2 results
Seasonal variations in physiological and behavioural parameters in a bachelor group of stallion ponies (Equus caballus)
- M. C. G. Davies Morel, S. D. McBride, R. S. Chiam, A. McKay, E. Ely
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- Journal:
- Animal Science / Volume 82 / Issue 5 / October 2006
- Published online by Cambridge University Press:
- 09 March 2007, pp. 581-590
- Print publication:
- October 2006
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Animals living in temperate climates are continually adapting to seasonal demands of reproduction and survival. Whilst it is well documented that ruminants show seasonal changes in both reproductive and non-reproductive physiological and behavioural characteristics (reduction of metabolic rate and appetite during the winter with respective increases during spring and summer), this information has not been fully established in the non-ruminating ungulate species of Equidae. This may be important information from a practical management perspective since groups of equids are increasingly being kept in natural conditions for the purposes of conservation grazing.
The aim of this study, therefore, was to document the behavioural and physiological adaptive changes made by ponies during a 12-month period and to relate these to changes in forage availability and environment. Five mature pony stallions were kept in west Wales (4°5′W, 52°25′N) and monitored for 12 months. A range of physiological (testis size, body weight, condition score (CS), hoof growth, moult (M), pelage fibre length, depth and density) and behavioural measurements (foraging and non-foraging activities) were recorded along with monthly forage analysis (crude protein (CP), water-soluble carbohydrates (WSC)), dry matter (DM)) and environmental conditions (day length and minimum ambient temperature). All physiological measurements were significantly (P<0·001 to P<0·05, r2=0·16 to 0·69) related to day length and all except testis size, body weight and M were significantly related to minimum temperature, CS (P<0·001; r2=0·583), hoof growth (P<0·001; r2=0·457), pelage fibre length (P<0·001; r2=0·61), pelage fibre depth (P<0·001; r2=0·489) and pelage density (P<0·05; r2=0·192). Fewer significant relationships were observed in relation to forage characteristics; significances only obtained between CP and CS (P<0·001; r2=0·854), fibre length (P<0·01; r2=0·625) and pelage fibre depth (P<0·01; r2=0·624); between DM and CS (P<0·05; r2=0·352) and pelage fibre depth (P<0·05; r2=0·343); between WSC and pelage fibre depth (P<0·01; r2=0·55) and pelage fibre depth (P<0·05; r2=0·34). Behaviour results showed a significant relationship between time spent alert and day-length (P<0·05; r2=0·35) and between minimum ambient temperature and time spent eating (P<0·05; r2=0·37), locomotory behaviour (P<0·01; r2=0·53) and passive interaction (P=0·001; r2=0·63). A significant relationship was also reported between eating and CP (P<0·01; r2=0·53) as well as DM (P=0·01; r2=0·43). The ponies in this study demonstrated a series of adaptive changes during winter concomitant with energy conservation, however, forage availability and intake also decreased indicating lower energy input. Despite energy conserving adaptations it is unlikely that nutrient intake was adequate to account for the limited winter decline in CS and weight. In conclusion, it was considered that: (a) ponies demonstrated physiological and behavioural adaptation in response to environmental demands, (b) during winter ponies demonstrated behaviours indicative of a cost benefit analysis of expending energy in the pursuit of poor quality forage, (c) despite energy conserving adaptations, intake is unlikely to have been adequate to maintain the CS observed, and (d) reduction in metabolic rate and increased food conversion efficiency may be additional adaptations made during times of environmental challenge.
The occurrence and outcome of multiple ovulation and pregnancy in the Thoroughbred mare
- M C G Davies Morel, S Dennis
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- Journal:
- BSAP Occasional Publication / Volume 32 / 2004
- Published online by Cambridge University Press:
- 27 February 2018, pp. 199-201
- Print publication:
- 2004
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Multiple pregnancies (MP) are almost always the result of multiple ovulations (MO) (Ginther and Bergfelt, 1988). Twinning is the most common non-infectious cause of abortion in the mare (Roberts and Myhre, 1983) and represents a significant economic loss. As a consequence, further investigation into its occurrence and outcome is warranted in order to determine effective management practices.
Ultrasonic scanning was used to monitor and classify ovulation in 1582 Thoroughbred mares. Further ultrasonic scanning at Day 13 was used to identify and classify the resulting pregnancies (single pregnancy (SP), or MP)) in varying samples of mares. All MP mares underwent manual reduction of the smallest embryo at Day 13. 1170 mares, both SP and crushed MP, were monitored for the remainder of pregnancy with regard to pregnancy failure or success. Chi squared was used to test for significance throughout.