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 Increased feed consumption was maintained when various components of the mineral supplement were withdrawn, excepting nitrogen and sulphur.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.

Stimulation of wool growth by thyroxine implantation. II. Feed intake of grazing Merino wethers treated repeatedly with thyroxine.

1964 ◽  
Vol 15 (4) ◽  
pp. 676 ◽  
Author(s):  
LJ Lambourne
Keyword(s):  
Organic Matter ◽  
Feed Intake ◽  
Sheep Grazing ◽  
Wool Production ◽  
Wool Growth ◽  
Digestible Organic Matter ◽  
The Difference ◽  
Maintenance Requirements ◽  
Substantial Rise ◽  
Stimulation Of

Estimates have been made of the feed intake of wethers that received implantations of 60 mg thyroxine every 3 months, and of untreated sheep, grazing together. The estimated intake of digestible organic matter (D.O.M.) by treated wethers was higher than that of controls in 24 out of 27 measurement periods. The difference in feed intake was least in the iirst month after implantation, when the treated sheep lost weight, and greatest in the second and third months when the treated sheep were regaining weight. The overall increase in intake resulting from thyroxine treatment (20–25%) was greater than the increase in wool production (7% greasy weight, 3-7 % clean weight), and the efficiency of wool production was therefore lower in thyroxinetreated wethers. From the relationships between feed intake and rate of weight change it was concluded that in the month after implantation, when pulse rates indicated a substantial rise in metabolic rate, the maintenance feed requirement was raised from about 560 g to about 780 g D.O.M. per day. Observations in two winters with recently shorn sheep gave estimates of maintenance requirements for untreated wethers ranging from 850 to 1300 g D.O.M. per day. During recovery from repeated thyroxine implantation the wethers gained in weight no more efficiently than the controls. The mechanism of action of exogenous thyroxine is discussed in the light of these and other data.

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 use of chromium oxide and faecal nitrogen concentration to estimate the pasture intake of Merino wethers

1963 ◽  
Vol 14 (2) ◽  
pp. 257 ◽  
Author(s):  
LJ Lambourne ◽  
TF Reardon
Keyword(s):  
Organic Matter ◽  
Feed Intake ◽  
Nitrogen Concentration ◽  
Linear Equations ◽  
Large Measure ◽  
Feed Digestibility ◽  
Wide Range ◽  
Digestible Organic Matter ◽  
Faecal Nitrogen ◽  
Maintenance Requirements

Statistical analysis of the results of digestion trials on a wide range of fresh pasture herbages shows that their digestibility might be estimated as the intake factor or feed faeces ratio (Y) from the equation: YO.M. = (2.04 – 0.24XN ± 0.186X2N) ± 0.53 where YO.M. is the intake factor for organic matter, and XN is the percentage of nitrogen in faecal organic matter. The results were subdivided arbitrarily into "summer" (September–April) and "winter" (May–August) periods, and these proved to yield significantly different linear equations. The summer regression yielded higher intake factors (corresponding to 2–3% higher digestibility) for a given value of faecal nitrogen percentage. This subdivision reduced the standard deviation from regression only slightly, to about 0.50, which amounts to ± 17% for pasture of 75% digestibility. These equations give considerably lower values of digestibility for a given nitrogen concentration than regressions hitherto published. The present pooled equation, based on short leafy herbage, probably gives sounder estimates for grazing sheep than do the existing equations derived from trials with more mature herbages. When sheep with a wide range in body weight were all fed a maintenance ration, it was found that feed digestibility was not detectably reduced at high levels of feeding. The undoubtedly higher feed intake of grazing than of pen-fed animals, due in large measure to their higher maintenance requirements, therefore may not cause the reduction in digestive efficiency, and thus the bias in estimates of feed intake, that has been supposed. On the basis of the pooled regression, which is felt to be preferable to a subjectively selected "seasonal" equation, estimates of the intake of digestible organic matter (D.O.M.) by sheep in metabolism pens fed on fresh pasture herbage averaged 97 ± 22% of the true figures, or ± 80 g D.O.M.

Estimates of the energy required for maintenance by adult sheep 2. Grazing sheep

1963 ◽  
Vol 5 (1) ◽  
pp. 11-16 ◽  
Author(s):  
J. P. Langlands ◽  
J. L. Corbett ◽  
I. McDonald ◽  
G. W. Reid
Keyword(s):  
Organic Matter ◽  
Energy Cost ◽  
Functional Relationship ◽  
Adult Sheep ◽  
Maintenance Requirement ◽  
Digestible Organic Matter ◽  
Faecal Nitrogen ◽  
Grazing Period ◽  
The Mean ◽  
Maintenance Requirements

SUMMARYThe mean daily digestible organic matter intake (D) of each of 47 adult sheep during a grazing period of mean length 48 days was estimated by the chromium sesquioxide/faecal nitrogen technique. Mean live-weights (W) and mean daily weight gains (G) were also measured.The regression of D on W and G, and the underlying or functional relationship between D, W and G were both estimated. From the underlying relationship, the preferred equation, the maintenance requirement of a 100 lb. sheep at pasture is estimated to be 1·02 lb. digestible organic matter daily. This value is 24% higher than the corresponding value for housed sheep obtained previously by us.This result is compared with other estimates of the energy cost of grazing and it is concluded that further work is needed in order to define those circumstances which elevate the maintenance requirements of grazing animals.

Effects of duration of introductory feeding and barley content of pelleted diets on the feed intake and liveweight of export sheep

1989 ◽  
Vol 29 (2) ◽  
pp. 169 ◽  
Author(s):  
MH Round
Keyword(s):  
Organic Matter ◽  
Feed Intake ◽  
Digestible Organic Matter ◽  
Ad Libitum

The liveweights and feed intakes of 409 adult wethers, from 2 pastoral sources, were measured in an experiment that simulated the assembly and shipping stages of the export of live sheep. The sheep were held separately with 17 wethers per group, and were introduced in outdoor yards to pelleted diets containing 0, 25 or 50% barley for either 5 or 9 days (adaptation) during which time lucerne hay or oaten hay were also fed. The wethers were then housed in intensive indoor pens (0.33 m21wether) for 14 days and fed the pelleted diets ad libitum without hay. During indoor feeding, wethers fed pellets containing 50% barley ate less pellets than did other sheep (1127 v. 1376 g DM/day, s.e.m. = 25.2, P<0.001). They had similar intakes of digestible organic matter (DOM) (732 v. 757 g/day, s.e.m. = 15.6), but lost more liveweight than did other sheep (- 1.88 v. -0.54 kg, s.e.m. = 0.200, P< 0.001). Increasing adaptation from 5 to 9 days significantly reduced the liveweight loss of wethers fed the diets containing 0% (-1.22 v. -0.20 kg, s.e.m. =0.283, P<0.05) and 25% barley (-1.35 v. 0.63 kg, s.e.m. = 0.283, P< 0.001) but had no effect on wethers fed diets containing 50% barley. Wethers fed lucerne hay during adaptation lost less liveweight indoors than wethers fed oaten hay (-0.66 v. -1.31 kg, s.e.m. = 0.163, P<0.01). Wethers fed lucerne for 9 days tended (P< 0.06) to eat more pellets indoors than other sheep (1386 v. 1262 kg, s.e.m. = 17.9). The wethers had an estimated intake of 37.9 g digestible organic matter/kg0.75 liveweight, which greatly exceeded expected requirements for maintenance and may be partly due to stress associated with intensive housing of the wethers.

Effects of season of growth and digestibility of herbage on intake by grazing dairy cows

1963 ◽  
Vol 5 (2) ◽  
pp. 119-129 ◽  
Author(s):  
J. L. Corbett ◽  
J. P. Langlands ◽  
G. W. Reid
Keyword(s):  
Organic Matter ◽  
Dairy Cows ◽  
Live Weight ◽  
Late Summer ◽  
Practical Experience ◽  
Digestible Organic Matter ◽  
Feeding Value ◽  
Grazing Dairy Cows ◽  
Maintenance Requirements ◽  
Strip Grazing

SUMMARY1. The intakes of herbage organic matter (OM) and digestible organic matter (DOM) by twenty dairy cows were measured during two periods of strip grazing on one pasture, in spring and late summer of the same year.2. Results from the first 5-day measurement period in the spring suggested that intakes at this time were restricted primarily because the cows had difficulty in gathering the short herbage. Measurements on ten of the cows continued during a further 5 weeks while the digestibility of the OM of grazed herbage declined from about 80 to 68%. There was a fall of about 20% in DOM intake by the cows during this period; one-quarter of the fall could be ascribed to a reduction in OM intake and the remainder to the decline in digestibility as such.3. Intakes were measured during two weeks in late summer and were compared with those measured during two weeks in the spring when the digestibility of the grazed herbage was similar. Intakes of DOM expressed as lb./lb. live-weight0·73 were the lower by about 10% in the late summer, or by from 10 to 20% in terms of DOM available for production when allowance had been made for maintenance requirements. This finding is discussed in relation to practical experience of the feeding value of autumn grass.

The utilization and excretion of sulphur in cattle fed on tropical roughages

1974 ◽  
Vol 25 (6) ◽  
pp. 1015 ◽  
Author(s):  
PM Kennedy
Keyword(s):  
Fatty Acids ◽  
Organic Matter ◽  
Dry Matter ◽  
Volatile Fatty Acids ◽  
Small Decrease ◽  
Heteropogon Contortus ◽  
Total Sulphur ◽  
Stylosanthes Humilis ◽  
Digestible Organic Matter ◽  
Townsville Stylo

The effect of additions of sulphateh to the diet of cattle given tropical spear grass (Heteropogon contortus) and Townsville stylo (Stylosanthes humilis) was studied in three experiments. In one experiment there was a small increase in the digestibility of dry matter, but the intake of feed was not affected. The concentration of volatile fatty acids in ruminal liquor from cattle offered spear grass was increased by supplemental sulphate; there was a concurrent small decrease in the proportions of propionic and isovaleric acids. Excretion of faecal sulphur varied with the intakes of total sulphur, organic matter, and digestible organic matter, while urinary sulphur excretion varied with the sulphur and organic matter intakes. Excretion of organic sulphur and total sulphate in urine and faeces increased with sulphur intake. The ratio of nitrogen to sulphur in faeces declined when sulphate was given. The retention of nitrogen was correlated with sulphur retention. It was concluded that the intake and digestion of the hays were not limited by the intake of sulphur.

The metabolic excretion and true digestibilities of nitrogen and fat by cattle and sheep with particular reference to forage-faeces relationships

1972 ◽  
Vol 23 (5) ◽  
pp. 879 ◽  
Author(s):  
KW Moir ◽  
AJ Swain
Keyword(s):  
Organic Matter ◽  
Nitrogen Excretion ◽  
Multiple Regression Equation ◽  
Detergent Solution ◽  
Dietary Nitrogen ◽  
True Digestibility ◽  
Digestible Organic Matter ◽  
Faecal Nitrogen ◽  
Digestible Protein ◽  
Cattle And Sheep

The non-dietary nitrogen excretion in faeces and the true digestibility of nitrogen determined in 23 digestibility experiments with grasses were respectively 0.60 ± 0.063 g N per 100 g forage organic matter and 84.9 ± 2.29%, when estimated from the regression of digestible nitrogen on percentage dietary nitrogen, and 0.60 ± 0.026 g N and 82.9 ± 2.33%, when estimated from data obtained by separating dietary and nondietary faecal nitrogen with detergent solution. The true digestibility of nitrogen, estimated similarly in four digestibility experiments with legumes, was higher than that in grasses. Among grasses and legumes but not within grasses, digestible organic matter was more closely correlated with non-dietary faecal nitrogen than with total faecal nitrogen. Among and within grasses and legumes the apparently digestible protein was more closely correlated with faecal nitrogen when undigested dietary nitrogen as a proportion of total faecal nitrogen was included as a variate in a multiple regression equation. The endogenous excretion of saponifiable fat was negligible and its average true digestibility estimated from regression analysis was 52. .6 ± 5.55 %.

Herbage as a source of digestible organic matter and digestible nitrogen for the grazing sheep.

1961 ◽  
Vol 12 (4) ◽  
pp. 689 ◽  
Author(s):  
JE Vercoe ◽  
DE Tribe ◽  
GR Pearce
Keyword(s):  
Organic Matter ◽  
Nutritional Value ◽  
Late Summer ◽  
Index Method ◽  
Nitrogen Intake ◽  
Digestible Organic Matter ◽  
The Mean ◽  
Grazing Sheep ◽  
Summer Minimum ◽  
Maintenance Requirements

An experiment is reported in which the digestible organic matter and digestible nitrogen intakes of Corriedale wethers grazing on improved pastures in a Mediterranean- type environment 1%-ere measured by the faecal index method from August 1957 to August 1958. The mean digestible nitrogen intake fell from a maximum of 50 g/clay in the spring to a minimum of 6 g/day in the late summer, and reached an autumn maximum of 13 g/day before falling to a winter minimum of 8 g/day. The mean digestible organic matter intake fell from a maximum of 1500 g/day in the spring to a summer minimum of 600 g/day, rose again to an autumn maximum of 1000 g/day, and fell again to a winter minimum of 600 g/day. The results are discussed in relation to the theoretical maintenance requirements of the sheep and the nutritional value of herbage.

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.

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