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1.
The objective of this study was to identify qualitative and quantitative differences in microbial populations of adult cats fed diets containing different protein concentrations. Following a 4 week baseline period, eight healthy adult domestic short‐hair queens (>1‐year‐old) were randomly allotted to a moderate‐protein (MP; n = 4) or high‐protein (HP; n = 4) diet for 8 weeks. Fresh faecal samples were collected after baseline and 8 weeks on treatment and stored at ?80 °C. Following DNA extraction, samples were analyzed using denaturing gradient gel electrophoresis to distinguish qualitative changes between diets. Quantitative polymerase chain reaction was used to measure E. coli, Bifidobacterium, Clostridium perfringens, and Lactobacillus populations. Compared to baseline, cats fed MP had a bacterial similarity index of 66.7% as opposed to 40.6% similarity for those fed HP, exhibiting marked changes in intestinal bacteria of cats fed HP. Bifidobacterium populations were greater (p < 0.05) in cats fed MP versus HP (9.44 vs. 5.63 CFU/g). Clostridium perfringens populations were greater (p < 0.05) in cats fed HP than MP (12.39 vs. 10.83 CFU/g). In this experiment, a high‐protein diet resulted in a dramatic shift in microbial populations. Decreased Bifidobacterium population in cats fed HP may justify prebiotic supplementation for such diets.  相似文献   

2.
The effects of the administration of four Lactobacillus strains as probiotics on the constitution of microbial populations in the intestine of pigs were investigated by using a litter of pigs. The experimental group was fed a diet blended with the freeze‐dried powder containing lactobacilli at a concentration of 0.2% (W/W). After 4 weeks of probiotics administration, the total viable count of anaerobes in the feces was not significantly different between the pigs fed a diet supplemented with probiotics and the pigs given the non‐supplemented diet. However, viable counts of eubacteria were significantly higher (P < 0.01) in the feces of pigs fed a diet supplemented with probiotics than in the pigs given the non‐supplemented diet. Conversely, viable counts of clostridia were significantly lower (P < 0.01) in the feces of pigs fed a diet supplemented with probiotics than the pigs given the non‐supplemented diet. The total volatile fatty acid concentrations in the feces of pigs that were given a diet supplemented with probiotics were significantly lower (P < 0.05) than those given the non‐supplemented diet. Further, the molar proportion of n‐butyric acids in the feces of pigs that were given a diet supplemented with probiotics, was significantly lower (P < 0.05) than those given the non‐supplemented diet.  相似文献   

3.
The study aimed to investigate the effects of maternal dietary methyl donors on the performance of sows and their offspring, and the associated hepatic insulin‐like growth factor‐1 (IGF‐1) expression of the offspring. A total of 24 multiparous sows were randomly fed the control (CON) or the CON diet supplemented with methyl donors (MD) at 3 g/kg betaine, 15 mg/kg folic acid, 400 mg/kg choline and 150 μg/kg VB12, from mating until delivery. After farrowing, sows were fed a common lactation diet through a 28‐days lactation period and six litters per treatment were selected to be fed until at approximately 110 kg BW. Maternal MD supplementation resulted in greater birthweight (p < 0.05) and increased the piglet weights (p < 0.01) and litter weights (p < 0.05) at the age of day 28, compared with that in CON group. The offspring pigs in the MD group had greater ADG (p < 0.05) and tended to lower F:G ratio (p = 0.07) compared with that of CON group from day 28 to 180 of age. The offspring pigs from MD group had greater serum IGF‐1 concentrations and expressions of hepatic IGF‐1 gene and muscular IGF‐1 receptor (IGF‐1r) protein at birth (p < 0.05), and greater hepatic IGF‐1 protein (p = 0.03) and muscular IGF‐1r gene expressions (p < 0.05) at slaughter, than that from the CON group. Moreover, the methylation at the promoter of IGF‐1 gene in the liver of newborn piglets and finishing pigs was greater in the MD group than that of the CON group (p < 0.05). In conclusion, maternal MD supplementation throughout gestation could enhance the birthweight and postnatal growth rate of offspring, associated with an increased expression of the IGF‐1 gene and IGF‐1r, as well as the altered DNA methylation of IGF‐1 gene promotor.  相似文献   

4.
A total of 144 weaned piglets were used to evaluate the effects of essential oil (EO) supplementation of a low‐energy diet on performance, apparent nutrient digestibility, small intestinal morphology, intestinal microflora, immune properties and antioxidant activities in weaned pigs. Pigs received a low‐energy diet (negative control, NC, digestible energy = 3250 kcal/kg), NC plus 0.025% EO or a positive control diet (PC, digestible energy = 3400 kcal/kg) for 28 days. Growth performance was similar between the EO group and PC group. However, EO supplementation increased (P < 0.05) average daily gain and the apparent digestibility of dry matter, crude protein and energy compared with pigs fed the NC diet. Greater (P < 0.05) villus height and lower (P < 0.05) counts of Escherichia coli and total anaerobes in the rectum in the EO group were observed compared with NC or PC groups. Pigs fed EO diet had higher (P < 0.05) concentrations of albumin, immunoglobulin A (IgA), IgG and total antioxidant capacity and lower fecal score than pigs fed the PC and NC diets. Above all, this study indicates that supplementation of EO to a low‐energy pig diet has beneficial results and obtains similar performance compared with normal energy (PC) diet.  相似文献   

5.
The major taste active component, glutamate (Glu), improves the taste of meat. In this study, we investigated the effect of a short‐term high‐protein (HCP) diet on the intramuscular free Glu content to improve the taste of meat. Furthermore, we elucidated how the muscle free Glu content was controlled by the HCP diet. Chicks (14 days old) were fed the control diet or HCP diet for 10 days. Plasma and muscle free amino acid concentrations, and activity and messenger RNA (mRNA) expression of muscle enzymes related to Glu metabolism were determined. Muscle free Glu content was increased (P < 0.01) by 51%. Activity and mRNA expression of glutaminase (GA), which is one of the major Glu‐related enzymes, were significantly decreased (P < 0.05) in the HCP group because of feedback inhibition. The mRNA expression of lysine α‐ketoglutarate reductase (LKR), which is the enzyme involved in lysine (Lys) degradation and Glu production, was significantly increased (P < 0.001) in the HCP group. These results suggest that short‐term dietary HCP feeding is an effective treatment for improving the taste of meat. Furthermore, our results suggest that the free Glu content in muscle is regulated by GA and LKR.  相似文献   

6.
Twenty‐four Chinese Holstein growing steers were randomly divided into three groups and fed a diet containing 0 (the control group), 15 (treatment I group, or TG1) or 25 (treatment II group, or TG2) g/day 2‐hydroxy‐4‐(methylthio) butanoic acid isopropyl ester (HMBi). Compared with the control group, the final body weights, total gains and average daily gains in the treatment groups increased (P < 0.01). The concentration of total protein (TP) for TG1 increased (P < 0.01). The levels of albumin in TG1 were higher than those in TG2 and the control group (P < 0.05). The concentration of alanine aminotransferase (ALT) in TG2 increased (P < 0.05), but concentrations of aspartate aminotransferase (AST) in the treatment groups decreased (P < 0.05). HMBi improved the concentrations of selenium in both TG1 (P < 0.05) and TG2 (P < 0.01). The levels of glutathion peroxidase (GSH‐Px) in TG2 were higher than those of the control group (P < 0.05). Moreover, HMBi increased the concentrations of growth hormone (GH) in both TG1 (P < 0.05) and TG2 (P < 0.01). These results indicate that the addition of HMBi increases growth performance, serum concentrations of GH and AST; 15 g/day HMBi increases concentrations of total protein and albumin, and 25 g/day HMBi increases concentrations of ALT and GSH‐Px.  相似文献   

7.
The objective of this experiment was to investigate the effect of fat supplementation during the transition period on pre and postpartum body weight (BW), body condition score (BCS), non‐esterified fatty acids (NEFA), glucose and leptin concentrations in Holstein cows. Holstein cows (n = 15) received a low fat diet (LF; 1.61 Mcal net energy for lactation (NEL)/kg of dry matter [DM]), moderate fat diet (MF; 1.68 Mcal NEL/kg DM) or a high fat diet (HF; 1.74 Mcal NEL/kg DM) for 4 weeks prior to calving. All cows were fed similar lactation diets ad libitum (1.74 Mcal NEL/kg DM) for 30 days after calving. Increasing diet energy density during transition period had no effect on prepartum DMI, BCS, BW, glucose and NEFA concentrations (P > 0.05); but leptin concentrations and energy balance (EB) were affected by treatments (P < 0.05). Animals fed HF had less plasma leptin prepartum. After parturition, BW, milk production, milk fat, protein, urea nitrogen and plasma glucose concentrations were affected by prepartum diets (P < 0.05). Fat supplementation prepartum did not affect postpartum NEFA. In conclusion, prepartum fat supplementation decreased leptin concentration prepartum.  相似文献   

8.
Effect of supplementing wheat dried distillers’ grain with solubles (DDGS)‐containing diet with enzymes on nutrient utilization by growing pigs was evaluated in two experiments. In Experiment 1, 60 pigs weighing ~30 kg were fed five diets that included a corn‐based diet (Control), Control with 10% wheat DDGS (DDGS‐PC), DDGS‐PC without inorganic P source (DDGS‐NC), and DDGS‐NC plus phytase alone or with multi‐carbohydrase for 4 weeks to determine average daily gain (ADG), average daily feed intake (ADFI) and gain‐to‐feed ratio (G:F). In Experiment 2, 30 barrows weighing 22 kg were fed five diets fed in Experiment 1 to determine nutrient digestibility and retention. Pigs fed DDGS‐PC and Control diets had similar ADG and G:F. The ADG and G:F for DDGS‐PC diet were higher (P < 0.05) than those for DDGS‐NC diet. Phytase improved (P < 0.05) ADG, G:F, total tract P digestibility and P retention by 6.6, 8.7, 86.0 and 85.5%, respectively. Addition of multi‐carbohydrase to phytase‐supplemented diet did not affected growth performance, but reduced (P < 0.05) P retention. In conclusion, inclusion of 10% wheat DDGS in growing pig diet may not affect growth performance of growing pigs. Phytase supplementation to wheat DDGS‐containing diet can eliminate the need for inorganic P supplement in pig diets.  相似文献   

9.
Effects of adding protease with or without fructooligosaccharide (FOS) to low protein diet on growth performance, nutrient digestibility and fecal noxious gas emission were evaluated in 160 finishing pigs (57.70 ± 1.16 kg) in a 9‐week study. Pigs were randomly divided into four dietary treatments, PC: positive control diet (15.97% crude protein (CP)); NC: negative control diet (12.94% CP); PRO: NC supplemented with 0.05% protease; PROFOS: NC supplemented with 0.05% protease and 0.1% FOS. During weeks 4–9 and weeks 0–9, gain : feed ratio was impaired (P < 0.05) in pigs fed NC diet compared with those fed PC, PRO and PROFOS diets. Pigs fed PC, PRO and PROFOS diets had higher (P < 0.05) apparent total tract digestibility (ATTD) of CP than pigs fed NC diet. Pigs fed PROFOS diet had reduced (P < 0.05) ammonia emissions compared to pigs fed NC and PRO diets. These data indicate that reducing dietary CP concentrations impaired growth performance, decreased ATTD of CP and reduced ammonia emissions. Supplementation of protease in low CP diet improved growth performance and increased ATTD of CP. Dietary supplementation with protease and FOS in low CP diet improved growth performance, increased ATTD of CP and decreased fecal ammonia emission.  相似文献   

10.
To investigate the effects of amino acids on ghrelin‐induced growth hormone (GH), insulin and glucagon secretion in lactating dairy cattle, six Holstein cows were randomly assigned to two infusion treatments in a cross‐over design. Mixture solution of amino acids (AMI) or saline (CON) was continuously infused into the left side jugular vein via catheter for 4 h. At 2 h after the start of infusion, synthetic bovine ghrelin was single injected into the right side jugular vein through the catheter. Ghrelin injection immediately increased plasma GH, glucose and non‐esterified fatty acids (P < 0.05) with no difference between both treatments. Additionally, plasma insulin and glucagon concentrations were increased by ghrelin injection in both treatments. The peak value of plasma insulin concentration was greater in AMI compared with CON (P < 0.05). Plasma glucagon concentration showed no difference in the peak value reached at 5 min between both treatments, and then the plasma levels in AMI compared with CON showed sustained higher values (P < 0.05). After plasma glucose concentration reached the peak, the decline was greater in AMI compared with CON (P < 0.05). These results showed that the increased plasma amino acids may enhance ghrelin action which in turn enhances insulin and glucagon secretions in lactating cows.  相似文献   

11.
Eighteen Duroc × Landrace × Yorkshire barrows, with an average initial body weight (BW) of 75.4 ± 2.0 kg, were randomly allotted to one of three diets with six replicates per treatment for 25 days. The diets comprised a normal protein diet (NP, 14.5% crude protein), a low crude protein diet supplemented with 0.27% alanine (LP + Ala, 10.0% crude protein), or a low crude protein diet supplemented with 0.40% leucine (LP + Leu, 10.0% crude protein). The whole‐body protein synthesis rate, whole‐body protein breakdown rate and protein deposition rate in pigs fed the LP + Leu diet were similar to the NP diet (P > 0.05), and both were significantly higher than pigs fed the LP + Ala diet (P < 0.05). The Longissimus muscle area (LMA) of pigs fed the LP + Leu diet was larger than those fed the LP + Ala diet (P = 0.05). In addition, drip loss and intramuscular fat of pigs fed the LP + Ala diet were higher than that of the others (P < 0.05). In conclusion, supplementation of leucine in low protein diet could stimulate protein deposition and improve the meat quality of finishing pigs more than an alanine‐supplemented one.  相似文献   

12.

Background

Stress contributes to reactivation of feline herpesvirus‐1 (FHV‐1). The usage of pheromones to decrease stress in FHV‐1 experimentally inoculated kittens has not previously been investigated.

Hypothesis/Objectives

To determine whether a feline pheromone would lessen stress, resulting in decreased recurrence of FHV‐1‐associated illness in kittens.

Animals

Twelve 5‐month‐old, purpose‐bred kittens.

Methods

Randomized, double‐blind, placebo‐controlled clinical trial. Kittens previously infected with the same dose of FHV‐1 were randomized into 2 separate but identical group rooms. After a 2‐week equilibration period, a diffuser containing either the pheromone or placebo was placed in each of the rooms, and the kittens acclimated for an additional 2 weeks. Every 2 weeks thereafter, for the 8‐week study period, housing was alternated between kennel‐ and group housing. Blinded observers applied a standardized clinical and behavioral scoring rubric daily. After each 2‐week period, serum cortisol concentrations and quantitative PCR for FHV‐1 and glyceraldehyde 3‐phosphate dehydrogenase (GAPDH) ratios were evaluated. Clinical, behavioral, and laboratory test results were compared between groups within individual and combined study periods.

Results

Sneezing occurred more frequently in the placebo group during individual (P = 0.006) and combined study periods (P = 0.001). Sleep at the end of observation periods occurred more frequently in the pheromone group during individual (P = 0.006) and combined study periods (P < 0.001).

Conclusions and Clinical Importance

The findings suggest that the pheromone decreased stress, and the decrease in stress response may have resulted in decreased sneezing associated with FHV‐1.  相似文献   

13.
A study was conducted to investigate effects of zinc‐bearing zeolite clinoptilolite (ZnCP), as an alternative for zinc sulfate (ZnSO4), on laying performance, tissue Zn accumulation and Zn transporter genes expression in laying hens. Hy‐Line Brown laying hens were allocated to three treatments, each of which had six replicates with 15 hens per replicate, receiving basal diet supplemented with ZnSO4 (control, 80 mg Zn/kg diet), 0.23% ZnCP (40.25 mg Zn/kg diet) and 0.46% ZnCP (80.50 mg Zn/kg diet) for 8 weeks, respectively. Compared with control, hens fed diet containing 0.23% ZnCP had similar Zn content in measured tissues (P > 0.05). A higher ZnCP inclusion (0.46%) enhanced Zn accumulation in liver (P < 0.05) and pancreas (P < 0.05). In addition, ZnCP inclusion increased blood iron (Fe) content (P < 0.05). ZnCP supplementation enhanced jejunal metallothionein‐4 (MT‐4) messenger RNA (mRNA) abundance (P < 0.05). ZnCP inclusion at a higher level (0.46%) increased mRNA expression of MT‐4 in pancreas (P < 0.05) and zinc transporter‐1 (ZnT‐1) in jejunum (P < 0.05). The highest ZnT‐2 mRNA abundance in jejunum was found in hens fed 0.23% ZnCP inclusion diet (P < 0.05). The results indicated that ZnCP reached a higher bioavailability as compared with ZnSO4 as evidenced by enhanced tissue Zn accumulation and Zn transporter genes expression.  相似文献   

14.
Threonine (Thr) may be a limiting amino acid for laying hens fed diets with lowered protein level. An experiment was conducted to examine laying performance, and the intestinal immune function of laying hens provided diets varying in digestible Thr levels. Lohmann Brown laying hens (n = 480), 28 weeks of age, were allocated to six dietary treatments, each of which included five replicates of 16 hens. Dietary crude protein (CP) 16.18% diet was offered as the positive control diet. L‐Thr was added to the negative diet (14.16% CP) by 0, 1.0, 2.0, 3.0 and 4.0 g/kg, corresponding 0.44%, 0.43%, 0.49%, 0.57%, 0.66% and 0.74% digestible Thr. At 40 weeks, a reduction in CP level decreased laying performance (p < 0.05). In the low CP, increasing dietary Thr increased (p < 0.05) egg production and egg mass and rose to a plateau between 0.57% and 0.66%. The hens fed 0.66% Thr showed the lowest value (p < 0.05) of feed conversion ratio (FCR). Serum level of uric acid showed the lowest values (p < 0.05) at 0.57–0.66%. In addition, serum‐free Thr maximized (p < 0.05) between 0.66% and 0.74%. Digestive trypsin activity decreased (p < 0.05) when hens fed the low‐CP diet compared with hens fed CP (16.18%) and hens fed 0.57–0.66%. Expressions of ileal MUC2 mRNA maximized (p < 0.05) at 0.66% Thr. Occludin mRNA increased with increasing Thr level (p < 0.05). sIgA mRNA reached to the maximum level (p < 0.05) at 0.66% and 0.74% Thr. INF‐γ mRNA reached to the lowest level (p < 0.05) at 0.65%. Expressions of ileal IL‐2, IL‐6, IL‐1β mRNA decreased with increasing Thr level (p < 0.05). In conclusion, Thr supplementation resulting in optimal laying performance and stimulated the mucosal immune system, suggesting that it is a limiting amino acid in the low‐crude‐protein diet of laying hens during the peak production period.  相似文献   

15.
Thirty‐five laying hens of a medium‐weight hybrid strain, aged 10 months, were given a basal diet containing 11.5% protein or the same diet supplemented with 1.54% essential amino acids and/or with two sources of nitrogen for the synthesis of non‐essential amino acids (1.15% urea or 9.7% dried autoclaved poultry manure) for an 8‐week period.

Egg production, food intake, food conversion efficiency, the gross efficiency of nitrogen conversion and the ability of hens to maintain body weight were improved by supplementation with essential amino acids (P < 0.05 or P < 0.01). Supplementation with dried autoclaved poultry manure raised food intake, total egg mass and mean egg weight (P < 0.05), but supplementation with urea alone did not result in significantly higher egg production, perhaps because it failed to increase food intake. Supplementation with essential amino acids and urea to give the equivalent of 16% protein did not result in significantly higher egg production than that obtained with urea alone. The smallest eggs were produced by hens fed on the diet supplemented with urea, and the largest by those fed on the diet supplemented with dried manure (P < 0.001).

The gross composition of eggs was not influenced significantly by dietary treatment but albumen quality was significantly lower on the basal diet and higher on the supplemented diets (P < 0.001). It was highest in eggs from hens fed on the diet supplemented with urea alone.  相似文献   


16.
Low protein provision in utero and post‐partum may induce metabolic disorders in adulthood. Studies in mink have mainly focused on short‐term consequences of low protein provision in utero whereas the long‐term responses to low protein (LP) provision in metabolically programmed mink are unknown. We investigated whether low protein provision in utero affects the long‐term response to adequate (AP) or LP provision after weaning in male mink. Eighty‐six male mink were exposed to low (19% of ME from CP; crude protein) or adequate (31% of ME from CP) protein provision in utero, and to LP (~20% of ME from CP) or AP (30–42% of ME from CP) provision post‐weaning. Being metabolically programmed by low protein provision in utero did not affect the response to post‐weaning diets. Dietary protein content in the LP feed after weaning was below requirements; evidenced by lower nitrogen retention (p < 0.001) preventing LP mink from attaining their growth potential (p < 0.02). LP mink had a lower liver, pancreas and kidney weight (p < 0.05) as well as lower plasma IGF‐1 concentrations at 8 and 25 (p < 0.05) weeks, and a higher incidence of hepatic lipidosis at 25 weeks (p < 0.05). Furthermore, LP mink had a higher body fat (p < 0.05) and lower body CP content (p < 0.05) at 50 weeks of age. It is concluded that some effects of low protein provision in utero can be alleviated by an adequate nutrient supply post‐partum. However, long‐term exposure to low protein provision in mink reduces their growth potential and induces transient hepatic lipidosis and modified body composition.  相似文献   

17.
This study was conducted to evaluate the effects of dietary supplementation of protease derived from Pseudoalteromonas arctica (PPA) in finishing pigs. A total of 160 pigs were used in this 10‐week trial. Dietary treatment groups were as follows: CON (basal diet); TRT1 (basal diet + 0.1% PPA); TRT2 (basal diet + 0.2% PPA); and TRT3 (basal diet + 0.3% PPA). During weeks 1–5, pigs fed with different levels of PPA‐supplemented diet showed linear increase (p < .05) in the apparent total tract digestibility (ATTD) of nitrogen (N) and linear decrease (p < .05) in the concentrations of serum total protein. During weeks 6–10, pigs fed with different levels of PPA‐supplemented diet showed a linear decrease in feed conversion ratio (p < .05). During the overall period, there was a linear decrease in feed conversion ratio (p < .05) associated with the inclusion of PPA. Pigs fed diets with 0.2% PPA supplementation had lower (p < .05) feed conversion ratio than those fed CON diet during weeks 6–10 and the overall period, and had higher (p < .05) ATTD of N than those fed CON diet during weeks 1–5. Pigs fed diets with PPA supplementation had lower (p < .05) concentrations of serum total protein than those fed CON diet on week 5. In conclusion, dietary supplementation with PPA diet has beneficial effects on growth performance, nutrient digestibility, backfat thickness and the concentrations of serum total protein.  相似文献   

18.
A total of 64 5‐month‐old Pietrain pigs were randomly allocated to four treatments with four replicates per treatment according to body weight. The pigs were fed either a standard corn‐soybean meal based control diet (treatments 1 and 2), the standard diet with 1% Lycium barbarum (LB) (treatment 3), or the standard diet with 1% Polygala tenuifolia Willd (PT) (treatment 4). Serum lactic acid and glucose concentrations were increased in stressed pigs (P < 0.05). Addition of the herbs in the diet had no effect on the serum lactic acid concentration, but 1% LB decreased (P < 0.05) serum glucose concentration in the stressed pigs. Pre‐slaughter stress also decreased (P < 0.01) liver glycogen concentration and the decrease could be inhibited by addition of 1% LB in the diet (P > 0.05). Pre‐slaughter stress increased the concentration of maleic dialdehyde (MDA) (P < 0.05) and decreased glutathione peroxidase (GSH‐Px) activity in serum, while dietary 1% LB increased (P < 0.05) the activity of GSH‐Px and decreased the concentration of MDA in the serum. In conclusion, pre‐slaughter stress induces oxidative stress in pigs and dietary supplementation with 1% LB improves antioxidant capacity in stressed pigs before slaughtering.  相似文献   

19.
To investigate effects of Aspergillus oryzae culture (AOC) and 2‐hydroxy‐4‐(methylthio) butanoic acid (HMB) on milk performance and rumen fermentation of dairy cows. Sixty‐four multiparous Chinese Holstein cows were randomly allocated into four experimental diets: (i) Control diet; (ii) AOC diet: 5 g AOC/day per head; (iii) HMB diet: 25 g HMB/day; and (iv) AH diet: 5 g AOC plus 25 g HMB/day. Added HMB tended to increase the yield of milk protein (P = 0.06) and 3.5% fat‐corrected milk (P = 0.08) and milk fat content (P = 0.09). Milk fat yield (P = 0.03) and the contents of milk protein (P = 0.05) were increased by adding HMB. The cows fed on AOC diet had a tendency for higher body weight (BW) gain (P = 0.08). Addition of AOC, HMB and AH increased content of microbial protein (MCP) and total volatile fatty acids (VFA) (P < 0.01) in rumen fluid. Populations of rumen fungi, Fibrobacter succinogenes and Ruminococcus flavefaciens relative to total bacterial 16S rDNA (P ≤ 0.03) and activity of carboxymethylcellulase (CMCase) (P < 0.01) were increased with added AOC or HMB. It is inferred that added AOC or HMB can increase the contents of MCP and total VFA potentially by stimulating rumen microbe populations and CMCase activity.  相似文献   

20.
This study examined the molecular mechanisms of methionine pathways in meat‐type chickens where birds were provided with a diet deficient in methionine from 3 to 5 weeks of age. The birds on the deficient diet were then provided with a diet supplemented with either D,L‐methionine or D,L‐HMTBA from 5 to 7 weeks. The diet of the control birds was supplemented with L‐methionine from hatch till 7 weeks of age. We studied the mRNA expression of methionine adenosyltransferase 1, alpha, methionine adenosyltransferase 1, beta, 5‐methyltetrahydrofolate‐homocysteine methyltransferase, 5‐methyltetrahydrofolate‐homocysteine methyltransferase reductase, betaine‐homocysteine S‐methyltransferase, glycine N‐methyltransferase, S‐adenosyl‐L‐homocysteine hydrolase and cystathionine beta synthase genes in the liver, duodenum, Pectoralis (P.) major and the gastrocnemius muscle at 5 and 7 weeks. Feeding a diet deficient in dietary methionine affected body composition. Birds that were fed a methionine‐deficient diet expressed genes that indicated that remethylation occurred via the one‐carbon pathway in the liver and duodenum; however, in the P. major and the gastrocnemius muscles, gene expression levels suggested that homocysteine received methyl from both folate and betaine for remethylation. Birds who were switched from a methionine deficiency diet to one supplemented with either D,L‐methionine or D,L‐HMTBA showed a downregulation of all the genes studied in the liver. However, depending on the tissue or methionine form, either folate or betaine was elicited for remethylation. Thus, mRNA expressions show that genes in the remethylation and transsulphuration pathways were regulated according to tissue need, and there were some differences in the methionine form.  相似文献   

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