HM Diets Research Articles

Dietary Methionine via Dose-Dependent Inhibition of Short-Chain Fatty Acid Production Capacity Contributed to a Potential Risk of Cognitive Dysfunction in Mice.

High-methionine diets induce impaired learning and memory function, dementia-like neurodegeneration, and Alzheimer's disease, while low-methionine diets improve learning and memory function. We speculated that variations in intestinal microbiota may mediate these diametrically opposed effects; thus, this study aimed to verify this hypothesis. The ICR mice were fed either a low-methionine diet (LM, 0.17% methionine), normal methionine diet (NM, 0.86% methionine), or high-methionine diet (HM, 2.58% methionine) for 11 weeks. We found that HM diets damaged nonspatial recognition memory, working memory, and hippocampus-dependent spatial memory and induced anxiety-like behaviors in mice. LM diets improved nonspatial recognition memory and hippocampus-dependent spatial memory and ameliorated anxiety-like behavior, but the differences did not reach a significant level. Moreover, HM diets significantly decreased the abundance of putative short-chain fatty acid (SCFA)-producing bacteria (Roseburia, Blautia, Faecalibaculum, and Bifidobacterium) and serotonin-producing bacteria (Turicibacter) and significantly increased the abundance of proinflammatory bacteria Escherichia-Shigella. Of note, LM diets reversed the results. Consequently, the SCFA and serotonin levels were significantly decreased with HM diets and significantly increased with LM diets. Furthermore, HM diets induced hippocampal oxidative stress and inflammation and selectively downregulated the hippocampus-dependent memory-related gene expression, whereas LM diets selectively upregulated the hippocampus-dependent memory-related gene expression. In conclusion, dietary methionine via dose-dependent inhibition of SCFA production capacity contributed to a potential risk of cognitive dysfunction in mice.

Effects of dietary methionine on growth performance, meat quality and oxidative status of breast muscle in fast- and slow-growing broilers

This experiment was conducted to investigate the effects of dietary methionine (Met) on growth performance, carcass traits, meat quality and oxidative status of breast muscle in fast- (Arbor Acres, AA) and slow- (Partridge Shank, PS) growing broilers from 1 to 42 d of age. The broilers were divided into a 2 × 3 factorial design with 6 replicates per treatment. Diets were formulated to contain low (LM, 0.35 and 0.31% during 1 to 21 and 22 to 42 d), adequate (AM, 0.50 and 0.44%) and high (HM, 0.65 and 0.57%) Met, respectively. The main effects showed that the AA broilers had superior (P < 0.05) growth performance and carcass traits compared with those of the PS broilers. The breast muscle of the AA broilers had lower (P < 0.05) drip loss and malondialdehyde (MDA) content but higher (P < 0.05) cooking loss and glutathione peroxidase (GPX) activity than that of the PS broilers. Compared with the LM diets, the AM and HM diets increased (P < 0.05) 42-d BW, ADG, eviscerated yield and breast muscle yield only in the AA broilers. The AA broilers fed the HM diets had higher (P < 0.05) pH but lower (P < 0.05) L*, cooking loss and ether extract content in breast muscle than those fed the LM diets. Compared with the LM diets, the HM diets resulted in strain-dependent changes (P < 0.05) in muscle oxidative status, with total antioxidant capacity (T-AOC) increased in the AA broilers, GPX activity increased and MDA content decreased in the PS broilers, and superoxide dismutase (SOD) activity increased in both strains of broilers. No differences were observed between the AM and HM diets except for T-AOC in breast muscle. In conclusion, the LM treatment negatively affected broiler growth performance, carcass traits, meat quality and oxidative status of breast muscle in a strain-dependent manner, particularly in the AA broilers, whereas the HM treatment had limited effects compared to the AM treatment.

Effects of dietary methionine on breast muscle growth, myogenic gene expression and IGF-I signaling in fast- and slow-growing broilers

This study investigated the responses of fast- (FG) and slow- (SG) growing broilers to dietary methionine (Met) status. The broilers were subjected to low (LM, 0.38 and 0.28 g/100 g), adequate (AM, 0.51 and 0.42 g/100 g) and high (HM, 0.65 and 0.52 g/100 g) Met during 1–21 and 22–42 d, respectively. Compared with the LM diets, the AM and HM diets increased body weight gain only in the FG broilers. The HM diets increased breast muscle yield only in the FG broilers, although insulin-like growth factor-I (IGF-I) concentration was increased in both strains of broilers. The HM diets increased mRNA levels of myogenic regulatory factors (MRF4, Myf5) and myocyte enhancer factor 2 (MEF2A and MEF2B) in the FG broilers, and increased MEF2A and decreased myostatin mRNA level in the SG broilers. Extracellular signal-regulated kinase (ERK) phosphorylation of breast muscle was increased by the HM diets in both strains of broilers, but mechanistic target of rapamycin (mTOR) phosphorylation was increased by the AM and HM diets only in the FG broilers. These results reflect a strain difference in broiler growth and underlying mechanism in response to dietary Met.

Black soldier fly (Hermetia illucens) pre-pupae meal as a fish meal replacement in diets for European seabass (Dicentrarchus labrax)

A feeding trial was carried out to assess the effect of partially replacing fish meal (FM) by Black soldier fly pre-pupae meal (HM) in diets for European seabass Dicentrarchus labrax juveniles. A FM-based diet was used as a control and three other diets were formulated to include 6.5%, 13%, and 19.5% of HM, replacing 15%, 30% and 45% of FM respectively. Each diet was fed to triplicate groups of fish (initial weight: 50g) for 62days.At the end of the trial, there were no differences among groups in growth performance or feed utilization. Plasma metabolic profiles also remained unaffected, except that plasma cholesterol was reduced with dietary HM inclusion. The apparent digestibility coefficients (ADC) of protein, lipids, dry matter, organic matter, and energy were generally high, and not affected by the dietary treatment. The ADC of arginine, histidine, and valine were higher in HM diets when compared to the control. Amylase and protease activities were not affected by dietary HM, while lipase activity was lower in HM 6.5 diets than in the control and HM 19.5 diets.In conclusion, up to 19.5% of HM, corresponding to 22.5% of total dietary protein, may successfully replace FM in diets for juvenile European seabass, without adverse effects on growth performance, feed utilization or digestibility.

고지방식이로 유도한 지방간 마우스에서 기장 첨가식이가 지방간 및 인슐린 저항성에 미치는 영향

비알코올성 지방간은 인슐린저항성을 근간으로 하는 대사증후군의 원인으로 생각되고 있으며 최근 그 발병율이 증가하고 있다. 본 연구진은 기장 열수추출물을 식이에 첨가하여 고지방식에 의해 인위적으로 지방간을 유도한 마우스에게 섭취시킨 후 혈청 내 생물학적 수치와 간조직 검사를 통하여 비알코올성 지방간 억제 효과를 검토하였다. 그 결과, 식이섭취량은 차이가 없었으나 간조직 무게가 1% 및 2% 기장 열수추출물 첨가식이군에서 유의적으로 감소하였고(p<0.05) 간조직 내 지방 축적이 유의적으로 감소하였음을 확인하였다. 또한 기장 열수추출물 첨가식이군의 경우 고지방식 대조군에 비해 혈청 중성지방 및 총 콜레스테롤이 감소하였고(p<0.05), HDL과 HDL-/총 콜레스테롤의 비율이 유의적으로 증가하여(p<0.05) 혈액의 지질 조성이 개선되었음을 알 수 있었다. HOMA-IR 및 포도당 내성 검사 결과 2% 기장 열수추출물 첨가군의 경우 이들 모두 유의적으로 감소하여 고지방식에 의한 인슐린 저항성 및 당흡수 부전을 기장열수추출물이 완화시켰다(p<0.05). 한편 간조직에서 지방산 대사와 관련된 인자들의 유전자 발현을 측정한 결과 지방산 합성에 관여하는 L-FABP와 SCD1은 2% 기장 열수추출물 섭취군에서 유의적으로 감소하였고(p<0.05) 지방산 산화와 관련된 PPARα는 1% 및 2% 기장 열수추출물 섭취군에서 모두 유의적으로 증가하였다(p<0.05). 이상의 혈청 및 조직의 생물학적 수치와 간조직 검사 결과를 미루어 볼 때 기장 열수추출물 첨가 식이는 고지방식이에 의해 유도된 마우스의 비알코올성 지방간 치유 혹은 예방에 긍정적으로 기여할 수 있음을 시사해 준다.

Influence of cold-pressed canola, brewers grains and hominy meal as dietary supplements suitable for reducing enteric methane emissions from lactating dairy cows

There are limited data in the literature concerning in vivo effects of dietary fat supplementation on enteric CH4 emissions from lactating dairy cows. The purpose of this experiment was to evaluate four dietary treatments designated as control (CON), brewers grains (BG), hominy meal and cold-pressed canola (HCC) and hominy meal only (HM) for their effects on CH4 emissions and milk production. Sixteen late lactation Holstein cows were used in pairs, in a double 4×4 Latin square experiment with the four dietary treatments fed as total mixed rations over 24d treatment periods. All diets contained ∼600gforage/kg dry matter (DM; 5kgDM of alfalfa hay and 7kgDM of perennial ryegrass silage/day). The CON diet contained 303g/kgDM of cracked wheat grain and 70g/kgDM of solvent extracted canola meal and the CON diet was formulated to contain ∼26g total fat/kgDM. For the BG, HCC and HM diets, part of the cracked wheat and solvent extracted canola was substituted with the designated fat supplement so that the resulting diets contained 51, 52 and 65g total fat/kgDM respectively. Fat supplementation did not influence DM intake and there were only small (P<0.05) positive effects on milk yield and negative effects on concentrations of milk fat and milk protein. The HM diet reduced (P<0.05) CH4 emissions when expressed either as gCH4/cow/d, gCH4/kgDM intake, or gCH4/L milk. The BG diet also (P<0.05) reduced CH4 emissions when expressed as gCH4/cow/d or gCH4/L milk, while the HCC diet decreased CH4 emissions in terms of gCH4/L milk. Combining data from the fat supplemented diets enabled comparison of CH4 emissions from the CON diet with CH4 emissions from the fat supplemented diets. Fat supplementation reduced (P<0.05) CH4 emissions: 500, 462gCH4/cow/d; 25.0, 23.2gCH4/kgDM intake and 23.3, 20.5gCH4/L milk for the CON and fat supplemented groups respectively. Similarly, by combining data from all fat supplemented groups, regression analysis revealed that fat supplementation reduced CH4 emissions for at least 7wk. Combining results of this investigation with data from the literature, we conclude that for each increase of 10g/kgDM in dietary lipid concentration, enteric emissions are reduced by 0.79gCH4/kgDM intake or ∼3.5% thereby allowing estimation of the magnitude of enteric CH4 abatement based on dietary fat supplementation.This article is part of the special issue entitled: Greenhouse Gases in Animal Agriculture – Finding a Balance between Food and Emissions, Guest Edited by T.A. McAllister, Section Guest Editors; K.A. Beauchemin, X. Hao, S. McGinn and Editor for Animal Feed Science and Technology, P.H. Robinson.

Successful Manipulation of the Quality and Quantity of Fat and Carbohydrate Consumed by Free-Living Individuals Using a Food Exchange Model ,

Our objective in this study was to develop and implement an effective intervention strategy to manipulate the amount and composition of dietary fat and carbohydrate (CHO) in free-living individuals in the RISCK study. The study was a randomized, controlled dietary intervention study that was conducted in 720 participants identified as higher risk for or with metabolic syndrome. All followed a 4-wk run-in reference diet [high saturated fatty acids (SF)/high glycemic index (GI)]. Volunteers were randomized to continue this diet for a further 24 wk or to 1 of 4 isoenergetic prescriptions [high monounsaturated fatty acids (MUFA)/high GI; high MUFA/low GI; low fat (LF)/high GI; and LF/low GI]. We developed a food exchange model to implement each diet. Dietary records and plasma phospholipid fatty acids were used to assess the effectiveness of the intervention strategy. Reported fat intake from the LF diets was significantly reduced to 28% of energy (%E) compared with 38%E from the HM and LF diets. SF intake was successfully decreased in the HM and LF diets to ≤10%E compared with 17%E in the reference diet (P = 0.001). Dietary MUFA in the HM diets was ∼17%E, significantly higher than in the reference (12%E) and LF diets (10%E) (P = 0.001). Changes in plasma phospholipid fatty acids provided further evidence for the successful manipulation of fat intake. The GI of the HGI and LGI arms differed by ∼9 points (P = 0.001). The food exchange model provided an effective dietary strategy for the design and implementation across multiple sites of 5 experimental diets with specific targets for the proportion of fat and CHO.

Effect of dietary medicinal herbs on lipid metabolism and stress recovery in red sea bream Pagrus major

The effect of dietary medicinal herbs on lipid metabolism and stress recovery was investigated in red sea bream Pagrus major. Fish (mean body weight 24.0 ± 0.2 g) were fed on test fish meal diets supplemented with either Massa Medicata (Mm), Crataegi Fructus (Cf), Artemisia capillaries (Ac), or Cnidium officinale (Co), or with a mixture of the four herbs (HM) for 12 weeks. A control group was fed a diet without herbs in the same manner. A high survival rate was observed in the herbal diet groups. The final mean body weight, feed efficiency, protein efficiency ratio, and apparent protein and lipid retention in the Ac, Co, and HM groups were higher than those in the control and Mm groups. Final carcass, hepatic lipid and triglyceride contents, and plasma triglyceride and nonesterified fatty acid levels were lower in the Ac, Co, and HM groups compared to those of control and Mm groups. However, final hepatic phospholipid, plasma phospholipid, and high density lipoprotein cholesterol levels were higher in the Ac, Co, and HM diets groups than in the control and Mm groups. The Cf, Co, Ac, and HM groups showed faster recovery time in the 2-phenoxyethanol anesthesia test and a higher recovery rate in the 10-min air exposure test than those of the control and Mm groups. Moreover, the Cf, Ac, Co, and HM diet groups had a significantly lower plasma cortisol level than the control and Mm diet group, but the glucose level in the herbal diet groups was higher than that in the control group after a 1-h air exposure. These results indicate that the addition of medicinal herbs to the fish diet improved lipid utilization and stress recovery in red sea bream.

Effect of partly replacing cottonseed cake with Mucuna spp. (var. Ghana) hay on feed intake and digestibility, milk yield and milk composition of zebu cows

The effect of partly replacing cottonseed cake with Mucuna hay (Mucuna spp. var. Ghana) on feed intake, digestibility and milk production of dairy cows was studied using six Zebu cows randomly assigned to three dietary treatments in a replicated Latin square design. All cows were fed hay from natural pastures ad libitum and 1.1 kg molasses as a basal diet, which was supplemented with: (1) 2 kg cottonseed cake (control diet), (2) 1.5 kg cottonseed cake and 1.2 kg Mucuna hay (low Mucuna, LM), and (3) 1.0 kg cottonseed cake and 3.3 kg Mucuna hay (high Mucuna, HM). Dry matter (DM) and crude protein (CP) intake were similar for all the diets. The addition of Mucuna significantly increased DM and organic matter digestibility, whereas CP, acid detergent fibre and neutral detergent fibre digestibility were similar among the diets. The treatments had no effect on daily milk yield (3.38, 3.43 and 3.38 kg milk) or milk composition (41.1, 43.7 and 42.7 g fat/kg milk; 35.1, 36.4 and 35.9 g protein/kg milk; and 46.1, 45.8 and 45.3 g lactose/kg milk, respectively, for cows fed control, LM and HM diets). The treatments had no significant effect on live weight changes. The results showed that replacing 50% of the cottonseed cake with Mucuna hay had no negative effects on feed intake and digestibility, milk yield or milk composition.

Carry-over effects of early-life supplementary methionine on lymphoid organs and immune responses in egg-laying strain chickens

The carry-over effects of supplementing egg-laying strain chickens with methionine until 4 weeks of age on growth, lymphoid organs and immune responses were assessed in a 12-week study. A peanut meal-based diet (2.8 g methionine/kg) supplemented with 0 g (control), 2 g (LM) or 4 g (HM) dl-methionine/kg, was offered to day-old ISA Brown male chicks for 4 weeks, then all birds were offered a commercial pullet grower feed (2.5 g methionine/kg) for another 8 weeks. The methionine contents of the control, LM and HM diets are equivalent to 100, 171 and 243%, respectively, of the NRC-recommended level. Growth rates, feed intake and feed efficiency were improved (P<0.05) by additional methionine during the supplementary period, and the effects on growth rates and feed intake were still significant (P<0.05) during Weeks 4–8. At Week 4, thymus weight relative to bodyweight (BW) was higher (P<0.05) in birds given HM than in control birds, and bursa weight relative to BW was higher (P<0.05) in chickens given LM than in control or HM-fed birds. HM-fed chickens tended (P=0.06) to have a higher relative bursa weight than control birds at Week 4, and the difference became significant at Week 8 (P<0.05). Neither total serum primary antibody levels against sheep erythrocytes nor cutaneous toe-web responses to phytohaemagglutinin (PHA) were affected by supplementary methionine at any time (P>0.05). It is concluded that early-life dietary methionine offered beyond the NRC-recommended level had minimal effects on humoral or cell-mediated immunity, but its stimulatory effects on growth rates and feed intake, and development of the bursa persisted for a short period into a later stage of the chicken's life.

α-Glucosidase inhibitors prevent diet-induced increases in intestinal sugar transport in diabetic mice

The recommended diet for diabetes mellitus is rich in complex carbohydrates. We have previously shown that high carbohydrate levels in the intestinal lumen induce adaptive increases in sugar absorption which in turn exacerbate postprandial hyperglycemia in diabetic mice. α-Glucosidase inhibitors (AGIs) hinder digestion of complex carbohydrates and therefore alleviate postprandial glycemic excursions. In this study, we tested the hypothesis that AGIs prevent the carbohydrate-induced upregulation of intestinal glucose and fructose transport in diabetes. Streptozotocin-diabetic mice were fed the following isocaloric diets: high carbohydrate (H), H plus acarbose (HA), H plus deoxy-nojirimycin (HD), and low carbohydrate (L), then nutrient uptakes were determined after 2 and 4 weeks. Body weight, intestinal weight, and length were independent of diet. Fasting and postprandial blood glucose levels were lower in HA and HD than in H mice. Uptakes of d-glucose and d-fructose were 2 to 3 times greater in H than in L mice, but HA and HM diets gradually reduced d-glucose uptakes to rates similar to L mice. Only HA diets reduced d-fructose uptake. Intestinal proline, aspartate, and glutamine uptakes were each greater in L than in H, HA, and HD mice. α-Glucosidase inhibitors did not alter intestinal permeability and amino acid transport rates. α-Glucosidase inhibitor–inhibitable increases in total intestinal absorptive capacity for sugars were due to carbohydrate-induced increases in V max of glucose transport. Clearly, one potential mechanism by which AGIs blunt postprandial glycemic excursions and lower fasting blood glucose concentrations in individuals consuming carbohydrate-containing diets is by preventing carbohydrate-induced increases in intestinal sugar transport.

Dietary Fat and Phospholipase A2 Activity of Sprague-Dawley Rat Large Intestine

The present studies were conducted to examine the effect of dietary lipid content and composition [(n-6) vs. (n-3) fatty acids] on the activity of mucosal phospholipase (PL)A2 of the large intestinal tract of rats. Three segments of the large intestinal tract were examined: cecum, proximal colon and distal colon. Weanling male Sprague-Dawley rats were fed diets containing either 5% (LS) or 16% safflower (HS) or 14% menhaden oil plus 2% safflower oil (HM) for 3 wk with the oil replacing starch in the HS and HM diets on a weight basis. The lipid extracts of microsomal fractions from mucosal scrapings were examined for phospholipid and cholesterol content and fatty acid composition. Phospholipase A2 was assayed using a fluorescent substrate. Rats fed the high fat diets had lower PLA2 specific activities. The (n-3) or (n-6) fatty acid enrichment of the membranes had no effect of the activity of the enzyme. The activity of the enzyme decreased aborally from the cecum to the distal colon; the proximal colon had an intermediate specific activity.

Effects of molybdenum and sulfur on digestion by steers.

Effects of Mo and S on the digestion of dietary DM, ash, OM, NDF, CP, and nonprotein OM were evaluated using four Holstein steers, each with cannulas in the rumen, proximal duodenum (PD), and terminal ileum (TI). Steers were continuously fed diets with high (13.3 mg/kg DM) and low (1.8 mg/kg DM) Mo (HM and LM, respectively) and high (3.9 g/kg DM) and low (1.3 g/kg DM) S (HS and LS, respectively) as combinations LMLS, LMHS, HMLS, and HMHS in a 4 x 4 Latin square design. Daily flows of dietary components at the PD and TI and as fecal excretion were estimated using dysprosium as an inert marker. With HM diets, the balance between absorption and endogenous input in the stomach was such that there was a lower (P less than .10) net (intake minus duodenal flow) output of mineral from the stomach. A lower (P less than .10) net output of diaminopimelic acid as an indicator of bacterial CP and DM was associated with a lower (P less than .10) net output of CP from the stomach of steers fed HM diets. This lower net output of CP from the stomach, coupled with no effect (P greater than .10) of Mo on CP in the small intestine, indicated that less CP was absorbed from the small intestine. Supplemental Mo in association with S appeared to prevent (P less than .10) an apparent higher net output of methionine from the stomach when supplemental S alone was in the diet. Effects of supplemental S were minor compared with those of supplemental Mo. Dietary Mo had negative effects on ash as an indicator of mineral balance in the stomach of steers and on the output of CP as bacterial CP and of DM of bacterial origin from the stomach of steers.