Influence of sulfur amino acid levels in diets of broiler chickens submitted to immune stress

Abstract

Several changes in amino acid levels occur during an infection. As a rule, glycine, taurine and serine levels diminish considerably, while cysteine levels increase. Such changes may be attributed to the intense consumption of sulfur amino acids (SAA- methionine+cysteine) during infectious challenge. Methionine plays an important role in humoral and cellular immune responses. It has been suggested that such effect is exerted by intracellular glutathione and cysteine levels. Four-hundred thirty-two day-old Ross male broiler chickens were fed (from 1 to 42 days of age) three SAA levels in the diet (0.72, 0.82, and 0.92% from 1 to 21 days of age; 0.65, 0.75, and 0.85% from 22 to 42 days of age) and submitted to two immunological stimulus series. Vaccines against Marek's disease, Fowlpox, Infectious Bronchitis and Infectious Bursal disease, Freund's Complete Adjuvant, and avian tuberculin were used as immunological stimuli. The experiment comprised 6 treatments, with 6 replications using 12 birds per replicate. Performance data were collected weekly. Gumboro antibodies were measured by ELISA, and the cellular immune response by the tuberculin test. SAA levels tested did not influence immune response. Nevertheless, the vaccines applied on the 1st day impaired chick performance up to the 21 days of age. The SAA levels generally adopted in poultry husbandry may not be enough to assure weight gain, especially when birds are raised if a low-challenge infectious environment

Estimation of dietary lysine requirement based on broken line and quadratic model analyses with the use performance and immune responses criterion

“…The resistance against infectious challenges requires an intense response orchestrated by the immune system. From the nutritional standpoint, feed substrates (AAs, energy and enzymes) are needed to activate such a response (Rubin et al 2007). Minimum requirements for a given nutrient for maximum production are fully established (NRC 1994).…”

The Effect of Methionine and Threonine Supplementations on Immune Responses of Broiler Chickens Challenged with Infectious Bursal Disease

“…Methionine plays an important role in humoral and cellular immune responses (Swain and Johri, 2000;Shini et al, 2005). It has been suggested that such effect is exerted by intracellular glutathione and cysteine levels (Rubin et al, 2007). One of the mechanisms proposed to explain methionine interference in the immune system is based on the proliferation of immune cells, which are sensitive to intracellular variations in glutathione and cysteine levels, compounds which also participate in the metabolism of methionine (Shini et al, 2005).…”

Estimation of dietary threonine requirement for growth and immune responses of broilers

“…The resistance against infectious challenges requires an intense response orchestrated by the immune system. From the nutritional standpoint, feed substrates (amino acids, energy and enzymes) are needed to activate such a response (Rubin et al 2007). Minimum requirements for a given nutrient for maximum production are fully established (NRC 1994).…”