Roughage Diet Research Articles

The effects of receiving diet roughage inclusion on performance, health, and serum metabolite characteristics of newly received beef calves.

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 ± 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 ± 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.

Effects of increased dietary roughage during the late finishing period on beef cattle performance, carcass traits, and blood, ruminal, and faecal characteristics

Finishing cattle consume diets high in concentrates to efficiently deposit both muscle and adipose tissue while decreasing cost of gain during finishing. Concerns regarding liver abscesses and late finishing period morbidity and death loss have led to interest in increasing dietary roughage concentrations during late finishing. The objective of the current experiment was to evaluate the effects of increased roughage inclusion late in the finishing period on growth performance, carcass traits, blood, inflammation markers, ruminal, and fecal characteristics of feedlot steers. Crossbred beef steers (n = 60; initial body weight; BW = 289 ± 35.6 kg) were blocked by BW and assigned to experimental dietary treatments in a randomized complete block design during the final 58 d on feed. Experimental treatments included control (CON; 6% roughage DM), intermediate (INT; 12% roughage DM), and high (HGH; 18% roughage DM) roughage diets (CON = 5 pens and INT and HGH = 4 pens; 4 steers per pen). All experimental diets contained dry-rolled corn, prairie hay, Sweet Bran (Cargill, Inc., Blair, NE), dry supplement, urea, and a corn steep and molasses-based liquid supplement. The inclusion rate of roughage and dry-rolled corn were adjusted for each experimental treatment diet. Overall dry matter intake (DMI) tended to increase linearly (P = 0.02) with increasing roughage concentration. No differences in BW, overall average daily gain (ADG), or gain to feed (G:F) were observed (P ≥ 0.72). Rib eye area increased linearly with increasing roughage concentration (P = 0.02). Fat thickness, hot carcass weight (HCW), marbling, liver score, and kidney, pelvic, and heart fat (KPH) did not differ (P ≥ 0.29) among treatments. Steers consuming the HGH diet had a lower fecal pH at the end of the finishing period (P = 0.05) compared to CON and INT steers. Ruminal lactate was increased on d 14 for CON steers compared to other treatments (P < 0.001). No differences were observed for ruminal pH (P ≥ 0.11) among treatments at any collection. Results from the current experiment suggest that increasing roughage late in the finishing period may not negatively impact growth performance or carcass characteristics but does alter feed intake and may alter fermentation and digestion.

Dietary silage supplement modifies fatty acid composition and boar taint in pork fat

Abstract In organic pig husbandry, the use of roughage is mandatory as dietary supplement. This study investigated the effects of oat silage on the fatty acid composition, in entire males and gilts, as well as indole and skatole levels in perirenal adipose tissue of entire males. Entire males and gilts (forty-five to forty-eight pigs/sex) were assigned to two dietary roughage feeds (control with straw vs. oat silage). There was no significant effect of silage or sex on total SFA and MUFA in pork fat. However, the oat silage increased the total PUFA n-3 and decreased the PUFA n-6/n-3 ratio. The content of boar taint compounds (skatole and indole) in the entire male pigs did not differ between diets, although human nose scoring rejected in a greater extent more pork fat from entire males supplemented with oat silage, compared with those only supplied with straw. Approximately 50% of the entire males (90 to 97 kg of carcass) had low skatole values (≤0.1 μg/g), that were below the range of boar taint detection, regardless of the feeding regime. This finding indicates that more studies should be performed to avoid the problem of taint detection in entire males under organic production.

Effects of Different Roughage Diets on Fattening Performance, Meat Quality, Fatty Acid Composition, and Rumen Microbe in Steers.

This study aimed to evaluate different roughages on fatting performance, muscle fatty acids, rumen fermentation and rumen microbes of steers. Seventy-five Simmental crossbred steers were randomly divided into wheat straw group (WG), peanut vine group (PG) and alfalfa hay group (AG), with 5 replicates of 5 steers each. The results showed a highest average daily gain and lowest feed/gain ratio in AG group (P = 0.001). Steers fed alfalfa hay had the highest muscle marbling score and n-3 polyunsaturated fatty acid (PUFA), and also the rumen NH3-N and microbial protein (MCP) concentration among the three groups (P < 0.05). Correlation analysis showed that ruminal NH3-N and MCP were negatively correlated with muscle saturated fatty acid (SFA), while ruminal MCP was positively correlated with muscle PUFA and n-3 PUFA (P < 0.05). 16S rRNA analysis indicated that fed alfalfa hay decreased the abundance of Ruminococcaceae_UCG-001(P = 0.005). More importantly, muscle SFA deposition were positively correlated to the abundance of Ruminococcaceae_UCG-001 (P < 0.05), while the muscle PUFA and n-3 PUFA deposition were negatively correlated to it (P < 0.01). Therefore, alfalfa hay provides a better fattening effect on steers. Alfalfa rich in n-3 PUFA would reduce the abundance of Ruminococcaceae_UCG-001 involved in hydrogenation, increase the rumen protective effect of C18:3 n−3, which is beneficial to the deposition of muscle n-3 PUFA and PUFA.

194 Evaluation of Dietary Roughage Inclusion in a Single or Two-Diet System for Backgrounding and Finishing Steers

Abstract The objective of this experiment was to determine the influence that equal cumulative roughage inclusion in a single diet or two-diet system during a 210-d growing-finishing period has on growth performance responses, efficiency of dietary net energy (NE) utilization, and carcass traits in beef steers. Pre-conditioned beef steers (n = 46; initial shrunk [4%] BW = 281 ± 40.4 kgs) were fed once daily, and bunks were managed according to a slick bunk management system at the Ruminant Nutrition Center in Brookings, SD. Treatments included: 1) A single diet program (targeted a 1.30 Mcal/kg NEg diet fed for 210-d; 1D) or 2) two diet program (targeted a 1.21 Mcal/kg NEg diet fed for 98-d, a 1.30 Mcal/kg NEg diet fed for 14-d, and a 1.39 Mcal/kg NEg diet fed for 98-d; 2D). All steers were implanted on d 1 with a 100 mg trenbolone acetate (TBA) and 14 mg estradiol benzoate (EB) implant and re-implanted with a 200 mg TBA and 28 mg EB implant on d 112. Average daily gain tended (P = 0.06) to be 9.5% greater for 1D compared with 2D during the backgrounding portion and ADG was increased (P = 0.01) for 2D compared with 1D by 11.3% during the finishing phase of the experiment. Cumulative ADG did not differ between treatments (1.61 vs. 1.62 ± 0.046 kgs) for 1D and 2D, respectively. Cumulative observed dietary NEm and NEg did not differ (P ≥ 0.96) between treatments. There were no differences (P ≥ 0.18) detected between treatments for HCW, DP, REA, RF, USDA marbling score, KPH, yield grade, retail yield, EBF, or body weight at 28% estimated EBF. In conclusion, Northern Plains feedlot producers can feed a single growing-finishing diet to preconditioned beef steers with minimal effects on overall growth performance or carcass traits.

204 Effect of Breed Type on Maintenance Energy Requirements and Partial Efficiency of Metabolizable Energy use in Growing/Finishing Cattle

Abstract Consensus is lacking on whether genetic differences exist in the partial efficiency of metabolizable energy use. Genetic differences in net energy required for maintenance have been reported, but independence of body composition was not addressed. The objective was to determine contribution of genetic differences to net energy for maintenance and partial efficiency of metabolizable energy use in growing/finishing cattle independent of body composition. A literature search was performed to compile data (31 studies, 214 treatment means) on metabolizable energy intake (MEI) and composition of empty body gain in growing steers. Dietary roughage concentration and breed were recorded. Data analyses were performed using R statistical package for linear models. For analysis, breeds were categorized as British (Angus, Hereford, English crosses), Continental (Charolais, Simmental, Limousin), Crossbred (British x Continental breeds), Dairy (Holstein), Double-muscled (Belgian Blue, Piedmontese), and Heat-tolerant (Boran, Brahman, Tuli). The base regression model of log10 of heat production on MEI had R2 of 0.8830 and intercept of 1.912 (81.6 kcal/kg.75). Inclusion of breed type significantly (P &amp;lt; 0.0001) affected the intercept and slope of the model. Dietary roughage concentration, empty body fat percentage, and energy retained as protein or fat, but not empty body protein percentage, explained a significant amount of variation (P &amp;lt; 0.01) resulting in R2 of 0.9851. In this final model, Heat-tolerant breeds had 12% lesser (P &amp;lt; 0.05) net energy for maintenance than British with Continental, Crossbred, and Double-muscle being intermediate, and Dairy had 27% greater (P &amp;lt; 0.05) net energy for maintenance than other breed types. Also, breed type by MEI interaction was significant (P &amp;lt; 0.0001) with Dairy having lesser (P &amp;lt; 0.05) slope than other breeds, and Heat-tolerant having greater slope than British. In conclusion, breed type affected net energy for maintenance and partial efficiency of metabolizable energy use after accounting for body composition and dietary roughage concentration suggesting that genetic variation exists.

Impacts of added roughage on growth performance, digestibility, ruminal fermentation, and ruminal pH of feedlot steers fed wheat-based feedlot diets containing 30% modified distillers grains with solubles.

Two experiments were conducted to evaluate the inclusion rate roughage in wheat-based diets containing modified distillers grains with solubles (MDGS) on feedlot performance (Feedlot Experiment), as well as digestibility, ruminal pH, and ruminal fermentation characteristics (Digestibility Experiment). The feedlot experiment utilized 72 Angus steers (392 ± 46.3 kg initial body weight) which were randomly assigned to 1 of 12 pens, 3 pens per treatment, to evaluate feedlot performance and carcass characteristics. Dietary treatments were 1) control; 10% roughage, 2) 12% roughage, 3) 14% roughage, and 4) 16% roughage. The digestibility experiment used four ruminally and duodenally cannulated steers (393 ± 33.0 kg) in a 4 × 4 Latin Square with either 10%, 12%, 14%, or 16% roughage as in the feedlot experiment. However, dietary roughage source was different between these two experiments and included a combination of grass hay and wheat straw (Feedlot Experiment), and corn silage (Digestibility Experiment). All data were analyzed with the Mixed Procedures of SAS. Feed intake was recorded, with duodenal and fecal output calculated using chromic oxide. Ruminal pH and fermentation were assessed. Growth performance and most carcass characteristics were not affected by increasing roughage (P ≥ 0.11). Marbling tended to decrease linearly (P = 0.10) with increasing roughage inclusion. Increasing dietary roughage content had no effect on organic matter intake (P = 0.60) in the digestibility experiment. Intake, duodenal flow, and digestibility of neutral detergent fiber and acid detergent fiber were not affected by treatment (P ≥ 0.16). Ruminal pH increased linearly (P < 0.01) as rate of roughage inclusion increased. Ruminal concentrations of acetate and butyrate increased, and propionate decreased in a linear fashion (P < 0.01) thereby increasing (P < 0.01) acetate and butyrate to propionate ratio with increasing dietary roughage. Our data indicate that increasing roughage inclusion in wheat-based diets including 30% MDGS increased ruminal pH and shifted ruminal fermentation patterns. Additionally, increasing roughage inclusion did not affect feedlot performance in steers fed wheat at 36% to 42% of dietary dry matter in combination with 30% MDGS.

Microbiome network traits in the rumen predict average daily gain in beef cattle under different backgrounding systems

BackgroundBackgrounding (BKG), the stage between weaning and finishing, significantly impacts feedlot performance in beef cattle; however, the contributions of the rumen microbiome to this growth stage remain unexplored. A longitudinal study was designed to assess how BKG affects rumen bacterial communities and average daily gain (ADG) in beef cattle. At weaning, 38 calves were randomly assigned to three BKG systems for 55 days (d): a high roughage diet within a dry lot (DL, n = 13); annual cover crop within a strip plot (CC, n = 13); and perennial pasture vegetation within rotational paddocks (PP, n = 12), as before weaning. After BKG, all calves were placed in a feedlot for 142 d and finished with a high energy ration. Calves were weighed periodically from weaning to finishing to determine ADG. Rumen bacterial communities were profiled by collecting fluid samples via oral probe and sequencing the V4 region of the 16S rRNA bacterial gene, at weaning, during BKG and finishing.ResultsRumen bacterial communities diverged drastically among calves once they were placed in each BKG system, including sharp decreases in alpha diversity for CC and DL calves only (P < 0.001). During BKG, DL calves showed a substantial increase of Proteobacteria (Succinivibrionaceae family) (P < 0.001), which also corresponded with greater ADG (P < 0.05). At the finishing stage, Proteobacteria bloomed for all calves, with no previous alpha or beta diversity differences being retained between groups. However, at finishing, PP calves showed a compensatory ADG, particularly greater than that in calves coming from DL BKG (P = 0.02). Microbiome network traits such as lower average shortest path length, and increased neighbor connectivity, degree, number and strength of bacterial interactions between rumen bacteria better predicted ADG during BKG and finishing than variation in specific taxonomic profiles.ConclusionsBacterial co-abundance interactions, as measured by network theory approaches, better predicted growth performance in beef cattle during BKG and finishing, than the abundance of specific taxa. These findings underscore the importance of early post weaning stages as potential targets for feeding interventions that can enhance metabolic interactions between rumen bacteria, to increase productive performance in beef cattle.

Effects of dietary concentrate: forage ratio on development of gastrointestinal tract in black Tibetan sheep

ABSTRACT This study aims to evaluate the effects of dietary concentrate: forage ratio (C:F) on the development of the gastrointestinal tract in Tibetan lamb. A total of 60 healthy two-month-old weaned black Tibetan sheep (approximately 10.50 kg of initial body weight) were assigned to three treatments and fed C:F of 70:30 (HC group), 50:50 (MC group) and 30:70 (LC group). Using the haematoxylin-eosin (HE) staining, morphological results showed that the increase of dietary roughage level from 30 to 70% exerts a positive effect on the development of the forestomach including rumen, reticulum and omasum, especially in papillae and muscle layer. Both submucosa thickness and muscle layer of abomasum are significantly increased in the LC group when compared with the HC group. Moreover, the mucosal thickness of the small intestine is higher in the LC group than that in the HC group, whereas crypt depth is higher in HC compared to the LC group. These data suggest that increased dietary forage levels promote gastrointestinal tract growth in black Tibetan sheep by changing in papilla, muscle layer and mucosal thickness, and concentrate can be supplemented up to 30% to fulfil the nutrient requirements without restriction on the development of the gastrointestinal tract.

Breed and diet influence the ruminal bacterial community of sheep

Context Ruminal microbial communities are important in production ruminants, as they can affect health and production efficiency. Differences between meat- and wool-producing sheep breeds have not yet been fully explored. Aims In this study, we aimed to determine the impact of diet on ruminal microbial populations of sheep selected for different production traits, namely, meat production (White Suffolk) and wool production, and quality (Poll Merino). Methods The study utilised 24 White Suffolk and 24 Poll Merino ewes, assigned to either a roughage (20% pellet and 80% chaff) or high-grain diet (80% pellet and 20% chaff). Following acclimatisation for 21 days, they each had a ruminal sample taken and analysed for bacterial communities, using 16S rRNA sequencing. Entry and exit weight of the ewes and their feed intake were measured. Key results There was a preference for the high-grain diet (P &lt; 0.0001), with greater amounts consumed, although there was no significant difference in ewe weights between the two dietary treatments. However, White Suffolk ewes lost weight on the roughage diet, whereas all other groups gained weight (White Suffolk roughage −5.9 ± 2.6 kg, White Suffolk high-grain 7.8 ± 1.7 kg, Poll Merino roughage 9.2 ± 2.7 kg, Poll Merino high-grain 5.0 ± 1.8 kg). There were significant ruminal bacterial differences associated with both diet and breed. The average dissimilarity in ruminal bacterial phyla associated with diet was 14.13%, with the top 50% of phyla contributing to the dissimilarity being Verrucomicrobia, Lentisphaerae, Elusimicrobia, SR1 and Fibrobacteres, which were significantly more abundant in the roughage dietary group, and Proteobacteria, which were significantly more abundant in the high-grain dietary group. Conclusions We have demonstrated that although diet strongly influences the ruminal microbiota, there is a significant interaction between diet and breed in effects on ruminal microbiota and also animal performance. Implications The differences in microbial composition between breeds were related to some of the animal productivity differences of the two breeds, indicating that at least some of the genetic differences in animal productivity are generated by differences in the responsiveness of the ruminal microbiota to diet.

Effect of protein and glucogenic precursor supplementation on forage digestibility, serum metabolites, energy utilization, and rumen parameters in sheep

Supplementation of glucogenic precursors in roughage diets may increase production responses due to improved efficiencies of nutrient utilization. Therefore, the objective of this study was to determine the effect of source of supplemental glucogenic potential (GP) on forage digestibility, serum metabolites, energy utilization, and rumen parameters of growing wethers consuming a roughage diet (8.8% crude protein, 71.4% ash-free neutral detergent fiber). Crossbred wethers (49.1 ± 4.7 kg initial BW; n = 16) were utilized in a 4 × 4 replicated Latin Square design with four periods of 21 d. Supplements were designed to supplement increasing amount of GP: 1) no supplementation (CON; 0 g), 2) 40 g of calcium propionate (CAP; 30 g of GP), 3) 70 g of blood meal + 100 g of feather meal (BF; 40 g of GP), or 4) combination of CAP and BF (COMBO; 70 g of GP). Total fecal and urine collection was conducted from days 13–17 to calculate digestibility estimates and urinary losses. An acetate tolerance test was administered on day 17 to determine the effect of GP on acetate clearance. Blood samples were collected on day 19 and were analyzed for serum concentrations of glucose, urea N (SUN), non-esterified fatty acids, and amino acids. Rumen fluid was collected on day 21 to determine supplementation effects on ruminal volatile fatty acid (VFA) and ammonia concentrations. Wethers receiving BF and COMBO supplementation had greatest (P ≤ 0.01) DM and OM total tract digestibility. Supplementation did not affect (P ≥ 0.37) NDF digestibility or digestible energy. Urinary nitrogen excretion was greatest (P = 0.02) for BF and COMBO. Circulating serum essential amino acid concentration was increased (P < 0.01) in BF and COMBO compared to CAP and CON. In addition, BF and COMBO had increased (P < 0.01) SUN concentrations compared to CAP and CON. Acetate half-life was not affected (P = 0.39) by supplementation strategy. However, area under the curve (AUC) for acetate was decreased (P = 0.04) with supplementation of BF and COMBO compared to CON-fed wethers. Ruminal propionate concentration was increased (P ≤ 0.01) for wethers fed CAP and COMBO supplementation, which resulted in decreased (P ≤ 0.01) A:P ratio. Overall, these results indicate that the increased propionate supply by providing propionate salts did not result in a protein sparing impact or increased N retention.

Dietary treatment with omega fatty acids mediates in vitro rumen fermentation kinetics and reduce methane emission in water buffalo

Purpose: To investigate the effect of dietary supplementation of two omega fatty acids on in vitro rumen fermentation, microbial populations, total gas and methane (CH4) production．Methods: Both linoleic and linolenic acids were supplemented at 0 (control), 1, 3, 5 and 7 % of dry matter (DM) in a ration with a high roughage to concentrate ratio (70: 30). Total gas and CH4 were measured at 3, 6, 9, 12 and 24 h of fermentation while pH, volatile fatty acids (VFA), and ammonia nitrogen (NH3-N) concentrations were measured at 24 h using buffalo rumen fluid in an in vitro batch culture system. Microbial populations were determined using 16S-rDNA gene primers by RT-PCR.Results: The results revealed that linoleic acid at 3, 5 and 7 % decreased the concentration of NH3-N (p&lt; 0.05) but linolenic acid at 5 and 7 % increased NH3-N (p &lt; 0.05). A linear decrease (p &lt;0.001) in acetate and butyrate, coupled with linear increase (p &lt;0.001) in propionate was observed in response to treatment. Furthermore, supplementation of 3, 5 and 7 % of both fatty acids linearly (p &lt; 0.001) decreased total gas and CH4 production when compared to the control. The addition of linoleic acid linearly (p &lt; 0.001) decreased the number of protozoa without affecting methanogens, while linolenic acid linearly and quadratically (p &lt; 0.001) reduced the population of both protozoa and methanogens (p &lt; 0.05).Conclusion: Linolenic acid is more effective at a 3 % level in reducing methane production (up to 63 %) in high roughage diets.

PSVII-15 Effects of electrolyzed reduced water on intake, digestion and ruminal fermentation parameters in beef cattle

Abstract The effect of electrolyzed reduced water consumption by cattle is not well defined. The objective of this study was to evaluate the effect of electrolyzed reduced water on intake, in vitro true digestibility (IVTD), ORP and pH in four ruminally cannulated steers (4 Bos taurus; 317 kg BW). Steers were subjected to a two period (14 d), two treatment crossover design. Treatment included: 1) standard water (CON; pH = 7.0 ± 1.0) or 2) electrolyzed reduced water (ERW; pH = 9.0 ± 1.0). The project comprised of two studies where the effects of ERW were observed for steers consuming a roughage diet (phase 1) or concentrate diet (phase 2). During Phase 1, animals were provided bermudagrass hay ad libitum. A 14 d transition period followed phase 1 to allow transition of diets. In phase 2, animals were maintained on a concentrate diet. During each period, d 1–8 served as a treatment adaptation phase, d 9–13 allowed for measures of intake and digestion, and rumen fluid was collected at h 0, 2, 4, 8, and 12 after feeding on d 14 for VFA, pH and ORP analysis. Data were analyzed using the MIXED procedure of SAS 9.4 (SAS Inst. Inc., Cary, NC). Intake, digestion, and ruminal fermentation parameters were not different for CON vs ERW steers (P ≥ 0.06). Analysis of VFA data have not been finalized and will be reported later. Results indicate that ERW has no effect on intake, digestion or ruminal fermentation parameters of steers consuming roughage or concentrate diets.

PSX-A-22 Late-Breaking: Rumen microbiome composition and microbe network dynamics in beef cattle predict finishing performance under different backgrounding systems

Abstract Backgrounding (BKG) impacts growth and finishing performance in beef cattle. However, specific microbiome contributions to growth performance during this period, considering different BKG systems, remain unknown. A longitudinal study was designed to characterize the rumen microbiome and average daily gain (ADG) of Angus and Angus x Simmental calves (n = 38) placed under different BKG systems for 55 d after weaning: DL: a high roughage diet within a dry lot and CC: annual cover crop within a strip and PP, while a third group, PP: remained on perennial pasture vegetation within rotational paddocks, just as before weaning. After BKG, calves went to a feedlot for 142 d and finished with a high energy ration. Rumen bacterial communities were profiled by collecting fluid samples via oral probe, and sequencing the V4 region of the 16S rRNA bacterial gene, at weaning, during backgrounding and finishing. For calves moved to CC and DL BKG, bacterial composition diverged drastically, including sharp decreases in bacterial diversity (P &amp;lt; 0.001), while PP claves conserved more stable diversity patterns. During BKG, DL calves also showed the greatest ADG (P &amp;lt; 0.05), which coincided with increased abundance of taxa affiliated to the Aeromondales (Succinivibrio, Succcinimonas and Ruminobacter) (P &amp;lt; 0.001). However, once in the finishing phase, PP calves showed compensatory ADG, with significantly higher values, particularly compared with calves on DL BKG (v = 0.02). Network theory analyses were concordant with these patterns, highlighting the importance of understanding microbe-microbe interactions at early developmental stages to predict finishing performance. These results indicate that rumen microbes and their network interactions during backgrounding successfully predict finishing performance in beef cattle, underscoring the importance of early post weaning stages as potential targets for feeding interventions that can modulate the rumen microbiome to enhance lifelong animal performance.

308 Effects of Roughage Source on Growth Performance, Carcass Characteristics, and Rumination Time of Beef Steers Fed Steam-flaked Corn Finishing Diets

Abstract We hypothesized that roughage source would not impact rumination time and growth performance if the different sources provided a similar concentration of dietary neutral detergent fiber (NDF) and physically effective NDF (peNDF). This experiment’s objective was to evaluate rumination time, and growth performance steers consuming finishing diets with differing roughage sources (corn stalks, cotton burrs, or wheat silage). Beef steers (n = 49; BW = 317 + 5.6 kg) were used in a completely randomized design with 3 dietary treatments. Steers consumed a steam-flaked corn-based diet containing corn stalks (CS), cotton burrs (CB), or wheat silage (WS) included at 7% (DM basis). Dietary NDF was similar (P = 0.36) across treatments. Each steer was fitted with a sensory collar to record daily rumination. Weekly ingredient and dietary samples were estimated for physically effective NDF (epeNDF) using the Penn State Particle Separator. Actual physically effective NDF (apeNDF) was calculated based upon rumination time. Neither initial nor final body weight (BW) differed between treatments (P &amp;gt; 0.52); nor did average daily gain (ADG), dry matter intake or carcass adjusted variables of FBW, ADG, empty BW, or empty body fat (P &amp;gt; 0.31). However, gain to feed (G:F) tended to differ (P = 0.06) between treatments. The CS diet had the greatest G:F with no difference (P = 0.75) between CB and WS. Dietary NDF and epeNDF were similar (P &amp;gt; 0.35) among roughage sources; however, CB had the least apeNDF, consistent with lower rumination time (P &amp;lt; 0.01). When energy values were calculated from animal performance, the CS diet had the greatest observed energy values, followed by WS and CB having the least. These results indicate roughage source impacted rumination time, although steers were fed a steam-flaked corn-based finishing diet with similar dietary roughage and NDF inclusions.

A survey of producer practices and reproductive performance of containment and supplementary fed ewes.

Containment feeding, where ewes are fed complete rations, is used to maintain flock numbers in periods of inadequate pasture supply. Producer practices influence both the reproductive performance of ewes and the risk of health challenges. The aim of this study was to evaluate the reproductive, feeding and health management practices of producers using containment or supplementary feeding, and quantify any associations between practice and reproductive performance. An online survey of Australian producers was conducted in 2020. The number of responses (n=43) allowed benchmarking but was insufficient to determine correlations between practice and performance. The reported pregnancy rate of adult Merino ewes was variable between respondents (78%-95%; n=11), and lambs marked per ewe joined ranged from 60% to 110% (n=9). In non-Merino flocks, lambs marked ranged from 82% to 161% (n=4). Most respondents (9/11) fed cereal grain with hay or straw, either daily or two or three times a week. However, some respondents fed grain only or roughage only, such that the percentage of roughage in diets ranged from 0% to 100%. Ewes were most frequently separated into age groups for feeding, and shy feeders were only removed by 25% of respondents. Although generally the reported reproductive rate was high, wide variation indicates potential for improvement. Best practice management for containment remains unclear and requires further research given the diverse practices used. Veterinary practitioners should be aware that some of the practices used may contribute to reduced productivity or health issues in ewes.

Effects of corn stalk inclusion and tylosin on performance, rumination, ruminal papillae morphology, and gut pathogens associated with liver abscesses from finishing beef steers

To reduce prevalence of liver abscesses in finishing beef steers, we must evaluate the possibility of pathogens originating from the hind gut as well as the rumen. We hypothesized that pathogens promoting liver abscess formation are located throughout the gut, and increased dietary roughage levels could improve gut integrity over time. Two hundred sixty-three crossbred beef steers (BW = 258 ± 29 kg) were used in a randomized complete block design with 7-8 hd/pen (8 pens/treatment) using a 2 × 2 factorial treatment structure. Steers received steam-flaked corn-based diets with 5 or 15% corn stalk (CS) inclusion (dry matter basis, DMB) and with (TYL) or without (NTYL) tylosin (7.9 g/T; DMB). Half of the pens in each treatment remained on feed for the entire experiment duration (Exp 1) whereas the remaining half were designated for serial slaughter (Exp 2). Steers were fed each day at 0700 h for an average of 220 d (heavy block = 175 d, light block = 233 d). For Exp 2, eight steers were slaughtered on d 0 to obtain initial tissue samples and thereafter one pen/treatment was slaughtered every 56 d. During serial slaughter, dorsal and ventral sac rumen tissue samples were collected for histopathological evaluation along with ruminal, ileal, and colonic tissues for bacterial isolation. Data were analyzed using mixed models; pen was the experimental unit for performance outcomes and individual animal was the experimental unit for bacterial isolation and histopathological data. No interaction (P ≥ 0.40) between tylosin and CS inclusion was detected for ADG or final BW. Interactions were detected for DMI and G:F; both outcomes were similar when tylosin was included in the diet, however both outcomes differed notably without tylosin. Perimeter and length of ventral rumen papillae decreased (P ≤ 0.01) as DOF increased. In contrast, dorsal rumen papillae perimeter and length increased through d112 and then decreased through d231. Corn stalk inclusion rate did not affect the incidence of bacterial species isolated from the ruminal (P = 0.38), ileal (P > 0.15), or colonic (P > 0.37) epithelial tissues. Cattle consuming the TYL diets tended to have decreased (P = 0.06) presence of ileal Fusobacterium necrophorum subsp. necorphorum and increased (P = 0.07) rates of ruminal Salmonella enterica compared to NTYL. Prolonged consumption of a finishing diet, regardless of CS or TYL inclusion, seemed to be the major source of change in rumen epithelial tissue morphology.

Characteristics of carcass and non-carcass components of lambs fed wet brewery waste as a roughage feed

The objective of the present study was to evaluate the effect of including wet brewery waste (WBW) as the exclusive dietary roughage source on the characteristics of carcass and non-carcass components of feedlot-finished lambs. Thirty-two non-castrated male lambs weaned at 50 days of age, resulting from the cross between the Texel and Ile de France breeds, were used. The diet was constituted by roughage (WBW) and a concentrate composed of crushed maize, soybean meal, limestone and common salt. Treatments consisted of four levels of WBW as the roughage source in the diet (% dry matter), namely, 31, 44, 57 and 70%. Lambs were slaughtered upon reaching 34 kg live weight. The treatments resulted in a linear decrease in hot and cold carcass weights and yields, carcass compactness index, conformation, degree of fatness and rib-eye area. Among the primal cuts, the absolute weights of pallet, ribs and legs decreased as the WBW level was increased. As to the non-carcass components, only the total gastrointestinal content increased linearly with WBW. The increasing levels of WBW led to greater fasting losses and reduced carcass weights and yields. There was also a reduction in the degree of fatness, carcass compactness, carcass conformation index and rib-eye area Wet brewery waste at the concentration of 31% as the roughage source in the diet of finishing lambs in the feedlot provides better carcass traits.

Performance, carcass traits and meat quality of lambs fed with different roughage: concentrate ratios associated with variable physically effective neutral detergent fibre content

AbstractThis study evaluated the effect of roughage:concentrate (R:C) ratio associated with a variable particle size of physically effective neutral detergent fibre (peNDF8) in the forage (Tifton-85 hay) on the performance, carcass traits and meat quality of lambs. Seventy-two 4-month-old, non-castrated Santa Ines male lambs (23.5 ± 2.32 kg BW) were distributed in a completely randomized design, in a 2 × 2 factorial arrangement [two peNDF8 hay particle sizes (13 and 6 mm) and two R:C ratios (700:300 and 500:500 g/kg DM total)]. DMI, DM, NFC and TDN digestibility's, N-intake and N-faecal excretion were affected by the R:C ratio (P &lt; 0.05). However, the N-retained was not affected by the studied variables (P &gt; 0.05). It was observed an interaction (P &lt; 0.05) between the peNDF8 and R:C ratios for final BW, average daily gain (ADG), colour parameters and pH 24 h. The lower roughage ratio provided greater (P &lt; 0.05) concentrations of C14:1, C16:1–cis9, C18:1–cis9, ΣMUFA, Σn–6:Σn–3 and hypocholesterolemic/hypercholesterolemic index, enzymatic activity Δ9desaturase-C16 and -C18. Lambs fed a lower roughage diet had improved performance and feed efficiency, however, presented reduced polyunsaturated fatty acids (PUFA) concentrations in the meat, especially Σn–3 family. Higher roughage diet and larger peNDF8 particle size improved the concentrations of PUFA while decreased Σn–6:Σn–3 ratio in meat. Larger peNDF8 particle size associated with higher roughage proportion, have reduced animal performance however, it increased protein concentration, a* and C* colour parameter without affecting fatty acids profile of Longissimus lumborum muscle.

Effects of different banana crop wastes on nutrient intake and digestibility, microbial protein synthesis, feeding behavior, and animal performance of ¾ Holstein × Zebu heifers in a semiarid rangeland.

The objective of this study was to evaluate the use of banana crop wastes in diets of ¾ Holstein × ¼ Zebu heifers on the intake and digestibility of nutrients, microbial protein synthesis, feeding behavior, and animal performance. Eight ¾ Holstein × ¼ Zebu heifers were utilized with an average age of 18 ± 1.0 months and an average body weight (BW) of 298 ± 3.06 kg. The experiment was distributed in two simultaneous 4 × 4 Latin squares. The treatments were as follows: Diet 1 (SS)-sorghum silage as exclusive dietary roughage; diet 2 (SSL)-sorghum silage (50%) associated with 50% leaf hay of banana trees (on a DM basis); diet 3 (SSBP)-sorghum silage (50%) associated with 50% banana peel hay; and diet 4 (SSPS)-sorghum silage (50%) associated with 50% pseudostem hay of banana trees. The roughage:concentrate ratio was 75:25. The greatest dry matter intake (DMI; p < 0.01) was found in heifers that received the SS and SSBP diet, mean of 10.19 kg/day. The SS diet showed greatest dry matter digestibility (DMD; p < 0.01) and crude protein digestibility (CPD; p < 0.01). The concentration of total purines (p < 0.01) and absorbed purines (p < 0.01), microbial protein synthesis (p < 0.01), and microbial efficiency (p < 0.01) was higher in the SSBP diet in comparison with SS and SSL diets. The longest eating time was observed in animals that received the SSL diet, being 17.79% higher (p = 0.01) than the SSBP diet. The final BW (p = 0.39) and BW gain (p = 0.39) were similar, with averages of 319.84 kg and 1.08 kg/day, respectively. Biometric measurements were not altered as a function of bedtime (p > 0.05). Banana wastes can be used to feed ¾ Holstein × ¼ Zebu heifers in partial replacement for sorghum silage as they do not alter the animals' weight gain and body development.