Physiological responses of growing pigs to high ambient temperature and/or inflammatory challenges

Abstract

-Global warming is one of the major environmental threats facing the world in the 21st century. This fact will have a significant impact on pig production due to its direct effects on welfare, health, and performance of pigs. Besides, the effects of high temperatures will presumably become more important over the next decades due to the development of pig production in developing countries mainly located in tropical and subtropical areas, where animals are often exposed to ambient temperatures above their thermal comfort zone. Furthermore, pigs reared in tropical areas are often confronted to sanitary challenges including poor hygiene conditions, lack of respect for sanitary rules, and pathogens. This results in the stimulation of the immune system and, as a consequence, in the production of pro-inflammatory cytokines and neuroendocrine adjustments that, in turn, usually have a negative impact on growth and feed efficiency. Although the effects of high ambient temperature and disease on pig physiology and performance have been well documented in literature, little is known about the associated effects of both factors. This understanding may contribute to a better quantification and comprehension of the physiological and metabolic disturbances occurring in practical conditions of pig production in tropical areas and, more generally, in many other geographic areas that will be influenced by the perspective of global warming. Therefore, the objective of this work is to provide an overview of recent research advances on the physiological responses of growing pigs during acclimation to high ambient temperature and on the potential effects of high ambient temperature on the ability of growing pigs to resist, cope with, or recover from an inflammatory challenge.

Spray‐dried porcine plasma improves feed intake of weaned piglets subjected to heat stress

“…Also, the rectal temperatures were higher for piglets in the HS environment compared with piglets on the TN environment. This indicates that the pig's physiological mechanisms as reduced voluntary feed intake, greater respiration rate, less production of T3 and T4, increased blood flow and decreased activity (Campos, Le Floch'h, Noblet, & Renaudeau, ) were not sufficient to reduce the heat production of the piglets (Huynh, Aarnink, Gerrits et al, ; Patience, Umboh, Chaplin, & Nyachoti, ; Renaudeau, Huc, & Noblet, ). Heat stress is a physiological condition resulting from an animal's inability to regulate their internal euthermic temperature (Baumgard et al, ).…”

Pigs fed various levels of crude protein and raised above the thermoneutral zone: effects on protein metabolism and nitrogen balance

“…According to Campos et al (2017), the process of adaptation to high temperatures is biphasic, in the first 48 hours after exposure, there was an increase in the internal temperature, an increase in heat losses and lower heat production associated with reduction in feed intake may have contributed to the differences in cholesterol and FRAP. The absence of effect on these variables, according to Campos et al (2017), was a consequence of adaptation to heat; this is the stage of reduction in thyroid hormone levels and reduction of endogenous heat production. Freitag et al (2014) obtained similar results, where protein reduction in the diet had no effect on plasma cholesterol levels in piglets raised under heat stress.…”

“…In manuals of nutritional requirements, consideration of heat stress has appeared only recently (Rostagno et al, 2017). Nevertheless, the process of adaptation to heat is biphasic, characterized initially by rapid changes, including changes in feed intake, respiratory and heart rates (Huynh et al, 2005;Renaudeau et al, 2010 andCampos et al (2017) followed by changes in physiological variables. It is important to evaluate serum variables over time to identify new serum indicators employing rapid methodologies to identify physiology status of pigs raised under temperatures above the thermoneutral zone.…”

Теплостійкість Свиней Різних Порід

“…До екологічно несприятливих стресових факторів, що впливають на ріст, розвиток, продуктивність та адаптивні здібності сільськогосподарських тварин відносять і підвищення зовнішніх температур вище комфортних. Відомо, що довготривала чи сильна дія технологічних стресів може призвести до порушення нормального функціонування організму, виключаючи в ньому стресреакцію [19].…”