Tannin in Ruminant Nutrition: Review

An evaluation of the effectiveness of sumac and molasses as additives for alfalfa silage: Influence on nutrient composition, in vitro degradability and fermentation quality

This study investigated the effects of sumac and molasses on nutrient composition, in vitro degradability and fermentation quality of alfalfa silage. Alfalfa was ensiled in quadruplicate in vacuum jars untreated group (A) or after the following treatments: sumac group at 10% (AS), molasses group at 5% (AM), and sumac (10%) and molasses (5%) group (ASM). Silos (n = 64) were stored for 0, 21, 45 or 60 days. The results showed that dry matter (DM) contents of the AS, AM and ASM groups were statistically higher than the control group (p < 0.001). Only on the 21st day of fermentation the crude ash content of the AS group was found to be significantly higher than the other groups (p < 0.05). In vitro, DM and organic matter degradation values of the AMS group increased significantly (p < 0.001). A significant decrease in alfalfa silage's pH values was determined with sumac and molasses additives (p < 0.001). The ammonia nitrogen (NH3-N) values of the control, AS, AM and ASM groups at Day 60 were determined as 9.08%, 7.22%, 7.00% and 6.81% respectively (p < 0.05). The water-soluble carbohydrate (WSC) values of all groups on the 60th day were significantly decreased compared to the 0th day (p < 0.001). When the groups were evaluated within themselves, there was a statistically significant difference between the 0th and 60th day lactic acid values. The acetic acid content of the A group on the 60th day was found to be significantly higher than the other groups (p < 0.01). There was a significant decrease in propionic acid levels on Days 21, 45 and 60 compared to Day 0 of fermentation (p < 0.001). The highest butyric acid (BA) level was determined in the A group on the 21st, 45th and 60th days of fermentation (p < 0.05). In conclusion, sumac prevents proteolysis depending on its tannin content. It improves silage fermentation positively thanks to its organic acid content, while the molasses additive is effective in silage fermentation, mainly depending on the WSC level. However, it was determined that neither additive could reduce the silage pH to the appropriate value ranges due to the low doses, and they could not mainly prevent the formation of BA.

Biochemical and protein nutritional potential of mulberry (Morus alba L.) leaf: partial substitution improves the nutrition of conventional protein

BACKGROUND

With the requirements of environmental, cost and economic sustainability, new sources of alternative proteins in the livestock industry are receiving increasing attention. Mulberry (Morus alba L.) leaves are a unique feed resource because of their high protein content and large availability. Therefore, mining sustainable protein suitable for the animal husbandry industry in sericulture resources could achieve a win-win situation.

RESULTS

The protein content in mulberry leaves is 232.10-386.16 g kg-1 , and the mean value of crude fat content is 43.76 ± 8.48 g kg-1 , which has the advantages of protein content and energy. In addition, the average content of phytic acid in mulberry leaves is only 1.88 ± 0.56 g kg-1 , which means that it is not inhibited in terms of nutrient absorption. Meanwhile, the digestibility of protein was Bean pulp > Sample 8 ≈ Alfalfa ≈ Sample 13 ≈ Cottonseed meal > Fish meal, and the β-turn and particle size of mulberry leaf protein are more conducive to digestion in vitro. Furthermore, the protein of Sample 13 had the richest essential amino acids (252.00 g kg-1 ) and the highest essential amino acid index (EAAI), which was superior to conventional feed protein. In addition, the partial substitution of mulberry leaf protein (15%) significantly increased the EAAI value of conventional feed protein. However, to balance nutrition, it is necessary to combine mulberry leaf protein with other proteins to further broaden its application field.

CONCLUSION

Mulberry leaves are a new source of feed protein, which helps to alleviate the two major problems of mulberry resource surplus and feed protein resource shortage. © 2023 Society of Chemical Industry.

Evaluating the effects of tannic acid on rabbit growth performance, digestibility, antioxidant status, intestinal morphology and caecal fermentation and microbiota

The objective of this study was to assess the effects of dietary supplementation with tannic acid (TA) on the growth performance, digestibility, antioxidant status, intestinal morphology and the caecal fermentation and microbiota in rabbits. A total number of 120 Ira rabbits (30 days of age) were randomly allotted to four dietary treatment groups: TA 0 (control), TA 0.75, TA 1.5 and TA 3, administered basal diets with 0, 0.75, 1.5 and 3 g TA/kg of feed for 28 days. Compared to the control group, dietary 3 g TA/kg inclusion decreased the average daily feed intake (p < 0.05). No significant differences were found in the digestibility among the groups (p > 0.05). Serum total antioxidant capacity was significantly higher in the 3 g/kg TA group than in the other groups (p < 0.05). There was a significant increase in the concentration of propionic acid and butyric acid in the 3 g/kg TA group. The addition of TA had no effect on villus height and crypt depth of small intestine (p > 0.05). The 16S rRNA high-throughput sequencing results showed that at the phylum level, dietary 3 g/kg TA increased the abundance of Bacteroidetes in the caecum of rabbits (p < 0.05). Based on the results, dietary TA is effective in antioxidant capacity of rabbits, improving caecal fermentation and optimizing the caecal microflora. However, the appropriate dosage supplementation of TA in rabbits needs further research.

Proanthocyanidins isolated from the leaves of Ficus glomerata evaluated on the activities of rumen enzymes: in vitro and in silico studies

Two new proanthocyanidins (2S:3S)-(-)-epicatechin-(4α→8)4-(2R:3R)-(+)-catechin (Compound 1) and (2R, 3R)-3-O-galloyl-(+)-catechin (4β→8)3-(2R, 3R)-3-O-galloyl-(+)-catechin (Compound 2) were isolated from Ficus glomerata and characterized by ultraviolet spectroscopy (UV), proton nuclear magnetic resonance (1H NMR), 13C NMR, and heteronuclear multiple bond correlation . The bioactivity and drug scores of isolated compounds were predicted using OSIRIS property explorer applications with drug scores of 0.03 (compound 1) and 0.05 (compound 2). Predictive drug scores provided an indication of the compounds' potential to demonstrate desired biological effects. Furthermore, the newly discovered proanthocyanidins tended to interact with protein due to their chemical structure and molecular conformation. With the aim of maintaining this focus, compounds 1 and 2 were subjected to in vitro testing against ruminal enzymes to further explore their potential impact. Both compounds showed significant inhibition activities (p < 0.01) against glutamic oxaloacetic transaminase in both protozoa and bacterial fractions, with an effective concentration (EC50) of 12.30-18.20 mg/mL. The compounds also exhibited significant inhibition (p < 0.01) of ruminal glutamic pyruvic transaminase activity, with EC50 values ranging from 9.77 to 17.38 mg/mL. Furthermore, the inhibition was recorded in R-cellulase between EC50 values of 15.85 and 23.99 mg/mL by both compounds. Additionally, both compounds led to a decrease in protease activity with increasing incubation time and concentration. In conclusion, the results indicate that these novel proanthocyanidins hold the potential to significantly impact rumen enzyme biology. Furthermore, their promising effects suggest that they could be further explored for drug development and other important applications.

Carbohydrates and protein digestive traits in beef cattle grazing fertilised or mixed tropical pasture

This study was performed to investigate the nitrogen (N) and carbohydrate digestive traits of grazing heifers. The experiment was carried out at the Federal University of Lavras. The treatments were a Marandu palisadegrass (Urochloa brizantha [Syn, Brachiaria brizantha] Stapf. A. Rich. cv. Marandu) monoculture fertilised with 150 kg N/[ha ∙ year] (FP) or Marandu palisadegrass mixed pasture with forage peanut (MP). The pastures were grazed by six rumen-cannulated zebu heifers. A double cross-over design was used in four periods. Nutritive value, intake and apparent digestibility of forage, ruminal traits and kinetics and N balance were evaluated. Apparent total-tract digestibility of dry matter (DM) and neutral detergent fibre (NDF) were greater for FP than for MP. There was no effect in apparent total-tract digestibility of N. The estimated intestinal digestibility of nutrients was greater on MP than FP. Even though N intake and faecal N output were greater on MP than FP, there was no effect in urine N output. The N balance tended to be greater on MP than FP. The forage peanut, which contains condensed tannins, decreased ruminal fibre degradation, apparent digestibility and ruminal protein degradation, increased N flow from the rumen. Inclusion of forage peanut in the mixed pasture decreased the ruminal fibre degradability but increased N retention by the animals.

The Antioxidant Activity of Wild-Growing Plants Containing Phenolic Compounds in Latvia

Ethnobotanical reports from Latvia show that Tanacetum vulgare, Calluna vulgaris, Quercus robur, Artemisa absinthium, and Artemisia vulgaris contain phenolic compounds that have antioxidant properties, which can be beneficial in the treatment and prophylaxis of many diseases. The aim of this study was to characterize the phenolic compounds and antioxidant properties of these plants. Plant extracts were prepared using ethanol or acetone and then freeze-dried. Their total phenolic content (TPC), total flavonoid content (TFC), and total tannin content (TTC) were determined and characterized by HPLC. Their antioxidant properties were determined using a DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assay. C. vulgaris herb and T. vulgare leaf extracts contained the highest amounts of flavonoids, but the bark of Q. robur had mostly tannins and phenolic acids. A. absinthium and A. vulgaris had the lowest amounts of polyphenols. When compared using extraction solvents, all acetone extracts had more TPC, more TFC, and better antioxidant activity. All plants contained chlorogenic acid, which contributes to antioxidant properties. The analysed plant extracts could be used in future studies to develop medicinal products with antioxidant properties.

Phytochemicals as Immunomodulatory Molecules in Cancer Therapeutics

Phytochemicals are natural plant-derived products that provide significant nutrition, essential biomolecules, and flavor as part of our diet. They have long been known to confer protection against several diseases via their anti-inflammatory, immune-regulatory, anti-microbial, and several other properties. Deciphering the role of phytochemicals in the prevention, inhibition, and treatment of cancer-unrestrained cell proliferation due to the loss of tight regulation on cell growth and replication-has been the focus of recent research. Particularly, the immunomodulatory role of phytochemicals, which is pivotal in unchecked cell proliferation and metastasis, has recently been studied extensively. The immune system is a critical component of the tumor microenvironment, and it plays essential roles in both preventing and promoting oncogenesis. Immunomodulation includes stimulation, amplification, or inactivation of some stage(s) of the immune response. Phytochemicals and their products have demonstrated immune regulation, such as macrophage migration, nitric oxide synthase inhibition, lymphocyte, T-cell, and cytokine stimulation, natural killer cell augmentation, and NFκB, TNF, and apoptosis regulation. There is a dearth of extensive accounts of the immunomodulatory effects of phytochemicals in cancer; thus, we have compiled these effects with mechanistic aspects of dietary phytochemicals in cancer, highlighting promising candidates and ongoing clinical trials on immunotherapeutic strategies to mitigate oncogenesis.

Improving Shelf Life and Content of Unsaturated Fatty Acids in Meat of Lambs Fed a Diet Supplemented with Grape Dregs

This study was conducted to evaluate the potential effects of dietary grape residue levels on the slaughter indicators, meat quality, meat shelf-life, unsaturated fatty acid content, and expression of fatty acid deposition genes in the muscle of lambs. Sixty 30-month-old male Dorper and Small-Tailed Han F1 hybrid lambs were assigned to a single factor complete randomized trial design and fed with four different diets including 0%, 8%, 16%, and 24% grape dregs, respectively. The findings regarding meat production efficacy in the lambs revealed substantial differences. The control group showed notably lower dressing percentage, carcass weight, net meat weight, meat percentage concerning carcass, meat-to-bone ratio, relative visceral and kidney fat mass, and rib eye area compared to the other groups (p < 0.05). Additionally, the meat shearing force of lambs fed a diet with 16% grape pomace (GP) was significantly higher than that of the 24% GP group (p < 0.05), while the 24 h meat color parameter a* value of the control group was notably higher than that of the 8% GP group (p < 0.05). In addition, compared to the control group, lambs fed with a diet containing 16% GP had higher levels of oleic acid (C18:1n-9c), linoleic acid (C18:2n-6c), behenic acid (C22:0), tricosanoic acid (C23:0), lignoceric acid (C24:0), and conjugated linoleic acid (CLA), at a ratio of ∑CLA/TFA, ∑n-6, ∑MUFA, and ∑PUFA in the longissimus dorsi muscle (p < 0.05), but the reverse case was applicable for Total Volatile Basic Nitrogen (TVB-N) content (p < 0.05). GP supplementation did not substantially affect the expression of stearoyl-CoA desaturase (SCD), peroxisome proliferator activated receptor alpha (PPARα), and peroxisome proliferator-activated receptor gamma (PPARγ) genes (p > 0.05). The findings indicated that incorporating grape dregs in the diets of fattening lambs leads to notable enhancements in meat production and the antioxidant capacity of lamb meat, and effectively extends the shelf life of the meat.

Effects of dietary supplementation with microencapsulated Galla chinensis tannins on growth performance, antioxidant capacity, and lipid metabolism of young broiler chickens

This study aimed to investigate the impacts of dietary supplementation with Galla chinensis tannins (GCT) on the growth performance, antioxidant capacity, and lipid metabolism of young broilers. Overall, a total of 216 healthy 1 day-old broilers were randomly allocated to CON group and GCT group, and provided with a basal diet or a basal diet added with 300 mg/kg microencapsulated GCT, respectively, in a 21 days trial. Our findings indicated that dietary GCT addition had no significant effects (p > 0.05) on growth performance. However, GCT supplementation led to a significant reduction in the total cholesterol (TC) concentration in the serum and liver (p < 0.05). Furthermore, GCT supplementation significantly increased the ratios of high-density lipoprotein (HDL) to low-density lipoprotein (LDL) and HDL to TC in the serum, in addition to elevating the activities of enzymes related to lipid metabolism in the liver (p < 0.05). Dietary GCT addition also improved the antioxidant capacity of the broilers, as evidenced by a significant decrease in the concentration of malondialdehyde in serum and liver (p < 0.05). Additionally, the GCT group exhibited significantly increased expressions of hepatic genes associated with antioxidant enzymes (HO-1, GPX1, SOD2, SIRT1, CPT-1, and PPARα) (p < 0.05), while the mRNA expression of SREBP-1 was significantly decreased (p < 0.05) compared with the CON group. In conclusion, dietary addition of 300 mg/kg microencapsulated GCT improved the antioxidant status and lipid metabolism of broilers without affecting their growth performance.

Effect of grape pomace supplement on growth performance, gastrointestinal microbiota, and methane production in Tan lambs

Grape pomace (GP), a by-product in wine production, is nutritious and can be used as a feed ingredient for ruminants; however, its role in shaping sheep gastrointestinal tract (GIT) microbiota is unclear. We conducted a controlled trial using a randomized block design with 10 Tan lambs fed a control diet (CD) and 10 Tan lambs fed a pelleted diet containing 8% GP (dry matter basis) for 46 days. Rumen, jejunum, cecum, and colon bacterial and archaeal composition were identified by 16S rRNA gene sequencing. Dry matter intake (DMI) was greater (p < 0.05) in the GP than CD group; however, there was no difference in average daily gain (ADG, p < 0.05) and feed conversion ratio (FCR, p < 0.05) between the two groups. The GP group had a greater abundance of Prevotella 1 and Prevotella 7 in the rumen; of Sharpe, Ruminococcaceae 2, and [Ruminococcus] gauvreauii group in the jejunum; of Ruminococcaceae UCG-014 and Romboutsia in the cecum, and Prevotella UCG-001 in the colon; but lesser Rikenellaceae RC9 gut group in the rumen and cecum, and Ruminococcaceae UCG-005 and Ruminococcaceae UCG-010 in the colon than the CD group. The pathways of carbohydrate metabolism, such as L-rhamnose degradation in the rumen, starch and glycogen degradation in the jejunum, galactose degradation in the cecum, and mixed acid fermentation and mannan degradation in the colon were up-graded; whereas, the pathways of tricarboxylic acid (TCA) cycle VIII, and pyruvate fermentation to acetone in the rumen and colon were down-graded with GP. The archaeal incomplete reductive TCA cycle was enriched in the rumen, jejunum, and colon; whereas, the methanogenesis from H2 and CO2, the cofactors of methanogenesis, including coenzyme M, coenzyme B, and factor 420 biosynthesis were decreased in the colon. The study concluded that a diet including GP at 8% DM did not affect ADG or FCR in Tan lambs. However, there were some potential benefits, such as enhancing propionate production by microbiota and pathways in the GIT, promoting B-vitamin production in the rumen, facilitating starch degradation and amino acid biosynthesis in the jejunum, and reducing methanogenesis in the colon.

Effects of Increasing Levels of Total Tannins on Intake, Digestibility, and Balance of Nitrogen, Water, and Energy in Hair Lambs

This study aims to evaluate the effects of increasing tannin levels from Mimosa tenuiflora hay on the intake, digestibility, and balance of nitrogen (N), water, and energy in hair lambs. Thirty-two Santa Ines lambs, at an average age of 150 days and body weight of 26.75 ± 2.29 kg, were randomly assigned to four treatments in a completely randomized design. The treatments consisted of four diets: a control diet, tannin-free, and three diets with increasing levels of total tannin, 26.2, 52.4, and 78.6 g tannin/kg dry matter (DM). Including the total tannins in the lambs' diet led to a quadratic increase in the intake of nutrients, N-retention (g/day), water intake, water absorption and retention, energy intake, and energy excretion in feces and gases. However, the digestibility of crude protein, neutral and acid detergent fibers, and total carbohydrates decreased. It was observed that there is a correlation between the variable nutrient digestibility and N-ingested and the N-absorbed, N-urinary, and N-retained. However, the N-excreted in feces did not correlate with any of the variables studied. It is recommended to include 33 g/kg DM of total natural tannins from Mimosa tenuiflora hay in the diet of hair lambs, as it improves intake, energy balance, dietary N, and body water composition while reducing the excretion of N-urinary and gas emissions to the environment.

Anthelmintic Activity of Tanacetum vulgare L. (Leaf and Flower) Extracts against Trichostrongylidae Nematodes in Sheep In Vitro

Due to the high prevalence of gastrointestinal nematodes in sheep, the growing anthelmintic resistance, and the development of organic farming systems, sustainable alternatives are being sought. One such method is phytotherapy. This study aimed to evaluate the in vitro ovicidal and larvicidal activity of extracts of tansy (Tanacetum vulgare L.) growing in Latvia on gastrointestinal nematodes (Trichostrongylidae) in sheep. The leaves and flowers of the tansy were extracted separately in 70%, 50%, and 30% ethanol and acetone. Six concentrations were prepared from each extract 500 mg/mL, 200 mg/mL, 100 mg/mL, 50 mg/mL, 20 mg/mL, and 10 mg/mL. In vitro egg hatching test and micro-agar larval development test were performed. Extracts of tansy have strong larvicidal activity. The highest percentage of larvae inhibition for most of the extracts was 100%, but for egg inhibition, it was 95.8% for the 200 mg/mL concentration of 50% acetone and 93.3% for the 500 mg/mL concentration of 50% ethanol leaf extracts. All tansy extracts had ovicidal and larvicidal activity against Trichostrongylidae in sheep.

Comparison of Black Tea Waste and Legume Roughages: Methane Mitigation and Rumen Fermentation Parameters

The chemical composition, in vitro total gas and CH₄ production and performance of cattle fed on factory black tea waste (Camellia sinensis) (BTW), alfalfa (Medicago Sativa), sainfoin (Onobrychis sativa) and white clover (Trifolium repens) was investigated. The gas production was quantified at the 24th hour of the incubation process. BTW was found to vary from roughages in chemical composition (p < 0.05). In addition, the roughages differed in terms of nutrient composition and gas production (p < 0.05). In legume roughages, acetic acid (AA), propionic acid (PA), butyric acid (BA), and total volatile fatty acids (TVFA) values ranged from 52.36-57.00 mmol/L, 13.46-17.20 mmol/L, 9.79-12.43 mmol/L, and 79.71-89.05 mmol/L, respectively. In comparison with black tea waste, legume roughages had higher values of AA, PA, BA, and TVFA. Black tea waste contained a higher acetic acid ratio than legume roughages when compared as a percentage. There was a similar ratio of propionic acid to the rate calculated for sainfoin (Onobrychis sativa) and clover (Trifolium repens), and a similar ratio of butyric acid to the ratio determined for alfalfa (Medicago Sativa). The current study shows that the 5.7-6.3% tannin content of black tea waste can be used in ruminant rations with high-quality roughages. Due to the fact that BTW reduces methane emissions from ruminants and eliminates energy waste from them, the environment can be improved. To obtain more reliable results, further animal feeding experiments on legume roughages and BTW are required.

Understanding Animal-Plant-Parasite Interactions to Improve the Management of Gastrointestinal Nematodes in Grazing Ruminants

Grazing systems have great potential to promote animal welfare by allowing animals to express natural behaviours, but they also present risks to the animals. Diseases caused by gastrointestinal nematodes are some of the most important causes of poor ruminant health and welfare in grazing systems and cause important economic losses. Reduced growth, health, reproduction and fitness, and negative affective states that indicate suffering are some of the negative effects on welfare in animals infected by gastrointestinal nematode parasitism. Conventional forms of control are based on anthelmintics, but their growing inefficiency due to resistance to many drugs, their potential for contamination of soil and products, and negative public opinion indicate an urgency to seek alternatives. We can learn to deal with these challenges by observing biological aspects of the parasite and the host’s behaviour to develop managements that have a multidimensional view that vary in time and space. Improving animal welfare in the context of the parasitic challenge in grazing systems should be seen as a priority to ensure the sustainability of livestock production. Among the measures to control gastrointestinal nematodes and increase animal welfare in grazing systems are the management and decontamination of pastures, offering multispecies pastures, and grazing strategies such as co-grazing with other species that have different grazing behaviours, rotational grazing with short grazing periods, and improved nutrition. Genetic selection to improve herd or flock parasite resistance to gastrointestinal nematode infection may also be incorporated into a holistic control plan, aiming at a substantial reduction in the use of anthelmintics and endectocides to make grazing systems more sustainable.

Impact of Co-Ensiling of Maize with Moringa oleifera on the Production of Greenhouse Gases and the Characteristics of Fermentation in Ruminants

The objective of this experiment was to evaluate the impact of maize co-ensiling with increasing percentages of MOL forage on the kinetics of biogas, methane (CH₄), carbon monoxide (CO) and hydrogen sulfide (H₂S) production, as well as the characteristics of ruminal fermentation and CH₄ conversion efficiency, using steers (STI) and sheep (SHI) as inoculum sources. With the STI, the inclusion of MOL reduced (linear: p ≤ 0.0199; quadratic: p ≤ 0.0267) biogas production (mL g^-1 DM incubated and degraded), CH₄ (mL g^-1 DM degraded), CO (mL g^-1 DM degraded), and H₂S (mL g^-1 DM incubated and degraded), without affecting (p > 0.05) the parameters (b = asymptotic gas, c = rate of gas production and Lag = initial delay time before gas production) of CH₄ and H₂S, and the proportion and production of CH₄ per kg of dry matter (DM). In addition, with this inoculum, pH, and dry matter degradation (DMD) increased (linear: p ≤ 0.0060), and although short-chain fatty acids (SCFA) and metabolizable energy (ME) decreased (linear: p < 0.0001; quadratic: p ≤ 0.0015), this did not affect (p > 0.05) the CH₄ conversion efficiency. Meanwhile, with the SHI, the inclusion of MOL only decreased (linear: p ≤ 0.0206; quadratic: p ≤ 0.0003) biogas per dry matter (DM) degraded and increased (linear: p ≤ 0.0293; quadratic: p ≤ 0.0325) biogas per DM incubated, as well as the production (mL g^-1 DM incubated and degraded and g^-1 kg DM) and proportion of CH₄, and CO per DM incubated and degraded. In addition, it did not impact (p > 0.05) on the CH₄ and H₂S parameters, and in the H₂S by DM incubated and degraded, and although it increased (linear: p ≤ 0.0292; quadratic: p ≤ 0.0325) the DMD, SCFA, and ME, it was inefficient (quadratic: p ≤ 0.0041) in CH₄ conversion. It is concluded that regardless of the percentage of MOL, the STI presented the highest values in the production of biogas, CH₄, H₂S, DMD, SCFA, and ME, and the lowest pH, so it turned out to be the most efficient in CH₄ conversion, while with the SHI only the highest production of CO and pH was obtained, and the lowest DMD, SCFA, and ME, so it was less efficient compared to STI.

Compared to antibiotic, feeding peony byproducts can improve growth performance, rumen fermentation, slaughter parameters, and meat quality of lambs

Our objective was to determine effects of feeding lamb's peony byproducts, including stem and leaves (PSL), root (PR), and seeds meal (PSM), on growth, rumen fermentation, slaughter parameters, and meat quality. Sixty-four lambs (14.0 ± 2.1 kg) were allocated into eight treatments based on BW: no additives (CON), 0.15% aureomycin (CONA), low/high levels of PSL (5%/10% PSL replaced 5%/10% Chinese hay), PR (basal diet with 0.5%/1.0% PR), PSM (5%/10% PSM replaced 5%/10% soybean meal). Growth, digestibility, and rumen fermentation had dose responses whereas slaughter parameters, meat quality, or amino acids indexes were not. Peony byproducts increased DMI (p < 0.001) compared to CON, but higher levels were more advantageous (p = 0.003). However, low levels of peony byproducts decreased the NH3 -N concentration, but increased total volatile fatty acids mole percent more than high levels of that (p < 0.001). All peony byproducts increased dressing percentage (p < 0.05), increased pH and tenderness than CON (p < 0.05). In addition, PSL and PSM improved amino acid profiles of meat compared to CON, and were even better than CONA (p < 0.05). Therefore, peony byproducts not only improved animal growth but also reduced the frequency of antibiotic use in animal feeding.