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Niedbala Piotr, Warecki Dariusz, Szeleszczuk Olga ©
Agricultural University, Krakow, Poland
THE AGE STRUCTURE AND RESULTS OF REPRODUCTION OF BREEDING RACOON DOG MALES ON SELECTED FARMS
The available scientific literature regarding racoon dogs' reproduction bring up a couple of problems regarding fertility and fecundity of females, a system of cover or evaluation of breeders based on semen quality. There is a lack of precise information about reproduction possibilities of racoon dogs' males depending on the length of utilization. The aim of this study was evaluation the age of breeders on: sexual activity, number of copulations and their effectiveness or number of born and weaned progeny. The analysis showed that the most active are males in a second reproduction season, but the highest values of investigated parameters were characteristic however for experienced 4-year old males.
Key words: raccoon dog, male reproduction, age structure
Introduction. The fur animal breeding in Poland is based on minks, ordinary foxes. The marginal her part is ferret breeding, much larger arctic foxes and racoon dog. Somatic maturation racoon dogs achieve in seventh month of life, and by next three are ready for reproduction. These abilities keep even by dozen or so years (Kuzniewicz, Filistowicz, 1999). In natural conditions racoon dog is a monogamists, in farm conditions is kept in polygamy.
The sexual activity of males can be high, but the activity period can be short. Lorek (1980) underline, that very active males can complete even 61 covers during one reproduction season. The factors significantly influencing on their reproductive value is many. To the most important belong proper feeding, proper hygiene conditions, and veterinary prophylaxis. The considerable factor influencing is a proper animal conditioning before copulation season. Alike in natural and in farm conditions, they have a great ability of hypodermic fat accumulation as a storage material (Cholewa, 1988).
About intensity of reproductive utilization of racoon dog males to some degree decide cover system used on the farm. It can be twice time cover, recommended by Russian breeders (Ilina , 1952). The most common is three times cover of females recommended by Zon et al. (1989).
In the literature domestic and foreign alike, are articles presenting mainly about reproduction utilization of racoon dog females, their fertility and fecundity, the number of born and weaned pups. There is a lack of elaborations discussing obtained results of reproduction depending on the age of males. The only accessible information is article by Gawarecki and Barabasz (1982), which is the analysis of reproduction data of fresh imported racoon dogs from Finland. It is interesting and need to be checked how at present is reproductive potential of breeding male racoon dogs' on some farms.
© Niedbala Piotr, Warecki Dariusz, Szeleszczuk Olga, 2008
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The aim. The aim of this study was definition of intensity of reproductive utilization of racoon dogs' males on selected Polish farms. Definition the influence of breeders' age on: sexual activity, the number of born and weaned pedigree, also recalculated on copulations and day of sexual activity.
Material and methods. The investigations were carried out on two breeding racoon dog farms on south-eastern Poland. On both farms animals were kept in pavilion system and fed using farm fodder. During the all period when animals were investigated, males were in a good physical condition and good health. Through proper conditioning there were also properly prepared to reproduction season.
The analysis was conducted based on results from 1998 - 2004 on the first farm where 35 males was evaluated, which covered 166 females. On the second farm 129 males was evaluated, which covered 952 females. Because on practice and own study (Niedbala, 2003), similar like in other canines it resulted that the quality of first ejaculates is very low (in majority they contain dead or damaged and not moving spermatozoa) so first cover of each male is considered non effective.
The indicators of male racoon dog reproduction utilization were calculated based on data from breeding documents and farm notes. Males of basic flock were divided into five age groups: one year old males, two years three years, four years and older. Within the group there were analysed: the length of sexual activity, number of completed copulations, effectiveness of cover, number of born and weaned pedigree. Obtained results were analysed statistically. Results were presented in form of graphs and means.
Results of researches. The sexual activity males present only when females are in heat i.e. from the end of January till March (Jarosz, 1993). After this period they do not express concern about females. Essentially is that during covers the breeder should always administer the active and checked males. It needs to be underline, that the choice of a new males on breeders is done mainly on the base of fur quality but not reproductive. The first copulation season gave the answer to the breeder on the correctness of his choice.
All books information among other Kuzniewicz and Filistowicz (1999) informed that the length of utilization period of male racoon dogs' should not exceed 6 - 7 years. On both farms, the maximum length of this period was 5 years. The majority of males on Farm A were utilized 3 and 4 years, while the age structure of males on Farm B was shifted toward young males, which compose over 40% of total breeders. Such situation resulted from annual increase of female headage of base flock (Table 1).
The results achieved by racoon dog males in respective reproduction seasons present a big fluctuation. Looking for the length of sexual activity, the best were males in the third copulation season presenting sexual drive through 20.76 days (Figure 1). Somewhat weaker were males younger by one year. These results clearly differ from those presented by Frindt (1996), which claim, that males are active only through a couple days during season.
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Table 1.
The age structure of raccoon dog ^ males.
Period of utilization Farm A Farm B
N^ = 35 % N^ = 129 %
5 - years 2 5,71 3 2,33
4 - years 9 25,71 9 6,98
3 - years 9 25,71 20 15,50
2 - years 7 20,00 45 34,88
1 - year 8 22,87 52 40,31
Figure 1.
Reproductive activity acording to the age of males.
u
s
c
£
Q
25 20 15 10 5 0
19,73 20,76
14,7
9,01
11,81
1714
11,31
13,4
10,42
7X
1 2 3 4 5
Duration of utilization (years).
□ Activity □ Copulations
But there are similar to those published by Gawarecki and Barabasz (1982), who presented that young males born in the country (after imported animals) are active the shorter , at least through three weeks. It need to be focused, that the changes of length activity accompany similar increase of completed copulations, only with difference that their number increase to the second season (11.85). Next it gradually decreases reaching 7.8 copulations in oldest animals. A similar value of this trait was observed also by Gawarecki and Barabasz (1982). They published, that males in the second season may complete 11.41 jumps. This activity, as presented in own investigations did not have reflection in the case of ordinary foxes, the species belonging to the
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same family, canines. Socha and Jezewska (2000) presented, that the number of foxes females covered, increase proportionally to the age of males, reaching the top for five years old breeders. The number of females covered is directly proportional to the number of completed copulations. Quite different according to this authors behave imported males, which in the first year covered 4 females, in a second 6, but in the fifth season only 4.6.
While two former parameters changed similarly, the effectiveness of copulation showed the lowest fluctuations and had different tendency. From effectiveness at the level 81.9% in the first year of utilization, through 79% in a second year, to the lower in the third season 77.3% was observed. In the fourth year the increase value of this coefficient to the highest in oldest males 92.3% was observed.
As it could be assumed the lowest number of pups born and weaned per one male was characteristic for the group of new breeders turned on to the base flock, from which they got over 14 neonates (Fig. 2) and weaned only 10.63 individuals.
Figure 2.
Born and weaned pups acording to the age of males.
25 20 15
20,44
Цн
<u
в
I io-H
5 0
14,11
2 3 4
Duration of utilization (years)
□ Born □ Weaned
Similar dependence was observed with ordinary foxes (Socha and Jezewska, 2000). The highest number of cubs born and weaned was obtained from four year old respectively: 20, 44 and 18 individuals. The age group in case of ordinary foxes, from who can be obtained the most weaned cubs, are animals in the third year of utilization and the oldest males. When calculating on statistical copulation, the most pups were obtained after oldest males (Fig.3). The numbers of obtained
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Figure 3.
Born and weaned pups par for the copulation acording to the
age of males.
2,5 -
2 --
r e 1,5 --
B
1 --
0,5 --
0 --
1,96
1,57 1,57 1,68
1,18
1,18
1,3
2 3 4
Duration of utilization (year)
□ Born □ Weaned
pups increase gradually from 1.57 in the first and in a second year of utilization, to 2.15 in the fifth season. But it was unsuccessful in this age group to get quite high number of weaned animals. It was the highest with four years old males. It need to be emphasise that after each season, breeders have possibility to gain so call postcopulation pelts what is associated with reduction from breeding males which unfortunately did not prove correct. So to the next year will stay only the best males. There is a need to attend the higher presence of them within the group of breeders. But the coefficient of remodelling allow for 20 - 25% presence in a flock, as it is on Farm A. The settlements of the female flock on the certain level on Farm B bring to increase values of discussed parameters.
It was observed reverse dependence: the longer activity and more completed jumps, the lower number of pups born per one day of activity is smaller (Figure 4). The lowest number of pups was obtained when males were active the longer (0.92 individuals). Whereas 4 year old males were the group of animals, which gave over 1 individual weaned from one day of activity.
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Figure 4.
Born and weaned pups for the day of activity acording to the age of
males.
1,4 1,2 ^ 1
n 0,8
I °,6
0,4
0,2-H 0
0,96
0,95
0,92
0,72
0,71
0,71
1,19
1,05
1,25
2 3 4
Duration of utilization (year)
0,89
□ Born □ Weaned
Conclusions. Because of to short activity of five years old males, small number of completed copulations and large percentage of dead pups from the birth to the weaning, the length of reproduction utilization of racoon dog males should not exceed four years.
Reference
1. Cholewa R. 1988. Chow i hodowla lisow. Panstwowe Wydawnictwo Rolnicze i Lesne, Warszawa.
2. Frindt A. 1996. Chow jenotow. SGGW Warszawa.
3. Gawarecki J., Barabasz B. 1982. Wyniki rozrodu jenotow na fermie w Wiartlu. Hodowca Drobnego Inwentarza, 30, 9, 13-15.
4. Ilina E.D. 1952. Zwierowodztwo, Moskwa.
5. Jarosz S. 1993. Hodowla zwierz^t futerkowych. Panstwowe Wydawnictwo Naukowe, Warszawa.
6. Kuzniewicz J., Flistowicz A. 1999. Chow i hodowla zwierz^t futerkowych.. Wydawnictwo Akademii Rolniczej we Wroclawiu.
7. Lorek O. 1980. Sprawozdanie z odbytej praktyki na fermie jenotow w Finlandii, w czasie od 15.02. do 30.03 1980. Ministerstwo Rolnictwa -Departament Produkcji Zwierzçcej.
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8. Niedbal^ P. 2003. Wlasciwosci biologiczne i biochemiczne oraz przydatnosc do mrozenia nasienia jenotow hodowlanych (Nyctereutes procyonoides Gray). Maszynopis AR Krakow.
9. Socha S., Jezewska G. 2000. Wykorzystanie rozplodowe samcow lisow pospolitych (Vulpes vulpes L.) w zaleznosci od wieku i pochodzenia. Zeszyty Naukowe PTZ 53, 105 - 113.
10. Zon A., Bielanski P., Niedzwiadek S. 1989. Study of the system of mating raccoon dogs. Scientifur, 13, 2, 141-144.
Summary
In the domestic and foreign literature there is a lack of precise elaborations regarding reproduction of racoon dog males: the length of sexual activity, the number of completed copulations, their effectiveness, and the number of born and weaned progeny depends of the male age. The aim of this paper was analysis of these parameters on selected Polish farms.
The investigations were carried out based on results from 1989 - 2004. In reproduction attended 164 males which covered a total of 1118 females. The calculation of respective indicators of reproductive utilization for: one, two, three, four and five year's old males were done based on breeding documentation and farms' notes.
The least group completed the oldest males was observed on farm I (5.71%), where dominate males utilized for 3 and 4 years. Quit different was the age structure of breeders on a second farm, where gradually decrease of presence of older males was observed from 40.31% to 2.33% within five years. When considered the length of sexual activity, the males from respective groups were active from 2 to 3 weeks, and the longer active were males in third and second year of utilization. The most intensive covering, were two years males. But the most experienced four years old males had the highest, because over 80% effectiveness of cover. One with the most important indicators of reproductive utilization of males of all animal species is number of born pedigree. The best were four year's old males with result 20.44. Similar to that group weaned 18 pups. The analysis of obtained results show clearly that from five year's old males we can get the most pups from one copulation, as well as from one day of activity. Because of their small number (3%), in a small degree they influence on the number of born pups. The best results regarding the number of weaned pups from one copulation, and one day of activity, it turned to males in fourth season of utilization. So we can affirm, that because of short activity of five year's males, small number of completed copulations and large percentage of dead pups before weaning, the length of reproductive utilization racoon dog males should not exceed four years.
Cmammx nadiuMna do peda^i'i 9.04.2008
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