Broilers are known as an efficient source of lean meat. Genetic selection resulted in broiler strains with large body size and fast growth, but a concomitant increase in fat deposition also occurred. Other than reducing nutrient intake, there is a lack of alternative methods to control body fat composition of broilers. The present study assessed whether incubation temperature (machine temperatures: 36ºC, 37.5ºC, and 39ºC; eggshell temperatures: 37.4 ± 0.08°C, 37.8 ± 0.15ºC, and 38.8 ± 0.33°C, respectively.) from d 13 affects broiler hatchling fat deposition. We analyzed adipocyte hypertrophy and proliferation in 3 body regions; weight and chemical composition of yolk-free chicks and yolk sacs; and serum lipid profile. Increased incubation temperature reduced abdominal and cervical adipocyte size. Independently of temperature, cervical adipocytes were smaller and showed higher proliferation than adipocytes in the abdominal and thigh regions. Smaller cervical adipocytes were observed in birds from eggs incubated at 36ºC and 39ºC. With regard to weight and composition of chicks, ash content as a percentage of dry matter was the only variable affected by temperature; it was higher in chicks from eggs incubated at 36ºC than at 39ºC and showed no significant difference between chicks incubated at 39ºC and 37.5ºC. Absolute and relative weights of yolk sacs were higher from eggs incubated at 39ºC than at 36ºC, and these two treatments did not differ from the 37.5ºC control. Absolute measures of yolk sac lipids, moisture, dry matter, and crude protein content were lower in chicks from eggs incubated at 36ºC, and no significant differences were found for these variables between chicks from eggs incubated at 37.5ºC and 39ºC. Hatchlings from eggs incubated at 36°C had significantly higher cholesterol levels than chicks incubated at the other 2 temperatures, but no additional effects on blood lipids were detected. Incubation temperature manipulation during fetal development altered cervical and abdominal adipocyte size in broiler hatchlings and could become a tool in hatcheries to manipulate chick quality, although further studies are needed to evaluate its long-term effects.

Dose-dependent positive effects on hatchability and hatchling weight have been attributed to ascorbic acid (AA) when eggs were submitted or not to intermittent heat stress during incubation. Fertile breeder (Cobb®) eggs were used to determine if the pre-incubation injection of AA in ovo affects the incubation and hatchling quality of egg incubated under thermoneutral or intermittent heat stress conditions. Eggs were not injected or injected with 0, 2,4, or 6% AA/100µL water and incubated at continuous thermoneutral (37.5ºC) or hot (39.0ºC) temperature. Eggshell temperature (EST) increased in the second half of the incubation period in all experimental groups. The EST of non-injected eggs and of those injected with water was higher when incubated at 39°C than at 37.5°C, but EST was not different among eggs injected with AA. Egg mass loss and eggshell conductance were higher in the eggs incubated at 39°C than at 37.5°C.Hatchability was lower in the eggs injected with AA. Liver and yolk sac weights were higher, whereas heart and liver weights were lower in hatchlings from eggs incubated at 39°C; however, hatchling weight was not affected by incubation temperature. The results showed that AA doses affected egg conductive heat loss and hatchability, and that they did not minimize the effects of high incubation temperature on liver and heart development.

We investigated the effects of incubation temperatures and vitamin C injections into eggs (treatments: 37.5ºC, 39ºC, 39ºC+vitamin C) on resultant chick pectoralis major and sartorius muscle fiber hypertrophy, as well as their effects on the quality of breast and over-thigh meat of broilers reared under cold, control, or hot temperatures. Incubation at 39ºC increased the shear force and reduced meat redness in breast meat (P < 0.05). Vitamin C prevented these high temperature incubation effects [shear force (kgf cm(-2)): 37.5ºC = 2.34, 39ºC = 2.79, 39ºC+vitamin C = 2.44; redness: 37.5ºC = 2.64, 39ºC = 1.90, 39ºC+vitamin C = 2.30], but reduced water content (37.5ºC = 74.81%, 39ºC = 74.53%, 39ºC+vitamin C = 69.39%) (P < 0.05). Cold rearing temperatures increased breast meat redness (a*: cold = 2.78, control = 2.12, hot = 1.98), while hot rearing temperatures reduced the muscle fiber area (cold = 5.413 μm(2), control = 5.612 μm(2), hot = 4.448 μm(2)) (P < 0.05) without altering meat quality (P > 0.05). Hot rearing temperatures increased the cooking loss (cold = 30.10%, control = 33.66%, hot = 37.01%), shear force (cold = 3.05 kgf cm(-2), control = 3.43 kgf cm(-2), hot = 4.29 kgf cm(-2)) and redness (a*: cold = 4.63, control = 3.55, hot = 3.20) in the over-thigh meat of broilers from eggs incubated at 37.5ºC, increasing the area of muscle fibers, while cold rearing temperatures diminished cooking loss and shear force, reducing the muscle fiber area (P < 0.05). Incubation at 39ºC and 39ºC+vitamin C prevented the effects of hot and cold rearing temperatures, by diminishing and increasing the muscle fiber area, respectively.

Skeletal abnormalities, bone deformities and fractures cause significant losses in broiler production during both rearing and processing. Silicon is an essential mineral for bone and connective tissue synthesis and for calcium absorption during the early stages of bone formation. Performance was not affected by the addition of silicon. However, broilers receiving silicon showed a significant increase of phosphorus, zinc, copper, manganese and ash in the tibia. In conclusion, broiler performance was not impaired by adding the tested silicon product to the drinking water. In addition, bone development improved, as demonstrated by higher mineral and ash content. Further studies are required to determine the optimal concentration of silicon, including heat stress simulations, to better understand the effects of silicon on bone development.

KeywordsRice hulls, cottonseed hulls, soybean hulls, crude protein, egg production. ABSTRACTThis study aimed at evaluating diets containing different fiber sources and two crude protein levels on the performance, egg quality, and nitrogen metabolism of commercial layers. In total, 392 48-wk-old Isa Brown layers were distributed according to a completely randomized experimental design in a 3x2+1 (control) factorial arrangement, resulting in seven treatments with seven replicates of eight birds each. Treatments consisted of three fiber feedstuffs (cottonseed hulls, soybean hulls, and rice hulls) and two dietary crude protein levels (12% and 16%). Cottonseed hulls associated with the high crude protein level (16%) resulted in the worst feed conversion ratio per dozen eggs. Diets with 16% crude protein resulted in the highest feed intake, egg production, egg weight, egg mass values, and improved feed conversion ratio (kg eggs/kg feed). The dietary inclusion of soybean hulls determined low yolk pigmentation, and of rice hulls, low egg specific gravity. The 16% crude protein diet with rice hulls promoted the best feed conversion ratio. Hens fed the reference diet presented higher egg mass and better feed conversion ratio per kg eggs and per dozen eggs. Hens fed the diets with low crude protein level (12%) had reduced nitrogen excretion, but presented worse egg production.

This study aimed to identify the influence of climate pattern and rearing conditions on broiler carcass condemnations observed during processing. We evaluated the registered data of 2015 from the federal inspection files in all broiler slaughterhouses located in the state of Mato Grosso do Sul, Midwestern Brazil. The percentages of condemnations by airsacculitis, cellulitis, dermatosis, ascites syndrome, total carcass condemnations, and average broiler weight at 42 days were analyzed. Data were associated with housing systems and season of the year in which each flock was reared. Two-way ANOVA was applied to the data in a completely randomized design 4×3 (four seasons and three houses) and compared by Tukey's test. The results indicated that the housing system did not affect the studied condemnations, and seasons of the year did not change condemnation by airsacculitis; however, the other pathologies leading to carcass condemnations were affected by season. Condemnations by cellulite were higher during summer than in winter. For dermatosis, the maximum index appears during summer and the lowest during winter and spring. The ascites syndrome presented the smallest index in summer and winter, and the minimum value was found in spring. The average bird weight was higher in autumn than in winter and spring. Type of broiler rearing did not affect the carcass condemnation index. Summer was the most detrimental period regarding the condemnation rates for the pathologies studied, mainly cellulitis and dermatosis, while the highest average weight of birds was found during autumn and spring.

This experiment was carried out to evaluate the effects of the inclusion of different levels of phytase on broiler performance, bone densitometry, and phosphorus and nitrogen excretion. Nine hundred and sixty one-day old broilers, 50% males and 50% females, were distributed in a completely randomized experimental design into five treatments and six replicates 32 birds each. The treatments consisted of a control diet and four diets with the addition 25, 50, 75, and 100 g/ ton of phytase (250, 500, 750 and 1000 FTU of phytase/kg fed). Diets were formulated to contain equal nutritional levels, and considered the phytase product nutritional levels. In general, the addition of phytase resulted in a linear decrease in broiler performance. However, the performance results obtained with the level of 250 FTU phytase/kg feed were not different from the control treatment. The best bone density results were observed in the control treatment, with no phytase. The results of this experiment indicate that the nutritional matrix of the phytase product needs to be reviewed when added in levels higher 250 FTU/kg to broiler diets. INTRODUCTIONAiming at lowering production costs, many current research studies have focused on improving the efficiency of feedstuff utilization and to reduce the impact of animal production on the environment (Payne et al., 2005).Phosphorus is one of the most expensive nutrient of poultry and swine feeds, second only to energy and protein (Borges, 1997). It is nutritionally essential, as shown by its several roles in the body, and it is particularly important during growth. However, two thirds of the phosphorus contained in cereal grains and oil seeds are in the form of phytate, which can bind to other nutrients, rendering them unavailable for poultry and pigs, thereby, requiring dietary inorganic phosphorus supplementation (Denbow et al., 1995).The production of industrial phytase is based on microorganisms, using DNA recombination techniques. This enzyme increases phosphorus (P) availability in plant feed ingredients, where P is usually present as phytate. The dietary supplementation of phytase allows poultry and pigs to more efficiently absorb phosphorus, reducing the amount of inorganic phosphorus supplementation, and promoting better weight gain, feed conversion ratio, feed intake, and bone mineralization, as well as reducing mortality (Qian et al., 1996).Along with calcium, phosphorus has an essential role in bone formation. In the animal, phosphorus comprises about 1% of live weight, and it is carefully considered when feeds and supplements are formulated. About 80% of phosphorus in the animal body is deposited 26in bones and teeth. Therefore, the inclusion of phytase in broiler diets may enhance their bone development. The objectives of the present study were to evaluate the effects of the inclusion of different levels of phytase on broiler performance, bone densitometry, and phosphorus and nitrogen excretion in the litter during the starter (1 to 21 days), grower (22 to 42 days), and t...

-The objective of this study was to evaluate the effect of chamomile extract on Japanese quail on their performance, animal behavior, tonic immobility, body injuries, and surface temperature. The trial was conducted using 108 quail distributed in a completely randomized experimental design, with three treatments (0, 2.5, and 5.0 g chamomile/kg of feed), six replicates, and six birds per treatment, evaluated in six measures repeated in time (14, 28, 42, 56, 70, and 84 days of trial). The inclusion of chamomile presented a quadratic effect on sitting behavior, estimating the inclusion of 1.8 g chamomile/kg to maximize this behavior. There was a decreasing linear effect for aggressive pecking, that is, the higher the inclusion of chamomile in the diet, the lower the expression of this behavior. The inclusion of 1.8-5.0 g chamomile/kg in a Japanese quail diet reduces the behavior of aggressive pecking, in addition to keeping the birds seated longer. These results are innovative because they show in the literature for the first time that chamomile supplemented in Japanese quail diets has the capacity to modulate the behavior of the quail, leading to an improvement in the welfare of quail raised in cages.