Resumo em Inglês:

Infectious laryngotracheitis (ILT) herpesvirus continues to cause outbreaks of respiratory disease in chickens world-wide. Sporadic cases of ILT occur in all classes of birds, including hobby/show/game chickens, broilers, heavy breeders, and commercial laying hens. These epornitics of ILT tend to occur where there are large populations of naïve, unvaccinated birds, i.e., in concentrated areas of broiler production. ILT virus can be transmitted through (a) chickens with acute upper respiratory tract disease, (b) latently infected "carrier" fowls, and (c) fomites and contaminated persons. Chicken flocks which are endemic infected with ILT virus occur only in some regions of countries or even in particular multiple-age production farms. In these cases modified live vaccines are actually used, even though these biological products, as well as wild ILTV strains, can establish latent infections. In the case of heavy breeders and laying hens, which are typically vaccinated against ILT, sporadic cases are often related to errors in vaccine application and to biosecurity failures.

Resumo em Inglês:

The aim of this work was to evaluate sex effect on behavior of two commercial broilers lines. Productive parameters, carcass composition and yield, amount and quality of fat deposited in the meat and skin and total body fat were studied. A completely randomized design with four treatments (MR-Male Ross, HR-Female Ross, MAF-Male Avian Farm and HAF-Female Avian Farm) and eight repetitions of 40 chickens was used. Animals received water and food ad libitum. After 50 days, two birds (a male and a female) per repetition were chosen at random and slaughtered for carcass evaluation. Samples of breast, leg, skin and abdominal fats were analyzed to determine the percentage of intramuscular fat, total cholesterol and fatty acid composition. The Ross line showed higher final weight and weight gain, better intake and feed conversion rate. Also, it was observed that females of both lines had similar results in relation to these parameters. Better yield of breast with bone was found in Ross males and females. In relation to legs and thigh, Ross males showed better results and no differences were observed among females of both lines. Males deposited less fat than females. Finally, differences in percentage of intramuscular fat, content of cholesterol in breast with skin, leg with skin and skin, percentage of saturated, mono and polyunsaturated fatty acids were observed between sex and lines.

Resumo em Inglês:

Two paternal broiler lines (LL and LLc, originated from the same stock in 1998) of Embrapa Suinos e Aves genetic program were used. Line LL had been selected for eight generations for rapid growth while LLc had been mated randomly, without selection, as a control line. In the last generation, 30 males and 240 females were used in hierarchical matings with pedigree control to determine sire effect. The same number of birds were used, but matings were at random for LLc. Eggs of both lines were incubated and embryos were collected in different development stages (40, 45, 50, 55 and 60 hours after setting) in order to determine somite number (NOS). The number of evaluated embryos were 1,967 and 498 for LL and LLc, respectively. This study aimed to determine the changes in somite formation during embryonic development that resulted from artificial selection for heavier body weight. In the evaluated generation, the differences for body weight, feed conversion ratio, carcass and breast yields between LL and LLc were 546 g; 0.16 FC units, 2.20 and 2.19%, respectively. NOS was greater in the initial (40 h) and in the final (60 h) stages for LL and in the intermediary stages (45, 50 and 55 h) for LLc, indicating significant differences in the mechanisms of somite formation and development. Considering that both lines had the same genetic origin, such deviation indicates genetic changes due to artificial selection for body weight. The heritability estimates indicated low additive genetic effect for NOS in the different stages. Since the alterations were due to artificial selection for body weight, one could consider the hypothesis of using such genetic marker throughout family selection.

Resumo em Inglês:

The objective of this trial was to evaluate the effect of sunflower seed inclusion (0, 1.4, 2.8, 4.2 and 5.6%) in a laying hen diet containing corn, soybean meal, wheat meal and soybean oil as main ingredients on performance and egg quality. The evaluated variables were daily feed intake, average egg weight, feed conversion (kg.kg-1 and kg.dz-1), eggshell percentage, yolk color and Haugh unit. One hundred and sixty 25 week-old Lohmann laying hens were used in a completely randomized design with five treatments and four replications of eight birds per experimental unit. Four periods of 28 days were evaluated during 112 days. The inclusion of sunflower seed in the diet had no effect on production parameters during the experimental period. Thus, can be concluded that sunflower seed might be used at concentrations up to 5.6% in laying hen diets without affecting performance and egg quality.

Resumo em Inglês:

Crop is a known source of Salmonella contamination during broiler carcass processing. The effect of drinking water acidification by lactic acid or citric acid or a combination of those with cupric sulfate and d-limonene in the reduction of Salmonella Enteritidis (SE) recovered from the crop of broilers was evaluated. Treatments were administered during 8 hours of preslaughter fasting period (Experiments I and II) and during the last 32 hours of preslaughter (Experiment III). It was observed that acidification reduced water intake when treatments began at preslaughter feed withdrawal, and affected the possible reducing effect of these acids on SE recovering (Experiments I and II). Water intake during preslaughter feed withdrawal was not affected when treatment began 32 hours before slaughter (Experiment III). Treatments reduced SE recovering from crop (p<0.05). In Experiment III, 0.470% of lactic acid reduced the number of recovered SE in 99%. This study suggested that the addition of organic acids in the drinking water 24 hours before beginning the preslaughter feed withdrawal might reduce crop SE colonization and might be an important strategy to reduce SE contamination of broiler products during processing.

Resumo em Inglês:

One thousand two hundred and ninety six Arbor Acres females and 144 males were used to study the influence of feeding time on sexual maturity and carcass composition. Treatments were: T1 = feeding at 6:30 am, T2 = 50% feeding at 6:30 am and 50% at 3:30 pm (dual), T3 = feeding at 11:00 am, T4 = feeding at 3:30 pm. Nutrition and management were as recommended to the commercial line. Variables studied were: sexual maturity at 5% production (SM), mean egg production percentage (PEP) body weight (BW), carcass composition, tibia weight (TIBW) and tibia calcium (Ca) and phosphorus (P) contents. Analysis of variance was used, and the means were compared using Student's t test. T2 females reached SM at 25.92 weeks, which was earlier (p<0.01) than the other treatments. PEP was greater (p<0.01) for T1 and T2 than for the other treatments. BW was greater in T1 and smaller in T4 (p<0.05) than in the other treatments. TIBW was greater in T3 than in T1 and T2 (p<0.05), with no effect (p>0.10) on carcass dry matter (DM), ether extract (EE), crude protein (CP) and ash (ASH). DM, EE, TIBW, Ca and P increased (p<0.05) whereas CP and ASH decreased with age. Time of feeding influenced body weight, but not carcass composition. Hens fed twice a day had earlier sexual maturity and similar egg production compared to those fed once at 6:30 am.

Resumo em Inglês:

The performance of Arbor Acres broiler breeders (1,296 females; 144 roosters) was evaluated when submitted to the following treatments (T): T1 = feeding at 6:30 a.m. (control); T2 = 50% feeding at 6:30 a.m. and 50% at 3:30 p.m. (dual feeding); T3 = feeding at 11:00 a.m.; and T4 = feeding at 3:30 p.m. Treatments were randomly distributed in 48 pens. There were 27 females and 3 males in each pen and 12 repetitions per treatment. Nutrition and management were as recommended for the commercial strain. It was evaluated age at first egg (AFE), total egg production (TEP), number of days with production above 80% (DAP80), laying peak (P), female mortality (MOR), and gross profit margin (GM) per hen. Data were submitted to analysis of variance and means were compared by Student's t-Test. TEP of T1 (186.3±2.3) and T2 (186.5±1.5) were higher (p<0.05) than that of other treatments. TEP of T3 (177.2±2) was the smallest (p<0.05), probably due to the less significant values of DAP80 (18.9±6.0 days) and P (81.36±0.95%). AFE was earlier (p<0.05) in T2 birds. Mortality was similar (p>0.10) among treatments. GM per hen was better (p<0.05) in T1 and T2 hens. Control and dual treatments were more efficient than other treatments. It was concluded that it is possible to change conventional feeding management's by the dual feeding system.

Resumo em Inglês:

The experiment was carried out to verify if total cholesterol, HDL-cholesterol and triacylglicerol plasma levels are affected when laying hens are fed rations containing different dietary oil sources. One hundred sixty 50 week-old hens, assigned to four treatments with five replicates using 8 hens per replicate were used. The experimental period was of 84 days divided in 3 cycles of 28 days each. In the last day of each cycle, blood samples of 2 hens per replicate were randomly choose and blood samples were collected. On the other hand, blood was also collected at 7 am, 11 am and 3 pm aiming to study the daily changes of these lipids. Blood lipid parameters were not affected by different dietary oil sources (p > 0.05); however, HDL-cholesterol did change during the day, giving evidence that this lipid is indeed involved in the egg yolk formation.

Resumo em Inglês:

The present work evaluated the effect of different probiotics on carcass and meat quality of broilers. One thousand and fifty male Cobb chicks were distributed at one day of age in a randomized design with 3 x 2 + 1 factorial arrangement (3 probiotics, 2 levels of probiotics in drinking water and 1 negative control group), using 5 replications with 30 birds. Carcass yield was higher (p<0.05) in control birds. Nevertheless, the groups fed with probiotics showed higher (p<0.01) leg yield at 45 days of age. There was a significant decrease in color (lightness) and increase in pH of breast muscle 5 hours after slaughter in the probiotics treated birds. In the sensory analysis, meat flavor and general aspect 72 hours after slaughter were better when probiotics were added in both water and diet. There were no differences in water holding capacity, cooking loss and shearing force among different probiotics or between them and the control. Thus, meat quality was better when probiotics were fed in the water and diet instead of only in the diet. Nevertheless, carcass and meat quality showed no alteration when the control group was compared to birds fed with probiotics, except for leg yield improvement in the latter.