Reclamation of Astragalus By-Product through Dietary Inclusion in Ruminant Diets: Effects on Growth Performance, Nutrient Digestibility, Rumen Fermentation, Blood Biochemical Parameters, and Humoral Immune Response in Sheep

Effect of Zanthoxylum bungeanum essential oil on rumen enzyme activity, microbiome, and metabolites in lambs

Antibiotics were once used in animal production to improve productivity and resistance to pathogenic microbiota. However, due to its negative effects, the search for a new class of substances that can replace its efficacy has become one of the urgent problems to be solved. Plant essential oils (EOs) as a natural feed additive can maintain microbiota homeostasis and improve animal performance. However, its specific mechanism of action needs to be further investigated. Therefore, we added different doses of essential oil of Zanthoxylum bungeanum (EOZB) to the diets of Small Tail Han Sheep hybrid male lambs (STH lambs) to evaluate the effect of EOZB on rumen enzyme activity, rumen microbiology, and its metabolites in STH lambs. Twenty STH lambs were randomly divided into four groups (n = 5/group) and provided with the same diet. The dietary treatments were as follows: basal diet (BD) group; BD+EOZB 5 ml/kg group; BD+EOZB 10 ml/kg group; BD+EOZB 15 ml/kg group. We found that EOZB 10 ml/kg helped to increase rumen pectinase (P<0.05) and lipase (P<0.05) activities. Microbial 16S rRNA gene analysis showed that EOZB significantly altered the abundance of rumen microbiota (P<0.05). LC/GC-MS metabolomic analysis showed that the addition of EOZB produced a total of 1073 differential metabolites, with 58 differential metabolites remaining after raising the screening criteria. These differential metabolites were mainly enriched in glycerophospholipid metabolism, choline metabolism in cancer, retrograde endocannabinoid signaling, benzoxazinoid biosynthesis, and protein digestion and absorption. Correlation analysis showed that some rumen microbiota were significantly correlated with differential metabolite and enzyme activities.

Novel Crabtree negative yeast from rumen fluids can improve rumen fermentation and milk quality

Upgrading the nutritive value of rice straw (RS) is necessary to increase its contribution to enhancing meat and milk production. Present work verified whether novel Crabtree negative yeast inoculant could promote RS utilization, rumen fermentation, and milk quality in tropical crossbred lactating Holstein cows. The new stain of Crabtree negative yeasts (Pichia kudriavzevii KKU20 and Candida tropicalis KKU20) was isolated from the rumen of dairy cattle. This study used 6 multiparous crossbreds between Holstein Frisian × Zebu dairy cows in their mid-lactation period. Dairy cows were randomly allocated to three ensiled RS with various yeast stains including Saccharomyces cerevisiae, P. kudriavzevii KKU20, and C. tropicalis KKU20 according to a 3 × 3 replicated Latin square design. Crabtree-negative yeast (P. kudriavzevii and C. tropicalis) increased the apparent digestibility of dry matter by about 6.9% when compared with Crabtree-positive yeast (S. cerevisiae). Bacterial populations were highest with ensiled RS by C. tropicalis KKU20. Ensiled RS with Crabtree-negative yeasts were significantly increased with total volatile fatty acids, but they did not affect volatile fatty acid profiles. Milk protein precentage was highest at 35.6 g/kg when C. tropicalis was fed, and lowest when applied with S. cerevisiae and P. kudriavzevii KKU20 in ensiled RS at 34.5 and 34.1 g/kg, respectively. Thus, feeding ensiled RS with novel Crabtree negative yeast could improve RS digestion, rumen fermentation, and milk protein content in dairy cows.

Traditional Chinese herbal medicine complex supplementation improves reproductive performance, serum biochemical parameters, and anti-oxidative capacity in periparturient dairy cows

This study was conducted to investigate the effects of a traditional Chinese herbal medicine complex (TCHMC) on the productive performance of periparturient dairy cows. Eighteen non-lactating pregnant Holstein dairy cows with similar body conditions with 1 to 2 parity were randomly divided into three groups (n = 6), receiving a basal diet with 0 (CON group), 200 (T-200 group), and 300 (T-300 group) g TCHMC per day from 14 to 9 days prepartum. The results demonstrated that TCHMC treatments decreased the days of gestation, calving to first service, and calving to first visible estrus. Compared with CON at specific time points, TCHMC treatments increased the concentrations of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E₂), whereas progesterone (P₄) and E₂ concentrations decreased. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and creatine kinase (CK) concentrations were downregulated, whereas that of globulin (GLB) and immunoglobulin G (IgG) were upregulated by TCHMC treatments around the time of calving. Compared with CON and T-200 treatments, the T-300 treatment increased the serum concentrations of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT) and total antioxidant capacity (T-AOC) and decreased the malondialdehyde (MDA) concentration from 7 d prepartum to 21 d postpartum when. In addition, although TCHMC treatment had no effect on average birth weight, heart rate, respiratory rate, and body temperature of calves, the T-300 treatment increased serum albumin (ALB) and IgG concentrations in calves from 3 to 14 days postpartum. The addition of TCHMC used in the present study could serve as a potential effective strategy to improve the health and productive performance of periparturient dairy cows, and the optimal dose should be set at 300 g per day.