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1.
Data on reproductive activity of fossorial species are limited because the specimens are difficult to be observed and captured. Here in, we present the reproductive cycle of female Atractus pantostictus, a fossorial neotropical species, and the sexual maturity of males and females in south‐eastern Brazil. The female reproductive cycle of A. pantostictus is seasonal, with vitellogenic follicles being found from September to April and eggs in November, February, March and April with the number varying between two and four. Spermatozoa were found in the lumen of the glandular and non‐glandular uterus in females collected during the rainy season. Sperm storage tubules were found in the posterior infundibulum of the females, where the storage of sperm occurs for a short time. The storage may occur because mating and ovulation are dissociated.  相似文献   

2.
Testes of 15 wild adult male raccoon dogs (Nyctereutes procynoides) obtained from September 2000 to April 2001 were studied to clarify seasonal changes in spermatogenesis and testicular steroidogenesis. There were marked seasonal variations in the testis weight and size with values relatively low in September and highest in March. Spermatogonia and primary spermatocytes were observed in September, while spermatogonia, spermatocytes and round spermatids were present in January, and all types of spermatogenic cells including mature spermatozoa were found in the mating season (February and March). The number of spermatogenic cells reached their peak values in February and March. In addition, steroidogenic enzymes were immunolocalized using polyclonal antisera raised against bovine adrenal cholesterol side-chain cleavage cytochrome P450 (P450scc), human placental 3beta-hydroxysteroid dehydrogenase (3 betaHSD), porcine testicular 17alpha-hydroxylase cytochrome P450 (P450c17), and human placental aromatase cytochrome P450 (P450arom). P450scc and P450c17 were identified in Leydig cells and spermatids in February, whereas these enzymes were present only in Leydig cells in September. 3betaHSD was found in Leydig cells in September and February with more intense staining in February. The localization of P450arom changed seasonally: no immunostaining in September; more extensive immunostaining in Leydig cells, Sertoli cells, and elongating spermatids in February. These results suggest that seasonal changes in the testis weight and size of wild male raccoon dogs are correlated with changes in spermatogenesis. Seasonal changes in testicular steroidogenesis suggest that the synthesis of androgen and estrogen reaches its peak in the mating season.  相似文献   

3.
A total of 89 Thoroughbreds, 14 to 333 days old (born in 1982), were examined at necropsy for certain internal parasites during a 1-year-period, Mar 1, 1982, to Feb 28, 1983. The eyes of 73 of the horses and the cranial mesenteric arteries of 71 were examined. Specific interest was on prevalence of parasites according to month of the year and age of the horses at necropsy. Parasites recovered (first month-last month infected horse found) were as follows: Thelazia lacrymalis (eyes) immature and mature (June - February); Habronema/Draschia (lungs) immature (May - September); Habronema muscae (stomach) immature (July - February) and mature (September - February); Draschia megastoma (stomach) immature (August - December), mature (August - February), and lesions (September - February); Gasterophilus intestinalis (stomach) 2nd instars (July - February) and 3rd instars (August - February); Gasterophilus nasalis (stomach) 2nd instars (August - November) and 3rd instars (August - February); Parascaris equorum (lungs) immature (March - November), P equorum (small intestine) immature (March - February), and mature (July - February); Strongyloides westeri (small intestine) mature (March - September); Anoplocephala perfoliata (cecum) immature and mature (August - February); Strongylus vulgaris (cranial mesenteric artery) immature and mature (May - February). Other parasites recovered, but only from 1 or 2 horses each (months found in infected horses) were: Thelazia skrjabini (eyes) (October), Dictyocaulus arnfieldi (lungs) (January); Trichostrongylus axei (stomach) (October); Anoplocephala magna (small intestine) (October, November); S vulgaris (cecum) (November); Strongylus edentatus (cecum) (January); Setaria spp (abdominal cavity) (January). Influence of probable chemotherapy of the horses on prevalence of the parasites is discussed.  相似文献   

4.
The aim of the study was to evaluate the use of laparoscopy for the assessment of the reproductive tract and stage of gonadal development of the tench (Tinca tinca). Laparoscopy was carried out from February to March 2009, on 30 anesthetized tenchs, 15 males and 15 females, of approximately 250 g bodyweight and 30 cm length, using a 1.9‐mm rigid cystoscope. Male and female gonads, attached to the swim bladder, were visualized. Testes were orange with a striped appearance. Mature ovaries were cluster‐shaped and whitish. Histological samples were collected, from the reproductive organs of both the sexes, with a forceps and showed the presence of gametes at different stages of maturity. The application of this minimally invasive diagnostic imaging technique could clinically be used as a powerful tool to evaluate the gender and to establish the reproductive status of tench and other fish.  相似文献   

5.
利用屠宰场屠宰的沼泽型水牛卵巢采集卵母细胞,统计了一年中4个季度1—3、4—6、7—9、10—12月份每个卵巢平均获卵母细胞总数、可用卵母细胞数及不可用卵母细胞数。结果：每个卵巢平均获卵母细胞总数分别为4.06枚±0.63枚、4.62枚±0.75枚、4.50枚±1.06枚、3.87枚±1.34枚,其中可用卵母细胞数分别为1.70枚±0.57枚、1.86枚±0.55枚、2.06枚±0.63枚和1.67枚±0.50枚;4个季度卵母细胞成熟率分别为：（81.5±6.2）%、（70.7±5.6）%、（70.7±9.3）%和（77.0±6.9）%。以上结果表明,在每个卵巢平均获卵母细胞总数上,4—6月份、7—9月份两季度显著高于10—12月份（P〈0.05）,其他季节间没有显著性差异（P〉0.05）;7—9月份每个卵巢平均获可用卵母细胞数最高,显著高于1—3月份和10—12月份（P〈0.05）,但与4—6月份之间没有显著性差异（P〉0.05）;4个季度不可用卵母细胞数之间没有差异（P〉0.05）;4个季度卵母细胞的体外成熟能力上也没有显著差异（P〉0.05）。  相似文献   

6.
We described the reproductive performance of native pigs raised by smallholders in a traditional way and used for ritual sacrifice in a Hmong village in the hills of northern Thailand. Field study was conducted between May 2005 and January 2007 (13 months in total). The pig reproductive performance in ten households during two years (January 2005 to December 2006) was as follows: The 15 farrowing samples in the households had an average litter size at birth of 7.1 and litter size at weaning of 6.0 (pre-weaning mortality 16%). A total of 107 piglets were born in the ten households during the two years, an average of 5.4 piglets per household per year. We were only able to collect data on farrowing intervals in three cases, two of eight months and one of 19 months. There was no concentrated farrowing period: of the 15 farrowings, there were seven months with one farrowing each (February, April, May, June, July, September, November), four with two farrowings (January, March, August, December), and one with none (October). This indicates that households have a variety of attitudes to pig reproduction, and that there is no seasonality in farrowing.  相似文献   

7.
At monthly intervals from February 1983 to January 1984 two Angora goats, two Boer goats, one grysbok, Raphicerus melanotis, one common duiker, Sylvicapra grimmia, one greater kudu, Tragelaphus strepsiceros, and four scrub hares, Lepus saxatilis, were killed on a farm in Valley Bushveld in the Eastern Cape Province, South Africa and examined for ticks. Seven ixodid tick species were collected, of which Rhipicephalus glabroscutatum followed by Amblyomma hebraeum and Rhipicephalus oculatus were the most numerous. Amblyomma hebraeum was mainly a parasite of the two goat breeds, with the Angora goats harbouring greater numbers than the Boer goats, while large numbers of R. glabroscutatum parasitized the goats and the antelopes. Rhipicephalus oculatus was nearly exclusively a parasite of scrub hares. The larvae of A. hebraeum were most numerous on goats from May to July, the nymphs from September to November and the adults from August to December and during February, while the immature stages of R. glabroscutatum were most numerous on these animals from April to July and the adults from August to December. Peak activity periods of the latter tick were somewhat longer on kudus than on goats; the immature stages were most numerous from January to August and the adults from July to February. The larvae of R. oculatus were most numerous on scrub hares from March to May, nymphs from September to November and adults from October to December.  相似文献   

8.
This study aimed to characterize the annual reproductive cycle of Santa Inês sheep in the Fluminense lowland region (latitude 22° 27′ 45″ south, Rio de Janeiro, Brazil) between September 2011 and August 2012. Ten ewes were maintained in a semi-intensive system under natural photoperiods with access to pasture and shelter. Blood samples were collected every 2 weeks to determine plasma progesterone concentrations. The body condition score (BCS) was determined each month. There was no seasonal variation in the plasma progesterone concentration from the months of September to January, April, and May to August. In the months of February and April, the plasma hormone levels were higher than August to November. Seventy percent (7/10) of the sheep studied had short seasonal anestrus. The periods of anestrus were concentrated between the months of September and December (spring season) in 85.7 % (6/7) of the cases evaluated. In these cases, 57.1 % (4/7) also had short periods of reproductive inactivity during other months of the year. The progesterone values obtained in the spring corroborate the higher reproductive anestrus observed in this season. Higher plasma progesterone values were found in summer and autumn with reduction in the winter to lower values in the spring. No changes in the BCS during the study period were observed. Under the studied conditions, the Santa Inês sheep showed a low degree of reproductive seasonality. However, some individual ewes had seasonal anestrus during the spring. Further studies that include management techniques are needed to improve reproductive efficiency without hormone therapy in this breed under tropical conditions.  相似文献   

9.
Ixodid ticks were collected at weekly intervals from February 1999 to April 2000 from domestic dogs belonging to people in rural communities in north-eastern KwaZulu-Natal. Seven ticks were identified to species level and adult Haemaphysalis leachi followed by immature Amblyomma hebraeum and adult Rhipicephalus simus were the most prevalent. Infestation with adult H. leachi was most intense during February and March 1999 and from January to April 2000, and least intense during October 1999. Infestation with adult R. simus was most intense during February and March 1999 and least during July and September of the same year. For 12 consecutive years, from August 1988 to July 2000, free-living ticks were collected at monthly intervals from the vegetation of two landscape zones in the Kruger National Park. Most adult H. leachi were collected in the one zone from March to June, and no ticks were collected in October, whereas, with the exception of March, most were collected in the other zone during the period January to June, and only one tick was collected in October. Most adult R. simus were collected during February and March at both localities and only a single tick was collected in September. Adult Rhipicephalus turanicus was present only in the one zone and was collected only from January to June.  相似文献   

10.
To investigate the influence of daylength on the seasonal reproductive cycle of stallions, 21 stallions were assigned to one of three treatments: control, ambient (natural) photoperiod; S-L, 8 h light and 16 h dark (8:16) for 20 wk beginning July 16, 1982 then 16:8 from December 2, 1982 until March 5, 1984; S-S, 8:16 from July 16, 1982 until March 1984. Temperature was not controlled and was similar for all groups. Total scrotal width (TSW) was measured every 4 wk throughout the experiment. During 10 periods, semen was collected and evaluated every other day for 3 wk and sexual behavior was assessed. The S-L stallions exposed to 16 h light in December had twice as much sperm output in February than in November. Within the February collection period, the sperm output for S-L stallions was greater (P less than .05) than that for either control of S-S stallions. The stimulatory effect of the S-L photoperiod also resulted in larger (P less than .05) testes and decreased (P less than .05) time to ejaculation for S-L stallions in February as compared with either controls or S-S stallions. Despite continued exposure to a 16:8 photoperiod, TSW and sperm output for S-L stallions eventually declined; presumably a consequence of photorefractoriness. The S-S stallions had seasonal cycles coincident with those for control stallions. Based on a sine wave model for TSW and sperm output, stallions in all three groups displayed significant seasonal cycles.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

11.
The reproductive biology of the southern mullet from Algoa Bay was studied between June 1978 and October 1980. Gonadosomatic indices and macroscopic and microscopic examinations of the gonads were used to establish the breeding cycle. The period of greatest sexual development extends from September to March and spawning occurred throughout that period. Spawning probably occurs close in shore. Liza richardsoni exhibited the phenomenon of group synchronism, two distinct oocyte groups being present within a pre-spawning ovary. The proportion of yolkless oocytes exceeded that of vitellogenic oocytes in ripe fish. However, it was not apparent whether all the vitellogenic oocytes would reach maturity. This highlights the need for quantitative histological studies to accompany fecundity estimates. Histological investigations were useful in the clarification of breeding cycle determinations based on gonadosomatic indices and visual macroscopic assessments.  相似文献   

12.
Sentinel chickens were established in 3 centres along the Murray Valley on 20 December 1973. The demonstration of antibody in the serum of chickens in the Mildura and Kerang areas indicated Sindbis virus activity late in December 1973 and early in January 1974. Tests for antibody to MVE virus were negative until blood collected from one chicken at Echuca on 27 February 1974 and several chickens at Mildura and Kerang on 14 March 1974, showed positive HI reactions. Murray Valley encephalitis virus was isolated from blood collected from chickens at Echuca and Kerang respectively on 31 January 1974 and 27 February 1974.  相似文献   

13.
Sixty yaks were autopsied to determine the migration pattern of warble fly larvae. In August, first instars were observed in the body of yak for the first time. These larvae peaked in number in October. From November to February, second instars were detected and their number peaked in January. Third instars appeared in January and peaked in March. Forty-five yaks were administered with ivermectin: 15 animals in September, 15 in October and 15 in November. Between December and June, the number of warbles was checked by palpation. Although some warbles were observed in the September- and November-treated groups, no warbles were detected in the October-treated group. Treatment of yaks with ivermectin was most effective for warble fly in October.  相似文献   

14.
Monthly variations in the magnitude of adult and larval cyathostome burdens were observed in 55 horses necropsied over a 15-month period in the northern USA. Peak numbers of adult cyathostomes occurred in late winter (March) and late summer (September). Larval cyathostomes demonstrated peak numbers from February to April and again in October, beginning one month earlier than the spring adult peak and one month after the autumn adult peak, respectively. The reproductive status of individual female Cyathostomum catinatum, Cyath coronatum, Cylicocyclus nassatus, Cylicostephanus goldi and Cylicostephanus longibursatus was classified as immature, gravid or spent. Seasonal changes in these classifications were monitored as a marker for the age structure of these populations. Each reproductive category of female small strongyle was dominant during only one period per year and these periods were similarly distributed for all five species examined. Immature cyathostomes were most common from late winter to spring (March to May); gravid worms were predominant beginning in spring (April/May) and continuing into autumn (October to December). Spent females prevailed from autumn through winter (October to March/April).  相似文献   

15.
The seasonal occurrence of Pomatomus saltatrix and Lichia amia juveniles in a permanently open (Knysna) and a periodically open (Swartvlei) estuary is described. P. saltatrix was caught only in Knysna from September to April. L. amia was found in both systems intermittently throughout the year. Small juveniles were most abundant from November to February in Knysna and from December to February in Swartvlei. Prey selected varies with size and species although there is some overlap. Behavioural and morphological differences are discussed in relation to prey selection.  相似文献   

16.
Hard ticks (Acari: Ixodidae) were collected from the vegetation at monthly intervals in 2008 on six places of three different biotopes in Hungary. Except for Haemaphysalis concinna and H. punctata, predominance of females was observed in the questing population. From among the species with biphasic activity period, metastriate ticks (Dermacentor spp. and H. inermis) had higher prevalence of host-seeking males in the autumn than in the spring, as opposed to prostriate Ixodes ricinus. In comparison with the permanently mild weather experienced at the beginning of 2007, sharply rising temperatures during consecutive winter days in January and February of 2008 appeared to be more efficient in triggering a 1–2 month earlier spring peak activity of hard ticks, except for I. ricinus. Regarding seasonality, D. marginatus was most numerous in February and March, whereas D. reticulatus in September and October; H. punctata showed peak activity in March–April, H. concinna in May, and H. inermis in November–December. Within these genera such a temporal difference (allochrony) between seasonal peak activities of sympatric species under continental climate is described for the first time.  相似文献   

17.
An understanding of seasonal dynamics in the free-living phase of the tropical horse tick, Anocentor nitens, is vital for effective control measures. This study examines seasonal changes in the oviposition and incubation periods, eclosion rates, reproductive success, and larval survival in the free-living phase during the period June 1995-July 1997. Ten engorged female ticks, placed individually in wire-gauze tubes, were exposed in a field of Brachiaria decumbens fortnightly each month, and monitored to measure the duration of the various reproductive parameters, and success. Larval abundance was estimated indirectly, through the percentage of females with viable progeny, and directly by using a flagging method. Duration of the free-living cycle ranged from 12.3 weeks (October and December) to 23.5 weeks (March). The cycle was prolonged in cold and dry months. Larval survival was longer from February to July, and reduced from August to February. Oviposition was recorded in all months, and the egg production index ranged from 26.7 to 47.1%. The eclosion rate ranged from 0.1 to 76.6% in different months. Monthly estimates of larval abundance in the pasture were similar for the two methods used, being higher in months with higher temperatures, relative humidity and rainfall.  相似文献   

18.
高寒草地生物量及牧草养分含量年度动态研究   总被引：2，自引：0，他引：2  
测定了西藏那曲地区高寒草地1~12月份围栏内和围栏外的地上生物量(BM)及牧草粗蛋白质(CP)、粗脂肪(EE)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)和灰分(Ash)含量。结果表明:围栏内年平均BM极显著高于围栏外(15.02 DM g/m2对11.70 DM g/m2,P<0.01),而围栏内外牧草各种养分含量差异不显著(P>0.05)。不同季节BM和牧草养分含量变异较大,BM呈“单峰”曲线变化趋势,8月份最高(33.02 DM g/m2),3月份最低(6.39DM g/m2);牧草CP、EE含量亦呈“单峰”曲线变化趋势,CP含量在8月份达到最高(10.68%DM),在2月份降到最低(2.72%DM),EE含量变异不大,在9月份较高(3.77%DM),1月份较低(2.26%DM);NDF变化规律与CP相反,呈“V”型曲线变化趋势,最低和最高含量分别在8月份(49.38%DM)和12月份(69.08%DM);ADF含量全年变化不大,夏季较(35.03%DM)冬春季低(42.92%DM);Ash在6月份含量最高(18.29%DM),2月份含量最低(7.14%DM)。以月份为自变量,进行适当变换后建立了牧草生物量和养分含量的全年动态变化回归模型。  相似文献   

19.
Two experiments were performed to assess the role of refractoriness to long and short daylengths in the timing of seasonal reproductive transitions in Mediterranean Malagueña goats. In the first experiment, intact adult does were either maintained under natural photoperiod conditions (NP; n = 5) or exposed to a constant long day photoperiod (LD – 16 h light/day; n = 5) from June to December 2005. In the second experiment, does were maintained either under NP conditions (n = 5) or received a series of subcutaneous melatonin implants (MI) from December 2005 to June 2006 to mimic a short day signal (n = 5). In both experiments, ovulatory activity was assayed by determining progesterone concentrations in blood samples collected twice per week. The onset of seasonal ovulatory activity did not differ (p > 0.05) between the LD and NP does (3 October ±5 days and 23 September ±3 days respectively). The simulated short days did not modify (p > 0.05) the timing of the end of ovulatory activity. The MI does become anoestrus at the same time (1 March ±9 days) as their NP counterparts (23 February ±8 days). These results indicate that, in Malagueña does, the onset and offset of anoestrus are not driven by photoperiod changes but appear to be the result of long and short day refractoriness respectively. An endogenous circannual rhythm may therefore be involved in regulating seasonal reproductive changes in these animals.  相似文献   

20.
Reproductive traits and calving weight were assessed in Saudi camels, and non-genetic factors influencing them were studied using data collected at Al Jouf centre from 1987 to 2009. Age at first conception, age at first calving, open period, calving interval, gestation length and weight at calving of camels averaged 42.3 months, 54.8 months, 10.6 months, 22.6 months, 377.5 days and 591.9 kg, respectively. A mixed model including the camel as a random effect was used to assess the effect of environmental effects on the traits studied. Age at first conception and age at first calving were affected by camel’s birth year. Open period and calving interval were not affected by parity or year of calving. However, camels that calved from October to February had a calving interval of 2.5 months higher than those that calved from March to September. Gestation length was affected by season and year of calving but not by parity or sex of calf. Camels calving from March to September had a gestation length 6.6 days shorter than those calving from October to February. Weight at calving was affected by parity and year of calving but not by season of calving. It was concluded that an improvement in camel reproductive traits is possible both through improving management systems and utilisation of controlled breeding techniques.  相似文献   

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