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

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.

1969 ◽  
Vol 72 (2) ◽  
pp. 223-228 ◽  
Author(s):  
J. F. D. Greenhalgh ◽  
G. W. Reid

SUMMARYOn three occasions in May—July one half of a ryegrass pasture was grazed intensively by cattle and the other was mown. In August and September these areas, designated fouled (F) and clean (C) respectively, were each strip-grazed by two groups of five cows. One group on each area had a herbage allowance of 11·4 kg dry matter per cow per day (C11 and F11) and the other 20·4 kg (C20 and F20).Before the August-September grazing the fouled area had 2·8% of its surface covered by faeces. After this grazing 23 % of the F n area and 34 % of the F20 area were classified as having been rejected by the cows. However, the upper parts of the sward on these rejected areas were in fact grazed. There were only small differences in N and soluble-carbohydrate contents between the herbages offered and rejected.Organic-matter digestibility (%) and intake (kg/cow per day) for the four groups were: C11, 73·0 and 10·5; C20, 74·9 and 11·7; F11 , 74·4 and 9·6; F20, 77·0 and 10·6. The C11 cows consumed all the herbage allowed to them, but the F11 rejected 13%. Digestible organic matter intake was affected more by grazing intensity than by fouling; this was the case also for milk yield, milk composition and the live-weight change of the cows.


1961 ◽  
Vol 12 (4) ◽  
pp. 689 ◽  
Author(s):  
JE Vercoe ◽  
DE Tribe ◽  
GR Pearce

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.


1968 ◽  
Vol 71 (3) ◽  
pp. 343-349 ◽  
Author(s):  
J. M. Doney ◽  
A. J. F. Russel

SUMMARYIn a series of experiments, each of 6 weeks' duration, non-pregnant Romney, Scottish Blackface and Tasmanian fine-wool Merino ewes were individually penned in an outdoor environment and allocated a constant ration within a range from 8 to 30 g of a standard dried-grass pellet per kg live weight. Maintenance requirements were calculated from the regression of live-weight change per unit weight on intake per unit weight. Comparable values for the three breeds were computed as 8·4, 9·2 and 14·0 g DOM (digestible organic matter)/kg/day for Romney, Blackface and Merino respectively, the latter being significantly higher than for the two British breeds. Estimates of requirements per unit change in live weight, after allowing for maintenance, were 5·1, 4·6 and 3·0 g DOM/g live-weight change for the three breeds. Methods of estimation of energy requirements and the reasons for differences between breeds are discussed.


1975 ◽  
Vol 84 (2) ◽  
pp. 373-376 ◽  
Author(s):  
R. A. Terry ◽  
M. C. Spooner ◽  
D. F. Osbourn

SUMMARYThe digestibility and intake by sheep of a neutral mixture of alkali-treated straw and grass silage was compared with an all-silage diet, mixtures of treated straw and silage adjusted to pH of 4 and 10 and with mixtures of untreated straw and silage. Treatment of the straw with alkali increased the digestibility of the organic matter from 46% to 68%. The daily intake of dry matter and digestible organic matter of the neutral, treated-straw/silage mixture was 24·1 and 15·0 compared with 14·7 and 8·8 g/kg live weight for the untreated straw/silage mixture. The sheep when fed ad libitum ate more of the neutral mixture than they did of the mixtures made acid (pH 4·0) and alkaline (pH 10·0) or of the grass silage although the differences were not significant. Calves were fed similar diets of grass silage, a neutral mixture of treated straw and silage and treated straw and grass silage offered without premixing. The calves offered the neutral mixture ate 16·0% more dry matter and 14·5% more organic matter than did the calves offered either silage alone or the unmixed diet and gained live weight at the rate of 0·42 kg/head/day compared with 0·44 for the silage alone and 0·37 for the unmixed diet.


1967 ◽  
Vol 69 (2) ◽  
pp. 217-223 ◽  
Author(s):  
J. F. D. Greenhalgh ◽  
G. W. Reid ◽  
J. N. Aitken

1. The object of the experiment was to determine the effects on the diet and production of grazing dairy cows of providing different quantities of herbage over a relatively long period.2. Three groups of five Ayrshire cows were strip grazed on areas supplying (A) 25, (B) 35 or (C) 45 lb D.M. per cow per day, for a total of 11 weeks. Three swards were used in succession, and measurements of herbage intake, milk production and live-weight changes were made over the last 10 weeks.3. Mean intakes for treatments A–C, respectively, were 23·9, 25·6 and 26·4 lb organic matter per cow per day, and milk yields were 30·4, 30·8 and 32·8 lb. Differences in digestibility between treatments were small, even when the cows grazed poor herbage in which the organic matter was only 68 % digestible.4. The treatments had no significant effects on milk composition or live-weight gain, although the latter was less for treatment A.


1990 ◽  
Vol 114 (1) ◽  
pp. 49-54 ◽  
Author(s):  
G. J. Cruickshank ◽  
D. P. Poppi ◽  
A. R. Sykes ◽  
A. S. Familton

SUMMARYThe voluntary food intake, in vivo digestibility and site of nutrient digestion was measured in 12 Polled Dorset ram lambs, from 6 to 24 weeks of age, offered clover hay. Lambs were weaned at 6 weeks of age. Six were fitted with a permanent T-shaped cannula in the abomasum and a temporary rumen catheter during the periods of digesta flow measurement.Surgical modification of lambs did not influence intake (g/kg live weight (W) per day), in vivo digestibility or marker retention time in the rumen. However, intact lambs grew significantly faster than cannulated lambs (139 v. 109g/day, P < 0·05) apparently because of an overall higher cumulative intake over the whole experimental period rather than any change in efficiency of use of nutrients or maintenance requirement.Relative to live weight, intake increased rapidly until c. 10 weeks of age and remained relatively constant at c. 37 g DM/kg W per day for the remainder of the experiment. Age had no effect on in vivo digestibility of organic matter (OM) or neutral detergent fibre (NDF) (average 0·69).The proportion of digestible organic matter apparently digested in the rumen (DOMADR) decreased from 0·63 to 0·47 between 8 and 24 weeks of age whilst intake between these measurement periods increased. Nonammonia N (NAN) flow past the abomasum was similar at all ages in relation to digestible organic matter intake (55·1 g NAN/kg DOMI) but was higher at 16 and 24 weeks of age than at 8 and 12 weeks of age, respectively, in relation to organic matter apparently digested in the rumen (OMADR) (116 and 85 g NAN/kg OMADR, respectively, P < 0·05).Fractional outflow rate of digesta markers from the rumen, when estimated from abomasal digesta, was significantly higher than when estimated from faeces (103Ru-p 0·121 v. 0·09; 51Cr-EDTA 0·169 v. 0·111/h; P > 0·05).It was concluded that cannulation did not affect intake and digestion characteristics in these young lambs. The changes in the site of nutrient digestion as the animals aged may have been due to agerelated changes in digestive function but appeared to be associated with the increase in intake that occurred between measurement periods of the cannulated lambs.


1986 ◽  
Vol 107 (1) ◽  
pp. 43-54 ◽  
Author(s):  
Lindsey Caird ◽  
W. Holmes

SUMMARYInformation on the total organic matter intake, concentrates supplied (C), live weight (LW), week of lactation (WL), milk yield (MY), herbage organic matter digestibility (HOMD), herbage mass, sward height (SHT) or herbage allowance (HAL) measured individually for 357 cows at one of three sites was assembled. Observed intake was compared with intakes predicted by existing intake equations and new prediction equations based on regression models or regression and least-squares constants were developed. Major factors affecting intake were MY, LW, WL, C and HAL or SHT. Although HOMD was correlated with intake, better predictions were obtained when HOMD was omitted. There were differences between sites possibly associated with differences in measurement techniques.The predictive value of some existing equations and new equations were tested against independent sets of data. A simple equation (A) based on MY and LW (Ministry of Agriculture, Fisheries and Food, 1975) gave satisfactory average predictions but the mean square prediction error (MSPE) was high. The equations of Vadiveloo & Holmes (1979) adjusted for bias gave a relatively low MSPE. The preferred new equations for grazing cattle included MY, LW, WL, C and HAL or SHT, and their MSPE were similar to or lower than for indoor equations.The discussion indicates that a simple equation (A) would give adequate predictions for farm planning. The more detailed equations illustrate the inter-relations of animal with sward conditions and concentrate allowances. Predicted intakes may deviate from actual intakes because of short-term changes in body reserves.


1946 ◽  
Vol 36 (3) ◽  
pp. 222-225
Author(s):  
G. H. N. Pettit

The general characteristics of a group of thirtynine herds of dairy cows in the Eastern Counties of England, and the method of obtaining information about their diet during the winters 1938–9 to 1942–3 inclusive, are briefly described.The first three winters of the war show a continuous decline in starch equivalent and protein equivalent per cow, followed by a recovery during winter 1942–3.Comparing winter 1942–3 with winter 1938–9: Consumption per cow of concentrates declined by one-third, reductions in proprietary compounds and mixtures and in maize and wheat products being outstanding.The more important increases were in oats, straw and succulent foods, notably mangolds, sugar-beet tops and kale.Hay retained its important place with little overall change; a modest increase in silage was restricted to a few herds.The crude weight of the average daily ration increased from 44 to 61 lb., but its dry matter only from 21·0 to 22·6 lb.The residue: total dry matter less digestible organic matter—increased from 7·2 to 8·4 lb. per cow daily. Reference is made to changes in palatability.


1963 ◽  
Vol 5 (1) ◽  
pp. 11-16 ◽  
Author(s):  
J. P. Langlands ◽  
J. L. Corbett ◽  
I. McDonald ◽  
G. W. Reid

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.


Author(s):  
A. Hargreaves ◽  
J.D. Leaver

It is not clear when the optimum time of harvesting the winter barley as whole crop for silage should be in terms of feeding value for dairy cows and yield of the crop. Little information is available using whole crop barley as a buffer feed. The aim of these experiments was to evaluate the feeding value of whole crop barley (WCB) silage harvested at three stages of growth as a supplementary feed for grazing dairy cows during the late season.Winter barley (var. Pipkin) was harvested at 4 stages of growth : T1:250, T2:350, T3:450 and T4:550 gDM/kg, at the following dates : 25/5, 19/6, 3/7 and 11/7/1991, respectively. The chopped material from T1-T4 was stored in minisilos and from T1-T3 in larger silos for animal studies.


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