High-concentrate Diet Research Articles

PSIX-21 Can seeds rich in polyunsaturated fatty acids reduce methane emissions when substituting palm oil on dairy beef calves fed high-concentrate diets? In vitro screening

Abstract The aim of this study was to evaluate the rumen in vitro methane (CH4) production of concentrates feed with a different protein source (PS) replacing partially palm oil by different seeds (SE) rich in polyunsaturated fatty acids (PUFA). Concentrate PS were: T1 = 8% soybean meal; and T2 = 15% dried distillers grain. Palm oil (CTR; 4% and 3.5% for T1 and T2, respectively) was partially substituted (1%) by flax seed (FL; 2.7%), canola seed (CO; 3%) or sunflower seed (SU; 2.3%), thus 8 concentrates were tested. Samples were ground at 1-mm and used in an in vitro digestibility assay. The rumen liquid was obtained at the slaughterhouse. Two incubation sets were done; two sampling points lasted 24 and 48 h to calculate the dry matter (DM) digestibility; a third sampling point lasted 12 d to monitor the CH4 production. Data were analyzed using a mixed effects model. Net volume of CH4 per degraded DM presented a PS effect (P < 0.01); T1 produced greater net volume of CH4 per degraded DM than T2 (8.12 vs. 6.91 ± 0.330 ml/mg, respectively). Furthermore, net volume of CH4 per degraded DM presented a SE effect (P < 0.01); all concentrates with seeds tested reduced the net volume of CH4 per degraded DM compared with CTR, and specifically CO produced lower net volume of CH4 per degraded DM than FL and SU (8.91, 7.47, 6.28, 7.39 ± 0.467 ml/mg; CTR, FL, CO, SU, respectively). In conclusion, the use of flax, canola, or sunflower seeds to partially substitute palm oil in concentrate feed, regardless of its PS, can be potential strategies to reduce rumen CH4 emissions, and seems that canola seed may be the most effective one.

253 Effect of dietary straw withdrawal in high-concentrate diets on efficiency, carcass performance, rumen characteristics and seized livers in dairy beef crossbred bulls housed with straw bedding

Abstract The aim of this study was to evaluate the effect of dietary straw withdrawal in high-concentrate diets on efficiency, carcass performance, rumen characteristics and seized livers in dairy beef crossbred bulls housed with straw bedding. Bulls [n = 93; 335 ± 9.0 kg body weight (BW); 218 ± 4.0 d age] were group-housed in 6 straw-bedded pens according to 3 different feeding programs (2 pens/treatment): 1) CTR (n = 32), concentrate (13.1% CP, 5.9% fat content, 16.1% NDF, 40.8% starch content) and straw ad libitum fed in two separate feeders; 2) TSW (n = 32), like CTR, however, dietary straw withdrawal took place the first 84 study days; and 3) NSS (n = 29), concentrate with a reduced starch content (12.2% CP, 4.6% fat content, 22.0% NDF, 39.6% starch content) without dietary straw for the whole study. The study lasted 155 d divided into eleven 14-d periods. Individual concentrate intake was recorded daily, and dietary straw consumption was recorded per pen biweekly, as was individual BW. Carcass performance, rumen characteristics and seized organs were recorded at the slaughterhouse. Data were analyzed with a mixed-effects model. The first period was an adaptation where a dietary straw bale per pen was offered in all treatments; thereafter, only in CTR, and in TSW, after period 6. Treatment by period interactions (P < 0.01) in efficiency parameters were observed. Specifically, BW was greater in CTR than in TSW and NSS bulls while straw withdrawal periods; however, TSW bulls increased BW compared with NSS bulls when dietary straw was reintroduced, with final BW greater in CTR and TSW than in NSS bulls (569, 557 and 536 ± 8.0 kg, respectively). Regarding feed consumption, while dietary straw withdrawal for the first 6 periods, concentrate and straw intake were less in TSW and NSS than in CTR bulls, regardless the type of concentrate; after period 7, concentrate intake did not differ among treatments, and straw intake was greater in CTR and TSW than in NSS bulls, except in period 7, just after dietary straw reintroduction, that was greater in TSW than in CTR bulls. Hot carcass weight was greater (P < 0.01) in CTR than in TSW and NSS bulls (314, 296 and 299 ± 6.0 kg, respectively); dressing percentage was greater (P < 0.01) in CTR and NSS than in TSW bulls (55.1, 55.9 and 53.2 ± 0.65%, respectively); and carcass conformation tended (P = 0.06) to have greater classification in CTR bulls, and reduced classification in TSW bulls. Number of sized livers tended (P = 0.07) to be greater in NSS than in CTR and TSW bulls (22, 3 and 9%, respectively). In conclusion, short and long-term dietary straw withdrawal decreased animal and carcass performance regardless concentrate’s starch content in dairy beef crossbred bulls fed high-concentrate diets housed with straw bedding.

PSLBII-8 Evaluation of the in vitro ruminal methane production in heifers fed high-forage or high-concentrate diets during entire pregnancy

PSLBII-8 Evaluation of the in vitro ruminal methane production in heifers fed high-forage or high-concentrate diets during entire pregnancy

PSLBII-14 Impacts of limited feeding high-concentrate diets to beef heifers during the first 180 d of gestation on feeding behavior, carcass characteristics, and gastrointestinal tract morphometrics

PSLBII-14 Impacts of limited feeding high-concentrate diets to beef heifers during the first 180 d of gestation on feeding behavior, carcass characteristics, and gastrointestinal tract morphometrics

The Influence of High-Concentrate Diet Supplemented with Tannin on Growth Performance, Rumen Fermentation, and Antioxidant Ability of Fattening Lambs.

This experiment aimed to study the effects of tannin supplementation on growth performance, rumen fermentation characteristics, apparent digestibility and serum biochemistry, and antioxidant and immune indexes in fattening lambs. A total of 36 male Hu sheep lambs (body weight = 15.83 ± 0.48 kg and days of age = 55 ± 2 d) were fed a high-concentrate diet and randomly divided into one of three groups of 12 animals each: control with no tannin (CON) and tannin treatments (TA1, 3 g/d per lamb; TA2, 6 g/d per lamb). The feeding experiment lasted for 60 d. The results showed that the average daily gain and ruminal propionate content of lambs in the TA1 group were higher (p < 0.05) than those in the CON group. Lambs fed tannin had significantly increased (p < 0.05) microbial protein and decreased (p < 0.05) ammonia nitrogen concentrations in the rumen. In addition, the crude protein and neutral detergent fiber digestibility of the TA2 group were significantly decreased (p < 0.05) as compared with the TA1 and CON groups, respectively. The serum concentrations of triglyceride, immunoglobulin A, and catalase and the total antioxidant capacity were higher (p < 0.05) in the TA1 group that those in the CON group, whereas an opposite trend of urea nitrogen, interleukin-1β, and malondialdehyde was found between the two groups. Also, tannin supplementation increased (p < 0.05) Lactobacillus and decreased (p < 0.05) Salmonella counts in the feces of lambs. Taken together, tannin supplementation can improve the growth performance, immunity, and antioxidant ability of fattening lambs fed a high-concentrate diet.

Copaiba oleoresin as a substitute for sodium lasalocid in finishing diets for lambs: carcass characteristics and meat quality

ABSTRACT The aim of this study was to evaluate the effects of copaiba oleoresin (CO) as a substitute for sodium lasalocid on the carcass characteristics and meat quality of feedlot lambs fed a high-concentrate diet. Twenty-four Pantaneiro lambs, aged 152 days and weighing an initial body weight of 21.2 ± 3.9 kg, were distributed in a randomised block design with three treatments and eight replications. The treatments correspond to the additive supplements: LAS (22.5 mg of sodium lasalocid/kg of diet); CO-0.5 (0.5 mL of CO/animal/day); CO-1.0 (1.0 mL of CO/animal/day). The doses of CO were administered to the animals orally with the aid of a graduated syringe. Lambs supplemented with LAS had higher hot carcass weight, cold carcass weight, cold carcass yield, and degree of fattening compared to CO-0.5, while CO-1.0 did not differ from LAS. It can be concluded that daily ingestion of CO up to 1.0 mL/lamb did not negatively affect carcass characteristics when compared to LAS supplementation. However, lower ingestion (0.5 mL/day) can reduce the carcass weight and carcass yield. Although CO supplementation minimally affected the meat quality and FA profiles, both doses reduced crude protein content in meat.

Epigallocatechin-3-gallate protects bovine ruminal epithelial cells against lipopolysaccharide-induced inflammatory damage by activating autophagy

BackgroundSubacute ruminal acidosis (SARA) causes an increase in endotoxin, which can induce immune and inflammatory responses in the ruminal epithelium of dairy cows. In non-ruminants, epigallocatechin-3-gallate (EGCG), a major bioactive ingredient of green tea, is well-known to alleviate inflammation. Whether EGCG confers protection against SARA-induced inflammation and the underlying mechanisms are unknown.ResultsIn vivo, eight ruminally cannulated Holstein cows in mid-lactation were randomly assigned to either a low-concentrate (40%) diet (CON) or a high-concentrate (60%) diet (HC) for 3 weeks to induce SARA (n = 4). Cows with SARA had greater serum concentrations of tumor necrosis factor (TNF)-α and interleukin-6, and epithelium had histological signs of damage. In vitro, immortalized bovine ruminal epithelial cells (BREC) were treated with lipopolysaccharide (LPS) to imitate the inflammatory damage caused by SARA. Our data revealed that BREC treated with 10 µg/mL LPS for 6 h successfully induce a robust inflammatory response as indicated by increased phosphorylation of IκBα and nuclear factor kappa-B (NF-κB) p65. Pre-treatment of BREC with 50 µmol/L EGCG for 6 h before LPS challenge promoted the degradation of NLR family pyrin domain containing 3 (NLRP3) inflammasome through activation of autophagy, which further repressed activation of NF-κB pathway targeting Toll-like receptor 4 (TLR4). Analyses also revealed that the ECGG upregulated tight junction (TJ) protein expression upon incubation with LPS.ConclusionsSubacute ruminal acidosis causes ruminal epithelium injury and systemic inflammation in dairy cows. However, the anti-inflammatory effects of EGCG help preserve the integrity of the epithelial barrier through activating autophagy when BREC are exposed to LPS. Thus, EGCG could potentially serve as an effective therapeutic agent for SARA-associated inflammation.Graphical

Effect of butyrate sources in a high-concentrate diet on rumen structure and function in growing rams

Dietary butyrate is considered to have mostly positive impacts on the ruminal epithelium. However, its supplementation in a high-concentrate diet may not be justified as excessive ruminal butyrate may negatively affect the rumen. Furthermore, butyrate impact on the rumen may depend on its source. Thirty-two Świniarka growing rams (30.6 ± 2.5 kg; 11–14 months of age) were used to investigate the effect of a high-concentrate diet and sodium butyrate (SB) or tributyrin (TB) supplementation in a high-concentrate diet on the rumen structure and selected functions. The rams were allocated to four treatments and fed diets with: (1) low concentrate inclusion (22.5% of diet DM; L); (2) high concentrate inclusion (60% of diet DM; H); (3) H with SB (3.2% of diet DM; H+SB); and (4) H with TB (2.93% of diet DM; H+TB). The preplanned contrasts were used for treatment comparisons (L vs H treatments (H, H+SB, and H+TB), H vs H+SB, and H vs H+TB). The BW, BW gain and DM intake did not differ between treatments. In the atrium ruminis, epithelium thickness did not differ between the L and H treatments (P = 0.46), tended to be higher for H+SB than for H (P = 0.09) but did not differ between H+TB and H (P = 0.61). The expression of downregulated in adenoma was higher for L than for H treatments (P = 0.03) but was not affected by SB or TB supplementation (P ≥ 0.26). In the ventral rumen, the mucosa surface and epithelium thickness were lower for L than for H treatments (P < 0.01), were or tended to be higher for H+SB than for H (P ≤ 0.06) but did not differ between H+TB and H (P ≥ 0.26). The expression of monocarboxylate transporter 1 was lower for L than for H treatments (P = 0.02) but was not affected by SB or TB supplementation (P ≥ 0.28). The expression of putative anion transporter-1 and downregulated in adenoma did not differ between the L and H treatments (P ≥ 0.76); however, expression of the former tended to be higher and the latter tended to be lower for H+SB than for H (P ≤ 0.09), whereas no differences were observed between H+TB and H (P ≥ 0.14). In summary, SB supplementation, but not TB supplementation, in a high-concentrate diet stimulated ruminal epithelium growth and affected short-chain fatty acid transporters expression in the ruminal epithelium.

Subacute Rumen Acidosis in Greek Dairy Sheep: Prevalence, Impact and Colorimetry Management.

Subacute rumen acidosis (SARA) is a current issue in intensive livestock farming, and it is particularly associated with feeding high-concentrate diets. This study investigated the prevalence and impact of SARA in forty-two Greek dairy sheep flocks by recording rumen pH, milk composition, and milk yield over a period of nine months. Moreover, it explored the use of computerized rumen colorimetry as a management and diagnostic tool for SARA in dairy sheep. In culled ewes, computerized rumen mucosal colorimetry was applied, and rumen wall samples taken for histological examination. SARA cases were identified in 19 farms (45%, n = 42). Farms with SARA cases had lower milk fat levels, while milk yield and milk protein levels did not differ based on the SARA status of the farms. In culled ewes, rumen color was significantly associated with the flock's SARA status, and affected ewes showed increased thickness in non-keratinized and total epithelial layers. It was concluded that computerized rumen mucosal colorimetry in aged, culled ewes shows promise as an indicator, post mortem, of SARA present in dairy sheep flocks whose impact can be minimized by making significant changes in dietary management.

Chlorine dioxide may be an alternative to acidification and chlorination for drinking water chemical disinfection in dairy beef bulls

Alternative water disinfectants to chlorination need to be identified because its effectiveness is limited by water pH and potentially carcinogen by−products resulted from chlorination and organic compound reaction. The first study aimed to evaluate the effect of different drinking water chemical disinfection treatments on water quality, its potential hazard effects on animal health, water and feed consumption, and apparent total tract digestibility in dairy beef bulls fed high-concentrate diets. For 224 days, 24 Holstein bulls (176 ± 16.3 kg BW, and 149 ± 5.8 days of age) were individually assigned to one of four treatments with different drinking water chemical disinfectants: without disinfection (CTR); acidification and chlorination (ACCHL; 0.65 mL/L H3PO4 and 0.14 mL/L NaClO 15%); hydrogen peroxide (PER; 0.15 mL/L); and chlorine dioxide (DIO; 2.50 mL/L). Data were analysed with a mixed-effects model. Treatments affected the chemical characteristics of the water: in ACCHL, pH was 6.60 and free residual chlorine was 0.75 mg/L; in PER, H2O2 was 10.6 mg/L; and in DIO, ClO2 was 0.52 mg/L. Water physicochemical quality parameters in all treatments were below maximal thresholds established for safe water consumption by the Water Safety Royal Decree (RD 140/2003). In addition, the total coliform count of treated waters was reduced (P = 0.01) compared with CTR; moreover, ACCHL and DIO treatments were more effective in reducing total coliform count than PER. Dry matter intake tended (P = 0.07) to increase in DIO compared with CTR. Treatments did not affect blood parameters nor apparent total tract digestibility. The second study aimed to evaluate the potential benefit on animal performance of two drinking water disinfectants under commercial conditions in dairy beef crossbred Holstein bulls fed high-concentrate diets. Ninety-six animals (307 ± 4.4 kg BW, and 224 ± 1.8 days of age) were allocated to six pens for 140 days and assigned to one of two treatments: ACCHL, most common water disinfectant, and DIO. Data were analysed with a mixed-effects model. Water total coliform count and water consumption were similar between treatments. Concentrate intake was greater (P = 0.02) in ACCHL for the last 14 study days. Growth performance and carcass quality were similar between treatments. In summary, acidification and chlorination, H2O2, and ClO2 as drinking water disinfectants in dairy beef bulls had good disinfecting activity without detrimental effects on health and nutrient digestibility, and performance.

Impact of replacing protein pellets with soybean grain on nutrient utilization and the rumen and blood parameters of feedlot cattle under tropical conditions.

The aim of this study was to explore the effect of replacing protein pellets with soybean grain in high-concentrate diets with or without the addition of silage, on the intake, digestibility, and rumen and blood parameters of feedlot cattle in tropical regions. Four cannulated, crossbred steers were used, 4.5 ± 0.5 years old, with an average weight of 685.55 ± 111.78kg. The steers were distributed in a 4 × 4 Latin square, in a 2 × 2 factorial scheme (two sources of protein: protein pellets or whole soybean grain, with or without added dietary bulk). There was no effect (P ≥ 0.109) from the interaction between the source of protein and the addition of silage to the diet on dry matter (DM) and nutrient intake, or the digestibility (P ≥ 0.625) of DM or crude protein (CP). However, both factors affected (P ≤ 0.052) the intake of DM, neutral detergent fiber (NDF), and non-fiber carbohydrates (NFC), as well as the independent digestibility (P ≤ 0.099) of fat, NFC, total carbohydrates (TC), and total cholesterol concentration. There was an effect (P ≤ 0.053) from the interaction between the source of protein and the addition of silage to the diet on the digestibility of NDF and total digestible nutrients (TDN), as well as on the glycose concentration (P = 0.003). Blood parameters (i.e. protein, albumin, creatinine, triglycerides, aspartate aminotransferase (AST), and alanine aminotransferase (ALT)) were not affected (P ≥ 0.139) by the source of protein, the addition of silage, or their interaction. Lastly, including 150g/kg silage DM in a high-grain diet, and using soybean grain as a source of protein in substitution of protein pellet could be a suitable nutritional strategy to ensure adequate DM and nutrient intake and digestibility, with no detrimental effects on rumen and blood parameters of feedlot cattle in the tropics.

Plasma concentration of serum amyloid A and lipopolysaccharide binding protein in horses with laminitis resulted from hindgut acidosis

Many studies have shown a strong correlation between Hindgut Acidosis (HGA) and the occurrence of laminitis in horses; therefore, the early diagnosis of HGA is essential. In this study, we investigated changes in the plasma concentrations of lipopolysaccharide-binding protein (LBP) and serum amyloid A (SAA) as inflammatory markers in horses with laminitis. Sixteen healthy male Arabian horses that had cecal cannulation without visible laminitis or general symptoms were randomly divided into two groups. The horses were fed two different diets in a forage-to-concentrate ratio. Blood samples were collected on Days 1, 10, and 20. The primary objective of this study was to analyze plasma levels of LBP and SAA. Cecal specimens were obtained from each equine subject on three designated days: days 1, 10, and 20. The second objective was to assess the levels of pH and volatile fatty acids (VFA) in the samples. Throughout the study period, horses fed a high-concentrate diet exhibited a significantly elevated average lameness grade on days 10 and 20 compared to the initial stage (P < 0.001). On day 20, a significant increase in the concentration of SAA was observed in horses fed a high-concentrate diet, in contrast to the initial stage of the study. LBP levels in the plasma were significantly elevated on days 10 and 20 in horses fed a high-concentrate diet. Based on our findings, it is recommended that the evaluation of plasma LBP concentrations is more effective than SAA for the early identification of HGA in horses fed a high-grain diet.

Prolonged feeding of high-concentrate diet remodels the hindgut microbiome and modulates nutrient degradation in the rumen and the total gastrointestinal tract of cows

The aims of this research were to evaluate how prolonged feeding of a high-concentrate diet affects the ruminal degradation kinetics of fiber and starch, and to evaluate the effects of the high-concentrate diet on apparent total-tract nutrient digestibility in dairy cows. We also investigated the dysbiotic effects and the remodeling of the hindgut microbiome with prolonged high-concentrate feeding. Nine Holstein cows were used in 2 experimental periods; in each period, cows were first fed a 100% forage diet for 1 wk, followed by stepwise adaptation during one week to a high-concentrate (HC) diet (65% concentrate), which was then fed for 4 consecutive weeks. The kinetics of in situ ruminal degradability of grass silage (DM and NDF), corn grain and wheat grain (DM and starch), as well as the apparent total-tract nutrient digestibility were evaluated in the forage feeding and in wk 4 on the HC diet. Whereas the hindgut microbiome and fermentation profile were evaluated on a weekly basis. Regarding the in situ ruminal degradability due to grain type, the rate of degradation of the potentially degradable fraction and the effective rumen degradability of wheat grain were greater compared with corn grain. The in situ ruminal degradability of NDF decreased with the HC diet. However, the apparent total-tract digestibility of CP, fat, starch, NDF, ADF, and NFC increased with the HC diet compared with forage feeding. In addition, the HC diet increased the concentration of short-chain fatty acids in the hindgut, lowering fecal pH by 0.6 units, which correlated positively with microbial α diversity. This resulted in lower α diversity with the HC diet; however, α diversity (number of amplicon sequence variants) showed recovery in wk 3 and 4 on HC; in addition, microbial β diversity did not change from wk 2 onward on the HC diet. Two microbial enterotypes were identified: one for the forage diet with abundance of Akkermansia and Anaerosporobacter, and another enterotype for the HC diet with enrichment in Bifidobacterium and Butyrivibrio. Overall, results show that major microbial shifts and hindgut dysbiosis occurred in wk 1 on the HC diet. However, the hindgut microbial diversity of cows adapted after 3 wk of consuming the starch-rich ration. Thus, feeding the HC diet impaired fiber degradation in the rumen, but increased apparent total-tract nutrient digestibility. Likely, the forage diet contained less digestible NDF than the HC diet due to greater inclusion of forages with lower NDF digestibility and lower inclusion of more digestible nonforage NDF. Results also suggest that the adaptation of the hindgut microbial diversity of cows observed 3 weeks after the diet transition likely contributed to enhance total-tract nutrient digestibility.

Dry distillers grain with high fiber solubles replacing corn grain in confined sheep diets

In Brazil, the meat production market has intensified, with more and more improvements being sought every day in the production system to maintain greater economic viability. Therefore, initially, there is greater attention to animal nutrition, using different food sources to ensure good animal performance. As a result, the search for alternative foods has been highlighted due to the good dietary energy components for ruminants. The objective was to evaluate inclusion levels of dried distillers grain with high fiber solubles (DDGS FS OURO®) in the diet of confined sheep regarding nutrient consumption characteristics. Eight animals of the Santa Inês breed were used, males, castrated, with an initial body weight of 30 kg, aged 7 months. The animals were distributed in a double 4x4 Latin square design, with 4 experimental periods of 21 days each, with 16 days of adaptation and 5 days for sample collection. The treatments consisted of the inclusion of 20, 40, 60 and 80% of DDGS high fiber in dry matter, in high concentrate diets. The inclusion of DDGS did not influence the consumption of DM (kg/day), DM (% BW), MO (kg/day) and CP (kg/day), with average values of 1.42; 3.55; 1.23 and 0.264, respectively. Regarding the consumption of NDF and iNDF, a linear increase can be noted with the inclusion of DDGS. The inclusion of dry distillers grain with high-fiber solubles favored a greater consumption of neutral detergent fiber without changing the consumption of dry matter, which for a high-concentrate diet would be interesting to reduce the risk of acidosis.

Effects of different concentrate levels in AGRI-002E sorghum silage-based diets on nutrient intake and digestibility, ruminal pH and ammonia concentration, ruminal degradability, and microbial efficiency in beef cattle

This study aimed to evaluate the effect of increasing concentrate levels in AGRI-002E sorghum silage (SS)-based diets on nutrient intake and digestibility, ruminal pH and ammonia concentration, Nitrogen (N) balance, efficiency of microbial protein synthesis, and in situ degradability of complete diets. Five rumen-cannulated Nellore bulls (age = 8 ± 1.0 months; initial BW = 242 ± 5 kg) received five dietary treatments in a 5×5 Latin square experimental design. The dietary treatments consisted of five concentrate levels (0, 200, 400, 600, and 800 g of concentrate/kg on a DM basis) in SS-based diets. The experiment lasted 120 d, with five periods of 24 d. Each period consisted of 17 d for dietary adaptation, and 7 d for data collection. In situ degradability assays were conducted to estimate ruminal degradability. Total feces and urine collection were performed to estimate nutrient intake and digestibility and estimate N balance. Omasal and ruminal digesta collection were performed to estimate ruminal digestibility and ruminal parameters. Increasing concentrate levels in SS-based diets led to linear increases (P<0.001) in the intake of dry matter (DM), organic matter (OM), crude protein (CP), and ether extract (EE). Neutral detergent fiber corrected for ash and protein contamination (apNDF) and starch intake showed quadratic responses (P≤0.008). Ruminal digestibility of DM, OM and CP responded quadratically (P≤0.040), while apNDF exhibited linear decrease (P=0.003). Starch ruminal digestibility exhibited a cubic effect (P=0.016). Apparent total-tract digestibility of DM, OM, and EE increased linearly (P≤0.001), whereas apNDF, and CP digestibility decreased linearly (P≤0.012), and starch presented a quadratic effect (P=0.029). In situ ruminal degradation parameters increased linearly with higher concentrate levels (P<0.001). Ruminal pH exhibited a quadratic pattern (P=0.006), ammonia concentration linearly decreased (P=0.003). Total volatile fatty acids, and butyrate showed linear increases (P<0.001), acetate and propionate had quadratic effects (P<0.001), while the ratio Acetate to Propionate decreased linearly (P<0.001). N intake, fecal N excretion, retained N, total digestible nutrients, digestible organic matter, and microbial production increased linearly (P<0.001), although urine N excretion, urinary urea, and blood urea concentration decreased linearly (P<0.028). Therefore, increasing concentrate levels in AGRI-002E sorghum silage-based diets improve TDN intake, microbial protein synthesis efficiency, in situ ruminal degradability parameters, and nitrogen utilization. Moreover, our findings indicate that AGRI-002E sorghum silage demonstrates potential as a fiber source for high-concentrate diets. However, its effectiveness is limited without concentrate supplementation, emphasizing the importance of balanced dietary composition for optimal utilization in beef cattle.

Effects of Dandelion Extract on Promoting Production Performance and Reducing Mammary Oxidative Stress in Dairy Cows Fed High-Concentrate Diet.

This study investigated the effects of rumen bypass dandelion extract on the lactation performance, immune index, and mammary oxidative stress of lactating dairy cows fed a high-concentrate diet. This study used a complete randomized block design, and initial milk production, somatic cell counts, and parities were set as block factors. Sixty Holstein cows with similar health conditions and lactating periods (70 ± 15 d) were divided into three groups with 20 replicates per group. The treatments included the LCD group (low-concentrate diet, concentrate-forage = 4:6), HCD group (high-concentrate group, concentrate-forage = 6:4), and DAE group (dandelion aqueous extract group, HCD group with 0.5% DAE). The experimental period was 35 d, and cows were fed three times in the morning, afternoon, and night with free access to water. The results showed the following: (1) Milk production in the HCD and DAE groups was significantly higher (p < 0.05) than that in the LCD group from WK4, and the milk quality differed during the experimental period. (2) The HCD group's pH values significantly differed (p < 0.01) from those of the LCD and DAE groups. (3) In WK2 and WK4 of the experimental period, the somatic cell counts of dairy cows in the HCD group were significantly higher (p < 0.05) than those in the DAE group. (4) The serum concentrations of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and protein carbonyl (PC) in the HCD group were significantly higher (p < 0.05) than those in the LCD group. The activity of catalase (CAT) in the LCD and DAE groups was stronger (p < 0.01) than that in the HCD group. (5) The correlation analysis revealed significantly positive correlations between the plasma LPS concentration and serum concentrations of 8-OHdG (p < 0.01), PC (p < 0.01), and malondialdehyde (MDA, p < 0.05) and significantly negative correlations (p < 0.01) between the plasma LPS concentration and activities of CAT and superoxide dismutase. (6) Compared with that in the HCD and DAE groups, the mRNA expression of α, β, and κ casein and acetyl CoA carboxylase in bovine mammary epithelial cells was significantly higher (p < 0.05) in the LCD group, and the mRNA expression of fatty acid synthetase and stearoyl CoA desaturase in the LCD group was significantly higher (p < 0.01) than that in the HCD group. (7) Compared with that in the LCD and HCD groups, the mRNA expression of Nrf2 was significantly higher (p < 0.01) in the DAE group, and the mRNA expression of cystine/glutamate transporter and NAD (P) H quinone oxidoreductase 1 in the DAE group was significantly higher (p < 0.05) than that in the HCD group. Overall, feeding a high-concentrate diet could increase the milk yield of dairy cows, but the milk quality, rumen homeostasis, and antioxidative capability were adversely affected. The supplementation of DAE in a high-concentrate diet enhanced antioxidative capability by activating the Nrf2 regulatory factor and improved rumen homeostasis and production performance.

Disturbances of Ruminal Microbiota and Liver Inflammation, Mediated by LPS and Histamine, in Dairy Cows Fed a High-Concentrate Diet.

The ecosystem of ruminal microbiota profoundly affects the health and milk production of dairy cows. High-concentrate diets are widely used in dairy farms and evoke a series of metabolic disorders. Several studies have reported the effects of high-concentrate diets on the ruminal microbiome, while the effect of changes in ruminal microbial flora, induced by high-concentrate diet feeding, on the liver of dairy cows has not been studied before. In this study, 12 mid-lactating Holstein Friesian cows (weight of 455 ± 28 kg; parities of 2.5 ± 0.5; starting milk yield of 31.59 ± 3.2 kg/d; DMI of 21.7 ± 1.1 kg/d; and a DIM at the start of the experiment of 135 ± 28 d) were fitted with ruminal fistulas, as well as with portal and hepatic vein catheters. All cows were randomly divided into 2 groups; then, they fed with low-concentrate diets (LC, concentrate: forage = 40:60) and high-concentrate diets (HC, concentrate: forage = 60:40) for 18 weeks. The forage sources were corn silage and alfalfa hay. After the cows of two groups were euthanized over two consecutive days, ruminal microbiota; the concentration of LPS in the rumen content; cecum content; the levels of blood and histamine in rumen fluid, blood, and the liver; the histopathological status of the rumen and cecum; and the inflammatory response of the liver were assessed in dairy cows under conditions of subacute ruminal acidosis (SARA). These conditions were caused by high-concentrate diet feeding. All data were analyzed using the independent t-test in SPSS. The results showed that high-concentrate diet feeding increased the concentration of LPS and histamine in the rumen and plasma of veins (p < 0.05). The abundance of Bacteroidetes at the phylum level, and of both Bacteroidetes and Saccharibacteria at the genus level, was decreased, while the abundance of Firmicutes at the phylum level and Oscillibacter at the genus level was increased by high-concentrate diet feeding. The decreased pH values of ruminal contents (LC = 6.02, HC = 5.90, p < 0.05) and the increased level of LPS in the rumen (LC = 4.921 × 105, HC = 7.855 × 105 EU/mL, p < 0.05) and cecum (LC = 11.960 × 105, HC = 13.115 × 105 EU/mL, p < 0.01) induced the histopathological destruction of the rumen and cecum, combined with the increased mRNA expression of IL-1β (p < 0.05). The histamine receptor H1R and the NF-κB signaling pathway were activated in the liver samples taken from the HC group. In conclusion, the elevated concentrations of LPS and histamine in the gut may be related to changes in the ruminal microbiota. LPS and histamine induced the inflammatory response in the ruminal epithelium, cecum epithelium, and liver. However, the cause-effect mechanism needs to be proved in future research. Our study offers a novel therapeutic strategy by manipulating ruminal microbiota and metabolism to decrease LPS and histamine release and to improve the health of dairy cows.

Feedlot performance of Nellore bulls fed high-concentrate diets containing the association of tannins and saponins with sodium monensin

Feedlot performance of Nellore bulls fed high-concentrate diets containing the association of tannins and saponins with sodium monensin

Acid-base properties of non-protein nitrogen affect nutrients intake, rumen fermentation and antioxidant capacity of fattening Hu sheep.

This study conducted a comparison of the effects of non-protein nitrogen with different acid-base properties on feed intake, rumen fermentation, nutrient digestion and antioxidant capacity in fattening Hu sheep. Sixteen fattening male sheep (31.43 ± 2.41 kg) with permanent rumen cannulas were randomly assigned to two dietary treatments: 1% urea and 1.78% ammonium chloride (NH4Cl, AC). A 42 days experimental period was conducted, with 14 days for adaptation and 28 days for treatment. Daily feed intake was recorded and various samples including feed, feces, rumen fluid, and blood were collected at different time points during the final week. The results indicated that the urea group had significantly higher dry matter intake, average daily gain, and gain efficiency in comparison to the AC group (p < 0.01). There was no difference in rumen pH and concentration of ammonia nitrogen between different groups (p > 0.05), but the rumen pH of urea group was higher than that of the AC group at 1 and 3 h after feeding (p < 0.05). The urea group exhibited higher concentrations of total volatile fatty acids (VFA) and individual VFAs compared to the AC group at all-time points (p < 0.01). Compared to the urea group, the intake of all nutrients decreased in the AC group (p < 0.01), but the digestibility of dry matter and organic matter increased significantly (p < 0.01), and the digestibility of CP had an increasing trend (p = 0.06) in the AC group. Additionally, the urea group had lower levels of serum glucagon-like peptide-1, peptide YY, Cl, total protein and globulin than the AC group (p < 0.05). The overall levels of HCO3-, superoxide dismutase, glutathione peroxidase, catalase, albumin/globulin, blood urea nitrogen and total cholesterol in the urea group increased significantly compared to the AC group (p < 0.05). It was concluded that adding urea to the high-concentrate diet resulted in increased rumen pH and improved rumen fermentation and growth performance in fattening sheep compared to NH4Cl addition. Furthermore, urea addition improved sheep's antioxidant capacity and maintained their acid-base balance more effectively as compared to NH4Cl.

Influence of BOVAMINE DEFEND Plus on growth performance, carcass characteristics, estimated dry matter digestibility, rumen fermentation characteristics, and immune function in finishing beef steers.

One hundred and eighty crossbred beef steers (406.0 ± 2.2kg) were used to determine the impact of a novel direct-fed microbial (DFM) on growth performance, carcass characteristics, rumen fermentation characteristics, and immune response in finishing beef cattle. Steers were blocked by body weight (BW) and randomly assigned, within block, to 1 of 2 treatments (3 replicates/treatment: 30 steers/replicate). Treatments included: (1) no DFM (control) and (2) DFM supplementation at 50 mg ∙ animal-1 ∙ d-1 (BOVAMINE DEFEND Plus). All steers were fed a high-concentrate finishing diet and individual feed intake was recorded daily via the GrowSafe system. BWs were collected every 28 d. On day 55, 10 steers per pen were injected with ovalbumin (OVA). Jugular blood samples were collected from each steer on days 0, 7, 14, and 21 post injection. On day 112, the same steers were injected again with OVA and intramuscularly with a pig red blood cell solution. Jugular blood samples were collected from each steer on days 0, 7, 14, and 21 post injection. On day 124, rumen fluid was collected from 3 steers per treatment and used to estimate in vitro rumen fermentation characteristics. Equal numbers of steers per treatment were transported to a commercial abattoir on days 145, 167, and 185 of the experiment, harvested, and carcass data were collected. Initial BW was similar across treatments. On days 28 and 55, steers receiving DFM had heavier BW (P < 0.01) compared to controls. The average daily gain was greater in DFM-supplemented steers from days 0 to 28 (P < 0.01) and days 0 to 55 (P < 0.01) of the experiment compared to controls. Overall dry matter intake (DMI) was greater (P < 0.04) and overall feed efficiency was similar in DFM-supplemented steers compared to controls. Dressing percentage (P < 0.02) was greater in steers receiving DFM compared to controls. Antibody titers to injected antigens were similar across treatments. However, red blood cell superoxide dismutase activity was greater (P < 0.05) in DFM-supplemented steers compared to controls. In vitro molar proportions of isobutyric and butyric acid were greater (P < 0.01) and dry matter (DM) digestibility tended (P < 0.07) to be greater in rumen fluid obtained from steers supplemented with DFM. These data suggest that BOVAMINE DEFEND Plus supplementation improves growth performance during the initial period of the finishing phase, increases overall DMI and dressing percentage, and may impact antioxidant status in beef cattle.