Genetic parameters for thermoregulation and production traits in lactating sows reared in tropical climate

Abstract

The objective of this study was to estimate the genetic parameters for thermoregulation traits and the relationships with performance of Large White lactating sows reared in a tropical humid climate. The thermoregulation traits were rectal temperature (RT), cutaneous temperature (CT) and respiratory rate (RR) during lactation measured in the afternoon (1200 h) and in the morning (0700 h). The production traits were sow's average daily feed intake (ADFI), litter BW gain (LBWg) and sow's proportion of BW change between farrowing and weaning (BWc). Complete data included 931 lactating performance on 329 Large White sows from the INRA experimental unit in Guadeloupe (French West Indies). Random regression models using linear spline functions were used for longitudinal data (RT, CT, RR and daily feed intake). Results showed that when ignoring values at the beginning and the end of lactation, the traits studied can be treated as the same trait throughout days of lactation, with fairly constant heritability and variance. However, largest heritabilities and genetic variances were estimated in mid-lactation. Heritability estimates on average performance during lactation were low to moderate for thermoregulation traits (0.35 ± 0.09 for RT, 0.34 ± 0.12 for CT and 0.39 ± 0.13 for RR). Heritability estimates for production traits were 0.26 ± 0.08 for ADFI, 0.20 ± 0.07 for BWc and 0.31 ± 0.09 for LBWg. Significant genetic correlations between thermoregulation traits and production traits were only obtained for ADFI and RR (0.35 ± 0.12). From this study it can be concluded that thermoregulation traits are heritable, indicating that there are genetic differences in heat stress tolerance in lactating Large White sows.

Characterization of the acute heat stress response in gilts: III. Genome-wide association studies of thermotolerance traits in pigs

“…To the best of our knowledge, no prior study reported estimates of heritability for thermotolerance traits in pigs from genome-wide SNP data. Very recently, Gourdine et al (2017) reported heritability estimates of 0.35 and 0.39 for T R and RR, respectively, in lactating sows reared in a tropical climate. Generally, the value observed for T R in the present study is higher than the range of values reported in cattle (0.11 to 0.44) (Da Silva, 1973;Morris et al, 1989) and poultry (0.36) (Taouis et al 2002).…”

Interactions between sire family and production environment (temperate vs. tropical) on performance and thermoregulation responses in growing pigs1,2

“…It should be noticed that the THI used in the present study was formulated to monitor discomfort from temperature and humidity in dairy cattle. This index has been used in studies on HS of pigs (Zumbach et al, 2008;Gourdine et al, 2017). To our knowledge, there is no THI equation directly formulated for pig production performance.…”

“…Moderate to strong negative correlations between body temperatures and production traits have been reported, but with large SE (Renaudeau et al, 2004;Gourdine et al, 2017). In the present study, no significant correlations between RT or ST and production traits were reported, expected for RT 23 with BFT 23 and ST 23 with ADG 11-23 in TEMP conditions (r = −0.07 and r = −0.09, respectively) and RT 23 with BFT 23 and ST 23 with BFT 23 in TROP conditions (r = −0.10).…”

Use of Temperature, Humidity, and Slaughter Condemnation Data to Predict Increases in Transport Losses in Three Classes of Swine and Resulting Foregone Revenue

“…Cull sows are older and may travel farther to slaughter (due to fewer plants that make sow meat products) than other swine classes and therefore have a greater risk for welfare problems (22). In addition, genetic selection of sows that has allowed significant improvements in reproductive traits has also increased metabolic heat production resulting in a decrease in the sow’s ability to cope with high ambient temperatures (23, 24). …”