Influence of Cold Environments on Growth, Antioxidant Status, Immunity and Expression of Related Genes in Lambs

Abstract

Cold climates may be a risk to the health and welfare of lambs during winter because cold environments alter the physiological processes of lambs, and we used cold environments with three different temperature gradients—an indoor heating control group (IHC) using electric heating; an indoor temperature group (IT) with intermittent and slight degrees of stimulation of coldness; an outdoor temperature group (OT) exposed to cold environments in an external natural environment. The results showed that the lambs in the OT group had a greater decrease in the average daily gain (ADG) and increase in the average daily feed intake (ADFI) and the feed-to-gain ratio (F:G) compared to the other two groups. The decrease in immunoglobulin A (IgA) and interleukin 2 (IL-2) contents and IL-2 gene expression, and the increase in tumor necrosis factor α (TNF-α) content and TNF-α and nuclear factor kappa-B p65 (NF-κB p65) gene expressions in the OT group suggested that the lambs had a compromised immune status in cold environments. Moreover, the decrease in catalase (CAT), glutathione peroxidase (GPx), total superoxide dismutase (T-SOD), and total antioxidant capacity (T-AOC) levels, and CAT, GPx, SOD1, SOD2, and nuclear factor-erythroid 2-related factor 2 (Nrf2) gene expressions, and the increase in malondialdehyde (MDA) in the OT group suggested that the lambs had a lower antioxidant defense capacity in cold environments. Thus, in extreme cold, lambs kept outdoors could reduce growth, immune function and antioxidant status. However, shelter feeding in winter could relieve the stress of cold environments on lambs, and housing with heating equipment was more conducive to the improve growth, immune, and antioxidant function of the lambs.

Heating Drinking Water in Cold Season Improves Growth Performance via Enhancing Antioxidant Capacity and Rumen Fermentation Function of Beef Cattle

“…Studies have demonstrated that cold stress induces stress responses in ruminants, resulting in elevated concentrations of serum glucocorticoids, triiodothyronine, and thyroxine [ 39 ]. In our study, the RTW increased the concentrations of serum T3 and T4, which could contribute to the promotion of gluconeogenesis and hepatic glycogen synthesis, enhance thermogenesis, and improve the resistance of the organism to low-temperature environments [ 40 ].…”

Energy Conservation in a Livestock Building Combined with a Renewable Energy Heating System towards CO2 Emission Reduction: The Case Study of a Sheep Barn in North Greece

“…During colder periods, though, the temperature inside the sheep barn is lower than the lower critical temperature of the animals' TNZ. As a result, the animals consume more feed to retain their body temperature within their TNZ, and they face a change in their metabolic reactions [6,16], which leads to an increase in feed intake during the winter months [17][18][19] without leading to a weight increase [20]. As reported in the literature, an increase in feed intake leads to an increase in GHG emissions [21][22][23].…”

Cold Exposure Regulates Hepatic Glycogen and Lipid Metabolism in Newborn Goats

“…A previous study reported that hypothermia induced by cold stress can lead to hypoxia, hypoglycaemia, and metabolic acidosis in lambs [ 3 ]. Additionally, the cold environment affects the growth performance, antioxidant status, immune function and expression of related genes in lambs [ 4 ]. Based on the various adverse effects of cold stress on newborn goats, this study aims to explore the regulatory effect of cold exposure on hepatic metabolism in newborn goats.…”