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1.
Evidence is provided of seasonal changes in the rate of DNA fragmentation dynamics of sperm collected from goats Murciano-Granadina breed), in a Spanish Breeding Centre at 41°N latitude. Results show that the initial assessment of sperm DNA fragmentation (T0) was not sufficient to differentiate sperm DNA fragmentation of bucks collected at different times of the year (Kruskal–Wallis 2.399; P = 0.493). However, when thawed semen was subsequently incubated at 37 °C for periods of between 2 and 48 h, differences were recorded in the rate of sperm DNA fragmentation (r-SDF), that are indicative of seasonal changes in reproduction (Log Rank: Mantel–Cox; χ2 = 158.6; DF = 3; P < 0.001). Goat semen collected and cryopreserved in the Spanish winter and spring resulted in a poor post-thaw sperm DNA longevity and recorded a r-SDF of 0.8 and 1.3 per hour, after 48 h of incubation respectively. The r-SDF subsequently decreased to 0.16 and 0.36 per hour during summer and autumn. It is therefore, recommended that semen samples from Murciano-Granadina goats housed above the 40°N latitude be collected and cryopreserved in the summer and early autumn. This would result in a more stable DNA molecule, which is likely to improve the reproductive success. 相似文献
2.
This study compared the field fertility outcomes in frozen–thawed (FT) sperm from boar ejaculates with different freezability (good, GFE/poor, PFE) while testing the reliability of the post-cervical artificial insemination (post-CAI) in FT sperm. The assay was conducted over eight months with 86 weaned sows being inseminated by post-CAI. Every ejaculate in a total of 26 from 15 Piétrain boars was divided into a refrigerated semen portion (FS; control treatment) and a cryopreserved portion (FT sperm), and the ejaculates were in turn classified as GFE or PFE in function of the sperm progressive motility and viability at 240 min post-thaw. As result, one of four possible treatments was randomly given to each sow: FS-GFE, FS-PFE, FT-GFE and FT-PFE. The number of pregnant and farrowing sows in FT-GFE did not significantly differ from those of FS control treatments. Contrarily, the probabilities of pregnancy were two times lower after inseminations with FT-PFE (P < 0.05) compared to FT-GFE, which indicates that ejaculates with high post-thaw sperm progressive motility and viability are more likely to result in pregnancies than those with poor in vitro sperm function. There were no differences in litter size or the risk of backflow among treatments. Further trials are required to determine the optimal volume and concentration of FT sperm in post-CAI to obtain a more reliable method for farmers interested in cryopreserved sperm. 相似文献
3.
Padilha RT Magalhães-Padilha DM Cavalcante MM Almeida AP Haag KT Gastal MO Nunes JF Rodrigues AP Figueiredo JR Oliveira MA 《Theriogenology》2012,78(4):907-913
The objective was to evaluate the effects of insulin-like growth factor-I (IGF-I) on the quality and fertility of frozen/thawed ovine semen. Five rams (five ejaculates/ram) were used for evaluation of semen parameters. Before cryopreservation, ejaculates were divided into four aliquots and extended with Tris alone or supplemented with human IGF-I (50, 100, or 250 ng/mL). Semen was evaluated immediately after thawing (T0), after 1 h (T1) and 2 h (T2) post-incubation at 37 °C. The percentage of live cells (fluorescence analysis-calcein and ethidium), acrosome integrity (NAR) and motility were analyzed, and hypo-osmotic swelling tests (HOST) were used to evaluate membrane resistance. In addition, AI was performed using 121 ewes to compare the optimal concentration of IGF-I vs. Tris alone on pregnancy rates after laparoscopic insemination. Pregnancy diagnosis was performed by transrectal ultrasonography. After 1 and 2 h post-incubation, in every group, percentage motile sperm, NAR and HOST decreased compared to semen at T0. Motility was higher (P < 0.05) in the IGF-I 100 and IGF-I 250 groups when compared to the IGF-I 50 and Tris groups (76.2 and 74.4% vs. 66.2 and 64.4 percent, respectively) at T0, after 1 h (67 and 63.6% vs. 56.2 and 54.7%) and 2 h post-incubation (58.2 and 55.8% vs. 48 and 47.2%). Furthermore, viability was higher (P < 0.05) in the insulin-like growth factor-I (IGF-I) 100 and IGF-I 250 groups than in the IGF-I 50 and Tris groups (88.7 and 88.3% vs. 76.6 and 77.6%, respectively) at T0. There was no difference (P > 0.05) in NAR or hypo-osmotic swelling tests (HOST) among groups. There were no differences (P > 0.05) in fertility between the IGF-I 100 and Tris groups. In conclusion, IGF-I improved subjective sperm motility and structural integrity of the plasma membrane without a significant effect on 45-day pregnancy rates after laparoscopic insemination of ewes with frozen-thawed semen. 相似文献
4.
We have reported that artificial insemination (AI) with frozen-thawed boar semen supplemented with caffeine increased the number of uterine sperm by inhibiting the migration of polymorphonuclear leukocytes (PMNs) into the uterine lumen, thereby improving the fertility of gilts and sows. The objective of the present study was to examine the effects of the addition of the antioxidant beta-mercaptoethanol (bME) and caffeine to the thawing solution on the function of frozen-thawed sperm, on the phagocytic activity of PMNs for sperm, and on the fertility of sows after AI. When frozen-thawed sperm were cultured in the presence of 25 or 50 μm bME, sperm capacitation and spontaneous acrosome reactions were inhibited (P < 0.01). There was no effect of bME on phagocytic activity of PMNs for sperm in vitro. When hormonally treated (400 IU of equine chorionic gonadotropin + 200 IU of human chorionic gonadotropin) weaned sows experienced a single intrauterine insemination with frozen-thawed sperm (25 × 108 sperm per 50 ml dose) 40 h after subsequent hCG administration, pregnancy and farrowing rates were unaffected by the addition of 50 μm bME (pregnancy rate, 20 vs 21% in controls; farrowing rate, 20 vs 21%; n = 15 and 14, respectively). However, litter size tended to be higher than in the presence of 50 μm bME compared to its absence (10.0 ± 1.0 vs 5.7 ± 1.5, respectively; P < 0.07). Thus, the addition of bME to the thawing solution containing caffeine could be of benefit for improving the function of frozen-thawed sperm without influencing the phagocytic activity of PMNs for sperm. Although there were no statistically significant effects of bME on pregnancy or farrowing rates, the litter size tended to be higher in the sows subjected to a fixed-time single AI treatment with synchronized ovulation. 相似文献
5.
J.E. Park S.G. Hong J.T. Kang H.J. Oh M.K. Kim M.J. Kim H.J. Kim D.Y. Kim G. Jang B.C. Lee 《Theriogenology》2009,72(5):721-730
Since the establishment of production of viable cloned dogs by somatic cell nucleus transfer, great concern has been given to the reproductive abilities of these animals (Canis familiaris). Therefore, we investigated reproductive activity of cloned dogs by (1) performing sperm analysis using computer-assisted sperm analysis and early embryonic development, (2) assessing reproductive cycling by measuring serum progesterone (P4) levels and performing vaginal cytology, and (3) breeding cloned dogs using artificial insemination. Results showed that most parameters of sperm motility in a cloned male dog were within the reference range, and in vivo–matured oocytes from a noncloned female were successfully fertilized by spermatozoa from a cloned male dog and develop normally to the 8-cell stage. Three cloned female dogs displayed normal patterns of P4 levels and morphologic changes of the vaginal epithelium. Two cloned female dogs became pregnant using semen from a cloned male dog and successfully delivered 10 puppies by natural labor. In conclusion, these data demonstrated that both cloned male and female dogs are fertile, and their puppies are currently alive and healthy with normal growth patterns. 相似文献
6.
Seasonal variations in the volume of milk in Norwegian goat dairy farming complicate the production of brand goat cheeses. In the specialised goat dairy farming system most kids are culled shortly after birth without utilising the meat. In this paper the farm economics of an alternative system with altered period of kidding (currently from January to March) combined with the production of meat and cashmere fibre, is examined. May kidding combined with raising the kids for 8 or 20 months yielded the most promising economical return. Raising the kids for 1 year is also profitable when kidding takes place in February while December kidding seems to perform best with the present system of culling the kids right after birth. Cashmere fibre production seems to be profitable on Norwegian dairy goat farms and fibre and meat could become an option in countries seeking to improve incomes on dairy goat farms. Compared to the present system the changes would also be favourable from an animal welfare point of view. 相似文献
7.
Artificial insemination (AI) and semen freezing have become services available to dog owners worldwide, and the demand for services to freeze semen is increasing. In other canids such as the fox, the fur industry utilizes fresh or frozen semen to artificially inseminate vixens to produce pelts. Clearly, AI facilitates the use of a male to sire several females by diluting the ejaculate, increases breeding hygiene, and allows crossing between species with slightly different breeding seasons. The African wild dog (Lycaon pictus) is currently considered by the World Conservation Union (IUCN) as one of most endangered canids. In captive populations of African wild dogs, semen has been frozen with encouraging results, using a standard cryopreservation protocol for domestic dogs, but successful AI has not been reported. In wolves, there is one report regarding the live birth of an offspring after intravaginal AI of a deslorelin-induced estrous female. In 2005, three Mexican gray wolf females were artificially bred by intrauterine insemination with freshly collected semen from unrelated males, and all females whelped. Artificial insemination may be vaginal, intrauterine or intratubal, and the semen may be fresh, fresh and chilled (diluted), or frozen-thawed, and the source of semen may be epididymal or ejaculated. In the domestic dog, the results are good to excellent for AI with all three types of processed semen when the source is ejaculated semen, whereas epididymal sperm still yields poorer results. Species differences in female physiology, as well as differences in the cryotolerance of the sperm from various canid species, warrant further research and development. 相似文献
8.
R.S. Uzêda A.M. Pinheiro S.Y. Fernndez M.C.C. Ayres L.F.P. Gondim M.A.O. Almeida 《Small Ruminant Research》2007,70(2-3):257-259
Sera from 384 dairy goats in nine herds from Bahia State, Brazil, were assayed for Neospora caninum antibodies using an indirect immunofluorescent antibody test (IFAT). Animals were selected and divided in groups by age and breed. Antibodies against N. caninum were found in 15% (58/384) of goats. Serum titers ranged from 1:100 to 1:3200. There was no significant difference between the age groups. Seroprevalence was higher in Alpine breed (24%) than in Saanen (14%) and Nubian (3%) breeds. The 58 N. caninum-positive sera were also tested for Toxoplasma gondii and 71% of the samples reacted solely to N. caninum. These results indicate that N. caninum infection is common in goat herds in Bahia. 相似文献
9.
Field trials were conducted to increase fertility with AI of flow-sorted, sexed bovine sperm. In the first trial, a novel competitive fertilization approach was used to compare pressures (30 psi vs 50 psi) for sorting sperm. Both X- and Y-sperm were sorted to approximately 95% purity at 30 and at 50 psi; X-50 + Y-30 (and the converse) were mixed in equal numbers for AI of heifers. Fetal sex divulged which treatment produced the pregnancy; 82% of pregnancies resulted from the 30 psi treatment (P < 0.05). Based on a similar approach, a new-pulsed laser did not damage sperm any more than the previous standard continuous wave laser. In a large field trial, sorting sperm at 40 psi increased pregnancy rates in heifers relative to 50 psi (42.3% vs 34.1%, n = 367/group, P < 0.05). Storing sperm for 20 h before sorting at 40 psi decreased pregnancy rates from 42.3% (n = 367) to 36.8% (n = 368; P < 0.05). Breeding heifers with sexed sperm 55-56 h after CIDR removal and PGF2α resulted in 34% (n = 32) pregnant, compared to 49% (n = 35) with fixed-time insemination 67-68 h after CIDR removal (P > 0.1). Lactating dairy cows pre-screened for normal reproductive tracts when OvSynch injections (GnRH, prostaglandin, GnRH) were initiated, had similar (P > 0.1) pregnancy rates to timed AI, with 10 × 106 sexed sperm (43.9%, n = 57), 2 × 106 sexed sperm (40.5%, n = 57) and 10 × 106 unsexed control sperm (55.6%, n = 58). A final field trial with unselected, lactating dairy cows resulted in similar pregnancy rates for 2 × 106 sexed sperm in 0.25 mL straws (25.0%, n = 708) and 0.5 mL straws (24.4%, n = 776), but lower (P < 0.05) than unsexed control sperm (37.7%, n = 713). Younger cows and those >84 days in milk had the highest pregnancy rates for both sexed and unsexed sperm. These studies improved sperm sexing procedures, and provided insight into appropriate commercial use of sexed sperm. 相似文献
10.
The aims of this study were to test the presence of discrete sperm subpopulations in Florida goat ejaculates using a computer-assisted sperm analysis (CASA) system and to establish the relationship between the distribution of the subpopulations found and individual buck, total motility, and sperm concentration. Clustering methods and discriminant analysis were applied to identify motile sperm subpopulations within the semen samples. Principal component analysis revealed that three principal components represented more than the 88% of the variance. After the cluster analysis was performed four motile sperm subpopulations were identified. Subpopulation 1 consisted of rapid and linear sperm (39.84%), Subpopulation 2 consisted of slow but linear spermatozoa (33.23%), Subpopulation 3 consisted of rapid, high ALH but non-linear spermatozoa (14.63%), and Subpopulation 4 consisted of slow and non-linear spermatozoa (12.31%). There were significant differences in the distribution of the four subpopulations (P < 0.001) as well as in the percentage of total motility and the overall sperm concentration (P < 0.05) in fresh ejaculates among the four bucks tested. In conclusion, four well-defined motile sperm subpopulations were identified in Florida goat ejaculates. The relationship between the distribution of the sperm subpopulations and individual buck, total motility, and sperm concentration shows that the spermatozoa of each have different motility patterns. Therefore, the study of discrete subpopulations of motile spermatozoa could lead to a substantial increase in information acquired during caprine semen analysis. 相似文献
11.
Serpil Sar?özkan Mustafa Numan Bucak Pürhan Barbaros Tuncer Ali Bilgen 《Cryobiology》2009,58(2):134-890
Oxidative stress significantly damages sperm functions such as motility, functional integrity, endogenous antioxidant enzyme activities and fertility due to lipid peroxidation induced by reactive oxygen species (ROS). The aim of this study was to determine the effects of antioxidants such as taurine and cysteine in Bioxcell® extender on standard semen parameters, fertilizing ability, lipid peroxidation (LPO) and antioxidant activities comprising reduced glutathione (GSH), glutathione peroxidase (GSH-Px), catalase (CAT) and superoxide dismutase (SOD) after the cryopreservation/thawing of bull semen. Nine ejaculates for each bull were included in the study. Three groups, namely taurine (2 mM), cysteine (2 mM), and control, were designed to analyze the antioxidants in Bioxcell®. Insemination doses were processed so that each 0.25-ml straw contained 15 × 106 sperm.The addition of cysteine led to higher motility, compared to the other groups (P < 0.001). Cysteine showed a greater protective effect on the percentages of acrosome damage and total abnormalities in comparison to the other groups (P < 0.001). No significant differences were observed in hypo-osmotic swelling test (HOST), following supplementation with antioxidants during the freeze-thawing process. No significant difference was observed in non-return rates among groups. In biochemical assays, the additives did not show effectiveness on the elimination of malondialdehyde (MDA) formation and maintenance of GSH and GSH-Px activities, when compared to controls. CAT activity (35.1 ± 8.1 kU/g) was demonstrated to be significantly higher upon the addition of 2 mM taurine (P < 0.001), while the level of MDA increased, indicating oxidative stress in this group. SOD activity (21.4 ± 2.9 U/g protein) was significantly elevated in the group with cysteine, compared to the other groups (P < 0.001). 相似文献
12.
The aim of this study was to investigate the reasons for differences in field fertility of bulls following insemination with frozen-thawed semen. The study was carried out in two separate parts over two years and comparisons were made between 5 high and 4 low fertility Holstein Friesian bulls as determined by their either 90 day non-return rate (Year 1) or calving rate (Year 2). Two high fertility Limousin bulls were included in Year 1 for comparative purposes. The ability of sperm from each bull to penetrate artificial mucus was assessed (Year 1 = 7 replicates; Year 2 = 5 replicates). Glass capillary tubes (2 per bull per replicate) were filled with artificial mucus and incubated with sperm stained in 1% Hoechst 33342 for 30 min at 37 °C. The number of sperm were subsequently counted at 10 mm intervals along the tube between 40 and 80 mm markers. Sperm mitochondrial activity of each bull was assessed by the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide) assay (4 replicates in each year). Sperm were incubated with MTT for 1 h at 37 °C following which the absorbance of formazan was read using a spectrophotometer. Sperm viability after thawing was assessed for each bull using a live/dead sperm viability kit (Year 1 = 3 replicates; Year 2 = 4 replicates). A minimum of 250 cells were assessed per bull in each replicate and classified as either live or dead. Finally, the ability of sperm to fertilize oocytes in vitro and their ability to develop to blastocyst stage embryos were assessed (5 replicates in each year involving 220 to 306 oocytes per bull). Data transformation to normalize residuals was required for mucus sperm penetration (square root) and IVF (cleavage and blastocyst rate) results (arcsin). The mean number of sperm counted at each 10 mm mark between 40 and 80 mm was higher in the high fertility (56.0; 95% CI 39.5 to 75.3) compared to the low fertility (42.9; 95% CI 29.3 to 59.1) Holstein Friesian bulls but the difference did not reach formal significance (P = 0.09). Fertility status had no effect on the ability of sperm to reduce MTT to formazan (mean absorbance 0.34 ± 0.051 and 0.30 ± 0.044) or on the percentage of live sperm per straw (mean 47.3 ± 5.47 and 32.4 ± 4.66) for high and low fertility Holstein Friesian bulls respectively. Oocyte cleavage rate following insemination with sperm from high fertility Holstein Friesian bulls was significantly higher than with sperm from low fertility Holstein Friesian bulls [76.7% (95% CI 60.9 to 89.4) and 55.3 (95% CI 40.4 to 69.7) respectively, P = 0.04]. There was no significant effect of bull fertility on blastocyst rate [34.7% (95% CI 21.1 to 49.6) and 24.2 % (95% CI 14.1 to 36.0) for the high and low fertility Holstein Friesian bulls, respectively; P = 0.2]. In conclusion, sperm from high fertility bulls tended to be more effective in penetrating artificial mucus and to have an increased ability to fertilize oocytes in vitro; however, once fertilization occurred subsequent embryo development was not significantly affected by fertility status. 相似文献
13.
The measurement of the ATP content of fresh semen is as accurate as the estimation of sperm motility by conventional methods in discriminating between semen of fertile versus subfertile men. The ATP content of frozen thawed donor semen is correlated with the probability of conception per cycle of insemination. Exact quantification of cytotoxic sperm antibodies in serum is possible with the adenosine-triphosphate-release-cytotoxicity test, since measurement is free of the bias of microscopic examination. The procedure has been simplified by testing only one serum dilution and calculating the ‘sperm toxicity index’. 相似文献
14.
Gómez-Martín A Corrales JC Amores J Sánchez A Contreras A Paterna A De la Fe C 《Theriogenology》2012,77(6):1252-1256
Many goat artificial insemination (AI) centers in Spain have adopted new measures to control contagious agalactia (CA). To avoid the introduction of male goats carrying mycoplasma organisms subclinically in their external ear canal (auricular carriers) in these centers, two ear swabs and a blood sample are obtained from all candidate animals for polymerase chain reaction (PCR), culture (swabs) and serologic tests to detect the presence of mycoplasmas. In addition, the semen produced at these centers is routinely cultured and PCR tested also to detect the presence of mycoplasmas. One y after the introduction of this program, we tested 48 ear swabs and 24 blood samples from 24 candidates for admission to these AI Centers. Three of these ear swab samples (3/48, 6.25%) scored positive for the presence of mycoplasmas; Mycoplasma agalactiae (Ma) was detected in two samples and Mycoplasma mycoides subsp. capri (Mmc) in one. All animals were serologically negative for Ma. Also, out of 173 semen samples obtained from 137 admitted animals (2 and 3 samples were obtained in 16 and 10 bucks, respectively), one (1/173, 0.56%) was positive for Mmc. Our findings suggest that ear swab and semen samples are useful tools to control CA at AI Centers. The introduction of this program has also resulted in the first detection of Mmc in semen from a naturally infected goat, confirming the ability of this mycoplasma to colonize the reproductive tract of male goats. These results highlight the need to improve control measures in semen producing centers to minimize the risk of CA transmission. 相似文献
15.
Single mating productivities (used as estimates of the relative number of sperm transferred) are highly correlated with several parameters used to quantify sperm competition in D. melanogster. Matings that result in the transferal of large numbers of sperm are associated with longer delay of female remating than are matings that transfer fewer sperm. Males that transfer larger numbers of sperm also suffer a smaller proportional reduction in reproductive success (smaller COST) than males transferring fewer sperm. The number of sperm transferred by a female's second mate is not related to the COST to the first male. However, there is a high positive correlation between the number of sperm transferred by the second male and P2 (the proportion of second male progeny following female remating). Thus, large sperm numbers apparently increase the reproductive success of males whether they mate with virgin or non-virgin females. Because female receptivity mediates these events, there is no need to invoke sperm displacement to explain the reproductive outcome of female remating.The timing of female remating is evaluated in terms of a receptivity-threshold model. This model suggests that female receptivity returns when some small, relatively constant, number of sperm remain in storage. 相似文献
16.
Pamela Wiener Judith Alexis Smith Alyson Margaret Lewis John Arthur Woolliams John Lewis Williams 《遗传、选种与进化》2002,34(2):221-232
In this paper, we examined the effects of an 11-bp mutation within the GDF-8 gene, originally identified in Belgian Blue cattle, in the South Devon breed. The mutation was found at moderate frequency (0.37) in the South Devon population. We quantified the effects of this mutation on growth, body composition and calving traits in South Devon cattle. We found that the mutation significantly increased muscle score and calving difficulty and decreased fat depth. The mutation did not significantly affect weight at 200 and 400 days or muscle depth. Its effect on muscle score and fat depth was additive while its effect on calving difficulty was recessive. The mutation accounted for a significant proportion of the phenotypic variance in muscle score and calving difficulty. There was an economic benefit of the mutation for this data set, however, calculations were sensitive to changes in the parameter values. Additional data would be required to refine these calculations. 相似文献
17.
The process of sperm incorporation into starfish (Asterias amurensis) oocytes was examined by electron and fluorescence microscopy. The fertilization cone began to form at the place where the acrosomal process fused with the egg surface and developed into an inverted conical mass containing a small amount of electron-dense cytoplasm. Microfilaments, which stained with NBD-phallacidin, were detected in the fertilization cone. Microvillar protrusions from the fully grown fertilization cone engulfed the sperm head outside the fertilization membrane. The sperm organelles were incorporated into the egg cortex with the absorption of the protrusions. Cytochalasin B inhibited sperm incorporation, fertilization cone formation, and actin filament organization. It is suggested that the development and reduction of the fertilization cone, which depend on the functioning of microfilaments, are necessary for sperm incorporation in starfish. 相似文献
18.
Effects of environmental factors, age and genotype on sperm production and semen quality in Bos indicus and Bos taurus AI bulls in Brazil 总被引:2,自引:0,他引:2
Brito LF Silva AE Rodrigues LH Vieira FV Deragon LA Kastelic JP 《Animal reproduction science》2002,70(3-4):181-190
The effects of ambient temperature and humidity, month, age and genotype on sperm production and semen quality in AI bulls in Brazil were evaluated. Data from two consecutive years were analyzed separately. Seven Bos indicus and 11 Bos taurus bulls from one artificial insemination (AI) center were evaluated in Year 1 and 24 B. indicus and 16 B. taurus bulls from three AI centers were evaluated in Year 2. Ambient temperature and humidity did not significantly affect sperm production and semen quality, probably because there was little variation in these variables. Month accounted for less than 2% of the variation in sperm production and semen quality. Increased bull age was associated with decreased sperm motility (P<0.10) and increased minor sperm defects (P<0.001) in Year 1. B. indicus bulls had greater (P<0.005) sperm concentration than B. taurus bulls in both years (1.7×109/ml versus 1.2×109/ml in Year 1 and 1.6×109/ml versus 1.2×109/ml in Year 2, respectively). Ejaculate volume was not significantly affected by genotype in Year 1 (6.6 ml versus 6.9 ml in B. indicus and B. taurus bulls, respectively), but B. indicus bulls had greater (P<0.05) total (11.4×109 versus 8.2×109) and viable (6.7×109 versus 4.9×109) numbers of spermatozoa in the ejaculate than B. taurus bulls. In Year 2, B. taurus bulls had greater (P<0.05) ejaculate volume than B. indicus bulls (8.2 ml versus 6.7 ml, respectively) and total and viable number of spermatozoa in the ejaculate were not significantly different between genotypes (10.3×109 versus 9.1×109 and 6.1×109 versus 5.4×109 in B. indicus and B. taurus bulls, respectively). Sperm motility was not significantly affected by genotype (mean, 59%). In Year 1, B. indicus bulls tended (P<0.10) to have more major sperm defects and had more (P<0.05) total sperm defects than B. taurus bulls (11.8% versus 8.7% and 13.6% versus 10.0%, respectively). In Year 2, B. indicus bulls tended (P<0.10) to have more total sperm defects than B. taurus bulls (16.2% versus 13.3%, respectively). In conclusion, neither ambient temperature and humidity nor month (season) significantly affected sperm production and semen quality. B. indicus bulls had significantly greater sperm concentration and B. taurus bulls had significantly fewer morphologically defective spermatozoa. 相似文献
19.
The main aims of the present study were to compare the pregnancy rate (PR), regular returns-to-estrus, and calving interval of a CO-Synch + controlled internal drug release (CIDR) device, commonly used to synchronize ovulations in beef cows, with the classical Ovsynch protocol in high-producing dairy cows. Holstein-Friesian cows (n = 128) from six commercial dairy herds, ≥40 days postpartum and not previously inseminated, were randomly assigned to one of two treatments. Cows submitted to Ovsynch protocol (group OS as control group; n = 66) received 10 μg of a GnRH analogue 7 days before and 48 hours after 25 mg PGF2α, followed by artificial insemination (AI) 16 hours after the second GnRH administration. Cows submitted to CO-Synch + CIDR (1.38 g of progesterone) inserted for 7 days beginning at the first GnRH administration (group CoS + CD; n = 62) had the second administration of GnRH concurrent with AI, 64 hours after CIDR removal/PGF2α administration. Nonpregnant cows with return-to-estrus between 18 and 24 days after first AI were reinseminated (second AI). Logistic regressions were used to analyze PR and returns-to-estrus. No effect of group or herd was observed in PR at first timed AI. However, the sum of cows pregnant at first AI and nonpregnant cows with regular returns-to-estrus and the total PR (first + second AI) were influenced by group treatment. Overall, cows of group CoS + CD (total PR = 56.5%) were 2.1 times more likely to became pregnant after AI and until first regular returns-to-estrus than cows of group OS. The calving interval was lower in group CoS + CD (425.9 ± 78.8 days; ±SD) than in group OS (475.3 ± 83.7 days). The CO-Synch + CIDR protocol was reliable to use in dairy herds and provided reproductive advantages when compared with Ovsynch protocol. 相似文献
20.
Milan ?ezá? 《Proceedings. Biological sciences / The Royal Society》2009,276(1668):2697-2701
The males of invertebrates from a few phyla, including arthropods, have been reported to practise traumatic insemination (TI; i.e. injecting sperm by using the copulatory organ to penetrate the female''s body wall). As all previously reported arthropod examples have been insects, there is considerable interest in whether TI might have evolved independently in other arthropods. The research reported here demonstrates the first case of TI in the arthropod subphylum Chelicerata, in particular how the genital morphology and mating behaviour of Harpactea sadistica (Řezáč 2008), a spider from Israel, has become adapted specifically for reproduction based on TI. Males have needle-like intromittent organs and females have atrophied spermathecae. In other spiders, eggs are fertilized simultaneously with oviposition, but the eggs of H. sadistica are fertilized in the ovaries (internal fertilization) and develop as embryos before being laid. Sperm-storage organs of phylogenetically basal groups to H. sadistica provide males with last male sperm priority and allow removal of sperm by males that mate later, suggesting that TI might have evolved as an adaptive strategy to circumvent an unfavourable structure of the sperm-storage organs, allowing the first male to mate with paternity advantage. Understanding the functional significance of TI gives us insight into factors underlying the evolution of the genital and sperm-storage morphology in spiders. 相似文献