ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1978.tb00788.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1978.tb00789.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractForty British Friesian cows with a mean calving date of 28 January were used in a randomized block design experiment to evaluate a high‐quality grass silage for milk production. The high‐quality silage was made from two consecutive cuts of a perennial ryegrass sward after regrowth intervals of 37 days, wilted to 51% dry matter, finely chopped and ensiled using 2.2 1 t‐1(0.5 gallons per ton) of formic acid. The resulting silage had a dry matter digestibility of 72.9% and was fedad libitumwith 3.8 kg (8.4 lb) concentrates as a supplement. A medium‐quality grass silage, of lower digestibility and dry matter content (70.0 and 25.4% respectively), was also fedad libitumin addition to either 3.8, 5.7 or 7.6 kg (8.4, 12.5 or 16.7 lb) concentrates. The feeding treatments were commenced immediately after calving and were terminated on 9 April giving a mean period of 72 d on the treatments. Over the experimental period the animals on the high‐quality silage consumed 15% more silage dry matter and produced 8% more milk that those on the medium‐quality silage with the same level of concentrate supplementation. From the results it was estimated that 1.9 kg (4.3 lb) of additional concentrates would be required with the medium‐quality silage to give an equivalent milk output to that achieved with the high‐quality silage. Milk composition, liveweight change, ration digestibility and nitrogen balance data are

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1978.tb00790.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractSeventy‐three samples of grass and legume herbage of knownin vivodigestibility were used to compare anin vitroprocedure comprising incubation with pepsin followed by cellulase (Jones and Hayward, 1975) with the Tilley and Terry (1963) procedure using rumen liquor followed by pepsin. The results obtained using the pepsin‐cellulase method proved to be highly repeatable. On the basis of the residual standard deviation of the regression ofin vivodry matter digestibility (DMD) on dry matter digestedin vitro(g/100 g DM), the pepsin‐cellulase method was shown to be only slightly less accurate than the rumen liquor‐pepsin method for combinations of both primary growth and regrowth of grasses (r.s.d. ±1.80 and ±1.46 respectively). However, the pepsin‐cellulase method was noticeably less accurate than the rumen liquor‐pepsin method when used on legume herbages (r.s.d. ±3.17 and ±1.91) or on grass and legume herbages combined (r.s.d. ±3.80 and ±1.60). For the rumen liquor‐pepsin method one regression equation predicting DMD having the form,Y= 1.02X−0.41, was permissible. For the pepsin‐cellulase method separate regression equations were necessary for grasses (species and growth stages combined) having the form,Y =0.56X+34.7, and for each legume species. It was concluded that the pepsin cellulase method was of value for grass samples, and, within species, for legumes because of its accuracy and precision and its speed and convenience relative to the rumen liquor‐pepsin procedure; however, for legume species combined, and presumably for grass‐legume mixtures, it wa

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1978.tb00791.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractMaize silages made in October were fed to forty‐three autumn‐calving cows during a 20‐week winter feeding trial. The control silage received no additive whereas a non‐protein nitrogen (NPN) additive was applied to the other silage at harvest time. The four experimental feeding treatments were: A, maize silage + 6 kg d−1barley; B, maize silage with NPN + 6 kg d−1barley; C, maize silage + 5 kg d−1’barley + 1 kg d−1extracted decorticated groundnut cake; D, maize silage with NPN. The mean daily milk yields of cows on the treatments were 14.7, 15.1, 15.3 and 15.0 kg respectively. All cows received maize silagead libitum. There were no significant differences in milk yield but the milk produced by the cows on treatment D had significantly lower concentrations of milk fat, protein and solids‐not‐fat when compared to the other three treatments. The cows on treatment D had a negative liveweight change which was significantly different (P<0.05) from those of the cows

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1978.tb00792.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractDalapon (2.8 kg ha×1) was applied in July, either annually or biennially, to a sown sward that contained about 50%Lolium perennemeasured on a ground cover basis. The sward was grazed with young beef animals at three stocking rates throughout the 4 years of the experiment.In unsprayed plots, the proportion ofL. perennedeclined to less than 20% (30, 14 and 16% on high, medium and low stocking rates respectively).Lolium perennewas replaced largely byHolcus lanatusandPoaspp. Annual applications of dalapon checked the decline inL. perenne. After 4 years of annual treatment with dalapon, 44%L. perennewas present on heavily stocked plots, 41% on medium stocked plots and 26% on lightly stocked plots. Biennial applications of dalapon had slightly less effect on the proportion ofL. perenne. The proportion ofTrifolium repensin the sward was affected by dalapon and stocking rate in much the same way as that ofL. perenne.Monthly cattle weights showed that dalapon caused a slight check to individual animal performance in the month after spraying, but total liveweight gain per unit area was not significantly affected. Increasing stocking rates were inversely related to performance per animal and directly related to output per unit area. Dalapon × stocking rate interactions were generally non‐significant. There was a slight tendency for higher animal gains to be associated with higher proportions ofL. perenne, but this only held for the first half of the growing season. Mean maximum liveweight gain of about 1000 kg ha−1was achieved in 1974, by which time the proportion ofHolcus lanatushad risen to a mean value of nearly 40%. The value of indigenous grasses for summer beef production is disc

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1978.tb00793.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractThe relationships between, and changes in moisture content, 1000‐seed weight, germination percentage and seed yield were determined from anthesis onwards in ten amenity grasses in 1975. These relationships were used to indicate the optimum date for combine harvesting and to give some indication of the consequences which follow if harvest was not carried out at this stage.In all species seed moisture content declined, and 1000‐seed weight and germination increased to a maximum value, during ripen

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1978.tb00794.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractBetween 1967 and 1975, 416 beef animals were grazed rotationally on an indigenous pasture (11.65 ha) containingFestuca rubra, Holcus lanatus, Poa trivialisandAgrostisspp. and dicotyledonous plants, but littleLolium perenneorTrifolium repens. Part of the land received fertilizer nitrogen at rates varying between 120 and 200 kg h−1each year and part did not; some of the land was grazed only and some was cut and then grazed.The winter gains of the animals (approx. 45 kg) were more variable and less than the summer gains (approx. 155 kg). Summer gain was inversely correlated with winter gain. An increase in initial weight of animals purchased from 1973 onwards did not increase either winter or summer gain. Friesians gained more than Hereford‐cross animals during the winter, but there was no difference in summer gain.During 9 years the average animal weight per grazed ha in April was increased from 1260 to 2122 kg. The mean total gain on 1165 ha of grass was 6486 kg per annum in the first 3 years and 7266 kg per annum in the last 3 years. The average annual production was 590 kg live‐weight gain and 1.01 t hay or 2.33 t silage per ha. The output of fertilized grass in 1975 was calculated as 842 Livestock Unit Grazing Days (LUGD) per ha and that from unfertilized grass as 360 LUGD per ha. The overall output of utilized metabolizable energy in 1975 was 59–7 GJ h−1, with 69.3 GJ h−1from fertilized grass and 29.8 GJ h−1from unfer

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1978.tb00795.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractSingle plants of white clover (Trifolium repens) were subjected either to two intensities of overall defoliation or to severe defoliation of different parts of the plant. Measurements were made of growth in terms of leaf size, petiole length, internode length and other parameters, and compared with those of undefoliated plants. The results show that, while growth of all parts of the plant was reduced by severe overall defoliation, partial defoliation affected various parts of the plant differently according to which leaves were removed. The results are interpreted in terms of the acropetal movement of assimilates from alternative sources in response to defoliation.The probable effects of this on yield and its relevance to grazing management of newly seeded clover are discussed.

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1978.tb00796.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractA method for determining the extent of fertilizer interception by plants is described. Regression models were developed from the data collected. Dry matter was found to be a convenient and satisfactory pasture parameter to use for the prediction of fertilizer interception.

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1978.tb00797.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY