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1.
In situ length and width of both testes and body weight were recorded on 40 Chester White, 60 Landrace, 60 Large White and 62 Yorkshire boars born in the spring and on 57 Duroc, 54 Hampshire, 57 Pietrain and 50 Spot boars born in the fall. Testicular biopsies on one-half of the boars in each breed group were evaluated for percentage of tubules with complete spermatogenesis and for diameter of tubules. Testicular volume of both testes was estimated at 98 and 154 d of age and 36 and 81 kg. Breed effects were significant for all testicular traits except testicular volume at 36 kg in the spring farrowing and testicular volume at 98 d of age in the fall farrowing. The estimate of heritability for testicular volume was low at 98 d of age (.12 +/- .14) but large at 154 d of age (.55 +/- .12). Heritability estimates for testicular volume were lower at constant weights (.11 +/- .14 and .14 +/- .12) than at constant ages (.12 and .55). Heritability estimates for traits measured by biopsy were moderate to large (.22 +/- .22 to .78 +/- .18). Phenotypic correlations of in situ testicular volume with traits measured by biopsy were moderate and positive when estimated within a breed (.16 to .52). Genetic correlations of testicular volume at constant ages and weights with traits measured by biopsy were moderate to large and positive (.58 to greater than 1.0); similar correlations among bred means were quite variable (-.35 to .91). Selection for increased testicular volume would not be antagonistic to selection goals for growth and backfat. However, selection for improvement in traits measured by biopsy may result in undesirable changes in growth rate and backfat probe. Genetic correlations of testicular traits with age at puberty and litter size of females were not consistent in magnitude or sign between the two estimation procedures.  相似文献   

2.
Chinese Erhualian pigs are known for prolificacy with distinct reproductive traits compared with Western commercial breeds. In this study, a four‐generation intercross resource population was constructed using White Duroc boars and Chinese Erhualian sows as founder animals, and a total of 14 male reproductive traits were recorded in 411 F2/F3 boars including the testis and epididymis weights, the seminiferous tubular diameter and spermatogenesis at 60, 90 and 300 days of age, semen characteristics, serum testosterone concentration and libido level at 300 days of age. The White Duroc–Erhualian boars showed remarkable segregations in the traits measured except for the seminiferous tubular diameter and had high ratio (13.9%) of the abnormality of spermatogenesis, providing a good experimental population for detecting quantitative trait loci affecting these male reproductive traits. Furthermore, the correlations among nine male reproductive traits at 300 days of age indicated that the testis weight and the body weight were strongly correlated with the sperm production, supporting the two traits as important parameters for boar selection to increase sperm production and ultimately improve boar fertility. The libido level in the White Duroc–Erhualian boars that was evaluated by a new and easily recorded scoring system showed a significant correlation with serum testosterone concentration. Yet, both libido and serum testosterone concentration were not correlated with the sperm production. Results of this study provided new information on the male reproductive physiology and genetics in Chinese Erhualian and White Duroc boars.  相似文献   

3.
为探讨不同配种方式对二元母猪产仔数的影响,以杜洛克猪、长白猪、大白猪、皮特兰猪四个品种公猪精液采用人工授精的方法对11654头长大二元母猪配种,对所产11654窝总产仔数、窝产活仔数、窝损失等进行统计和分析,分析不同配种模式对二元母猪繁殖性能的影响。结果表明,配种次数、不同品种公猪组合配种对二元母猪总产仔数、产活仔数以及窝损失均无显著影响（P〉0.05）,但杜洛克公猪所配二元母猪的总产仔数和窝产仔数均高于大白和长白猪（P〈0.05）;采用长×杜×大组合配种的二元母猪总产仔数和窝产活仔数均高于其它三种组合。试验结果表明,在生产中,可在长白、大白、杜洛克猪中任选两个品种,通过二次配种的方式提高母猪的产仔数。  相似文献   

4.
An excessive accumulation of androstenone in pig adipose tissue is a major contributor to the phenomenon of boar taint. Androstenone deposition is dependent on the rate of androstenone biosynthesis in testis and androstenone degradation in liver. The aim of the current study was to examine the possibility of the existence of breed-specific mechanisms controlling androstenone accumulation in pig adipose tissue. The specific objective was to investigate the expression of some of the key enzymes involved in testicular and hepatic androstenone metabolism in pigs of 2 breeds by using animals with high and low androstenone concentrations within each breed. The study was conducted with Norwegian Landrace (N. Landrace) and Duroc boars. The mean androstenone values for the low- and high-androstenone groups were 0.1 +/- 0.01 microg/g and 7.58 +/- 0.68 microg/g for N. Landrace boars, and 0.22 +/- 0.04 microg/g and 13.55 +/- 1.14 microg/g for Duroc boars. The enzymes investigated were 3beta-hydroxysteroid dehydrogenase (3beta-HSD), cytochrome P450-c17, and sulfotransferase 2B1 (SULT2B1). Expression of cytochrome P450-c17 in liver and testis did not differ between animals with high and low androstenone concentrations in either the N. Landrace or Duroc breed. Expression of hepatic 3beta-HSD, which catalyzes the first stage of androstenone degradation, was decreased in high-androstenone N. Landrace boars (P < 0.01), but not in high-androstenone Duroc boars. In contrast, the expression of hepatic SULT2B1, which catalyzes the second stage of steroid catabolism, was decreased in high-androstenone Duroc animals (P < 0.05), but not in high-androstenone N. Landrace animals. Sulfotransferase 2B1 was also inhibited in testis of high-androstenone pigs of both breeds compared with low-androstenone animals. We report breed differences in expression of the androstenone-metabolizing enzymes 3beta-HSD and SULT2B1 in the liver of high- and low-androstenone pigs. It is suggested that accumulation of androstenone in adipose tissue of N. Landrace boars might be related to a low rate of hepatic androstenone degradation in metabolic stage I, whereas the high androstenone concentration in Duroc boars might be related to a low rate of androstenone metabolism in metabolic stage II.  相似文献   

5.
Duroc, Meishan, Fengjing, and Minzhu boars were mated to crossbred gilts during two breeding seasons. From each sire breed group each season, six pens of approximately eight barrows each were slaughtered. A pen of pigs from each sire breed group was slaughtered at 7-d intervals from 168 to 203 d of age each season. Breed of sire effects were significant for all age-adjusted carcass traits except carcass length, fat thickness at the last rib, color score, and firmness score. At 184 d of age, Duroc crosses had the heaviest (P less than .05) slaughter and carcass weights; Minzhu crosses were lighter (P less than .05) than Meishan crosses but not lighter than Fengjing crosses. Differences among age-constant traits reflect differences in BW. After adjustment to a constant carcass weight of 78 kg, the three Chinese breeds had very similar carcass characteristics. Carcasses sired by Durocs had significantly less backfat and larger longissimus muscle area than carcasses sired by the Chinese breeds. Weight of each trimmed wholesale lean cut and their total weight were significantly higher for Duroc crosses than for Chinese crosses. Breed of sire means did not differ significantly for belly weight, but Duroc crosses had less (P less than .05) weight of leaf fat. Relative to Chinese crosses, longissimus muscles from Duroc crosses had more marbling (P less than .05). Sire breed groups did not differ significantly for color or firmness score. Pigs sired by Meishan, Fengjing, and Minzhu produced carcasses with significantly less lean content at a carcass weight of 78 kg than did pigs sired by Duroc.  相似文献   

6.
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.  相似文献   

7.
Phospholipase C zeta (PLCz) and cyclooxygenase isoenzyme type 2 (COX-2) are important in spermatogenesis, but their effect has not yet confirmed in pigs. Therefore, this study was aimed to analyse their association with sperm quality and fertility and to identify the mRNA and protein expression in boars reproductive tissues. DNA samples from 231 Pietrain (PI) and 109 Pietrain × Hampshire (PIHA) pigs with records of sperm quality [sperm concentration (SCON), motility, semen volume, plasma droplet and abnormal spermatozoa rate] and fertility (non-return rate and number of piglet born alive) traits were available. A SNP in non-coding region of PLCz g.158 A > C was associated with SCON (p < 0.05) in PIHA population while the polymorphism of COX-2 g.68 G > A in 3' UTR was not associated with any traits. For mRNA and protein expression study, a total of six boars were divided into two groups with G-I and G-II, where G-I was characterized for relatively better sperm quality. Both genes expressed higher in reproductive tissues compared with non-reproductive tissues. Phospholipase C zeta mRNA expressed higher in testis (p < 0.01), all parts of epididymis and spermatozoa from G-I, while COX-2 expressed higher in testis (p < 0.05), head and body of epididymis (p < 0.01), and spermatozoa from G-II boar. Both proteins were localized in Leydig cells and spermatozoa. These results might shed light on roles of these genes in spermatogenesis as candidate for boar sperm quality and fertility, but still the lack of association across populations should be considered.  相似文献   

8.
This study was undertaken to evaluate the effect of body condition score (BCS) on testicle and epididymis biometrics, semen characteristics and testosterone level in Egyptian Jack. This study was conducted on 50 mature Jacks divided according to their body condition score into four groups: Poor (G1), moderate (G2), good (G3) and fat (G4). The complete testis was collected immediately after execution in the Giza Zoo abattoir; then, the epididymis was carefully dissected at the testicular junction. Biometrical measures including length, weight and volume were determined for the right and left testis and epididymis. Also, epididymal sperm was collected from all examined animas and evaluated for sperm concentration, progressive motility, viability and sperm abnormalities. Serum samples were collected for determination of total testosterone level. Results showed that the body condition score of the examined animal affects their biometrical measure of testicles and epididymis. There is a significant decrease (p < .05) in biometrical measures for the testicles and epididymis, sperm concentration, motility, viability and testosterone level in poor BCS animals (G1). The highest values were recorded in Good BCS (G3) Jacks. Conclusion: Jacks with good BCS (G3) should be selected for breeding activity in donkey.  相似文献   

9.
Crossbred progeny sired by either Duroc or Pietrain boars, normal for the ryanodine receptor gene, were evaluated for carcass composition and meat quality. Boars from each breed were mated to Yorkshire or F1 Yorkshire-Landrace females. A total of 162 off-spring was evaluated for carcass and meat quality traits at a common age (approximately 26 wk of age). Duroc-sired progeny had heavier (108.0 vs. 103.0 kg, P < 0.001) and longer carcasses (86.9 vs. 84.8 cm, P < 0.01), whereas Pietrain-sired pigs had less backfat at the first rib (44.6 vs. 47.7 mm, P < 0.01), last lumbar vertebrae (20.9 vs. 23.0 mm, P < 0.05), and 10th rib (23.0 vs. 25.5 mm, P < 0.01). No difference between Pietrain and Duroc progeny was detected for fat depth at the last rib (27.8 vs. 28.8 mm, respectively). Pietrain progeny had a higher percentage of lean at slaughter (52.6 vs. 50.7, P < 0.05) and higher dressing percentage (74.0 vs. 73.1, P < 0.01). Primal cut weights were collected with Pietrain progeny having a greater percentage of carcass as ham (23.0 vs. 22.4, P < 0.01) and loin (21.6 vs. 21.2, P < 0.05), whereas Duroc progeny had a higher percentage of belly weight (12.0 vs. 11.7, P < 0.05). Percentages of Boston butt (8.8 vs. 9.0) and picnic shoulder (9.9 vs. 9.9) were similar for Duroc vs. Pietrain progeny. Total weight of these five primal cuts, as a percentage of carcass weight, was higher for Pietrain progeny (75.2 vs. 74.3, P < 0.01). With heavier carcass weight, Duroc progeny had greater primal cut weights as a function of age. Subjective meat quality scores for color, marbling, and firmness (1 to 5 scale) were more favorable for Duroc-sired progeny. Furthermore, chops from Duroc progeny had higher 24-h pH (5.53 vs. 5.48, P < 0.001) and Minolta a* (17.33 vs. 17.04, P < 0.05) with less percentage drip loss (2.88 vs. 3.80, P < 0.001). No differences were detected between Duroc- and Pietrain-sired progeny for Minolta L* (54.77 vs. 55.37) or b* (7.58 vs. 7.58) objective color scores, percentage cooking loss (28.63 vs. 29.23), or Warner-Bratzler shear force (6.94 vs. 7.11 kg). Both sire breeds have beneficial traits that can be utilized in commercial pork production and merit further study.  相似文献   

10.
The objective of this study was to assess parameters of sexual behavior, seminal characteristics, testicular measurements, and their correlations in Piau boars. A total of 169 observations of the sexual behavior and prelude duration (courting) of 10 Piau boars aged from 0.8 to 6.4 years were made; semen was also collected from these animals. The testicular length (TL), testicular width (TW), testicular shape (TS; 1-5), and testicular volume (TV) of these animals were measured. The seminal physical and morphological characteristics of 60 ejaculates from 6 boars were assessed for volume of ejaculate (VOL), volume of the gelatinous portion (VOLGEL), aspect (ASP), sperm motility (MOT), spermatic vigor (VIG), spermatic concentration per milliliter (CONCML), total concentration (CONCT), and morphological characteristics (major defects [MAJDEF]; minor defects [MINDEF]; and total defects [TDEF]). The animals were subdivided into 3 age groups: G1 (0.8-2.0 years old), G2 (2.1-3.6 years old), and G3 (3.7 and 6.4 years olds). The physiological signs observed included duration of prelude (12.1 ± 4.1 minutes), time to collect semen (5.2 ± 1.8 minutes), nasonasal or genital contact behavior (71.6%), saliva emission (85.2%), urination during prelude (10.1%), penile exposure before collection (26.6%), flank stimulus (81.7%), chewing behavior (95.3%), and biting of the female or dummy (74.6%). The mean values of TL, TW, and TV were 11.8 ± 2.2 cm, 6.2 ± 1.3 cm and 754.1 ± 283.5 cm3, respectively. The older animals had the highest mean values of testicular measurements (P < 0.05) but the lowest mean values of CONCML and CONCT (P < 0.05). All the animals presented similar patterns of ejaculates (P > 0.05); the mean values of VOL, VOLGEL, MOT, VIG, and CONCT were 149.1 ± 51.1 mL, 29.7 ± 10.0 g, 76.2% ± 9.5%, 3.3 ± 0.5, and 29.4 ± 19.5 × 109 total sperm in the ejaculate, respectively. The prevalence rates of defects were 5.9% ± 2.6% for MAJDEF, 10.2% ± 4.0% for MINDEF, and 16.2% ± 5.5% for TDEF; all animals were classified as being sound for breeding. The assessed characteristics were similar to those observed in swine of commercial lineages and within the standards established by the Brazilian College of Animal Reproduction for the species.  相似文献   

11.
A total of 94 pigs from seven groups considered as lean (boars from a synthetic line and the Pietrain breed), conventional (boars, gilts, and barrows from the Large White breed), fat (barrows from the Meishan x Large White cross), or obese (Meishan barrows) were serially slaughtered between 12 and 110 kg BW. Carcasses were dissected into muscle, bone, skin, and fat, which was further separated into subcutaneous, intermuscular, and kidney fats. Subcutaneous fat accounted for 60 to 70% of body fat and intermuscular fat for 20 to 35% of body fat. Relative to total fat, intermuscular fat grew more slowly (allometric growth coefficients generally < 1), subcutaneous fat at the same rate (b close to 1), and kidney fat more rapidly (1.12 < b < 1.33). The leaner the animals genetically, the higher the proportion of intermuscular fat in total fat. The ratio of intermuscular to subcutaneous fat varied from .31 in Meishan barrows to .66 in Pietrain boars. Overall, the ratio of intermuscular fat to muscle weight or body weight was positively related to the development of total fat. However, Pietrain pigs were unique in having a high development of intermuscular fat. The present results suggest that 1) the genetic controls of the development of intermuscular and subcutaneous fat are partially independent and 2) the development of intermuscular fat may be determined at an early stage, before 20 kg BW.  相似文献   

12.
ESR2 is involved in oestrogen-related apoptosis in cell cycle spermatogenesis but their effects have not yet confirmed in pig. Therefore, this study was aimed to investigate the association of ESR2 polymorphism with sperm quality and boar fertility traits and to analyse the ESR2 mRNA and protein expressions in boar reproductive tissues. DNA samples from 203 Pietrain (PI) and 100 Pietrain × Hampshire (PIHA) pigs with records of sperm quality [sperm concentration (SCON), motility (MOT), semen volume (VOL), plasma droplet rate (PDR) and abnormal spermatozoa rate (ASR)] and fertility [non-return rate (NRR) and number of piglet born alive (NBA)] traits were available. A SNP in coding region of ESR2 g.35547A>G in exon 5 was associated with MOT and PDR in the PI and with SCON, VOL, MOT and PDR in PIHA population. For mRNA and protein expression study, a total of six boars were divided into two groups with group I (G-I) and group II (G-II) where G-I characterized for relatively a better sperm quality according to the mean of two groups. mRNA expression was higher in brain and testis than that in all parts of epididymis. Both qRT-PCR and western blot analysis revealed that the ESR2 gene expression and protein expression were significantly higher in testis collected from G-II compared with that of G-I boars. Moreover, ESR2 protein localization in germ cell, Leydig and Sertoli cells, epithelial cells and spermatozoa was remarkable, which indicated the important role of ESR2 in spermatogenesis process. These results might shed new light on the roles of ESR2 in spermatogenesis as candidate for boar fertility, but still the lack of association across populations should be considered.  相似文献   

13.
The aim of this study was to investigate the influence of boar breed on the optimal concentration of gamma‐oryzanol on the qualities of cryopreserved boar semen. Semen was collected from 20 boars (10 Duroc, 5 Large white and 5 Landrace boars). The semen sample was divided into five groups (A–E) according to the concentration of gamma‐oryzanol in extender II, that is 0, 0.08, 0.16, 0.24 and 0.32 mm , respectively. The semen was cryopreserved by nitrogen vapour and storage in nitrogen tank (?196°C). After storage for a week, samples were thawed at 50°C for 12 s and evaluated for progressive motility, sperm viability and acrosome integrity. The results demonstrated that gamma‐oryzanol significantly improved progressive motility, viability and acrosome integrity of frozen–thawed boar semen. Considering the influence of breeds on the optimal concentration of gamma‐oryzanol, for Duroc boar, gamma‐oryzanol at 0.16 mm (group C) yielded the highest percentage of progressive motility, sperm viability and acrosome integrity. For Large white and Landrace boars, gamma‐oryzanol at 0.24 mm (group D) showed a significantly higher percentage of progressive motility, viability (not significant in Landrace) and acrosome integrity than other concentrations. In conclusion, the optimal concentration of gamma‐oryzanol needed for boar semen cryopreservation in lactose–egg yolk (LEY) freezing extender is not only depended on individual boar but also breed of boar, that is 0.16 mm for Duroc and 0.24 mm  for Large white and Landrace.  相似文献   

14.
Lactoferrin is regulated by estrogen in the female reproductive tract and evidence in immature mice suggests that it may be estrogen regulated in males as well. The estrogen regulation of lactoferrin in the epididymis of the boar, a high estrogen-producing male, is unknown. This study was designed to test the hypothesis that lactoferrin expression in the boar epididymis is regulated by estrogen. Twenty-one littermate pairs of boars were treated with vehicle or Letrozole, an aromatase inhibitor, from 1 week of age until castration at 2 through 8 months. Epididymal tissue was collected at castration and fixed for immunolocalization of lactoferrin. Epididymal and testicular tissues were also collected from five mature boars (1-2.5 years) and fixed for immunocytochemistry (ICC). Lactoferrin was localized in the principal cell cytoplasm of the caput, corpus and cauda of developing boars but only in the corpus and cauda of mature boars. Basal cells were negative for lactoferrin. Sperm in the corpus and cauda was also positive for lactoferrin. The efferent ducts and testes were negative for lactoferrin. Intensity of lactoferrin immunostaining increased with age in the corpus and cauda regardless of treatment. Reduced endogenous estrogen in the epididymis during development did not affect the intensity of immunostaining between control and Letrozole-treated animals. Lactoferrin expression in the epididymis of the developing boar does not appear to be regulated by estrogen.  相似文献   

15.
OBJECTIVE: To determine whether testicular needle biopsy is detrimental to testicular function in clinically normal bulls. DESIGN: Prospective study. ANIMALS: 6 mixed-breed mature bulls. PROCEDURE: A randomly selected testicle from each bull was biopsied with a 14-gauge needle biopsy instrument. Bulls were then evaluated over a 90-day period for changes in scrotal temperature and thermal patterns, ultrasonographic appearance, and quality of spermatozoa. At the end of the 90-day study, bulls were castrated, and testicles were examined grossly and histologically. RESULTS: Changes were detected in scrotal temperatures and thermal patterns and in the breeding soundness examination results during the first 2 weeks of the study. However, there were no long-term changes in semen quality over the course of the experiment. Hyperechoic areas were detected on ultrasonographic examination and corresponded to the areas of penetration by the biopsy instrument. Microscopic lesions that were indicative of testicular dysfunction were not found. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate that testicular biopsy is a safe procedure in bulls. Testicular biopsy could possibly be used to further examine bulls that have less than satisfactory results for breeding soundness examinations.  相似文献   

16.
本试验旨在研究谷胱甘肽过氧化物酶6（glutathione peroxidase 6,GPx6）在大白公猪附睾细胞中的表达和定位,并探究其与公猪繁殖性能的相关性。选取15月龄的公猪和母猪各3头,取睾丸、附睾、前列腺、尿道球腺、精囊腺、卵巢和输卵管,提取蛋白,通过蛋白免疫印迹和免疫组化（IHC）检测组织和细胞中GPx6蛋白的表达和定位;根据评定大白公猪受精能力的数学模型,按照公猪配种胎次≥20胎、3次配种公猪为同一头的标准,筛选并采集符合要求的20头公猪精液,同时,统计相对应的1 279头母猪的生产成绩,计算得到公猪繁殖性能指标（包括窝产总仔数、窝产活仔数、分娩率和繁殖力）。提取精子蛋白和精清蛋白,通过BCA和ELISA检测精子和精清中GPx6蛋白的含量。使用SPSS软件的独立样本t检验及单因素方差分析（one-way ANOVA）,进行差异显著性分析,用双变量Pearson进行相关性分析,P<0.05表示差异或相关显著。结果表明,GPx6蛋白在附睾中高表达,IHC结果显示,GPx6蛋白在附睾的顶细胞、基底细胞、晕细胞、主细胞和精子中表达,在肌样细胞中不表达;精清蛋白中GPx6的含量是精子蛋白的7倍,精液中GPx6蛋白的含量与窝产活仔数、窝产总仔数呈负相关关系。结果提示,GPx6在附睾的顶细胞、基底细胞、晕细胞、主细胞和精子中表达,且其在精液中的含量会影响公猪的繁殖性能,这为GPx6对公猪受精能力影响的研究奠定了理论和试验基础。  相似文献   

17.
The levels were assessed of testosterone in the blood plasma before and 90 minutes after i.v. application of 1 mg of synthetic LH-releasing hormone to 57 boars with disorders of sexual functions and to 43 boars without sexual dysfunctions. The group of animals with sexual disorders included boars with inferior ejaculate quality and low fertility (24 animals) and cases with disturbed sexual potency (33 boars). In animals with the studied changes of sexual functions, compared with boars without sexual dysfunctions, no statistically significant difference was found in the basal concentration of testosterone in the blood. LH-releasing hormone application increased significantly the testosterone levels in the group of boars without sexual disorders by 99.5% on an average and in the whole group of animals with changes in sexual functions approximately by only 65.8%. At the same time in the subgroup of inferior ejaculate quality and low fertility the post-application increase of testicular incretion reached 60.4% and in potency disorders 61.6% and was statistically insignificant in the latter. On the basis of these findings it was derived that in boars with reproduction deviations there existed a decreased incretion reserve of the system hypophysis - testicle and the involvement of this factor in the formation of the studied sexual disorders is assumed. The obtained results are discussed in view of the earlier findings about the incretion reserve of the testicles in boars with changes in sexual functions.  相似文献   

18.
This article studies the effect of a boar's birth season and breed on semen parameters and its further reproductive performance. Research material consisted of 72 boars from three breeds (24 Polish Large White PLW, 24 Polish Landrace PL, 24 Duroc × Pietrain D×P). During the whole period of the study, selected semen parameters were analysed: semen volume, spermatozoa concentration, total number of spermatozoa, total number of motile spermatozoa, number of insemination doses and also reproductive indicators: farrowing rate, total born litter size, total number of piglets born live and still, and average piglet weight. Boars born in the winter and summer months demonstrated the highest spermatozoa concentrations (383.25 and 392.37 × 106/ml), total number of spermatozoa (91.75 and 93.21 × 109), total number of motile spermatozoa (76.10 and 77.99 × 109) and number of insemination doses (24.53 and 24.89; p ≤0.01). Statistically lower values for these parameters were observed for boars born in the spring and especially in autumn (p ≤0.01). The significant impact of birth season on farrowing rate (p ≤ 0.05) and average piglet weight (p ≤ 0.05) was confirmed for PLW boars. For the PL breed, only the total number of piglets born live was proven to be significantly affected (p ≤ 0.05). No impact of birth season was shown on semen quality or reproductive performance for D×P boars. In our study, we showed that the birth season of a boar had a more impact on the level of semen parameters, and less on the reproductive performance indicators. The results indicated that both the quality of semen and reproductive performance varied in terms of the study factors, as well as between individual breeds of boars involved in the experiment.  相似文献   

19.
为提高贵州地方良种黔东花猪的繁殖性能,试验选取高繁品种太湖猪为父本,黔东花猪为母本,进行杂交,得到F1（♀）后分别与皮特兰（♂）、杜洛克（♂）杂交,获取不同组合F2,再以巴克夏为终端父本,测定不同组合F2（♀）繁殖性能。结果表明,黔东花猪、太湖猪、皮特兰杂交组合所得的母本在乳头数、初情期、初配日龄、初产及经产母猪产仔数、断奶后发情间隔期等指标均优于黔东花猪、太湖猪和杜洛克组合,是一种具有较高繁殖性能的黑猪母本材料,但在仔猪初生重、生长速度方面低于黔东花猪、太湖猪和杜洛克组合。  相似文献   

20.
Quadratic fitting was used to regress semen characteristics of 1441 samples consisting of 12‐month collection from 58 Duroc boars against animal age varied from 10 to 80 months. Data was divided into two groups of cool (14.0–22.7°C, RH 81.5%) and hot season (22.9–29.9°C, RH 86.6%), to test effects of age, season and their interactions. Results revealed that young boars of around 1 year old could endure the hot season. The endurance gradually diminished as animals grew. In the hot season animals exhibited peak performance at age around 33 month and it remained for 1 month, while cool‐season kept boars could last for 48 months from 16 months old onward. The reproductive longevity should be 51 month in a subtropical environment and it may extend to 70 month if heat stress can be avoided. The estimated total sperm contribution of a Duroc boar would be 1.8 times more when kept below 22°C than in a natural subtropical environment. It is concluded that to maintain Duroc boars as semen donor to at least 4 years of age is feasible in a subtropical environment and boar longevity could reach 6 years old if well kept in a temperate region.  相似文献   

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