Seasonal influences on the litter size at birth of pigs are more pronounced in the gilt than sow litters

Autor: Wichai Tantasuparuk, M. Techakumphu, Padet Tummaruk, Annop Kunavongkrit
Rok vydání: 2010
Předmět:
Zdroj: The Journal of Agricultural Science. 148:421-432
ISSN: 1469-5146
0021-8596
DOI: 10.1017/s0021859610000110
Popis: SUMMARYThe aim of the present study was to use data from herds to demonstrate the degree of seasonal influence on litter size at birth in gilts compared to sow parities 2, 3–5 and older (parities ⩾6) in a conventional, open-housing system for commercial pig herds in the northeastern part of Thailand. Data were obtained during a 3-year period from July 2005 to June 2008. The data analysed included observations on 25 835 litters from 8100 sows. Total number of piglets born per litter (TB), number of piglets born alive per litter (BA), proportion of stillborn piglets per litter (SB) and proportion of mummified fetuses per litter (MF) were analysed using a general linear mixed model procedure. The influence of temperature, relative humidity and temperature-humidity index (THI) on TB, BA, MF and SB were also analysed. The meteorological data were merged with the reproductive data and the means of temperature, relative humidity and THI during 115 days before farrowing were calculated and included in the statistical models. The results revealed that sows that farrowed in the hot season had a larger TB and BA than sows that farrowed in the rainy (PPPP=0·01), 0·3 (P=0·003) and 0·3 (P=0·02) TB fewer than those that farrowed in the hot season. In the first parity, MF increased from 0·022 to 0·042 when the mean temperature during gestation increased from 26 to 29°C (PPPPP>0·05). In conclusion, inferior litter size at birth was observed in sows that farrowed in either rainy or cool seasons. High temperature, high relative humidity and/or high THI during gestation significantly reduced the number of total piglets born per litter. The influence of season, temperature, relative humidity and/or THI on litter size at birth was more evident in the gilts than the sows. These data indicated that various strategies to reduce temperature in the open-housing system for pregnant gilts and sows in Thailand are not adequate and the proper housing of pregnant gilts should be emphasized.
Databáze: OpenAIRE
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