Coronavirus infections have been a part of the animal kingdom for millennia. The difference emerging in the twenty-first century is that a greater number of novel coronaviruses are being discovered primarily due to more advanced technology and that a greater number can be transmitted to humans, either directly or via an intermediate host. This has a range of effects from annual infections that are mild to full-blown pandemics. This review compares the zoonotic potential and relationship between MERS, SARS-CoV, and SARS-CoV-2. The role of bats as possible host species and possible intermediate hosts including pangolins, civets, mink, birds, and other mammals are discussed with reference to mutations of the viral genome affecting zoonosis. Ecological, social, cultural, and environmental factors that may play a role in zoonotic transmission are considered with reference to SARS-CoV, MERS, and SARS-CoV-2 and possible future zoonotic events.

Background: There is increasing research interest in using short-chain fatty acids (SCFAs) including butyrate as potential alternatives to antibiotic growth promoters in animal production. This study was conducted to evaluate the effects of supplementation of sodium butyrate (SB) in milk and/or milk replacer on the growth performance, rumen fermentation, and serum antioxidant capacity and immunoglobins in dairy calves before weaning. Forty healthy female Holstein calves (4-day-old; 40 ± 5 kg of body weight) were housed in individual hutches and randomly allocated to 1 of 4 treatment groups (n = 10 per group). The control group was fed no SB (SB0), while the other three groups were supplemented with 15 (SB15), 30 (SB30), or 45 (SB45) g per day of SB mixed into milk and/or milk replacer. Results: The SB supplementation enhanced growth and improved feed conversion into body weight gain compared with the SB0 group. No significant effect on rumen pH; concentrations of NH3-N, individual and total VFAs; or acetate: propionate (A:P) ratio was found during the whole experimental period. The serum glutathione peroxidase activity was higher in the SB30 and SB45 groups compared with the SB0 group, and the serum level of maleic dialdehyde linearly decreased as the SB supplementation amount increased during the whole experiment. Not influence of SB supplementation was observed on serum concentrations of immunoglobulin A, immunoglobulin G, or immunoglobulin M during the whole experimental period. Conclusions: Under the conditions of this study, SB supplementation improved growth performance and antioxidant ability in pre-weaned dairy calves. We recommended 45 g per day as the optimal level of SB supplementation (mixed into milk and/or milk replacer) to improve the growth and antioxidant function of dairy calves before weaning.

This study was designed to determine the effect of phytase extracted from Aspergillus niger (Natuphos ® E) on growth performance, bone mineralization, phosphorous excretion, and meat quality parameters in broilers fed available phosphorous (aP)-deficient diet. In total, 810 one-day-old Indian River broilers were randomly allotted into one of three dietary treatments, with six replicates per treatment. The three dietary treatments were 1) control group (CON: basal diet with sufficient aP), 2) low phytase (LPY: available phosphorus-deficient diet supplemented with 0.01% phytase), and 3) high phytase (HPY: available phosphorus-deficient diet supplemented with 0.02% phytase). Average daily gain and, feed intake, and feed conversion ratio were measured for 35 days. Excreta were collected from each pen on day 35. One broiler from each cage was euthanized to collect visceral organs and tibia samples. Broiler chickens fed LPY and HPY showed improved (P＜0.05) growth performance compared to broilers fed CON on day 35. The tibia length of HPY-fed broilers was more than those of broilers fed other diets on day 35 (P＜0.05). However, tibia calcium and phosphorous contents in LPY-fed broilers was higher (P＜0.05) than in CON and HPYfed broilers. Tibia length and calcium and phosphorous content showed a positive correlation (P＜0.05) with the weight gain of broilers on day 35. Phosphorous level in the excreta of LPY-and HPY-fed broilers was lesser than those of CON broilers on day 35 (P＜0.05). Furthermore, HPY-fed broilers showed lower (P＜0.05) phosphorous content in the excreta than LPY-fed broilers. LPY-and HPY-fed broilers showed higher (P＜0.05) liver weight than the CON broilers. In conclusion, broilers fed aP-deficient diet supplemented with phytase from Aspergillus excreted less phosphorus, which enhanced growth performance and tibia development from time of hatching to day 35 posthatching.

Docosahexaenoic acid (DHA) can improve human and animal health, particularly including anti-inflammatory, antioxidant, anticancer, neurological, and visual functions. Schizochytrium sp. is a marine heterotrophic protist producing oil with high DHA content, which is widely used in animal and food production. However, different fermentation conditions have intensive impacts on the growth and DHA content of Schizochytrium sp. Thus, this study aimed to enhance the DHA yield and concentration of Schizochytrium sp. I-F-9 by optimizing the fermentation medium. First, a single-factor design was conducted to select a target carbon and nitrogen source from several generic sources (glucose, sucrose, glycerol, maltose, corn syrup, yeast extract, urea, peptone, and ammonium sulfate). The Plackett–Burman design and the central composite design (CCD) were utilized to optimize the fermentation mediums. Schizochytrium sp. in 50-mL fermentation broth was cultured in a 250 mL shake flask at 28 °C and 200 rpm for 120 h before collecting the cell pellet. Subsequently, the cell walls were destroyed with hydrochloric acid to extract the fatty acid using n-hexane. The DHA content was detected by gas chromatography. The single-factor test indicated that glucose and peptone, respectively, significantly improved the DHA content of Schizochytrium sp. compared to the other carbon and nitrogen sources. Glucose, sodium glutamate, and sea crystal were the key factors affecting DHA production in the Plackett–Burman test (P = 0.0247). The CCD result showed that DHA production was elevated by 34.73% compared with the initial yield (from 6.18 ± 0.063 to 8.33 ± 0.052 g/L). Therefore, the results of this study demonstrated an efficient strategy to increase the yield and content of DHA of Schizochytrium sp.