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1.
The optimal time for mating bitches was determined by measuring the progesterone concentration in peripheral blood three times a week after the start of vulval bleeding. Of 104 bitches with reduced fertility 81 (78 per cent) became pregnant and of 112 bitches with normal fertility 105 (94 per cent) became pregnant. Of 121 bitches mated once, 102 (84 per cent) became pregnant, and of 95 bitches mated more than once, 84 (88 per cent) became pregnant. The mean (+/- sd) interval between the start of vulval bleeding and the optimal time for mating in 88 bitches was 11.8 +/- 3.1 days. The blood progesterone concentration appears to be an excellent indicator of the best time for mating, particularly in bitches with reduced fertility.  相似文献   

2.
The administration of melatonin via intravaginal sponges is an effective method of advancing the breeding season in ewes. In the present study the fertility of melatonin-treated ewes has been compared with that of ewes induced to ovulate by conventional treatment. On June 25, 15, 15-month-old ewes (group 1) were given intravaginal implants containing melatonin in silastic tubing. On August 8, 13 similar ewes (group 2) were given Veramix sponges which were removed 12 days later, when they were given 500 iu pregnant mare's serum gonadotrophin (PMSG). Two intact raddled rams were introduced to the combined groups on August 21. The mean date of mating was September 3 +/- 1.5 for group 1 and August 21 +/- 0.2 for group 2 ewes. All the ewes in group 1 and 10 in group 2 (77 per cent) were mated. All the ewes were slaughtered approximately 50 days after mating and their reproductive tracts removed. The mean ovulation rates were 2.1 and 2.3 in groups 1 and 2, respectively. The results indicate that conception rates of 87 per cent and 61.5 per cent of ewes put to the ram were obtained in the melatonin-treated and PMSG-treated groups, respectively. At slaughter the melatonin-treated group were found to have a mean of 1.47 live fetuses per ewe put to the ram and the PMSG-treated group a mean of 1.08. It can therefore be concluded that melatonin implantation is an effective method for the advancement of seasonal breeding in anoestrous sheep, and that the fertility achieved is at least as good as that given by conventional progestogen-PMSG treatment.  相似文献   

3.
The fertility of 646 ewes and gimmers bred by laparoscopic artificial insemination (LAI) in the autumn of 2006 was investigated using a questionnaire and individual ewe breeding records kept for 13 commercial sheep flocks that used LAI routinely. Overall, the pregnancy rate was 66 per cent, but it was highest in ewes bred for the fourth time. Technical aspects of LAI influenced fertility: pregnancy rates were 70 per cent for ewes bred using frozen semen compared with 58 per cent when fresh semen was used (P≤0.01), and 74 per cent of ewes that travelled to an artificial insemination centre for mating conceived, compared with 62 per cent that remained on their own farm (P<0.01). Higher doses of equine chorionic gonadotrophin (>400 iu) used for oestrus synchronisation reduced pregnancy rates to only 49 per cent (P<0.001). However, the largest effect was associated with shepherds gathering, handling and treating breeding ewes four to six weeks before mating; pregnancy rates were 54 per cent among ewes where this was carried out, compared with 74 per cent for ewes not treated in this way (P<0.01).  相似文献   

4.
Two artificial lighting regimens were studied in a commercial unit of 800 sows. The aim was to develop a simplified lighting regimen to overdrive the effects of season on reproduction. A long-day group had a constant 16 hours light and eight hours dark photoperiod in all units during a production cycle. A short-day group had eight hours of light and 16 hours darkness in a farrowing unit for four weeks and in a mating unit for four weeks. After one month of pregnancy the short-day group was transferred to 16 hours light and eight hours dark for the rest of the dry-sow period. Production data were collected for eight months, and the farrowing rate, weaning to oestrus interval, culling rate for fertility problems and the number of live-born piglets were analysed. Seasonal infertility, which had previously affected the herd, was not detected in either group during the follow-up period. The farrowing rate was 90 per cent for both groups. The median weaning to oestrus interval was five days in both lighting regimens with ranges from four to 74 days in the short-day group and three to 55 days in the long-day group. The long-day programme had a positive effect on the weaning to oestrus interval. When the sows were classified as either "normal", with a weaning to oestrus interval of up to 10 days, or "problem" animals, with a weaning to oestrus interval of over 10 days, the short-day programme also had a positive effect. The culling rate for fertility problems was 2.4 per cent for the short-day group and 3.2 per cent for the long-day group (P=0.027). The only significant predictor for the number of live-born piglets was parity (P=0.027).  相似文献   

5.
The concentrations of plasma ceruloplasmin, plasma fibrinogen, serum haptoglobin and the major cell types in blood together with liveweight changes were monitored during the acute phase response in sheep. Five control sheep, five sheep that underwent sham bronchial obstruction, and five sheep that developed pneumonia after bronchial obstruction were examined. Blood samples were taken and liveweights were recorded from four to six days before until 14 days after the surgical operations (sham and bronchial obstruction). The operations led to an acute phase response in the sheep and the development of pneumonia increased and sustained the response or led to a secondary response. Statistically significant changes observed in the blood of the sheep during the acute phase response included increased concentrations of plasma ceruloplasmin and plasma fibrinogen, depression of erythrocyte numbers and elevation of neutrophil numbers (means on day of maximum change as percentage of pretreatment values; 250 per cent, 400 per cent, 80 per cent and 200 per cent, respectively). Serum haptoglobin showed a pronounced and significant increase in concentration (over 6000 per cent of pretreatment values in some sheep). All three groups of sheep showed significant depression of liveweight after overnight confinement in the surgery but this was sustained for the period of the experiment only in the bronchial obstruction group. The results indicated that measurement of the concentrations of the three plasma proteins may be more useful in the diagnosis of tissue injury and infectious disease than the number of circulating neutrophils in sheep.  相似文献   

6.
An ultrasonic linear array scanner with a transrectal probe was used to observe ovarian and uterine changes associated with the reproductive cycle in llamas. 'Waves' of follicular development and regression occurred in unstimulated females, during which the dominant follicle reached a maximum size of 9 to 13 mm; both ovaries were equally active. Ovulation was induced by mating in 80 per cent of cases, and when mating was accompanied by the administration of human chorionic gonadotrophin the ovulation rate increased to 90 per cent and the time to ovulation decreased from two to three days to one to two days. Some spontaneous ovulations occurred. Corpora lutea reached a maximum size of 12 mm (non-pregnant) or 14 mm (pregnant) after seven or 16 days, respectively. The lifespan of the corpus luteum was approximately 11 days in non-pregnant llamas and the regression time was advanced by the administration of prostaglandin or embryo recovery. Pregnancy could be diagnosed as early as 19 days after mating.  相似文献   

7.
This study aims at determining both the accuracy and the rate of heat detection together with the so-called post-insemination anoestrus incidence in four Moroccan dairy herds under natural or semi-hand mating insemination. 369 females (cows and heifers) were involved from 4 large dairy units in which a herd fertility survey took place on a weekly basis. Heat detection was performed several times a day by the herdsman. Blood was sampled for plasma progesterone (P) determination on the oestrus and the mating day, on day 12 later as well as on day 21 after mating. Accuracy (A) was defined as the ratio of correct oestrus on detected oestrus during the mating days. Heat detection rate (R) was defined as the ratio of oestrus detected on oestrus expected, according to the P values 21 days after mating when the females were confirmed to be cycling. Post-insemination incidence was the complementary ratio to the latter. In the Moroccan dairy unit conditions, A = 91 p. 100, and R = 49 p. 100, the post-insemination anoestrus incidence was therefore just over 50 per cent. The distribution of the non-in-heat but mated females (9 per cent) allows two roughly equal sub-populations to be distinguished: those mated in mid-luteal phase and those with a 1-2 day overlap between the follicular phase and the oestrus. Finally the high incidence of post-insemination anoestrus demonstrates the inadequacy of heat detection for pregnancy diagnosis even under natural or semi-hand mating conditions.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

8.
The purpose of this study was to determine whether fertilisation of Bobwhite quail could be secured by artificial insemination. After this proved to be feasible, the period between insemination and the onset of laying fertile eggs, the time during which fertile eggs were laid and levels of fertility and hatchability of eggs obtained from hens inseminated at weekly intervals over an extended period of time were determined.

Semen was collected from Bobwhite quail males by simultaneously applying pressure to both the left and right sides of the vent without prior stimulation. Upon collection, the semen was diluted with 0.9 per cent saline solution to prevent dehydration. Semen volume measurements were made with a tuberculin syringe to which was attached a piece of graduated, fine‐bore plastic tubing. Females were artificially inseminated by placing the diluted semen in the posterior opening of the everted oviduct.

Mean duration of fertility of the eggs from six trials, two of which utilised only a single insemination, one of which was the final insemination of a series of weekly inseminations and three of which utilised two inseminations within a period of 24 hr, was 9.3 days. Percentage fertility of eggs improved considerably after the first trial probably due to improvement of technique and gain in experience. Average fertility of eggs for the six trials was 64–9 per cent.

The average time interval between insemination and the appearance of the first fertile egg was 3.4 days. Peak fertility was reached by the fourth day following insemination.

Fertility of eggs averaged 62.2 ±3.5 per cent and their hatchability averaged 77.2 ±1.4 per cent over a period of 31 weekly inseminations. These values were comparable to 60.2 per cent fertility and 78.9 per cent hatchability which were obtained from natural matings.  相似文献   


9.
Suisynchron was applied to 2,258 gilts, including 850 from breeding farms. Forty-four pigs were checked to elucidate the influence of sexual maturity on the success of oestrus synchronisation. Suisynchron-Pr?mix was fed to the animals over 20 days, the daily dose for each pig having been 5 g. Twenty-four hours were allowed to elapse from the last administration before 1,500 I.U. PMSG were injected. Synchronised oestrus occurred in 81.2 per cent of all pigs between four and six days from serum injection.Fertilisation in response to first insemination was recorded from 72.9 percent of the pigs, their fertility rate being 9.7 piglets from each farrowing sow. The results of oestrus synchronisation obtained from fattening pigs were somewhat inferior to those recorded from pigs of breeding units. Suisynchron and serum of pregnant mares can synchronise oestrus in 91 per cent of all mateable sows with no previous cycle. The fertility rates recorded from such pigs did not exceed 59 per cent or were between 28.9 and 31.9 per cent lower than those recordable from pigs with a cycle history prior to the use of Suisynchron.  相似文献   

10.
Acute phase protein concentrations in blood, food intake and liveweight changes were compared in 10 sheep given intrathoracic injections of yeast and 10 control sheep over a period of 61 days. The yeast injections caused acute pleuritis and limited necrotising lung lesions which progressed to fibrous pleural adhesions and walled-off abscesses. The responses of ceruloplasmin, fibrinogen and haptoglobin were closely correlated (r = 0·87 to 0·91) in the yeast-injected sheep with peaks on days 5 or 7 after treatment (4, 4·6 and over 130 times control, respectively). Albumin concentration fell to a nadir of 89 per cent of control on day 12 after treatment. Depression of food intake was temporally related to the ‘positive’ acute phase protein responses with a nadir on day 5 after treatment (30 per cent of control). Liveweight showed a pronounced fall to five days after treatment and thereafter remained depressed relative to the controls for most of the experimental period. The data suggest that the ‘positive’ acute phase proteins may be useful indicators of production losses due to inflammatory diseases in sheep.  相似文献   

11.
A flock of 294 Swaledale sheep was injected with brain tissue from different sources so as to include strains of natural scrapie currently affecting the Swaledale breed. Discounting intercurrent deaths, 85 per cent of the flock developed clinical scrapie within an observation period of 2557 days (seven years). Scrapie cases fell into distinct early and late groups, occurring at (mean +/- sem) 287 +/- 7 days and 1207 +/- 38 days after injection, respectively. Breeding groups were formed from the survivors after the early cases had occurred and successive lamb crops were produced. Two groups of progeny and two groups of controls were injected with scrapie. The incidence of scrapie in the progeny (27 per cent) was much lower than in the controls (64 per cent). The incidence in the progeny was also assessed in relation to the response of their parents: it was high (about 40 per cent) when one or both parents developed late scrapie but otherwise very low (about 5 per cent). Hence the progeny of surviving parents had a greatly reduced susceptibility to the strains of scrapie used. Seventy-two of these selected progeny formed a nucleus flock which is being bred at Redesdale. The next stage of the experiment is to assess the effect of selected rams in recorded flocks with a high incidence of natural scrapie.  相似文献   

12.
Three sheep, three goats and three cattle were dosed orally with 5.0, 7.5 and 10 mg albendazole kg-1 bodyweight, respectively. Blood samples were taken at intervals for 48 hours after administration. The enantiomeric ratio of the metabolite albendazole sulphoxide (SO.ABZ) was determined by liquid chromatography on chiral stationary phases. At To, the plasma concentration ratio (+)SO.ABZ/(-)SO.ABZ was estimated at 3.0 in sheep, 1.5 in goats and 4.0 in cattle. The proportion of the (+) enantiomer then increased linearly as a function of time during the course of the kinetics. In comparison to the area under the curve for total SO.ABZ, the (+) enantiomer represented 86 per cent in sheep, 80 per cent in goats and 91 per cent in cattle. The specific behaviour of the two enantiomers is probably the result of the enantioselectivity of the flavine adenosine dinucleotide and cytochrome P450 dependent enzymatic systems which are involved in the sulphoxidation and the sulphonation of ABZ.  相似文献   

13.
Twelve cows (mean age 6.4 years) and eight sheep (mean age 0.8 years) were fed silage containing 70 to 90 per cent vitamin D3-effective Trisetum flavescens for a period of 14 weeks. At the beginning and the end of this period, the animals were examined and their kidneys, abdominal aortas and heart valves were examined by ultrasonography; the animals were then slaughtered and these organs were examined histologically, and the specificity and sensitivity of the ultrasonography were calculated. After the feeding period, all the cows had a decreased body temperature and all but one had raised hair, movement disorders and difficulty in rising and lying down. Ultrasonography of the abdominal aorta had a specificity of 90 per cent and a sensitivity of 75 per cent, and ultrasonography of the heart valves had a specificity of 100 per cent and a sensitivity of 50 per cent. In the sheep, cardiac arrythmia was the only pathological finding at the end of the feeding period, and the ultrasonographic examination of the kidneys had a specificity and sensitivity of 100 per cent.  相似文献   

14.
Fecundin, which actively immunises sheep against androstenedione, has now been commercially available to British farmers for three seasons. By its use an average increase of 20 to 25 per cent in the number of lambs reared can be expected, although the results on individual farms have been variable. During 1984-85 and 1985-86 ADAS carried out trials involving over 2000 ewes on 13 commercial farms. The responses to the treatment were statistically significant in both years (+23 per cent in 1984-85 and +27 per cent in 1985-86). However, the ranges in response were from -2 per cent to +49 per cent and +9 per cent to +42 per cent in 1984-85 and 1985-86, respectively. Similar results have been reported by other workers and commercial farmers using the technique. From these data it is clear that there are interactions between the treatment and animal factors including breed, body condition, nutrition, season and management. These factors are discussed with regard to the implications for the use of the product in commercial flocks.  相似文献   

15.
Data relating to 35,389 inseminations carried out in the first three years after inseminators were trained were collected by postal questionnaire from 94 do-it-yourself (DIY) artificial inseminators in the UK. The mean calving rate from 14,528 inseminations they carried out on 92 farms in the first year after they were trained was 59.4 per cent (range 5 to 92 per cent). In the second year the mean calving rate from 11,515 inseminations by 64 inseminators was 62.3 per cent (range 33 to 88 per cent), and in the third year the mean calving rate from 9346 inseminations by 49 inseminators was 64.6 per cent (range 41 to 92 per cent). There was an increase of 5.2 per cent in the mean calving rate over the three years with an overall mean calving rate of 61.5 per cent. Each trainee carried out an average of 376 inseminations (range 20 to 800) during the three years. Thirteen instructors were responsible for the tuition and the average time the trainees spent in an abattoir with access to live cows was 2.88 days, with a range from none to five days. For the trainees who spent up to three days training in an abattoir there was an increase of 5.9 per cent in the calving rate they achieved in their first year for every day they spent training with access to live cows (P < 0.005), but there were no significant effects on the outcome of their inseminations in their second or third years.  相似文献   

16.
The seroprevalence of maedi-visna virus infection in thin potential cull ewes aged over two years in a flock in East Anglia increased from 3.7 per cent in August 1985 to 39.0 per cent in September 1987 and 93.3 per cent in May 1989. This increase coincided with the first appearance of sheep pulmonary adenomatosis in the flock. Four emaciated ewes which were dyspnoeic were necropsied between 1987 and 1989. Maedi and pulmonary adenomatosis were confirmed histologically in one of these ewes and pulmonary adenomatosis was confirmed in the other three.  相似文献   

17.
The purpose of the study was to investigate the fertility level, some factors affecting fertility and problems of infertility in selected Swedish beef herds. The investigation included 31 herds, 19 of which had Herefords, 13 Charolais, 2 Aberdeen Angus and 1 Limousins. The total number of mature females was 703, including 147 feifers of breeding age. Most data were collected at personal visits to the herds. The results are presented in Tables I--XV and Figures 1--2. The service period coincided roughly with the grazing period and lasted usually 4--5 months. Seventyfive per cent of the females calved during the period February-May. The fertility levels were comparatively good. The percentage of pregnancy at rectal examination performed at the end of the service period was 89.5; however the average calving percentage was only 87.5. The highest calving percentages were recorded for Aberdeen Angus and crossbreds. Also the calf crop, it is the number of calves born alive and surviving 24 hours per mature female was the highest for these two groups; 0.91 and 0.90 respectively. The mean interval from calving to conception was 80.3 days in Herefords, 83.4 days in Aberdeen Angus, 85.6 days in crossbreds and 92.3 days in Charolais. The percentage of animals pregnant within 90 days after calving was on an average slightly more than 50 per cent. The interval from calving to conception rose gradually when the interval from calving to expoure to bull exceeded 40 days. Mean percentages of still born calves were 5.9 in cows and 13.7 in heifers. As far as the fertility level is concerned there does not seem to be any disadvantage in keeping the bull together with the females during the calving period. However, in this case the next calvings will occur over an extended period of time. If the intention is to concentrate 50 per cent of the calvings within the period of one month then the females should be exposed to the bull from 41--60 days after calving at the earliest. In case the females were exposed to the bull from 41--60 days after calving and onwards, 95 per cent of the females finally pregnant had conceived at the end of a 3 months service period. Under such conditions a bull may be able to serve two groups of females within the same grazing period. Cows calving during July-September had the lowest pregnancy rate and those calving during October-December the highest at the following service period. The incidence of ovarian cysts was very low. About 1/3 of those buls serving at least 10 females each obtained calving percentages less than or equal to 80. Herds recording low calving percentages had to a great extent used young bulls, 12--15 months of age at the beginning of the service period. Only for two groups of females out of eleven which had been served by young bulls calving percentages greater than 80 were noted. A more efficient control of the fertility of the bulls could markedly improve the fertility of some herds.  相似文献   

18.
Ivermectin at 200 micrograms/kg bodyweight given either as a single subcutaneous injection or as an oral drench failed to eradicate Psoroptes ovis from artificially infested sheep. The oral drench reduced the mite populations by 43 per cent within 24 hours but no further significant decline was recorded over 38 days. The subcutaneous injection reduced the mite populations by 90 per cent after 10 days but live P ovis were present on all the treated animals 84 days after treatment. The efficacy of treatment was less the higher the initial mite burden. The injection had no effect on clinical sheep scab, and the disease continued to progress despite the mite mortality.  相似文献   

19.
Data derived over four years from 434 dairy herds in 1998/99 to 244 in 2001/02 revealed average disposal rates of 22.6 per cent per year, half of which were for poor fertility, mastitis and lameness. The quartile of herds with the lowest disposal rates sold an average of 11.5 per cent annually and the quartile with the highest rates sold 35.5 per cent. Average annual disease rates over the four years were as follows: for assisted calving 7.8 per cent, for digestive disease 1.2 per cent, for ketosis 0.5 per cent, for hypomagnesaemia 0.5 per cent, for hypocalcaemia 5.0 per cent and for injuries 0.8 per cent. The incidence of mastitis increased from 36.0 to 43.3 per cent of cows per year. The incidence of lameness decreased from 23.3 per cent in 1998/99 to 20.7 per cent in 2000/01 but increased to 21.9 per cent in 2001/02. Data received from the same 219 farms during the first three years showed no effective differences from the full set of data for each of the three years. The lowest annual incidences of mastitis and lameness on individual farms were below 7 per cent and 2.5 per cent, respectively. In general, housing cows in cubicles was associated with a greater risk of lameness, and housing them in straw yards with a greater risk of mastitis. However, some of the lowest rates of lameness were recorded in cubicle-housed cows and some of the lowest rates of mastitis were recorded in cows housed in yards. Larger herds were not associated, in general, with higher rates of mastitis.  相似文献   

20.
Reports of clinical scrapie in Great Britain between January 1, 1993 and December 31, 2002 were reviewed. Scrapie was confirmed in 4142 sheep on 1099 holdings. The cumulative case and holding incidence risks decreased in 2001, probably owing to the outbreak of foot-and-mouth disease, although there were regional variations. Sheep aged between three and four years old constituted the largest affected group. In the period between 1998 and 2002, 51.3 per cent of the cases had the genotype ARQ/VRQ, 19.3 per cent were ARQ/ARQ and 18.9 per cent were VRQ/VRQ; Swaledale, Shetland and Welsh mountain sheep were the most common pure breeds reported. The areas at highest risk were the Shetland Islands, followed by the south and east of England.  相似文献   

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