In this study, spatial concordance among microcrustaceans, rotifers and testate amoebae was examined in a small pond in Central Brazil. The main goal was to test how consistently different taxonomic groups ordinate 9 sites distributed along the pond's main axis. Microcrustaceans were more abundant during the dry season, characterized by waters with high transparency and dissolved oxygen concentration. An increase in species richness and densities of rotifers and testate amoebae was detected during rainy season, with low values of Secchi disk and concentrations of dissolved oxygen. However, the ordination patterns generated by these groups were different. Concordant patterns across sites were found only between cladocerans and copepods. These results suggest that great care should be taken when ordination patterns based on some taxonomic groups are extrapolated to other groups for detecting environmental changes.

The present study aimed to ascertain the effects of slow-growing breeder age on embryo development, incubation results, and chick quality and of the interaction between breeder age and hatching time on initial performance. A total of 630 hatching eggs obtained from a commercial flock of slow-growing broiler breeders (Isa Label Naked Neck) were evaluated in 2 experiments. The first experiment evaluated embryo development and hatching results for broiler breeder age treatments of 38 and 51 wk, whereas the second experiment evaluated broiler chick performance. For the second experiment, chicks were distributed in a 2 x 2 factorial randomized block (sex) experimental design consisting of 2 breeder ages (31 or 58 wk) and 2 hatching times (479–485 and 491–497 h). At 18 d of embryonic development, embryos of 51-wk-old breeders were larger than those of 38-wk-old breeders ( P < 0.05), whereas yolk-free chick weight was similar ( P > 0.05). Embryo organ weight was similar for the 2 breeder ages ( P > 0.05); however, there was greater development of intestinal villi for embryos of the 51-wk-old breeders. There were no differences between breeder ages in hatchability and chick quality score ( P > 0.05). Yolk-free chick weight at pulling was greater ( P < 0.05) for chicks from 51-wk-old breeders. Hatching time did not affect performance from 1 to 7 d ( P > 0.05); however, chicks hatching at 491–497 h had better performance from 1 to 28 d than did chicks hatching at 479–485 h ( P < 0.05). In conclusion, the age of slow-growing breeders affects embryo villi development and chick weight but does not improve incubation results or chick quality. Chicks hatching later (491–497 h) had better performance results than chicks hatching earlier (479–485 h).

Reproduction Full-length research article Macroscopic embryonic development of Guinea fowl compared to other domestic bird species ABSTRACT-Since few studies have addressed the embryonic development of Guinea fowl (Numida meleagris), the objective of the present study was to evaluate its embryonic development in the Cerrado region of Brazil and compare the results to published descriptions of the embryonic development of other domestic bird species. The commercialized weight for Guinea fowl eggs used in the experiment was found to be 37.57 g, while egg fertility was 92%. Embryo growth rate (%) was higher on the sixth day of incubation relative to other days. The heart began beating on the third day of development, while eye pigmentation and upper and lower limb buds appeared on the sixth day. The yolk sac was incorporated on the 24th day followed by chick external pipping and hatching on the 28th day. Comparisons revealed that the embryonic development of Guinea fowl exhibits both similarities to, and differences from, the embryonic development of other domestic birds. From three days of embryonic development, differences were observed among the compared species. Despite the same incubation period, Guinea fowl embryos develop faster than turkeys. All species begin internal pecking two days before hatching and internal pecking 24 h before hatching.