Animal Science Papers and Reports vol. 24 (2006) Supplement 1, 87-91 Institute of Genetics and Animal Breeding, Jastrzębiec, Poland Presented at the Conference Genetic and Breeding Research on Pigs with Special Reference to Indigenous Breeds organized to commemorate the 10 th anniversary of the death of Professor Stefan Alexandrowicz 20-21 October 2005, Poznań, Poland The effect of the season of farrowing on selected performance traits in Pulawska sows Andrzej Stasiak, Anna Kasprzyk, Małgorzata Sałyga Departament of Pig Breeding and Production Technology, Agricultural University of Lublin, Akademicka 13, 20-950 Lublin, Poland Reproductive performance was analysed in 91 Pulawska sows and their 409 litters in relation to the season of the year in which they farrowed. An analysis included the data recorded over five years (1999-2004). In winter and autumn the fertility was higher than in spring season. Identified was the effect of season on the age of first farrowing and length of weaning to fertile mating period. In summer the length of dry period was significantly higher than in remaining seasons. KEY WORDS: sows / reproductive performance / season Although the reproductive ability of the Sus scrofa domestica in comparison to other species of livestock is enormous, it is not fully exploited. Sow utilization is influenced by genetic and environmental factors. The low heritability of reproductive traits shows the role of environment in shaping the feature, the most important factors being feeding, handling, the microclimate, the herd s concentration and the organization of production. Among other, less important factor influencing reproduction is the season the sow or litter were delivered [Grudniewska et al. 1978, Ruda i Waligóra 1987, Kapłon i Różycki 1989, Dyrcz 1990, Kasprzyk 2005]. 87
A. Stasiak et al. Available references contain no definite information on the effect of the sows farrowing season on their reproductive performance. This is why this report deals with the subject at hand. Material and methods Used were records available from Experimental Farm, Czesławice, for the years 1999-2004, concerning 91 Pulawska sows as well as their 409 litters. According to the season of farrowing the sows were divided into four groups: farrowing in winter (months XII, I, II), in spring (III, IV, V), in summer (VI, VII, VIII) and in autumn (months IX, X, XI). The following factors were analysed: litter size born (number of live born piglets), litter size on day 21, sow age at first farrowing, farrowing interval, and weaning-fertile mating interval. The data were evaluated statistically using the SPSS/PC computer programme with the one-way analysis of variance (Duncan test) and significance of differences between s identified at the level of 0.05 and 0.01. 88 Results and discussion Litter size born (Tab. 1). The number of live piglets born was 11.1 appearing lower than in commercial productive herds of maternal Polish Large White and Polish Landrace breeds in the years 1999-2004 (11.55-11.59 respectively) Orzechowska and Mucha [2002]. Litter size depends on the mating period and time, sow feeding, first farrowing age and farrowing parity. Higher live-born piglet number was observed in autumn/winter than in spring/summer seasons (by 0.3 and 0.1, respectively), significant differences (P 0.05) being identified between the winter and spring seasons). The results showed in this report are in accordance with the opinion presented by Dyrcz [1990], who indicated that most of piglets are born between January and March, whereas the summer season affects the sow s fertility negatively. Lorvlec et al. [1996] in their analysis of Large White pig reproductive performance in France concluded that litter size in summer decreased by till 25%. On the other hand Grudniewska et al. [1978] stated that the best seasons for obtaining high fertility in sows are February- April and August-October. Litter size on day 21 (Tab. 1). This is the most important feature in economic terms when stating an animal s reproductive value and also the basic indicator of production profitability [Kasprzyk 2005, Ruda i Waligóra 1987]. In a group of sows studied (Tab. 1) a value of 10.9 piglets was comparable to the Polish Large White sows in domestic herds being monitored at the same period of time [Orzechowska and Mucha 2002]. Means presented for litter size on day 21 varied in a narrow range. However, significant differences (P 0.05) were identified between the winter and spring seasons. According to Kasprzyk [2005] better results in raising piglets were obtained by Polish Landrace sows farrowing in the winter and spring season.
Genetic and Breeding Research on Pigs with Special Reference to Indigenous Breeds Table 1. Selected reproductive traits of Pulawska sows as affected by seasons of the year Trait Season winter spring summer autumn Litter size born Litter size on day 21 Age at first farrowing (days) Farrowing interval (days) Weaning-fertile mating interval (days) 11.2 a 1.02 11.1 a 1.02 344.1 B 35.6 184.5 14.6 18.0 7.0 10.9 b 0.78 10.8 b 0.80 353.5 43.2 172.9 A 17.9 6.87 B 14.0 11.1 0.96 10.9 0.95 357.5 A 51.7 188.3 B 15.4 22.28 A 23.00 11.2 0.92 11.0 0.94 335.5 C 45.4 176.5 11.5 10.48 B 16.0 aa... Within rows s bearing different superscripts differ significantly at: small letters P 0.05; capitals P 0.01. Age at first farrowing (Tab. 1). Mean first farrowing age was 349 days, comparable to respective values reported for remaining pig breeds maintained in Poland [Orzechowska i Mucha 2002]. Significant differences were identified between seasons. The oldest sows (at the age of 357.5 days) farrowed within the summer season (months VI, VII, VIII). Some authors agree in that the fall of reproduction performance of sows during the summer months is related to the unfavorable microclimate in the piggery [Ruda i Waligóra 1987, Kapłon i Różycki 1989]. Another general opinion is that fluctuation in the reproduction performance is connected with the changes in accessible light during daytime [Liminowicz 1982, Dyrcz 1990]. Farrowing interval (Tab. 1). The longest farrowing interval was noted in sows farrowing in the summer season while the shortest for those farrowing in the spring season (188.3 and 172.9 days, respectively, P 0.05). Liminowicz [1982] working on the seasonality of sow reproduction stated that the summer months are exceptionally difficult due to the low conception rate. The reason for the extended farrowing interval between consecutive farrowings observed in summer months, Kapłon and Różycki [1989] explained to be a result of prolonged rest periods, affected in turn, by oestrus disorders [Liminowicz 1982]. The length of the reproduction cycle has a significant effect on farrowing frequency. The analysed sow population had a farrowing interval of 180.5 days. The farrowing frequency in this population (2.01 litters per year figures non tabulated) was at a level similar to that found for the Polish Large White and Polish Landrace performance-tested sows [Orzechowska i Mucha 2002]. 89
A. Stasiak et al. Weaning-fertile mating interval (Tab. 1) An underestimated by many breeders reason for decreased herd fertility is the relatively long farrowing interval due to the time spent for lactation and resting, that reduces the farrowing frequency [Ruda i Waligóra 1987]. In the present report the sows showed a significantly (P 0.01) longer weaningfertile mating interval (rest period) 22.28 days in the summer than in the spring (6.87 days) and autumn seasons (10.48 days). It generally confirms the earlier observations by English et al. [1977], Kapłon and Różycki [1989], Falkowski and Groszkowska [1994], and Batorska et al. (2004) showing that during long summer days and high summer temperatures sexual activity of sows decreases, manifesting itself by so called silent heat and irregular sexual cycles. In consequence, an extension of sow s nonproductive period is observed. It can be concluded that sow s fertility was by 0.3 piglets higher in autumn/ winter than in spring season. Significant differences in the age of first farrowing were identified between seasons. The longest farrowing interval was shown in sows farrowing in summer season, while in those farrowing during the spring it was by about 15 days shorter. In the population of Pulawska sows the relation was shown between the farrowing season and length of weaning-fertile mating interval. In sows farrowing in the summer season the weaning-fertile mating interval was significantly longer than in those farrowing in remaining seasons. 1. 2. 3. 4. 5. 6. 7. 8. 9. REFERENCES BATORSKA M., REKIEL A., WIĘCEK J., 2004 Wpływ genotypu ojca i sezonu na wybrane cechy rozrodu w stadzie świń. Zeszyty Naukowe Przeglądu Hodowlanego 2, 59-67. DYRCZ S., 1990 Badania nad wpływem sezonu na wielkość cech użytkowości rozpłodowej loszek i loch rasy wbp. Roczniki Naukowe Zootechniki 1, 18-19. ENGLISH P.R., SMITH W.J., MACLEAN A., 1977 The sow improving her efficiency. Farming Press Limited. FALKOWSKI J., GROSZKOWSKA A., 1994 Obserwacje nad wpływem kolejnego oproszenia, sezonu i liczby prosiąt odsadzonych w miocie na długość jałowienia loch. Acta Academiae Agriculturae Ac Technicae Olsteniensis, Zootechnika 40, 55-61. GRUDNIEWSKA B., FALKOWSKI J., ZALEWSKI H., 1978 Wpływ kolejności oprosień, sezonu i roku kalendarzowego na niektóre cechy użytkowości rozpłodowej loch rasy wbp. Zeszyty Naukowe ART w Olsztynie, Zootechnika 17, 87-99. KAPŁON M., RÓŻYCKI M., 1989 Wpływ sezonu na niektóre cechy użytkowości rozpłodowej loch. Roczniki Naukowe Zootechniki, Monografie 26, 237-249. KASPRZYK A., 2005 Wpływ kolejności oprosień i sezonu na wybrane wskaźniki użytkowości rozpłodowej loch rasy pbz. Annales Universitatis Mariae Curie-Skłodowska, sectio EE, Zootechnika (in press). LIMINOWICZ J., 1982 Badania nad sezonowością rozrodu loch w fermie przemysłowej tuczu świń w Knopinie. Przegląd Hodowlany 12, 28-29. LORVLEC O., DEPRES E., RINALDO D., CHRISTON R., 1996 Effect of season on reproductive performance of Large White pig in intensive breeding in the tropics. Journees de la Recherche Porcine en France 28, 276-287. 90
Genetic and Breeding Research on Pigs with Special Reference to Indigenous Breeds 10. 11. ORZECHOWSKA B., MUCHA A., 2002 Ocena użytkowości rozpłodowej loch. Stan hodowli i wyniki oceny świń. IZ Kraków, 13-33. RUDA M., WALIGÓRA J., 1987 Wpływ sezonu urodzenia i oprosienia na wartość rozpłodową loch rasy wbp użytkowanych w terenie górzystym. Trzoda Chlewna 10, 4-7. Andrzej Stasiak, Anna Kasprzyk, Małgorzata Sałyga Wskaźniki rozpłodu loch rasy puławskiej zależnie od sezonu oproszenia S t r e s z c z e n i e Analizie poddano dane o użytkowości rozpłodowej 91 macior rasy puławskiej oraz o wzroście urodzonych przez nie 409 miotów w czterech kolejnych sezonach roku. Analizowano dane za okres 5 lat (1999-2004). Wykazano wyższą płodność loch oproszonych w sezonie zimowym i jesiennym w porównaniu z oproszonymi w sezonie wiosennym. Stwierdzono wpływ sezonu na wiek pierwszego oproszenia i długość okresu jałowienia badanej subpopulacji macior. Średni okres zasuszenia loch oproszonych w sezonie letnim był istotnie dłuższy niż oproszonych w pozostałych sezonach roku. 91