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1.
The purpose of this study was to examine the effect of time for mating and gestation length on reproductive efficiency in dogs. Groups of eight, six and six beagle bitches were mated with a total of three sires on days 3, 5 and 7, respectively, after the luteinizing hormone (LH) surge. All the bitches whelped successfully. The gestation lengths (the intervals from the LH surge to the whelping) were 65.1 +/- 1.9, 65.5 +/- 1.9 and 68.0 +/- 1.8 days, respectively. This length of mating 7 days after the LH surge was significantly longer than that of mating 3 and 5 days after the LH surge (p < 0.05). The litter sizes were 5.5 +/- 2.2, 6.2 +/- 1.9 and 4.8 +/- 2.1, respectively and there was no significant difference between any of the groups. In conclusion, mating 3-7 days after a bitch's LH surge results in a good reproductive efficiency and the intervals from the LH surge to the whelping of mating 7 days after the LH surge shows a longer day significantly in comparison with mating 3 and 5 days after the LH surge.  相似文献   

2.
The present work aimed to determine if different levels of prolificacy either by parity or by genetic origin are linked to folate metabolism. Nulliparous Yorkshire-Landrace (YL) and multiparous YL, and multiparous Meishan-Landrace (ML) sows were randomly assigned to two treatments: 0 ppm or 15 ppm folic acid+0.6% glycine. Supplements were given from the estrus before mating until slaughter on d 25 of gestation. At slaughter, embryo and endometrial tissues were collected to determine concentrations of DNA, protein, and homocysteine. Allantoic fluid samples were also collected to determine concentrations of folates, vitamin B12 and amino acids. Blood samples were taken at first estrus, at mating, and on d 8, 16, and 25 of gestation to determine serum concentrations of folates, vitamin B12, and relative total folate binding capacity (TFBC). Over the entire experiment, multiparous YL sows had higher average serum concentrations of folates than nulliparous YL sows (P < 0.05) but had similar serum concentrations of relative TFBC. Concentrations of folates and relative TFBC averaged higher in ML measured over the entire experiment than in multiparous YL sows (P < 0.05). Concentrations of serum vitamin B12 were higher in multiparous YL than in ML sows or YL nulliparous sows (P < 0.05) over the entire experiment. In allantoic fluid, folates, vitamin B12, and essential amino acids contents were significantly lower in ML than in YL multiparous sows (P < 0.05). The folic acid+glycine supplement increased concentrations of serum folates, but the increase was more marked in nulliparous YL sows (nulliparous x folic acid+glycine, P < 0.05). The folic acid+glycine supplement had no effect on litter size and embryo survival, but it tended to increase embryo DNA in multiparous YL sows (P = 0.06) but not in ML and nulliparous YL sows. Homocysteine was decreased by folic acid+glycine supplement in embryos from all sows, but in endometrium, the folic acid+glycine effect was dependent on parity (nulliparous x folic acid+glycine, P < 0.05). The effects of folic acid+glycine on litter size and embryo development and survival and some aspects of folate metabolism suggest that the basal dietary content of folic acid+glycine was adequate for ML and nulliparous YL sows but not to optimize embryo development in YL multiparous sows.  相似文献   

3.
Summary

The variation in the length of gestation, the period from mating until parturition, was studied in 77 dogs of different breeds; the time for mating was determined by measuring peripheral blood progesterone levels. The mean length of gestation was 62.1 ± 0.2 (S.E.M.) days, with a variation of 11 days. The number of pups appeared to influence the length of gestation. Length of gestation was negatively correlated (r = ‐0.96, P < 0.001, n = 44) with litter size in litters with 7 or fewer pups. The intra‐breed variation in length of gestation in the five breeds represented by five or more bitches was 3 ‐ 6 days. The mean gestation of Alsatians (60.1 ± 0.5, n = 9) was shorter (P < 0.005) than that of the other breeds combined (62.3 ± 0.3, n = 68). The primiparous/multiparous status of the bitch did not influence the length of gestation.  相似文献   

4.
OBJECTIVES: To investigate the influence of season and breed on reproductive parameters in bitches raised under tropical climatic conditions. METHODS: Over a seven year period, from 1998 to 2004, 310 oestrous periods of 53 bitches were observed. The dogs were of various breeds; dobermann (number of bitches/number of oestrous cycles) (n=2/19), German shepherd dog (n=35/211), Labrador retriever (n=14/68) and Rottweiler (n=2/12). In 250 of the 310 oestrous periods, natural matings took place on days 9 and 11 after the onset of pro-oestrus. The whelping rate was analysed for bitches of each breed. Variables, including breed and the whelping rate, by month of the year, were used for analysis of the inter-oestrus interval, gestation length, total number of pups born, number of live pups born and the weight of the pups at birth. RESULTS: A low frequency of oestrous activity was found during the summer. Breeding dogs in the summer resulted in a low whelping rate. No difference (P>0.05) was seen in the whelping rate of each breed: dobermann (70.5 per cent), German shepherd dog (61.5 per cent), Labrador retriever (67.9 per cent) and Rottweiler (100 per cent). The Labrador retriever had a longer inter-oestrus interval (252 [114] and 190 [61] days) (P<0.01) and a larger litter size (8.2 [1.8] and 6.6 [2.8]) (P<0.05) than the German shepherd dog. CLINICAL SIGNIFICANCE: The environmental factors in summer tend to reduce oestrus incidence and fertility in the bitches. According to litter size, the Labrador retriever seems to have a more efficient reproductive performance than the German shepherd dog. The Labrador retriever had a longer inter-oestrus interval than the German shepherd dog.  相似文献   

5.
The Kunming dog is the first and only working dog breed from China to be recognized worldwide. As a domestic working dog, its excellent working performance has been well established; however, its normal reproductive parameters are not well understood. Therefore, this study was conducted to document the main reproductive parameters of this purebred working dog in field breeding conditions. Data on 1004 heats (753 with mating) from 203 bitches between 2008 to 2014, were collected and analyzed. The pregnancy rate and whelping rate was 79.42% and 75.30%, respectively. Finally, for 567 litters (4298 puppies), the mean litter size was 7.19 ± 0.12 puppies (range 1–15). The mean gestation period and birth weight were approximately 61.64 ± 0.10 days and 407.25 ± 1.21 g. The mean sex ratio was 1.03 males to 1.00 female. Estrus occurred throughout the year with no significant differences between seasons and months (P > 0.05), which confirms that Kunming dogs are non‐seasonal breeders; births occurred in every month of the year. Pregnant bitches exhibited significantly longer inter‐estrus intervals than non‐pregnant bitches (220.85 ± 2.05 vs. 180.19 ± 2.94 days, P < 0.05). Bitch parity influenced litter size, and the gestation length and birth weight of the puppies were negatively affected by litter size. This study helps elucidate the reproductive potential of this breed and provides reference values for reproductive performance in the Kunming dog.  相似文献   

6.
The composition of the normal staphylococcal flora of bitches and their litters held in a breeding unit was studied. The animals were sampled at a number of sites using moistened swabs. Six bitches were sampled daily, for 10 days, before whelping and then, together with four puppies per litter, at whelping (day 11) and at 1 and 7 days thereafter. Staphylococcus intermedius formed the predominant staphylococcal isolate. S. intermedius counts at the oral and nasal sites on the bitches did not change markedly before whelping and remained low (< 6 cfu/swab). Significant rises in the oral counts on both the bitches (P < 0.05) and puppies (P < 0.001) were then observed after whelping (days 11-18). Abdominal counts on both the bitches and puppies also rose (P < 0.001) after whelping. S. intermedius counts at the vaginal vestibulum of the pregnant bitches were found to be higher than at any other site sampled and did not alter markedly until whelping when a decrease (P = 0.05; days 10-12) was observed. S. intermedius was not found at the anal site in any of the six bitches and only transiently colonized five of the puppies.  相似文献   

7.
Two juvenile (9 months) and two adult (3 years) beagle bitches were injected with five doses (250 i.u. per dose) of pregnant mare serum gonadotrophin (PMSG) on alternate days. Plasma oestrogen concentrations rose in all bitches. In one adult bitch plasma progesterone concentrations remained basal and no signs of oestrus were shown; in the other there was a slight elevation of circulating progesterone values and she showed oestrus but did not conceive. Both the young bitches came into heat and had multiple ovulations, producing very high plasma progesterone concentrations. One of them conceived, and at laparotomy on the thirty-sixth day after the first mating seventeen conceptuses were seen; 14 days later ovarohysterectomy was performed and only five foetuses remained in the uterus.  相似文献   

8.
Fifty‐five New Zealand white × California cross‐bred female rabbits were used to study the effect of protein level and flushing method on the reproductive performance of rabbits. The treatments consisted of three protein diets (18, 20 and 24% crude protein (CP)) and three flushing methods in a 3 × 3 factorial design. The flushing methods consisted of (i) flushing multiparous does and feeding a 16% CP diet during pregnancy; (ii) flushing multiparous does and feeding an 18% CP diet during pregnancy; and (iii) flushing nulliparous does and feeding an 18% CP diet during pregnancy. Flushing rabbits with different levels of protein did not significantly affect gestation length, litter size and mortality of kits. The trend showed an increase in litter weight with the increase in protein level from 18 to 24%. However, kits from does flushed with 24% CP had a higher individual kit weight gain than those on 20 and 18% CP. Gestation length, total litter size at birth, number of kits dead at birth and number of kits dead at 21 days post‐partum were not affected by flushing methods. There was, however, a significant effect of the flushing method on the number of kits alive at birth, and 7, 14 and 21 days post‐partum. Nulliparous does flushed and maintained on 18% CP during pregnancy had a significantly higher number of kits alive at birth, and 7, 14 and 21 days post‐partum. Litter weight was significantly higher for nulliparous does at 7, 14 and 21 days compared with that of multiparous does flushed and placed on a 16 or 18% CP diet during pregnancy. Protein intake during pregnancy had a significant effect on litter birthweight. Nulliparous and multiparous does flushed and placed on an 18% CP diet during pregnancy had a significantly higher litter birthweight than multiparous does flushed and placed on a 16% CP diet during pregnancy. The effect of protein level during pregnancy on the number of kits alive at birth was not significant. There was no interaction between protein level and flushing method on the reproductive performance of rabbits.  相似文献   

9.
The combination of a dopamine agonist, caber-goline, and a synthetic analogue of prostaglandin F2a, cloprostenol, was used to induce termination of pregnancy from day 25 after the estimated luteinising hormone surge (day 27 ± 4 after the first mating) in five mature beagle bitches. Caber-goline was administered orally at 5 μg/kg daily and cloprostenol was injected subcutaneously at 1 μg/kg every other day. Treatment efficacy, in terms of pregnancy termination, was 100 per cent. Termination always took place by resorption of the fetuses. No side effects were observed. A mean of three injections of cloprostenol and nine days of cabergoline treatment was necessary to eliminate all signs of gestation. Termination was in each case accompanied by a decline in plasma progesterone (to less than 1 ng/ml) within 72 hours of initiation of treatment. In a control group of five, untreated bitches, plasma progesterone remained elevated throughout a corre-  相似文献   

10.
Twelve anestrous adult Greyhound bitches were used to study a regimen for induction of estrus. Once daily, 7 bitches were given diethylstilbestrol (DES; 5 mg, PO) until sanguineous vaginal discharge and vulvar edema were observed (designated as day 1 of proestrus) and for 2 days thereafter. If no response was elicited after 7 days, a doubled DES dose was given for up to an additional 7 days. Luteinizing hormone (5 mg, IM) was given on day 5 of proestrus, and follicle-stimulating hormone (10 mg, IM) was given on days 9 and 11 of proestrus. Bitches were bred once on day 13. Five bitches were used as a control group; they were given candy tablets for 7 days (first day on tablets, treatment day 1) and 0.9% NaCl (1.0 ml, IM) on treatment days 12, 16, and 18. The 7 bitches treated with DES had a mean proestrus period of 7.7 days and a mean estrus period of 5.7 days up to the day of mating. After mating, they had a mean gestation interval of 64 days and delivered a mean of 4 pups/litter. In 5 bitches, initial treatment with 5 mg of DES/day induced proestrus within 7 days; however, in 2 bitches, additional treatment with 10 mg of DES/day was needed for 5 and 6 days, respectively. Serum estradiol-17 beta and progesterone concentrations remained at base line during the period of DES treatment. Concentrations of both hormones increased after injection with luteinizing hormone and remained high for the next 4 days.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

11.
An epidemiological survey undertaken in Kenya indicated that 2 previously well-established factors, namely decline in reproductive efficiency with age, and non-seasonality of canine reproductive parameters, hold true for German shepherd (GSD) bitches in Kenya. Data collection forms were distributed to randomly selected GSD breeders and information so obtained was verified using East African Kennel Club records. Whelping was recorded throughout the year. The litter size varied from 1 to 14 pups per litter with a mean of 6.3 +/- 0.4 SD puppies. Records of 567 whelpings and 3592 puppies were studied. The mean monthly whelping rate was 47.3 +/- 7.2. There was no significant difference in the mean litter size by month (P < 0.05).  相似文献   

12.
Data relating to reproductive parameters of German shepherd bitches were collected from registered German shepherd dog (GSD) breeders with information kept over a 15-year period (1982-1997). The information obtained was verified using the East African Kennel Club records. A total of 594 bitches from 280 breeders were recorded. From these, 798 heats were observed, 594 of which were used for breeding, resulting in 3592 puppies. The mean age at puberty was 519.0 +/- 41 days. Heats occurred throughout the year, although significantly (P < 0.05) higher and lower incidences were observed in October and April respectively Pregnancy significantly (P < 0.01) increased interoestrous interval, which was 247.8 +/- 99.6 and 183 +/- 52 days among bred/pregnant and non-bred bitches respectively. Most bitches in oestrus (73.7%) were bred, and breeding was carried out throughout the year, with a distribution closely related to that of heat incidence. Subsequently, whelping occurred throughout the year, and 95.5% of the bitches that were mated whelped. A mean gestation period of 60.6 +/- 5.1 days was observed. The mean litter size was 6.4 +/- 0.4 puppies, and did not differ significantly between months. The preweaning losses were low, with 2.3% stillbirths, 0.9% culls and 11.4% mortalities.  相似文献   

13.
Sixteen farms having an average lactation length between 14.9 and 18.9 days were selected based upon producers' willingness to keep records of production and lactation feed intake. Data contained 9162 subsequent litter-size records abstracted from computerized production information-system files and lactation feed-intake records. Two-way interactions between the associations of parity and lactation length, and parity and weaning-to-conception interval with subsequent litter size were found in the same statistical model. Subsequent litter size did not increase in parities 1 and 2 as lactation length increased – but subsequent litter size in sows of parities 3–6 increased. In only parity 1, sows with weaning-to-conception interval 6–12 days produced 0.5 fewer pigs at subsequent farrowing than those with weaning-to-conception interval 1–5 days. However, in multiparous sows, no difference in subsequent litter size was found between weaning-to-conception intervals 1–5 and 6–12 days.  相似文献   

14.
Sows mated in summer produce a greater proportion of born-light piglets (<1.1 kg) which contributes to increased carcass fatness in the progeny population. The reasons for the low birth weight of these piglets remain unclear, and there have been few successful mitigation strategies identified. We hypothesized that: 1) the low birth weight of progeny born to sows mated in summer may be associated with weight loss during the previous summer lactation; and 2) increasing early gestation feed allowance for the sows with high lactational weight loss in summer can help weight recovery and improve progeny birth weight. Sows were classified as having either low (av. 1%) or high (av. 7%) lactational weight loss in their summer lactation. All the sows with low lactational weight loss (LLStd) and half of the sows with high lactational weight loss received a standard gestation feeding regime (HLStd) (2.6 kg/d; day 0–30 gestation), whereas the rest of the sows with high lactational weight loss received a compensatory feed allowance (HLComp) (3.5 kg/d; day 0–30 gestation). A comparison of LLStd (n = 75) versus HLStd sows (n = 78) showed that this magnitude of weight loss over summer lactation did not affect the average piglet or litter birth weight, but such results may be influenced by the higher litter size (P = 0.030) observed in LLStd sows. A comparison of HLStd versus HLComp (n = 81) sows showed that the compensatory feeding increased (P = 0.021) weight gain of gestating sows by 6 kg, increased (P = 0.009) average piglet birth weight by 0.12 kg, tended to reduce (P = 0.054) the percentage of born-light piglets from 23.5% to 17.1% but reduced the litter size by 1.4 (P = 0.014). A subgroup of progeny stratified as born-light (0.8–1.1 kg) or -normal (1.3–1.7 kg) from each sow treatment were monitored for growth performance from weaning until 100 kg weight. The growth performance and carcass backfat of progeny were not affected by sow treatments. Born-light progeny had lower feed intake, lower growth rate, higher G:F, and higher carcass backfat than born-normal progeny (all P < 0.05). In summary, compensatory feeding from day 0 to 30 gestation in the sows with high weight loss during summer lactation reduced the percentage of born-light progeny at the cost of a lower litter size, which should improve growth rate and carcass leanness in the progeny population born to sows with high lactational weight loss.  相似文献   

15.
A cooperative experiment to evaluate biotin addition to sow diets was conducted at three research stations using 303 litters. Primiparous and multiparous sows (overall average parity 2.8) were fed a 14% CP corn-soybean meal diet (140 micrograms/kg biotin), with or without supplemental biotin (330 micrograms added biotin per kg feed), throughout gestation and lactation. As many sows as possible were fed their respective diets through three successive parities. During gestation, sows were given from 1.82 to 2.27 kg of feed per day, depending on environmental conditions; during lactation sows had ad libitum access to feed. Supplemental biotin had no effect (P greater than .35) on sow weights at breeding, at d 109 of gestation, at farrowing or at weaning. No differences were found in litter size at birth (P greater than .18), but at d 21 of lactation, sows fed the diet containing supplemental biotin had larger litters than sows fed the unsupplemented diet (9.4 vs 8.7 pigs, respectively; P = .01). Pig weights at birth and d 21 of lactation were not affected (P greater than .20) by dietary treatment. Biotin supplementation did not affect (P greater than .28) the length of the interval from weaning to estrus. No evidence was found that feet cracks or bruises were reduced by biotin supplementation. The results indicate that biotin supplementation of a corn-soybean meal diet during gestation and lactation increased the number of pigs at d 21 of lactation, but it did not decrease the incidence of foot lesions.  相似文献   

16.
OBJECTIVES: To compare the accuracy of two ultrasonographic measurements, inner chorionic cavity diameter and biparietal diameter, for the prediction of parturition date in small and medium size bitches. The effects of litter size and fetal sex ratio on the accuracy of the prediction were also investigated. METHODS: Ultrasonographic examinations were performed on pregnant bitches and, depending on the stage of pregnancy, the inner chorionic cavity diameter and biparietal diameter were measured. The mean value of the data of each structure was calculated and the predicted day of parturition was obtained by the application of equations derived from growth curves we previously developed for different size bitches. RESULTS: The parturition term was predicted with similar accuracy during early gestation, by the measurement of inner chorionic cavity diameter, as well as during late gestation, by the measurement of biparietal diameter. Litter size affected only biparietal diameter accuracy, whereas fetal sex ratio did not influence the estimation of the day of parturition. CLINICAL SIGNIFICANCE: Inner chorionic cavity diameter and biparietal diameter were equally reliable parameters in obtaining a reasonably accurate prediction of parturition date at any gestational period at which a bitch is examined.  相似文献   

17.
OBJECTIVE: To determine growth of the alpaca conceptus during early gestation, using ultrasonography. ANIMALS: 40 pregnant alpacas (20 multiparous, 20 nulliparous). PROCEDURE: Transrectal ultrasonography with a 5-MHz probe was performed 3 times weekly from days 7 through 45 after copulation (day of copulation = day 0). Blood samples were collected for progesterone assay on days of ultrasonography. RESULTS: Forty embryonic vesicles and embryos were identified and measured. Embryonic vesicles were first detected on day 12 after copulation and appeared spherical. Cumulative percentage of embryonic vesicles detected was 50, 82.5, and 100% on days 12, 14, and 16, respectively. Embryos were first detected by day 22 and heartbeats by day 24. Similarly, cumulative percentage of embryos detected was 17.5, 82.5 and 100% for 22, 24, and 26 days after copulation, respectively. Embryonic vesicles occupied both uterine horns beginning on day 19. A positive correlation existed between length and width of embryonic vesicles. Size of embryonic vesicles and embryos and progesterone concentrations did not differ between multiparous and nulliparous females. Five sets of twins were detected from days 21 through 33 after copulation, but the conceptus identified in the right uterine horn became nondetectable between days 28 and 33. CONCLUSIONS AND CLINICAL RELEVANCE: Ultrasonography was useful in detecting the earliest appearance of alpaca embryonic vesicles and determining the changes in growth from days 12 through 45 after copulation. Embryos were first detected by day 22. Transrectal ultrasonography was not harmful to animals and did not provoke embryonic death in this study.  相似文献   

18.
An analysis of 319 interoestrous intervals of 36 beagles, 36 German shepherd dogs and 20 labrador retrievers was made to study the influence of whelping on the length of this interval and the within-year variation in length of interoestrous intervals and timing of the oestrous periods. The mean interoestrous interval was significantly longer for beagles (247±5 days) than for German shepherd dogs and labrador retrievers (both 198±5 days)(P<0–001). For bitches that had not whelped there were no significant differences between breeds (beagles 172+10; German shepherd dogs 166±6; and labrador retrievers 172±7 days). The mean interoestrous interval after whelping was significantly lengthened in all breeds (P<0–001). This increase was more pronounced for beagles (84 days)(P<0–001) than for German shepherd dogs (58 days) and labrador retrievers (52 days). Heat periods were evenly distributed over the year for the labrador retrievers and German shepherd dogs that were kept as family pets. For the beagles kept as a colony and housed outdoors without heating or supplementary light, there were significant differences between months (P<0001), with a peak in May. The longest interoestrous intervals were found in beagle bitches that had been in oestrous and whelped during autumn.  相似文献   

19.
An accurate timing of parturition is very useful for managing canine parturition. It is generally accepted that parturition in bitches occurs between 64 and 66 days after the luteinizing hormone peak. In this retrospective study, we determined pregnancy length in different breeds and its influencing factors dating it from the estimated day of ovulation (EDO), defined as the day when peripheral plasma level of progesterone (P4) reaches 6 ng/ml. From January 2001 to December 2006, 162 pregnancies in 151 bitches of 53 different breeds were followed. Different parameters concerning the bitch, the litter, the type of semen and the type of reproduction were studied. The mean estimated pregnancy length in the bitch from EDO to parturition was 63.1±2.1 days. The main influencing factors for the pregnancies studied were the breed, the size of the bitch and the number of puppies within the litter.  相似文献   

20.
Ninety-one primiparous and multiparous sows and their pigs were used to evaluate the effects of a novel carbohydrate- and protein-based feed ingredient (Nutri-Pal, NP) on sow and litter performance during lactation. Nutri-Pal is a feed supplement for sows that consists of a blend of milk chocolate, brewer's yeast, whey products, and glucooligosaccharides. The dietary treatments consisted of a corn-soybean meal control and a corn-soybean meal plus 5% NP fed from d 110 of gestation to weaning. The diets were formulated to be equal in total Lys and ME. Sows were allotted to treatment based on parity, body weight, and the date of d 110 of gestation. There were 46 and 45 sows per treatment over four farrowing groups. Litters were standardized to 10 pigs and weighed within 1 d of farrowing, and all sows weaned at least 8 pigs at an average age of 21 d. Sows were weighed on d 110 of gestation, d 1 postfarrowing, and at weaning. Sows were fed three times daily during lactation. Sows were checked twice daily after weaning for signs of estrus. The weaning weight of sows fed NP was increased (P < 0.10) compared with those fed the control diet. Sows fed the control diet tended (P = 0.11) to lose more weight per day from d 110 of gestation to weaning than the sows fed NP. Otherwise, sow response variables (sow weight on d 110 of gestation and d 1 postfarrowing, d 110 of gestation to d 1 postfarrowing and lactation weight change per day, d 110 of gestation to d 1 postfarrowing, lactation, and total feed intake, days to estrus, pigs born alive or dead, and litter and average pig birth weight) were not affected (P > 0.10) by diet. There were no effects (P > 0.10) of diet on litter performance response variables (pigs weaned, litter and average pig weaning weight and gain, and survival percent). The NP feed ingredient had minor effects on sow productivity, but it did not affect litter productivity indices.  相似文献   

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