BackgroundChickens are animals that are sensitive to thermal stress, which may decrease their production level in terms that it affects feed intake and thus, decreasing body weight gain. The Heat Shock Factors (HSF) and Heat Shock Proteins (HSP) genes are involved in the key cellular defense mechanisms during exposure in hot environments. Aimed with this study to analyze the expression of HSF1, HSF3, HSP70 and HSP90 genes in two local breeds (Peloco and Caneluda) and a commercial broiler line (Cobb 500®) to verify differences in resistance of these chicken to Heat stress treatment. Chicken were submitted to heat stress under an average temperature of 39°C ± 1.ResultsUnder stress environment, the HSP70 and HSP90 genes were more expressed in backyard chickens than in broiler. There was a difference in HSP70 and HSP90 expression between Caneluda and Cobb and between Peloco and Cobb under stress and comfort environment respectively. HSP70 expression is higher in local breeds during heat stress than in a commercial broiler line. No significant differences were observed in the expression of HSF1 and HSF3 genes between breeds or environments.ConclusionsHSP70 and HSP90 genes are highly expressed, HSF1 and HSF3 genes did not have high expression in all genetic groups. HSP70 and HSP90 are highly expressed in Peloco and Caneluda within heat stress, these breeds proved to be very resistant to high temperature.

The objective of this study was to conduct a systematic review of the literature on the use of phytogenics in broiler nutrition. A bibliographic survey was conducted for the years between 2009 and 2019, using the keywords “eubiotics,” “phytobiotics,” “essential oils,” “phytogenic extracts,” and corresponding words associated with the terms “broiler” and “poultry.” The selected articles were grouped into the categories: animal performance, histomorphology of the intestinal wall, biochemical profile, carcass characteristics, and the effect on bacteria found in the intestine. After comparisons of several parameters on the use or non-use of phytogenics, it was found that replacing antibiotics with phytogenics contributes positively to performance, the histomorphology of the intestinal wall, the biochemical profile, carcass characteristics, and the number of bacteria found in the gut. In conclusion, based on several studies found in the literature, replacing antibiotics with phytogenic additives in broiler nutrition may be viable due to their lower residual impact on the final product, in addition to their positive effect on the parameters of animal production.

The increase in CO 2 emissions from anthropogenic sources may not only result in temperature increase on a global scale but also in increased ocean acidification (OA), by lowering the ocean's capacity to absorb additional atmospheric CO 2 . As a consequence, changes in ocean chemistry are prone to occur through the imbalancing of sea-atmosphere [1,2] gas exchange, thus affecting O 2 absorption as well.There are many studies on the potential effects of OA and increased ocean temperatures on the physiology of marine organisms but little is known about changes at histological level and there are still several gaps at molecular level which must be studied for a better understanding of all biological mechanisms involved. With regard to hypoxia, alterations to the stress response can provide information on the organisms' physiological effects and coping strategies triggered by anoxia. For instance, it is known that organisms respond by reducing protein synthesis [3,4]. Once temperature affects physiological, behavioral and ecological processes, there is a need to understand what mechanisms are behind the organisms' response to stress, enhancing our predictive and environmental management capacities considering a climate change scenario. This is of great importance, in particular to countries with a sea-based economy.The aim of the present study is to assess the stress response of a marine fish, sea bream (Sparus aurata) exposed to increasing water temperature and different water acidity (alone or in combination). Here we present preliminary data on temperature effects on S. aurata at a cellular and molecular level. In addition, tissue samples from muscle, livers, gills and intestine are examined to evaluate any alterations caused by altering this physical parameter.Fish were distributed randomly in tanks (n=96) and allowed to acclimate at 18ºC (the same temperature of the hatchery) before the beginning of the bioassays. After assessment of the upper thermal limits (UPL), water temperature was increased at a rate of 1ºC per hour using a thermostatized bath with a constant rate of watertemperature until reaching the endpoint, following the dynamic method of Critical Thermal Maximum (CTM) [5]. Every 2ºC step, fish were euthanized by cervical transection and the selected organs removed and stored at -80ºC until further analysis. Sub-samples were taken and processed for histological examination following standard techniques [6]. Frozen samples were analysed for heat stress proteins (HSP70) as described by Madeira et al. [7]. The histological observations were carried out using a Leica microscope (DMLB model). Preliminary results of the histological examination showed changes in the cellular structure, with visible damage at higher 83

Determine levels of digestible lysine for free-range chicken of the Caneludo Catolé, during the initial, growth and termination  phases. Were used150 male and female poultry in confinement cages. The digestible lysine levels used per phase: initial (1-30 dias) 0.856, 0.978, 1.100, 1.223, 1.345%, growth (30-75 dias) 0.705, 0.806, 0.906, 1.007, 1.108% and  termination (75-105 dias)  0.624, 0.713, 0.802, 0.891, 0.980%. Five treatments, three replicates, 10 chickens per experimental unit, distributed in a completely randomized design. Parameters of zootechnical evaluated: feed intake, weight gain, feed conversion ratio. The carcass characteristics evaluated: carcass, breast, drumstick, thigh, wing, neck, back, foot, gizzard, liver and heart yields. Meat quality evaluated: pH, shear force (kgf/g), cooking weight loss (%).The levels of digestible lysine influence in the initial phase with quadratic effect (P<0.01) in weight gain  1.225% and feed conversion ratio 1.175%. In the growth phase digestible lysine had a positive linear on feed intake (P<0.05) and weight gain (P<0.01) and linear decrease (P <0.01) for feed conversion ratio. In the termination phase, feed intake linearly increased (P<0.05), weight gain and feed conversion were quadratic (P<0.01), with levels calculated as 0.757 and 0.713%, respectively. Increasing linear responses were observed for carcass (%), breast (P<0.05) and drumstick (P<0.01) yields. The pH of the breasts showed a linear increasing effect (P<0.01), while shear force and cooking weight loss had a linear decreasing effect (P <0.01) with the increase of digestible lysine levels. The levels of digestible lysine recommended per phases: 1.175% initial, 1.108% growth and 0.713% termination.

The use of betaine associated or not with choline chloride 70% in Japanese quail diets in the laying phase was evaluated. 504 Japanese quails (Coturnix cortunix Japonica) were used from 104 to 208 days old, in a 3x2 + 1 factorial design, completely randomized design, seven treatments, nine replications, eight birds per experimental unit. Betaine was supplemented in 20% of the digestible methionine level of the control diet, in diets with reformulated betaine the level of enrichment was in the nutritional matrix of the product (100%) and with an extra recovery of 5% (105%). Choline chloride was fixed at 0.07%. Productive performance, egg quality, histometry, and the number of goblet cells from the duodenum and hepatic glycogen were analyzed. The use of betaine promoted greater weight of the eggs to the control, regardless of the mode of use, the use of choline promoted a superior result in the weight of the eggs. In egg quality, only shell percentage was influenced. The use of the reformulated betaine 100% of the matrix promoted greater height of the villi, and a lower villus: crypt ratio to the treatment with the reformulation enriched by 105%. Hepatic glycogen was not influenced. In goblet cells, the reformulation in an extra 105% of the matrix was superior to the matrix in 100%. The hill reduced villus height, improved villus: crypt ratio, and number of goblet cells. In conclusion, the reformulated betaine enriched in an additional 5% of its nutritional matrix replaces the use of choline chloride in the laying of Japanese quail diets.