Supplementation of fetal bovine serum alters histone modification H3R26me2 during preimplantation development of in vitro produced bovine embryos

Abstract In vitro production (IVP) of bovine embryos is not only of great economic importance to the cattle industry, but is also an important model for studying embryo development. The aim of this study was to evaluate the histone modification, H3R26me2 during pre-implantation development of IVP bovine embryos cultured with or without serum supplementation and how these in vitro treatments compared to in vivo embryos at the morula stage. After in vitro maturation and fertilization, bovine embryos were cultured with either 0 or 2.5% fetal bovine serum (FBS). Development was evaluated and embryos were collected and fixed at different stages during development (2-, 4-, 8-, 16-cell, morula and blastocyst). Fixed embryos were then used for immunofluorescence utilizing an antibody for H3R26me2. Images of stained embryos were analyzed as a percentage of total DNA. Embryos cultured with 2.5% FBS developed to blastocysts at a greater rate than 0%FBS groups (34.85±5.43% vs. 23.38±2.93%; P<0.05). Levels of H3R26me2 changed for both groups over development. In the 0%FBS group, the greatest amount of H3R26me2 staining was at the 4-cell (P<0.05), 16-cell (P<0.05) and morula (P<0.05) stages. In the 2.5%FBS group, only 4-cell stage embryos were significantly higher than all other stages (P<0.01). Morula stage in vivo embryos had similar levels as the 0%FBS group, and both were significantly higher than the 2.5%FBS group. These results suggest that the histone modification H3R26me2 is regulated during development of pre-implantation bovine embryos, and that culture conditions greatly alter this regulation

Influence of a probiotic on broiler performance

The objective of the present study was to evaluate the influence of a probiotic product (composition: Lactobacillus acidophillus (3.5 × 10(11) CFU), Streptcoccus faecium (3.5 × 10(11) CFU) and Bifidobacterium bifidum (3.5 × 10(11) CFU)) on broiler performance. A total of 1200 one-day-old broilers were reared until 42 days of age, and distributed in a completely randomized experimental design with 3 treatments (antibiotic, probiotic and control) with 10 replicates of 40 birds each. Weight gain, feed intake, feed conversion ratio and mortality were evaluated. Concerning weight gain, in the periods of 0-7 and 0-14 days of age, the group fed the antibiotic product presented higher values as compared with the other treatments. However, in the periods of 0-21, 0-28 and 0-35 days of age, birds fed the antibiotic presented higher weight gain only in relation to the control group. Feed intake differences were detected only in the initial period of 0-7 days of age, with the group fed the antibiotic product presenting higher feed intake as compared with that fed the probiotic product, although these groups were not different from the control group. No statistical difference was detected in feed conversion ratio among treatments in any of the evaluated age intervals. Mortality was different only in the period of 0-14 days of age, which was higher in the control group as compared with that of the birds fed the probiotic product, but it was not different from the group receiving the antibiotic. Treatment with probiotic product containing Lactobacillus acidophillus, Streptococcus faecium and Bifidobacterium bifidum does not affect broiler performance