Piglet birth weight is related to time to first walk after birth

Pre-weaning mortality contributes significantly to the productivity of the breeder herd and hence herd feed conversion efficiency through the number of sows required to maintain progeny production volume. In farrowing houses, the major cause of pre-weaning mortality is sow overlay of neonatal piglets (50%), unviable piglets and runts (30%) and scours (12%) and over half of the total losses occur within the first 48 h after farrowing (Morrison et al. 2009). Morrison et al. (2009) identified that piglets at risk of dying in the pre-weaning period are those that have a low birthweight, do not suck within 40 min of farrowing, have a low rectal temperature 60 min post-birth, and have low serum immunoglobulin G concentrations 24 h post-birth. The aim of this experiment was to investigate the relationships between piglet birthweight and time to first breath, walk and suck. It was hypothesised that birthweight would be negatively related to time to first breath, walk and suck post-birth.

Eighty sows from Parity 1 to 9 (Large White × Landrace, PrimeGro™ Genetics, Corowa, NSW) and their litters (1096 piglets) were monitored during the farrowing process. Individual live weight of piglets was measured immediately post-farrowing. Time points for each piglets’ birth, first breath, first attempt to walk, and first suck were recorded. The data was linear and was analysed by Pearson’s bivariate correlation, two-tailed analysis using SPSS (v21.0, IBM, Armonk, NY, USA).

There was a significant (P < 0.01) weak negative correlation between birthweight and time to first breath and suck (Table 1). There was a significant (P < 0.01) strong correlation between birthweight and time to first walk (R² = 0.76), which means that birthweight accounts for 76% of the variability of time to first walk post-birth. Baxter et al. (2008) noted that piglets that have low birthweights often have poor thermoregulatory ability and depleted body energy reserves, causing them to receive small amounts of colostrum in the early stages of birth which reduces their viability and survivability. Strategies to increase birthweight of piglets may have a positive impact on the ability of these animals to walk (move away from sow and reduce risk of being overlain by the sow) and suck more quickly, which may improve piglet survival within the first 24 h post-birth.

Table 1.  Pearson correlation coefficients (r) between birthweight, time to first breath, walk and suckle