Effects of early feed restriction and cold temperature on lipid peroxidation, pulmonary vascular remodelling and ascites morbidity in broilers under normal and cold temperature

Abstract

Two experiments were conducted to evaluate the effects of early feed restriction on lipid peroxidation, pulmonary vascular remodelling and ascites incidence in broilers under normal and low ambient temperature. In experiment 1, the restricted birds were fed 8h per day either from 7 to 14 d or from 7 to 21 d, while the controlled birds were fed ad libitum. In experiment 2, the restricted birds were fed 80 or 60% of the previous 24-h feed consumption of full-fed controls for 7 d from 7 to 14 d. On d 14, half of the birds in each treatment both in experiment 1 and experiment 2 were exposed to low ambient temperature to induce ascites. Body weight and feed conversion ratio were measured weekly. The incidences of ascites and other disease were recorded to determine ascites morbidity and total mortality. Blood samples were taken on d 14, 21, 28, 35 and 42 to measure the plasma malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). On d 42, samples were taken to determine the right/total ventricular weight ratio (RV/TV), vessel wall area/vessel total area ratio (WA/TA) and mean media thickness in pulmonary arterioles (mMTPA). Low-temperature treatment increased plasma MDA concentration. When broilers were exposed to a cool environment for 3 weeks, plasma SOD and GSH-Px activity were decreased compared with normal-temperature chicks. RV/TV, WA/TA and mMTPA on d 42 were increased in birds exposed to cold, consistent with the increased pulmonary hypertension and ascites morbidity. Early feed restriction markedly decreased plasma MDA concentration. The plasma SOD and GSH-Px activity of feed-restricted birds were markedly higher than those fed ad libitum on d 35 and d 42. All early feed restriction treatments reduced ascites morbidity and total mortality. On d 42, the RV/TV, WA/TA and mMTPA of feed-restricted broilers were lower than that of the ad libitum-fed broilers. The results suggested that early feed restriction alleviated the lipid peroxidation, promoted the activity of enzymatic antioxidant and inhibited pulmonary vascular remodelling. These changes might be associated with reduced ascites incidence.

Effect of Energy Restriction on Growth, Slaughter Performance,Serum Biochemical Parameters and Lpin2/WDTC1/mRNA Expressionof Broilers in the Later Phase

“…Agreement with the report of Pan et al (2005), here 30% energy restriction from 19∼48 d significantly increased serum SOD activity and serum UA level, and decreased serum MDA concentration. The increased antioxidant enzymatic activity might contribute to decreased lipid peroxidation damage (Pan et al, 2005). Decreased serum MDA concentration indicated the decrease in the generation of reactive oxygen species (ROS).…”

“…Short-time feed restriction in the early growth stage of broilers has been adopted in commercial broiler production to reduce the mortality rate, the incidence of metabolic disorders such as ascites, lameness, sudden death syndrome and fat deposition (Lippens et al, 2000;Camacho et al, 2004;Pan et al, 2005). Such system results in temporary reduce of growth rate, while the normal weight of broilers can be attained on removal of feed restriction, thus improving the feed efficiency and decreasing the feeding cost (Yang et al, 2009).…”

Antioxidant Systems in Poultry Biology: Superoxide Dismutase

“…Hepatic mitochondrial SOD activity decreased at 14 d in feedrestricted broiler chicks [136]. However, the plasma SOD activity of feed-restricted birds was markedly higher than those fed ad libitum on d 35 and d 42 [126].…”

“…In fact, the increase in metabolic rate at temperatures below the comfort zone (cold stress) is a significant cause of increased mortality from the pulmonary hypertension syndrome (ascites) in broilers [125]. Initially, it was shown that when broilers were exposed to a cool environment for 3 weeks, plasma SOD activity was decreased [126]. Similarly, cold exposure reduced chicken plasma SOD and supplemental L-carnitine (100 mg/kg) was shown to restore the SOD activity in cold-stressed birds [127].…”

Gene Expression Profiling of Broiler Liver under Cold Stress by High-Throughput Sequencing Technology

“…Excessive cold stress causes a series of physiological and metabolic changes in broiler chickens, such as electrolyte and acid-base imbalances, reduced endocrine function (Olanrewaju et al, 2010), and reductions in production performance including animal feed intake, body weight and feed conversion ratio (Spinua and Degena, 1993). Cold stress also disrupts the balance of the oxidant/ antioxidant system, leading to biological membrane damage and further damaging tissue integrity and negatively influencing animal health and production (Pan et al, 2005;Mujahid and Furuse, 2009). At the same time, cold stress affects tissue structure lesions, inducing various types of disease (Sahin and Gumuslu, 2004).…”