The digestion of chopped and ground roughages by sheep. I. Movement of digesta through the stomach

1967 ◽  
Vol 18 (5) ◽  
pp. 789 ◽  
Author(s):  
RH Weston ◽  
JP Hogan
Keyword(s):  
Retention Time ◽  
Metabolizable Energy ◽  
Water Soluble ◽  
Ad Libitum ◽  
Ad Libitum Intake ◽  
Ad Libitum Feeding

Digestion studies were conducted with lucerne hay and wheaten hay prepared for feeding either by chopping or by grinding and pelleting. The sheep were offered food every 3 hr. The rates of flow of water and the rumen volumes were measured by reference to a water-soluble marker. The replacement of a diet of chopped roughage by an equal amount of ground roughage caused a decline in the rate of flow of water from the rumen. With wheaten hay this decreased flow was accompanied by a decline in rumen volume, the retention time of the marker in the rumen remaining constant; with lucerne hay the rumen volume remained constant and the retention time of the marker increased. When the quantity of ground roughage feed was increased, rates of flow from the rumen and abomasum were enhanced and marker retention time in the rumen decreased. Under conditions of ad libitum feeding, the sheep consumed 75% more chopped lucerne hay than chopped wheaten hay; grinding was accompanied by an increase of 50% in the consumption of each hay. When levels of feeding were approximately 90% of the ad libitum intake, it was found that: (i) the rate of flow from the rumen appeared to be independent of diet and method of preparation of the feed; (ii) the rate of flow from the abomasum was higher with the ground roughage; (iii) rumen volume with ground lucerne hay was higher than with chopped lucerne hay or ground wheaten hay; it was also higher with chopped wheaten hay as compared with ground wheaten hay. Sheep spent less time ruminating and eating when the roughages were ground. The amount of metabolizable energy available for production from 1000 g of ground lucerne hay was 950 kcal; it was calculated that this would have declined by 9% if the sheep ruminated for the same time on this ground hay as on the chopped hay.

The digestion of pasture plants by sheep. II. The digestion of ryegrass at different stages of maturity

1968 ◽  
Vol 19 (6) ◽  
pp. 963 ◽  
Author(s):  
RH Weston ◽  
JP Hogan
Keyword(s):  
Organic Matter ◽  
Propionic Acid ◽  
Volatile Fatty Acids ◽  
Metabolizable Energy ◽  
Water Soluble ◽  
Feed Consumption ◽  
Net Energy ◽  
Dietary Nitrogen ◽  
Ad Libitum ◽  
Ad Libitum Intake

Ryegrass harvested at various stages of maturity was dried and offered to sheep either ad libitum or at approximately 90% of the ad libitum intake. Feed consumption and the times spent by the sheep in ruminating and eating were measured when the forages were offered ad libitum, and several aspects of digestion were studied when the level of feeding approached 90% of ad libitum intake. The chemical composition of the grasses and the apparent digestibility of the constituents showed the usual changes with maturity. As the grass matured, there was a tendency for: (i) the rate of flow of digesta from the abomasum to increase relative to the flow from the rumen, (ii) the concentration of organic matter in digesta leaving the abomasum to decrease, (iii) the quantity of nitrogen leaving the stomach in digesta per unit intake of dietary nitrogen to increase, and (iv) the sheep to spend more time in ruminating and eating per unit feed intake. No differences attributable to maturity were observed in: (i) the rate of flow of digesta from the rumen, (ii) the retention time of a water-soluble marker in the rumen, (iii) rumen volume, (iv) the distribution of the digestion of organic matter and carbohydrate between the stomach and intestines, and (v) the apparent digestion of nitrogen in the intestines. Although the quantity of nitrogen provided by 100 g of forage organic matter decreased with maturity from 4.3 to 1.2 g, the corresponding change in the quantity of nitrogen, in forms other than ammonia, apparently digested in the intestines was only 2.6 to 1.5 g. It was calculated, after making several assumptions, that the net energy value of the metabolizable energy derived from volatile fatty acids produced in the rumen and from amino acids digested in the intestines was little affected by the stage of maturity. On the other hand, after making assumptions about the energy costs of ruminating and eating, it was calculated that the proportion of the metabolizable energy used in ruminating and eating could increase from 5% with the immature grass to 13% with mature grass. Intraruminal infusion of propionic acid did not increase the sheep's intake of one forage that provided a relatively small quantity of propionic acid during ruminal digestion.

Daily changes in food availability, but not long-term unpredictability, determine daily torpor-bout occurrences and frequency in stripe-faced dunnarts (Sminthopsis macroura)

2015 ◽  
Vol 63 (1) ◽  
pp. 12 ◽  
Author(s):  
Alexandra M. Leslie ◽  
Mathew Stewart ◽  
Elizabeth Price ◽  
Adam J. Munn
Keyword(s):  
Food Availability ◽  
Control Period ◽  
Daily Torpor ◽  
Torpor Bout ◽  
Effect Of Food ◽  
Rapid Adjustment ◽  
Sminthopsis Macroura ◽  
Ad Libitum ◽  
Ad Libitum Intake ◽  
Ad Libitum Feeding

Daily torpor, a short-term reduction in body temperature and metabolism, is an energy-saving strategy that has been interpreted as an adaptation to unpredictable resource availability. However, the effect of food-supply variability on torpor, separately from consistent food restriction, remains largely unexamined. In this study, we investigated the effect of unpredictable food availability on torpor in stripe-faced dunnarts (Sminthopsis macroura). After a control period of ad libitum feeding, dunnarts were offered 65% of their average daily ad libitum intake over 31 days, either as a constant restriction (i.e. as equal amount of food offered each day) or as an unpredictable schedule of feed offered, varied daily as 0%, 30%, 60%, 100% or 130% of ad libitum. Both feeding groups had increased torpor-bout occurrences (as a proportion of all dunnarts on a given day) and torpor-bout frequency (average number of bouts each day) when on a restricted diet compared with ad libitum feeding, but torpor frequency did not differ between the consistently restricted and unpredictably restricted groups. Most importantly, torpor occurrence and daily bout frequency by the unpredictably restricted group appeared to change in direct association with the amount of food offered on each day; torpor frequency was higher on days of low food availability. Our data do not support the interpretation that torpor is a response to unpredictable food availability per se, but rather that torpor allowed a rapid adjustment of energy expenditure to manage daily fluctuations in food availability.

THE TRUE METABOLIZABLE ENERGY AND AMINO ACID CONTENT OF CANDLE, ALTEX AND REGENT CANOLA MEALS

1982 ◽  
Vol 62 (2) ◽  
pp. 521-525 ◽  
Author(s):  
A. JABBAR MUZTAR ◽  
S. J. SLINGER
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Content ◽  
Basal Diet ◽  
Metabolizable Energy ◽  
Canola Meal ◽  
Force Feeding ◽  
Ad Libitum ◽  
Ad Libitum Feeding ◽  
New Cultivars

Rapeseed (Canola) meals derived from two B. napus cultivars, Altex and Regent, were studied for their true metabolizable energy (TME) and amino acid (AA) contents and the results were compared with meal from the B. campestris cultivar, Candle. The TME was determined by force-feeding the ingredients singly as well as by feeding them ad libitum for 1.5 h in conjunction with a basal diet. The Regent meal showed a significantly (P < 0.05) higher TME value than Altex or Candle when fed singly. However, based on the results obtained by ad libitum feeding of these samples mixed with a basal diet, there was no significant (P > 0.05) difference in the TME values of any of the three meals. This latter result was in keeping with their proximate composition which was fairly similar for all three meals. When calculated as a percentage of the protein, Candle meal was slightly higher in most of the essential AA as compared with the Altex and Regent meals. However, considering all of the parameters used, the new cultivars Altex and Regent should be as vauable for the nutrition of poultry as the Candle meal. Key words: Canola meal, Candle, Altex, Regent, True metabolizable energy, amino acids

scholarly journals Ruminal capacity, and digesta weight and retention time in the different segment of primiparous Holstein dairy cows in early lactation at ad libitum feeding

2009 ◽  
Vol 80 (4) ◽  
pp. 457-463 ◽  
Author(s):  
Makoto MIYAJI ◽  
Tomoko OSHITA ◽  
Yasuhiro AOKI ◽  
Masato NAKAMURA ◽  
Mari AOKI ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Retention Time ◽  
Early Lactation ◽  
Ad Libitum ◽  
Ad Libitum Feeding ◽  
Holstein Dairy Cows

Skin folds and Merino breeding. 9. Efficiency of conversion of food to wool

1976 ◽  
Vol 16 (80) ◽  
pp. 361 ◽  
Author(s):  
GE Robards ◽  
CH Davis ◽  
DG Saville
Keyword(s):  
Surface Area ◽  
The Other ◽  
Or Efficiency ◽  
Wool Production ◽  
Skin Fold ◽  
Significant Difference ◽  
Ad Libitum ◽  
Ad Libitum Intake ◽  
Ad Libitum Feeding ◽  
Reduced Surface

This paper reports a study of the efficiency of wool production, liveweight change and ad libitum intake of 60 hogget ewes from flocks selected for 15 years for skin wrinkle (Folds Plus), against skin wrinkle (Folds Minus) and randomly selected as a control (Random). Initially, under restricted feeding ewes from each genetic flock consumed 594, 750, 951 or 1097 g DM day-1 of a lucerne pellet ration. The mean efficiency of clean wool production of Folds Minus ewes (8.47 g CW/kg D.M.I.) was less (P < 0.05) than that of either Random (9.38) or Folds Plus (10.18) ewes, which did not differ significantly. During the following ad libitum feeding period, the Folds Minus ewes again produced less wool than either of the other groups and their wool production was less efficient even though they consumed significantly less feed than either Random or Folds Plus ewes. The significant difference in intake between Random and Folds Minus ewes remained when the n takes were corrected for liveweight (kg), metabolic body size (kg0.73) or surface area based on liveweight alone (kg0.67). However, when fold score (FS) was included in the surface area estimate as LW0.67 + FS0.2 the intake difference between flocks became very small. The experimental results and components analyses of the pre- and post-shearing data showed that selection for skin fold had not changed wool growth rate or efficiency of wool production, but had reduced staple length. On the other hand, the lower wool production of Folds Minus ewes was due to both reduced surface area and lower wool production per unit area.

scholarly journals Energy partition for maintenance and weight gain in Nellore and crossbred steers finished under grazing

2011 ◽  
Vol 40 (4) ◽  
pp. 922-928
Author(s):  
N.F. Sant´Ana ◽  
C.A.A. Fontes ◽  
E.F. Processi ◽  
J.G. Siqueira ◽  
A.M. Fernandes ◽  
...  
Keyword(s):  
Body Weight ◽  
Linear Model ◽  
Reference Group ◽  
Experimental Period ◽  
Metabolizable Energy ◽  
Net Energy ◽  
Full Time ◽  
Indicator Method ◽  
Ad Libitum ◽  
Ad Libitum Feeding

The objective of this work was to estimate net energy (NEm) and metabolizable energy (MEm) requirements for maintenance and efficiency of use of metabolizable energy for maintanence (k m) and gain (k g) of grazing Nellore and crossbred steers. It was used 24 castrated steers, 12 Nellore breed (386 kg SBW) and 12 ½ Limousin-Nelore crossbred (397 kg SBW). The comparative slaughter method was used. In each genetic group, animals were grouped in three similar groups: reference; restrict feeding and ad libitum feeding. The reference group was slaughtered in the beginning of the experiment whereas the others were slaughtered at the end of it. During the 104 days of the experimental period, the group under restrict feeding had access to pastures for 3.5 hours daily whereas the group with ad libitum feeding remained on pasture full time. Forage intake was estimated in two trials by using the double-indicator method. Values of NEm, MEm, k m and k g were estimated on the basis of empty body weight (EBW) through linear and non-linear model fitting. Requirements of NEm and MEm did not differ among Nellore and crossbred animals. In the linear model, the following results were obtained: Requirements of NEm = 86 kcal/kg0.75; requirements of MEm = 136 kcal/kg0.75 and k m = 0.63. Kg value was higher for Nellore animals (0.39) than for crossbred animals (k g = 0.33). Requirement of net energy of maintenance does not differ among grazing Nellores and ½ European-Nellore crossbred. For the same body weight, Nellore animals present greater fat proportion in gain composition than ½European-Nelore crossbred.

Nutritional status and intake regulation in sheep. IV. The influence of protein supplements upon acetate and propionate tolerance of sheep fed on low quality chaffed oaten hay

1965 ◽  
Vol 16 (3) ◽  
pp. 473 ◽  
Author(s):  
AR Egan
Keyword(s):  
Physiological Mechanism ◽  
High Protein Diet ◽  
Metabolizable Energy ◽  
Protein Diet ◽  
Protein Supplements ◽  
Low Protein ◽  
Acetate Utilization ◽  
Ad Libitum ◽  
Ad Libitum Intake ◽  
Intake Regulation

Under ad libitum feeding conditions, injected acetate disappeared more slowly from the blood of sheep fed on a diet of low protein oaten chaff than when 6% casein was added to the diet. Only 2 days after the sheep were changed from the high to the low protein diet, the rate of disappearance of injected acetate dropped considerably. An equally rapid rise occurred when the sheep were changed from the low to the high protein diet. After receiving casein per duodenum for 3 days, sheep fed ad libitum on low quality oaten chaff improved in their ability to cope with injected acetate.Propionate tolerance was rapidly improved when sheep were transferred from a low quality oaten chaff diet to one supplemented with casein, each offered ad libitum. The changes in ability to cope with acetate load are discussed in relation to possible mechanisms concerned, and a physiological mechanism of regulating voluntary feed intake is suggested. It is emphasized that further investigations are needed of the effect(s) of the nature of the diet upon the sheep's ability to utilize the metabolizable energy at ad libitum intake, particularly upon the avenues and efficiency of acetate utilization.

scholarly journals EFFECT OF FEED RESTRICTION AND REALIMENTATION ON NUTRIENT UTILIZATION AND CARCASS COMPOSITION OF ZEBU BULLS

2021 ◽  
Vol 16 ◽  
pp. 55-60
Author(s):  
O. W. Ehoche ◽  
W. S. Alhassan ◽  
V. Buvanendran ◽  
J. E. Umoh ◽  
N. N. Umanna
Keyword(s):  
Crude Protein ◽  
Nutrient Utilization ◽  
Carcass Composition ◽  
Metabolizable Energy ◽  
Feed Restriction ◽  
Feeding Regimes ◽  
Digestible Crude Protein ◽  
Compositional Changes ◽  
Ad Libitum ◽  
Ad Libitum Feeding

Forty-eight Sokoto Gudali bulls were used to study carcass compositional changes and nutrient efficiency following feed restriction (25% ad libitum feeding, L., and 54% ad. libitum feeding, M) and realimentation (ad. libitum feeding, H). The treatments were designated as LLH, LMH and LHH according to the level of feeding for each of three periods within each treatment group. Representative bulls were slaughtered at the beginning of the study and at the end of each feeding period. At the end of the mid period, animals on the LLH and LMH feeding regimes had higher percentages of water, similar percentages of protein and ash but lower proportions of fat and energy compared to animals on the LHH feeding regime. Following realimentation in the final period carcass gains contained approximately 21.0, 15.0, 18.5% protein and 22.0, 31,0 and 29.6% fat for LLH, LMH and LHH bulls respectively. The LHH animals were more efficient in utilizing metabolizable energy for carcass energy gain than the LLH and LMH animals. Digestible crude protein (DCP) efficience for carcass protein gain averaged 17.6, 26.2 and 35.4 g DCP/g protein gain for LLH, LMH and LHH bulls respectively. The results suggest that improved efficiency of protein utilization is largely responsible for compensatory carcass growth in zebu bulls. 

BODY COMPOSITION AND ENERGY METABOLISM DURING LATE PREGNANCY IN THE AD LIBITUM-FED EWE

1975 ◽  
Vol 55 (4) ◽  
pp. 545-555 ◽  
Author(s):  
D. P. HEANEY ◽  
G. A. LODGE
Keyword(s):  
Body Composition ◽  
Mammary Gland ◽  
Late Pregnancy ◽  
Plasma Free Fatty Acid ◽  
Fat Deposition ◽  
Metabolizable Energy ◽  
Ad Libitum ◽  
Total Body Composition ◽  
Total Body ◽  
Ad Libitum Feeding

Sixty mature ewes (Rambouillet × Columbia type) were grouped into tetrads on the basis of initial weight and paired within tetrads as a pregnant (P) and a nonpregnant (NP) for slaughter at day 105 of the pregnancy of the former, and a P and NP for slaughter at day 140 of the pregnancy of the former. All were fed a restricted allowance 20% above estimated maintenance until day 70 of the pregnancy of the P member of each pair, when they were changed over a 14-day period to ad libitum feeding with a higher energy diet. Feed intakes reached maxima for both P and NP ewes in the final week at levels approximately twice maintenance. During the final 35 days, P ewes gained more weight than NP ewes but not significantly so. Differences in fat percentages of carcass and viscera between P and NP ewes and between 105 and 140 days were not significant. There were, however, significant differences in fat percentages of liver, fleece, mammary gland and uterus between P vs. NP and 105 vs. 140. Significant differences in protein percentage occurred only in fleece, mammary gland and uterus. Total contents of fat were higher in several components at 140 than at 105 days in both P and NP ewes; total contents of protein showed significant differences only for fleece, mammary gland and uterus. Differences in total body composition, some significant, indicated that both P and NP ewes increased their fat and water contents during the final 35 days, with little or no change in protein, but that pregnancy tended to enhance water rather than fat deposition. In spite of the evidence of fat deposition during late pregnancy, plasma free fatty acid (FFA) levels were significantly elevated in P ewes at day 140 compared either with previous samplings or the level in NP ewes at day 140. Efficiency of metabolizable energy (ME) utilization during the final 35 days of pregnancy for growth of concepta including mammary gland and uterus was 26.9%, and for the uterine contents alone, 21.3%.

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