The effects of grazing intensity on herbage consumption and animal production: III. Dairy cows grazed at two intensities on clean or contaminated pasture

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.

1972 ◽  
Vol 78 (3) ◽  
pp. 491-496 ◽  
Author(s):  
G. W. Reid ◽  
J. F. D. Greenhalgh ◽  
J. N. Aitken

SUMMARYFor phase I of a rotational grazing experiment (three grazing cycles; May–July) a group of nine cows (group S) were ‘conditioned’ to eat fouled herbage by being allowed to graze only on slurry-treated pasture (area 1), and two further groups of nine (groups H and C) grazed on an adjacent area (2) of untreated pasture. One-third of area 2 was harrowed after each grazing. During phase II (the fourth grazing cycle; August) group H grazed on the harrowed part and groups S and C grazed on the remainder of area 2. The herbage allowance was 15 kg dry matter per cow per day in phase I and 12 kg in phase II.In phase I, group S cows ate significantly less than groups C and H combined (9·2 v. 10·5 kg organic matter per day), and lost weight (– 0·37 v. + 0–03 kg/day), but their milk yields were not significantly lower (16·1 v.16–6 kg/day). In phase II neither intake nor milk yield differed significantly between the three groups, but group S cows gained weight while the other two groups lost weight.It was concluded that neither conditioning the cows nor harrowing the pasture was an effective means of avoiding rejection of fouled pasture.


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.


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.


1981 ◽  
Vol 33 (2) ◽  
pp. 199-209 ◽  
Author(s):  
R. Laird ◽  
J. D. Leaver ◽  
F. R. Moisey ◽  
M. E. Castle

ABSTRACTNinety-six lactating British Friesian cows were offered ad libitum two grass silages having the following analyses: 181 and 241 g dry matter per kg fresh weight, 108 and 96g digestible crude protein per kg dry matter and 617 and 619 g digestible organic matter per kg dry matter. In addition, four concentrate supplements were offered, containing either 360 g crude protein per kg on an air-dry basis and given at the rate of 015 kg/kg milk or 180 g crude protein per kg given at the rate of 030, 0375 and 0·45 kg/kg milk. Large and highly significant differences were recorded in silage intake, mil yield, milk composition, live weight and condition score during the winter feeding period. These differences in performance were associated more with differences in energy than in protein intake. During the post-experimental grazing period no significant differences between treatments were recorded in milk yield and composition, with the exception of fat concentration, and by midsummer no significant differences were apparent in live weight. The results of the experiment were appraised in economic terms and implications for commercial practice discussed.


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.


1979 ◽  
Vol 29 (2) ◽  
pp. 163-173 ◽  
Author(s):  
K. Aston ◽  
S. R. Daley ◽  
J. C. Tayler

ABSTRACT1. Thirty lactating British Friesian heifers and cows were individually given maize silage ad libitum containing 331 g dry matter/kg, 13 g nitrogen and 11·2 MJ of metabolizable energy per kg dry matter. Urea or aqueous ammonia was mixed in at the time of feeding to give 7·0 g nitrogen per kg silage dry matter. Urea-treated silage was given with concentrates at a high (mean 6·6 kg dry matter/day: treatment HU) or a low (mean 3·3 kg:treatment LU) level of feeding; the lower level only was given with ammonia-treated silage (treatment LA).2. The addition of ammonia raised silage pH values from 3·9 to 4·4. Silage dry-matter intakes in lactation weeks 7 to 22 for treatments HU, LU and LA were 8·8, 11·1 and 10·7 kg/day.3. Digestible organic matter content in the dry matter of the diets measured in vivo was not significantly affected by treatment. However, digestible organic matter intakes were significantly greater for treatment HU than for LU in weeks 7 to 10, and for LU than for LA in weeks 11 to 22.4. The yields of milk and the contents of protein, lactose and energy did not differ between treatments. The milk yields for treatments HU, LU and LA in weeks 7 to 22 were 20·2,19·2, 18·8 kg/day respectively. Fat content of milk was significantly depressed with the HU treatment for heifers in weeks 7 to 10. The live-weight changes of the cows in weeks 7 to 22 for treatments HU, LU and LA were +0·10, −0·07 and −0·37 kg/day; the live-weight loss by cows given treatment LA was significantly greater than for LU. The live-weight change of the heifers was not affected by treatment.


1983 ◽  
Vol 36 (1) ◽  
pp. 143-146 ◽  
Author(s):  
A. Moore ◽  
C. Harris

ABSTRACTOne hundred tonnes of spring-sown barley harvested as whole crop were treated on a commercial farm with pearl sodium hydroxide at 46 g/kg dry matter.The treated material was stored in a silage clamp beneath grass and lucerne silage. A thin layer of grass, cut and wilted to hay-making dry matter, was placed immediately on top of the barley to absorb any silage effluent.Monthly samples were taken for microbiological examination and chemical analysis throughout winter storage, while the material was fed to British Friesian dairy cows. There was no evidence of fermentation by clostridia in the whole-crop barley or wilted grass and there was no spoilage of the exposed feeding face. The treatment increased the in vitro organic matter digestibility and the in vitro digestible organic matter in the dry matter of the whole-crop barley. No excessive urination or other ill effects were observed in the stock.The method proved practical for the satisfactory storage and feeding of sodium hydroxide-treated whole-crop barley.


Author(s):  
S.L. Woodward ◽  
A.V. Chaves ◽  
G.C. Waghorn ◽  
P.G. Laboyrie

Forages suitable for supplementing pasture-fed dairy cows over summer-autumn must provide adequate dry matter (DM) and increase milk yield above that produced by cows grazing normal ryegrass/white clover pasture, without compromising milk composition. A trial was conducted in January-February 2001 to compare the benefits obtained from feeding four types of silage. There were two silages that contained condensed tannins (CT) (birdsfoot trefoil (Lotus corniculatus) and sulla (Hedysarum coronarium)), maize silage or traditional ryegrass-dominant pasture silage, all fed at 5 kg DM/cow/d with restricted pasture. Cows on the restricted pasture (control) treatment and those fed the silage treatments were offered an allowance of 25 kg DM pasture/cow/d, while the full pasture cows were offered 50 kg DM pasture/cow/d. Silage supplementation, regardless of silage type, increased both total dry matter intake (DMI) and milk production compared with the restricted pasture treatment. Cows on the Lotus silage supplement, and the full pasture treatment had significantly higher milk yields than the other silage-supplemented cows, all of which had similar milk yields. For the Lotus silage treatment, the high milk yield was probably due to a combination of the higher nutritive value of the silage, and to the action of CT, because the total DMI of the cows on the Lotus silage was the same as that of cows on the pasture silage and maize silage. The high milk yield of the full pasture treatment was mainly a result of the cows having a significantly higher total DMI than cows on all the other treatments. This trial has demonstrated the potential benefit of silage supplementation, particularly with Lotus silage, for increased milksolids yield in summerautumn when low pasture growth rates and quality may otherwise limit production. Keywords: condensed tannins, dairy cows, Lotus, maize, milksolids, ryegrass, silage, sulla, supplementation


1975 ◽  
Vol 20 (3) ◽  
pp. 345-353 ◽  
Author(s):  
R. Marsh

SUMMARYFour experiments were carried out with calves offered pellets containing different ratios of cereal/protein concentrate and dried grass together with 10% chopped hay. Organic matter digestibility of total ration declined by 5·2 percentage units for each 25% increment of dried grass.Dry matter (DM) intake of the total ration increased as dried grass content increased from 0 to 50% which led to similar intakes of digestible organic matter (DOM) and daily gain. When pellets contained 75% dried grass, total DM intakes were reduced in two experiments, leading to DOM intakes and daily gains similar to that of calves offered pellets of dried grass only. In the third experiment, DM intake of pellets containing 75 % dried grass was greater than the intake of pellets containing 50 to 100 % dried grass. When equal quantities of DM were offered, DOM intakes and daily gains tended to decline linearly as dried grass content in the pellet increased. The replacement value of the dried grass for concentrate at equal levels of live-weight gain was 1·36: 1.


1977 ◽  
Vol 25 (3) ◽  
pp. 397-400 ◽  
Author(s):  
M. E. Castle ◽  
W. C. Retter ◽  
J. D. Metcalfe

SUMMARYGrass silage with a dry-matter content of 20·7%, and containing 18·9% crude protein and 67·0% digestible organic matter in the dry matter was self-fed to 20 lactating dairy cows for 18 weeks. In addition, 9 kg of brewers' grains with a dry-matter content of 28·8% was offered to each cow daily. The two supplement treatments were a barley mix and a groundnut cube containing 11·9 and 33·5% crude protein in the dry matter respectively. The barley was given at the rate of 4 kg/10 kg milk, and the groundnut at 1·5 kg/10 kg milk. The mean daily yields of milk were 18·9 and 19·4 kg/cow on the barley and groundnut treatments respectively and did not differ significantly.


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