The feed intake of grazing cattle. II. The influence of size of animal on feed intake

Holmes, W.; Jones, June; Drake-Brockman, R. M.

doi:10.1017/s0003356100034048

Cited by 39 publications

(13 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Reid, Smith & Anderson (1958); 5, Wallace (1956); 6. Hutton (1962); 7, Corbett, Langlands & Boyne (1961); 8, Holmes, Jones & Drake-Brockman (1961).…”

mentioning

confidence: 99%

Utilization of the metabolizable energy of grass*

Blaxter

1964

Grass and Forage Science

View full text Add to dashboard Cite

A convenient way of measuring the energy which grass or indeed any food supplies to an animal is as its metabolizable energy. Metabolizable energy is defined as the heat of combustion of the food less the heat of combustion of the faeces, the urine and the combustible gas, mostly methane, which are produced from it. It is usually expressed as kcal metabolizable energy/g dry food and the definition is strictly in terms of measurable quantities, measurement of methane involving use of a respiration chamber. The calorific value of the dry matter of grass, or the organic matter of grass, is subject to relatively little variation. Hutton (1961, 1962), for example, found the calorific value of pasture grass to range from 4-32 to 4-56 kcal/g dry matter, a variation largely associated with the protein content of the grass. The main determinant of the metabolizable energy of grass per unit dry weight or per unit organic matter is undoubtedly the loss of energy in the faeces. Faecal losses of energy rarely fall below 15% but can rise to 60% of the heat of combustion of the grass. Loss of energy as methane rarely exceeds 10% of the energy of the grass and loss of energy in urine rarely exceeds 9% of the energy of the grass. Losses of energy both in urine and as methane vary over a considerably smaller absolute range than does the faecal loss of energy. Indeed, the metabolizable energy of grass and grassland products can be estimated with little error by multiplying the apparently digested energy of grass (heat of combustion of grass less heat of combustion of faeces) by 0-82. This factor applies to artificially dried grasses varying in protein content from 5-1 to 22-6% (Armstrong, Blaxter & Waite, 1964), to a dried lucerne (Bateman & Blaxter, 1964), to grass silages (J. L. Clapperton, 1963, unpublished) and to fresh pasture grass (Blaxter, Ekern & Sawers, 1963, unpublished). Alternatively, but with a slightly greater error, the metabolizable energy of grass can be estimated by assuming that each g digested organic matter has a metabolizable energy value of 3-6 kcal.Even so, such indirect methods of estimating metabolizable energy still involve a biological test in the form of a digestion trial. In our laboratory attempts have been made to estimate the metabolizable energy of grassland products from their chemical composition alone, commencing with a study of a series of artificially dried pasture grasses (Armstrong,

show abstract

“…Reid, Smith & Anderson (1958); 5, Wallace (1956); 6. Hutton (1962); 7, Corbett, Langlands & Boyne (1961); 8, Holmes, Jones & Drake-Brockman (1961).…”

mentioning

confidence: 99%

Utilization of the metabolizable energy of grass*

Blaxter

1964

Grass and Forage Science

View full text Add to dashboard Cite

show abstract

“…Calves usually showed lower faecal fibre and ash, and higher N concentrations than heifers or cows as reported elsewhere (Holmes, Jones and Drake-Brockman, 1961;Zoby and Holmes, 1983). Calves usually showed lower faecal fibre and ash, and higher N concentrations than heifers or cows as reported elsewhere (Holmes, Jones and Drake-Brockman, 1961;Zoby and Holmes, 1983).…”

Section: Animal Effectsmentioning

confidence: 68%

The influence of animal age and sward height on the herbage intake and grazing behaviour of Charolais cattle

Cazcarra

Petit

1995

Anim. Sci.

View full text Add to dashboard Cite

Mature dry cows, 18-month-old heifers and 7-month-old female calves of the Charolais breed (eight animals of each age) were strip-grazed on moderate (15cm) or tall (52 and 32cm) cocksfoot swards over two 15-day experimental periods. The swards were leafy regrowths of2 (short) and 8 (tall) weeks of age. Herbage intake was estimated by the alkane method, and grazing behaviour was visually recorded. Bite weight was lower, grazing time and biting rate greater, and organic matter in take of grass (OM1G) higher on shorter swards, the latter being related to a higher in vitro digestibility and nitrogen concentration. Average OMIG per kg live weight (M) was 15-2, 19-1 and 17-0 (s.e.d. 0-49)g in cows, heifers and calves respectively. The average allometric coefficient between , and close to that obtained with hay after the grazing trial-Faecal markers suggested a greater selectivity of calves compared with older cattle. Average bite weights (BW) were 310 (s.e. 40), 467 (s.e. 112) and 718 (s.e. 144)mg OM in calves, heifers and cows respectively. The allometric coefficient between BW and M was higher in short swards than in tall ones. Biting rates increased and grazing times tended to decrease with age of cattle.

show abstract

“…The overestimation as shown by the uncorrected values and attributed to selection by grazing animals has been reported by several workers. Corbett, Langlands & Reid (1963) reported an overestimation of 3-4 digestibility units; Holmes, Jones & Drake-Brockman (1961) found an overestimation of 4-7 units while Olubajo & Oyenuga (1970) reported a range of 4-6 digestibility units. The overall mean organic-matter intake varied from 5-67 ± 1-35 kg/head/day in treatment H to 6-42 ±1-60 kg; 6-59 ±1-08 kg and 6-51 ±0-66 kg/ head/day in.…”

Section: Discussionmentioning

confidence: 98%

“…intake of 2-71 % of live weight/ head/day for Panicum maximum. An organicmatter intake of approximately 6-1 kg/head/day by steers weighing approximately 220 kg on average, grazed on a pasture consisting of perennial ryegrass (Lolium perenne) and white clover (Trifolium repens) was reported by Holmes et al (1961), though the mean organic-matter digestibility (80 %) of the ryegrass/clover was much higher than those obtained in the present studies; this, and possibly the lower crude fibre content associated with temperate pastures, may partially account for the higher intake by the calves.…”

Section: Discussionmentioning

confidence: 99%

Pasture productivity in Nigeria: II. Voluntary intake and herbage digestibility

Oyenuga

Olubajo

1975

J. Agric. Sci.

View full text Add to dashboard Cite

The organic-matter intake and the digestibility of grazed tropical pasture mixtures were assessed by the chromic oxide-faecal organic matter-nitrogen technique in five digestion trials. The pasture treatments were designated as: H, Cynodon nlemfuensis var. robustus in a mixture with the legumes Centrosema pubescens and Stylosanthes gradlis; J, Pennisetum purpureum in a mixture with the two legumes in H; K, treatment J plus Panicum maximum; L, a mixture of all the grass and legume species in treatments H, J and K.The mean organic-matter digestibility of the herbages was determined in indoor digestion trials during the experimental period and varied from approximately 60-0+1-73% to 62-7 ±4-18% in treatments K and H respectively, with treatments J and L falling between these two values. The mean digestibility of the herbage as grazed, however, was approximately 66-8 ±1-72, 69-7 ±7-68, 67-1 ±4-40 and 67-4 + 4-15 % for treatments, H, J, K and L respectively.The estimated mean intake of organic matter was somewhat lower, while that of the digestible organic matter was appreciably lower than those reported for animals of corresponding live weights in temperate countries. Grazed pastures were better digested by 4-1 digestibility units in treatment H, by 7-1 in both J and K, and by 5-3

show abstract

The feed intake of grazing cattle. II. The influence of size of animal on feed intake

Cited by 39 publications

References 7 publications

Utilization of the metabolizable energy of grass*

Utilization of the metabolizable energy of grass*

The influence of animal age and sward height on the herbage intake and grazing behaviour of Charolais cattle

Pasture productivity in Nigeria: II. Voluntary intake and herbage digestibility

Contact Info

Product

Resources

About