Productive performance, eggshell quality, and eggshell ultrastructure of laying hens fed diets supplemented with organic trace minerals.

This study was carried out with the purpose of evaluating the effect of supplementing hens' diets with trace minerals from inorganic or organic sources on the productive performance, eggshell quality, and eggshell ultrastructure of laying hens. Three hundred sixty Hy-Line W36 laying hens between 47 to 62 wk of age were used and distributed in a completely randomized experimental design with 9 treatments, 5 replicates, and 8 birds for each experimental unit. The treatments consisted of a control diet without supplementation of the trace minerals Mn, Zn, and Cu; 4 supplementation levels of these trace minerals from an inorganic source; and the same levels of supplementation from an organic source (proteinates). The supplementation levels in milligrams per kilogram for Mn, Zn, and Cu, were, respectively, 35-30-05, 65-60-10, 95-90-15, and 125-120-20. There was no effect of supplementation of trace minerals on the rate of posture, feed intake, feed conversion, specific weight, and Haugh unit of eggs. However, there was a quadratic effect (P < 0.05) of the levels of trace mineral supplementation on average egg weight and egg mass; the results did not differ regarding the source used. The increase in the levels of supplementation of Mn, Zn, and Cu provided a linear increase (P < 0.05) in the breaking strength and the percentage of eggshell. There was a linear decrease (P < 0.05) in the egg loss and the number of mammillary buttons in the shell. The best results were obtained using diets supplemented with trace minerals from an organic source because these diets provided lower egg loss, higher thickness, and increased strength of the shell. Structurally, organic Mn, Zn, and Cu provided higher thickness of the palisade layer and lower mammillary density. The trace mineral supplementation improved the structural characteristics and the quality of the eggshells.

Oocyte aspiration and in vitro embryo production in Jersey cows with selenium-supplemented diet / Aspiração de oócitos e produção de embriões in vitro de vacas Jersey suplementadas com selênio na dieta

The effects of selenium (Se) in Jersey cows' diet on the aspiration of oocytes and production of embryos in vitro were studied. Groups with five Jersey cows received 3.2mg or 9.6mg Se daily, provided in the feed concentrate. Six follicular aspirations were carried out every 15 days, using only the last 5. The oocytes were classified, and standard procedures were carried out for maturation, fertilization and cultivation. The total number of oocytes (35.11±2.65 vs 23.10±2.16) and degree 1 oocytes (11.61±2.65 vs 4.75±0.97) were higher in the group that received 9.6mg Se and the quantity of naked oocytes (3.23±0.87 vs 6.22±1.18) was lower in this group. The aspirated oocytes from the cows treated with 9.6mg Se/day resulted in higher (P<0.05) embryo production 21.98±2.37 vs 13.12±1.59). No difference was observed in serum Se concentration between the two groups. It is recommended that the daily diet be supplemented with 100g mineral salt containing 9.6mg Se, since this rate rendered a larger production of oocytes, higher quantity of degree 1 oocytes and greater production of embryos in the process of in vitro fertilization.

Avaliou-se o efeito do selênio (Se) adicional na dieta de vacas Jersey na aspiração de oócitos e produção de embriões in vitro. Dez vacas Jerseys receberam 3,2mg de Se por dia ou 9,6mg, vinculado ao concentrado. Realizaram-se seis aspirações foliculares, com intervalo médio de 15 dias, aproveitando as cinco últimas. Os oócitos foram classificados e realizaram-se os procedimentos padrões de maturação, fertilização e cultivo in vitro. O total de oócitos, 35,11±2,65 vs 23,10±2,16, e oócitos de qualidade 1, 11,61±1,58 vs 4,75±0,97, foram mais elevados no grupo que recebeu 9,6mg de Se e a quantidade de oócitos desnudos mais baixa, 3,21±0,87 vs 6,22±1,18. A produção de embriões foi maior no grupo tratado com 9,6mg de Se/vaca/dia, 21,98±2,37 vs 13,12±1,59. Não se observou diferença na concentração de Se no soro entre os dois grupos. Conclui-se que é possível recomendar o fornecimento de 100g de sal mineral, contendo 9,6mg de Se, adicionado à dieta, pois resultou em maior produção de oócitos, maior quantidade de oócitos de grau 1 e maior produção de embriões no processo de fecundação in vitro.