Birth weight threshold for identifying piglets at risk for preweaning mortality

Abstract

<jats:title>Abstract</jats:title> <jats:p>Several studies have suggested there is a critical relationship between piglet birth weight and preweaning mortality. Thus, the objective of the current work was to identify a birth weight threshold value for preweaning mortality. Birth weight and survival data from two studies involving a combined total of 4,068 piglets from 394 litters on four commercial farms (three European, one U.S.) were compiled for a pooled, multistudy analysis. Overall preweaning mortality across the two studies was 12.2%. Key variables used in the analysis were piglet birth weight (measured within 24 h of birth) and corresponding survival outcome (dead or live) by weaning at 3–4 wk of age. A mixed effects logistic regression model was fit to estimate the relationship between preweaning mortality and birth weight. A random effect of study was included to account for overall differences in mortality between the two studies. A piecewise linear predictor was selected to best represent the drastic decrease in preweaning mortality found as birth weight increased in the range of 0.5–1.0 kg and the less extreme change in weight above 1.0 kg. The change point of the birth weight and preweaning mortality model was determined by comparing model fit based on maximizing the likelihood over the interval ranging from 0.5 to 2.3 kg birth weight. Results from the analysis showed a curvilinear relationship between birth weight and preweaning mortality where the birth weight change point value or threshold value was 1.11 kg. In the combined data set, 15.2% of pigs had birth weights ≤1.11 kg. This subpopulation of pigs had a 34.4% preweaning mortality rate and represented 43% of total preweaning mortalities. These findings imply interventions targeted at reducing the incidence of piglets with birth weights ≤1.11 kg have potential to improve piglet survivability. Additional research is needed to validate 1.11 kg as the birth weight threshold for increased risk of preweaning mortality.</jats:p>

Effect of method of drying piglets at birth on rectal temperature over the first 24 h after birth1

“…The average number of piglets born alive per litter (11.5 to 12.4) was similar to that for U.S. herds reported by PigChamp at the time this study was carried out (13.2 piglets per sow; 2017, 2018). Average piglet weights (1.41 to 1.44 kg) were similar to those reported in recent commercial studies (e.g., Vasdal et al, 2011 ; Feldpausch et al, 2019 ).…”

“…A major factor associated with this increase is the reduction in average piglet birth weight due to the increase in litter sizes that have occurred in commercial dam lines over a similar time period (PigChamp, 2019). Estimates suggest that approximately 10 to 15% of piglets born are of low birth weight (i.e., weighing <1 kg) and that mortality in these piglets is extremely high, often exceeding 50% ( Feldpausch et al, 2019 ).…”

Changes in Faecal Microbiota Profiles Associated With Performance and Birthweight of Piglets

“…Poor development of the GIT of IUGR pigs persists pre-and post-weaning (D'Inca et al, 2011;Dong et al, 2014), with reduced rate of GIT maturation thought to negatively affect performance (Wang et al, 2005). LBW pigs represent a considerable economic problem to pig producers as a result of increased morbidity and mortality (Hales et al, 2013;Ferrari et al, 2014;Feldpausch et al, 2019), higher propensity to develop enteric health problems, poorer feed efficiency as well as carcase yield and quality with increased adiposity (Rehfeldt et al, 2008;D'Inca et al, 2011;Nissen and Oksbjerg, 2011;Zhang et al, 2018). However, a proportion of LBW pigs exhibit compensatory growth within the same environment as those who remain stunted (Paredes et al, 2012;Douglas et al, 2013;Huting et al, 2018), although an explanatory mechanism for this phenomenon is yet to be proposed.…”

Fat deposition deficiency is critical for the high mortality of pre-weanling newborn piglets

“…Piglets with low birth weight less than 1.13 kg are at risk of lower survival rate and longer time to market [ 14 ]. Previous study has proposed the relationship between birth weight and survival rate for piglets, when increased birth weight class by 100, 150, and 200 g; the survival rate of piglets would increase to 85.6%, 86.6%, and 87.6%, respectively; and time to reach 100 kg would decrease from 178.7 d to 176.1 d, 174.5 d, and 172.9 d, respectively [ 14 ]. Another study has also demonstrated that the lower littermate weight was associated with higher mortality [ 15 ].…”