RUMINAL DIGESTION OF ALFALFA STRAINS SELECTED FOR SLOW AND FAST INITIAL RATES OF DIGESTION

1985 ◽  
Vol 65 (1) ◽  
pp. 157-161 ◽  
Author(s):  
H. KUDO ◽  
K.-J. CHENG ◽  
M. R. HANNA ◽  
R. E. HOWARTH ◽  
B. P. GOPLEN ◽  
...  

A feeding trial, using six fistulated sheep, was conducted to evaluate two strains of alfalfa that were selected for slow and fast initial rates of digestion (IRD). To determine how these strains affect rumen metabolism, samples of rumen fluid were collected before feeding, as well as 2 h and 4 h after feeding. Concentrations of soluble protein, soluble carbohydrates, chlorophyll, volatile fatty acids and hydrogen ions were significantly lower in rumen fluid from sheep fed slow-IRD alfalfa compared to sheep fed fast-IRD alfalfa. These results show that the bloat-causing potential of alfalfa might be reduced through further breeding for slow-IRD strains. Key words: Bloat, legumes, Medicago sativa L., nylon bag, chlorophyll, pH

1982 ◽  
Vol 99 (1) ◽  
pp. 215-224 ◽  
Author(s):  
J. C. Mathers ◽  
E. L. Miller

SUMMARYTwo experiments were carried out with adult sheep to investigate the effects of chloral hydrate (CH) on rumen metabolism and on the sites and extent of digestion.Experiment 1 confirmed that CH is a very potent methane inhibitor; doses of 1 or 4 g/day reduced methane production to 4% of that observed in the absence of the drug. In both experiments, CH administration altered the proportions of volatile fatty acids in rumen fluid. The main changes were an increase in propionic acid and a decrease in acetic acid with smaller increases in the proportion of isovaleric, valeric and caproic acids. Stoichiometric calculations indicated that only 21% of the hydrogen saved by prevention of methanogenesis was diverted to the synthesis of additional propionic and butyric acids and the fate of the remaining hydrogen was not determined unequivocally.CH had little effect on the extent of biohydrogenation in the rumen of the long-chain fatty acids in dried grass.The apparent digestibility of ether extract was reduced (P< 0·05) by CH but those of other proximate constituents and energy were little affected. There were no s gnificant effects of CH on the extent of digestion of dry matter, organic matter, non-ammonia nitrogen or ash between the mouth and abomasum, abomasum and terminal ileum or ileum and anus.


1976 ◽  
Vol 56 (2) ◽  
pp. 227-232 ◽  
Author(s):  
S. O. THORLACIUS

Manure from a commercial feedlot was dehydrated at an alfalfa dehydration plant. The manure contained, on a dry matter (DM) basis, 14.8% crude protein, 14% ash, 0.83% calcium, 0.69% phosphorus, 30.5% crude fiber, and 2.6% fat. About 45% of the DM in the manure was wheat straw bedding. Each of three pelleted rations: 50% hay 50% barley (HB); 50% manure 50% barley (MB); and 100% manure (M) was fed ad libitum to eight individually penned yearling wethers in a 38-day feeding trial. In addition to the manure pellets, lambs on ration M were fed 200 g/day alfalfa hay until intake of pellets exceeded 600 g/day, and 200 g/day barley during the first 28 days on test. A digestibility trial, five wethers per treatment, was conducted after the 38-day feeding trial. Mean daily DM intake during the feeding trial was 2,054, 1,714, 1,165 (pellets only) g and mean daily gain was 272, 148 and −57 g for rations HB, MB, and M, respectively. The corresponding values were 2,632, 2,277, and 2,050 g for DM intake during the final 10 days of the feeding trial, 62.7, 51.7, and 26.7% for DM digestibility, and 70.9, 62.6, and 42.2 for nitrogen digestibility. Molar percent volatile fatty acids in rumen fluid of lambs on ration M were similar to those normally observed for high roughage rations. Molar percent acetic in rumen fluid of lambs on ration HB was greater (P < 0.05) and percent valeric lower (P < 0.05) than on ration MB. It was concluded that sheep will consume rations containing large amounts of dehydrated manure, but low digestibility of manure severely limits its value as a ration ingredient.


Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1247
Author(s):  
Xin Wu ◽  
Shuai Huang ◽  
Jinfeng Huang ◽  
Peng Peng ◽  
Yanan Liu ◽  
...  

The rumen contains abundant microorganisms that aid in the digestion of lignocellulosic feed and are associated with host phenotype traits. Cows with extremely high milk protein and fat percentages (HPF; n = 3) and low milk protein and fat percentages (LPF; n = 3) were selected from 4000 lactating Holstein cows under the same nutritional and management conditions. We found that the total concentration of volatile fatty acids, acetate, butyrate, and propionate in the rumen fluid was significantly higher in the HPF group than in the LPF group. Moreover, we identified 38 most abundant species displaying differential richness between the two groups, in which Prevotella accounted for 68.8% of the species, with the highest abundance in the HPF group. Functional annotation based on the Kyoto Encyclopedia of Gene and Genome (KEGG), evolutionary genealogy of genes: Non-supervised Orthologous Groups (eggNOG), and Carbohydrate-Active enzymes (CAZy) databases showed that the significantly more abundant species in the HPF group are enriched in carbohydrate, amino acid, pyruvate, insulin, and lipid metabolism and transportation. Furthermore, Spearman’s rank correlation analysis revealed that specific microbial taxa (mainly the Prevotella species and Neocallimastix californiae) are positively correlated with total volatile fatty acids (VFA). Collectively, we found that the HPF group was enriched with several Prevotella species related to the total VFA, acetate, and amino acid synthesis. Thereby, these fulfilled the host’s needs for energy, fat, and rumen microbial protein, which can be used for increased biosynthesis of milk fat and milk protein. Our findings provide novel information for elucidation of the regulatory mechanism of the rumen in the formation of milk composition.


1971 ◽  
Vol 51 (3) ◽  
pp. 721-727 ◽  
Author(s):  
L. J. FISHER ◽  
J. D. ERFLE ◽  
F. D. SAUER

Glutamate, succinate, propylene glycol, or glycerol were added to a basic concentrate at 3.3% of air-dry feed. Each concentrate was fed both ad libitum and in restricted amounts to four cows in early lactation. Dietary intake, milk yield and composition, molar proportions of rumen volatile fatty acids and blood glucose, ketones and plasma free fatty acids were used as criteria of effect of these supplements. Propylene glycol in the diet resulted in a lower intake of concentrate compared with glycerol (11.44 versus 14.30 kg/day) and significantly decreased (P < 0.05) rumen butyrate and plasma beta-hydroxybutyrate. Glutamate supplementation prevented the fall in milk fat content which occurred when the other three supplemented concentrates were fed ad libitum, and this effect may have been related to the constancy in the ratio of acetate to propionate in the rumen fluid.


1929 ◽  
Vol 19 (4) ◽  
pp. 649-655 ◽  
Author(s):  
V. Subrahmanyan

Methods for extraction, concentration and determination of minute quantities of soluble carbohydrates, lactic acid and volatile fatty acids have been described. Different factors affecting the accuracy of the determinations have been studied and corrections, where necessary, have been suggested.


2018 ◽  
Vol 39 (6) ◽  
pp. 2621
Author(s):  
Ludmila Couto Gomes ◽  
Claudete Regina Alcalde ◽  
Julio Cesar Damasceno ◽  
Luiz Paulo Rigolon ◽  
Ana Paula Silva Possamai ◽  
...  

Feeding goats with calcium salts of fatty acids (CSFA) can supply ruminants with lipids, with minimal effects on ruminal fermentation and fiber digestibility. However, there is a shortage of information on the effect of CSFA on characteristics of rumen fermentation in grassland goats. Thus, the present study aimed to assess the addition of CSFA to concentrate on the parameters of rumen fermentation of grazing goats. Five rumen cannulated goats were distributed in a Latin square 5x5 design (treatments: 0%, 1.5%, 3.0%, 4.5% and 6.0% CSFA. The pH, ammonia N and volatile fatty acids (VFA) content were analyzed in the ruminal fluid at 0, 2, 4, 6 and 8 hours after concentrate supplementation. The pH and ammonia N concentration showed a linear effect with the addition of CSFA. There was no effect observed for the VFA molar concentration after grazing goats were fed with the experimental diet. In conclusion, further research is needed to investigate the addition of CSFA to goat diets because there is evidence that CSFA increases ruminal pH and decreases excess ruminal ammonia without changing the VFA concentration in the rumen fluid.


2011 ◽  
Vol 79 (1) ◽  
pp. 16-25 ◽  
Author(s):  
Qendrim Zebeli ◽  
Sarah J Terrill ◽  
Alberto Mazzolari ◽  
Suzanna M Dunn ◽  
Wen Z Yang ◽  
...  

This study evaluated the effects of intraruminal administration ofMegasphaera elsdeniion ruminal fermentation patterns, the profile of plasma metabolites, and milk yield and composition of mid-lactation dairy cows. Eight primiparous, ruminally cannulated Holstein cows were arranged in a paired 2×2 crossover design. Cows were randomly assigned to one of two treatments: 1) intraruminal inoculation of 35 ml suspension per day ofM. elsdeniiATCC 25940 (MEGA), containing 108cfu/ml of bacteria, dissolved in 35 ml of saline (0·15m), or 2) carrier alone (35 ml saline; CTR). Both postprandial and preprandial rumen volatile fatty acids (VFA) and plasma metabolite measurements were analysed. Postprandial VFA patterns were affected the most, with butyrate (P<0·01) and valerate (P<0·01) proportions increasing, and acetate (P<0·01), isobutyrate (P=0·05) and isovalerate (P<0·01) decreasing in MEGA cows. Preprandial data measured at various days showed that MEGA dosage tended to increase the molar proportion of propionate (P=0·09) and lower the acetate to propionate ratio (P=0·07) in the rumen fluid. There was no effect of treatment on rumen pH and on the concentration of lactate in the rumen as well as on selected preprandial plasma metabolites. Postprandial plasma concentrations of cholesterol tended to increase (P=0·07) in MEGA cows compared with CTR. Concentrations of non-esterified fatty acids (NEFA) in the plasma were lower in MEGA cows after the morning feeding (P<0·01). Sampling hour also affected plasma NEFA in this study. Plasma β-hydroxybutyrate (BHBA) were not affected by the treatment (P>0·05); however, after the morning feeding BHBA concentration was increased in both groups of cows. Dry matter intake and milk yield and composition were not affected by treatment. In conclusion, results indicate thatM. elsdeniihas the potential to modulate the rumen fermentation profile in mid-lactation Holstein cows, but these effects were only slightly reflected in changes in plasma metabolites and milk composition.


1980 ◽  
Vol 94 (1) ◽  
pp. 219-227 ◽  
Author(s):  
C. G. Wernli ◽  
R. J. Wilkins

SummaryGrass silage (21.0 % D.M.) was given ad libitum to sheep together with supplements of rolled barley, dried-grass pellets or dried-grass wafers at 12 and 25 g organic matter (OM)/kg0·75.Intake of silage was greater with supplement at 12 g/kg0·75 but total intake of OM and digestible organic matter (DOM) increased with increasing supplement. Intake of OM was higher with the pellet supplement than with other supplements. Intake of DOM, however, did not differ between the pellet and barley treatments, but was lower with wafers.Concentrations of ammonia and total volatile fatty acids and the molar proportions of butyric and higher volatile fatty acids were higher when silage was supplemented with barley than with dried grass. Mean rumen retention times of silage and of supplement were highest in the barley-supplemented treatments. Dried-grass wafers were retained longer than dried-grass pellets. Supplement treatments did not differ significantly for eating and ruminating times, rumen fluid volume and pH, digestion rate in the rumen and nitrogen retention.At the low supplement rate silage consumption may have been controlled by factors associated directly with the silage, whereas at the high rate intake was limited either by physical factors or by the potential energy demand of the animals.


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