With the continued increases in broilers production, the negative impact of environmental conditions on birds has attracted increasing public awareness and concern. Heat stress is one of the most important environmental stressors challenging broiler production world-wide. The detrimental effects of heat stress on broilers range from reduced growth to decreased quality of broiler products. This review focuses on the available scientific evidence for the impact of heat stress in broiler production, with emphasis on performance, physiological and biochemical effects, muscle oxidation, and meat quality.

Broiler production in certain countries often suffers from an inadequate supply of local high-quality protein. Increased production of sunflower seeds (Helianthus annuus L.) for oil can provide more meal that can provide protein and offset the need for soybean meal, which is often unavailable due to cost. Presently, due to adaptive capabilities in various climatic and soil conditions, sunflower seeds are grown worldwide. Sunflower seed meal (SFSM), a by-product from oil production for human consumption, varies in quality due to variations in oil extraction methods, seed varieties and processing techniques. However, investigators reported that SFSM can replace up to two thirds of the soybean meal protein in the starter and finisher diets of broilers. This review includes the quality of SFSM as related to the effect of processing and as a feed ingredient in broilers diets.

Cholesterol has been used to monitor artifact generation. Stability differences among cholesterol oxide products (COPs) and cholesterol in thermal and alkaline conditions are theorized. Thus, use of cholesterol may be unsuitable for detection of artifacts generated from COPs. Stability of cholesterol was compared to that of 7‐ketocholesterol (7‐keto) and β‐sitosterol (βS) under various thermal and alkaline saponification conditions: 1 M methanolic KOH for 18 h at 24 °C (1 M18hr24°C, Control), 18 h at 37 °C (1M18hr37°C), 3 h at 45 °C (1M3hr45°C), and 3.6 M methanolic KOH for 3 h at 24 °C (3.6M3hr24°C). Trends indicated that cholesterol in solution was more stable than 7‐keto under all conditions. Compared to βS, cholesterol was more stable under all conditions except for 1M18hr37°C for which stabilities were similar. Compounds were more labile in heat than alkalinity. Poor recoveries of 7‐keto during cold saponification with high alkalinity were attributed to alkaline instability. 7‐Keto, less stable than cholesterol, should be used to monitor artifact generation during screening of various methods that include thermal and alkaline conditions. In a preliminary analysis of turkey meat, more 3,5‐7‐one was generated from spiking with cholesterol than with 7‐keto.

The northern fowl mite (NFM), Ornithonyssus sylviarum, is the most common ectoparasite of laying hens in North America. Infestation can cause a reduction in egg production, egg weights, and feed conversion efficiency. However, there is a lack of information on the effects of NFM on hen physiology, physical condition, and egg quality. Singly caged beak-trimmed White Leghorn hens (N = 32) were infested with mites at 25 wk of age. The condition of each hen was assessed at wk 0 (infestation) and wk 5 and 7 post-infestation to determine comb temperatures and feather, skin, and comb condition. Heterophil-lymphocyte (H/L) ratios and body weight (BW) were evaluated at wk 0 and wk 1, 3, 5, and 7 post-infestation. Egg weight, egg specific gravity, yolk color, Haugh unit (HU), and eggshell thickness were determined prior to infestation (wk −1) and at 1, 3, 5, and 7 wk post-infestation. The H/L ratio (P < 0.0001), HU (P < 0.0001), and egg specific gravity (P = 0.001) were lowest, and the egg yolk color was lightest (P = 0.087) at wk 5, the peak of infestation. At wk 5 and 7, more than 65% of the hens had red skin and more than 75% had scabs on the vent; in addition more than 84% had grey-black vent feathers. There were no effects of infestation on comb color, comb temperature, feather cover, BW, or eggshell thickness. It was concluded that infestation with NFM has negative effects on interior egg quality and hen integument. A decrease in H/L ratio was also observed at the peak of infestation. However, the effects of NFM on the immune system are unclear, and H/L ratio might not be a good stress measure in hens highly infested with NFM.

If freshly dried tomato pomace could be fed to poultry, its naturally occurring α-tocopherol would retard lipid oxidation during further processing,