Supplementation of palmitoleic acid improved piglet growth and reduced body temperature drop upon a cold exposure

Abstract Background Survival of piglets poses a significant challenge in the initial days after birth because piglets are lacking readily oxidizable brown adipose tissue and born with limited amount of body reserves, which in turn limited theirthermogenic capacity. This study investigated the effects of palmitoleic acid (PA) supplementation on growth performance, maintenance of body temperature, muscle fatty acid (FA) compositions, and energy metabolism in milk replacer fed piglets. Forty-eight piglets were stratified by body weight and randomly assigned to one of four dietary treatments (0%, 1%, 2%, and 3% PA supplementation as percent of milk replacer). Piglets were weighed daily, and half in each dietary treatment groups were exposed daily to low temperature for 2 h. Plasma and tissue samples were collected at the end of the experiment for further analyses. Results Contents of C16:1n-7 and C18:1n-7 in both plasma and liver (P < 0.001), and C16:1n-7 (P < 0.001) in semimembranosus increased linearly as PA levels increased. Most plasma FA levels (except C16:1n-7, C16:1n-9 and C22:5n-3) were lower in piglets exposed to low temperature than those that were not. Plasma glucose, triglycerides and lactate dehydrogenase levels increased linearly with PA supplementation (P< 0.001). Piglets’ average daily gain, liver weight, liver glycogen pools, and gallbladder increased linearly with PA supplementation (P < 0.05, P < 0.01, P < 0.05, and P < 0.001, respectively), but lung weight, liver nitrogen content, and body temperature drop at cold exposure decreased linearly with PA supplementation (P < 0.01, P < 0.001, and P < 0.05, respectively). Piglets exposed to low temperature had greater liver nitrogen (P < 0.05) and lactate dehydrogenase (P < 0.001) contents, but had lower liver weight (P < 0.01) and plasma lactate concentration (P< 0.05) than those that were not. Conclusion Dietary supplementation of PA increased C16:1n-7 concentrations in plasma, liver, and semimembranosus as well as average daily gain of the piglets. The drop in body temperature of the piglet upon cold exposure decreased linearly with increasing PA supplementation.