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1.
The highly polymorphic genes within the major histocompatibility complex (MHC) not only play a major role in immunity resistance, but also seem to provide hints for mate choice in some animal populations. In the present study we investigated MHC‐related mate choice in a small natural population (group size 40–55 individuals) of a polygynous primate, the Sichuan snub‐nosed monkey (Rhinopithecus roxellana). We found that there was no evidence either for MHC‐disassortative mating, or for females to mate with males based on MHC heterozygosity or specific alleles. Nevertheless, of the 11 alleles identified, we found that the frequencies of 2 alleles, Rhro‐DRB2 (P < 0.01) and Rhro‐DRB5 (P < 0.05) were higher in offspring than in their parents. These findings suggest that MHC‐DRB in this population of R. roxellana is unlikely to be associated with mating preferences. Limited female opportunities for mate choice are likely due, in part, to the harem breeding structure present in R. roxellana, and the relatively small number of resident adult males in our study band (N = 4–6). In addition, we suggest that differences in the frequency of particular alleles across generations may be linked to parasite resistance in a fluctuating environment; however, confirmation of this finding requires further study.  相似文献   

2.
The invasive B whitefly and the indigenous ZHJ2 whitefly in China of the Bemisia tabaci complex represent two previously allopatric cryptic species. Laboratory experiments have shown that the invasive B can displace the indigenous ZHJ2. Here, we observed the mating behavior and mating interactions between B and ZHJ2 to elucidate the behavioral mechanisms underlying their competition. The 2 species are able to mate with each other, although at a significantly lower frequency than that between males and females within the same species. Heterospecifically-mated females produce only male progeny, indicating reproductive isolation. Heterospecific mating had only a marginal effect on reproduction of females in either species. Detailed observations on mating interactions between the 2 species showed that B had higher sexual activity than ZHJ2. B males were more likely to interrupt courtships initiated by rival males than ZHJ2 males. Compared with ZHJ2 males, B males were also more likely to successfully interrupt courtships initiated by rival heterospecific males than by males of the same species. In addition, B males guarded B females post-copulation, whereas ZHJ2 males did not. When the 2 species co-occurred, the behavioral differences and interactions between them resulted in an increased proportion of females produced in the offspring of B but reduced proportion of females in the progeny of ZHJ2. These asymmetric mating interactions might be an important mechanism underlying the displacement of ZHJ2 by B. Our study shows that reproductive interference might contribute to the competitive exclusion between closely related species during biological invasions.  相似文献   

3.
Virgin females of both Boophilus decoloratus and Boophilus microplus, when mated with males of the other species, subsequently produced sterile eggs. Counts of spermiophore capsules in female seminal receptacles showed that the males of both species will mate with the females of both species and that B. microplus males show a slightly greater, but statistically insignificant, mating capacity than B. decoloratus males. South African B. microplus females, when mated with an Australian strain of B. microplus males, produced a 62% yield of viable hybrid progeny while the reciprocal cross produced only a 1,82% hatch of non-viable larvae. The hybrids were sterile when interbred and no hatch resulted when the Fl males were backcrossed with parent females. The reciprocal backcross of hybrid Fl females to parent males resulted in a low percentage hatch of non-viable larvae.  相似文献   

4.
Inter‐group conflicts are common among many group‐living animals and involve potentially complex motivations and interactions. Mammals living in multilevel societies offer a good opportunity to study inter‐group conflicts. This study is the first to explore the function of sex‐specific participation during inter‐group conflicts within a multilevel society at the individual level. The Sichuan snub‐nosed monkey (Rhinopithecus roxellana) is an endangered seasonal breeding species living in a multilevel society. From Sep 2007 to May 2008 we recorded 290 inter‐group conflicts of a free‐ranging provisioned band of R. roxellana in the Qinling Mountains of China to investigate the function of individual aggression during inter‐group encounters. Our findings show that adult males were the main participants in inter‐group conflicts, while females took part in them only occasionally. The male participation rate during the mating season, when adult females were estrous, was significantly higher than that during the non‐mating season. Furthermore, males directed their aggression to other males, and directed more intense aggression towards bachelor males than towards other resident males. For both sexes, the participation rate as initiators was higher in the winter than that in the spring; and there was a significant positive correlation between group size and the participation rate as initiators. Our results suggest that inter‐group aggression in Sichuan snub‐nosed monkeys is linked to both mate defense and resource defense.  相似文献   

5.
The results of a questionnaire provided data about owners' perceptions of the cause of death of over 3000 British dogs. The mean age at death (all breeds, all causes) was 11 years one month, but in dogs dying of natural causes it was 12 years eight months. Only 8 per cent of dogs lived beyond 15, and 64 per cent of dogs died of disease or were euthanased as a result of disease. Nearly 16 per cent of deaths were attributed to cancer, twice as many as to heart disease. Neutered females lived longer than males or intact females, but among dogs dying of natural causes entire females lived slightly longer. In neutered males the importance of cancer as a cause of death was similar to heart disease. Mongrels lived longer than average but several breeds lived longer than mongrels, for example, Jack Russells, miniature poodles and whippets. There was no correlation between longevity and cardiovascular parameters (heart rate, systolic, diastolic, pulse and mean arterial pressure, or the combination of heart rate and pulse pressure) but smaller dogs had longer lifespans. The results also include breed differences in lifespan, susceptibility to cancer, road accidents and behavioural problems as a cause of euthanasia.  相似文献   

6.
In order to control rates of response and inbreeding, mate selection using fuzzy selective mating criteria (FMC) was investigated in adult multiple ovulation and embryo transfer nucleus schemes for dairy cattle. Stochastic simulation was used to model the closed nucleus scheme. This mate selection was examined in four alternative mating and male selection schemes: (i) a hierarchical scheme; (ii) a hierarchical sibship scheme (two males per sibship); (iii) a factorial scheme (two sires per dam); and (iv) a factorial sibship scheme (two males per sibship and two sires per dam). Genetic response and inbreeding rate tended to be reduced by increasing the trade-off parameter of FMC between the expected breeding value and inbreeding of progeny. Inbreeding rates in all schemes were reduced by reducing the variance of family size through selection and the average coancestry of mating pairs through mate allocation.  相似文献   

7.
The objective of this study was to develop a method to optimize the selection and mating decisions based on genotypic information with overlapping generations by applying mate selection algorithm. In this study, differential evolution algorithm was used to optimize numbers of mating between genotypes and the optimal numbers of males and females selected from each genotype over planning horizon. This method assumed a single biallelic QTL ( Q and q ) and was applied to a simple situation in a herd of pigs as an example. Four dominance degrees of gene: recessive, additive, complete-dominance and over-dominance were considered. For all dominance degrees, the frequency of the favourable allele in males selected for replacement increased rapidly. In contrast, the frequency of favourable allele in females selected for replacement increased more gradually. The superiorities in cumulative discounted performance (CDP) when the initial allele frequency was 0.5 over a case when the frequency was 0.05 over the planning horizon were greatly affected by dominance degrees. The CDP superiorities ranged from 24% for an over-dominant QTL to 91% for a recessive QTL.  相似文献   

8.
Our aim was to compare bucks' homosexual mating behavior after mixing 2 groups of bucks, one that was reared in permanent contact and another in complete isolation from female goats, and determine if this behavior was related with testosterone concentration. Two groups of 1-year-old Saanen bucks were reared in permanent contact with 4 adult females until 1 week before the experiment (n = 8; group RF) or isolated from females (n = 9; group RI). When bucks were 1 year old, both groups were mixed (day 0), and mount attempts and matings were recorded on days 1, 3, 6, and 9. Testosterone concentrations were determined by radioimmnoassay from blood samples collected twice daily on days ?7, 0, 1, 3, 6, and 9. Each RI male attempted to mate more RF than RI males (31.9 ± 5.1% vs. 16.7 ± 3.6%, respectively; P = 0.01), but there was no difference on the frequency in which RF males attempted to mate RI (19.4 ± 0.1%) or RF (11.1 ± 0.1%) males (P = 0.24). Similarly, RI males mated more RF than RI males (12.5 ± 2.9% vs. 5.6 ± 0.02%, respectively; P = 0.04). Furthermore, there was no difference on the frequency in which RF males mated RI (10.7 ± 8.9%) or RF (3.6 ± 0.02%) males (P = 0.23). Testosterone concentrations tended to be greater in RF than RI (P = 0.054), but no interaction between time and group was observed (P = 0.13). We propose that as RI bucks never had contact with females, they directed their sexual behavior toward other males that had the stimulating effect of the novelty. On the other hand, for RF bucks, although the novelty effect of the new bucks existed, the previous knowledge of females determined that other bucks were not considered as highly sexual attractive. This difference was not related to the differences in testosterone concentration.  相似文献   

9.
The aim of this study was to investigate social behavior in preweaning lambs, especially their preferences in social interactions. A total of 30 lambs (16 Polish Milk Sheep 05 and 14 Polish Whiteheaded Mutton Sheep) were observed for 113 h 30 min during the first 2 months of their lives. Interbreed differences were insignificant both in agonistic and affiliative behavior. Males appeared to be more active both in agonistic and affiliative interactions. They also preferred other males in agonistic interactions. On the other hand, females fought more often with males, than with females. Lambs of both breeds preferred individuals of their own breed as partners in affliative behaviors. Twins preferred most their siblings in affliliative interactions and usually did not attack and fight with them. This study shows that sex and breed can influence social preferences in preweaning lambs.  相似文献   

10.
To evaluate the potential of the native Muscovy ducks in Congo, a trial was conducted with closed housing, commercial feeding and veterinary care. The characterization included reproductive performance, daily weight gain, live body weight, feed conversion ratio, body live weight productivity, and meat productivity. The experimental genetic stock was bred under natural mating and natural incubation. The number of eggs recorded per female and per clutch was 14.6 ± 3 eggs with 2 clutches per year. The average (±SD) hatchability was 75% ± 3% and the average egg weight was 72 ± 8 g. The sexual dimorphism for body weight appeared after 3 weeks (p < 0.05). The maximum daily weight gain in males reached 55 ± 8 g/day and occurred at 5 weeks, whereas in females it occurred at 4 weeks and reached 35 ± 5 g/day. The carcass yield was 70% ± 5% and 51 ± 8% in males and females, respectively. The meat productivity was 26.7 and 11.5 kg/m2 per year in males and females, respectively. From these findings, it can be concluded that the incubation by mother duck is preferred in the small farming duck and that males should be raised for meat and females for egg production. Further studies including local poultry-related issues are needed to optimize the performance of the native Muscovy duck in Congo Brazzaville.  相似文献   

11.
Postural origin theory predicts that body postures are related to hand preference in nonhuman primates due to hemispheric specialization. Foot preference, especially in manipulating objects, is also a good predictor of hemispheric specialization in humans. We studied limb (hand and foot) preferences in 11 captive adult black‐and‐white snub‐nosed monkeys (Rhinopithecus bieti) to see how limb preference is influenced by postures and foot manipulation. Hand preference was significantly different for this group between quadrupedal standing and clinging postures, and sitting and clinging postures, but not between bipedal standing and clinging postures. Individuals were significantly more likely to use the right hand in the clinging posture than in quadrupedal standing or sitting postures. In the sitting posture, individuals maintained their respective hand preference even when the food was on the other side of the body. There was a gender difference in the sitting posture, where females preferred their right hand but males preferred their left. Individuals who did not routinely use their feet to manipulate objects, compared to those who did, shifted to greater right hand use from the clinging posture to the bipedal posture. One male individual and his offspring were more likely to use their feet to manipulate objects than the rest of the monkeys. In the present study, we reveal the first evidence of a postural effect on hand preference in R. bieti as well as a foot preference in this species. Our results mostly agree with the postural origin theory and hemispheric specialization.  相似文献   

12.
Establishment of European eel (Anguilla anguilla) hatchery production will rely on selectively bred individuals that produce progeny with the best traits in successive generations. As such, this study used a quantitative genetic breeding design, between four females and nine males (four wild‐caught and five cultured), to investigate the effect of paternal origin (wild‐caught vs. cultured) and quantify the relative importance of parental effects, including genetic compatibility, on early life history (ELH) performance traits (i.e. fertilization success, embryonic survival at 32 hr post‐fertilization, hatch success and larval deformities at 2 days post‐hatch) of European eel. Wild‐caught males had higher (56%) spermatocrit values than cultured males (45%), while fertilization success, embryonic survival, hatch success and larval deformities were not significantly impacted by paternal origin. This demonstrates that short‐term domestication of male eels does not negatively affect offspring quality and enables the consideration of cultured male broodstock in future breeding programmes. Moreover, paternity significantly explained 9.5% of the variability in embryonic survival, providing further evidence that paternal effects need to be taken into consideration in assisted reproduction protocols. Furthermore, maternity significantly explained 54.8% of the variation for fertilization success, 61.7% for embryonic survival, 88.1% for hatching success and 62.8% for larval deformities, validating that maternity is a major factor influencing these “critical” ELH traits. At last, the parental interaction explained 12.8% of the variation for fertilization success, 8.3% for embryonic survival, 4.5% for hatch success and 20.5% for larval deformities. Thus, we conclude that eggs of one female can develop more successfully when crossed with a compatible male, highlighting the importance of mate choice for successful propagation of high‐quality offspring. Together, this knowledge will improve early offspring performance, leading to future breeding programmes for this critically endangered and economically important species.  相似文献   

13.
雌性动情状态和雄性等级对布氏田鼠社会行为的影响   总被引:3,自引:3,他引:0  
张建军  梁虹  施大钊 《草地学报》2006,14(3):280-283
在雄性竞争条件下,不同动情雌性布氏田鼠与雄鼠之间行为观察表明:(1)雌鼠动情状态下,优势雄鼠的攻击、自我修饰行为以及交配频次与交配时间均显著高于从属雄鼠,并具有交配优先权;优先被动情雌性选择交配。而从属雄鼠则表现出更频繁的上跳(逃跑或亢奋)行为。(2)当雌鼠处于非动情状态下,雌鼠与优势雄鼠间的相互嗅问行为频次显著高于雌鼠与从属鼠;优势鼠对雌鼠和从属雄鼠的攻击行为频次均显著高于从属鼠对雌鼠和优势雄鼠的攻击;从属鼠也表现出频繁的上跳行为。(3)在与不同雌鼠动情状态下共栖时,从属雄鼠对动情雌鼠的攻击行为频次显著高于对非动情雌鼠;优势雄鼠和从属雄鼠,与非动情雌鼠的友好行为频次均高于雌鼠;与非动情状态雌鼠共栖,雄鼠之间的友好行为频次显著高于动情雌鼠状态。(4)雌鼠动情状态和雄鼠等级会影响雌雄鼠之间的相互行为,动情雌鼠优先与优势雄鼠交配。  相似文献   

14.
为全面掌握娟姗种公牛在高寒牧区的适应性和生理机能变化情况,将6月龄娟姗种公牛引入牧区后观测生理机能变化情况,待体成熟后与牦牛开展自然交配。对牦牛自然交配和人工授精方式下的繁殖性能进行对比分析,结果表明:自然交配方式下母牦牛受胎率、产犊成活率、繁殖率比采用人工授精技术的母牦牛相应指标分别高19.26%、25.71%和23.12%,流产率和初生犊牛死亡率则比采用人工授精技术的母牦牛分别低8.54和5.64个百分点。同时对两种杂交技术下牦牛所产的后代娟犏雌牛进行犊牛生产性能对比分析,结果表明:自然交配母牦牛所产的后代娟犏雌牛犊比人工授精的母牦牛所产娟犏雌牛犊的初生重、12月龄体重、初胎初乳量、初胎年均泌乳量分别高4.92 kg、21.86 kg、0.36 kg、197.89 kg,两组数据经差异显著性检验,自然交配组的娟犏雌牛犊初生重、12月龄体重、初胎年均泌乳量均极显著的高于人工授精组的相应指标(P<0.01),初胎初乳量差异显著(P<0.05)。  相似文献   

15.
为建立完善的金州黑色标准水貂交配体系,选择性成熟的雌性和雄性金州黑色标准水貂,采用同一雄性的2次交配("1+1"、"1+7"或"1+8")、同一雄性3次交配("1+7+1'或"1+8+1")、不同雄性2次交配("A1+B7"或"A1+B8")和不同雄性3次交配("A1+A7+B1'、"A1+B7+B1"或"A1+B7+...  相似文献   

16.
Reason for performing study: To improve efficiency at the farm level, a better understanding of how farm management factors impact reproductive performance is important. Objective: To assess reproductive efficiency and effectiveness among Thoroughbred mares in central Kentucky. Methods: A cohort of 1011 mares on 13 farms in central Kentucky was followed during the 2004 mating and 2005 foaling season. Information on farm level practices was collected via interviews with farm managers. Reproductive records were collected for each mare mated to obtain information on mare characteristics. The influence of mare age and status (maiden, foaling, barren) on Days 15 and 40 post mating pregnancy rates, foaling rates and total effective length of the mating season were assessed. The influence of stallion book size on reproductive performance measures was also examined. Results: Per season pregnancy rates on Days 15 and 40 post mating and live foal rate were 92.1, 89.3 and 78.3%, respectively. Per cycle rates for the same time periods were 64.0, 58.3 and 50.8%. There were no significant associations between stallion book size and reproductive performance outcomes. The mean s.d. interval from the beginning of the mating season to the last mating of the mare was 36.5 ± 26.1 days. Conclusions: Mare age had a significant impact on efficiency of becoming pregnant, maintaining pregnancy and producing a live foal. Overall, fertility did not decrease among stallions with the largest book sizes. Total interval length of the mating season can be reduced if managers ensure maiden and barren mares are mated at the beginning of the season and foaling mares are mated at the earliest oestrus after acceptable uterine involution has been achieved. Potential relevance: Measures identified in the study can be used by owners, farm managers and veterinarians to improve mare reproductive performance and identify parameters to assist with the implementation of effective culling practices.  相似文献   

17.
陈连忠  陆汉 《蚕业科学》1990,16(3):149-151
天蚕制种技术的关键,是提高天蚕蛾的交尾率.采用盒内交尾、笼内交尾、罩内交尾和自由交尾等方法进行试验调查.结果,以自由交尾为最佳,交尾率达80%以上.  相似文献   

18.
The cost of reproduction is the core driver of life history evolution in animals. This paper demonstrates that the cumulative distance moved and the duration of movement of sexually immature abalones, Haliotis discus hannai, kept in various male and female groups, were significantly higher than those of sexually mature individuals, except when kept in mixed cultures of mature males and females. After mixed-culture, sexually mature males moved significantly further and for a longer duration than mature female abalones, and even more so than mature male abalones of any other group. Examination of the LC-MS metabolomics of mature males cultured with sexually mature females (AM) and those cultured with sexually immature females (JM) showed that cyclic adenosine monophosphate (cAMP) acted as a differential metabolic biomarker. After 24-h uninterrupted sampling, the concentration of 5-HT and the expression levels of the 5-HT2 and 5-HT6 receptors in AM were significantly higher than those in JM. After further injection of 5-HT2 and 5-HT6 receptor antagonists, the concentrations of cAMP and PKA rose again, but the cumulative movement duration and distance of male abalones decreased significantly, showing that 5-HT was involved in the regulation of movement behavior of male abalones through the 5-HT2 and 5-HT6 receptor-activated cAMP-PKA pathways. The results demonstrated a significant increase in the movement endurance of mature male abalones cultured with mature females, providing a theoretical basis for understanding the adaptive life history strategies of abalones and suggesting ways to protect diverse benthic resources for abalones during the reproductive stage.  相似文献   

19.
The aim of the study was to analyze the effects of the first mating date, age and color variety on the conception rates in farm mink. We analyzed female mink reproductive performance in 492 Sapphire and 463 Standard Black females over 3 or 4 years. The analysis included the number of inefficient matings, the interval between the first inefficient mating and the efficient mating (copulation) and the conception rates. The results show a significant effect of female's age and color variety on the conception rates. The youngest, yearling females of either color needed a higher number of matings per conception, as compared to older, 2‐ and 3‐year‐old females. Black females demonstrated a higher number of inefficient matings (1.066), as compared with Sapphires (0.730). Yearling females were most often mated from 1 to 10 March, and older females from 11 to 20 March. Older females achieved better conception rates than the yearlings. Dates between 11 and 25 March proved to be the optimum for the first mating, since the highest conception rates were observed if the females had mated during this period.  相似文献   

20.
S.M. Hirst 《African Zoology》2013,48(2):199-230
Cape sugarbirds (Promerops cafer) are the largest nectarivores in the Western Cape and feed almost exclusively on protea nectar and associated arthropods. Helderberg Nature Reserve, Western Cape, South Africa, has a large diversity of Protea and supports breeding sugarbirds. As part of a larger study, we captured sugarbirds using mist-nets during the breeding and non-breeding season at several sites in the Helderberg Nature Reserve, Western Cape, South Africa, from 1996 to 2000. From these data (n =283 males, 272 females), we found that in both sexes, individuals with longer tails have longer wings. Males were significantly larger in mass, culmen, head, tarsus, wing and tail length than females. Males with larger mass were larger in all morphometric measurements than those with smaller mass. Mate choice and territory defence may be based on wing and tail ornament displays of male sugarbirds, thus larger males with larger ornaments could benefit through greater breeding success than smaller males.  相似文献   

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