Linking key husbandry factors to the intrinsic quality of broiler meat.

Broiler farming is the fastest-growing animal production sector and broiler meat is the second most-consumed meat in the world. The intensification of broiler production often has a negative impact on the meat quality and carcass characteristics. Consumers, however, expect a quality product from animals reared extensively on farms providing good animal welfare, often intuitively associated with extensive farming practices. Therefore, this literature review investigates how the critical factors contributing to the degree of extensiveness of broiler production affect the quality of meat. We used the data from scientific articles published in the years 2012-2021 to analyze the effect of diet (n = 409), genetics (n = 86), enrichment (n = 25), and stocking density (n = 20) on meat quality and carcass characteristics. Minerals and microelements supplementation in the diet improved all the meat quality aspects: sensory, physical, and chemical in most studies. Minerals and enzymes in the diet had beneficial effects on carcass characteristics, unlike feed restriction and ingredient substitutions. The impact of outdoor access on meat quality and carcass characteristics was most frequently examined, in contrast to the use of perches or effects of litter quality. Overall, enrichment did not affect the meat's sensory or physical parameters, but outdoor access improved its lipid composition. Lower stocking density deteriorated intramuscular fat content, decreased tenderness and juiciness, yet lowered cooking and drip loss, and increased carcass and breast muscle yields. When it comes to genetics, in general, slow growing broiler strains have better meat quality parameters, especially regarding yellowness (b*), redness (a*), cooking and drip loss. Our review shows that the factors which contribute to extensiveness of broiler production systems and birds' welfare also affect meat quality and the carcass characteristics.

Using different levels of energy and protein and their effects on bodyweight and blood chemistry of ostriches.

To determine the effect of different dietary energy and protein levels on bodyweight and blood chemistry, 36 ostriches at 2 to 9 weeks of age for feeding conditions and 18 for blood chemistry parameters was used. The birds were divided into six treatment groups. Energy and protein levels of diet were 2400 and 2600 kcal/kg and 20%, 22%, and 24%, respectively. The feed intake and bodyweight gain were determined a weekly. Blood chemical parameters including glucose, HDL, LDL, total cholesterol, triglycerides, total protein, albumin, globulin, aspartate amino-transferase and alanine amino-transferase activity were determined. The highest weight gain during the whole experiment was observed in ostriches offered 2400 kcal · kg-1 dietary energy and 20% protein. The lowest level of total cholesterol and protein was observed in treatment V (2600 kcal · kg-1 dietary energy and 22% protein). The lowest level of glucose and triglycerides was noted after treatment I. The highest albumin and globulin concentrations were in treatment III (2400 kcal · kg-1 dietary energy and 24% protein) and treatment II (2400 kcal · kg-1 dietary energy and 22% protein), respectively. The energy level had no effect (P < 0.05) on feed intake and weight gain in all experimental period. The results of this study showed that with increasing energy and protein levels, most blood parameters increased in ostriches but total cholesterol did not.

Dietary supplementation of Aspergillus oryzae meal and its effect on performance, carcass characteristics, blood variables, and immunity of broiler chickens.

This study investigated the effect of different levels and consumption periods of Aspergillus oryzae meal on performance, carcass characteristics, blood variables, and immunity of broiler chickens. A total of 270 (male and female) Ross 308 chicks were randomly assigned to 9 treatment groups. Two levels (2 g/kg diet and 4 g/kg diet as-fed) of Aspergillus oryzae meal (AO) and 4 consumption periods of AO (starter, grower, finisher, and entire period) in a 2 × 4 factorial arrangement were used. Compared with control, AO used during the entire rearing period increased weight gain, reduced relative weight of abdominal fat, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) serum levels, and increased antibody titers against influenza and Newcastle disease vaccination and sheep red blood cells injection. Few differences in the variables considered were found if AO was added to broiler diets only during specific consumption periods, and between the two supplementation levels of AO. In conclusion, the addition of AO to the broiler diet can have beneficial effects in terms of performance, carcass composition, and health, but these positive effects were mainly reached adding AO for the entire rearing period.