The present study aimed at assessing the effects of methionine and arginine on the immune response of broiler chickens submitted to immunological stimuli. Three methionine concentrations (0.31, 0.51, and 0.66% from 1 to 21 days of age; 0.29, 0.49, and 0.64% from 22 to 42 days of age) and 2 arginine concentrations (1.33 and 1.83%; 1.14 and 1.64% for the same life periods) were tested. Birds were divided into two groups for immunological stimuli (3x2x2 arrangement). Vaccines against Marek's disease, fowl pox, infectious bronchitis, Freund's Complete Adjuvant, Sheep red blood cells (SRBC), and avian tuberculin were administered to one group as immunological stimuli; the other group did not receive any stimulus. The experiment was carried out with 432 one-day-old male Ross broilers, distributed into 12 treatments with 6 replicates of 6 birds each. Performance data were weekly collected. Anti-SRBC antibodies were collected by hemagglutination test and cell immune response (CIR) was measured by tubercularization reaction in one wattle 24 hours after administration of the second tuberculin injection at 42 days of age. The weight difference between the two wattles of each bird (one injected with tuberculin and the other not) was the measure of CIR. Arginine levels did not influence either bird performance or immune response. Methionine concentrations higher or lower than usually adopted in broiler production (0.51 and 0.49%) equally failed to influence the birds' immune humoral response, but the best CIR was observed at the intermediate methionine level. Vaccines administered on the first day of age impaired bird performance up to the 21st day of age

RESUMO Estudou-se o uso do ácido butírico (AB) e da fitase em dietas de suínos na fase de crescimento, variando no nível de cálcio. O experimento foi subdivido no tempo em dois

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

One to 42-d-old (432) female broilers were fed different levels of inorganic selenium (ISe) and organic selenium (OSe), according to the following treatments: (1) 0.3 mg ISe; (2) 0.3 mg ISe + 0.2 mg OSe; (3) 0.5 mg ISe and (4) 0.3 mg OSe/ kg of feed. All birds were vaccinated against infectious bursal disease (IBD) at 19d of age and three birds/replicate (R) were inoculated with sheep red blood cells (SRBC) at 32d. Three other birds/R received Freund's adjuvant at 37d and avian tuberculin (AT) in the wattle at 47d of age. All birds were submitted to heat stress after 21d. Performance parameters, bursa and spleen weights, lymphocyte bursa depletion, antibody (Ab) production against IBD and SRBC, hematocrit, leukocytes, heterophil/lymphocyte ratio (H/L), and cellular reaction to AT were evaluated. The contrast analysis showed that OSe has improved feed intake (FI) between day 1 and 42 (p<0.10). Birds fed ISe presented worse H/L ratio (p<0.10), but higher Ab titers against IBD (p<0.04) and SRBC (p<0.05) than birds fed OSe, but OSe supplemented birds showed lower lymphocyte depletion scores in the bursa. The higher FI promoted by OSe may be beneficial when rearing broilers in hot weather. The use of ISe induced higher humoral immune respons

In this study, Hisex Brown layers in lay were evaluated between 40 and 44 weeks of age to evaluate the inclusion of bacterial phytase (Ph) and sodium butyrate (SB) to diets containing different calcium levels (CaL). Performance, average egg weight and eggshell percentage, in addition to nutrient metabolizability and Ca and P balance were evaluated for 28 days. Birds were distributed according to a completely randomized experimental design with a 3x2x2 factorial arrangement, with three calcium levels (2.8, 3.3, 3.8%); the addition or not of phytase (500PhU/kg) and the addition or not of sodium butyrate (20mEq/kg), composing 12 treatments with eight replicates of one bird each. There was no additive effect of phytase or SB on the evaluated responses. Feed intake and feed conversion ratio were influenced by CaL, with the best performance obtained with 3.3% dietary Ca. Ca balance was positively affected by dietary Ca, and P balance by the addition of phytase. Ca dietary concentration, estimated to obtain Ca body balance, was 3.41%, corresponding to an apparent retention of 59.9% of Ca intake.

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