UNASSIGNED: Fermented jujube powder (FJP) promotes a balance between the intestinal microflora and immune factors in animals. In this study, we aimed to investigate the effects of FJP on the production performance, nutrient digestion, rumen fermentation, and antioxidant properties of bulls.
UNASSIGNED: Forty Simmental bulls were randomly divided into four groups based on body weight and fed a basal diet with [5, 7.5, or 10% dry matter (DM)] or without FJP. The experimental period was 20 d for adaptation and 60 d for the feeding trial.
UNASSIGNED: Dietary FJP supplementation did not affect DM intake (P > 0.05) but increased the average daily gain quadratically (P = 0.049) and decreased the feed conversion ratio linearly (P = 0.042). FJP quadratically enhanced DM and crude protein digestibility (P = 0.026 and P = 0.041, respectively) and linearly enhanced acid detergent fiber digestibility (P = 0.048). It also increased the total volatile fatty acid concentration quadratically (P = 0.037), acetate molar percentage, and acetate-to-propionate ratio linearly (P = 0.002 and 0.001), and reduced the ammonia nitrogen concentration linearly (P = 0.003). Additionally, xylanase and protease activities and Ruminococcus flavefaciens abundance increased linearly (P = 0.006, 0.018, and 0.009, respectively), and total bacteria, Ruminococcus albus, and Ruminobacter amylophilus abundance increased quadratically (P = 0.047, 0.011, and 0.021, respectively). FJP linearly increased serum total protein concentration and antioxidant capacity (P = 0.003 and 0.018, respectively) and decreased malonaldehyde content (P = 0.006).
UNASSIGNED: FJP supplementation (7.5%) enhanced production performance, nutrient digestion, rumen fermentation, and serum antioxidant capacity in bulls. The improved nutrient digestion may be due to an increase in ruminal microorganisms and total volatile fatty acids from the FJP. High blood antioxidant levels indicate that FJP may preserve proteins, thereby boosting the production performance of bulls.

This study evaluated the impacts of α-amylase (AM) and coated α-amylase (CAM) on bull performance, nutrient digestibility, and ruminal fermentation. This study randomized 60 Holstein bulls of 365 ± 11.5 days of age and 457.5 ± 9.35 kg body weight into three groups: without AM addition, adding AM 0.6 g/kg dry matter (DM), and adding CAM 0.6 g AM/kg DM, separately. This whole experimental period was 80 days, including a 20-day adaptation period and a 60-day data and sample acquisition period. In comparison with the unsupplemented control, dry matter intake (DMI) was unaltered; however, average daily gain (ADG) and feed efficiency (FE) were greater for AM or CAM addition. Bulls receiving AM or CAM supply had greater total-tract nutrient digestibility, ruminal total volatile fatty acids (VFA) content, propionate molar proportion, cellulolytic enzyme and AM activities, and the number of microorganisms. In addition, the activities of AM and trypsin in the jejunum and ileum and glucose, albumin, and total protein concentrations in serum were greater for AM or CAM addition compared to the control. When comparing the supplementation mode of AM, bulls receiving CAM addition had greater ADG and FE. The crude protein and starch digestibility and intestinal AM and trypsin activity were higher, while acid detergent fiber (ADF) digestibility was lower for CAM addition than for AM addition. The lower propionate molar proportion and cellobiase and carboxymethyl cellulase activities, together with Ruminococcus albus, Ruminococcus flavefaciens, and Fibrobacter succinogenes populations were observed for CAM addition compared with AM addition. However, there were greater glucose, albumin, and total protein concentrations in serum after adding CAM. According to the data, the supply of AM improved ADG, nutrient digestion, and rumen fermentation. Notably, the optimum supplementation mode was in the form of CAM in bulls.

Bovine reproduction, including male fertility traits like semen quality, are influenced by a variety of different factors like breed, nutrition, environment, and feeding management. Diet in a crucial determinant, and in this regard although corn silage is generally considered to be a favorable roughage for fattening meat type breeds, it tends to have a negative impact on semen quality. In the current study, alfalfa hay was substituted by corn silage as a roughage source in the diet of bulls to investigate its effects on the fertility of breeding bulls. A feeding trail spanning 140 days was conducted, with semen collection occurring twice a week commencing 60 days after the start of trial. Semen quality parameters, serum antioxidant indexes, sex hormone content in semen, rumen microflora, and sperm transcriptome were characterized. Feeding corn silage enhanced host antioxidant capacity, significantly decreased spermatozoal motility and increased sperm deformity rate in bulls. Furthermore, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) content in semen were significantly decreased (P < 0.05), and the inhibin B (INHB) content was significantly increased (P < 0.01). Feeding corn silage led to significant changes in the diversity of rumen microbiota of cattle at the phylum and genus levels, some of which were significantly correlated with semen quality. Subsequent RNA sequencing indicated that DHH and PITHD1, two genes related to sperm and reproductive development, were differentially expressed, and enrichment analysis also identified several pathways and biological functions relevant to sperm development and reproduction. These results indicate that feeding corn silage modulates semen quality via different pathways. Firstly, corn silage metabolites likely affect the secretion of INHB through the testicular capillaries, which affects semen quality by regulating genes involved in spermatogenesis. Secondly, low lignin content in silage corn appears to reduce abundance of rumen flora that are positively correlated with semen quality. Overall, results indicate that feeding bulls corn silage as the primary source of forage could negatively impact semen quality and may not be appropriate as the primary roughage of forage for breeding bulls.

This study examined the influences of coated folic acid (CFA) and coated riboflavin (CRF) on bull performance, nutrients digestion and ruminal fermentation. Forty-eight Angus bulls based on a randomised block and 2 × 2 factorial design were assigned to four treatments. The CFA of 0 or 6 mg of folic acid/kg DM was supplemented in diets with CRF 0 or 60 mg riboflavin (RF)/kg DM. Supplementation of CRF in diets with CFA had greater increase in daily weight gain and feed efficiency than in diets without CFA. Supplementation with CFA or CRF enhanced digestibility of DM, organic matter, crude protein, neutral-detergent fibre and non-fibre carbohydrate. Ruminal pH and ammonia N content decreased and total volatile fatty acids concentration and acetate to propionate ratio elevated for CFA or CRF addition. Supplement of CFA or CRF increased the activities of fibrolytic enzymes and the numbers of total bacteria, protozoa, fungi, dominant fibrolytic bacteria and Prevotella ruminicola. The activities of α-amylase, protease and pectinase and the numbers of Butyrivibrio fibrisolvens and Ruminobacter amylophilus were increased by CFA but were unaffected by CRF. Blood concentration of folate elevated and homocysteine decreased for CFA addition. The CRF supplementation elevated blood concentrations of folate and RF. These findings suggested that CFA or CRF inclusion had facilitating effects on performance and ruminal fermentation, and combined addition of CFA and CRF had greater increase in performance than CFA or CRF addition alone in bulls.

To evaluate the impacts of guanidinoacetic acid (GAA) and coated folic acid (CFA) on growth performance, nutrient digestion and hepatic gene expression, fifty-two Angus bulls were assigned to four groups in a 2 × 2 factor experimental design. The CFA of 0 or 6 mg/kg dietary DM folic acid was supplemented in diets with GAA of 0 (GAA-) or 0·6 g/kg DM (GAA+), respectively. Average daily gain (ADG), feed efficiency and hepatic creatine concentration increased with GAA or CFA addition, and the increased magnitude of these parameters was greater for addition of CFA in GAA- diets than in GAA+ diets. Blood creatine concentration increased with GAA or CFA addition, and greater increase was observed when CFA was supplemented in GAA+ diets than in GAA- diets. DM intake was unchanged, but rumen total SCFA concentration and digestibilities of DM, crude protein, neutral-detergent fibre and acid-detergent fibre increased with the addition of GAA or CFA. Acetate:propionate ratio was unaffected by GAA, but increased for CFA addition. Increase in blood concentrations of albumin, total protein and insulin-like growth factor-1 (IGF-1) was observed for GAA or CFA addition. Blood folate concentration was decreased by GAA, but increased with CFA addition. Hepatic expressions of IGF-1, phosphoinositide 3-kinase, protein kinase B, mammalian target of rapamycin and ribosomal protein S6 kinase increased with GAA or CFA addition. Results indicated that the combined supplementation of GAA and CFA could not cause ADG increase more when compared with GAA or CFA addition alone.

This study evaluated the effects of rumen-protected folic acid (RPFA) and betaine (BT) on growth performance, nutrient digestion and blood metabolites in bulls. Forty-eight Angus bulls were blocked by body weight and randomly assigned to four treatments in a 2 × 2 factorial design. BT of 0 or 0·6 g/kg DM was supplemented to diet without or with the addition of 6 mg/kg DM of folic acid from RPFA, respectively. Average daily gain increased by 25·2 and 6·29 % for addition of BT without RPFA and with RPFA, respectively. Digestibility and ruminal total volatile fatty acids of neutral-detergent fibre and acid-detergent fibre increased, feed conversion ratio and blood folate decreased with the addition of BT without RPFA, but these parameters were unchanged with BT addition in diet with RPFA. Digestibility of DM, organic matter and crude protein as well as acetate:propionate ratio increased with RPFA or BT addition. Ruminal ammonia-N decreased with RPFA addition. Activity of carboxymethyl cellulase, cellobiase, xylanase, pectinase and protease as well as population of total bacteria, protozoa, Fibrobacter succinogenes and Ruminobacter amylophilus increased with RPFA or BT addition. Laccase activity and total fungi, Ruminococcus flavefaciens and Prevotella ruminicola population increased with RPFA addition, whereas Ruminococcus albus population increased with BT addition. Blood glucose, total protein, albumin, growth hormone and insulin-like growth factor-1 increased with RPFA addition. Addition of RPFA or BT decreased blood homocysteine. The results indicated that addition of BT stimulated growth and nutrient digestion in bulls only when RPFA was not supplemented.