ABSTRACT
Chlorella vulgaris (CV) is a microalga with considerable nutritional value, containing high levels of protein, carotenoids, and polyunsaturated fatty acids, which have the potential to positively influence the productive performance and egg quality of laying hens. CV emerges as a more sustainable ingredient than soybean meal (SBM) as it can be produced locally and with fewer inputs. In this regard, a study was conducted with 48 H&N Brown Nick strain laying hens, at 19 weeks of age, over a period of 16 weeks. The hens were divided into four treatments, with 12 replicates each. The treatments consisted of providing four different diets: a control diet based on corn and SBM without the inclusion of CV, and three other diets with partial substitution of SBM by 2.5, 5, and 10% of CV. The results showed that the inclusion of CV in the diets did not significantly affect feed intake, feed conversion ratio, or egg production (p > 0.05). In addition, moderate CV levels increased egg weight, while higher levels reduced it. Haugh units, yolk index, albumen index, egg surface area, specific density, and translucency were not affected (p > 0.05), while shell index and shell thickness were lower in the groups that received the CV (p < 0.0001). Yolk color improved significantly with increasing CV levels (p < 0.0001), with darker, more intensely colored yolks at higher CV concentrations. The results of this study suggest that the incorporation of CV in the diet of laying hens had a limited impact on performance parameters. In addition, CV supplementation can positively influence egg quality and yolk color, although careful consideration of optimal levels is necessary to avoid negative effects on other parameters.
ABSTRACT
The diet offered to animals has a great influence on the composition of tissues and, consequently, the quality. The objective of this study was to evaluate the influence of Amazonian ecosystems, in the dry and rainy periods of the year, on the composition of cholesterol, tocopherols, ß-carotene and the fatty acid profile of the livers of water buffaloes (Bubalus bubalis) reared in the Eastern Amazon, in an extensive or intensive system. Total lipid content was influenced by the location and time of year (p < 0.05). Ninety-six male water buffaloes were used (12 per sampling period), aged between 24 and 36 months, with average weights of 432 kg (end of the rainy season) and 409 kg (end of the dry season). Total cholesterol, α-tocopherol and γ-tocopherol influenced the relationship between extensive vs intensive ecosystems, location, periods and the interaction between the location and period of the year (p < 0.05). Animals raised in a pasture ecosystem had the highest values of omega-3, and those raised in confinement, the highest values of omega-6 (p < 0.05). The proportions of n-6/n-3 and hypocholesterolemia (7.14) and hypercholesterolemia (3.08%) (h/H) were found in greater amounts in animals raised in confinement (p < 0.05). The atherogenic index (AI) had a higher value in the rainy season, in animals raised in Santarém (2.37%), with no difference between pasture and feedlot ecosystems, except in animals raised in the rainy season in Nova Timboteua, with a lower AI (1.53%). The thrombogenicity index (TI) was higher in the livers of confined animals (0.32%) and lower (0.18%) in those raised in Nova Timboteua (rainy season). Amazonian ecosystems influence the nutritional values of buffalo liver, with the best nutritional values in animals in the extensive system.
ABSTRACT
The aim of this study was to analyze the influence of distinct production systems and seasonal variation in the Brazilian Eastern Amazon on the meat lipid composition of water buffaloes. Water buffaloes were reared in commercial farms in the Eastern Amazon either in extensive systems (Marajó Island, Nova Timboteua and Santarém locations), during rainy or dry seasons, or intensive (feedlot) systems. Animals reared in extensive systems were fed natural pastures, and those reared in feedlots were fed sorghum silage and commercial pellets. Buffaloes were slaughtered and ribeye muscle (longissimus lumborum) samples collected. Lipid-soluble antioxidant vitamins and fatty acids were analyzed. The nutritional value of meat from buffaloes reared in Marajó Island extensive system during the rainy season was higher than that of other systems, as it had lower levels of cholesterol and higher amounts of α-tocopherol associated with higher hypocholesterolaemic/hypercholesterolaemic ratio and lower index of atherogenic. Also, this meat had lower percentages of saturated fatty acids and higher proportions of mono- and polyunsaturated fatty acids (PUFA), particularly n-3 PUFA, with increased PUFA/saturated fatty acids ratio and decreased n-6/n-3 PUFA ratio. However, all extensive systems produced meat with a relatively low index of thrombogenicity values, which is advantageous for human health.