Behaviour and growth performance of low-birth-weight piglets cross-fostered in multiparous sows with piglets of higher birth weights

L.P Souza,L.F Hernig,J.E Faccin,H.C.C Fries,G Heim,F.P Bortolozzo,M.L Bernardi,I Wentz,B.T Marimon

doi:10.1590/1678-41626379

Abstract

The aim of the study was to evaluate the behaviour, pre-weaning survival rate and growth performance of low birth weight (BW) piglets cross-fostered with piglets of higher weights. Piglets were transferred to 60 foster sows, and divided in three groups (G; n=20): G1- 12 low BW piglets (0.80 - 1.25kg); G2- six low BW piglets and six intermediate BW piglets (1.40 - 1.60kg), and G3- six low BW piglets and six high BW piglets (>1.70kg). For the analysis, groups G2 and G3 were subdivided in LG2 (six G2 light piglets); IG2 (six G2 intermediate piglets), LG3 (six G3 light piglets), and HG3 (six G3 heavy piglets). Behavioural observations were carried out on days 1, 2, 4 and 6 (visual direct observation) and on days 3 and 5 (video recording) after birth. The percentage of missed nursings was higher in LG3 piglets than in LG1, IG2 and HG3 piglets, on days 1 and 2. On day 4, light piglets (LG1, LG2 and LG3) missed more nursings than IG2 and HG3 piglets. On day 3, video recording showed a higher percentage of missed nursings in LG1, LG2, and LG3 piglets as compared to HG3 piglets. On day 1, the number of fights during nursing was higher in IG2 than in LG1 and LG3 piglets. Also on day 1, number of fights and percentage of piglets engaged in fights, during 15min after nursing, were higher in LG1, LG3 and HG3 than in LG2 piglets. More playful behaviours were observed on day 2 in IG2 and HG3 piglets compared to LG1, LG2 and LG3 piglets. Light piglets (LG1, LG2, and LG3) presented similar body weight on days 4, 8, 12 and 16 after birth, regardless of being mixed with piglets of higher weights or not; however, the survival rate until day 16 was most compromised in LG3 piglets compared to the other groups. Despite the lack of influence of littermates' weight on the growth of low BW piglets, their survival rate indicates that they should not be mixed with high BW piglets.

Highlights

Sows have become increasingly prolific due to genetic improvement (Quiniou et al, 2002); this resulted in large within-litter variability in birth weight and higher numbers of low-birth-weight piglets (Milligan et al, 2001)
Piglet birth weight was similar for LG1, LG2, and LG3 piglets (1.08±0.03kg,1.10±0.03kg and 1.09±0.03kg, respectively), but were lower than those in IG2 (1.50±0.03kg) and HG3 (1.80±0.03kg) piglets, confirming the aim of having piglets with different initial weights
By direct visual observation (Figure 1), it was observed that LG3 piglets missed more nursings (P

Summary

Introduction

Sows have become increasingly prolific due to genetic improvement (Quiniou et al, 2002); this resulted in large within-litter variability in birth weight and higher numbers of low-birth-weight piglets (Milligan et al, 2001). Cross-fostering is carried out to obtain more homogeneous litters in terms of number or birth weight of piglets (Neal and Irvin, 1991; Straw et al, 1998; Robert and Martineau, 2001), thereby reducing weight variation within the litter (Straw et al, 1998) and the effect of competition on the growth performance and pre-weaning mortality, mainly of light newborn piglets. In commercial farms cross-fostering is often indiscriminately performed during the entire lactation period, resulting in delayed growth of adopted piglets

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