High-concentrate Diet Research Articles

Effects of Noni (Morinda citrifolia L.) Fruit Extract Supplemented in Cashmere Goats with a High-Concentrate Diet on Growth Performance, Ruminal and Colonic Fermentation and SARA.

This experiment was conducted to investigate the effects of noni fruit extract (NFE) on growth performance, ruminal and colonic fermentation, nutrient digestion, and subacute rumen acidosis (SARA) of cashmere goats with the high-concentrate diet. Twenty-four cashmere kids (17.9 ± 1.45 kg of BW ± SD) were randomly assigned to three treatments: low-concentrate diet, high-concentrate (HC) diet, or HC diet supplemented with NFE at 1 g per kg DM (0.1%). The results showed that although the HC diet improved the average daily gain (ADG) and feed conversion rate (FCR), it was accompanied by SARA with a decreased pH and an increased lactic acid of both rumen and colon, and decreased digestibility of neutral detergent fiber (NDF)and acid detergent fiber (ADF). The supplementation of 0.10% NFE in the HC diet could not only effectively alleviate SARA symptoms and colon fermentation disorders, such as reversing the decrease of pH and alleviating the increase of lactic acid in rumen and colon, but also mitigate the decline of fiber digestibility caused by long-term feeding in the HC diet, and increase the digestibility of crude protein(CP) and dry matter (DM), which improved the ADG and FCR of cashmere kids. Thus, NFE provides new strategies for alleviating SARA and promoting cashmere goat growth.

Does Replacing Maize with Barley Affect the Animal Performance and Rumen Fermentation, including Methane Production, of Beef Cattle Fed High-Concentrate Diets On-Farm?

Ruminants fed high-concentrate diets produce less enteric methane than those fed high-forage diets, but not all grains are equally effective in reducing methane production. This study aimed to examine, in farm conditions, the effects of a partial substitution of maize with barley on animal performance and rumen fermentation, including methane production, of intensively reared beef calves (ca. 0.9:0.1 concentrate to forage ratio). Ninety-six beef calves were fed a concentrate with 45.5% maize and 15% barley (n = 48; M) or a concentrate with 15.5% maize and 45% barley (n = 48; B). Both the concentrate and barley straw were offered ad libitum. The type of concentrate did not have a significant effect (p > 0.05) on final live weight, average daily gain, carcass dressing percentage or intake of concentrate and straw. Dry matter and organic matter digestibility were higher (p < 0.05) for the M (75.4% and 76.6%) than for the B (71.0% and 73.1%) treatment, but with no effect on digestible organic matter intake. In general, the majority cereal in the concentrate did not affect rumen fermentation, including methane production, or the degradability of dry matter and starch. A partial substitution of maize with barley in the concentrate offered to beef calves does not seem a promising strategy to decrease the emissions of enteric methane on-farm.

Acid tolerance of lactate-utilizing bacteria of the order Bacteroidales contributes to prevention of ruminal acidosis in goats adapted to a high-concentrate diet.

The rapid accumulation of organic acids, particularly lactate, has been suggested as the main cause of ruminal acidosis (RA) for ruminants fed high-concentrate diets. Previous research has shown that a gradual shift from low-to high-concentrate diets within 4 to 5 weeks effectively reduces the risk for RA. However, the mechanisms remain unknown. In this study, 20 goats were randomly allocated into four groups (n=5) and fed with a diet containing a weekly increasing concentrate portion of 20%, 40%, 60%, and 80% over 28d. At d 7, 14, 21, and 28, one group (named C20, C40, C60, and C80 according to the last concentrate level that they received) was killed and the ruminal microbiome was collected. Ruminal acidosis was not detected in any of the goats during the experiment. Nonetheless, ruminal pH dropped sharply from 6.2 to 5.7 (P<0.05) when dietary concentrate increased from 40% to 60%. A combined metagenome and metatranscriptome sequencing approach identified that this was linked to a sharp decrease in the abundance and expression of genes encoding nicotinamide adenine dinucleotide (NAD)-dependent lactate dehydrogenase (nLDH), catalyzing the enzymatic conversion of pyruvate to lactate (P<0.01), whereas the expression of two genes encoding NAD-independent lactate dehydrogenase (iLDH), catalyzing lactate oxidation to pyruvate, showed no significant concomitant change. Abundance and expression alterations for nLDH- and iLDH-encoding genes were attributable to bacteria from Clostridiales and Bacteroidales, respectively. By analyzing the gene profiles of 9 metagenome bins (MAG) with nLDH-encoding genes and 5 MAG with iLDH-encoding genes, we identified primary and secondary active transporters as being the major types of sugar transporter for lactate-producing bacteria (LPB) and lactate-utilizing bacteria (LUB), respectively. Furthermore, more adenosine triphosphate was required for the phosphorylation of sugars to initiate their catabolic pathways in LPB compared to LUB. Thus, the low dependence of sugar transport systems and catabolic pathways on primary energy sources supports the acid tolerance of LUB from Bacteroidales. It favors ruminal lactate utilization during the adaptation of goats to a high-concentrate diet. This finding has valuable implications for the development of measures to prevent RA.

Açai seed as a fiber source in high-concentrate beef cattle diets and its nutritional effects

This study evaluated the effects of different levels of inclusion of coarsely broken açai seed (CBAS) in the diet of feedlot beef cattle on the intake, digestibility, ruminal degradation, passage kinetics, and nitrogen utilization efficiency. Five ruminally fistulated crossbred bulls (387±27kg body weight) were used in a 5×5 Latin square design. A total mixed ration with 750g/kg concentrate and 250g/kg roughage, based on the total dry matter (DM), was used. The treatments consisted of the inclusion of CBAS at 0, 50, 100, 150, and 200g/kg DM as a fiber source in the diet. The roughage used was Mombasa grass silage, which was partially replaced by CBAS. A linear increase in organic matter (OM; P=0.042), crude protein (CP; P=0.023), and neutral detergent fiber (NDF; P=0.022) intake was observed with the inclusion of CBAS in the diet, while a linearly increasing trend was observed for DM (P=0.077) and metabolizable energy (ME; P=0.051) intake. The total, ruminal, and intestinal digestibility of DM and nutrients were not affected by the inclusion of CBAS (P > 0.10). Ruminal ammonia nitrogen decreased linearly (P=0.045), while acetate concentration showed a linear increase (P=0.038), propionate was not affected (P=0.762), and butyrate showed a linear tendency to increase (P=0.086) with the inclusion of CBAS. Passage rate and DM degradation, as well as N utilization were not affected by the inclusion of CBAS (P > 0.10), except for N fecal excretion that showed a linear tendency to increase (P=0.092). Thus, we conclude that CBAS increases organic matter, crude protein, metabolizable energy, and neutral detergent fiber intake in high-concentrate diets without compromising rumen kinetics and nitrogen utilization in beef cattle. Therefore, the CBAS can be considered as an alternative roughage source in scenarios where forage silage of low quality is the fiber source.

Ewes fed high-concentrate diets containing flint corn and increasing levels of exogenous amylolytic enzyme: effects on nutrient intake and digestibility

The aim was to evaluate if the inclusion of exogenous amylolytic enzyme affect the nutrient intake and digestibility in ewes fed high-concentrate diets containing flint corn. Five Santa Inês × Dorper crossbred ewes (54.04 ± 4.5 kg and aged 8 months) were used in a 5 x 5 Latin square design. All animals were housed in individual metabolic cages for 60 days. The treatments consisted of a control diet (without amylolytic enzyme) and four inclusion levels of an amylolytic enzyme (3,000, 6,000, 9,000, and 12,000 α-amylase dextrinizing units [DU] kg-1 dry matter [DM]). The enzyme was mixed into the feed at the time of supply to the animals. Data were analyzed by ANOVA, and orthogonal polynomial contrasts were used. Nutrient intake was not influenced by amylolytic enzyme inclusion. The digestibility of DM, organic matter, neutral detergent fiber, total carbohydrates, non-fibrous carbohydrates, and gross energy showed a quadratic increase with enzyme inclusion (P&lt;0.05), with maximum values at levels of 7,600, 7,500, 6,300, 7,500, 7,400, and 7,800 DU kg-1 DM, respectively. Total digestible nutrients of diets also showed a quadratic increase, with a maximum value of 894 g kg-1 at a level of α-amylase activity of 7,786 DU kg-1 DM. The inclusion of the exogenous amylolytic enzyme from 6,300 to 7,800 DU kg-1 DM doesn’t alter nutrient intake and improves the digestibility in ewes fed high-concentrate diets.

A high-concentrate diet induces colonic inflammation and barrier damage in Hu sheep

Long-term feeding of a high-concentrate diet can induce subacute ruminal acidosis (SARA) in ruminants, which further leads to systemic inflammatory response. However, few studies have examined the effects of feeding a high-concentrate diet on the hindgut of ruminants. The purpose of this study was to investigate the effects of a high-concentrate diet on the composition of gut microbiota in colonic contents, inflammatory response, and barrier damage in the colon tissue of ruminants. A total of 12 healthy multiparous lactating Hu sheep were randomly allotted into the following 2 groups: a high-concentrate (HC) group (concentrate:forage = 7:3) and a low-concentrate (LC) group (concentrate:forage = 3:7). All sheep were fitted with ruminal fistulas. The formal feeding experiment lasted for 8 wk. After the feeding experiment, rumen fluid, portal vein blood, hepatic vein blood, colonic contents, and colon tissue samples were collected. The results showed that feeding the HC diet induced SARA in Hu sheep and significantly reduced pH in the colonic contents. The abundances of Firmicutes, Verrucomicrobiota, and Actinobacteriota decreased significantly, whereas those of Bacteroidota, Spirochaetota, and Fibrobacterota significantly increased in colonic contents. At the genus level, the relative abundances of 29 genera were significantly altered depending on the different type of diets. Analysis of the 10 bacterial genera with high relative abundance revealed that feeding the HC diet significantly reduced the abundance of UCG-005, Christensenellaceae R-7 group, UCG-010-norank, Monoglobus, [Eubacterium] coprostanoligenes group_norank, and Alistipes, whereas the abundances of Rikenellaceae RC9 gut group, Treponema, Bacteroides, and Prevotella increased. Compared with the LC group, feeding the HC diet significantly increased the concentration of LPS in rumen fluid, portal vein blood, hepatic vein blood, and colonic contents, and significantly upregulated the mRNA expression levels of proinflammatory cytokines in colon tissue, including TNF-α, IL-1β, IL-6, and IL-8, indicating the occurrence of inflammatory response in the colon tissue. In addition, the structure of colonic epithelial cells was loose, the intercellular space became larger, epithelial cells were exfoliated, and the mRNA and protein abundances of ZO-1, occludin, claudin-1, claudin-3, and claudin-4 were significantly decreased in the HC group, which was consistent with the results of immunohistochemistry. Furthermore, feeding the HC diet increased the ratios of DNA methylation and chromatin compaction in the promoter regions of occludin and claudin-1, which in turn inhibited their transcriptional expression. Therefore, the present study demonstrated that feeding an HC diet induced SARA in Hu sheep, altered the composition and structure of the microbial community in the colonic contents, induced an inflammatory response, and disrupted the intestinal mucosal barrier in the colonic tissue.

Nutrient digestibility of fibrous feedstuffs in high-concentrate diet with sodium-bicarbonate (NaHCO3) addition in rumen-fistulated Brahman bull

Ruminants are given substantial quantities of concentrate diets full of quickly fermentable carbohydrates to increase output performance; however, it can also lead to digestive disorders. This study aimed to investigate the effect of adding NaCHO3 to a high-concentrate diet on the nutrient digestibility of locally available fibrous feedstuffs in the Philippines. The experiment utilized a rumen-fistulated Brahman bull. The treatment diets were the following: Treatment 1 (T1): Untreated rice (Oryza sativa L.) straw; T2: Urea-treated rice straw; T3: Napier grass (Pennisetum purpureum Schumach); T4: Napier silage; T5: Sugar cane (Saccharum officinarum L.) tops; and T6: Cogon grass (Imperata cylindrica L.). The nylon bags containing the treatment diets were incubated in the rumen at two periods: first at a high-concentrate (70% level), and second at a high concentrate added with NaCHO3). The results showed that the nutrient digestibility of locally-available feedstuffs varies significantly (p&lt;0.05) both with and without NaHCO3. The addition of NaHCO3 in a high-fiber diet improves the digestibility of locally available fibrous feedstuffs in terms of dry matter (DM), organic matter (OM), and neutral detergent fiber (NDF). Therefore, the addition of NaHCO3 to a high-concentrate diet has the potential to positively stabilize rumen pH and enhance the nutrient digestibility of locally available fibrous feedstuffs.

Orange molasses as a new energy ingredient for feedlot lambs in Brazil.

The objectives of this experiment were to evaluate the effects of increasing levels of orange molasses in replacement of flint corn grain in high-concentrate diets on dry matter intake (DMI), average daily gain (ADG), and feed efficiency (FE) of feedlot lambs. Thirty male lambs without defined racial pattern (30.3 ± 5.3 kg of initial BW; mean ± SD) were used in a randomized complete block design with 10 blocks and 3 treatments. The treatments were defined by partial replacement of flint corn by orange molasses in the diet with 90% of concentrate and 10% of Cynodon spp. hay, as follows: 0OM-control diet without orange molasses; 20OM-20% of orange molasses replacing flint corn; and 40OM-40% of orange molasses replacing flint corn (DM basis). The experiment lasted 72 days divided into 3 subperiods, with 1 subperiod of 16 days and 2 subperiods of 28 days. Animals were weighed after a 16-h fast on days 1, 16, 44, and 72 of the experimental periods to determine the ADG and FE. The DMI, ADG, and FE showed an interaction between treatments and experimental periods. The DMI in the first period decreased linearly (P < 0.01); in the third period, there was no effect of treatments (P > 0.05) on DMI. The ADG decreased linearly (P < 0.01) in the first period as the orange molasses increased. Otherwise, in the third period, ADG increased linearly (P = 0.05) as flint corn was replacement by orange molasses. The FE showed an interaction between treatment and period (P = 0.09). The first period had a decreased linear effect; in the third period, there was a trend (P = 0.07) of increased linear effect. There was no difference between the diets regarding the final BW of the lambs. In conclusion, the orange molasses can replace up to 40% of flint corn in diets for feedlot lambs without affecting final BW. However, it is important to consider the adaptation time proved to be very important for better use of orange molasses as a source of energy in diets for lambs.

P22 Effect of chromium on fatty acid composition of the meat of lambs fed a high-concentrate diets

P22 Effect of chromium on fatty acid composition of the meat of lambs fed a high-concentrate diets

16S rRNA Sequencing Reveals the Antibacterial Effect of Omega-3 (Fish Oil) against Fibrolytic Bacteria, Altering Fermentation and Volatile Fatty Acids Profile In Vitro

Polyunsaturated fatty acids (PUFAs) constitute a significant lipid class with essential nutritional and health benefits for both animal and human health; however, their effect and interaction with the gut microbiota ecosystem are still unclear. Therefore, the present study aims to investigate the effect of fish oil (FO) on ruminal fermentation and bacterial abundance under high- and low-forage diets. Thirty-six ruminal fluid samples were allocated into two experiments. The first was on high-forage diet and included three groups: the control (basal diet with 70% forage and 30% concentrate), group 2 (basal diet + 5 mL/L FO), and group 3 (basal diet + 10 mL/L). The second experiment was on low-forage diet: the control (basal diet with 30% forage and 70% concentrate), group 2 (basal diet + 5 mL/L FO), and group 3 (basal diet + 10 mL/L). The results showed that although FO supplementation did not affect the pH level among different diets, it significantly decreased methane under a high-forage diet. In addition, regarding the fatty acids profile, FO supplementation in high-forage diet significantly decreased fatty acids in both; however, under a low-forage diet, FO groups showed significantly higher fatty acid content than the control. However, FO supplementation increased the abundance of Anaerovibirio, Selenomonas, pseudobutyrivibrio, and butyrivibrio through a high-forage diet. In contrast, the abundance of Prevotella, Rikenellaceae RC9 gut group, and Saccharofermentans was depressed with FO supplementation. Whereas under low-forage diet, FO supplementation increased Ruminobacter, Anaerovibirio, Megasphaera, Pseudobutyrivibrio, Streptococcus, Butyrivibrio, unclassified_lachnospiraceae; it also decreased Prevotella and Rikenellaceae RC9 abundance similar to the high-forage diet. Based on the KEGG pathway results, FO supplementation significantly downregulated genes mainly related to folding, sorting and degradation, environmental adaptation, cell motility, transcription, membrane transport, and signal transduction. The results revealed that FO has a depressing effect on ruminal fermentation and some bacterial population; however, this negative effect can be minimized in high-concentrate diets.

A high-concentrate diet induces mitochondrial dysfunction by activating the MAPK signaling pathway in the mammary gland of dairy cows

Subacute rumen acidosis can lead to mastitis in dairy cows. Mitochondrial dysfunction is closely related to the inflammatory response. This experiment was conducted to investigate the effects of a high-concentrate diet on mammary gland inflammation and mitochondrial damage in dairy cows. Twelve Holstein dairy cows in mid-lactation were randomly divided into 2 groups and fed a 40% concentrate (low concentrate, LC) diet or a 60% concentrate (high concentrate, HC) diet. Cows were fed individually, and the experiment lasted for 3 wk. After the experiment, mammary gland tissue, blood, and rumen fluid were collected. Compared with the LC diet, the HC diet significantly decreased rumen pH; the pH was <5.6 for more than 3 h. The HC diet also increased the concentration of LPS in the blood (7.17 ± 1.25 µg/mL vs. 12.12 ± 1.26 µg/mL), which indicated that feeding the HC diet successfully induced subacute rumen acidosis. The HC diet also increased the concentration of Ca2+ (34.80 ± 4.23 µg/g vs. 46.87 ± 7.24 µg/g) in the mammary gland and upregulated the expression of inflammatory factors IL-6 (1,128.31 ± 147.53 pg/g vs. 1,538.42 ± 241.38 pg/g), IL-1β (69.67 ± 5.86 pg/g vs. 90.13 ± 4.78 pg/g), and tumor necrosis factor-α (91.99 ± 10.43 pg/g vs. 131.75 ± 17.89 pg/g) in mammary venous blood. The HC diet also increased the activity of myeloperoxidase (0.41 ± 0.05 U/g vs. 0.71 ± 0.11 U/g) and decreased the content of ATP (0.47 ± 0.10 µg/mL vs. 0.32 ± 0.11 µg/mL) in the mammary gland. In addition, phosphorylation of JNK (1.00 ± 0.21 vs. 2.84 ± 0.75), ERK (1.00 ± 0.20 vs. 1.53 ± 0.31), and p38 (1.00 ± 0.13 vs. 1.47 ± 0.41) and protein expression of IL-6 (1.00 ± 0.22 vs. 2.21 ± 0.27) and IL-8 (1.00 ± 0.17 vs. 1.96 ± 0.26) were enhanced in cows of the HC group, indicating that the mitogen-activated protein kinase (MAPK) signaling pathway was activated. Compared with the LC diet, the HC diet reduced the protein expression of mitochondrial biogenesis-related proteins PGC-1α (1.00 ± 0.17 vs. 0.55 ± 0.12), NRF1 (1.00 ± 0.17 vs. 0.60 ± 0.10), TFAM (1.00 ± 0.10 vs. 0.73 ± 0.09), and SIRTI (1.00 ± 0.44 vs. 0.40 ± 0.10). The HC diet promoted mitochondrial fission and inhibited mitochondrial fusion by reducing protein expression of MFN1 (1.00 ± 0.31 vs. 0.49 ± 0.09), MFN2 (1.00 ± 0.19 vs. 0.69 ± 0.13), and OPA1 (1.00 ± 0.08 vs. 0.72 ± 0.07), and by increasing that of DRP1 (1.00 ± 0.09 vs. 1.39 ± 0.10), MFF (1.00 ± 0.15 vs. 1.89 ± 0.12), and TTC1/FIS1 (1.00 ± 0.08 vs. 1.76 ± 0.14), leading to mitochondrial dysfunction. The HC diet increased mitochondrial permeability by upregulating the protein expression of VDAC1 (1.00 ± 0.42 vs. 1.90 ± 0.44), ANT (1.00 ± 0.22 vs. 1.27 ± 0.17), and CYPD (1.00 ± 0.41 vs. 1.82 ± 0.43). Taken together, these results indicated that feeding the HC diet induced mitochondrial damage via the MAPK signaling pathway in the mammary gland of dairy cows.

Dietary disodium fumarate supplementation alleviates subacute ruminal acidosis (SARA)-induced liver damage by inhibiting pyroptosis via mitophagy-NLRP3 inflammasome pathway in lactating Hu sheep.

Liver damage is common in ruminants with subacute ruminal acidosis (SARA). Disodium fumarate (DF) could regulate rumen microbial community and neutralize ruminal organic acids. This study aimed to evaluate the effect of dietary DF supplementation on SARA-induced liver damage and investigate the underlying mechanism. The results showed that feeding a high-concentrate diet induced decreased rumen fluid pH and increased ruminal LPS. The rumen fluid pH in the HC group was less than 5.6 at 4 time points, indicating that SARA was successfully induced. The histopathological analysis showed that in the HC group, hemorrhage and inflammatory cell infiltration were observed in liver tissue. Using ELISA kits and biochemical analyzer, we identified that the contents of interleukin 1beta (IL-1β), interleukin 18 (IL-18), caspase-1, and the activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in hepatic vein were elevated in the HC group. However, DF supplementation increased rumen fluid pH value, decreased ruminal LPS, attenuated hemorrhage and inflammatory cell infiltration in the liver tissue, and decreased contents of IL-1β, IL-18, caspase-1, AST, and ALT in the hepatic vein. Real-time PCR and western blot analysis displayed that SARA-induced increased expression of pyroptosis-related proteins (GSDMD-NT) was attenuated in the HCDF group. Meanwhile, SARA induced increased expression of mitophagy and inflammasome-related proteins (MAP1LC3-II, PINK1, Parkin, cleaved-caspase-11, cleaved-caspase-1, NLRP3, and ASC) and elevated expression of inflammasome-related genes (NLRP3, CASP1, and ASC), which was reversed by DF supplementation. Moreover, SARA activated toll-like receptor 4 (TLR4)-nuclear factor kappa B (NF-κB) signaling pathway and inhibited the entry of forkhead box A2 (FOXA2) into the nucleus, which was reversed by DF supplementation. Collectively, our data suggest that dietary DF supplementation inhibited hepatocyte pyroptosis by regulating the mitophagy-NLRP3 inflammasome pathway and the NF-κB signaling pathway, thus alleviating SARA-induced liver damage in Hu sheep.

Measuring motivation for forage in feedlot cattle fed a high-concentrate diet using a short-term thwarting test

A thwarting test, where animals are able to interact with feed but not consume it, can be used to measure how valued the resource is. It is expected that feedlot cattle will be motivated to access additional roughage because of its potential to alleviate symptoms of ruminal acidosis caused by high-concentrate rations. The objective of this study was to measure how motivated cattle fed a high-concentrate diet are to access additional forage, when offered it freely for 8 short exposures before being prevented from consuming the resource in a thwarting test. Eighteen animals, fed a finishing ration ad-libitum, were offered a small amount of either beardless wheat hay (WH; n = 9) or their primary diet (TMR; n = 9) in a plastic bin twice daily for a maximum of 1 h over 4 d (exposures 1–8). Then on the 5th day (thwarting test), animals were given access to, but prevented from consuming their treatment diet by covering it with wire for 30 min. There was no evidence of treatment differences detected during the thwarting test. This may indicate there was adequate roughage in the primary diet to satisfy motivation for thwarted WH. Animals were quick to approach the treatments (average latency less than 30 s) during the test, possibly indicating motivation to access both. Unlike the thwarting test, behavioural responses to the treatments differed in the exposures, when cattle showed more interest in the TMR than the WH. Interacting with the bin by moving it with their muzzles was observed more often for TMR animals than WH animals in exposures 7 and 8 (P = 0.07 and 0.04, respectively). There was no evidence that latency to approach the bin differed by treatment or exposure (P > 0.1). These findings provide some evidence in support of the theory that animals will seek out a high-energy diet such as the TMR, because it is more calorically-dense, and likely more palatable. However, these data do not support the hypothesis that finishing cattle will be more motivated to access WH than TMR when thwarted from doing so.

Blend of Cinnamaldehyde, Eugenol, and Capsicum Oleoresin Improved Rumen Health of Lambs Fed High-Concentrate Diet as Revealed by Fermentation Characteristics, Epithelial Gene Expression, and Bacterial Community.

We investigated the effects of CEC on the fermentation characteristics, epithelial gene expression, and bacterial community in the rumen of lambs fed a high-concentrate diet. Twenty-four 3-month-old female crossbred lambs with an initial body weight of 30.37 ± 0.57 kg were randomly allocated to consume a diet supplemented with 80 mg/kg CEC (CEC) or not (CON). The experiment consisted of a 14 d adaptation period and a 60 d data collection period. Compared with the CON group, the CEC group had higher ADG, epithelial cell thickness, ruminal butyrate proportion, and lower ammonia nitrogen concentration. Increases in the mRNA expression of Occludin and Claudin-4, as well as decreases in the mRNA expression of apoptotic protease activating factor-1 (Apaf-1), cytochrome c (Cyt-C), Caspase-8, Caspase-9, Caspase-3, Caspase-7, and toll-like receptor 4 (TLR4), were observed in the CEC group. Moreover, CEC treatment also decreased the concentration of IL-1β, IL-12, and TNF-α. Supplementation with CEC altered the structure and composition of the rumen bacterial community, which was indicated by the increased relative abundances of Firmicutes, Synergistota, Rikenellaceae_RC9_gut_group, Olsenella, Schwartzia, Erysipelotrichaceae_UCG-002, Lachnospiraceae_NK3A20_group, Acetitomaculum, [Eubacterium]_ruminantium_group, Prevotellaceae_UCG-004, Christensenellaceae_R-7_group, Sphaerochaeta, Pyramidobacter, and [Eubacterium]_eligens_group, and the decreased relative abundances of Acidobacteriota, Chloroflexi, Gemmatimonadota, and MND1. Furthermore, Spearman correlation analysis revealed that the altered rumen bacteria were closely correlated with rumen health-related indices. Dietary CEC supplementation improved growth performance, reduced inflammation and apoptosis, protected barrier function, and modulated the bacterial community of lambs fed a high-concentrate diet.

High-concentrate diet elevates histone lactylation mediated by p300/CBP through the upregulation of lactic acid and induces an inflammatory response in mammary gland of dairy cows

High-concentrate diet can cause metabolic diseases, such as subacute ruminal acidosis (SARA), and secondary mastitis. To investigate the effect of SARA induced by high-concentrate diet on the lysine lactylation (Kla) and inflammatory responses in the mammary gland of dairy cows and the mechanism between them, we selected twelve mid-lactation Holstein cows with similar body conditions for modelling. They were randomly divided into two groups, fed a low-concentrate diet (LC) and a high-concentrate diet (HC) for 21 days. Our results showed that high-concentrate diet feeding significantly reduced ruminal pH, and the pH was below 5.6 for more than 3 h per day, indicating successful induction of the SARA model. Lactic acid concentrations in mammary gland and plasma were higher in the HC group than that in the LC group. HC diet feeding significantly up-regulated the expression levels of the Pan Kla, H3K18la, p300/CBP and monocarboxylate transporter 1 (MCT1) in the mammary gland. In addition, the mRNA expression levels of inflammatory factors were significantly regulated, including IL-1β, IL-1α, IL-6, IL-8, SAA3, and TNF-α, while the anti-inflammatory factor IL-10 was down-regulated. The mammary gland of HC group was structurally disorganized with incomplete glandular vesicles, with a large number of detached mammary epithelial cells and inflammatory cells infiltration. The up-regulation of TLR4, TNF-α, p-p65, and p-IκBα indicated that the TLR4/NF-κB signaling pathway was activated. In conclusion, this study found that HC diet feeding can induce SARA and increase the concentration of lactic acid in mammary gland and plasma. Then, lactic acid could be transported into cells by MCT1 and up-regulate the expression level of histone lactylation mediated by p300/CBP, and subsequently promote the activation of TLR4/NF-κB signaling pathway, ultimately causing inflammatory responses in the mammary gland.

Effects of a High-Concentrate Diet on the Blood Parameters and Liver Transcriptome of Goats.

The objective of this study was to determine the effect of high-concentrate diets on the blood parameters and liver transcriptome of goats. Eighteen goats were allocated into three dietary treatments: the high level of concentrate (HC) group, the medium level of concentrate (MC) group, and the low level of concentrate (LC) group. The blood parameters and pathological damage of the gastrointestinal tract and liver tissues were measured. In hepatic portal vein blood, HC showed higher LPS, VFAs, and LA; in jugular vein blood, no significant differences in LPS, VFAs, and LA were recorded among groups (p > 0.05). Compared to the LC and MC groups, the HC group showed significantly increased interleukin (IL)-1β, IL-10, TNF-α, and diamine oxidase in jugular vein blood (p < 0.05). Liver transcriptome analysis discovered a total of 1269 differentially expressed genes (DEGs) among the three groups and most of them came from the HC vs. LC group. There were 333 DEGs up-regulated and 608 down-regulated in the HC group compared to the LC group. The gene ontology enrichment analysis showed that these DEGs were mainly focused on the regulation of triacylglycerol catabolism, lipoprotein particle remodeling, and cholesterol transport. The Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that the liver of the HC group enhanced the metabolism of nutrients such as VFAs through the activation of AMPK and other signaling pathways and enhanced the clearance and detoxification of LPS by activating the toll-like receptor signaling pathway. A high-concentrate diet (HCD) can significantly promote the digestion of nutrients; the liver enhances the adaptability of goats to an HCD by regulating the expression of genes involved in nutrient metabolism and toxin clearance.

8 Differential Growth Performance in Conventionally and Artificially Raised Lambs Fed High-Concentrate and High-Forage Post-Weaning Diets

Abstract Artificial rearing of lambs on milk replacer presents management challenges for producers and can impact performance. The objective of this experiment was to evaluate effects of pre-weaning management on adaptation to post-weaning finishing diets. We hypothesized that lambs fed a high-concentrate (HC) diet would exhibit more efficient body weight (BW) gain than lambs fed a high-forage diet (HF) regardless of pre-weaning management. Thirty-two Polypay conventionally raised (CR; n = 10 rams, 6 ewes) or artificially raised (AR; n =10 rams, 6 ewes) lambs (age: 84.0 ± 0.8 d) were blocked by sex and BW and randomly assigned to either a HC (85:15 concentrate: forage) or HF (50:50 concentrate:forage) finishing diet (n = 8 CR and AR lambs diet-1). Individually housed lambs were fed ad libitum and remained on feed through a target finishing weight of 59.0 or 54.4 kg for rams and ewes, respectively. Feed intake and BW gain were measured at 7-day intervals. Data were analyzed by PROC GLM in SAS (v. 9.4, SAS Inst. Inc., Cary, NC). Initial BW for CR lambs (39.0 ±.9 kg) was greater than for AR (32.9 ± 0.5 kg; P &amp;lt; 0.01), but there was no difference between diets (P = 0.72) or pre-weaning by diet interaction (P = 0.54). Time on feed and average daily gain (ADG) did not differ between diets for CR (time on feed: 48.1 ± 2.8 d; ADG: 206.9 ±1.4 g∙d-1; P ≥ 0.22). In contrast, post-weaning diet did impact time on feed for AR lambs, with longer time on feed for HF (68.9 ± 2.5 d) than HC (56.2 ± 2.4 d; P &amp;lt; 0.01). The ADG was also numerically greater for HC (424 ±9.8 g) than HF (370 ± 24.0 g) for AR lambs (P = 0.11). Dry matter intake (DMI) was less for CR lambs fed HC (35.16 ±.65 g kg BW-1∙d-1) than HF (41.32 ± 0.69 g∙kg BW-1∙d-1,P &amp;lt; 0.01) but did not differ between diets for AR lambs (40.58 ±.35 g kg BW-1∙d-1; P = 0.99). The decreased DMI in CR lambs fed HC resulted in greater feed efficiency (0.26 ± 0.02) compared with lambs fed HF (0.21 ± 0.01; P = 0.03). Feed efficiency did not, however, differ by diet for AR lambs (HC: 0.27 ± 0.02; P = 0.64). Results of this study suggest that CR lambs were better able to adapt to a HF finishing diet than AR lambs. Additionally, CR lambs exhibited superior feed utilization when fed HC in comparison to HF, but this response was not found for AR lambs. Overall, these results demonstrate differential adaptation to HC vs. HF finishing diets in response to pre-weaning management.

Coordinated response of milk bacterial and metabolic profiles to subacute ruminal acidosis in lactating dairy cows

BackgroundBovine milk is an important source of nutrition for human consumption, and its quality is closely associated with the microbiota and metabolites in it. But there is limited knowledge about the milk microbiome and metabolome in cows with subacute ruminal acidosis.MethodsEight ruminally cannulated Holstein cows in mid lactation were selected for a 3-week experiment. The cows were randomly allocated into 2 groups, fed either a conventional diet (CON; 40% concentrate; dry matter basis) or a high-concentrate diet (HC; 60% concentrate; dry matter basis).ResultsThe results showed that there was a decreased milk fat percentage in the HC group compared to the CON group. The amplicon sequencing results indicated that the alpha diversity indices were not affected by the HC feeding. At the phylum level, the milk bacteria were dominated by Proteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes both in the CON and HC groups. At the genus level, the HC cows displayed an improved proportion of Labrys (P = 0.015) compared with the CON cows. Results of both the principal components analysis and partial least squares of discriminant analysis of milk metabolome revealed that samples of the CON and HC groups clustered separately. A total of 31 differential metabolites were identified between the two groups. Of these, the levels of 11 metabolites decreased (α-linolenic acid, prostaglandin E2, L-lactic acid, L-malic acid, 3-hydroxysebacic acid, succinyladenosine, guanosine, pyridoxal, L-glutamic acid, hippuric acid, and trigonelline), whereas the levels of the other 20 metabolites increased in the HC group with respect to the CON group (P < 0.05).ConclusionThese results suggested that subacute ruminal acidosis less impacted the diversity and composition of milk microbiota, but altered the milk metabolic profiles, which led to the decline of the milk quality.

A high-concentrate diet induces inflammatory injury via regulating Ca2+/CaMKKβ-mediated autophagy in mammary gland tissue of dairy cows.

Calmodulin-dependent protein kinase β (CaMKKβ) is closely related to Ca2+ concentration. An increase in Ca2+ concentration in the cytoplasm activates CaMKKβ, and activated CaMKKβ affects the activities of AMPK and mTOR and induces autophagy. A high-concentrate diet leads to Ca2+ disorder in mammary gland tissue. Therefore, this study mainly investigated the induction of mammary gland tissue autophagy by a high-concentrate diet and the specific mechanism of lipopolysaccharide (LPS)-induced autophagy in bovine mammary epithelial cells (BMECs). Twelve mid-lactation Holstein dairy cows were fed with a 40% concentrate diet (LC) and a 60% concentrate diet (HC) for 3 weeks. At the end of the trial, rumen fluid, lacteal vein blood, and mammary gland tissue were collected. The results showed that the HC diet significantly decreased rumen fluid pH, with a pH lower than 5.6 for more than 3 h, indicating successfully induction of subacute rumen acidosis (SARA). The mechanism of LPS-induced autophagy in BMECs was studied in vitro. First, the cells were divided into a Ctrl group and LPS group to study the effects of LPS on the concentration of Ca2+ and autophagy in BMECs. Then, cells were pretreated with an AMPK inhibitor (compound C) or CaMKKβ inhibitor (STO-609) to investigate whether the CaMKKβ-AMPK signaling pathway is involved in LPS-induced BMEC autophagy. The HC diet increased the concentration of Ca2+ in mammary gland tissue and pro-inflammatory factors in plasma. The HC diet also significantly increased the expression of CaMKKβ, AMPK, and autophagy-related proteins, resulting in mammary gland tissue injury. In vitro cell experiments showed that LPS increased intracellular Ca2+ concentration and upregulated protein expression of CaMKKβ, AMPK, and autophagy-related proteins. Compound C pretreatment decreased the expression of proteins related to autophagy and inflammation. In addition, STO-609 pretreatment not only reversed LPS-induced BMECs autophagy but also inhibited the protein expression of AMPK, thereby alleviating the inflammatory response in BMECs. These results suggest that inhibition of the Ca2+/CaMKKβ-AMPK signaling pathway reduces LPS-induced autophagy, thereby alleviating inflammatory injury of BMECs. Therefore, SARA may increase the expression of CaMKKβ by increasing Ca2+ levels and activate autophagy through the AMPK signaling pathway, thereby inducing inflammatory injury in mammary gland tissue of dairy cows.

Comparison of the Effect of using Chemical Buffer and Acid-Consuming Bacteria on Digestibility and Fermentation, Growth Performance and Meat Quality of Lambs Fed with High Concentrate Diets

Comparison of the Effect of using Chemical Buffer and Acid-Consuming Bacteria on Digestibility and Fermentation, Growth Performance and Meat Quality of Lambs Fed with High Concentrate Diets