Abstract in English:Egg- and meat-type quails were reared in groups of different sizes with a fixed female-to-male ratio of 2 to 1 and an area of 158 cm² per bird. The aim was to investigate the influence of group size on quail production and reproductive variables. To this end, 360 quails (180 meat and 180 egg-type quails) were assigned in a completely randomized experimental design to one of three treatments with ten replicates each. The treatments consisted of groups with nine, six, or three quails per cage. Birds were observed for three cycles of 14 days. Daily feed intake and feed conversion ratio were influenced (p < 0.05) by group size in both types of quails. Quail type influenced (p < 0.05) daily feed intake, feed conversion, and egg weight due to the typical differences between meat and egg-type birds. Despite the observed differences in production parameters, the mean values observed were typical of meat- and egg-type quails. The number of hydrolysis points (holes) per mm² on the vitelline membrane on the germinal disc area was higher in meat quails (2.89 ± 0.21) than in egg quails (2.15 ± 0.13). This parameter was not influenced by the number of birds per cage, which suggests that the number of males inside the cage did not modify the spermatozoa pool inside the female oviduct. We concluded that a ratio of two females per male in cages with three, six, and nine birds/cage is recommended, as no deleterious effect on quail reproduction was observed.
Abstract in English:In this study, the physical-chemical characteristics and proximate composition of the meat of of two strains of broilers (Paraíso Pedrês and Máster gris plumé - Super Pesadão, utilized for semi-intensive rearing) and Cobb® strain, utilized in intensive rearing systems) were evaluated. Differences related to strain and sex (males and females) were studied. Cobb® broilers were slaughtered at 45 days and the other strains at 85 days. The following characteristics were evaluated in breast and thigh meat: moisture, protein, ether extract, ashes, color (CIEL*a*b*), final pH, cooking loss (CL) and shear force (SF). Bird strain and sex influenced breast color parameters, with Cobb® presenting higher yellowness (b*) and redness (a*) means, whereas females had higher b* values and males, a* values. Paraíso Pedrês had lower SF values. As to proximate composition, there was an interaction between strain and sex, with higher ether extract values in the meat of Super Pesadão males. Cobb® birds presented higher lightness (L*) and b* values, and there was no effect of sex on color parameters. Higher pH and SF values were found in the meat of Super Pesadão birds. There was an interaction between strain and sex for b* and SF values, with higher b* values obtained with Cobb® males, while differences between sex, with superiority for females in the Paraíso Pedrês strain and for males in the Cobb® strain were found. Increased values of SF for males were obtained for Super Pesadão strain. Both Paraíso Pedrês and Super Pesadão strains presented physicochemical and proximate composition characteristics similar to those of Cobb® strain in the cuts breast and thigh so that in a few parameters, no differences between the birds kept in this two rearing systems were found.
Abstract in English:The effects of aflatoxin and fumonisin and their combination on egg production and quality, as well as the efficacy of a mycotoxin adsorbent in reducing or eliminating these effects in commercial layers. A number of 168 layers with initial age of 37 weeks were submitted to an experimental period of 56 days. A completely randomized experimental design in a 3x2+1 factorial arrangement was applied (3 treatments with mycotoxins: aflatoxin (AF), fumonisin (FU), or aflatoxin + fumonisin (AF+FU); 2 treatments with or without adsorbent; and a control group that was fed no mycotoxins, nor adsorbent), totaling 7 treatments with 6 replicated of 4 birds/cage. The dietary inclusion levels were 1ppm AF, 25ppm FU, and 2 kg adsorbent/ton feed. Birds fed AF presented the lowest percentage of lay (p=0.0594). Egg mass was the lowest (p<0.05) in the AF+FU treatment (49.49g). The treatment with AF resulted in higher eggshell thickness and strength (p<0.05) than the FU treatment and the control group. The inclusion of the adsorbent in the AF contaminated feed reduced eggshell strength, which returned to levels similar to those of the control group. The observed changes indicate that aflatoxin is toxic at a concentration of 1ppm, and that the effects of fumonisin were less evident as a function of the low dose applied. The inclusion of the glucan (2kg/ton) effectively reverted some of the toxic effects of aflatoxin and, at lower extension, those of fumonisin, when these mycotoxins were invidually added to commercial layer feeds.
Abstract in English:A total of 405 23-week-old ISA® Brown layers were distributed in a completely randomized experimental design in a factorial arrangement with nine treatments consisting of three dietary calcium levels (3.5, 3.75, and 4.5%) and three limestone particle sizes (100% fine limestone (FL), 70% FL + 30% coarse limestone (CL) and 50% (FL) + 50% (CL)), with nine replicates of five birds per cage. The following parameters were evaluated: percentage of lay, defective eggs, egg weight, egg mass, feed intake, feed conversion ratio (per kg eggs and per dozen eggs), and mortality. Dietary Ca levels significantly affected lay, with birds fed diets containing 4.5% calcium producing less eggs as compared to those fed 3.0 and 3.75% Ca. Egg production linearly decreased as dietary Ca levels increased, but blood Ca levels (mg/L) increased in 28-week-old birds. The interaction of dietary Ca levels and limestone particle sizes resulted in a reduction in tibial ash Ca content as dietary Ca levels increased and as fine limestone was replaced by coarse limestone. It is concluded that a dietary Ca level of 3.75% and 100% fine particle limestone are required to maintain adequate egg production and available Ca blood level.
Abstract in English:The objective of this study was to evaluate the internal quality of eggs of Japanese quails fed diets supplemented with chelated selenium and zinc. The experiment was carried out for 120 days, and 144 birds were divided in random blocks into four treatments (control; 0.3 ppm Se; 60 ppm Zn and 0.3 ppm Se + 60 ppm Zn). Ten, 14, 18, and 22 weeks after the beginning of lay, eggs were collected and stored under two different temperatures (environmental temperature or refrigeration) and for 10, 20, and 30 days. Eggs were analyzed for: Haugh units (HU), albumen height (AH), yolk index (YI), and albumen index (AI). Parameters were only statistically influenced by the interaction between dietary treatment and storage time. It was concluded that the addition of organic Se and Zn influenced internal egg quality when eggs were stored up to 20 days, independently of storage temperature, suggesting that the combined supplementation of organic Se and Zn improve internal egg quality and extend egg shelf life.
Abstract in English:Precise phosphorus nutrition is important for significant reductions in both P pollution and ration costs. The influence of different levels (%) of dietary nPP fed from 0 to 20 d (0.45, 0.40, 0.35, 0.30, 0.25, compared with feeding 0.20 nPP with and without 500 F.T.U. of phytase per kg of diet) and from 21 to 36 d of age (0.414, 0.364, 0.314, 0.264, 0.214, compared with 0.164 nPP with and without 500 F.T.U. of phytase per kg of diet) were evaluate using a total of 588 day-old commercial broiler chicks. Each treatment was replicated four times in a completely randomized design. Body weight (BW), daily gain (DG), feed intake (DFI), feed conversion ratio, plasma P level and bone characteristics were determined, and from these data the P equivalency of the phytase was estimated. Feeding diets containing less than 0.40% of nPP to birds between 0 and 20d resulted in inferior BW, DFI, plasma P level and bone characteristics compared with the control. However, optimum FCR and mortality was supported at lower levels of nPP (0.25%). Between 21 and 36 d, 0.364% was enough to optimise BW, DFI, and femur ash (%); whilst only 0.314% or greater was needed to support optimum DG, toe and tibia ash and only 0.214 to 0.264% was required to optimise shank, femur and tibia lengths; FCR and survivability. A broken line analysis also showed that the nPP (%) requirement ranged from 0.267 to 0.410 and 0.272 to 0.380% during 0 to 20 and 21 to 36 d, respectively. Phytase supplementation improved performance and bone criterion and its P equivalency, depending upon the response of interest and birds age, ranged from 0.00 to 0.110%. In conclusion, the results showed that the combination of a lower level of nPP and phytase may be used to increase dietary P utilization, without severe changes in performance and bone quality.
Abstract in English:Studies on the relationships between animal nutrition and immunity have sought reliable methodologies to measure responses. Cell-mediated immune response is similarly studied in humans. The cutaneous basophil hypersensitivity test (CBH) is one of the methods to measure that response and consists in the infiltration of inflammatory cells, particularly of lymphocytes and basophils, as result of the application of substances capable of inducing cell proliferation in determined sites, such as wings, wattle, and interdigital space in birds. CBH is considered a simple and fast method and can be applied in birds of different ages. In immunocompetence studies with poultry, phytohemagglutinin-P (PHA-P) is a commonly used substance, despite the variability of the response related to the method of application (intradermal injection) and the antigens used. In the present experiment, PHA-P was used to observe the cell-mediated immune response of 216 chicks fed three dietary levels of vitamin E from 1 to 36 days of age. All birds were immunologically challenged by vaccination against coccidiosis at three days of age and against Newcastle Disease (NCD) at 14 and 30 days of age. At 36 days of age, birds were submitted to the CBH test according to the methodology of Corrier & DeLoach (1990). Birds fed 65mg/kg of vitamin E presented lasting cell reaction (p<0.08), which indicates that this vitamin E level improved cell immune response of birds due to its antioxidant and immunomodulating properties. The use of this vitamin E level can be considered by nutritionists under practical conditions, aiming to improve broiler immunity.
Abstract in English:The aim of this study was to evaluate the viability of the use of spent laying hens' meat in the manufacturing of mortadella-type sausages with healthy appeal by using vegetable oil instead of animal fat. 120 Hy-line® layer hens were distributed in a completely randomized design into two treatments of six replicates with ten birds each. The treatments were birds from light Hy-line® W36 and semi-heavy Hy-line® Brown lines. Cold carcass, wing, breast and leg fillets yields were determined. Dry matter, protein, and lipid contents were determined in breast and leg fillets. The breast and legg fillets of three replicates per treatment were used to manufacture mortadella. After processing, sausages were evaluated for proximal composition, objective color, microbiological parameters, fatty acid profile and sensory acceptance. The meat of light and semi-heavy spent hens presented good yield and composition, allowing it to be used as raw material for the manufacture of processed products. Mortadellas were safe from microbiological point of view, and those made with semi-heavy hens fillets were redder and better accepted by consumers. Values for all sensory attributes were evaluated over score 5 (neither liked nor disliked). Both products presented high polyunsaturated fatty acid contents and good polyunsaturated to saturated fatty acid ratio. The excellent potential for the use of meat from spent layer hens of both varieties in the manufacturing of healthier mortadella-type sausage was demonstrated.
Abstract in English:Salmonellosis is an important disease with economic impact as it may affect animal performance and may result in foodborne disease in humans through the eggs and carcass contamination. Regarding the Salmonella control, it is possible to decrease its fecal excretion and the contamination of chicken carcasses by adding organic acids to the feed or drinking water at appropriate times. The aim of this study was to test a blend of organic acids and essential oils in broilers challenged with Salmonella Enteritidis (SE), and to verify the fecal excretion of Salmonella. Sixty broilers were placed in four groups. One group was the negative control. Another group was orally inoculated at 1 day-old with 10(5) CFU/mL of SE as a positive SE control. Two groups (T3 and T4) were orally inoculated at 1 day-old with 10(5) CFU/mL of SE and their feed was separately treated with 0.5 and 1% of organic acids and essential oils, respectively. To assess the fecal excretion of SE, cloacal swabs were collected from all birds at 2, 6, 13 and 20 days after inoculation. The T3 and T4 groups showed a reduction in fecal excretion of SE at 6 and 20 days after inoculation.
Abstract in English:The nutritional and sensorial characteristics of chicken meat can be affected by oxidative rancidity, process of oxidation of lipids in the meat that constitutes one of the main forms of food deterioration. This problem may be prevented or reduced by adding antioxidants to the meat during the process of marination. In the present study, the addition of a polyphenol-rich quillay extract (QLPerm®) at 5 levels (0, 0.05, 0.10, 0.15, and 0.20%) to the marinade of chicken meat was evaluated. The marinated meat was stored under refrigeration (6 ºC) for 0, 2, 4, 6, and 8 days. Basal and induced lipid oxidation was evaluated by TBARS analysis. Microbiological quality was assessed by total coliforms and mesophillic aerobe counts. The application of this natural antioxidant reduced, in some cases, meat lipidic oxidation, improved its microbiological quality, and did not leave any perceivable residues as analyzed by a sensorial evaluation panel.