Gómez MM, Segura-Correa JC , Rodríguez-Buenfil JC

Language: Spanish
References: 17
Page: 23-28
PDF size: 28.77 Kb.

ABSTRACT

Introduction. Research in some countries has demonstrated that sow production is affected by year or season of farrowing and by the sow’s parity number. The effects are manifested in the different indicators of production, such as: fertility, and size and weight of the litter at birth or at weaning. It is important to know magnitude of the effect of parity number on preweaning traits in order to make decisions on the culling and replacement systems, therefore enabling appropiate decisions on the management system in the farm to be taken. The objective of this study was to determine the effect of parity number of the sow, and yearly and bimonthly effects on preweaning traits on a commercial farm in Yucatan, Mexico. Material y methods. Two annual records from a farm located in the central region of the state of Yucatan, Mexico were used. 8570 y 7841 data on litter size and weight of the piglets at birth and at weaning, respectively, were analysed. Monthly records were combined to obtain six bi-mon thly periods. Litter size at birth was defined as the total number of piglets born (dead and alive). The statystical model which described the response variables included the effects of year, bi-monthly and sow´s parity number. Results. The general means and standard deviations for litter size at birth (LSB), number of piglets born alive (NBA), piglets average weight at birth (AWB), number of piglets weaned (NPW) and piglets average weight at weaning (AWW) were: 10.99±2.93 piglets, 10.24±2.83 piglets, 1.58±0.25 kg, 9.44±1.11 piglets y 5.81±0.89 kg, respectively. Sow’s parity, number, year of farrowing and bi-month of farrowing effects were found on LSB and NBA, however year of farrowing had no effect on AWB. With respect to NPW only yearly and bi-monthly effects were found (p‹0.05). AWW was affected by the three factors studied (p‹0.05). In general, the means for the preweaning traits were better in 1995 than in 1994. Bi-monthly effect did not show any trend over time. Fist and second farrowing sows had lighter litters than those with 3 or 4 farrowings. However, at weaning, sows had similar litter sizes. Sows with 1 or 4 farrowing had the lowest AWW (p‹0.05). Discusion. AWB and AWW were influenced by the sow’s parity number, whereas year and bimonth were important sources of variation for all the variables studied.

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