Effects of Housing and Management Systems on the Growth, Immunity, Antioxidation, and Related Physiological and Biochemical Indicators of Donkeys in Cold Weather.

The study was designed with a 2 × 2 factorial experiment to evaluate the effects of growth performance, immune function, antioxidant status, blood biochemical indexes, and hormone levels of donkeys in different housing and management systems in cold weather. Twenty-four male donkeys with similar body weight and age were randomly allocated into four treatment groups that were as follows: a cold-water-drinking group without a windproof facility, a lukewarm-water-drinking group without windproof facilities, a cold-water-drinking group with a windproof facility, and a lukewarm-water-drinking group with a windproof facility. The experiment lasted for 42 days. The results showed that windproof facilities increased average daily gain (ADG) and decreased average daily feed intake (ADFI) and feed-to-gain ratio (F:G) at all time periods (p < 0.01) of the experiment. Windproof facilities increased the digestibility of dry matter (DM), crude fat (CF), crude protein (CP), ash, calcium (Ca), and phosphate (P) on day 21 (p < 0.01), and increased the digestibility of DM, CF, ash, and P on day 42 (p < 0.01). The respiration rate and the skin temperature of the abdomen and legs increased (p < 0.05) and rectal temperature tended to increase (p = 0.083) by adopting windproof facilities at 07:00; the windproof facilities tended to increase the skin temperature of the ears and abdomen (p = 0.081, p = 0.091) at 14:00. For the blood parameters, with windproof facilities, the concentrations of total protein (TP), blood urea nitrogen (BUN), triglyceride (TG) and high-density lipoprotein cholesterol (HDL-C) increased (p < 0.05) and glucose (GLU) concentration decreased (p < 0.05) at 07:00 on day 21; the concentrations of TG and cholesterol (CHO) increased and the concentrations of TP, BUN, and GLU decreased at 07:00 on day 42 (p < 0.05). The concentrations of adrenocorticotropic hormone (ACTH), cortisol (COR), triiodothyronine (T3), and thyroxine (T4) decreased (p < 0.05) at 07:00 on day 21, and T4 concentration decreased (p < 0.05) at 07:00 on day 42. The concentrations of interleukin-4 (IL-4), immunoglobulin A (IgA), immunoglobulin G (IgG), and immunoglobulin M (IgM) increased (p < 0.01) and the concentrations of interleukin-1β (IL-1β) and tumor necrosis factor-alpha (TNF-α) decreased (p < 0.01) on days 21 and 42. The activities of total superoxide dismutase (T-SOD) and glutathione peroxidase (GPx) increased (p < 0.05), and malondialdehyde (MDA) concentration decreased (p < 0.01) on day 21; the activities of T-SOD and catalase (CAT) increased (p < 0.05), and MDA concentration decreased (p < 0.01) on day 42. However, under the conditions of this experiment, water temperature did not affect the above indexes on days 21 and 42. These results indicated that adopting windproof facilities in a cold climate can mitigate the effects of atrocious weather on the production performance of donkeys.