Journal ArticleDOI
The utilization by beef cattle of concentrate diets containing different levels of milled barley straw and of protein.
TLDR
An experiment to study the utilization by beef cattle of high concentrate diets containing different amounts of milled barley straw and of protein found that food conversion ratio, expressed as total dry matter consumed per kg live-weight gain, tended to increase with increasing proportion of straw in the diet.Abstract:
Summary 1. An experiment consisting of two separate trials was carried out to study the utilization by beef cattle of high concentrate diets containing different amounts of milled barley straw and of protein. For each trial twenty-four Friesian steers, initially weighing about 270 kg, were divided into three groups and the animals within each group then allocated at random to eight dietary treatments. The treatments were based on an all-concentrate diet and three others containing 10, 20 and 30% of milled (1 in screen) barley straw. Four of the treatments consisted of giving the same concentrate mixture with each level of straw, and the other four involved giving concentrate mixtures with increasing levels of protein so that the percentage of protein in the diets was maintained. All the diets were fed ad libitum until slaughter. 2. Performance in terms of live-weight gain was considered as the net result of a number of factors, notably the total intake of dry matter, the digestibility of the dry matter, the efficiency of utilization of the end products of fermentation in the rumen and the composition of the live-weight gain. The inclusions of 20 and 30% of straw in the diet were associated with lower rates of gain than on corresponding all-concentrate and 10% straw treatments but the differences obtained did not attain significance. Total intakes of dry matter were greater on treatments containing 10 and 20% of straw than on corresponding all-concentrate treatments, but then declined with further increase in level of straw to 30%. This trend was significantly curvilinear (P < 0·01), the equation for the relationship being Y = 5·881 + 0·131X - 0·004X2, with Y being the daily intake of dry matter (kg) and X the percentage of straw in the diet. The maximum intake of dry matter was calculated to occur with a level of 16·4% straw in the diet and represents an increase in total dry matter intake of 18·2% over that on an all-concentrate diet. Food conversion ratio, expressed as total dry matter consumed per kg live-weight gain, tended to increase with increasing proportion of straw in the diet. 3. The mean digestibility of organic matter fell sharply with the inclusion of 10% straw in the ration, the decrease being 8·2% where the protein level was not maintained and 9·1% where it was maintained. Further reductions in digestibility occurred on the 20 and 30% straw diets, but the magnitude of the reductions were considerably less than those brought about by the initial introduction of straw into the ration. 4. The molar percentage of acetic acid in the steam volatile acids of rumen liquor increased markedly, and that of propionic acid decreased sharply from the all-concentrate to the 10% straw treatment with a similar level of dietary protein. Increase in the level of straw to 30% gave rise to a further increase in the proportion of acetic acid and reduction in that of propionic acid. Analysis of samples taken at 3, 6, 9 and 12 h after feeding showed appreciable differences in pattern between treatments. 5. Effects of treatment on killing-out percentage were different for each trial. In trial 1 the inclusion of straw in the diet did not cause any reduction in killing-out percentage, but the maintenance of protein level gave rise to a significantly higher killing-out percentage than was obtained with the lower protein groups. In trial 2 the killing-out percentages showed a significantly linear (P < 0·01) decrease with increasing proportion of straw in the ration, and maintenance of protein level did not give any improvement.read more
Citations
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Journal ArticleDOI
Diet selection in sheep: the ability of growing lambs to select a diet that meets their crude protein (nitrogen × 6.25) requirements
Ilias Kyriazakis,J. D. Oldham +1 more
TL;DR: The results suggest that sheep were able to select a diet that meets their CP requirements and avoid, at least to a certain extent, excess of protein intake.
Journal ArticleDOI
The digestibility and acceptability to sheep of chopped or milled barley straw soaked or sprayed with alkali
TL;DR: The main objective of the experiments described was to compare the effects of milling straw and/or soaking or spraying it with sodium hydroxide on its digestibility and acceptability to sheep.
Book ChapterDOI
Protein–energy interrelationships for growing and for lactating cattle
J.D. Oldham,T. Smith +1 more
TL;DR: To establish the nature of responses to protein supplements, especially with a view to developing new protein feeding systems, it would be helpful if feeding trials were always supported by in vivo measurements of digestibility.
Journal ArticleDOI
The influence of supplements of energy and protein on the intake and performance of cattle fed on cereal straws
TL;DR: In two experiments the effects of several levels of supplementary energy and of protein on the voluntary intake of long straw by young cattle of 200 to 300 kg weight were studied.
Journal ArticleDOI
Rumen degradation of straw 6. Effect of polysaccharidase enzymes on degradation characteristics of ensiled rice straw
TL;DR: In this article, the effects of polysaccharidase inclusion level (0, 5 and 10 g/kg), moisture content (500, 600 and 700 g/ kg dry matter (DM), and particle size (20, 5, 2 mm) on the quality and degradation characteristics of rice straw were investigated.
References
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Journal ArticleDOI
Volatile Fatty Acid Analyses of Blood and Rumen Fluid by Gas Chromatography
E.S. Erwin,G.J. Marco,E.M. Emery +2 more
Journal ArticleDOI
Suction Strainer Technique in Obtaining Rumen Fluid Samples from Intact Lambs
Ned S. Raun,Wise Burroughs +1 more
Journal ArticleDOI
Studies on the nutrition of ruminants. I. Substitution of maize by milled barley straw in a beef fattening diet and its effect on performance and carcass quality
Journal ArticleDOI
Studies on the nutrition of ruminants. II. The effect of level of crude fibre in maize-based rations on the carcass composition of Friesian steers
H. Swan,G. E. Lamming +1 more
Journal ArticleDOI
Studies on the nutrition of ruminants. 4. The use of ground straw of different particle sizes for cattle from twelve weeks of age.
TL;DR: Friesian calves fed from twelve weeks of age on six diets containing 15 or 30% ground barley straw had mean growth rates of 1·15 kg/day with a feed conversion ratio of 4·15: 1, and differences between stages of fattening were highly significant.
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