Performance, physical egg quality, and economic index of laying hens under different rearing systems / Desempenho, qualidade do ovo e índice econômico de poedeiras em diferentes sistemas de criação

The objective was to evaluate the performance, physical egg quality (weight and gravity), and economic index of laying hens reared in cage and cage-free systems. A total of 312 40-week-old Hy-line brown laying hens were distributed in a fully randomized design, split into two treatments (cage-free and cage) with 12 replicates in each system. We housed 144 birds in galvanized-wire cages (12 birds each) and 168 birds in a cage-free system in boxes with wood shaving bedding (14 birds each). The experiment lasted 112 days and divided into four 28-day periods. Regarding performance, feed intake (g) and feed conversion (g/g) of birds reared in the cage-free system were higher (p<0.0001) than the cage system, but no differences were observed (p>0.05) for the other performance parameters and also for egg quality. As for economic index, egg production in the cage-free system was higher (p<0.0001) than the cage system. In conclusion, birds reared in the cage-free system have higher feed consumption but worse feed conversion, increasing egg production cost compared to caged birds; however, there are no changes in egg production and physical quality.(AU)

Objetivou-se avaliar o desempenho, qualidade de ovos e índice econômico de poedeiras semipesadas criadas em sistemas cage-free e em gaiolas. Foram utilizadas 312 poedeiras da linhagem Hy Line Brown, com 40 semanas de idade, distribuídas em um delineamento inteiramente casualisado (DIC), em dois tratamentos (cage-free e gaiolas) com 12 repetições em cada sistema, sendo 144 aves alojadas em gaiolas de arame galvanizado com 12 aves em cada gaiola e 168 aves alojadas em sistema cage-free, em boxes sobre cama de maravalha com 14 aves em cada repetição. O experimento teve duração de 112 dias, divididos em quatro períodos de 28 dias. Nos parâmetros de desempenho, o consumo de ração (g/aves/dia) e a conversão alimentar (g/g) foi maior (P<0,0001) nas aves criadas no sistema cage-free comparado ao sistema de gaiolas, não sendo observado diferença (P>0,05) nos demais parâmetros de desempenho e também na qualidade de ovos. No índice econômico, a produção de ovos em sistema cage-free apresentou maior valor (P<0,0001) em relação ao sistema de gaiola. Conclui-se que as aves criadas em sistema cage-free apresentam maior consumo de ração, pior conversão alimentar ocasionando um maior custo nos ovos em relação às aves criadas em gaiolas, no entanto não há alteração na produção e qualidade dos ovos.(AU)

Phenolic content and ferric reducing-antioxidant power of cow's milk produced in different pasture-based production systems in southern Brazil.

BACKGROUND: Phenolic compounds are widely present in forage. However, few studies have been carried out to investigate the presence of these compounds in animal products such as milk. In this study, the total phenolic content (TPC) and ferric reducing-antioxidant power (FRAP) of milk produced under agroecological and conventional management systems in southern Brazil were determined. Three systems were compared: (a) agroecological, with intensive rotational grazing, also known as Voisin grazing (ECO); (b) semi-intensive conventional (SIC); and (c) conventional grazing (CGR) (n = 8 per group). Pastures with distinct and more diverse botanical composition were observed on the ECO farms. RESULTS: Significantly (P < 0.05) lower amounts of TPC were found in agroecologically produced milk in autumn and summer and the CGR system showed the highest FRAP value (P < 0.05) for the samples collected in autumn. Positive correlations where found between the TPC and FRAP values obtained for the milk samples (0.198, P < 0.05), milk FRAP and forage TPC values (0.344, P < 0.05), and the TPC and FRAP values obtained for the forage (0.70, p < 0.01). PCA applied to the UV spectra dataset (200-350 nm) clearly distinguished the samples collected from the ECO system in the winter. CONCLUSION: Our results revealed that, under the conditions prevalent in southern Brazil, since the cows were allowed to graze in all of the systems, the TPC and antioxidant capacity of the milk samples showed minimal variation. However, since the forage TPC and FRAP values for the milk were correlated, TPC appears to be a promising variable for the purpose of monitoring forage prior to its selection aimed at enhancing the antioxidant activity of milk.