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

Abstract

The aim of this study was to evaluate the effect of 2 climatic environments (temperate [TEMP] vs. tropical humid [TROP]) on production and thermoregulation traits in growing pigs. A backcross design involving Large White (LW; heat sensitive) and Creole (CR; heat tolerant) pigs was studied. The same 10 F LW × CR boars were mated with related LW sows in each environment. A total of 1,298 backcross pigs ( = 634 pigs from 11 batches for the TEMP environment and = 664 pigs from 12 batches for the TROP environment) were phenotyped on BW (every 15 d from wk 11 to 23 of age), voluntary feed intake (ADFI, from wk 11 to 23), backfat thickness (BFT; at wk 19 and 23), skin temperature (ST; at wk 19 and 23), and rectal temperature (RT; at wk 19, 21, and 23). The feed conversion ratio was computed for the whole test period (11 to 23 wk). The calculation of the temperature-humidity index showed an average difference of 2.4°C between the TEMP and TROP environments. The ADG and ADFI were higher in the TEMP environment than in the TROP environment (834 vs. 754 g/d and 2.20 vs. 1.80 kg/d, respectively; < 0.001). Body temperatures were higher in the TROP environment than in the TEMP environment (35.9 vs. 34.8°C for ST and 39.5 vs. 39.3°C for RT, respectively; < 0.001). Most of the studied traits (i.e., BW, BFT, ADG, ADFI, and RT) were affected by sire family × environment interactions ( < 0.05), resulting in "robust" and "sensitive" families. Our results show a family dependency in the relationships between heat resistance and robustness, suggesting the possibility of finding genotypes with high production and low heat sensitivity. Further research is needed to confirm the genetic × environment interaction and to detect QTL related to heat tolerance.

Effect of chronic and acute heat challenges on fecal microbiota composition, production, and thermoregulation traits in growing pigs1,2

“…The effects of tropical climate on performance from 11 to 23 wk of age have already been detailed by Rosé et al (2017). In the subset of pigs with fecal samples included in our study, we confirmed that ADFI and ADG were significantly reduced in TROP compared with TEMP climate.…”

“…In TROP, the combined effects of high temperature and high relative humidity possibly accentuate the ADFI reduction due to heat (Granier et al, 1998) due to the low ability of the pigs to lose heat by evaporation under high ambient humidity. In agreement with Rosé et al (2017), feed efficiency tended to increase in TROP conditions. As suggested by Renaudeau et al (2011), in moderate HS conditions, feed efficiency increases due to feed restriction effect.…”

“…Créole breed is a local tropical breed. Full details on the experimental design are given by Rosé et al (2017). Finally, 558 and 564 backcross pigs (castrated males and females) in 12 batches were produced in TEMP and TROP climates, respectively.…”

“…Whatever the climate, pigs had a free access to water and were fed ad libitum with a commercial grower diet presented as pellets. For practical reasons, the diets in both environments were formulated with different raw materials (wheat, corn, barley, and soybean meal in TEMP, and corn and soybean meal in TROP) but resulted in the same chemical and nutritional composition (16.0% vs. 16.4% crude protein and 13.9 and 13.5 MJ digestible energy/kg in TEMP and TROP area, respectively; Rosé et al, 2017). In both environments, the diets did not contain any antibiotic, pre- or pro-biotic, or any other extracts.…”

Use of geographic information system tools to predict animal breed suitability for different agro-ecological zones

“…(2017) and Rosé et al . (2017) showed that differences between temperate and tropical climates can cause significant genotype by environment interaction (G×E), which affects productivity. This breed-by-environmental mismatch is usually estimated as G×E, the genetic correlation for a given set of traits estimated in two environments.…”