The effects of maternal thiamine nutrition on thiamine status of the offspring in broiler chickens

Effects of Different Forms and Levels of Selenomethionine on Productive Performance and Antioxidant Status of Broiler Breeders and Its Offspring

This study was conducted to investigate the effects of different selenomethionine (SM) forms and levels on productive performance and antioxidant status of broiler breeders and its offspring. Four hundred eighty 48-week-old Lingnan Yellow broiler breeders were randomly divided into four groups, provided basal diet with 0.15 or 0.30 mg/kg Se coming from two SM forms of DL-SM and L-SM. The experiment included a 4-week pretreatment period and an 8-week trial period. During the trial period, eggs were incubated once a week under standard conditions. The broiler breeders were slaughtered after the trial period. At the same time, 15 1-day-old chicks were selected at random per replicate and killed. The results showed that different SM forms and levels had no significant differences in average egg weight, feed intake, and feed-to-egg ration. The DL-SM group in contrast to the L-SM group induced a notable elevation of glutathione peroxidase (GPx) activity in serum (P < 0.01) and liver (P < 0.05), and the 0.15 mg/kg group had higher GPx activity than 0.30 mg/kg in serum (P < 0.01) and pancreas (P < 0.05). Different SM forms showed no significant differences in total antioxidant capability (T-AOC). Diets with 0.15 mg/kg Se exhibited a higher level of T-AOC in serum (P < 0.01) and some tissues. Besides, malondialdehyde (MDA) concentrations in serum, liver, and kidney significantly decreased due to the supplementation of DL-SM. Supplemental 0.15 mg/kg Se reduced MDA concentrations in kidney and muscle. The offspring of broiler breeders fed on DL-SM had higher GPx activity in liver and kidney than L-SM treatment. Supplemental 0.15 mg/kg Se also improved GPx activity in kidney and muscle and T-AOC in kidney of 1-day-old chicks. In summary, our study demonstrated that compared with L-SM, DL-SM was more effective for enhancing the antioxidant status of broiler breeders and its offspring. Moreover, the recommended level of Se supplementation was 0.15 mg/kg Se in Lingnan Yellow broiler breeder diets.

Biochemical factors limiting myocardial energy in a chicken genotype selected for rapid growth

Broiler chickens (Gallus gallus) genetically selected for rapid growth are inherently predisposed to heart failure. In order to understand the biochemical mechanisms associated with the deterioration of heart function and development of congestive heart failure (CHF) in fast-growing chickens, this study examined several factors critical for myocardial energy metabolism. Measured variables included cardiac energy substrates [creatine phosphate (CrP), adenosine triphosphate (ATP), l-carnitine], activity of selected cytosolic enzymes [creatine kinase (CK; EC 2.7.3.2), lactate dehydrogenase (LDH; EC 1.1.1.27)] and mitochondrial enzymes [pyruvate dehydrogenase (PDH; EC 1.2.4.1), alpha-ketoglutarate dehydrogenase (alpha-KGDH; EC 1.2.4.2)]. The CK activities were higher in fast-growing and CHF broilers as compared to slow-growing broilers (p<0.05). Cardiac LDH and alpha-KGDH activities were not changed (p>0.05), whereas PDH activity was highest (p<0.05) in broilers with CHF. Deterioration of heart function is correlated with lowered cardiac ATP, CrP, and l-carnitine levels (all p<0.05). Depletion of high energy phosphate substrates, ATP and CrP, is evident in fast-growing chickens and those that developed CHF. Increased activity of CK suggests that cardiac energy management in fast-growing broilers and those with CHF largely depends on contribution of this pathway to regeneration of ATP from CrP. In this scenario, inadequate level of CrP is a direct cause of ATP insufficiency, whereas low cardiac l-carnitine, because of its role in fatty acid transport, is most likely an important factor contributing to shortage of key substrate required for synthesis of cardiac ATP. The insufficiencies in cardiac energy substrate synthesis provide metabolic basis of myocardial dysfunction in chickens predisposed to heart failure.