Gestation length and occurrence of daytime foaling of Standardbred mares on two stud farms in New Zealand.
Abstract: To examine the gestation lengths and occurrence of daytime foaling of Standardbred mares foaling outdoors at stud farms in Southland, New Zealand (latitude 45˚S). Methods: Data were collected prospectively at two commercial Standardbred stud farms (Farms A and B), during the 2008/9 and 2009/10 breeding seasons (October to February). For each foaling, the identity of the mare, date and time of foaling, gender of foal, time the mare passed the fetal membranes, time the foal stood, and foaling problems including dystocias, were recorded. The effect of farm, season, gender of foal, month of artificial insemination (AI) or foaling, age and parity of mare on gestation length, percentage of mares foaling during daylight hours, and percentage of foalings recorded as dystocia, were examined. Results: A total of 614 foaling records were obtained from 507 mares. For 594 foalings with complete records, mean gestation length was 349 (SE 0.5) days. Mean gestation length was shorter for fillies (347.8 (SE 0.6) days) than colts (350.3 (SE 0.6) days) p = 0.021) and decreased with month of AI, from October to February (p = 0.001). The time of foaling was bimodally distributed with the primary peak around 0200 hours and a secondary smaller peak around 1300 hours. The percentage of mares foaling in daylight was lower on Farm A (69/285 (24%)) than Farm B (128/313 (41%)) (p = 0.001). Colt foals were less likely to be born during the day than fillies (OR = 0.63; (95% CI = 0.44-0.88); p = 0.008), but there was no effect of age or parity of mare or month of foaling (p>0.05). Conclusions: Mean gestation length of mares in this study was longer than that previously reported from other countries. Longer gestation length decreases the time available for these mares to get back into foal in the same season. It is important that managers take this into account and ensure optimum conditions for conception; breeding at the first postpartum oestrus may be essential. There were more mares foaling in daylight hours on one stud than has previously been reported. Under these conditions mares should be monitored for foaling during daytime as well as at night.
Publication Date: 2011-12-20 PubMed ID: 22175428DOI: 10.1080/00480169.2011.632340Google Scholar: Lookup
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- Journal Article
Summary
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The research investigated the gestation lengths and occurrence of daytime foaling in Standardbred mares at two stud farms in New Zealand, revealing that mare gestation periods were longer than previously reported and more foaling occurred during daylight hours at one stud than previously seen.
Methodology
- The research was carried out prospectively at two commercial Standardbred stud farms in Southland, New Zealand, during the 2008/9 and 2009/10 breeding seasons.
- For each foal birth, details were recorded including the identity of the mare, date and time of foaling, gender of foal, time the mare passed the fetal membranes, time the foal stood, and any birthing problems.
- The data was analyzed to examine the effects of variables such as farm, season, gender of foal, month of artificial insemination (AI) or foaling, and age and parity of mare on gestation length, the number of mares foaling during daylight, and the percentage of birth complications.
Results
- Using 594 complete birth records, the average gestation length was determined as 349 days.
- Gestation length was found to be shorter for female foals and decreased with the month of AI, from October to February.
- Foal birth primarily occurred around 0200 hours and secondarily and lesser in frequency around 1300 hours.
- The percentage of mares foaling during daylight was lower in one farm than the other.
- Male foals were less likely to be born during the day, and age or parity of mare or month of foaling had no effect on this.
Conclusions
- The study concluded that the average gestation length of mares in this study was longer than previously reported elsewhere. This increased gestation length reduces the time available for these mares to conceive again in the same season.
- This indicates the need for managers to ensure optimum conditions for conception; breeding immediately after the first postpartum estrus may be crucial.
- Surprisingly, more mares foaled during daylight hours on one stud than has been reported previously, implying that mares should be carefully monitored for birth during both daytime and night.
Cite This Article
APA
Dicken M, Gee EK, Rogers CW, Mayhew IG.
(2011).
Gestation length and occurrence of daytime foaling of Standardbred mares on two stud farms in New Zealand.
N Z Vet J, 60(1), 42-46.
https://doi.org/10.1080/00480169.2011.632340 Publication
Researcher Affiliations
- Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Private Bag 11222, Palmerston North, New Zealand.
MeSH Terms
- Animals
- Circadian Rhythm
- Dystocia / veterinary
- Female
- Horses / physiology
- New Zealand
- Parturition / physiology
- Pregnancy
- Pregnancy, Animal
Citations
This article has been cited 4 times.- Manosalva DG, Grispoldi L, Spagnolo M, Crociati M. Delayed First Milking in Unassisted Overnight Calving Did Not Affect the Quality of Colostrum but Influenced Serum Brix Refractometry in Holstein Calves at Two Days of Life. Animals (Basel) 2022 Jun 28;12(13).
- Rosanowski SM, Carpenter TE, Adamson D, Rogers CW, Pearce P, Burns M, Cogger N. An economic analysis of a contingency model utilising vaccination for the control of equine influenza in a non-endemic country. PLoS One 2019;14(1):e0210885.
- Dembek KA, Hurcombe SD, Frazer ML, Morresey PR, Toribio RE. Development of a likelihood of survival scoring system for hospitalized equine neonates using generalized boosted regression modeling. PLoS One 2014;9(10):e109212.
- Meliani S, Benallou B, Halbouche M, Haddouche Z. Time of foaling in Arabian mares raised in Tiaret, Algeria. Asian Pac J Trop Biomed 2013 Jul;3(7):587-8.
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