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15
Maria Kulisa, Boguslawa Dlugosz, Katarzyna Makiela, Malgorzata Stochmal ©
Departament of Horses Breeding, Agricultural University 30-059 Krakow, al. Mickiewicza 24/28, Poland, e-mail: bdlugosz@ar.krakow.pl
THE INFLUENCE OF THE LENGTH OF INTERGESTATION PERIOD ON THE BIOMETRIC PARAMETERS OF THE FOALS
The aim of this research was to investigate the influence of the length of intergestation period on the biometric parameters of the foals after their birth. The research data was collected in 2005 in the state owned stud of purebred Arabians. Under research there came 75 mares and 245 foals in the years 1980 - 2005. The length of the intergestation period was calculated for each mare. The measurement of the following biometric parameters were taken from each foal within 2 - 3 days after their birth: the height at withers, circumference of chest and cannon bone. The length of the intergestation period depended on the mare's age. The shortest was among 5-year-old mares, the longest among 10-year-olds. The length of the intergestation period was statistically important to the circumference of chest and cannon bone, but had no influence on the height at withers. All three parameters of the foals born after 365-day-long intergestation period were the highest.
Key words: Arabian horses, length of intergestation, biometric parameters
Introduction. Among all the horse breeds all over the world, the purebred Arabians are considered to be one of the oldest. Particular beauty, high utility and breeding qualities of this breed are the result of the natural conditions under which this breed came into existence (Zwolinski 1980). Arabian mares have high fertility level, go in foal easily and have abundant milk supply. In healthy mares the first estrus following foaling appears within 7 - 9 days thereafter, and usually it ends in ovulation. It often happens that the estrus comes by unspotted as the mares do not show its outer symptoms. This fact has a great importance in planning the next mating. The omission of each consequitive estrus results in lengthening of the intergestation period. It is defined as the number of days between foaling and a successful mating (Bielanski et al. 2000). The longer the intergestation period, the slower breeding. Moreover, it has been revealed that the foals born with the best biometric parameters were the bravest on the racing tracks (Kuznik 2003).
Task, the aim of the article. The aim of this research was to investigate the influence of the length of intergestation period on the biometric parameters of the foals after their birth.
Material and methods. The research data was collected in 2005 in the state owned stud of purebred Arabians. Under research there came 75 mares and 245 foals in the years 1980 - 2005. The length of the intergestation period was calculated for each mare. Next, this period was divided into 5 sub-periods and 5 groups of mares
© Maria Kulisa, Boguslawa Dlugosz, Katarzyna Makiela, Malgorzata Stochmal, 2009
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were selected: group A - the intergestation period up to 14 days, group B - up to 40 days, group C - up to 60 days, group D - up to 365 days, group E - over 365 days. The measurement of the following biometric parameters were take from each foal within 2 - 3 days after their birth: the height at withers, circumference of chest and cannon bone. The foals were systematised according to their mothers' age. The numerical data was worked out by means of basic statistical calculations.
Results of researches. In table 1 is presented the relation between the number of foals and the mare's age during foaling.
Table 1
mare's age number of foals length of the intergestation period [days]
up to 5 years 56 23% 117,22
up to 10 years 157 64% 129,71
up to 15 years 30 12% 109,79
over 15 years 2 1% 89,5
The shortest intergestation period, which was on average 89,5 days, was characteristic to the oldest mares, whereas the mares not older than 10 years had 129,7-day-long intergestation period.
In table 2 is presented the outcome of measurement of foals' height at withers, with regad to the length of the intergestation period.
Table 2
length of the intergestation period number of foals [n] Average [cm] SD
A: up to 14 days 56 98,09 3,19
B: up to 40 days 86 98,53 3,64
C: up to 65 days 56 99,11 2,96
D: up to 365 days 40 98,60 3,59
E: over 365 days 8 99,37 2,20
The obtained results allow to conclude that among all the foals, the highest average height at withers (99,37 cm) was measured among those born after the intergestation period lasting over 365 days. The lowest average height at withers (98,09 cm) was recorded among the foals born after the intergestation period lasting not more than 14 days. According to Brzeski et al. (1982) the average height at withers of Trakehner sucklings was 100-110 cm. Among the foals of thoroughbred breed this size was 140 cm (Tokarska 1996). The analysis did not reveal any crucial differences in the investigated relation.
In table 3 the length of intergestation period was compared to the foals' chest circumference.
Table 3
length of the intergestation period number of foals [n] Average [cm] SD
A: up to 14 days 56 82,34 3,65
B: up to 40 days 86 83,17a 3,80
C: up to 65 days 56 83,44b 3,14
D: up to 365 days 40 81,72abc 3,59
E: over 365 days 8 84,75c 2,55
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Averages marked with the same small letters differ significantly P<0,05
The obtained results allow to conclude that among all the foals, the highest average value of the parameter (84,75 cm) was measured among the ones born after the intergestation period lasting over 365 days. The lowest average chest circumference (81,72 cm) was recorded among the foals born after the intergestation period lasting not more than 365 days. It was demonstrated that the foals born after the intergestation period lasting from 65 to 365 days, and which after birth had the lowest average chest circumference, statistically differed to a great extent from the foals born after the intergestation period lasting from 40 to 65 days and more than 365 days. The thoroughbred foals had the average chest circumference of 150,41 cm (Tokarska 1996), which was a lot more than in case of purebred Arabian foals.
Table 4 shows the influence of the length of the intergestation period on the foals' cannon circumference.
Table 4
length of the intergestation period number of foals [n] average [cm] SD
A: up to 14 days 56 10,78aB 0,46
B: up to 40 days 86 10,98a 0,56
C: up to 65 days 56 11,05B 0,55
D: up to 365 days 40 10,95 0,60
E: over 365 days 8 11,10 0,70
Averages marked with the same capital letters differ highly significantly P<0,01
Averages marked with the same small letters differ significantly P<0,05
The achieved results show that the foals born after the intergestation period lasting more than 365 days had the greatest average value (11,10 cm), whereas the foals born after the intergestation period lasting up to 14 days had the lowest average value of the parameter (10,78 cm). It was also shown that the length of the intergestation period had a statistically important influence on the circumference of cannon bone among the foals born after the intergestation period lasting up to 14 days and the ones born after the intergestation period lasting up to 40 days, as well as statistically considerable influence on the foals born after the intergestation period lasting up to 14 days and the ones born after the intergestation period lasting up to 65 days. The circumference of cannon bone (12,5 cm) of Trakehner horses after birth (Brzeski et al. 1982) was close to the result obtained in the described research, but Tokarska (1996) states that the average value of cannon circumference of thoroughbred foals was 17,49 cm that is a lot more than the result of the described research.
Conclusions. The length of the intergestation period depended on the mare's age. The shortest was among 5-year-old mares, the longest among 10-year-olds. The length of the intergestation period was statistically important to the circumference of chest and cannon bone, but had no influence on the height at withers. All the three parameters of the foals born after the intergestation period longer than 365 days were the highest.
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Reference
1. Bielanski A., Tischner M. 2000, Biotechnologia rozrodu zwierz^t udomowionych, Drukrol, Kraków
2. Brzeski E., Kulisa M., 1982, Charakterystyka biometryczna koni czystej krwi arabskiej. Zesz. Probl. Post. Nauk Roln., 264, 567-572
3. Kuznik A., 2003, Próba okreslenia wpfywu masy ciala zrebiqt czystej krwi arabskiej po urodzeniu na pózniejszy ich rozwój i karier^ wyscigow^, maszynopis, UR Kraków
4. Tokarska M., 1996, Analiza wzrostu i rozwoju zrebiat pelnej krwi angielskiej z SK Jaroszówka, Przegl^d Hodowlany, nr 6, 11-15
5. Zwolinski J., 1980, Hodowla koni, PWRiL, Warszawa
Summary
Celem niniejszej pracy bylo zbadanie wpfywu dfugosci okresu mi^dzyciqzowego na parametry biometryczne zrebiqt wykonane po urodzeniu. Materiaf do badan zebrano w 2005 roku w panstwowej stadninie koni czystej krwi arabskiej. Zebrane dane dotyczyfy 75 klaczy stadnych i 245 zrebiqt, obejmujq lata 1980 do 2005. Dla kazdej klaczy obliczono dfugosc okresu mi^dzyciqzowego. Kazdemu zrebakowi w okresie 2-3 dni po urodzeniu zmierzono nastqpujqce parametry biometryczne: wysokosc w kfqbie, obwód klatki piersiowej oraz obwód nadp^cia. Dfugosc okresu mi^dzyciqzowego byfa uzalezniona od wieku klaczy. Najkrótszy wystqpif u klaczy 5-letnich, a najdfuzszy u 10-letnich. Czas trwania okresu mi^dzyciqzowego wpfynqf statystycznie istotnie na obwód klatki piersiowej oraz obwód nadp^cia, natomiast nie znaleziono takiej zaleznosci dla pomiaru wysokosci w kfqbie. Zrebi^ta urodzone po okresie mi^dzyciqzowym trwajqcym powyzej 365 dni miafy najwi^ksze wszystkie trzy pomiary biometryczne - wysokosc w kfqbie, obwód klatki piersiowej i obwód nadp^cia.
Cmammx nadiümna do peda^ii 3.04.2009
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