Abstract in English:Poultry meat can be contaminated with a variety of microorganisms, including those capable of spoiling the product during chill storage, and certain foodborne pathogens. Human illness may follow from handling of raw meat, undercooking or mishandling of the cooked product. While Salmonella and Campylobacter spp. remain the organisms of greatest global concern in this respect, others present include the more recently reported Arcobacter and Helicobacter spp. and, occasionally, verotoxigenic Escherichia coli. Also considered here is the growing problem of antimicrobial resistance among poultry-associated pathogens. Because of the need for a systematic and universally applicable approach to food safety control, the Hazard Analysis Critical Control Point (HACCP) concept is increasingly being introduced into the Poultry Industry, and Quantitative Risk Assessment (QRA) is being applied to microbial hazards. Among a number of completed and on-going studies on QRA are those undertaken by FAO/WHO on Salmonella and Campylobacter in broilers. In the case of Campylobacter, however, any QRA must assume at present that all strains have the same pathogenic potential for humans and comparable survival capabilities, even though this is unlikely to be the case. Implementation of the HACCP system in poultry processing plants addresses zoonotic agents that are not detectable by conventional meat inspection procedures and can help to control contamination of carcasses with spoilage organisms. The system brings obvious benefits in optimising plant hygiene, ensuring compliance with legislation and providing evidence of 'due diligence' on the part of the processor. It is now being applied globally in two different situations: in one, such as that occurring in the USA, carcass contamination is clearly reduced as carcasses pass through the process and are finally chilled in super-chlorinated water. There is also the option to use a chemical-rinse treatment for further reduction of microbial contamination. In the second scenario, processors in the EU are not allowed to super-chlorinate process water, and water chilling, which has an important washing effect, is confined to carcasses intended for freezing. Also, chemical decontamination is prohibited until 2006 at the earliest. Therefore, for fresh carcasses that are air chilled, there is presently no marked reduction in carcass contamination and no Critical Control Point at which a significant reduction in pathogen contamination can be guaranteed. Overall, effective control of the organisms is best realised through a farm-to-fork approach at all stages of the supply chain.
Abstract in English:An experiment with 400 one-day-old male chicks (Ross) was conducted to evaluate the effects of different Na levels (0.10, 0.22, 0.34 and 0.46%) and different cation/anion balances (Na+K-Cl) (100, 150, 200, 250 and 300 meq/kg) in pre-starter diets on broiler performance. The corn and soybean-based diets had 22% crude protein and 2,900 kcal/kg metabolizable energy and were fed ad libitum. Performance data showed a positive quadratic effect of increasing Na levels on feed and water consumption, weight gain and feed conversion. Na+K-Cl also had a quadratic influence on feed intake and weight gain. None of the effects tested affected the amount of water measured in excreta. Derivatives of obtained regression equations pointed to optimal Na levels of 0.45% for water consumption, 0.40% for feed intake and weight gain and 0.38% for feed conversion. As to the effect of dietary Na+K-Cl balances on performance, regression equation values were 174 meq/kg for feed consumption and 163 meq/kg for weight gain. These results show that both Na level and Na+K-Cl balance interfere on broiler performance.
Abstract in English:There are some evidences described in the literature showing reduced energy metabolizability of ingredients for newly hatched chicks. Hence, a metabolism trial was carried out with the objective of determining the metabolizable energy of corn grain, soybean meal and micronized full fat soybean for newly hatched chicks. The method of total excreta collection was used in an experiment with 192 male chicks from one to seven days, distributed in a completely randomized design with four treatments and four replicates of twelve birds. Excreta were collected from four to seven days of age. The treatments included a reference diet, two test-diets consisting of 60% of the reference diet and 40% of the test ingredients: corn grain (CG) and soybean meal (SM), and one test-diet consisting of 80% of the reference diet and 20% of micronized full fat soybean (MFFS). The N-corrected apparent metabolizable energy (AMEn) and the metabolizability coefficient of gross energy (MCGE) of the ingredients determined for the chicks were respectively 3,213 kcal/kg and 81.6% for CG; 2,085 kcal/kg and 49.7% for SM and 4,068 kcal/kg and 74.8% for MFFS.
Abstract in English:The aim of this study was to compare performance and carcass characteristics of broilers fed diets with different Dietary Electrolyte balances (DEB) during the summer season. A total of 1,280 one-day-old Ross sexed chicks were distributed in 32 experimental units according to a randomized block design in a 4x2 factorial arrangement (4 levels and 2 sexes) and 4 replicates per treatment (40 birds per replicate). Feed program consisted of 3 phases (1-21, 22-42, 43-49 days of age). Experimental diets were formulated based on corn and soybean meal and adjusted to 210, 250, 290 and 330 mEq/kg of Na + K - Cl through the addition of sodium carbonate, potassium carbonate and ammonium chloride. Weekly measurements of body weight gain and feed intake were done, and at 49 days, birds were slaughtered to evaluate the dressing percentage and parts yield. Weight gain during the starter phase increased linearly (p<0.01) as DEB increased. Different DEB levels did not affect feed intake or mortality. Carcass characteristics were not affected by treatments. Dietary electrolytic balance influenced weight gain and feed gain ratio from 1 to 21 days, and best results were observed when diets contained 290 and 330 mEq/kg.
Abstract in English:A study with 2,400 broilers was carried out to compare the effect of the use of mannanoligosaccharides, Saccharomyces cerevisiae cell wall or growth promoter (Olaquindox) in the diet on broiler. Diets were based on corn and soybean meal. A completely randomized experimental design was used, and the obtained data were evaluated by analysis of variance and test of Tukey at a level of 5%. The following parameters were measured: feed intake, daily weight gain, feed conversion ratio, and mortality. It was concluded that the effect of the inclusion of mannanoligosaccharides in the diet on the studied parameters was significantly higher as compared to the inclusion of cell wall or to the control diet, but the effect was not different as compared to the inclusion of growth promoter.
Abstract in English:This study aimed to evaluate the effects of probiotics and prebiotics of bacterial and yeast origin on the performance, development of the digestive system, carcass yield and meat quality of free-range broiler chickens. Five hundred and sixty male chicks of the strain ISA S757-N were reared from one to 84 days old. The birds were distributed in four treatments according to a completely randomized block design: T1 = Control, T2 = Probiotics and Prebiotics of bacterial origin, T3 = Probiotics and prebiotics of yeast origin, T4 = Probiotics and prebiotics of bacterial origin + probiotics and prebiotics of yeast origin. There were four repetitions with 35 birds per repetition, and the birds had access to a pasture area after 35 days of age. Characteristics evaluated were performance, development of the digestive system, carcass and parts yield, abdominal fat, breast meat physical measurements (length, width and height) and meat quality parameters (pH from breast and leg meat, cooking loss and shearing force from breast meat). Lower mortality (p<0.05) and higher weight gain from 64 to 77 and 64 to 84 days of age were seen in birds supplemented with probiotics and prebiotics of bacterial origin compared to the non-supplemented birds (control). There were significant differences (p<0.05) among treatments for carcass yield. Birds supplemented with both probiotics and prebiotics of microbial and yeast origin (T4) showed higher carcass yield than control birds. Supplementation with probiotics and prebiotics of bacterial origin (T2) or the supplementation of these together with those of yeast origin (T4) reduced mortality and increased the carcass yield in free-range broiler chickens.
Abstract in English:The effect of three different lipid sources (soybean oil, chicken oil or bovine fat) on the abdominal fat fatty acid composition in 50 day-old broiler chickens was evaluated. A completely randomized design was used, with 4 treatments, 8 repetitions and 40 Arbor Acres broiler chicks of each sex. The four treatments were isocaloric and isoproteic with the following characteristics: T1 Control (Soybean-corn); T2 Control + 3% soybean oil; T3 Control + 3% chicken oil; and T4 Control + 3% bovine fat. The lipids from the diets had significantly statistical effects (p<0,05) on the fatty acid composition of broiler abdominal fat. Multivariate techniques also showed differences in fatty acid composition within treatments due to sex. The studied dietary lipids affected the polyunsaturated/saturated fatty acid ratio (P/S) but had only small effects on the n-6: n-3 fatty acid ratio.
Abstract in English:This study evaluated the effect of different probiotics and prebiotics on the performance of broilers. One-day-old male broiler chicks from the Cobb strain (n=1,260) were randomly distributed in a 3 x 3 factorial arrangement, considering 3 probiotics and 3 prebiotics sources. Nine treatments with 4 repetitions and 35 birds per parcel were used. The results showed that there was no influence of treatment on feed intake at the different rearing phases. Better weight gain (p<0.05) was seen when diet was supplemented with the phosphorylated mannanoligosaccharide-based prebiotic (MOS) compared to diets without prebiotics. Feed conversion of birds fed diets with probiotics and prebiotics was better than feed conversion of birds not receiving such additives. Such better results were seen in the initial period (1 to 21 days), but not in the following period (1 to 35 days) or in the total period (1 to 42 days). Better rearing viability was seen when MOS was used together with organic acidifier when compared to the diets without prebiotic. Viability was worst when no prebiotics or probiotics were used. It was concluded that beneficial effects were seen in performance of birds at 21 days when the growth promoters were used, but not at 42 days of age. Nevertheless, there was better growth viability at 42 days of age when growth promoters were added.
Abstract in English:Hy-Line W36 hens were fed diets containing zero or 6% corn oil (CO) from 26 to 38 wk of age. At 38 wk, the hens receiving the diet with 6% CO were divided into three groups. One group continued to receive the diet with 6% CO. The level of CO in the diet was reduced to zero or 3% in the other two groups. The hens previously fed the diet without CO continued to receive the control diet. Egg weight was significantly heavier when the diet contained 6% CO and was not significantly reduced when the level of CO was reduced to 3%. Egg weight from control hens was significantly lower than the EW from hens that had received CO in the diet until 38 wk but none thereafter. Hens fed the diet with CO consumed more energy than hens fed the control diet. However, when CO level was reduced to zero at 38 wk, the hens consumed less energy than hens fed the control diet. These findings indicate that the hen cannot adjust feed intake with diets based on changing energy concentration in the range from 2,783 to 3,089 kcal/kg.
Abstract in English:This study evaluated alterations in the qualitative cellular profile of leukocytes caused by the administration of low doses of ochratoxin-A (OTA) in poultry. Sixty chicks were separated in three experimental groups: control, PBS-treated and OTA-treated. Blood smears from all birds were analyzed three and six hours post-treatment. Differential leukocyte counting demonstrated that OTA reduced the percentage of lymphocytes and eosinophils and significantly increased the number of heterophils and monocytes.