To investigate the effects of boron on growth performance and meat quality, 10-day-old Africa ostrich chicks were randomly divided into 6 groups with 6 replicates in each group. For 80 days, birds in the treatments were fed the same basal diet but given different concentrations of boron-supplemented water. The highest final BW (33.4 ± 0.30 kg), ADFI (376 ± 1.83 g), and ADG (224 ± 1.01 g) appeared in the group receiving 160 mg/L boron (group 4). 160 mg/L boron also decreased drip loss (2.20 ± 0.59), cooking loss (35.3 ± 1.14), and elevated pH value (6.13 ± 0.28) of meat (P < 0.05). Ostrich chicks in the 640 mg/L treatment group (group 6) had the lowest final BW (30.8 ± 1.05 kg) and ADG (208 ± 0.74 g) (P < 0.05). The highest ash (1.35 ± 0.01%) and pH (6.18 ± 0.03) and the lowest protein (20.4 ± 1.74%), drip loss (2.10 ± 0.76%), cooking loss (35.0 ± 0.41%), C18:1 (28.2 ± 0.65%), and C18:3ω3 (2.60 ± 0.51%) appeared in group 6 (P < 0.05) as well. Overall, the optimum concentration of 160 mg/L supplemental boron improved ostrich growth performance and meat quality; however, high concentrations of boron decreased both performance and meat quality.

•OsBAFF gene encodes a 288-amino acid.•The OsBAFF gene is strongly expressed in the bursa of fabricius, thymus, spleen, and bone marrow.•His-OsBAFF was efficiently expressed in E. coli Rosset (DE3).•Purified OsBAFF can promote the survival of African ostrich bursal lymphocytes and co-stimulate proliferation of mouse splenic B cells.B cell activating factor (BAFF), which belongs to the tumor necrosis factor (TNF) family, is testified to play a critical role in B cell survival, proliferation, maturation and immunoglobulin secretion. In the present study, the cDNA of open reading frame (ORF) in African ostrich (Struthio camelus) BAFF (designated OsBAFF) was cloned by reverse transcription-PCR (RT-PCR). The OsBAFF gene encodes a 288-amino acid protein containing a predicted transmembrane domain and a putative furin protease cleavage site like BAFFs from chicken (cBAFF), quail (qBAFF), duck (dBAFF), goose (gBAFF) and dove (doBAFF). RT-PCR analysis showed that the OsBAFF gene is strongly expressed in the bursa of Fabricius, thymus, spleen, and bone marrow. The soluble OsBAFF had been cloned into pET28a. SDS-PAGE and Western blotting analysis confirmed that the soluble fusion protein His-OsBAFF was efficiently expressed in Escherichia coli Rosset (DE3). In vitro, purified OsBAFF was not only able to promote the survival of African ostrich bursal lymphocytes, but also able to co-stimulate proliferation of mouse splenic B cells. The expression of OsBAFF in lymphocyte cells was higher than the control after LPS stimulation. These findings indicated that OsBAFF plays an important role in survival and proliferation of African ostrich bursal lymphocytes, which may provide valuable information for research into the immune system of African ostrich and OsBAFF may serve as a potential immunologic factor for enhancing immunological efficacy in African ostrich and any other birds.

The thymus in addition to being a central lymphoid organ is also an endocrine organ which produces various neuropeptides that influence the function of this gland. Somatostatin is a neuropeptide that was isolated initially in the hypothalamus and which inhibits the release of growth hormone. The distribution of somatostatin-producing cells and the sequence of somatostatin have been determined in many species. In the present study, we investigated the expression of somatostatin in the thymus of the African ostrich and its sequence by reverse-transcriptase polymerase chain reaction and immunohistochemistry. The results showed that somatostatin mRNA was expressed in the thymus and somatostatin immunoreative cells were distributed in both the cortical and medullary regions of the thymus. Results of cDNA cloning revealed that the nucleotide sequence and the encoded protein of African ostrich somatostatin were 348 bases and 116 amino acids in length and that it is highly conserved to that of other reported species. These findings indicated that the somatostatin expressed in the thymus of ostrich might play an important role in the function of the gland. In addition, this research has provided novel molecular data allowing further study of somatostatin in the ostrich.