REPRODUCTION OF CHINCHILLA (CHINCHILLA LANIGER M.) ON THE EXAMPLE OF SELECTED POLISH BREEDING FARM Danuta Dzierżanowska-Góryń, Robert Głogowski Warsaw University of Life Sciences, Warsaw, Poland (Поступила в редакцию 04.06.2010 г.) Summary. The reproduction results of chinchilla females were describer in 10 years period of selected farm of activity. These results were improved during selection. The analysis of seasonal charter of reproduction was negative. In almost every months the pups were born, with various intensity. Chinchillas are polyestrous, reaching the sexual maturity in the age of 6 months. Long pregnancy lasting up to 111 days and small litters cause that breeders are aspiring to get on average two births per year from the female. Good results in the husbandry depend above all on good results of the reproduction. The size of litters on chinchilla farms is still diversified. According to literature, the number of progeny in the litter varies from 1 for 6 (Barabasz 2001). Polyestrous reproduction of chinchilla has the seasonal character (Sulik et al. 2001). The escalation and the course of reproductive functions depends on environmental conditions that are maintained on the farm. At the wild living animals the length and the seasonal character of cycles is corresponds to the best climate and dietary conditions, so pups are born in optimal moment. The intensive reproduction period for chinchilla, in natural conditions of the mountain climate of the Andes, is falling on time between April and September, what in European conditions complies to the period from the early spring till the summer (Gromadzka-Ostrowska 1998). A few reports of analyses of the seasonal character in the reproduction chinchilla in Poland were published, however an unequivocal answer is missing if over 100 years of the chinchilla breeding influenced reducing seasonal character in births in certain periods of the year. This work is aimed at evaluation of chinchilla birth results on the selected farm and the annual pattern of births. Material and methods. Studies were carried out on the reproduction chinchilla farm located in central Poland. The farm was established in 1996 on the basis of 4 families. The farm became embraced by the assessment of functional value when the number of females of the basic herd counted 60 females (1999). The farm specializes in breeding of the chinchilla of the variety standard, but also different varieties are black velvet, beige Polish, white of Wilson and purple. Animals are being held in two rooms on approximate surface respectively: 54 and 20 m2, well lighted and ventilated. In the autumn-winter period rooms are additionally illuminated. Chinchillas are kept in cages for the polygamous breeding placed on four levels. 4 females and one male form the polygamous set. Females are staying one by one in connected cages with shared corridor in whom the male is staying. He has the free access to every female, however females have a collar put on to the neck preventing them from leaving the cage. At first animals were held in the system with bedding, with moved drawers, however from 2005 animals are being held in the less laborious system without bedding. An equipment of the cage is automatic feeder, the dust bath tub and the teeth wiping stones. Animals are being fed pellets with hay and additional feed once during the week. Herbs, cereals and rosehips constitute this fodder. Results and discussion. Table 1 presents basic indicators of the reproduction of females on the farm from its establish in 1997. During these years, indices improved, with slightly increased basic herd size. It can be stated that the breeder with growing experience, achieves more and more good results. The total number of progeny increased in every year. In 1997, 90 pups were born from 60 females, and 74 were weaned, which constitutes 82%. However in 2000, 89 pups were weaned (53%), and in 2006 the percentage of weaned pups was 95,26%. The share of deaths till weaning developed on level 4,74 to 17,78%. Different authors report mortality rate from 10,4 to 22,6% (Felska et.al. 2002; Sulik and Barabasz 1995). Two first analyzed years were the worst, when level of weaning developed on the level 82%. It is possible to explain it with the fact that animals were purchased and the breeder didn't have the possibility of choosing females for their reproductive value. In consecutive years, when the improvement in these indicators took place these speculations were confirmed. In consecutive years the number of litters grew on the farm and a percent of young chinchillas also grew up. Along with the growth in the number of litters, and consequently decreasing number of infertile females a fertility of the herd grew and a mortality of young animals was reduced. Seremak and Sulik (2003) got the similar results in their examinations. They observed the average mortality of 19%, with the highest value rate 25,1% in the year with the low number of litters on the farm. In the year 2002, 4,08 pups per female were born with 3,53 pups weaned. The following years shown a slight decrease of the number born pups per female, however number of weaned pups stayed at the level over 3, what constitutes satisfactory result. These are higher values than those reported by Sulik and Barabasz (1995). They noted the fertility of the herd as 2,4 pups born and 2,09 weaned from the female per year. However different authors for imported females from the Denmark got 3,46 pups born and 3,05 pups weaned from the female per year (Felska and Brzozowski 2001). The size of the litter at birth is an essential parameter which influences the annual reproduction results on the farm. High average values were obtained in presented study. During last decade it was developed on the level of 1,76 to 2,13. It can be considered satisfying, they do not differ from the data published in literature from different farms. Similar value: 1,98 medium size of the litter was reported by Seremak and Sulik (2003). In different studies 1,81 to 2,36 litter size at birth was reported (Socha and Wrona 2000). This parameter is essential, it influences annual results of the reproduction on the farm. Potential reproduction abilities of chinchilla females are high, Jarosz and Rżewska (1996) report 4 pups born in the litter. In the estrous phase, about 4 Graafian follicles develop, so in optimal conditions the size of the litter should be 4 pups. 1 Table 1 – The reproduction results of chinchilla females (1997-2006) Number of females Number of born pups Number of weaned pups % of weaned pups Average litter size born Pups per female weaned Number of litters Number of litters from female per year 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 60 60 60 60 60 60 60 72 72 72 90 167 211 191 230 245 219 271 268 232 74 137 181 171 191 212 202 256 246 221 82,22 82,04 85,78 89,53 83,04 86,53 92,24 94,46 91,79 95,26 1,76 1,88 1,95 1,84 2,13 2,01 2,01 2,04 1,93 1,90 1,50 2,78 3,52 3,18 3,83 4,08 3,65 3,76 3,72 3,22 1,23 2,28 3,02 2,85 3,18 3,53 3,37 3,56 3,42 3,06 51 89 108 104 108 122 109 133 139 122 0,85 1,48 1,8 1,73 1,8 2,03 1,82 1,85 1,93 1,69 The number of litters from female during the year grew from 0,85 in 1997 to 2,03 in 2002. This value is the highest on this farm and higher than reported by different authors. Sulik and Barabasz (1995) mentioned 1,5 litter per year, Felska and Brzozowski (2001) 1,59 for imported chinchilla. Barabasz et al. (2000) however got 1,54 to 1,9 litters per year on examined farms. The result of 2 litters from the female per the year is a very beneficial and in accordance with the natural annual rhythm of animals. Long pregnancy, the low fertility and getting the low amount of litters from females of the basic herd is result in low profitability of breeding of this species. However, three births per year can lead to excessive exhaust of the organism of the female and shortening the period of reproduction activity. The second studied aspect was the seasonal pattern of births in chinchilla. Data presented in table 2 concern the monthly percentage distribution of births during 5 years, from 2002 till 2006. Analyzing above value it should be stated that in all the births took place in all months, however it is possible to observe tendencies in increasing of the births numbers in individual months. The lowest number of births were noted in January (all breeding seasons) and December. The most of births were observed in March/April and July/August. Also the large number of births was observed in October 2003 and in September 2005. So the pattern of seasonal reproduction activity of chinchilla is hard to describe. This conclusion is similar to results of Sulik (2002). According to the Jarosz and Rżewska (1996) the period of the increased sexual activity in polish climate lasts from November till May, with the greatest intensity in January and February. It was also observed, that chinchilla reared in heated rooms during winter had been characterized by a distinct seasonal character in the reproduction. However females held in the fixed temperature reproduced all through the year. However Gromadzka-Ostrowska (1998) stated that the reproductive season lasted in Poland from November till April with the top intensity in March. Taking into consideration 111 days of pregnancy, the period of intense births lasts from March till August. Table 2 – The percentage of chinchilla litters in consecutive years Month January February March April May June July August September October November December 2002 4,92 7,38 18,03 7,38 6,56 10,66 12,3 5,74 7,38 6,56 8,2 4,92 2003 4,59 8,26 11,93 13,76 8,26 6,42 5,5 6,42 8,26 13,76 7,34 5,5 2004 2,26 7,52 6,77 12,78 10,53 9,02 10,53 9,77 9,02 2,26 9,77 9,77 2005 6,47 2,88 5,76 9,35 12,95 7,19 6,47 16,55 10,07 7,91 8,63 5,76 2006 4,1 2,46 13,93 12,3 8,2 7,38 13,93 6,56 9,84 4,92 9,02 7,38 Jarosz et al. (1996) claim that from May till October, the frequency of estrous phases is much lower and its manifestations are poorly emphasized. It is the natural period of the lower reproduction activity. If a female doesn't get pregnant between November and May, it is a probability of another mating in the given year is low. On American farms the results from observation, that after the second birth in July and August it is possible to mate 20% of females. So the possibility of getting the third litter in the year is small, and due to exhausting the female’s organism, also inadvisable. Conclusions. Relatively high values of reproduction indices in chinchilla females in consecutive years on the analyzed farm, may indicate the correct husbandry at the farm. 2 Currently published results of the studies along with presented in this paper, allow for the conclusion that the leveled climate conditions during the year may result in ceasing of the seasonal character of chinchilla reproduction. LITERATURE 1. Barabasz B., 2001 – Szynszyle. Hodowla i użytkowanie. PWRiL. Warszawa 2. Sulik M., Seremak B., Bielińska A., Mieleńczuk G., 2001- Intensywność użytkowania rozpłodowego samic szynszyli na wybranej fermie na Pomorzu Zachodnim. Zeszyty Naukowe Przeglądu Hodowlanego, 58,73-80 3. Gromadzka-Ostrowska J., 1998- Studia nad fizjologią szynszyli ze szczególnym uwzględnieniem rozrodu i odporności. AR Kraków, zeszyt 238. Rozprawa 4. Felska L., Brzozowski M., Rzewuska E., 2002; - Wyniki rozrodu szynszyli w zależności od poziomu ustawienia klatek i nateżenia światła. Zeszyty Naukowe Przeglądu Hodowlanego, 64, 97-102. 5. Sulik M., Barabasz B., 1995- Porównanie systemów utrzymania rozpłodowego na przykładzie wybranych ferm. Zeszyty Naukowe AR w Krakowie 297, 159-165. 6. Seremak B., Sulik M., 2002a- Sezonowa aktywność rozrodcza samic szynszyli na wybranych fermach. Zeszyty Naukowe Przeglądu Hodowlanego, 64, 89-96. 7. Seremak B., Sulik M., 2002- charakterystyka wskaźników użytkowania rozrodczego szynszyli na przykładzie wybranej fermy 1997-2000. ACTA Scientiarum Polonorum, Zootechnica, 1 (1-2), 139-146. 8. Seremak B., SulikM., 2003- An attempt to determine causes of lowered values of breeding indices on a chinchilla farm. Scientifur, 26(3),75-78. 9. Socha S., Wrona A., 2000- The analysis of the seasonal character of the chinchilla (Chinchilla velligera M.) reproduction. Scientifur, 24(4), 4952. 10. Jarosz S., Rżewska E., 1996- Szynszyle, Chów i hodowla. PWRiL. Warszawa 3