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Although studies have revealed the significant impact of dietary fiber on growth performance and nutrient digestibility, the specific characteristics of the intestinal microbiota and gene regulation in pigs capable of digesting high-fiber diets remained unclear. To investigate the traits associated with roughage tolerance in the Chinese indigenous pig breed, we conducted comparative analysis of growth performance, apparent fiber digestibility, intestinal microbiota, SCFA concentrations and intestinal transcriptome in Tunchang pigs, feeding them diets with different wheat bran levels. The results indicated that the growth performance of Tunchang pigs was not significantly impacted, and the apparent total tract digestibility of crude fiber was significantly improved with increasing dietary fiber content. High-fiber diets altered the diversity of intestinal microbiota, and increased the relative abundance of Prevotella, CF231, as well as the concentrations of isobutyrate, valerate and isovalerate. The LDA analysis identified potential microbial biomarkers that could be associated with roughage tolerance, such as Prevotella stercorea, and Eubacterium biforme. In addition, appropriate high-fiber diets containing 4.34% crude fiber upregulated the mRNA expressions of PYY, AQP8, and SLC5A8, while downregulating the mRNA expressions of CKM and CNN1.This indicated that appropriate high-fiber diets may inhibit intestine motility and increase the absorption of water and SCFAs.

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The Jinwu pig (JW) is a hybrid breed originating from the Chinese indigenous Jinhua pig and Duroc pig, boasting excellent meat quality and fast growth rates. This study aimed to verify the tolerance of JW to roughage, similar to most Chinese indigenous pigs. In this research, two types of feed were provided to JW and Duroc × Landrace × Yorkshire pigs (DLY): a basal diet and a roughage diet (increasing the rice bran and wheat bran content in the basal diet from 23% to 40%) for a 65-day experimental period. The roughage diet showed an increasing trend in the feed conversion ratio (F/G), with a 17.61% increase in feed consumption per unit weight gain for DLY, while the increase for JW was only 4.26%. A 16S rRNA sequencing analysis revealed that the roughage diet increased the relative abundance of beneficial bacteria, such as Lactobacillus and Clostridium, while reducing the relative abundance of some potential pathogens, thus improving the gut microbiota environment. After being fed with the roughage diet, the abundance of bacterial genera, such as Treponema, Terrisporobacter, Coprococcus, and Ruminococcaceae, which aid in the digestion and utilization of dietary fiber, were significantly higher in Jinwu compared to DLY, indicating that these bacterial genera confer Jinwu with a higher tolerance to roughage than DLY.

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Dairy buffaloes are typically fed a high-forage, low-quality diet with high fiber. These conditions result in an inherent energy and protein inefficiency. In order to make full and rational use of feed resources and improve the production level and breeding efficiency of dairy buffaloes, the effects of various roughages on nutrient digestibility, ruminal fermentation parameters, and microorganisms in dairy buffaloes were studied in this experiment. Three ternary hybrid buffaloes, with an average body weight of 365 ± 22.1 kg, were selected and fitted with permanent rumen fistulas. They were fed six different diets, each consisting of 1 kg concentrate supplement and one of six types of roughage, including alfalfa hay (A diet), oat hay (O diet), whole corn silage (W diet), king grass (K diet), sugarcane shoot silage (S diet), and rice straw hay (R diet) according to an incomplete Latin square design of 3 × 6, respectively. The pre-feeding period of each period was 12 d. From day 13 to 15 was the official experimental period. During the prefeeding period, free feed intake for each roughage was determined, and during the experiment, the roughage was fed at 90% of the voluntary feed intake. Digestion and metabolism tests were carried out using the total manure collection method to determine the feed intake and fecal output of each buffalo, and to collect feed and fecal samples for chemical analysis. On day 15, rumen fluid samples were collected two hours after morning feeding to determine rumen fermentation parameters and bacterial 16 S rRNA high-throughput sequencing was performed. The results showed that DM and OM digestibility were greatest for the W diet and lowest for the S diet. The rumen pH of the O diet was significantly greater than that of the W diet. The concentration of rumen fluid NH3-N (mg/dL) increased with increased CP content. The concentration of total volatile fatty acids (mmol/L) in the rumen decreased with increased NDF content but increased with increased NFC content. The relative abundances of Bacteroidetes, Firmicutes, and Spirochaetes were 57.03-74.84%, 14.29-21.86%, and 0.44-1.43% in the different quality roughage groups. Bacteroidetes were mainly Prevotellaceae1 and Rikenellaceae RC_gut_group with relative abundances of 30.17-45.75% and 3.23-7.82%. The relative abundance of Patescibacteria and Spirochaetes decreased with increasing roughage quality. These results provide a theoretical and practical basis for evaluating the nutritional value of dairy buffalo feed, utilizing feed resources, matching rations, feeding scientifically, and protecting animal health.

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We hypothesized that cottonseed cake in confined Nellore young bulls' diet as fiber source, could maintain or improve the nutrient intake, and productive and metabolic parameters. It was evaluated the total replacement of whole plant corn silage (WPCS) by cottonseed cake (CSC) as a source of fiber in the diet. A completely randomized design with two treatments and 12 replications was used. The treatments were two experimental diets containing 300 g/kg of WPCS or CSC as roughage. All animals at 0, 15, 30, 60 and 112 days were weighed to monitor productive performance and nutrient intake. Dry matter intakes, organic matter, neutral detergent fiber, physically effective neutral detergent fiber, crude protein and non-fiber carbohydrates of the WPCS treatment cattle were higher (p < 0.05), and the ethereal extract intake of cattle fed CSC diet was higher. The BW of cattle fed WPCS was higher in the two initial periods of confinement (p < 0.05). Animals from both treatments showed linear growth during the confinement period. There was a fiber source × period interaction for total weight gain (TWG), average daily gain (ADG) and feed efficiency (FE) (p < 0.05), with the lowest in the first 15 days and the highest at 30 days, reflecting a compensatory gain in animals fed with CSC. Bulls fed with CSC showed negative TWG and ADG in the first period (p < 0.05), but recovered in the following periods, surpassing that of the SC treatment in the last two periods. There was negative EF of bulls fed with CSC in the first period (P < 0.05), but in the following periods the CSC diet did not differ from the WPCS diet. The animals fed CSC diet showed a higher concentration of cholesterol and glucose in the blood plasma (p < 0.05). The forage-free diet containing cottonseed cake as a source of fiber replacing corn silage promoted better animal performance.

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Limited access to high-quality feed protein for pigs has made it necessary to evaluate new protein sources that both promote sustainable pig production and meet the nutritional requirements of pigs. Providing pigs with roughage has positive effects on their behaviour and gut health. However, roughage is seldom given as a part of the pigs' diet and often has a long straw length. Knowledge is lacking on the effect of feeding silage with smaller particle size and as a part of the pigs' diet on pig behaviour and welfare. This study evaluated the influence of feeding fattening pigs silage with different particle sizes on aggressive encounters, measured as the number of skin lesions, and on the occurrence of gastric lesions and ulcers. In total, 128 Swedish Yorkshire × Hampshire pigs were fed either a commercial control feed without silage (Pellet-C), or silage mixed with commercial feed, either in a pellet (Pellet-S) or in a total mixed ration (TMR) with chopped (TMR-Ch) or intensively treated silage (TMR-Ex). Skin lesions were assessed twice in the study according to the Welfare Quality® protocol. The first assessment was performed when the pigs were 105 days old and the second assessment at 132 days of age. Gastric lesions were examined in both the pars oesophagea and the pars glandularis region of the stomach. Stomachs were collected after slaughter, and gastric lesions were scored based on established scoring criteria. There was a treatment × assessment interaction on the number of skin lesions on the ear (P = 0.049). Apart from this interaction, no other effect of treatment on the number of skin lesions could be observed between the treatments or the assessment occasions. Treatment had a clear effect on the occurrence of gastric lesions and pigs fed the fresh silage (TMR-Ch and TMR-Ex) had a lower occurrence of gastric lesions and ulcers compared to the pelleted treatments (Pellet-C and Pellet-S) (P = 0.001). This study could not show any clear reduction effect of dietary silage inclusion on skin lesions. However, feeding silage in TMR significantly reduced the occurrence of stomach ulcers.

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This study evaluated the effect of different fiber sources supplied with cactus cladodes in diets on the intake and digestibility of nutrients, ingestive behavior, milk yield, and composition of dairy goats. The fiber sources were corn silage, sorghum silage, Digitaria pentzii Stent. hay, and sugarcane bagasse. Twelve Saanen goats with an average weight of 48.9 ± 7.3 kg and average production of 2.8 ± 0.7 kg of milk/day were assigned in three simultaneous 4 × 4 Latin squares (four animals, four treatments, and four experimental periods). There was no difference between the fiber sources for intake (P > 0.05) of dry matter (2.58 kg/day), organic matter (2.30 kg/day), crude protein (0.385 kg/day), neutral detergent fiber (0.895 kg/day), non-fibrous carbohydrates (0.858 kg/day), and metabolizable energy (5.66 Mcal/day). Also, the fiber sources did not influence dry matter and nutrient digestibility (P > 0.05). The association of cactus cladodes with silages, hay, and sugarcane bagasse did not change milk production, milk production corrected for 3.5% of fat and corrected for energy (2.78; 2.53 and 2,55 kg/day, respectively), in addition to milk composition (P > 0.05). No differences were observed in ingestive behavior (P > 0.05). Any fiber sources evaluated are recommended.

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Peanut vine is a typical peanut by-product and can be used as a quality roughage resource. Whole-plant corn silage is a commonly used roughage. However, few studies have investigated the effects of diets combining peanut vine and whole-plant corn silage on growth performance, antioxidant capacity, meat quality, rumen fermentation and microbiota of beef cattle. To investigate these effects, eighty Simmental crossbred cattle (body weight, 451.27 ± 10.38 kg) approximately 14 months old were randomly divided into four treatments for a 90-day feeding experiment. A one-way design method was used in this experiment. According to the roughage composition, the cattle were divided into a control treatment of 45% wheat straw and 55% whole-plant corn silage (WG), and three treatments of 25% peanut vine and 75% whole-plant corn silage (LPG), 45% peanut vine and 55% whole-plant corn silage (MPG), and 65% peanut vine and 35% whole-plant corn silage (HPG), and the concentrate was the same for all four treatment diets. The results showed that compared to the WG group, the MPG group experienced an increase in their average daily feed intake of 14%, an average daily gain of 32%, and an increase in SOD activity in the spleen of 33%; in the meat, dry matter content increased by 11%, crude protein by 9%, and ether extract content by 40%; in the rumen, the NH3-N content was reduced by 36%, the relative abundance of Firmicutes increased, and the relative abundance of Bacteroidetes decreased (p < 0.05). These results showed the composition of 45% peanut vine and 55% whole-plant corn silage in the roughage improved growth performance, antioxidant capacity, meat quality, rumen fermentation, and microbiota of beef cattle.

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Current dogma suggests increased dietary roughage may improve calf health at the expense of performance during receiving. In experiment 1, the effects of increasing dietary roughage on performance and clinical health of high-risk heifers was evaluated over a 56-d receiving period. Heifers (n = 589; initial body weight; BW = 230 ±â€…33 kg) were sourced from Oklahoma livestock auctions from April through October of 2019. Heifers were randomly assigned to pens, which were randomly assigned to 1 of 3 experimental dietary treatments in a randomized complete block design. Diets contained either: 1) 15% roughage (R15), 2) 30% roughage (R30), or 3) 45% roughage (R45) in the form of prairie hay. Orthogonal contrasts were used to test for linear and quadratic responses among experimental treatments. There was a linear decrease in overall average daily gain (ADG; P ≤ 0.0001) with increasing roughage inclusion which resulted in a linear decrease (P ≤ 0.0001) in heifer final BW. A linear increase (P ≤ 0.01) was observed for overall dry matter intake (DMI), and overall gain:feed (G:F) decreased linearly (P ≤ 0.0001) as dietary roughage concentration increased. A quadratic response to decreasing roughage was observed (P = 0.02) for the percent of calves treated three times for bovine respiratory disease (BRD). No other responses (P ≥ 0.11) were detected in animal health variables. In experiment 2, Angus steers (n = 12) and heifers (n = 6; BW = 272 ±â€…28 kg) were acquired from a single ranch in Oklahoma to evaluate the same experimental dietary treatments on serum metabolite concentrations. Animals were randomly assigned to experimental treatments, with animal serving as the experimental unit in experiment 2. Statistical models for serum metabolites in experiment 2 were analyzed using repeated measures with the effects of treatment, time, and treatment × time. In experiment 2, there were tendencies for treatment × time interactions for blood urea nitrogen (BUN; P = 0.07) and nonesterified fatty acid (NEFA; P = 0.06) concentrations. No metabolites were affected by treatment (P ≥ 0.11), while all metabolites were impacted by time (P ≤ 0.02). In summary, growth performance was improved in calves as dietary roughage concentration decreased with minimal impacts on health and serum metabolites. These results suggest that diets containing as little as 15% roughage can be used during receiving to improve calf performance without compromising calf health when fibrous byproducts are included in the diet.

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The lipid molecules and volatile organic compounds (VOCs) in milk are heavily influenced by diet. However, little is known about how roughage affects the lipid and VOC contents of donkey milk. Accordingly, in the present study, donkeys were fed corn straw (G1 group), wheat hulls (G2 group), or wheat straw (G3 group), and the lipid and VOC profiles of their milk were determined using LC-MS and GC-MS. Of the 1842 lipids identified in donkey milk, 153 were found to be differential, including glycerolipids, glycerophospholipids, and sphingolipids. The G1 group showed a greater variety and content of triacyclglycerol species than the G2 and G3 groups. Of 45 VOCs, 31 were identified as differential, including nitrogen compounds, esters, and alcohols. These VOCs were significantly increased in the G2 and G3 groups, with the greatest difference being between the G1 and G2 groups. Thus, our study demonstrates that dietary roughage changes the lipid and VOC profiles of donkey milk.

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Corn straw and corncobs contain large amounts of crude fibers and are widely used in mutton sheep husbandry in northwest China. The aim of this study was to determine whether feeding with corn straw or corncobs affects lamb testis development. A total of 50 healthy Hu lamb at two-month-old (average body weight of 22.3 ± 0.1 kg) were randomly and equally divided into two groups, and the lambs were equally allocated to five pens in each group. The corn straw group (CS) received a diet containing 20% corn straw, whereas the corncobs group (CC) received a diet containing 20% corncobs. After a 77-day feeding trial, the lambs, except the heaviest and lightest in each pen, were humanely slaughtered and investigated. Results revealed no differences in body weight (40.38 ± 0.45 kg vs. 39.08 ± 0.52 kg) between the CS and CC groups. Feeding diet containing corn straw significantly (P < 0.05) increased testis weight (243.24 ± 18.78 g vs. 167.00 ± 15.20 g), testis index (0.60 ± 0.05 vs. 0.43 ± 0.04), testis volume (247.08 ± 19.99 mL vs. 162.31 ± 14.15 mL), diameter of seminiferous tubule (213.90 ± 4.91 µm vs. 173.11 ± 5.93 µm), and the number of sperm in the epididymis (49.91 ± 13.53 × 108/g vs. 19.34 ± 6.79 × 108/g) compared with those in the CC group. The RNA sequencing results showed 286 differentially expressed genes, and 116 upregulated and 170 downregulated genes were found in the CS group compared with the CC group. The genes affecting immune functions and fertility were screened out. Corn straw decreased the mtDNA relative copy number in the testis (P < 0.05). These results suggest that compared with corncobs, feeding corn straw in the early reproductive development stage of lambs increased the testis weight, diameter of seminiferous tubule and the number of cauda sperm.

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BACKGROUND: Chewing is an essential physiological process in horses; yet, the physical form of feeds may affect their chewing and feeding behaviour with consequences for equine digestion and health. OBJECTIVES AND METHODS: The present study evaluated the potential of a commercial forage cubes made from alfalfa and mixed meadow grasses to maintain chewing activity when compared with a traditional long and fibre-rich hay. An additional aim was to measure the dust formation during feeding. The experiment was a crossover design with six horses (11 ± 4 years old, mean ± SD), fed with 5 kg (as-fed basis) of their feed (long hay or alfalfa cubes) overnight. Eating and chewing activity was measured using the EquiWatch system with a sensor-based halter. RESULTS: Data showed that by feeding the same amount of feed overnight, cube feeding led to 24% shorter eating time (on average 67 min less) and 26% fewer total chews compared to the long hay. On an hourly basis, horses also spent more time eating and chewing the long hay compared to the cubes. The cube feeding led to a higher dust concentration of the inhalable fraction (<100 µm), but not of the thoracic (<10 µm) fraction. Nevertheless, average dust concentrations were generally low for both cubes and hay, whereby both were of sound hygienic status. CONCLUSION AND RECOMMENDATION: Our data suggest that feeding alfalfa-based cubes overnight generated shorter eating time and less chews than the long hay without major differences in the thoracic dust. Therefore, because of the decreased eating time and chews, alfalfa-based cubes should not be fed a sole forage source, especially when it is to be fed without restriction.

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BACKGROUND: The nutrient availability of roughages could affect the dietary utilization efficiency of ruminants even in isocaloric and isonitrogenous diets. Here, we analyzed the bacterial composition and their metabolic pathways in the gastrointestinal tracts (GITs) of Hu sheep fed with wheat straw (WS) instead of alfalfa (AL) in isocaloric and isonitrogenous diets, trying to explore the reasons from the perspective of GITs bacterial network structure changes. RESULTS: We employed 16S rRNA gene sequencing in combination with the Kruskal-Wallis test, Spearman correlation analysis, and other statistical methods to describe the microbiota composition in the GITs of Hu sheep. The results showed after the roughage was replaced from AL to WS, the most positive response occurred in the rumen microbiota, resulting in a more obvious microbiological and functional redundancy phenomenon. Whereas extended biogeographic studies of the GITs bacterial community found opposite results for the hindgut microbiota and metabolism networks compared to the forestomach. The abundance of fiber-degrading bacteria such as Prevotella, Oscillospiraceae NK4A214 group, and Treponema was significantly increased in GITs, but low-efficiency crude fiber degradation inhibited energy use efficiency, the pentose phosphate pathway, gluconeogenesis, and volatile acid synthesis. In addition, dietary shifting from AL to WS decreased the abundance of beneficial bacteria such as the Lachnospiraceae NK3A20 group and Alistipes, thereby enhancing the underlying inflammatory response. CONCLUSIONS: These findings suggest that feeding untreated WS affected the structure and function of the bacterial network in the GITs due to limited total digestible nutrients, and in particular increases the complexity of the rumen bacterial network, and limit the abundance of bacteria involved in the crude fiber degradation in the hindgut.

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The purpose of the current study is to determine the effects of the replacement of cassava chips with winged bean (Psophocarpus tetragonolobus) tubers (WBTs) on gas production parameters, in vitro degradability, and ruminal fermentation in ruminant diets. The study was performed using a 3 × 4 factorial arrangements and was designed using a completely random method. Factor A employed three various roughage sources that were frequently used by locals to feed ruminants: Oryza sativa L. (a1), Brachiaria ruziziensis (a2), and Pennisetum purpureum (a3). The levels of WBTs substitutions for cassava chips at 0%, 33%, 66%, and 100% in the diet were selected as factor B. The experiment's findings revealed that replacing the cassava chips in the diet with WBTs at levels of 66 and 100% enhanced the fermentation process by producing a high gas volume at 96 h when Ruzi grass (RZ) was used as the main source of roughage (p < 0.01). The interaction between the roughage source and WBTs showed that organic matter (OM) degradability improved markedly in the case of RZ grass in combination with WBTs at all levels. Both the total volatile fatty acids (TVFAs) at 8 h of incubation and the average value decreased when a complete substitution of casava chips with WBT (WBT 100%) was employed or when employing rice straw as the main source of roughage (p < 0.01). There was no interaction between WBTs and roughage source on the ammonia-nitrogen (NH3-N) concentration (ml/dL) and rumen microbial count (p > 0.05). In summary, WBTs can be used effectively when combined with grass (Ruzi and Napier). The implementation of WBTs as a novel alternative feed may effectively replace cassava chips without affecting rumen function.

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This study evaluated the effects of forages (BarS vs. STR) that differ in the uNDF concentration and FI rate on ruminal fermentation, total tract barrier function, reticulo-ruminal motility, and blood metabolites of beef heifers. Six ruminally cannulated Hereford × Simmental heifers (699 ± 69.1 kg BW) were used in a 6 × 6 Latin square (26 d periods) with a 2 × 3 factorial treatment arrangement. However, 1 heifer was removed from the study after period 2 due to health problems unrelated to treatment, resulting in an incomplete 6 × 6 Latin square design. Barley grain-based diets were formulated using BarS or wheat STR to alter uNDF (7.1% vs. 8.5% DM) with FI rates of 5%, 10%, or 15% of DM. There were limited interactions between the forage type and FI. DM intake was not affected (P ≥ 0.10) by forage type or FI. Use of STR vs. BarS increased uNDF intake (P < 0.001). Increasing FI increased (P < 0.001) uNDF intake for those fed 15% forage. Ruminal pH was not affected (P ≥ 0.10) by forage type; however, cattle fed 5% FI had lesser (P = 0.017) mean ruminal pH and maximum pH (P = 0.018) than those fed 10% and 15% of forage. The total SCFA concentration was not affected by forage type (P = 0.84) but cattle fed the 5% FI rate had lesser (P < 0.001) molar proportion of acetate when compared with cattle fed 10% and 15% forage. Increasing the FI rate decreased the molar proportion of propionate (P < 0.001). Feeding STR relative to BarS decreased (P = 0.041) the reticulo-ruminal contraction duration. In contrast, cattle fed the 10% and 15% FI rates had a greater (P = 0.028) contraction frequency with lower (P = 0.048) contraction area than those fed 5% forage. Plasma glucose, serum insulin, and serum amyloid A were not affected by forage type or FI rate (P ≥ 0.10). Cattle fed 15% forage had lesser (P = 0.040) concentration of serum haptoglobin when compared with cattle fed 5% or 10% forage. In conclusion, forage type used to affect the dietary uNDF concentration, and FI rate act independently suggesting that the provision of STR to increase uNDF reduces reticulo-ruminal contraction duration and total tract permeability but may not affect ruminal pH. Increasing the FI increased dietary uNDF, stabilized ruminal pH, stimulated more frequent reticulo-ruminal contractions, and may decrease the permeability of the gastrointestinal tract and systemic inflammation.

As a strategy to improve performance, feedlot cattle are often fed diets containing a high proportion of grain with minimal forage. However, diets with insufficient fiber may predispose cattle to nutritional disorders, such as ruminal acidosis, which leads to poor performance and increases production costs. Given the growing concern regarding minimal fiber requirement, the present study was designed to investigate the effects of forages differing in undigested neutral detergent fiber (uNDF; barley silage [BarS] vs. straw [STR]) concentration and forage inclusion (FI) rate (5%, 10%, or 15% of dietary dry matter [DM]) on reticulo-ruminal motility and fermentation, total tract barrier function, and blood metabolites of beef cattle. The inclusion of STR increased uNDF intake and rumination rate, but decreased reticulo-ruminal contraction duration, with no effect on ruminal pH and total short-chain fatty acid (SCFA) concentration. Decreasing the FI rate decreased uNDF intake, ruminating time, ruminal pH, and reticular contraction frequency, but increased the molar proportion of propionate and concentration of serum haptoglobin. In conclusion, forage type and FI rate act independently suggesting that providing forages that increase dietary uNDF may stimulate the frequency of reticulo-ruminal contractions without affecting ruminal pH. However, increasing FI inadvertently increased dietary uNDF, stabilized ruminal pH, increased rumination time, stimulated ruminal contractions, and decreased indicators of systemic inflammation.

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Dietary forage levels contribute to the performance of non-nutritive oral behaviors (NNOB) in cattle, yet the impact of varying forage levels on these behaviors is unknown. To evaluate the impact of dietary corn stalk inclusion (CSI) levels on NNOB, rumination time, and activity, pre-dominantly British-continental crossbred drylot-housed steers (n=27) were blocked by weight and randomly assigned to one of three dietary treatments (5%, 10%, or 15%) of CSI on a DM basis. Animals were fitted with a rumination collar upon arrival that measured rumination time and activity and video recorded. Cattle that spent more time bar licking had greater DMI, tended to have greater ADG and be more active. CSI in this study did influence NNOB performance; however, the impacts observed were not as expected. Cattle fed the 10% CSI performed the most bar licking and tongue rolling. This pilot investigation suggest that these CSI were insufficient to have a meaningful impact on NNOBs. Cattle spending more time bar licking and bar licked more frequently may be more orally motivated as reflected in their increased DMI and activity levels.

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A pooled analysis was performed to evaluate whether corn silage fed at 15% or 45% of diet DM impacted liver abscesses prevalence at slaughter in five previous experiments. Cattle fed 15% corn silage had 7.8% abscessed livers compared to 4.1% for cattle fed 45% corn silage when all diets contained tylosin. While improved due to increased corn silage inclusion, the objective of the current finishing study was to determine the impact of silage inclusion in finishing diets with and without tylosin on performance and incidence of abscessed livers in beef cattle. A total of 640 (BW = 334 ± 25 kg) steers were used in a generalized randomized block design with a 2 × 2 factorial treatment design. Treatments included two concentrations of corn silage (15% and 45% of diet DM), with or without tylosin for liver abscesses. This study used 32 pens of cattle with 20 steers per pen and 8 pens per treatment. There was a tendency for an interaction for feed efficiency (G:F; P = 0.10) where cattle fed 15% corn silage had a 2% increase in G:F when tylosin was added to the diet, but no improvements in G:F were observed when tylosin was added to diets containing 45% silage. There was an interaction between silage and tylosin inclusion for abscessed livers (P = 0.05). Cattle fed 15% corn silage without tylosin had the greatest incidence of abscessed livers (34.5%) compared to other treatments (P = 0.05), and the incidence of abscessed livers was decreased to 19% if tylosin was fed with 15% corn silage. Feeding 45% silage was effective at lowering the incidence of abscessed livers (P = 0.05) which was 12.4%, regardless of whether tylosin was fed. Feeding corn silage at 45% of diet DM (77.5% concentrate) was as effective as feeding tylosin to cattle on a 92.5% concentrate diet. Feeding corn silage at greater inclusions decreased daily gain (P ≤ 0.01) but increased final body weight when fed to an equal fatness (cattle fed 45% CS were fed 28 d longer). Feeding corn silage at 45% was more economical compared to feeding 15% corn silage, especially as corn prices increase, provided shrink is well managed. Feeding elevated concentrations of corn silage may be an economically viable method to reduce incidence of liver abscesses without antibiotic use for smaller operations that can manage more corn silage in finishing diets.

Antibiotics are a very effective method to control liver abscesses for finishing cattle, which are thought to be due to high starch concentration and acidosis. Dietary roughage (forage) is used to control acidosis. As grain prices increase, feeding greater amounts of corn silage may be advantageous and silage can be an economical forage compared to other traditional forages like alfalfa. This study evaluated the impact of corn silage inclusion on performance and abscessed livers with and without the addition of antibiotics. As expected, feeding more corn silage decreased both gain and feed efficiency but also increased profitability. Feeding tylosin with a traditional inclusion of silage (15%) decreased abscessed livers from 34.5% to 19%. However, if cattle are fed more silage (45%) the incidence of abscessed livers was 12.4%, regardless of feeding tylosin or not.

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The objective of this experiment was to determine the influence that similar dietary roughage equivalency offered in a single or two-diet system during a 210-d growing-finishing period has on growth performance, the efficiency of dietary net energy (NE) utilization, and carcass traits in beef steers. Beef steers (n = 46; initial shrunk [4%]; body weight [BW] = 281 ± 40.4 kg) were fed once daily, and bunks were managed according to a slick bunk management system across all 10 pens. Treatments included the following: 1) A single diet program that was formulated to provide 16% (dry matter [DM] basis) dietary roughage equivalency; SD) or 2) multiple diet programs (formulated to provide a dietary roughage equivalency (DM basis) of 25% for 98 d, 16% for 14 d, and 7% for 98 d; MD). Day 1 to 112 was considered the growing period, and day 113 to 210 (the day of harvest) was considered the finishing period, all steers were implanted on day 1 with a 100 mg trenbolone acetate (TBA) and 14 mg estradiol benzoate (EB) implant and implanted with a 200 mg TBA and 28 mg EB implant on day 112. Average daily gain tended (P = 0.06) to be 9.5% greater for SD compared to MD during the growing portion, and average daily gain (ADG) was greater by 11.3% (P = 0.01) for MD compared to SD during the finishing phase of the experiment. Cumulative ADG did not differ (P ≥ 0.86) between treatments (1.61 vs. 1.62 ± 0.046 kg) for SD and MD, respectively. Cumulative dietary NEm and NEg calculated based on performance did not differ (P ≥ 0.96) between treatments. There were no differences (P ≥ 0.18) detected between treatments for hot carcass weight, dressing percent, longissimus muscle area, rib fat, United States Department of Agriculture (USDA) marbling score, kidney, pelvic, heart fat, yield grade, retail yield, empty body fat, or body weight at 28% estimated empty body fat. These data indicate that feedlot producers can feed a single growing-finishing diet to beef steers with minimal effects on overall growth performance or carcass traits.

We aimed to determine the influence of feeding a dietary roughage equivalency in a single or multiple diet system during a 210-d growing-finishing period on growth performance and carcass traits of beef steers. Cumulative average daily gain did not differ between treatments. Also, there were no differences detected between treatments for any carcass traits. Feedlot producers can feed a single "grow-finish" diet to weaned beef steers with minimal effects on overall growth performance or carcass traits. Feeding a single diet during both the growing and finishing phases could be used as a strategy to simplify management by reducing the number of diets fed, or as a way to use ensiled roughages more rapidly to reduce feed-out losses during summer months.

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Dietary mix and host species have both been shown to have a significant impact on rumen microbial diversity, enteric methane emission and animal performance. The goal of this study was to see how the roughage concentrate ratio 70:30 (Low concentrate; LC) vs 40:60 (High concentrate; HC) and the host species crossbred cattle vs buffalo affected rumen microbial diversity, enteric methane emissions and nutrient utilization. Dry matter intake (kg/d) and dry matter percent digestibility were considerably (p < 0.05) higher in the HC ration and buffalo compared to LC ration and crossbred cattle, respectively. Both dietary mix and host species had a substantial (p < 0.05) impact on intake of various nutrients, including organic matter (OM), crude protein (CP), ether extract (EE), neutral detergent fiber (NDF), and acid detergent fiber (ADF). Increased concentrate proportion in the ration improved nitrogen balance, resulting in increased average daily gain and considerably reduced methane (g/d) output (p < 0.05). Furthermore, 16S rRNA genes were sequenced using Oxford Nanopore Technology (ONT) and subsequently annotated using the Centrifuge workflow to uncover ruminal bacterial diversity. Firmicutes was considerably (p < 0.01) greater in the LC diet, whereas, Bacteroidetes was higher in the HC ration. Genus Prevotella dominated all rumen samples, and buffalo fed LC ration had significantly (p < 0.01) higher Oscillospira abundance. At the species level, simple sugar-utilizing bacteria such as Prevotella spp. and Selenomonas ruminantium predominated in the crossbred cattle, but fibrolytic bacteria such as Oscillospira guilliermondii were statistically (p < 0.01) more abundant in the buffalo. Overall, dietary mix and host species have both been shown to have a significant impact on rumen microbial diversity, enteric methane emission and animal performance, however, host species remained a major driving force to change ruminal community composition as compared to roughage concentrate ratio under similar environmental conditions.

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OBJECTIVE: Recently, indigenous Korean grass Sasa quelpaertensis Nakai (SQ) has garnered much interest as a roughage source for livestock to mitigate its adverse effects on habitat diversity. Thus, the objective of the present study was to evaluate the ruminal fermentation, palatability, and nutrient digestibility of SQ for Korean native beef cattle (Hanwoo) using in vitro rumen fermentation, in situ rumen degradability, and in vivo feeding trials. METHODS: Using in vitro tests with rumen fluid as the inoculum for 48 h, ruminal fermentation of SQ was evaluated and compared with that of other roughage sources commonly used in Korea (i.e., rice straw, Timothy hay, and Italian ryegrass [IRG]). Additionally, an in situ trial 96 h was performed using three cannulated Hanwoo steers. Further, an in vivo trial was performed using eight Hanwoo steers to compare the palatability of SQ with rice straw in total mixed ration (TMR) and forage-concentrate separate feeding conditions. Finally, an in vivo digestibility trial of SQ fed as TMR of two particle sizes was performed with four Hanwoo steers. RESULTS: In vitro and in situ trials revealed that SQ was comparable or superior to rice straw in terms of the ruminal fermentation characteristics of pH, gas production, total volatile fatty acid content, and effective ruminal dry matter digestibility (DMD), although its fermentability was lower than that of Timothy hay and IRG. In the palatability test, steers showed a greater preference for SQ when given as TMR. The total tract DMD of SQ fed as TMR was 75.9%±1.37%, and it did not differ by particle size. CONCLUSION: The feed value of SQ as a roughage source for Hanwoo steers is comparable or superior to that of rice straw, particularly when provided as TMR.

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Many researchers have evaluated different nonantibiotic, dietary interventions to reduce liver abscessation including degree of grain processing, roughage particle size, ionophore inclusion level, and supplemental prebiotics or probiotics; however, these alternatives have been inconsistent in outcomes and have not proven to be successful. New technologies and methodologies that allow for description and characterization of the microbiome within cattle, their environment, and liver abscesses themselves may help elucidate the etiology of liver abscess formation and allow for targeting interventions that will provide solutions to replace or reduce antimicrobial use that is currently used for the reduction of liver abscess prevalence.

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