,从不同品种对精液质量的影响来看,长白猪精液量和总精子数均高于大白猪、杜洛克猪,但杜洛克猪精液密度高于长白猪、大白猪,杜洛克猪精子活力最低;从不同月份来看,1~3月采精精液密度最高,4~6月采精精子活力最高,10~12月采精精液量和总精子数最高,精液量呈现秋冬多、春夏少的季节变化规律。公猪不同月龄采精,精液质量指标也存在差异,月龄越小精液量越低,但精液密度偏高,精子活力相对较好,在19~24月龄黄金期总精子数最高。不同采精间隔对精液质量有较大影响,采精间隔越长,精液量、精液密度、精子活力和总精子数相对较好,采精间隔为5 d时综合性能最佳,但过长的采精间隔导致精子活力降低。品种影响总精子数稳定性,长白猪、大白猪总精子数稳定性显著优于杜洛克猪（P<0.05）。本研究结果表明,品种、采精月份、采精月龄和采精间隔均会影响公猪精液质量,关注这些因素有助于公猪站制定更完善的生产计划,提高公猪利用率。     

不同月龄巴杜公猪精液品质分析

为研究不同月龄巴杜种公猪的精液品质差异,本实验选择8～12、13～18、19～24、25～30、31～36月龄各6头巴杜种公猪,进行精液品质检查。结果表明:随着月龄增加,巴杜种公猪精液的各项指标呈现规律性变化,19～24月龄的采精量、精子密度和精子活率显著高于其他月龄段,且精子畸形率显著低于其他月龄段;24月龄之后采精量、精子密度和精子活率缓慢下降,而畸形率则逐渐上升。本研究结果可为合理选择配种日龄、人工授精公猪的使用年限及人工授精的输精量提供数据支撑,为巴杜种公猪精液的合理应用及提高猪场经济效益提供参考依据。     

品种、季节、胎次、采精月龄及采精间隔对猪精液品质的影响

【目的】探究品种、公猪出生胎次、公猪同窝仔猪数、公猪乳头数、采精季节、采精月龄和采精间隔对猪精液品质的影响,以及不同品种对精液质量稳定性的影响。【方法】选取909头杜洛克、长白、大白种公猪为试验群体,收集2021年4月至2022年4月27 408条精液测定记录,采用混合线性分析模型和方差分析探究品种、公猪出生胎次、公猪同窝仔猪数、公猪乳头数、采精季节、采精月龄和采精间隔对精液体积、精液密度、精子活力、直线前进运动精子比例、精子畸形率、总精子数及各精液性状稳定性的影响。【结果】从不同品种对精液品质的影响来看,长白猪精液体积和总精子数均显著高于大白猪、杜洛克猪(P<0.05),杜洛克猪精液密度显著高于大白猪和长白猪(P<0.05),杜洛克猪、大白猪精子活力均显著高于长白猪(P<0.05),大白猪直线前进运动精子比例显著高于长白猪和杜洛克猪(P<0.05),长白猪和大白猪精子畸形率均显著低于杜洛克猪(P<0.05);从不同公猪出生胎次对精液品质的影响来看,1～3胎出生的公猪具有较高的精液品质;从不同采精季节对精液品质的影响来看,精液密度、精子活力和总精子数秋、冬...     

Multivariate Analyses for Determining the Association of Field Porcine Fertility With Sperm Motion Traits Analysed by Computer‐Assisted Semen Analysis and With Sperm Morphology

This study investigates the association of semen traits with boar fertility. The fertility outcome (farrowing rate – FR and total piglets born – TB) of 14 boars was obtained from a field trial conducted during 10 week of breeding period on a commercial farm using multiparous sows (n = 948) through single‐sire mating with 2 × 10⁹ motile sperm cells per artificial insemination (AI) dose. Sperm motion parameters, evaluated with computer‐assisted semen analysis system in raw and stored semen at 17°C for 240 h, in addition to morphological sperm defects, measured on the collection day, were included in the analysis to determine which semen traits were important to discriminate the fertility potential of ejaculates from these boars. The data underwent multivariate cluster, canonical and discriminant analyses. Four clusters of boars were formed based on fertility outcome. One boar, with the lowest FR and TB values (89.7% and 11.98), and two boars, with the highest FR and TB values (97.8% and 14.16), were placed in different clusters. The other boars were separated in two distinct clusters (four and seven boars), including boars with intermediate TB (12.64 and 13.22) but divergent values for FR (95.9% vs 91.8%). Semen traits with higher discriminatory power included total motility, progressive motility, amplitude of lateral head displacement and cytoplasmatic droplets. Through multivariate discriminant analysis, more than 80% of the 140 ejaculates were correctly classified into their own group, showing that this analysis may be an efficient statistical tool to improve the discrimination of potential fertility of boars. Nevertheless, the validation of the relationship between fertility and semen traits using this statistical approach needs to be performed on a larger number of farms and with a greater number of boars.     

Factors influencing boar sperm cryosurvival

Optimal sperm cryopreservation is a prerequisite for the sustainable commercial application of frozen-thawed boar semen for AI. Three experiments were performed to identify factors influencing variability of postthaw sperm survival among 464 boar ejaculates. Sperm-rich ejaculate fractions were cryopre-served using a standard freezing-thawing procedure for 0.5-mL plastic straws and computer-controlled freezing equipment. Postthaw sperm motility (assessed with a computer-assisted semen analysis system) and viability (simultaneously probed by flow cytometry analysis after triple-fluorescent stain), evaluated 30 and 150 min postthaw, were used to estimate the success of cryopreservation. In the first experiment, 168 unselected ejaculates (1 ejaculate/boar), from boars of 6 breeds with a wide age range (8 to 48 mo), were cryopreserved over a 12-mo period to evaluate the predictive value of boar (breed and age), semen collection, transport variables (season of ejaculate collection, interval between collections, and ejaculate temperature exposure), initial semen traits, and sperm quality before freezing on sperm survival after freezing-thawing. In Exp. 2, 4 ejaculates from each of 29 boars, preselected according to their initial semen traits and sperm quality before freezing, were collected and frozen over a 6-mo period to evaluate the influence of interboar and intraboar ejaculate variability in the survival of sperm after cryopreservation. In Exp. 3, 12 ejaculates preselected as for Exp. 2, from each of 15 boars with known good sperm cryosurvival, were collected and frozen over a 12-mo period to estimate the sustainability of sperm cryosurvival between ejaculates over time. Boar and semen collection and transport variables were not predictive of sperm cryosurvival among ejaculates. Initial semen traits and sperm quality variables observed before freezing explained 23.2 and 10.9%, respectively, of the variation in postthaw sperm motility and viability. However, more that 70% of total variance observed in postthaw sperm quality variables among ejaculates was explained by boar. This indicates that boar is the most important (P < 0.001) factor explaining the variability among ejaculates in sperm cryosurvival, with most (14 of the 15 boars in Exp. 3) showing consistent (P > 0.05) sperm cryosurvival over time.     

Effects of dietary supplementation with an organic source of selenium on characteristics of semen quality and in vitro fertility in boars

Semen characteristics in boars fed organic or inorganic sources of Se were assessed in 3 experiments. Crossbred boars were randomly assigned at weaning to 1 of 3 dietary treatments: I) basal diets with no supplemental Se (control), II) basal diets with 0.3 mg/kg of supplemental Se from an organic source (Sel-Plex, Alltech Inc., Nicholasville, KY), and III) basal diets supplemented with 0.3 mg/kg of supplemental Se from sodium selenite (Premium Selenium 270, North American Nutrition Co. Inc., Lewisburg, OH). For Exp. 1, semen was collected from boars (n = 10/dietary treatment) on 5 consecutive days at 15 mo of age. Effects of treatment × day were detected for the proportions of progressively motile (P = 0.02) and rapidly moving (P = 0.03) spermatozoa, and measures of sperm velocity, including path velocity of the smoothed cell path (P = 0.05) and average velocity measured in a straight line from the beginning to the end of the track (P = 0.05). Negative effects of day of semen collection on sperm motility were least pronounced in boars fed Sel-Plex. Experiment 2 was conducted when boars were 17 mo of age, and semen was collected (n = 10 boars/dietary treatment), diluted in commercially available extenders, and stored at 18°C for 9 d. Effects of treatment × day were detected for percentages of motile (P = 0.01) and static (P = 0.01) spermatozoa, amplitude of lateral head displacement (P = 0.02), frequency with which the sperm track crossed the sperm path (P = 0.04), straightness (P = 0.01), and average size of all sperm heads (P = 0.03). In general, sperm cells from boars fed Sel-Plex were better able to maintain motility during liquid storage compared with boars fed sodium selenite. For Exp. 3, semen was collected from boars (n = 6/dietary treatment) at 23 mo of age, and spermatozoa were evaluated at d 1 and 8 after semen collection using in vitro fertilization procedures. There was a tendency for an effect (P = 0.11) of dietary treatment on fertilization rate with Sel-Plex-fed boars having the greatest value (70.7%). The results of this study suggest that there are positive effects of dietary supplementation with Sel-Plex on boar semen characteristics and that organic Se supplementation may help ameliorate the negative effects of semen storage on characteristics of sperm motility.     

中草药复方制剂对公猪精液品质和生殖激素的影响

为了研究中草药复方制剂对公猪精液品质和生殖激素的影响,对27头精液品质相近的成年大约克种公猪饲喂不同剂量的中草药复方制剂,测定精液指标和血清生殖激素水平。结果表明:与对照组相比,2%低剂量组(试验Ⅰ组)的采精量、采精持续时间、精子密度,血清中促卵泡刺激素(FSH)、促黄体生成素(LH)和睾酮(T)含量差异显著(P<0.05);与对照组相比,3%高剂量组(试验Ⅱ组)的采精持续时间、精子活力和血液中LH、T含量显著提高,采精量和血液中FSH含量差异极显著(P<0.01);高、低剂量组的精子畸形率与对照组相比均有所降低。说明日粮中添加一定剂量中草药复方制剂可显著提高种公猪的精液品质,促进生殖激素的分泌。     

Artificial insemination in swine.

This article analyses the advantages and disadvantages of artificial insemination with semen purchased from a center as well as from the herd boars on the farm. Intensive swine production could benefit greatly by adapting artificial insemination with herd boars, particularly from savings in labor and boar numbers. The techniques for semen collection, extension, and insemination are described, and sources for equipment given. Expected results of artificial insemination are quoted from experiments and international field experience.     

Fertility Results of Artificial Inseminations Performed with Liquid Boar Semen Stored in X-CellTM vs BTS Extender

The objective of the present field study was to compare the fertility results for boar semen diluted in X-cell stored up to 4-5 days before artificial insemination (AI) with semen diluted in Beltsville thawing solution (BTS) used for AI following 2-3 days of storage (where the first day being the collection day). A total number of 2601 double inseminations in Norwegian herds were included in this two-trial study. All the boars used in the study were mature cross-bred Norwegian Landrace x Duroc (LD), which were routinely used for AI in Norway. The inseminated gilts and sows were Norwegian Landrace x Yorkshire (LY). The AI doses contained 2.5 billion spermatozoa, and consisted of a mixture of semen from three, occasionally four, boars (i.e. heterospermic semen). Fertility was measured in terms of the likelihood of farrowing and subsequent litter size. The fertility of the semen in both of the extenders was satisfactory and no significant differences were found either in semen stored 4-5 days in X-cell compared with 2-3 days in BTS or in semen stored 2-3 days in X-cell compared with 2-3 days in BTS. The storage capability findings for the long-term extender X-cell could significantly simplify the practical issues of semen production and the distribution of AI doses containing 2.5 billion spermatozoa. However, in pig production systems where all semen is used within 2-3 days, the short-term extender BTS is as good as the more expensive extender X-cell.     

Electroejaculation and artificial insemination in Vietnamese potbellied miniature pigs

A 15-month-old Vietnamese miniature boar was examined because of suspected infertility. A breeding soundness examination was conducted, using electroejaculation under anesthesia for semen collection. Semen values were normal despite a subpubic location of the testes. Artificial insemination of a gilt with extended semen resulted in the birth of a litter 111 days later. Vietnamese potbellied boars have small and sometimes nearly undetectable scrotal pouches, which may cause the producer to question the fertility of the boars.     

Estimation of Genetic Parameters and Analysis of Season Effects and Age Effects for Semen Traits in Landrace Boars

The purpose of this study was to estimate the genetic parameters of semen traits of Landrace boars in South China and to analyze the influence of the age and season of semen collection on semen traits, so as to provide theoretical basis for formulating reasonable boar breeding program. The Asreml-R was used to analyze the 107 221 semen data of 1 605 Landrace boars from 2 AI stations in Southern China, the single-trait repeatability animal model was used to estimate the variance components, heritability and repeatability of each semen traits, two-trait repeatability animal model was used to estimate genetic correlation and phenotypic correlation of semen volume, semen density, sperm motility and percentage of abnormal sperm. The general linear model of R language program was used to analyze the influence of age and season of semen collection on semen traits. The results showed that the semen volume and percentage of abnormal sperm had medium heritability (0.23 and 0.38), and the variation coefficient of percentage of abnormal sperm was 85.42%, while the other traits had low heritability (0.07-0.19). Semen volume-semen density and sperm motility-percentage of abnormal sperm had extremely significantly negative genetic correlation(-0.77 and -0.90, respectively). Semen density-sperm motility showed extremely significantly positive genetic correlation (0.50). The influence of the age of semen collection on semen traits was significant(P<0.05). After boars reached sexual maturity, semen volume showed a significant increase, semen density and percentage of abnormal sperm showed a general decrease, and total sperm number and functional sperm number were significantly higher in the 13-18-month of age group than those in the other groups (P<0.05). The semen density was the highest in spring, and the total sperm number and functional sperm number were significantly higher in autumn and winter than those in spring and summer (P<0.05). In conclusion, the semen volume and percentage of abnormal sperm of Landrace boars can be selected as candidate traits. In the boar production management, boar whose semen production after 36 months of age decline, will be considered to update. Boar semen quality was significantly higher in autumn and winter than those in spring and summer. It is suggested that cooling work should be done in advance in Southern China in summer.     

OC1Effects of Cryopreservation on the Expression of Glut‐3, Glut‐5 and As‐A Proteins in Iberian Boar Sperm Membranes

In order to determine the injure produced in boar spermatozoa through cryopreservation process, we analyzed the expression of the hexose transporters Glut‐3 and Glut‐5 and the zona pellucida binding protein As‐A (P68) in three different steps of the freezing‐thawed protocol: at 17°C (fresh BTS‐diluted semen, 1 : 2 v/v, step 1), at 5°C (after glycerol addition; step 2), and post‐thawing (step 3). All sperm analyses were carried out with immunogold techniques under electronic microscopy. For this study eight healthy post‐pubertal Iberian boars were submitted to a collection of twice per week through 3 months, evaluating two ejaculates from each boar. Glut‐3 maintains the expression in the acrosome region post‐thawing but not along the tail where is reduced. The expression of Glut‐5 and As‐A is majority located at the post‐acrosome region of the spermatozoa at step 1, but in step 2 and step 3 this expression is relocated to sperm tail area. In conclusion, while cryopreservation affects the localization and the expression of Glut‐3 and Glut‐5, its fertilizing capacity is not significantly reduced. The stabilization of boar semen at 5°C was found to be the most crucial step for sperm survival.     

长白公猪精液性状遗传参数评估及采精月龄和季节因素分析

旨在估计华南地区长白种公猪精液性状遗传参数以及分析公猪采精月龄和季节对精液性状的影响,为合理制定种公猪育种方案提供理论依据。本研究采用Asreml-R对华南地区两个公猪站1 605头长白公猪107 221条精液数据进行统计分析,利用单性状重复力动物模型估计公猪精液各性状的方差组分、遗传力和重复力,利用两性状重复力动物模型对精液体积、精液密度、精子活力和精子畸形率等性状进行遗传相关和表型相关估计;利用R语言程序中的一般线性模型分析采精月龄和季节对精液性状的影响。结果表明,精液体积和精子畸形率属于中等遗传力（0.23和0.38）,其中精子畸形率的变异系数较大,为85.42%,其余性状都为低遗传力（0.07~0.19）;精液体积与精液密度以及精子活力与精子畸形率为极显著遗传负相关（-0.77和-0.90）;精液密度与精子活力呈极显著的遗传正相关（0.50）。采精月龄对精液性状影响显著（P<0.05）,在公猪达到性成熟后,精液体积呈显著上升趋势,精液密度和精子畸形率总体呈下降趋势,精子总数和有效精子数在13~18月龄组显著高于其他组（P<0.05）。在春季精液密度最高,精子总数和有效精子数在秋、冬季显著优于春、夏季（P<0.05）。综上,长白公猪精液体积和精子畸形率具有较大的选育潜力,可作为候选性状进行选择。在公猪生产管理方面,公猪36月龄后精液产量下降,考虑更新淘汰。公猪精液品质在秋、冬季显著优于春、夏季,在中国南方夏季应提前做好降温工作。     

Effect of experimental classical swine fever (CSF) infection on libido and ejaculate parameters in boars

The objective of this study was to characterize the effect of an experimental infection with the classical swine fever (CSF) virus on libido and ejaculate parameters of adult boars. Four boars 10 month old were infected with a CSF field isolate (Visbek/Han95). Semen was collected every second day after infection and daily during the pyrexic phase. The only clinical signs in the boars were an increase in body temperature, but never above 39.9 degrees C and a temporally reduction of food intake. The libido was always good, so semen collection was performed in three boars without difficulty and the semen quality was always in the range of the minimum requirements for sperm that is used for artificial insemination. Although one boar had a good libido only a sperm free ejaculate could be collected on one day. The results show that a CSF virus infection of adult boars hardly causes any clinical symptoms and that sperm can be obtained despite fever. Insemination boars may thus be of special epidemiological relevance for the dissemination of the CSF virus.     

Measurement of semen production rates of boars

Frequency of semen collection was used to determine methods of stabilising epididymal sperm reserves in young boars in order to measure daily sperm output which then allows estimation of daily sperm production. By collecting from boars 3 times a week (Monday, Wednesday and Friday) most boars reached epididymal stabilisation within 4 weeks and the daily sperm output could be calculated from the following 6 collections. A more rapid method of measuring daily sperm output was achieved by collecting from boars 4 or 5 times during one day and daily for the following 4 days. Daily sperm output measured by this method was not found to be significantly different from the method requiring collections over a 6-week period. Frequency of collection had a significant effect on semen characteristics. Collecting 3 times a week resulted in significantly greater volumes, sperm concentration, total number of sperm in the ejaculate and daily sperm output compared with collecting at intervals of 48 h. A collecting frequency of 48 h resulted in significantly greater volumes, sperm concentration and total number of sperm in the ejaculate but not daily sperm output when compared with collecting every 24 h.     

B‐mode Ultrasound and Grey‐Scale Analysis of the Epididymis in Boars,and the Relationship to Semen Parameters

This study investigated the epididymis of mature boars (n = 10) by means of B‐mode ultrasound and grey‐scale analysis (GSA) for echogenicity (EG) determination using an ultrasound unit HS 1500V, a linear transducer (frequencies 7.5–9.0 MHz), and standardized unit settings. All boars had their epididymal caput, corpus and cauda scanned six times before and after semen collection, respectively, at weekly intervals. Semen was subjected to spermatological examination including volume, total and forward motility, sperm abnormalities, as well as total sperm count and concentration. The caput and corpus both had a homogeneous fine echotexture. The cauda was homogeneous too but had a marbled echotex‐ture. Echogenicity before and after semen collection was caput > corpus > cauda, respectively (p < 0.001). Echogenicity was higher before than after semen collection for all parts of the epididymis, respectively (p < 0.001). Echogenicity of the caput correlated slightly positively with the total sperm count pre‐collection (r = 0.301; p = 0.020) and with ejaculate volume pre‐ and post‐collection (r = 0.302 vs 0.306; p = 0.017 vs 0.019), and slightly negatively with sperm concentration post‐collection (r = ?0.275; p = 0.034). No relationship was found for EG of the corpus and cauda for any of the ejaculate parameters. In conclusion, B‐mode ultrasound and GSA proved feasible for imaging the epididymis in boars. Single relationships between EG and ejaculate parameters were found and deserve further investigation.     

Testicular changes observed in boars following experimental inoculation with pseudorabies (Aujeszky''s) virus.

Four boars were inoculated intranasally with pseudorabies virus to determine if microscopic testicular changes occurred as a result of infection. Testicular biopsies and semen samples were taken at two, four and six weeks postinoculation and the boars were castrated immediately after the last sample collection. Testicular samples and semen were cultured to determine if the virus was present. Pseudorabies virus was not isolated from the semen or testicular tissue. Virus was isolated from trigeminal ganglia at necropsy and from nasal swabs taken one day after castration. Consequently, a time of high risk for shed of the virus from clinically normal carrier animals is immediately following castration. Gross changes were not observed in testicular tissues and microscopic changes in the testicles were the result of biopsy. Lesions consistent with pseudorabies virus infection were observed in the central nervous system of all inoculated boars. Temporary lowered fertility may result from the effects of elevated body temperature on spermatogenesis during acute clinical disease. However, it appears that the strain of pseudorabies virus used, lacked the ability to infect and/or replicate in the boars' reproductive tracts.     

Ein Beitrag zur Beurteilung der täglichen Spermienproduktion bei Ebern der Deutschen Landrasse

Inhalt Bei 8 Ebern der Deutschen Landrasse im Alter von 1 bis 4 Jahren wurde die spermatogenetische Leistung durch Entsamungen mit unterschiedlichen Intervallen untersucht. Dabei wurde festgestellt, daβ die tägliche Spermienproduktion des 1jährigen Ebers bei 10 · 10⁹ Spermien liegt und beim 4jährigen Eber 20 · 10⁹übersteigt. Die Spermienproduktion von Ebern ist, wie bei anderen Tierarten, von Alter und damit vom steigenden Hodengewicht der Tiere abhängig. Mit einer Vergröβerung der Entsamungspausen steigen die Spermienverluste an und der errechnete tägliche Spermien-“output” nimmt ab. Contents (A contribution to the evaluation of the daily sperm production of boars of German Landrace breed). The “Daily Sperm Output” in boars was examined by means of various semen collection intervals. Eight boars–German landrace type, age one to four years-served as test animals. The investigations established a daily sperm production of 10·10⁹ sperms with one year old boars whereas 4 years old boars produce more than 20 · 10⁹ sperms. The sperm production depends on age and growing testis weight as is observed in other animal species With increased pauses of semen collection sperm losses are likewise increased, and the calculated “Daily Sperm Output” is diminished.     

Bilateral removal of the cauda epididymides in the neonatal pig as a technique for creating teaser boars

Five pairs of crossbred littermate boars were used to assess the efficacy of bilateral removal of the cauda epididymides at an early age as a technique for creating teaser boars. The cauda epididymides were surgically removed in one of each litter pair; the other of the pair served as an intact control. Boars subjected to removal of the epididymides (Epid) were rendered sterile by the technique. The Epid-treated and control untreated littermate boars had similar levels of sexual aggression and libido, as measured by behavioral characteristics at semen collection. The Epid-treated boars showed a slight, but not significant, reduction in ejaculate volume. Upon slaughter at 273 d of age, Epid and control boars had similar weights for the accessory sexual organs and penis and similar penile lengths. The Epid-treated boars displayed enlarged caput epididymides and granulomata. It is suggested that bilateral removal of the cauda epididymides in the neonatal pig may prove a worthwhile alternative to the traditional vasectomy procedure to create teaser boars.