首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 21 毫秒
1.
OBJECTIVE: To determine whether administration of killed West Nile virus vaccine was associated with pregnancy loss among broodmares. DESIGN: Retrospective cohort study. ANIMALS: 595 mares. PROCEDURE: Records of pregnant mares with known vaccination history from 4 farms were reviewed. Information obtained from 595 mares included mare's identification; farm; age; breed; reproductive status; last breeding date; date last known pregnant; vaccination date; age of conceptus at vaccination; vaccination during the early embryonic, early fetal, and late fetal periods; and whether an early embryonic death (EED), early fetal loss (EFL), or late fetal loss (LFL) occurred. The relationships between the dichotomous outcomes of loss (eg, EED, EFL, LFL) and independent categoric variables (eg, vaccination during the early embryonic, early fetal, or late fetal periods) were examined. RESULTS: Vaccination of pregnant mares during any period of gestation was not associated with increased incidence of pregnancy loss. CONCLUSIONS AND CLINICAL RELEVANCE: Many mares are already pregnant at the onset of mosquito season, when mares are more likely to be vaccinated than at other times. Our findings provide evidence that vaccine administration will not compromise pregnancy in horses.  相似文献   

2.
OBJECTIVE: To identify factors associated with excessive proportions of early fetal losses associated with mare reproductive loss syndrome in central Kentucky during 2001. DESIGN: Case-control study. PROCEDURE: Questionnaires were used to collect information on farm-, pasture-, and individual animal-level factors purportedly associated with mare reproductive loss syndrome. Data were collected for 133 farms (97 with excessive proportions of early feta losses and 36 control farms) representing 6,576 mares. RESULTS: Factors significantly associated with an increased risk of excessive early fetal losses were exposure to moderate to high concentrations of Eastern tent caterpillars, exposure to cherry trees, farm size > or = 50 broodmares, being bred during February 2001, and frequent exposure to waterfowl. Feeding hay to mares outside was associated with a decreased risk of excessive proportions of early fetal losses. Pasture composition and management factors were not significantly different between affected and control pastures. Individual animal-level factors were investigated on 6 farms representing 340 mares, and age, parity, and pre- and postbreeding treatments were not significantly associated with risk of early fetal loss. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that limiting exposure to Eastern tent caterpillars and cherry trees and feeding hay to mares outside may help decrease the risk of excessive proportions of early fetal losses associated with mare reproductive loss syndrome.  相似文献   

3.
Records of 1,009 pregnancies in 574 foaling, barren and maiden Thoroughbred mares on a single stud farm, over a period of 12 years were examined. The farm is situated in the eastern Cape Province of South Africa, at an elevation of 1,800 m, and in an area of climatic extremes. Records of 604 pregnancies in 249 foaling Thoroughbred mares were examined. For these purposes, those pregnancies in which a mare conceived in the same breeding season during which she had foaled were considered as pregnancies in foaling mares. Pregnancy was confirmed by rectal palpation by a single experienced practitioner. Of the 604 pregnancies examined, conceptus attachment occurred in the horn opposite the previously gravid horn in 345 cases (57%), and in the previously gravid horn in 259 cases (43%; P less than 0.005). Unobserved foetal loss after pregnancy diagnosis amounted to 30 (9%) in the former group, while in the latter group (pregnancy established in the postgravid horn) 46 pregnancies were lost (18%; P less than 0.005). This study confirmed that conceptus attachment tends to occur in the uterine horn opposite the previously gravid horn in foaling Thoroughbred mares conceiving during the same season. A significantly higher incidence of foetal loss accompanied conceptus attachment in the postgravid horn. Of 242 pregnancies in 162 previously barren mares, 95 (39%) occurred in the left uterine horn and 147 (61%) in the right horn (P less than 0.005). The incidence of pregnancy failure in this group was 7%. The side of attachment did not affect the rate of loss. Evaluation of the records of 163 maiden mares revealed that conceptus attachment occurred in the left uterine horn in 58 (36%) pregnancies and in the right horn in 105 (64%) pregnancies (P less than 0.005), which is consistent with previously reported observations. Pregnancy failure was recorded in 4% of maiden mares. Side of attachment did not influence rate of loss in this group.  相似文献   

4.
The records of 1630 mare years from 6 Thoroughbred stud farms in south eastern Australia were analysed for the years 1981 to 1986. Overall pregnancy and foaling rates were 83.9% and 69.3%, respectively. When calculated per served oestrous cycle, pregnancy and foaling rates were 54.7% and 43.1%, respectively. Pregnancy and foaling rates were higher (P < 0.001) for mares 3 to 10 years of age than for older mares. There was no difference in the pregnancy rates of maiden, barren and foaling mares. The foaling rate was significantly higher (P < 0.001) in mares that became pregnant during the first served oestrous cycle (77.8%) than in mares that needed two served oestrous cycles to become pregnant (65.4%). Of all diagnosed pregnancies, 19.5% were not completed. Pregnancy loss was lower (P < 0.05) in maiden (12.4%) than in barren (19.7%) or foaling (20.9%) mares. Twins were diagnosed in 7.8% of all pregnancies. If one conceptus was lost without external interference, 84.1% of pregnancies went to term. If one conceptus was manually crushed, 55.9% of pregnancies were maintained. If prostaglandin was used to terminate twin pregnancies, 60% of mares so treated produced foals the following year.  相似文献   

5.
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   

6.
A serological enzyme linked immunosorbent assay (ELISA) for equine antibodies to Borrelia burgdorferi, the causative agent of Lyme disease, was utilized on three groups of Thoroughbred mares 14 days after breeding. Group A mares were located in Kentucky, Groups B and C mares were in Florida.Group A were broodmares from a breeding farm, where early embryonic losses were reported by the farm to be substantially higher than previous years. Of 78 mares a total of 19 (24%) had experienced early embryonic resorption. The early embryonic loss rate was 47% (8/17) in the seropositive group and 18% (11/61) in the seronegative group. The excessive loss rate in the Lyme positive group was statistically significant, with the Chi-square test yielding a p value of .014.Group B had 51 mares that did not conceive on the first breeding; Group C consisted of 51 mares that became pregnant on the first breeding, and maintained pregnancy for at least 60 days. Group C was age and farm matched to serve as controls to Group B. Group B showed a higher incidence (22%) of elevated concentrations of antibodies against B burgdorferi, than did Group C mares (16%).  相似文献   

7.
REASONS FOR PERFORMING STUDY: There is a paucity of information on factors that influence placental development in the horse. Hypothesis: Changes in nutrition, particularly around the time of proliferative placental growth, can affect development of the placenta and fetal growth. OBJECTIVE: To investigate the effects of 2 planes of nutrition and an unforeseen infection-mediated nutritional insult on placental and fetal development in the mare. METHODS: Twenty maiden Thoroughbred fillies, age 3 or 4 years, mated to one Thoroughbred stallion, were maintained on either High or Moderate food intake throughout pregnancy. In mid-gestation all the mares unexpectedly became infected with Streptococcus equi and suffered varying degrees of weight loss as a consequence. Gross and stereological measurements of the placenta and measurements of foal birthweight, crown-rump length, ponderal index and plasma IGF-1 concentration were made at term. RESULTS: Gains in bodyweight during gestation were significantly higher in the High vs. the Moderate nutrition groups. Placental and fetal growth parameters were not influenced by the plane of nutrition. However, transient weight loss in mid-gestation from acutely reduced food intake resulted in morphological changes to the allantochorion and decreased foal birthweight. CONCLUSIONS: Excessive weight gain during gestation in maiden Thoroughbred fillies does not result in nutrient partitioning to the dam at the expense of the fetus. However, sudden weight loss in mid-gestation has detrimental effects on placental development which results in reduced fetal growth. POTENTIAL RELEVANCE: Clinicians should appreciate the likely effects of maternal infection and resulting weight loss on pregnancy outcome.  相似文献   

8.
Between February 15 and May 17, 2011, a total of 88 broodmares (10 maiden, 10 barren, and 68 foaling) maintained on pasture in southeast Texas were examined three times weekly (Tuesday, Thursday, Saturday) by transrectal palpation and ultrasonography. On Tuesday or Thursday, mares in estrus with uterine edema, a relaxed cervix, and a dominant follicle ≥34 mm in diameter were alternately assigned to treatment with the following: group (1) 2,500-unit human chorionic gonadotropin (hCG), intravenous; group (2) 1.0-mg BioRelease Histrelin (Biorelease Technologies, Lexington, KY), intramuscular; or group (3) 0.5-mg BioRelease Histrelin, intramuscular. Ovulation was confirmed by ultrasonographic examination. The percentage of mares ovulating within 2 days appeared to be similar between maiden, barren, and foaling mares, so responses for all mares were totaled for analysis. A nonsignificant trend for higher ovulation rates within 2 days was noted for both dose rates of histrelin compared with hCG treatment (31/37, 84%; 34/37, 92%; and 33/36, 92% for groups 1-3, respectively) (P = .45). Ovulatory responses appeared to improve for both products as the season progressed, yet no differences were detected between response rates to histrelin or hCG for any month (P ≥ .50). The use of 1.0- or 0.5-mg BioRelease Histrelin was found to be at least equally effective as hCG treatment for inducing ovulation within 2 days of treatment throughout the breeding season.  相似文献   

9.
Ultrasonographic pregnancy records of 195 mares from six Thoroughbred stud farms, over a period of 7 years were retrospectively analysed to assess the effect of various factors on embryonic vesicle (EV) fixation pattern and pregnancy outcome. Of the total of 746 pregnancies analysed, significantly (p < 0.01) more EV fixations were evident in the right uterine horn than in the left (53.35% vs 46.65% respectively). There was no significant effect of either, the side of ovulation, or age of the mare, on the side of EV fixation. However, EV fixation, was significantly (p < 0.001) more likely to occur in the right uterine horn in maiden and barren mares (65.75% vs 57.45% respectively). The age and reproductive status of the mare as well as foal heat breeding failed to demonstrate a consistent effect on pregnancy loss relative to the side of EV fixation. In lactating and foal heat bred mares, EVs were significantly (p < 0.0001) more frequently established in the contralateral horn to the one from which the mare delivered her most recent foal. In lactating mares, significantly (p < 0.05) higher embryonic and pregnancy losses were observed in the ipsilateral horn. In conclusion, (a) side of EV fixation was (i) independent of the side of ovulation and mare age (ii) significantly (p < 0.001) affected by reproductive status, (b) neither age of mare nor reproductive status had any effect on pregnancy loss rates relative to the side of EV fixation and (c) in lactating mares the EV had a greater chance of fixation and survival in the horn contralateral to the one from which the mare delivered her most recent foal.  相似文献   

10.
In Thoroughbred breeding, it is sometimes necessary to tranquilize a maiden mare to accomplish safe breeding by natural service. To determine whether tranquilization adversely affected fertility of maiden mares, pregnancy rates achieved in 792 matings of 531 maiden Thoroughbred mares were evaluated. One hundred sixty-three matings were accomplished after administration of a tranquilizer cocktail (20 mg acepromazine, 100 mg xylazine, and 10 mg butorphanol tartrate, injected intravenously), whereas 598 matings were accomplished without tranquilization. Pregnancy rate/cycle did not differ between maiden mares tranquilized before (64%; 105/163) and mares not tranquilized before mating (69%; 434/629) (χ2 = 1.048; P > .05). We concluded that tranquilization of maiden Thoroughbred mares immediately before mating did not adversely affect fertility.  相似文献   

11.
Between February 14 and April 26, 2012, 75 broodmares (7 maiden, 11 barren, and 57 foaling) maintained on pasture in southeast Texas were examined three times weekly (Tuesday, Thursday, Saturday) by transrectal palpation and ultrasonography. On Tuesday or Thursday, mares in estrus with uterine edema, a relaxed cervix, and a dominant follicle ≥30-mm diameter were alternately assigned to treatment with 0.5 mg of intramuscular (IM) histrelin (group 1) or 0.25 mg IM histrelin (group 2). Ovulation was confirmed by ultrasound examination. No differences in proportion of maiden plus barren (96%) compared to foaling (86%) mares ovulating within 2 days was found (P > .10); therefore, responses for all mares were combined for analysis. No differences in ovulation rates within 2 days were noted for 0.5 mg histrelin compared to those for 0.25 mg histrelin treatment (42 of 46, 91%; 44 of 52, 85%; P > .10). No differences were detected between response rates to 0.5 or to 0.25 mg histrelin for any month (P > .10). The use of 0.5 or 0.25 mg histrelin were found to be effective treatments for inducing ovulation within 2 days of administration throughout the early breeding season.  相似文献   

12.
Effects of farm management, breed, mare age, gestation duration, and climatologic factors on colostral specific gravity, colostral IgG concentration, and foal serum IgG concentration were evaluated. Climatologic variables measured were daily maximal, minimal, and mean air temperature, precipitation, average relative humidity, and total solar radiation. Presuckle, postpartum colostrum samples were collected from 140 Standardbred, 94 Thoroughbred, and 59 Arabian mares from January through June during 1985 and 1986. Thoroughbred (farm A, n = 61; farm B, n = 33) and Arabian (farm C, n = 45; farm D, n = 14) mares were located in Ocala, Fla; Standardbred mares (farm E) were in Montgomery, NY. Mares from farms A, B, D, and E foaled in box stalls, and mares from farm C foaled in sand paddocks. Mares with premature lactation greater than 12 hours were not included in the study. Foals were clinically normal at birth and suckled colostrum without assistance within 2 hours of parturition. Specific gravity of presuckle colostrum samples was measured by use of an equine colostrometer. Blood samples were collected 18 hours after parturition from 253 of the 293 foals (n = 45, 25, 32, 13, 138 on farms A through E, respectively) to determine serum concentration of IgG. The IgG concentrations in colostrum and serum were measured by single radial immunodiffusion. Data were analyzed by multiple regression or chi 2 analysis. The most important determinants of foal serum IgG concentration were the IgG content and specific gravity of presuckle colostrum samples (P less than 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

13.
Palpation records of 155 Throughbred broodmares maintained on one of seven farms (3–80 mares per farm) that were administered deslorelin on one or more estrous cycles (204 treated cycles) during the 1999 breeding season were retrospectively examined. Some deslorelin-treated mares were also treated with hCG (2500 units intravenously), or had no ovulation-inducing drugs administered, during different estrous cycles of the same season. Most mares were treated with an ovulation- inducing drug after returning to their resident farm following breeding and were subsequently examined by transrectal ultrasonography daily until ovulation was confirmed, and again 13–14 and 15–16 days after ovulation for determination of pregnancy status.Per-cycle pregnancy rate for all 155 mares bred was 53%, and for all deslorelin breeding was 57%. Per-cycle pregnancy rates for mares ovulating 0–1 days, 1–2 days, and 2–3 days after treatment with deslorelin did not differ (P>0.05). Forty-six mares received more than one treatment during the breeding season, yielding 115 breedings (estrous cycles) for comparison of pregnancy rates among treatment. Per-cycle pregnancy rates for these mares did not differ among treatments (P>0.10).No differences due to treatment were detected in mean interval to ovulation (P>0.10). Mean interovulatory interval was longer for deslorelin-treated mares than for untreated or hCG treated mares (P>0.01). Eighty percent (80%) of deslorelin-treated mares had interovulatory intervals of 18–25 days, and 19% had interovulatory intervals>25 days. Ninety-seven percent (97%) of untreated or hCG-treated mares had interovulatory interovulatory intervals>25 days. More deslorelin-treated mares had extended (>25 days) interovulatory intervals than hCG- or nontreated-mares (P>0.05). In this group of Thoroughbred mares, it appeared that season (month) and management (farm) factors had only minor effects on the incidence of extended interovulatory intervals following use of deslorelin.  相似文献   

14.
OBJECTIVE: To identify factors associated with abortions during early gestation classified as mare reproductive loss syndrome (MRLS). DESIGN: Case-control study. ANIMALS: 324 broodmares from 43 farms in central Kentucky, including 121 mares from 25 farms that had early-term abortions (ETAs) associated with MRLS (case horses), 120 mares from the same farms but that did not abort, and 83 mares from 18 farms that were not severely Impacted by MRLS. PROCEDURE: Farm managers were interviewed to obtain data on various management practices and environmental exposures for the mares. Data for case and control horses were compared to identify risk factors for mares having MRLS-associated ETAs. RESULTS: Several factors increased the risk of MRLS-associated ETAs, including feeding hay in pasture, greater than usual amounts of white clover in pastures, more eastern tent caterpillars in pastures, abortion during a previous pregnancy, and sighting deer or elk on the premises. CONCLUSIONS AND CLINICAL RELEVANCE: Analysis indicates that certain characteristics of pastures predisposed mares to MRLS-associated ETAs. Methods for limiting exposure to pasture (keeping mares in stalls longer) during environmental conditions similar to those of 2001 (ie, sudden freezing in mid-April following warmer-than-usual springtime temperatures and larger-than-usual numbers of eastern tent caterpillars in and around pastures) should reduce the risk of mares having MRLS-associated ETAs. It was not possible to determine whether exposure to white clover or caterpillars were causal factors for MRLS or were merely indicators of unusual environmental conditions that resulted in exposure of mares to a toxic or infectious agent.  相似文献   

15.
Pregnancy loss in mares is thought to be a main problem associated with reproductive efficiency. To clarify the situation of pregnancy loss in Thoroughbred mares in Japan, the occurrence of pregnancy loss before and after 35 days of gestation was investigated with 1,476 Thoroughbred mares in Hidaka, Japan, from 2007 to 2009. Pregnancy loss on days 17-35 was determined by ultrasound examination between 17 and 35 days after the last mating. Follow-up surveys were conducted between 35 days and foaling to determine pregnancy loss on day 35 until foaling in 843 of these mares. Using multiple logistic regression analysis, we assessed the influence of mare age, reproductive status, twin pregnancy reduction, body condition score (BCS), estrus type in foaling mares (foal heat or not), progesterone therapy, and endometrial cysts on pregnancy loss rates on days 17-35 and on day 35 until foaling in this population of mares. The pregnancy loss rates on days 17-35 and on day 35 until foaling were 5.8% and 8.7%, respectively. The overall pregnancy loss rate (day 17 until foaling, including parturient losses) was 14.7%. Risk factors for pregnancy loss included decrease in BCS between 17 and 35 days, <5 BCS at day 35, mating during foal heat, and endometrial cysts. In all, 14.7% of pregnancies were lost between day 17 and birth, contributing significantly to reduced reproductive efficiency in Thoroughbred mares in Japan. These observations indicate that mares should be maintained at high BCS and should be prevented from mating in foal heat to decrease the pregnancy loss rates.  相似文献   

16.
Contents Fifty thoroughbred mares, located at Central-Southern Brazil near Sao Paulo (13 anestrous maiden, 18 anestrous barren mares and 19 postpartum mares) were treated with one to three injections, 48 hrs apart, of 2 mg of the novel PGF analog K 11941*, during the early part of the breeding season. Early season anestrus in these problem mares was compounded by the adverse effects of a drought. Plasma progesterone determinations revealed unexpectedly elevated plasma progesterone levels in 61.5% of the maiden mares, in 77.8% of the barren mares and in 68.4% of the postpartum mares (20 to 25 days postpartum). Treatments with K 11941 initiated luteolysis, heat and ovulations in 91.4, 45.5 an 63.3% of these mares, respectively, but initiated also heat and ovulation in 13% and 33% of mares with baseline progesterone levels. Treatments initiated covert and overt cyclic functions in 17 and 12 of those animals which did not conceive immediately. Fifteen animals with recurrent anestrus received further treatment with K 11941. Ten mares cycling silently were force bred when palpations indicated ovulatory follicles, and 7 conceived. Of the 50 mares treated, 38 became pregnant (76%: maiden mares: 76.9%; barren mares: 77.8% and postpartum mares: 73.7%) with breeding indices of 1.9, 1.36 und 1.57, respectively; and 37 mares gave birth to a live foal (74%), At the same stud, 138 control mares had a foaling rate of 82.6%.  相似文献   

17.
OBJECTIVE: To determine whether thyroid function was associated with pregnancy status in broodmares. DESIGN: Prospective study. ANIMALS: 79 Thoroughbred and Standardbred broodmares between 2 and 22 years old. PROCEDURE: Serum triiodothyronine (T3) concentration was measured before and 2 hours after i.v. administration of thyrotropin releasing hormone (TRH), and serum thyroxine (T4) concentration was measured before and 4 hours after TRH administration. Pregnancy status was monitored by means of transrectal ultrasonography beginning 16 days after ovulation. RESULTS: Baseline T3 and T4 concentrations varied widely. In all mares, serumT3 concentration increased in response to TRH administration. Serum T4 concentration increased in response toTRH administration in all but 2 mares. Pregnancy rate was 76%. Baseline and stimulated serum T3 and T4 concentrations were not significantly different between mares that became pregnant and those that did not. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that decreased thyroid function is uncommon in mares and poor thyroid function is not a common cause of infertility. Thus, the practice of indiscriminately treating broodmares with thyroid hormone to enhance fertility appears questionable at this time.  相似文献   

18.
AIM: To obtain initial baseline data on the management of Thoroughbred stud farms in the North Island of New Zealand. METHODS: Data on the management of Thoroughbred stud farms were collected from a sample of 22 stud farms located in the south Auckland/Waikato region (n=15) and lower North Island (n=7) of New Zealand, using a face-to-face survey. The studmaster provided information on the size, scope and management of the farms during the 2004/2005 breeding season. Analysis was based on the location of the farm and size of the breeding operation (number of resident mares). RESULTS: Effective farm size ranged from 20 to 526 ha and averaged 167 (standard error (SE) 36) and 88 (SE 49) ha in the south Auckland/Waikato and lower North Island areas, respectively. Some farms in the Auckland/Waikato region stood shuttle stallions. The median number of stallions per farm was three (range 0-9), and the median mare-to-stallion ratio was 43 (range 10-250). The farms had a mean of 50 (range 7-180) wet mares and 21 (range 0-100) dry mares. The number of mares per breeding stallion increased with increasing size of breeding operation (p=0.04), being 28 (95% confidence interval (CI) = 10-56) vs 40 (95% CI=16-74) vs 74 (95% CI=44-113) for moderate (or=200 mares in total) operations, respectively. Seventy-one percent of farms aimed to breed dry mares early in the breeding season, and used a combination of lights, hormone therapy, and rising plane of nutrition to achieve this. Foaling took place in foaling paddocks monitored using a night foaling attendant (17/22) or with foaling alarms (5/22). At birth, 17/22 studmasters routinely administered antibiotics, 14/22 administered tetanus antitoxin, 9/22 administered an enema to foals, and 2/22 did not routinely administer prophylactic treatments. Weaning occurred at 5 (range 3.7-7) months of age, and foals were confined to a box for 1-2 weeks on 16/22 farms. Weaned foals were drenched with anthelmintics every 7 (range 4-9) weeks, and were fed 2.9 (range 1-6) kg of concentrate feed while at pasture until intensive management associated with preparation of the horses for auction began 13 (range 6-20) weeks before the yearling sales. Eight farms weighed the weanlings, at least monthly, to monitor growth. CONCLUSIONS AND CLINICAL RELEVANCE: The management of Thoroughbred horses was relatively consistent throughout the regions surveyed. Utilisation of breeding stallions tended to be more efficient on the larger stud farms in the south Auckland/Waikato region. Even though foals are grown at pasture they are often provided with large quantities of concentrate feed.  相似文献   

19.
AIM: To obtain initial baseline data on the management of Thoroughbred stud farms in the North Island of New Zealand.

METHODS: Data on the management of Thoroughbred stud farms were collected from a sample of 22 stud farms located in the south Auckland/Waikato region (n=15) and lower North Island (n=7) of New Zealand, using a face-to-face survey. The studmaster provided information on the size, scope and management of the farms during the 2004/2005 breeding season. Analysis was based on the location of the farm and size of the breeding operation (number of resident mares).

RESULTS: Effective farm size ranged from 20 to 526 ha and averaged 167 (standard error (SE) 36) and 88 (SE 49) ha in the south Auckland/Waikato and lower North Island areas, respectively. Some farms in the Auckland/Waikato region stood shuttle stallions. The median number of stallions per farm was three (range 0.9), and the median mare-to-stallion ratio was 43 (range 10.250). The farms had a mean of 50 (range 7.180) wet mares and 21 (range 0.100) dry mares. The number of mares per breeding stallion increased with increasing size of breeding operation (p=0.04), being 28 (95% confidence interval (CI) = 10.56) vs 40 (95% CI=16.74) vs 74 (95% CI=44.113) for moderate (≤70 mares), medium (90–199 mares) and large (≥200 mares in total) operations, respectively. Seventy-one percent of farms aimed to breed dry mares early in the breeding season, and used a combination of lights, hormone therapy, and rising plane of nutrition to achieve this.

Foaling took place in foaling paddocks monitored using a night foaling attendant (17/22) or with foaling alarms (5/22). At birth, 17/22 studmasters routinely administered antibiotics, 14/22 administered tetanus antitoxin, 9/22 administered an enema to foals, and 2/22 did not routinely administer prophylactic treatments. Weaning occurred at 5 (range 3.7–7) months of age, and foals were confined to a box for 1–2 weeks on 16/22 farms. Weaned foals were drenched with anthelmintics every 7 (range 4–9) weeks, and were fed 2.9 (range 1–6) kg of concentrate feed while at pasture until intensive management associated with preparation of the horses for auction began 13 (range 6–20) weeks before the yearling sales. Eight farms weighed the weanlings, at least monthly, to monitor growth.

CONCLUSIONS AND CLINICAL RELEVANCE: The management of Thoroughbred horses was relatively consistent throughout the regions surveyed. Utilisation of breeding stallions tended to be more efficient on the larger stud farms in the south Auckland/Waikato region. Even though foals are grown at pasture they are often provided with large quantities of concentrate feed.  相似文献   

20.
The objective of this retrospective study was to evaluate the effect of management strategies aiming to improve animal well‐being on pregnancy and embryonic death (ED) rates. Breeding records of a cohort of 1206 Thoroughbred mares brought to a stallion station facility, to be bred with the stallions housed there, were evaluated during ten breeding seasons. Mares were blocked according to management strategies in two groups: Stress and Relax. Strategies used to improve animal well‐being (Relax group) were as follows: stopping the teasing routine, reducing or eliminating stall confinement, reducing the number of mares per group and maintaining herd stability during the breeding season. In barren mares, the pregnancy rate was higher in the Relax group (91.8%) when compared to the observed in Stress group (84.7%). However, no difference in pregnancy rates were observed (Stress = 85.2% vs. Relax = 86.2) in foaling mares. ED rate was higher in barren and foaling mares of the Stress group mares (25.5% and 26.8%, respectively) compared with the Relax group (16.1% and 14.7%, respectively). No significant differences were observed on foal heat pregnancy rate between groups; yet, the embryo loss on foal heat was significant reduced in Relax mares (Relax = 8.7% vs Stress = 24.5%). In conclusion, management strategies aimed to reduce social stress can reduce early pregnancy losses and the average cycles per pregnancy, improving reproductive performance in mares.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号