Total Mixed Ration Research Articles

57 Effect of diet mixing strategies on growth performance and carcass characteristic in feedlot steer

Abstract Our objective was to determine the effects of a feeding management strategy on growth and carcass quality and characteristics on finishing feedlot beef cattle. Angus-Simmental steers (n = 60), blocked by body weight (BW), were housed in individual pens and randomly assigned to treatments. Treatments were total mixed ration (TMR) or a non-mixed diet (Split). The diet contained 67.5% of dry rolled corn, 18% of distiller grains with soluble, 2.5% soybean meal, 7% hay, and 5% of mineral and vitamin mixed. The diet composition for both treatments was similar, the only difference was the use of a TMR or that the concentrate was fed separately from the hay on the Split treated calves. Feed intake was monitored through slick bunk management in both treatments. For the Split assigned calves, if any hay or concentrate was left in the bunk on two consecutive days, the total feed was decreased by 5%; maintaining always the 93% concentrate and 7% forage ratio. Steers were weighed monthly and feed samples were collected for nutrient composition analysis semimonthly. Monthly weights and intakes were used to calculate average daily gain (ADG) and gain to feed ratio (G:F). Steers were slaughtered per block when the average weight of the block reached 555 kg. Carcasses were evaluated 48 h post slaughter. Carcass yield and quality factors were evaluated at the 12th/13th rib interface. Data were analyzed as randomized complete block design. Considering the fixed effect of the feeding strategy and the random effect of block. We did not observe differences (P > 0.17) in growth performance or carcass characteristics variables due to management strategy (Table 1). The lack of observed differences due to treatment might be because the ratio of concentrate and forage intake was similar for both groups, in addition to the slick bunk management in both treatments, which forced steers to eat all their ration, independent of the treatment, to continue to receive the same amount of feed.

104 Effects of providing vitamin and mineral supplementation throughout gestation on subsequent F1 replacement heifer liver and muscle oxygen consumption and mitochondrial function throughout pregnancy

Abstract The study aimed to assess the impact of maternal vitamin/mineral supplementation during gestation on the energy utilization in liver and muscle tissues of F1 heifer offspring. We hypothesized that VTM supplementation during gestation would mitigate mitochondrial energy loss and uncoupling of liver and muscle tissue in pregnant offspring. At breeding, crossbred Angus heifers [n = 31; initial body weight (BW) = 412.5 ± 53.68 kg] were randomly assigned to either a basal diet targeting BW gains of 0.45 kg•heifer-1•d-1(CON; n = 14) or the basal diet plus 113 g•heifer-1•d-1of a vitamin/mineral supplement (VTM; n = 17). Heifers remained on their respective dietary treatments until calving. After calving, all F1 heifer calves were raised in a single management group with their dams until weaning (BW = 209 ± 4.82 kg; VTM, n = 17; CON, n = 12) and fed a common diet throughout postnatal development. At breeding and throughout gestation, F1 heifers (n = 9, VTM; n = 7, CON) were allotted daily feed intakes of 1.5% of BW on a dry-matter basis as a total mixed ration and used to evaluate cellular energy metabolism throughout pregnancy. Liver and Longissimus dorsi muscle biopsies were collected on d 179 and d 247 +/- 3 of gestation and mitochondrial function was assessed via high resolution respirometry (Oroboros Instruments, Innsbruck, Austria). The following respiratory states were evaluated: LEAK respiration (L), OXPHOS capacity (P), NADH-linked OXPHOS (PI), and electron transfer capacity (E). Data were analyzed using the MIXED procedure of SAS with repeated measures where appropriate. No treatment × trimester interaction (P ≥ 0.13) was observed for any of the respiratory states in liver and muscle. Hepatic oxygen consumption was not influenced by maternal gestational VTM supplementation (P ≥ 0.68), or stage of gestation (P ≥ 0.27). In muscle, L respiration was the only state affected by maternal dietary treatments, being greater (P = 0.05) in CON than VTM heifers. Additionally, L respiration was greater (P = 0.02) during the third trimester compared with the second trimester. This observation in CON heifers is important because increased L respiration (proton leak) results in decreased ATP production. Protons that escape the intermembrane space, are dissipated as heat rather than be used for ATP synthesis; thus, oxygen consumption increases to compensate for the reduction of protons entering ATP turnover. Results show increased muscle mitochondria inefficiency in offspring with dams lacking supplementation during pregnancy. The increased incidence of proton leak results in potentially less efficient cattle as protons escape the electron transport chain rather than be transformed for energy utilization need of the animal, thus VTM supplementation throughout pregnancy impacts fetal development with potential effects in live offspring 18 to 22 mo post-parturition.

PSIV-A-12 Ruminal in vitro digestibility of novel pennycress meal using the Daisy II incubator

Abstract Field pennycress seed has a high oil content, making it valuable for biofuel production. The high protein content of the resulting pennycress meal makes it a potentially valuable protein feedstuff for livestock. However, pennycress meal also contains greater content of fiber, erucic acid, and glucosinolates, which limit its use in livestock rations. Golden pennycress, a novel pennycress, was developed to contain greater oil content and decreased content of fiber, increasing the value of pennycress meal as a potential livestock feed. The objective of this research was to characterize a novel pennycress meal using an in vitro rumen fermentation system. Digestion of golden pennycress (GPC), black-seeded pennycress (BPC), and a total mixed ration (TMR, as the control), was evaluated in vitro using the Daisy II incubator. Each incubation vessel contained 12 filter bags (4 containing GPC, 4 containing BPC, and 4 containing the TMR). Rumen fluid was collected from two cannulated steers and processed according to Ankom procedures; samples were incubated in the rumen fluid inoculum for either 24 or 48 h. Neutral Detergent Fiber (NDF) of GPC averaged 23% (dry matter basis) and was less than the BCP NDF content (30%, dry matter basis). In vitro true dry matter disappearance (IVTDMD) and in vitro neutral detergent fiber digestibility (NDFD) were calculated and shown in Table 1. Proc Mixed procedures of SAS were used to identify difference in digestibility. Due to the novelty of golden pennycress, this study appears to be the first that compares ruminal digestibility of pennycress meals, thereby establishing initial data relative to the feeding value of GPC. As the novel pennycress was developed to have a reduced fiber level, the reduced NDF content of GPC over BPC was expected. The significant increase of IVTDMD of GPC compared with BPC at either incubation length suggests increased overall digestibility and improved dry matter utilization of the novel pennycress. Additional research investigating the reduced NDFD of GPC is warranted. As the first study evaluating the use of golden pennycress meal in ruminant diets, this study provides baseline values from which to build additional research projects.

PSV-10 Evaluation of the effect of probiotic feed additives in the diet to improve dairy production and quality measures

Abstract There is limited information regarding the effectiveness of probiotic feed additives in the diet of lactating dairy cows. This study aimed to determine the effect that Fastrack probiotic had on the yield and milk quality measures of lactating dairy cows. To accomplish this goal, lactating Holstein cows (n = 80) were equally divided into two treatment groups: one supplemented with a probiotic (PRO) and one that did not receive the probiotic supplement (CON). The cows remained in their treatment groups for the duration of the 120-d study and were given ad libitum access to a total mixed ration consisting of 35% corn silage, 30% rolled corn, 10.5% soybean meal, 23% DDGS, and 1.5% mineral supplement. Cows on the PRO treatment were given 1 kg of DDGS once a day at milking that had the probiotic mixed in while the CON treatment were given 1 kg of the same DDGS that did not have the probiotic included. Preliminary results of this study show a decrease in individual treatment records for cows on the PRO treatment and an increase of 2 kg of milk yield per day.

Effect of commercial fibrolytic enzymes application to normal- and slightly lower energy diets on lactational performance, digestibility and plasma nutrients in high-producing dairy cows.

The inclusion of fibrolytic enzymes in the diet is believed to have positive effects on animal production. Hence, the objective of this study was to investigate the impact of supplementing diets with a commercial fibrolytic enzyme preparation (Vistamax; mixture of xylanase and cellulase) derived from Trichoderma reesei on lactational performance, digestibility, and plasma nutrient levels in high-producing dairy cows. Two dietary energy levels were considered: a normal energy diet (metabolizable energy = 2.68 Mcal/kg) and a slightly lower energy diet (metabolizable energy = 2.55 Mcal/kg). A total of 120 lactating Holstein cows (parity = 2; Days in Milk = 113 ± 23) were randomly assigned to four treatment groups using a 2 * 2 factorial arrangement. The dietary treatments consisted of: (1) normal energy diet without enzyme supplementation (NL); (2) normal energy diet with enzyme supplementation (NLE); (3) slightly lower energy diet without enzyme supplementation (SL); and (4) slightly lower energy diet with enzyme supplementation (SLE). The amount of enzyme added to the diets was determined based on previous in vitro studies and supplier recommendations. The enzyme and premix were mixed prior to the preparation of the total mixed ration, and the trial lasted for a duration of 42 days. The results indicated that the application of the fibrolytic enzyme did not have a significant effect on dry matter intake (DMI), but it did enhance the digestibility of dry matter (DM), neutral detergent fiber (NDF), potentially digestible NDF (pdNDF), organic matter (OM), milk production, milk urea nitrogen (MUN), and blood urea nitrogen (BUN). On the other hand, the slightly lower energy diet resulted in a decrease in DMI, milk production, milk protein yield, plasma free amino acids (FAA), and an increase in plasma B-hydroxybutyrate (BHBA). In conclusion, the inclusion of the fibrolytic enzyme in the diets of dairy cows led to improvements in the digestibility of DM, NDF, pdNDF, OM, milk production, and feed efficiency. Furthermore, the application of the enzyme to the slightly lower energy diet resulted in milk production levels comparable to those observed in cows fed the untreated normal energy diet.

Nutrient utilization, growth performance, and antioxidative status of Barki lambs fed diets supplemented with black (Nigella sativa) and rocket (Eruca sativa) seeds

The current study aimed to determine the polyphenol compounds in Nigella sativa (NS) and Eruca sativa (ES) seeds, and evaluate the impact of their addition either as a sole additive or in combination on the growth performance, digestibility, some rumen and blood parameters and antioxidative status of Barki lambs. Forty-eight male lambs (27.18 ± 0.22 kg, 5–6 months), were divided into 4 balanced groups. The experimental diets were randomly distributed to the control group (CON); fed alfalfa hay plus concentrate feed mixture at a ratio of 30:70% without additives, while, NSD, ESD, and NESD groups: fed CON diet plus 2% NS, 2% ES or 1% NS + 1% ES, respectively as a ratio from total mixed ration (TMR). Results indicated that rutin and catechin were the most phenolic compounds observed either in NS or ES seeds. The NS and ES-supplemented groups recorded the highest (P < 0.05) values for dry matter digestibility, nutritive values, average daily gain, and the best feed conversion ratio. However, growth performance, nutritive value, and all nutrient digestibility except for dry matter were not significantly altered with the NESD group. Concentrations of ruminal NH3-N and TVFA were significantly (P < 0.05) reduced with the NESD group, with no significant differences in pH values among different groups. Values of blood parameters showed significant increases in WBCs, PCV, and T-AOC, and decreases in cholesterol, triglycerides, and MDA with the addition of NS and ES seeds or both. Therefore, the addition of NS and ES seeds is recommended to improve lambs’ health and antioxidant status.

Feeding pomegranate pulp to Ghezel lambs for enhanced productivity and meat quality

Agrifood by-products contain nutrients and bioactive compounds that can be used in the diets of livestock – thereby value-adding to an otherwise waste product of environmental and economic significance. This study investigated the effect of dietary pomegranate pulp in the total mixed ration of Ghezel lambs, evaluating its effect on growth performance, blood parameters, carcass traits, as well as meat quality and shelf life. 3-month-old Ghezel lambs (individually housed, n = 8) were randomly assigned to be either non-supplemented (control) or supplemented with 100 g/kg DM of sun-dried pomegranate pulp for 28 days, post-adjustment. Results showed that supplementation of lamb diets with pomegranate pulp significantly increased liveweight and average daily gains, while not significantly affecting dry matter intake. Lamb serum urea and alkaline phosphatase concentrations and hot carcass weight were increased with pomegranate pulp supplementation. Compared to control lambs, the meat from lambs fed the supplemented diet had higher concentrations of intramuscular fat, mono- and polyunsaturated fatty acid, total unsaturated fatty acid, and meat phenolic compounds. Pomegranate pulp supplemented lambs also had a higher ratio of polyunsaturated to saturated fatty acids; and produced liver tissue with less fat and ash contents. Meat oxidative status (thiobarbituric acid reactive substance) and quality (water holding capacity, colour, and pH) were improved when lambs were supplemented with pomegranate pulp. These findings demonstrate that using pomegranate pulp as a feed for Ghezel lambs has advantageous effects on animal performance and meat quality, offering valorisation of an agrifood by-product.

Performance, digestibility and meat quality from lambs fed diets with plantago lanceolata, Italian ryegrass or sainfoin herbages.

Plantago species, which is known to adapt to different climatic conditions, drought, temperature and different soil types. The aim of this study was to compare the effects of P. lanceolata herbage on fattening performance, rumen variables, digestibility, meat quality, meat nutrients and meat textural variables in lambs with the values of Italian ryegrass and sainfoin herbages. The lambs were fed total mix ration (TMR) with concentrated feed (about 30%) plus forage (about 70%) (P. lanceolata, PLA, Italian ryegrass (Lolium multiflorum); IRY or sainfoin (Onobrychis viciifolia) herbages, SAI). Twenty-four male lambs (Akkaraman breed) were assigned to three treatments with 8 lambs in each group. Fattening performance parameters, digestibility and carcass variables were determined. Meat quality and shelf life variables (oxidation, fatty acid profile and textural variables) was detected in the loin (Musculus longissimus), shoulder (M. deltoideus) and leg (M. semitendinosus) muscle samples, which were rested for 24 h +4°C and stored at -20°C for one week, one month, three months and six months. The dry matter (DM) intake, body weight gain, feed efficiency and carcass yield values of lambs, the DM and organic matter (OM) digestions (DMD and OMD) of TMRs, and the pH value, ammonia-nitrogen and short chain fatty acid (SCFA) concentrations of rumen fluid in lambs consuming PLA were similar to those of IRY and SAI (p > 0.05). PLA increased water holding capacity (WHC) and decreased cooking loss of meat compared to feeding with those of IRY and SAI (p < 0.05). The peroxide value (PV) and malondialdehyde (MDA) concentration increased with the stocking time in the meats (p < 0.05). Therefore, PV and MDA concentrations of shoulder, leg and loin meats up to 6th months for PLA were lower than those of IRY and SAI (p < 0.05). The linoleic acid concentration of loin and shoulder meats in PLA were higher than those of IRY and SAI (p < 0.05). The average oleic acid and ∑ω6 fatty acids concentration of meat in PLA was lower than those in IRY and SAI (p < 0.05). Atherogenic index and thrombogenic index values and palmitic acid levels of meat in PLA were similar to those in IRY, but lower than those in SAI (p < 0.05). Springiness, cohesiveness, resilience, hardness and chewiness values of the textural analysis parameters in meat of PLA were lower than those of IRY and SAI. As a result, effect of P. lanceolata on the fattening performance and rumen fermentation of lambs were similar with those of Italian ryegrass (Gramineae family) and sainfoin (Leguminosae family) forages and, it had a positive effect on meat quality (water holding capacity, cooking loss) and meat shelf life criteria (MDA, PV, fatty acid profile and textural variables). For functional lamb meat production, P. lanceolata can be included in the diet of lamb fattening.

Can individual variation in food neophobia explain variability in dairy calf feeding behavior patterns and performance?

Food neophobia is the avoidance of novel feeds, arising from an attempt to avoid potentially toxic and unwanted feeds, and is very common in ruminants. In commercial dairy settings, hesitancy to consume novel feeds is detrimental to animal performance and may be associated with other traits that can negatively affect animals in intensive and modern production systems. The aim of this study was to investigate the relationship between food neophobia and the development of solid and milk feeding behaviors, and consequently with calf performance up to two weeks post-weaning. We subjected dairy calves at 83 ± 3 d of age to a food neophobia test with a novel feed (corn silage-based total mixed ration), a familiar feed (alfalfa hay), and an empty container. Behaviors measured from this food neophobia test were condensed into three factors using a principal component analysis: ‘Feed Avoidant’, ‘Active’, and ‘Attentive’. A regression analysis was performed to assess if scores for the three factors were associated with feeding behavior patterns measured via an automatic feeder system, including total milk intake, rewarded and unrewarded visits to the milk feeder, total calf starter intake, and age at which calves first consumed ≥ 1 kg of calf starter. Factor 1 (‘Feed Avoidant’) was positively associated with the number of rewarded visits to the automated milk feeder but was not associated with intake of calf starter or milk replacer, nor performance of dairy calves. The other factors identified from the food neophobia test showed associations with feeding behavior patterns and performance. Factor 2 (‘Active’) was positively associated with calf starter intake during the weaning, post-weaning, and total periods, and was associated with a younger age at which calves consumed 1 kg of calf starter. Factor 3 (‘Attentive’) was positively associated with number of rewarded visits to the feeder during preweaning, increased calf starter intake during weaning and total periods, and higher preweaning ADG. These results suggest that individual variation in the willingness to interact with novel and familiar feeds may not play a large role in the development of solid feeding behaviors or performance of group housed dairy calves, but other traits identified from the food neophobia test are associated with performance and feeding behavior that can be measured in standardized tests.

Effects of Supplementing Tributyrin on Meat Quality Characteristics of Foreshank Muscle of Weaned Small-Tailed Han Sheep Lambs.

This experiment aimed to evaluate the effects of supplementing tributyrin (TB) on the meat quality characteristics of foreshank muscle of weaned lambs. A total of 30 healthy weaned Small-Tailed Han female lambs with body weights ranging from 23.4 to 31.6 kg were selected and randomly divided into five groups, and each group consisted of 6 lambs. The control group was fed a basic total mixed ration, while other groups were fed the same ration supplemented with 0.5, 1.0, 2.0, and 4.0 g/kg TB, respectively. The experiment lasted 75 d, including 15 d of adaptation. Foreshank muscle obtained at the same position from each lamb was used for chemical analysis and sensory evaluation. The results showed that supplementing TB increased the muscle contents of ether extract (p = 0.029), calcium (p = 0.030), phosphorus (p = 0.007), and intermuscular fat length (p = 0.022). Besides, TB increased the muscle pH (p = 0.001) and redness (p < 0.001) but reduced the lightness (p < 0.001), drip loss (p = 0.029), cooking loss (p < 0.001), shear force (p = 0.001), hardness (p < 0.001), cohesiveness (p < 0.001), springiness (p < 0.001), gumminess (p < 0.001), and chewiness (p < 0.001). In addition, TB increased the muscle content of inosine-5'-phosphate (p = 0.004). Most importantly, TB increased the muscle contents of essential amino acids (p < 0.001). Furthermore, TB increased the saturated fatty acids level in the muscle (p < 0.001) while decreasing the unsaturated fatty acids content (p < 0.001). In conclusion, supplementing TB could influence the meat quality of foreshank muscle of weaned lambs by modifying the amino acid and fatty acid levels.

Influence of dietary Salicornia europaea L. extract supplementation on feed efficiency of Altay sheep by modifying their gastrointestinal bacteria communities.

This experiment aimed to examine the impact of Salicornia europaea L. extract on sheep growth performance, rumen fermentation variables, nutrient apparent digestibility, and gastrointestinal microbial diversity. Forty-eight male Altay sheep, weighing 32.5 ± 2.8 kg and approximately 3.5 months old, were chosen. Four dietary treatments, each consisting of four replicates and three sheep per replicate, were distributed randomly to the sheep. The pelleted total mixed ration containing Salicornia europaea L. extract at 0.0, 0.2, 0.4, and 0.6% DM was freely available to the sheep in the four treatment groups. The 56-day experiment consisted of 45 days of measurements followed by 11 days of adaptation. The growth performance was not affected by nutrition Salicornia europaea L. extract (p ≤ 0.05), but the feed-to-gain ratio was reduced when the extract was given at 0.4% DM (p ≤ 0.05). Compared to the 0 and 0.2% treatments, the apparent digestibility of DM, OM, NDF, and ADF was substantially greater in the 0.4, and 0.6% treatments. Furthermore, compared to sheep in the 0 and 0.2% groups, sheep in the 0.6% group had a noticeably higher apparent digestibility of CP. As the amount of Salicornia europaea L. extract added to the rumen fluid rose, the molar ratio of acetic acid increased. In contrast, the molar ratio of propionic acid gradually decreased, and the total volatile fatty acid content gradually reduced. Thus, adding a suitable quantity of Salicornia europaea L. extract to the sheep ration is natural and secure, which may improve the environmental sustainability of small ruminant production systems.

Effect of Total Mixed Ration on Growth Performance, Rumen Fermentation, Nutrient Digestion, and Rumen Microbiome in Angus Beef Cattle during the Growing and Fattening Phases

This study investigates the impact of varying concentrate levels in the diets of Angus beef cattle on their performance, nutrient digestion, and metabolism during the growth (7 to 12 months) and fattening (13 to 30 months) phases. Fifteen Angus steers were continuously fed and divided into low-concentrate (L) and high-concentrate (H) groups based on the fattening period and dietary formulations. Throughout each 9-week trial phase, a comprehensive range of parameters was systematically measured, including dry matter intake (DMI), average daily gain (ADG), gain-to-feed ratio (G/F), blood parameters, rumen fluid composition, and microbial diversity. In the fattening phases, an increase in concentrate levels resulted in a significant rise in the cattle’s DMI. Although there was a minor increase in ADG compared to the growing phases, this increase was not statistically significant. The efficiency of nitrogen (N) utilization in the cattle decreased, accompanied by a significant reduction in the apparent digestibility of nutrients. Ruminal fermentation produced more energy substances; however, there was a notable decrease in the abundance of fiber-decomposing microbes (such as the NK4A214_group, Ruminococcus, Papillibacter, and Acetitomaculum) and a significant increase in the abundance of starch-degrading microbes (including Bacteroidota and Prevotellaceae). Additionally, there was a significant reduction in the abundance of immune system-related functional pathways. This suggests that high-concentrate fattening does not necessarily lead to improved growth performance and may negatively affect metabolic health and nutrient digestion.

1H-NMR-Based Plasma Metabolomic Profiling of Crossbred Beef Cattle with Divergent RFI Phenotype

This study focused on exploring the metabolomic profiles of crossbred beef cattle with varying levels of residual feed intake (RFI), a measure of feed efficiency in beef cattle. Sixty-seven crossbred growing beef steers (BW = 277 ± 29.7 kg) were subjected to a high-forage total mixed ration for 64 days to determine their RFI phenotypes. At the end of the 64d feeding trial, beef steers were divided into two groups based on their RFI values: low (or negative)-RFI beef steers (n = 28; RFI = −1.08 ± 0.88 kg/d) and high (or positive)-RFI beef steers (n = 39; RFI = 1.21 ± 0.92 kg/d). Blood samples were collected, and plasma samples were analyzed using Nuclear Magnetic Resonance spectroscopy, resulting in the identification of 50 metabolites. The study found a distinct metabolomic signature associated with RFI status. Eight metabolites, including amino acids (tyrosine, glycine, valine, leucine, and methionine) and other compounds (dimethyl sulfone, 3-hydroxy isovaleric acid, citric acid, creatine, and L-carnitine), showed differential abundance between low- and high-RFI groups. Specifically, tyrosine, glycine, and dimethyl sulfone exhibited significant specificity and sensitivity, which produced a discriminatory model with an area under the receiver operating characteristic (ROC) curve of 0.7, making them potential markers for RFI. A logistic regression model incorporating these biomarkers effectively distinguished between high- and low-RFI steers, with a threshold cutoff point of 0.48, highlighting a distinctive metabolite profile associated with efficient nutrient utilization in low-RFI cattle. The logistic regression model, incorporating these biomarkers, holds promise for accurately categorizing RFI values, providing insights into the metabolic basis of feed efficiency in beef cattle.

Effect of feeding Bengal gram residual forage-based pelleted total mixed ration on growth performance, nutrient availability, carcass traits and composition in finisher Barbari kids.

The study aimed to assess the impact of feeding Bengal gram residual forage-based pelleted Total Mixed Ration (TMR) with varying concentrate (C) to roughage (R) ratios on feed intake, nutrient utilization, growth, and carcass characteristics in Barbari kids. Sixteen weaned male Barbari kids (av. age, 233 ± 11 days; weight, 13.86 ± 0.76kg) were divided into two groups (T1 and T2), each receiving different pelleted diets (TMR) with distinct concentrate to roughage ratios (T1 with 60:40; T2 with 40:60). The kids were fed for 133 days, and a digestion trial was conducted at the end of the study. After completion, all kids were slaughtered. Although, kids under T1 consumed higher (P < 0.001) amount of dry matter, and crude protein compared to T2, which was due to a higher concentrate to roughage ratio in T1. But, the average daily body weight gain (ADG) of finisher kids was 88.53, and 79.83g/d/kid in T1 and T2, respectively; however, the difference was non-significant. Digestibility of organic matter, crude protein, and total carbohydrate was also greater in T1 compared to T2. Total digestible nutrients intake was higher (P < 0.001) in T1; similarly intake of digestible energy, and metabolizable energy were significantly increased (P < 0.01) in T1 compared to T2. Concentrations of volatile fatty acids and NH3-nitrogen were also enhanced (P < 0.05) in T1 compared to T2. We observed similar carcass weight, and dressing percentage in both groups, and carcass composition remained unaffected. The pelleted diet containing greater ratio of concentrate: roughage (60:40) had no additional benefits in terms of ADG, and carcass traits in finisher kids. Therefore, it may be concluded that the Bengal gram residual forage-based pelleted TMR diet containing C40: R60 (TDN 57.13%, DCP 7.64%, ME 9.11MJ/kg feed) is suitable for optimizing growth performance with desirable carcass traits, and meat composition in finisher Barbari kids reared under the intensive system.

16S amplicon sequencing and untargeted metabolomics reveal changes in rumen microorganisms and metabolic pathways involved in the reduction of methane by cordycepin

As a major contributor to methane production in agriculture, there is a need for a suitable methane inhibitor to reduce ruminant methane emissions and minimize the impact on the climate. This work aimed to explore the influence of cordycepin on rumen fermentation, gas production, microbiome and their metabolites. A total of 0.00, 0.08, 0.16, 0.32, and 0.64 g L-1 cordycepin were added into fermentation bottles containing 2g total mixed ration for in vitro ruminal fermentation, and then the gas produced and fermentation parameters were measured for each bottle. Samples from the 0.00 and 0.64 g L-1 cordycepin addition were selected for 16S rRNA gene sequencing and metabolome analysis. The result of this experiment indicated that the addition of cordycepin could linearly increase the concentration of total volatile fatty acid, ammonia nitrogen, the proportion of propionate, valerate, and isovalerate, and linearly reduce ruminal pH and methane, carbon dioxide, hydrogen and total gas production, as well as the methane proportion, carbon dioxide proportion and proportion of butyrate. In addition, there was a quadratic relationship between hydrogen and cordycepin addition. At the same time, the relative abundance of Succiniclasticum, Prevotella, Rikenellaceae_RC9_gut_group, NK4A214_group, Christensenellaceae_R_7_group, unclassified_F082, Veillonellaceae_UCG_001, Dasytricha, Ophryoscolex, Isotricha, unclassified_Eukaryota, Methanobrevibacter, and Piromyces decreased significantly after adding the maximum dose of cordycepin. In contrast, the relative abundance of Succinivibrio, unclassified_Succinivibrionaceae, Prevotellaceae_UCG_001, unclassified_Lachnospiraceae, Lachnospira, Succinivibrionaceae_UCG_002, Pseudobutyrivibrio, Entodinium, Polyplastron, unclassified_Methanomethylophilaceae, Methanosphaera, and Candidatus_Methanomethylophilus increased significantly. Metabolic pathways such as biosynthesis of unsaturated fatty acids and purine metabolism and metabolites such as arachidonic acid, adenine, and 2′-deoxyguanosine were also affected by the addition of cordycepin. Based on this, we conclude that cordycepin is an effective methane emission inhibitor that can change the rumen metabolites and fermentation parameters by influencing the rumen microbiome, thus regulating rumen methane production. This experiment may provide a potential theoretical reference for developing Cordyceps byproduct or additives containing cordycepin as methane inhibitors.

Response to Incremental Replacement of Palm Oil with Fish Oil in Starter Diet on Growth Performance, Plasma Metabolites, Ruminal Fermentation, and Behavior of Dairy Calves.

The objective of this study was to evaluate the effects of the incremental levels of n-3 fatty acids (FA) in starter feed (SF) on growth and metabolic performance of milk-fed calves. From day 3 of age, 30 female calves (39.4 ± 3.1 kg of body weight) were randomly assigned to one of three dietary treatments: (1) SF supplemented with 3.3% palm fatty acids (PO), (2) SF supplemented with 1.7% of PO and 1.9% fish oil (PFO), or (3) SF supplemented with 3.9% fish oil (FO). Chopped straw (7.5% of DM) was included in the SF of all treatments as total mixed ration (TMR). Diets had similar energy and protein contents. Total n-3 FA (% of total FA) and n-6/n-3 of PO, PFO, and FO were 1.90, 6.80, and 11.8 and 15.5, 4.50, and 2.70, respectively. The BW was greater for calves receiving FO (60.2 ± 0.3 kg) compared with PFO (58.7 ± 0.3 kg; p = 0.007) and tended to be greater for calves receiving FO vs. PO (59.0 ± 0.3 kg; p = 0.050). Because there was no interaction effect between diet × week of experiment, the greater BW of FO could not be attributed to the dietary treatment. Accordingly, average daily gain, total dry matter intake (DMI), starter DMI, and gain to intake ratio (G:FI) did not differ among dietary treatments during the entire period of the study (p > 0.05). Dietary treatments did not impact body size parameters such as body length, body girth, withers height, heart girth, hip height, and width (p > 0.05). Neither ruminal fermentation parameters nor blood variables were influenced by supplementing the types of oil at different time points. Calves' behavioral parameters, such as standing, lying, eating, and ruminating, were not influenced by different dietary treatments (p > 0.05). The number of days with abnormal fecal score was not different among dietary groups (p > 0.05). Overall, our findings suggest that changing the n-6/n-3 ratio in starter feed by incremental replacement of palm fatty acid with fish oil at a moderate supplemental level of ~3% of DM may not affect the growth and metabolic performance of young calves under non-challenged conditions.

Optimization design and experiment of double-helix total mixed rations preparation mixer for silage straw feed

Aiming at the problems of uneven mixing and low production efficiency of domestic silage mixer, a double- helix TMR (Total Mixed Rations) preparation mixer for silage straw feed was designed to replace the traditional vertical single-helix mixer. The performance tests and parameter optimization were carried out on this preparation machine. By analyzing the mixing process and mechanism of the diets in the mixing chamber, the key factors affecting the mixing performance and the range were determined. It was found that the greater the stirring speed of the churn, the greater the angle of material lift, the more conducive to improving the material lifting capacity of the churn device. The mixing characteristics of the preparation machine and the movement of material were numerically simulated using EDEM simulation software, and the mixing effect of the preparation machine was verified. The three-factor and five-level CCD center combination orthogonal rotary test in the prototype was carried out with stirring speed of the churn, mixing time and filling coefficient as influencing factors, mixing uniformity, roughage particle size and ton material energy consumption as evaluation indexes. The test results showed that the contribution of each factor to the mixing uniformity in descending order was filling coefficient, stirring speed and mixing time, to the roughage particle size was stirring speed, mixing time and filling coefficient, and to the ton material energy consumption was filling coefficient, mixing time and stirring speed. The optimal working parameters for mixing performance by comprehensive optimization could be concluded as stirring speed of 48.59 r/min, mixing time of 14.98 min, and filling coefficient of 70%. In addition, the mixing uniformity, roughage particle size and ton material energy consumption were obtained as 91.11%, 72.13% and 2.99 kW·h/t. The relative error for all evaluation indexes between the experimental results with round parameter combination and the predicted value was verified to be less than 3%. It can be seen the double-helix TMR preparation mixer can meet the demand for efficient mixing of silage straw feed, which obviously provides data reference and technical support for the design and selection of operating parameters of TMR preparation machines.

Effects of three different grass silage-based total mixed rations on meat quality of finishing Holstein and Nordic Red dairy bulls

The objective of the present experiment was to study the effects of different silage-based diets on beef quality of Holstein (HO) and Nordic Red (NR) bulls. Moderate concentrate diet (MC) included grass silage (GS), barley grain and mineral-vitamin mixture in proportions of 600:385:15 on dry matter basis while the respective proportions on low concentrate diet (LC) were 850:135:15. No concentrate diet (NC) included GS, whole-crop barley silage and mineral-vitamin mixture (685:300:15). Thirty-five HO and 30 NR bulls (21–22 bulls per feeding treatment) were randomly selected for the meat quality research. One day post-slaughter, the muscle longissimus lumborum (LL) from the right side of each carcass was cut at the level of the first lumbar vertebra. The pH value of LL muscle was highest in LC, intermediate in MC and lowest in NC diet but did not differ between the breeds. For meat lightness a significant (P < 0.05) breed × diet interaction was observed. The NR bulls had lighter meat compared to the HO bulls especially with MC, but not with LC. Meat redness and yellowness were higher in MC compared to LC or NC fed bulls (P < 0.001). The breed did not affect meat redness, but yellowness was higher in HO compared to NR bulls (P < 0.05). Drip loss was higher in LL of HO than NR bulls (P < 0.01). The diets had no effects on marbling score but it was higher in NR than HO bulls (P < 0.05). Shear force was lowest in MC but no difference was found between the LC and NC and between the breeds. No differences between the treatments were found in sensory tenderness, juiciness, and flavour. Overall, the observed diet effects on meat eating quality were minor. This demonstrated the ability of finishing dairy bulls to adapt to different feedings without major effects on meat quality.

Supplementation of feedlot lambs with magnesium oxide and sodium bicarbonate: Effects on performance, nutrient digestibility, rumen environment, serum biochemistry and antioxidant indices

The present experiment was conducted to obtain an appropriate addition strategy of magnesium oxide (MgO) for feedlot lambs and to elucidate how the combined addition of MgO and sodium bicarbonate (NaHCO3) influences the growth performance and carcass characteristics of feedlot lambs. Sixty male Dorper-Hu hybrid lambs (32.76 ± 0.85 kg) were randomly assigned to 20 pens (3 lambs per pen; 5 pens per treatment). Lambs received a corn-based total-mixed ration (TMR, 80:20 concentrate to forage) without supplementation (CON) or with the inclusion (dry matter basis) of 15 g/kg NaHCO3 (SB), 2.5 g/kg MgO + 7.5 g/kg NaHCO3 (MG1) or 5 g/kg MgO + 7.5 g/kg NaHCO3 (MG2). Buffer addition effectively increased ruminal pH and water intake in feedlot lambs (P < 0.01). The MG2 group had lower dry matter intake (P ≤ 0.03), while the MG1 group showed higher average daily gain and lower feed-to-gain ratio than the other groups (P < 0.01). Compared to the CON and SB groups, MG1 and MG2 groups had greater total tract nutrient digestibility, except for the stage 1 of DM and ADF (P < 0.01). Adding MgO with NaHCO3 improved total volatile fatty acids concentration (P < 0.01). Microbial community analysis revealed enhanced Prevotella abundance in both MG1 and MG2 groups (P = 0.04). Additionally, MG1 and MG2 groups also both exhibited greater serum antioxidant capacity compared to CON and SB groups (P ≤ 0.03). The MG1 group showed greater dressing percentage, and ribeye area than other groups (P < 0.01). Overall, the recommended supplementation strategy for the lambs' diet was 2.5 g/kg MgO + 7.5 g/kg NaHCO3. The mixture of MgO and NaHCO3 enhanced the total tract nutrient digestibility, rumen fermentation, and serum antioxidant capacity in lambs, resulting in improved lamb growth and carcass performance.

Quality, Texture Profiles, Collagen Contents and Chemical Compositions of Meat from Thai Native Goats Fed with Different Protein Levels in Total Mixed Rations

Background: The main cost of animal production is the protein content in the feed. Hence, it is necessary to determine a suitable protein content for productive performance and meat quality of the Thai native goats. Methods: This study was carried out to investigate effects of protein levels in total mixed rations (TMR) on meat quality, texture, collagen contents and chemical compositions of Longissimus dorsi (LD) muscles of Thai native goats that were subjected to 4 alternative levels of protein in TMR (9, 12, 15 and 18%) for 4 months. Result: The results revealed that the pH1h and a* values were higher in goat meat from 18% dietary protein group (P less than 0.05). Regarding water holding capacity, it was found that the 12% dietary protein group had a higher thawing loss than the others (P less than 0.05). In texture profile analysis, the group that received the protein at 18% level had the higher in shear force than in the 9 and 12% dietary protein groups (P less than 0.05). For the chemical compositions, it was found that the 12% dietary protein group had highest insoluble collagen and total collagen contents. The protein levels of 15 and 18% gave the lowest fat content (P less than 0.05), followed by the dietary protein levels 12 and 9% in rank order. It can be concluded that increasing protein levels in TMR resulted in a redder meat but reduced tenderness and fat content of goat meat.