Fermented Diet Research Articles

Fermentation of a High Concentrate Diet as Affected by Ruminal pH and Digesta Flow

Continuous culture fermentations were conducted to determine the effect of pH and digesta flow rates on fermentation of a 65% grain, 35% forage ration by rumen microorganisms. The pH selected were 5.8, 6.2, 6.6, and 7.0. Imposed on each pH in a randomized complete block design were digesta flow rates of 30/4, 26/8, 22/12, and 18/16, where the first number represents solids retention time (hour) and the second the liquid dilution rate (percent/hour).Digestibility of organic matter, neutral detergent fiber, and nitrogen was significantly depressed at pH 5.8, increased markedly at pH 6.2, and increased only slightly at pH 7.0. Digestibility of total nonstructural carbohydrate averaged 91.4% and was not affected by digesta flow rate or pH.Production of total volatile fatty acid was highest at pH 6.2 and 6.6. Overall means for acetate production increased, but propionate and butyrate production decreased as pH was increased from 5.8 to 6.2 with little response to further pH increases.Microbial efficiency decreased with increasing pH but increased 36% as digesta flow rate increased. The percentage of the microbial population associated with effluent neutral detergent fiber was decreased when pH was reduced below 6.2, which reflects the pattern seen for fiber digestion.

Dietary fibre contents and compositions of sorghum and sorghum-based foods

The compositions of dietary fibre (DF) and acid detergent fibre (ADF) fractions of sorghum-based diets common in Sudan were investigated in relation to the nutritional characteristics of the diets as determined in rat feeding experiments. Energy availability decreased on cooking and 60% of the loss could be explained by the formation of a form of starch that resists enzyme digestion during DF determination. Polyphenols caused significant increases in the levels of lignin in the DF fraction from the various products, both before and after cooking. Fermentation to pH 3·9 before cooking counteracted the formation of enzyme-resistant starch, whereas immediate acidification to pH 3·9 did not. Low pH (3·9) inhibited the formation of lignin during cooking. Large amounts of protein were associated with the DF and ADF fractions of sorghum, which differs in this respect from cereals, such as wheat, maize, rye and barley. The levels of ADF-bound protein were correlated more closely with true protein digestibility values in the sorghum diet material than were those of DF-bound protein. The amino acid composition of the (low lysine) ADF proteins in all diets resembles that of kafirin. The amounts of protein that bind to the DF and ADF fractions increased on cooking the foods or if sorghum with high polyphenol content was used. Fermentation or acidification to pH 3·9 inhibited this protein binding effect in materials containing either high or low levels of polyphenols, reflecting the reduced binding of the kafirins under these conditions. The results are consistent with the observed beneficial nutritional effect of the traditional method of fermentation of sorghum diets in Sudan.

Effect of monensin on the fermentation of basal rations in the Rumen Simulation Technique (Rusitec)

1. A long-term experiment was made with the Rumen Simulation Technique (Rusitec), in which the fermentation of a mixed ration of hay (10 g/d) and bruised barley (5 g/d) was compared with the fermentation of the same diet in the presence of 2, 10 and 50 mg monensin/d. 2. Monensin depressed the production of acetic and butyric acids, markedly increased the production of propionic acid and virtually, eliminated the production of isovaleric acid. The production of methane was decreased in the presence of monensin, but this decrease could be accounted for entirely by the changes in the production of volatile fatty acids and redistribution of metabolic hydrogen. 3. The digestibility of dry matter (DM) in the rations declined in the presence of monensin. Determinations of the rates of digestion showed that the digestion of the readily-fermented food in the initial stages was not affected by monensin, but that at 24 h digestion had been inhibited by monensin. The inhibition was due entirely to its effect on the digestion of the fibrous components. Digestion of non-fibrous material was not affected. 4. The efficiency of microbial growth, expressed as g dry weight/mol ATP formed (YATP) and in terms of DM digested, tended to be increased by monensin. This however occurred only at high, non-practical doses. 5. Urease (EC 3. 5. 1. 5) was induced by the addition of urea of the fermentation, but monensin had no effect on urease activity. Although monensin increased the activity of protease in washed suspensions, more food protein apparently escaped degradation. This may have been due to decreased deaminative activity. 6. Monensin altered the microscopic appearance of the fermentation fluid, and changed the activity of some enzymes in sonicated extracts, including alkaline phosphatase (EC 3. 1. 3. 1), acetate kinase (EC 2. 7. 2. 1) and succinate dehydrogenase (EC 1. 3. 99. 1). These results are discussed in terms of known sensitivities of rumen microbes to monensin and their contribution to the fermentation as a whole.

Effect of fermentation and palm oil on the performance of broilers receiving cassava diets in the tropics

ABSTRACTThe effect of fermentation on cassava meal diets supplemented with 0, 2, 4 and 6% levels of palm oil on the performance, carcass characteristics and economic value of broiler chickens was studied. During the growing phase, fermentation had no influence on growth rate, but resulted in reduced mortality and improved efficiency of feed utilization in the chickens. However, there were greater intakes of fermented cassava meal diets, higher efficiency of feed utilization, better growth rate and reduced mortality during the finishing phase. Abdominal fat was lower during both phases in chickens given the fermented cassava meal diets than those given the cassava meal diets. There was evidence of economic benefits in reduced feed cost, increased gross revenue and higher revenue less feed cost values in fermented cassava meal than in cassava meal diets. There were non-significant reductions in feed intake, mortality rate, daily rate of gain, final body weight and carcass quality, but significant economic benefits during both growing and finishing phases as the level of supplementary palm oil increased in the diets. The results suggest that while about 2% palm oil might be required in fermented cassava meal diets, 2 to 4% would be needed in cassava meal diets by broiler chickens for comparable performance.

Comparison of Cattle Finishing Diets Containing Various Physical Forms of Corn

Animal performance and rumen parameters were studied with steers fed a cracked corn diet that contained 20% peanut hulls (PH), an all-concentrate diet containing unground dry shelled corn (DC) or an all-concentrate diet containing ensiled high-moisture shelled corn (HMC). Total digestible nutrient (TDN) values were similar for the DC and HMC diets and about 19% greater (P < .05) than TDN values for the PH diet. Rumen fluid from steers fed DC and HMC contained less (P < .05) protozoa and more (P < .05) bacteria than did rumen fluid from steers fed PH. The PH diet produced a greater (P < .10) molar percentage of acetic acid and less (P < .10) propionic acid than did fermentation of the all-concentrate diets. Steers fed for either 98 or 161 days responded similarly to dietary treatment. Compared with DC and HMC fed steers, all groups fed the PH diet gained faster (P < .05) and required about 10% less TDN per kilogram of body weight gain. With the exception of carcass weight, carcass characteristics were not different (P < .05) due to dietary treatment.

Ruminant-like digestion of the langur monkey.

The adaptation of langur monkeys to a laboratory environment has made possible a detailed investigation of their digestive physiology. The diverticular form of the langur stomach permits a bacterial fermentation of the leafy diet, which results in important contributions to the nutrition of these primates. The demonstration of a ruminant-like digestion in langurs extends the known taxonomic distribution of this digestive adaptation.

β-Carotene vs. Retinyl Acetate for the Baby Pig and the Effect upon Ergocalciferol Requirement

Twenty-four pigs were used in a study to compare the utilization of dietary fermentation β-carotene with retinyl acetate by the baby pig and to determine whether β-carotene has a rachitogenic effect which may increase the vitamin D requirement. Purified isolated-soy diets containing 2.5, 6.25 or 12.5 μg of ergocalciferol/kg and containing either 8 mg/kg of fermentation β-carotene or 688 μg/kg of retinyl acetate were used in a 5-week feeding period. Total liver vitamin A storage of pigs receiving preformed vitamin A was about twice that of pigs receiving β-carotene (2.4 mg vs. 1.2 mg). Neither bone composition nor strength were greatly affected by source of vitamin A activity. In this experiment β-carotene did not increase the need for ergocalciferol above that normally required by baby pigs fed a soy protein diet containing retinyl acetate.

Utilization of salts of volatile fatty acids by growing sheep. IV. Effects of type of fermentation of the basal diet on the utilization of salts of volatile fatty acids for nitrogen retention and body gains.

1. Two experiments are reported in which sodium and calcium salts of volatile fatty acids (VFA) were given to lambs as additions to two basal dietsof hay andconcentrate. The two diets induced distinctly different types of rumen fermentation. A low-concentrate diet gave higher acetic and lower butyric acid proportions in the rumen contents than a high-concentrate diet. The two diets were given to lambs to provide equal intake of digestible organic matter. In one change-over experiment with twelve sheep the nitrogen retention was determined, and in a second experiment involving sixty-four lambs the efficiency of the VFA salt to promote body-weight gain was estimated. 2. The estimated metabolizable energy (ME) from the high-concentrate diet was utilized significantly more efficiently than that from the low-concentrate diet to promote positive nitrogen retention and to increase empty body-weight and carcass weight. These differences in final live weight were not significant owing to the greater content of the alimentary tract of lambs given the low-concentrate diet. 3. On both diets the lambs receiving the additions of VFA salts grew faster and produced significantly greater empty body and carcass weights than the lambs receiving only the basal diets. 4. For promoting carcass gain the energy derived from the VFA salts appeared to be utilized more efficiently than the calculated ME above maintenance of the two basal diets. 5. There were no significant differences between the efficiency of utilization of the energy from acetate, propionate and butyrate to promote carcass gains. There was, however, a tendency for the response to acetate to be greater on the high-concentrate diet than on the low-concentrate diet. 6. With a low level of feeding but with positive N balance, addition of acetate resulted in a greater N retention than that of propionate with both diets. 7. It is concluded that if the reported low utilization of the ME of diets high in roughage is related to the proportion of acetic acid in the rumen contents, then the implied losses of energy may be associated with the formation of acetic acid rather than its utilization.

The analysis of dietetic treatment of constipation.

1. The dietetic treatment of constipation works mainly by chemical stimuli of bowel movement in the residue of food. 2. The chemical stimuli are organic acids produced out of carbohydrates by fermentating bacteria in the colon. 3. Foods loosening bowel movement contain carbohydrates protected by cellulose from being absorbed in the small intestines or sugars given in such a way that they escape partially absorption in the small intestines. 4. A diet combating constipation should be better named high fermentation diet than high residue or bulk diet.

THE EFFECT OF PROTRACTED EXERCISE, INTESTINAL FERMENTATION, AND MODIFICATION OF DIET ON THE ATTAINMENT OF ABNORMAL RESPIRATORY QUOTIENTS BY RATS ON A FAT-DEFICIENT INTAKE

THE EFFECT OF PROTRACTED EXERCISE, INTESTINAL FERMENTATION, AND MODIFICATION OF DIET ON THE ATTAINMENT OF ABNORMAL RESPIRATORY QUOTIENTS BY RATS ON A FAT-DEFICIENT INTAKE

The Use of Fermented Milk and Milk Diets in Controlling Intestinal Putrefaction

The Use of Fermented Milk and Milk Diets in Controlling Intestinal Putrefaction