Factors limiting the intake of feed by sheep. 15. Voluntary feed consumption and digestion in lambs fed chopped roughage diets varying in quality

1989 ◽  
Vol 40 (3) ◽  
pp. 643 ◽  
Author(s):  
RH Weston
Keyword(s):  
Organic Matter ◽  
Energy Metabolism ◽  
Large Particle ◽  
Alimentary Tract ◽  
Feed Consumption ◽  
Published Data ◽  
Small Particles ◽  
High Quality ◽  
Particle Content ◽  
Digestible Organic Matter

Feed intake and digestion transactions for diets based on wheaten straw and mature ryegrass diets, both supplemented to provide additional essential nutrients, were compared with those for lucerne hay and high quality forage oats diets in lambs weighing c. 24 kg. The data obtained and comparable published data were used to examine relationships between a range of variables. Decrease in roughage quality, as evidenced by decrease in digestible organic matter (OM) intake, was accompanied by increase in (i) times spent eating, ruminating and chewing rumination boluses, (ii) the quantities of digesta or digesta OM in the reticula-rumen and omasum. It was not associated with increase in the large particle content of rumen or omasum digesta. Over the range of diets, close direct relations were demonstrated between (i) ruminating time and the amount of digesta in the reticulo-rumen, (ii) the amounts of digesta in the reticulo-rumen and omasum, (iii) the OM concentrations in rumen and reticulum digesta, (iv) the OM concentrations in reticulum and omasum digesta, (v) the OM concentration of reticulum digesta and of digesta flowing to the omasum, and (vi) the increase in OM concentration from reticulum to omasum digesta and OM concentration of reticulum digesta. Reticulum digesta were of finer texture than rumen digesta, and the bulk density of digesta particle fractions varied between diets, and sometimes between rumen and large intestine digesta. With a straw-based diet, relative to lucerne hay, small particles ( <600 �m sieve) were cleared more slowly from the reticula-rumen, associated with a larger reticulo-rumen particle pool. The data are discussed in relation to (i) the flow of digesta through the alimentary tract and (ii) the regulation of roughage intake. They were considered to be consistent with a concept that energy metabolism and digesta load in the reticulo-rumen interact in the regulation of roughage intake.

The effect of antibiotics on ammonia accumulation and protein digestion in the rumen

1969 ◽  
Vol 20 (2) ◽  
pp. 339 ◽  
Author(s):  
JP Hogan ◽  
RH Weston
Keyword(s):  
Organic Matter ◽  
Food Intake ◽  
Dietary Protein ◽  
Alimentary Tract ◽  
Protein Digestion ◽  
Microbial Protein ◽  
Ammonia Accumulation ◽  
Digestible Organic Matter

A study was made of the feasibility of using antibiotics to reduce ruminal deamination of protein that comprised 27% of the organic matter in a diet of lucerne hay and casein. Six sheep were each dosed with a different antibiotic. At the levels given, penicillin and erythromycin reduced rumen ammonia levels by about 35%, but also reduced food intake. Chloramphenicol reduced rumen ammonia by about 50% but neomycin, oxytetracyclene, and streptomycin had little effect.When all six sheep were subsequently dosed with chloramphenicol at 1 g/day the levels of rumen ammonia were reduced only to 85% of the control. The antibiotic had little effect on the extent of digestion of protein, organic matter, and cellulose, both in the stomach and in the whole alimentary tract, and on parameters associated with the movement of digesta through the stomach The quantity of nitrogen passing from the stomach in forms other than ammonia was 52–54% of intake during both the control and treatment periods. Much of this nitrogen probably passed from the stomach in the form of microbial protein, which indicated that the dietary protein was extensively digested. In consequence of the loss of nitrogen from the stomach, the protein apparently digested in the intestines was equivalent to only about 14.5 g/100 g digestible organic matter.

The utilization of spear grass (Heteropogon contortus). I. Factors limiting intake and utilization by cattle and sheep

1972 ◽  
Vol 23 (1) ◽  
pp. 35 ◽  
Author(s):  
BD Siebert ◽  
PM Kennedy
Keyword(s):  
Organic Matter ◽  
Feed Intake ◽  
Feed Consumption ◽  
Total Organic Matter ◽  
Mineral Supplement ◽  
Heteropogon Contortus ◽  
Total Intake ◽  
Digestible Organic Matter ◽  
Maintenance Requirements ◽  
Cattle And Sheep

The addition of 13.6% lucerne to a diet of spear grass increased the total intake of digestible organic matter of cattle by nearly 30%. Further additions (24.5 and 44.9%) increased the total organic matter intake, but decreased the spear grass intake. In cattle, the digestibility of the spear grass portion of the diet appeared to decrease as lucerne was added to the diet. Sheep consumed and digested spear grass poorly, although an addition of 14.4% legume increased both digestibility and intake. Further additions of legume slightly decreased the digestibility of the spear grass. The addition of urea alone did not influence digestion or feed intake by either cattle or sheep. When cattle were fed on spear grass, urea, and minerals, the quantity of organic matter digested was not significantly different from that with a diet of spear grass and 20% lucerne. The digestibility of the spear grass was not influenced by urea and minerals, whereas it decreased with the addition of lucerne. Increased feed consumption was maintained when various components of the mineral supplement were withdrawn, excepting nitrogen and sulphur. The energy derived from diets of spear grass and lucerne or spear grass and minerals appears to be above the maintenance requirements of cattle, but below those of sheep.

Factors limiting the intake of feed by sheep. V. Feed intake and the productive performance of the ruminant lamb in relation to the quantity of crude protein digested in the intestines

1971 ◽  
Vol 22 (2) ◽  
pp. 307 ◽  
Author(s):  
RH Weston
Keyword(s):  
Organic Matter ◽  
Crude Protein ◽  
Dry Matter ◽  
Tritiated Water ◽  
Essential Amino Acids ◽  
Feed Consumption ◽  
Wool Production ◽  
Volatile Fatty Acid Concentration ◽  
Digestible Organic Matter ◽  
Peripheral Blood Plasma

The voluntary feed consumption (VFC), liveweight increase, and wool growth of lambs, initially 9-10 weeks old and weighing 22 kg, were measured over 6 weeks when pelleted diets of differing protein content were offered. The crude protein contents of the diets, on a dry matter basis, were 11.7% (LP diet), 15.8% (MP diet), and 19.1 % (HP diet). The digestion of the HP and LP diets was studied, with use of markers, in similar lambs prepared with stomach fistulae. VFC, expressed as grams dry matter/day/kg body weight0.75, was 82 (SE�3) with the LP diet, 94�3 with the MP diet, and 97�4 with the HP diet. The dietary crude protein intakes were 110, 178, and 220 g/day with the LP, MP, and HP diets respectively and the corresponding quantities of crude protein (6.25 x nitrogen in forms other than ammonia) apparently digested in the intestines (DCP,) were 75, 134, and 179 g/day. The LP and HP diets provided about 12 and 23 g DCP1/lOO g digestible organic matter respectively; the value for the MP diet was estimated to be 18 g DCP1/100 g. The rates of liveweight increase were 153 � 16, 240�9, and 267�12 g/day with the LP, MP, and HP diets respectively. Wool production was the same with the MP and HP diets but lower with the LP diet. The level of intake of DCP1 and the DCP1/digestible organic matter ratio had little effect on the gross chemical composition of the lambs, as estimated indirectly from tritiated water space. The levels of essential amino acids in peripheral blood plasma were generally in the order HP diet > MP diet > LP diet. Digesta flow from the rumen and abomasum, rumen volume, ruminal volatile fatty acid concentration, and pH of ruminal digesta were similar with the LP and HP diets. It was concluded that a level of about 18 g DCP1/100 g digestible organic matter was adequate for the expression of maximum VFC and that concentrations in excess of this would have little enhancing effect on liveweight gain or wool production under conditions of ad libitum feeding.

Factors limiting the intake of feed by sheep. IX.* Further studies of the roughage requirement of the ruminant lamb fed on concentrate diets based on wheat

1979 ◽  
Vol 30 (3) ◽  
pp. 533 ◽  
Author(s):  
RH Weston
Keyword(s):  
Body Weight ◽  
Organic Matter ◽  
Weight Gain ◽  
Body Weight Gain ◽  
Feed Consumption ◽  
Whole Grain ◽  
Slow Adaptation ◽  
Digestible Organic Matter ◽  
Ground Wheat ◽  
Prolonged Feeding

The voluntary feed consumption (VFC) and body weight gain of lambs initially weighing 22 kg were measured when pelleted diets based on ground wheat grain and varying in content of ground straw were offered. VFC increased progressively as the straw content of the diet was increased from 2% through 8% to 14%. Lambs fed on the diets with 8 and 14% straw performed similarly, whereas those with 2% straw had lower rates of body weight gain (– 11%) and intakes of digestible organic matter (– 4%). Increase in straw content from 2 to 14% was accompanied by a decrease in diet digestibility and increases in (i) the rates of flow from the rumen of digesta, sodium and potassium, (ii) the pH of ruminal contents, and (iii) the time spent ruminating. Lambs initially weighing 37 kg were offered 'roughage-free' concentrate diets based on wheat in which the wheat was presented either as whole grain or in ground and pelleted form. With whole grain, values for VFC, digestible organic matter intake and body weight gain were respectively 17, 17 and 29% higher than with ground grain. The feeding of whole grain instead of ground grain increased the time spent daily in ruminating from 0.3 to 2.2 h. It was concluded that the roughage requirement of the ruminant lamb fed on concentrate diets based on wheat was higher when the wheat was in ground form than when whole grain was used. The requirement with ground wheat diets was tentatively assessed as in the range of 2–8 g ground straw per 100 g diet. Lambs were slow in adapting to a chopped roughage diet following prolonged feeding with wheat-based diets. VFC data suggested that the slow adaptation was associated with changes in rumen function. _______________ *Part VIII, Aust. J. Agric. Res., 25, 349 (1974).

UTILIZATION OF SUGAR CANE FINAL MOLASSES BY THE PIG: ENERGY METABOLISM

1983 ◽  
Vol 63 (2) ◽  
pp. 455-462 ◽  
Author(s):  
H. S. BAYLEY ◽  
VILDA FIGUEROA ◽  
J. LY ◽  
A. MAYLIN ◽  
A. PEREZ
Keyword(s):  
Organic Matter ◽  
Energy Metabolism ◽  
Sugar Cane ◽  
Dry Matter ◽  
Metabolizable Energy ◽  
The Other ◽  
Feed Consumption ◽  
Sugar Mixture ◽  
Energy Retention ◽  
Metabolizable Energy Intake

A sample of sugar cane final molasses (82.5% dry matter) contained the following components (percent of dry matter): ash, 11.4; sucrose, 32.8; fructose, 21.1; glucose, 7.4; and unidentified organic matter, 27.3. Three diets were prepared by mixing soybean meal with either starch, molasses, or a mixture of sugars to simulate those in the molasses. The digestible and metabolizable energy values of the diets were measured with pigs of approximately 35 kg liveweight. The digestible and metabolizable energy values of the molasses were 12.3 and 11.8 MJ/kg dry matter, respectively. The metabolizable energy values of the sugar mixture and the unidentified organic matter were 16.5 and 6.1 MJ/kg, respectively. The heat production of pigs of approximately 13 kg liveweight was measured following the consumption of the three diets, and their energy retention was calculated. The metabolizable energy from the molasses was retained at least as well as that from the other two diets, showing that the mixture of glucose and fructose absorbed from the molasses was an efficient metabolic fuel. These observations suggest that the reduction in performance which usually follows the substitution of molasses for cereals in pig diets is due to the low metabolizable energy value of the molasses coupled with failure of the pigs to increase feed consumption to maintain metabolizable energy intake. Key words: Molasses, pigs, digestible energy, metabolizable energy, respiration calorimetry

Factors limiting the intake of feed by sheep. II. Studies with wheaten hay

1967 ◽  
Vol 18 (6) ◽  
pp. 983 ◽  
Author(s):  
RH Weston
Keyword(s):  
Organic Matter ◽  
Feed Intake ◽  
Crude Protein ◽  
Alimentary Tract ◽  
Wheat Gluten ◽  
Feed Consumption ◽  
Limiting Factor ◽  
Mineral Supplement ◽  
Digestible Energy ◽  
Additional Protein

A study was made of factors limiting the sheep's intake of a wheaten hay diet having an organic matter digestibility of approximately 57% and containing 4.4% crude protein and a mineral supplement. Voluntary consumption of chopped wheaten hay increased by 8–13% when protein was infused per abomasum, or when the protein content of the diet was raised to 7 or 15% by the addition of wheat gluten. A similar change in voluntary feed consumption (VFC) was observed in one of two experiments in which urea was infused per abomasum. The VFC response to protein infusion per abomasum persisted for at least 2 weeks after the infusion was terminated. Voluntary consumption of a diet of chopped wheaten hay + gluten (85/15) did not change when additional protein and micronutrients were provided. When the wheaten hay was ground or ground and pelleted, VFC increased and digestibility declined; the intake of digestible energy showed little change. The addition of protein to the ground and pelleted hay was accompanied by substantial rises in feed intake, digestible energy intake, and digestible fibre intake and in the quantity of organic matter transferred through the alimentary tract. The provision of protein and grinding and pelleting increased the intake of wheaten hay to 189% of that attained when chopped hay was offered. The intake of wheaten hay + gluten (85/15) was lower than that of lucerne hay when the diets were in either chopped or ground and pelleted forms; these diets had similar organic matter digestibilities and protein contents. The results were considered to support the conclusion that the primary factor limiting the intake of the wheaten hay was a deficiency of nitrogen, and that after this had been remedied, the next limiting factor was the resistance of the diet to removal from the rumen. The mechanisms whereby various factors limit intake are discussed, and it is suggested that digestibility is likely to be unreliable for predicting the VFC of non-pregnant, non-lactating ruminants.

The voluntary intake and digestibility by cattle and sheep of dried grass wafers containing particles of different size

1972 ◽  
Vol 14 (2) ◽  
pp. 177-188 ◽  
Author(s):  
R. J. Wilkins ◽  
C. R. Lonsdale ◽  
R. M. Tetlow ◽  
T. J. Forrest
Keyword(s):  
Organic Matter ◽  
Alimentary Tract ◽  
Fine Particles ◽  
Binding Agent ◽  
Milled Material ◽  
Digestible Organic Matter ◽  
Low Modulus ◽  
Voluntary Intake ◽  
The Difference ◽  
Cattle And Sheep

SUMMARYWafers of dried grass which differed in particle size (modulus of fineness) were prepared and fed ad libitum to cattle and sheep. The response of the two classes of stock to the feeds was similar. The digestibility of organic matter and of cellulose decreased with decrease in modulus of fineness (more fine particles) and this was associated with more rapid passage of the finely-milled material through the alimentary tract. Organic matter intake generally increased with decrease in modulus of fineness, but the pattern of response differed between experiments. In one experiment the difference in voluntary intake between feeds with modulus of fineness of 2·5 and 1·0 was less than 5% and not significant, but in a second experiment the intake of feed with modulus of fineness of 2·1 was 18% lower than that of feed with modulus of fineness of 1·0. In the first experiment the wafers broke down during handling and feeding with the result that the feed of low modulus of fineness was extremely dusty, but in the second experiment a binding agent was included and little breakdown of wafers occurred. It is suggested that dustiness may have restricted the intake of some of the feeds in the first experiment. Intakes of digestible organic matter did not differ significantly between treatments in either experiment.

REDUCTION IN PARTICLE SIZE DURING RUMINATION IN CATTLE

1984 ◽  
Vol 64 (5) ◽  
pp. 339-340 ◽  
Author(s):  
K. CHAP ◽  
L. P. MILLIGAN ◽  
P. M. KENNEDY
Keyword(s):  
Particle Size ◽  
Key Words ◽  
Large Particle ◽  
Small Particles ◽  
Particle Content ◽  
Once Daily ◽  
Coarse Material ◽  
Brome Grass

Measurements of chewing behavior and of large particle breakdown during rumination were made with two steers given chaffed alfalfa or brome grass once daily for 4 h. Large particle content of boli retained in the mouth for chewing was enhanced by 38% compared to that in the regurgitated bolus, since some small particles were swallowed immediately with fluid. 58–75% of this coarse material was reduced to small particles by rumination. Specific fragility of both roughages was doubled at 16 vs. 4 h after feeding. Key words: Rumination, chewing, cattle

Factors limiting the intake of feed by sheep. III. The mean retention time of feed particles in sections of the alimentary tract

1968 ◽  
Vol 19 (2) ◽  
pp. 261 ◽  
Author(s):  
RH Weston
Keyword(s):  
Body Weight ◽  
Organic Matter ◽  
Retention Time ◽  
Small Proportion ◽  
Alimentary Tract ◽  
Small Particles ◽  
Mean Retention Time ◽  
The Mean ◽  
Ad Libitum ◽  
The Difference

The mean retention time of feed particles in the alimentary tract of sheep was measured by means of a stained-particle technique, when lucerne hay or a diet of wheaten straw + wheaten hay (1 : 1) was offered ad libitum. The levels of intake of the straw diet and lucerne hay were equivalent to 11.8 and 25.8 g organic matter/day/kg body weight. The mean retention time of particles in the entire alimentary tract when the straw diet was offered was 57.5 hr, this consisting of 36.3 hr in the rumen + omasum and 21.2 hr in the abomasum + intestines. The retention time in the rumen + omasum was calculated to consist of (a) 19.7 hr during which the particles were being degraded to a size at which transfer from the rumen could be readily effected, and (b) 16.6 hr of residence in the rumen + omasum as small particles. With lucerne hay, the retention times were shorter: small particles spent 10.8 hr in the rumen + omasum and retention time in the abomasum + intestines was 16.1 hr. It was calculated that only a small proportion of the difference between the straw diet and lucerne hay in organic matter intake could be attributable to differences between the diets in the rate of removal of finely divided particles of organic matter from the rumen.

scholarly journals Population improvement and synthetic cultivar production in forage kale (Brassica oleracea L.)

Euphytica ◽  
2021 ◽  
Vol 217 (7) ◽  
Author(s):  
John E. Bradshaw
Keyword(s):  
Organic Matter ◽  
Annual Cycle ◽  
Dry Matter ◽  
No Reduction ◽  
Optimum Number ◽  
Breeding Method ◽  
Thiocyanate Ion ◽  
Digestible Organic Matter ◽  
Population Improvement ◽  
Field Transplant

AbstractExperimental results are brought together to demonstrate that forage kale population improvement involving full-sib and selfed families can be done on an annual cycle, followed by production of a synthetic cultivar. Furthermore, this new breeding method compares favourably with the two successful methods used to date, namely triple-cross hybrid cultivars from inbreeding and crossbreeding programmes and open-pollinated cultivars from population improvement programmes. The key findings were that natural vernalization of kale in south east Scotland occurred by mid-December so that plants could be pollinated in a glasshouse with heating and lighting by the end of February and seed harvested by the end of May. The resulting full-sib or selfed families could be assessed in a field transplant trial in the same year, from June to November, thus completing an annual cycle. Self-pollination resulted in shorter plants with lower fresh-weight, dry-matter and digestible organic-matter yields, and undesirably higher contents of S-methylcysteine sulphoxide, the haemolytic anaemia factor, and the goitrogenic thiocyanate ion. As a consequence of digestible organic-matter yield being reduced by as much as 22%, the estimated optimum number of selfed parents in a synthetic cultivar was four to eight. Synthetic cultivars are expected to yield as well as triple-cross hybrids as there was no reduction in yield when the latter were open-pollinated.

Sign in / Sign up

Export Citation Format

Share Document