This study aimed to investigate the effects of various Zn sources on the performance, health, antioxidant activity, and immune response in early lactation dairy cows. Thirty Holstein cows with similar physiological conditions were randomly assigned to one of three treatment groups, each receiving a distinct supplement: Zn sulfate (CON), Zn amino acid complex (Zn-AA), or Zn methionine complex (Zn-Met), at a dosage of 60 mg/kg on a dry matter basis. The experiment lasted for 67 days, including a 7-day pre-feeding period. The results indicated that supplementation with Zn-AA and Zn-Met significantly reduced the milk somatic cell count compared to the control group (p = 0.001). Interestingly, glutathione peroxidase (GSH-PX) levels were markedly increased in both the Zn-AA and Zn-Met groups relative to the control group (p = 0.003), with Zn-AA also demonstrating a significant increase in catalase (CAT) content (p = 0.001). Both Zn-AA and Zn-Met led to significant elevations in IgA and IgM content (p < 0.05). Furthermore, milk Zn content in the Zn-Met groups was significantly elevated than that compared with the control group (p < 0.001). In conclusion, organic Zn supplementation resulted in a reduction in the somatic cell count, alongside notable increases the immunoglobulins, milk Zn content, and GSH-PX levels. This study suggests that organic Zn sources, particularly the Zn-AA, are more effective for enhancing the health of dairy cows.

This study aims to provide a theoretical basis on the regulatory mechanism of the α-l,2-fucosyltransferase (FUT1) gene in pigs by analyzing the transcriptional activity of its promoter region. On the basis of the previously obtained promoter sequence, primers upstream and downstream of the gene were designed using the restriction endonucleases KpnI and HindIII respectively, and the recombinant plasmids of the pGL3-promoter were constructed by inserting promoter sequences with partially missing regions. The resultant mutants were observed by transient transfection assay into HEK293 cells, and the transcriptional activity of the promoter region was determined by luciferase activity. The 5'-flanking region of the FUT1 gene (−1150 to +50 bp) exhibited promoter activity. The −1150-bp to −849-bp region showed negative regulation of the gene. The recombinant plasmid pGL3-898 showed the strongest luciferase activity, and the activity showed a decreasing trend when the deleted region was increased. Recombinant plasmids were successfully constructed, verified, and the positive and negative regulation areas and core promoter region were detected, providing a deeper insight into the transcriptional regulatory mechanism of the FUT1 gene.

Saccharomyces cerevisiae fermentation products (SCFP) can potentially promote gastrointestinal growth and immunity in young livestock. However, reports within the existing literature on the effects of SCFP supplements on calves have been inconsistent; therefore, we perform the following experiments to resolve the inconsistencies. A total of 22 Holstein calves [10 d after birth, BW = 48.93 ± 3.99 kg (mean ± SD)] were assigned randomly into two groups, namely the control group (CON) and SCFP group, each having 11 replicas. The calves in the CON were fed a basal diet, while the SCFP group was fed the basal diet supplemented with 5g/head/d SCFP (NutriTek, Diamond V, Cedar Rapids, IA52404, United States) incorporated into feed. All the calves were regularly fed thrice daily at 08:00, 14:30, and 21:00 and had free access to water. A 5-day adaptation phase was followed by a 45-day experimental period. The results showed that compared to the CON, at the end of the d-45 trial, the body weight was significantly greater in the SCFP group (p < 0.05), and during the 1-45 days, the ADG was higher (p < 0.05). The FCR in the 30-45 days SCFP group was higher (p < 0.05). Furthermore, the apparent digestibility of DM, CP, EE, ADF, Ca, and P were significantly increased in the SCFP group, except for NDF (p < 0.05). The concentration of GH and IGF-1 in serum showed a tremendous increase (p < 0.05) with SCFP supplementation on d 15 and d 45. On d 15, SCFP supplementation significantly increased the serum IgA contents (p < 0.05). Notably, on d 15 and d 45, the serum concentrations of IL-1β, IL-6, and TNF-α reduced (p < 0.001). Moreover, the Actinobacteriota in the SCFP group were significantly lower than those in the CON group (p = 0.034). SCFP significantly increased the abundance of Butyricimonas, Parabacteroides, and Ruminococcus. The differences among sob, Chao1, and PD-tree groups were statistically significant (p < 0.05). In conclusion, these results demonstrate that SCFP supplementation improved ADG, apparent digestibility and serum hormone, enhanced immunity, and regulated gut microbiota, thereby jointly promoting the growth of pre-weaning calves.