ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1972.tb00677.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACTThree groups of Hereford × Friesian steer calves, bom in early January 1969, were strip‐grazed on eqoal areas of a sward of S321 perennial ryegrass from May to September inclusive, and received kibbled barley at the rate of nil, 3/4% or 1 1/2% of liveweight per day. Adjustments were made to the number of animals per group in order to maintain the same high grazing intensity (defined as 8 cm stubble height in grazed areas) on all treatments. The animals receiving supplementary barley gained weight at a rate 17–19% higher than the controls, but there was no significant difference in growth rate between the high and low levels of supplementation. The effficiency of conversion of barley was only 5–12 kg per animal liveweight gain/100 kg barley OM.The high level of supplementation resulted in an increase in stocking rate of 36 % over that of the control group, and an increase in liveweight gain per unit area of land grazed of 63%. The additional liveweight gain due to supplements, expressed per unit area of land grazed, was relatively constant at 21–24 kg liveweight gain/ 100 kg barley OM

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1972.tb00678.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACTThis paper describes experiments carried out with different depths of topsoil and methods of cultivation on an ash lagoon at Besthorpe, near Newark. Good yields of grass were obtained even on bare ash with suitable rates of fertilizer application. In the conditions existing at Besthorpe, the optimum depth of soil appeared to be three in. (7.62 cm), but the depth of cultivation (three in. (7.62 cm) or twelve in. (30.48 cm), die latter resulting in mixtures of soil and ash, had no significant effect.B uptake by the growing plants was markedly lower in the third year of the experiment but, apart from its possible effect on yield, it produced no ill effects.

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1972.tb00679.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACTThe rates of respiration in cut swards ofLolium perenne(S321) were measured while drying under simulated field conditions, the purpose of the experiment being to assess the extent of respiratory losses which can occur in the process of haymaking. Respiration measurements were made on the grass at different moisture contents during the drying process and also at different stages of growth. The results show that both the moisture content and the age of the grass had a significant infiuence on respiratory rates, consequently these factors can be expected to infiuence the DM losses which occur during haymaking. It was estimated that respiratory losses could amount to, at most, hetween 1.28 and 0.26 kg/100 kg DM, depending on the stage of growth at which the grass is cut

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1972.tb00680.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACTThe acid‐detergent fibre (ADF) contents of 50 grass samples of knownin vivoandin vitrodigestibility were determined by hydrolysing with acid for 1, 2, 3,4, 5, and 6 h. The 50 samples used consisted of 6Lolium perenne, 9 Cenchrus ciliaris, 15Chloris gayana, 10Digitariaspp., and 10Setariaspp. Regression and residual standard deviations (RSD) were calculated for each hydrolysis time for each grass and for all 50 samples.Increasing the hydrolysis time decreased the RSD forLolium perenneandSetaria, had no effect onChloris gayanaandDigitariaand increased the RSD forCenchrus ciliarisregressions. For regressions based on all 50 samples die RSD varied between ±4.8 and 5.0 digestibility units with only minor differences between hydrolysis times. Correcting the ADF for contaminating ash generally increased the RSD.Changing the acid strength from the 10 N recommended by van Soest (8) did not lead to any major improvement in the RSD for regressions based onCenchrus ciliaris, but withSetariathe RSD was reduced from ±2.8 to 1.7 digestibility units when 2N acid was used and hydrolysis was extended to 2 h.It was concluded that unless the optimum conditions for determining ADF for each grass are known then thein vitrotechnique provides digestibility estimates with a lower er

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1972.tb00681.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACTA coring technique (6), that may be used for estimating the mean amount of herbage on closely grazed pastures, has been adapted to include visual scoring. Two methods are described, both of which use sets of pasture cores from the sward as reference standards. The observers score the herbage on view at random sites against the standards. In the first method the scores are converted to herbage yields directly by reference to the yields of the standards. In the second method a double sampling regression technique is used and the set of standards is used as a visual guide only.

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1972.tb00682.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACTAutumn‐sown rye was cut on five dates in spring and ensiled in laboratory silos. On two of the dates forage‐harvested material was ensiled in PVC silos (containing about 1 t of fresh crop) as well as in laboratory silos. Ensiling was carried out with and without the addition of formic acid or glucose solution. After 96 days in laboratory silos, rye cut before ear‐emergence and ensiled without additives gave silages of high pH value and high ammonia content. After ear‐emergence satisfactory silage was produced without an additive, but the addition of formic acid always resulted in silages having lower pH values and lower ammonia contents. The addition of glucose resulted in silages with only slightly lower pH values and ammonia contents which were closely similar to those made without addition. Silages made in PVC silos were all well preserved, as indicated by low contents of acetic and butyric acids, but the addition of formic acid resulted in pH values and ammonia contents lower than those found in other tre

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1972.tb00683.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACTSoil samples were taken at 0–1 in. (0–2.54 cm) and 1–3 in. (2.54–7.62 cm) depths on five occasions over a period of 55 days from under (3 in. (7.62 cm) radius from centre) and around (9 in. (22.86 cm), 12 in. (30.48cm) and 18 in. (45.72 cm) radius from centre) dung patches deposited on pasture. The samples were analysed for available N, K and P. There was a significant increase in the level of all three elements in the 0–1 in. samples beneath the dung patch. The increase persisted throughout the experiment. K exhibited the greatest increase, but was not detected beyond the edge of the dung patch. The increase in soil N was smaller but was detected up to 6 in. (15.24 cm) from the edge of the dung patch. P also increased, but was more variable than either N or K. Soil N, P and K did not increase in the 1–3 in. samples.The weight and fibre content of the dung patch was also measured throughout the experiment. After high initial losses (25%) the dung patch decayed only slowly.The loss of ammonia from dung patches was followed over 13 days in a separate experiment During the relatively hot weather over this period approximately 5 % of the N iu the dung was lost as ammonia, mainly in the first five days. During the experimental period of 13 days 60% of the original weight of the dung patch was lost through evaporation.The results are discussed in relation to the growth of herbage surrounding a dung patch reported in the previous

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1972.tb00684.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACTResults from a field investigation indicated that dairy cows defaecated on average 13.9 times per day. Defaecations averaged 114 in.2(0.07 m2) in area and showed little difference in size in winter, spring and summer, although the cows defaecated significantly more often and dung consistency was less firm during the summer. The percentage area of paddock covered by dung patches after 24 hours' grazing ranged from 0.31% to 0.68%, depending principally on the stocking rate. Dung‐patch distribution over the paddock was uniform in spring and snmmer, but not in winter.The grazing pattern of two groups of dairy cows (blinkered and non‐blinkered) on a pasture containing dung patches was recorded over 4 days. Both groups exhibited a similar grazing pattern, suggesting that sight was not a primary aid to the selection of herbage. The resulte suggested that the smell of the dung patches was the primary cause for the rejection of the surrounding herbage.The results from this and the two previous papers are used to discuss the influence that the dung patch may have on the utilization of pasture by the grazing ani

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1972.tb00685.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1972.tb00686.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY