摘要:

ABSTRACTA total of 228 separate dung pats voided by lactating dairy cows between May and October on a ryegrass/dover sward were studied for 2 years. The pats were on grazed swards receiving, on average, either 440 or 110 lb N/ac (492 or 123 kg/ha) per year. The mean area of the pats was 0.62 ft2(0.058 m2) with no difference in area between the pats on the two N treatments. On average, the pats on the high‐ and the low‐N treatments crumbled in 63 and 55 days, respectively, and disappeared in 115 and 113 days, respectively. Pats deposited in July disappeared significantly quicker than pats deposited in May. The average area of rejected herbage around the pats was 2.63 and 084 ft2(0.244 and 0.078 m2), respectively, 1–2 months, and 1 year after they were voided; but after 2 years the affected areas were recolonized with ryegrass and clover and were grazed normally. It is concluded that the levels of N fertilizer applied had no differential effects on the breakdown of the dung and on the subsequent recolonization of the affected areas by pasture p

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1972.tb00700.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACTCu‐enriched pig‐mannre slurry was applied to grassland at two rates, 5000 and 10,000 gal/ac (56,000 and 112,000 I/ha), on three occasions, supplying a total of 5.4 Ib/ac (6.1 kg/ha) and 10.8 Ib/ac (12.2 kg/ha) Cu, respectively. At the higher rate, soil Cu extractable with EDTA increased from 24 ppm to 7.3 ppm Cu in samples taken to a depth of 3 in. (7.5 cm) and Cu in herhage DM increased from 9.1 ppm to 21.2 ppm Cu (mean of 5 cuts). Much of the additional Cu in the herhage was thought to be derived from external contamination. In other tests, leafy herbage sampled a few hours after applying slurry contained 338 ppm Cu in the DM.Samples of soil and herbage were taken in 1969, 1970 and 1971 from farm grassland that had received Cu‐enriched pig‐manure slurry each year; levels of Cu increased in the soil, Cu levels in herbage were variable and appeared to be affected by the rate of grass growth.The evidence suggests that there is at present littie risk of Cu toxicity following applications of Cu‐enriched pig‐manure slurry; the greatest risk to susceptible stock would appear to be by ingesting either grazed or conserved herbage contaminated with slurry. To avoid possible hazards from a build‐up of Cu in the soil, a maximum annual application of ahout 8.5 Ib/ac (9.5 kg/ha) Cu is suggested until more is known on the availability of Cu in slurry to cr

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1972.tb00701.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACTA grazing experiment using four stocking rates of sheep, equivalent to 34, 45, 57 and 68 sheep/ha on an assumed 200‐day grazing season, was conducted using a portable grazing corral technique. Plots were subjected to fotir grazing periods between mid May and early September. The effect of stocking rate on herbage yield and quality and the influence of these factors and feed intake on liveweights of the sheep were recorded.The mean daily herbage organic matter available over the trial was 9.6, 5.8, 3.3 and 23% of the total liveweight of the sheep at each of the four stocking rates. The highest grazing pressure led to the production of high‐quality herbage, but also led to reduced productivity, low feed intake and liveweight losses. The most lenient grazing pressure failed to provide adequate herbage utilization. Even at the most intensive stocking pressure, only 66% of the herbage available to ground level was utilized in grazings after July.Intake results suggested that sheep of 45 kg liveweight required 1000–1200 g digestible organic matter per day to maintain body weight. Despite the higherin vitrodigestibility of herbage on offer at the higher stocking rates, intake was limited through lack of herbage; a high degree of correlation existed between herbage availability and herbage intake over the four stocking rates and at all grazings.It is concluded that the portable corral technique is well suited for grazing studies and the assessment of sward response to varying stocking rates and is particularly useful where facilities for more extensive studies are li

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1972.tb00702.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACTThe agronomic value of Syn 1 tall fescue, a synthetic variety derived from North African parent material, was determined in three experiments. Herbage yield, sward purity and digestibility were measured under cutting treatments for incremental sward growth during autumn/winter, and for sward regrowths during autumn/winter, spring and a complete season. Similar data were obtained for sward regrowths during autumn/winter and spring under defoliation by grazing. Syn 1 was compared with several of the north‐temperate region tall fescues, e.g. S170, Rozelle and Manade, also with S143 cocksfootSyn 1 showed yield superiority in autumn/early winter when there were comparable populations of tall fescue. Under cutting management, Syn 1 swards thinned out rapidly because of lack of winter‐hardiness and yields were depressed in the second season; the effects were worst under the winter foggage‐type management. Under grazing, with probably less severe defoliation, Syn 1 swards maintained yields for an additional season, but thereafter failed to persist Syn 1 swards had low spring‐ and annual‐yields.The yield advantage of Syn 1 in autumn/early winter was not sufficient to be of great agricultural value and with its shortcomings in winter‐hardiness and annual yield, it was considered unsuitable for West of Scotiand conditions. The main value of plant material such as Syn 1 may lie in ccmferring autumn/winter growth potential to winter‐hardy north‐temperate tall fescues in a bre

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1972.tb00703.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACTThe seasonal pattern of DM prodaction ofLolium perenne, Cynosurus cristatus. Anthoxanthum odoratum. Festuca ovinaandAgrostis stolonifera. cnt to 3 cm at 6‐week intervals was studied on five sites, ranging from 49 to 303 m above sea level, in north‐west Lancashire. Total annual production declined from a mean of 704 g/m2on the lowest site, to 553 g/m2on the highest, largely as a result of a severe depression in the spring peak of production, i.e. from 6.7 to 2.5 g/m2per day. Later in the year, the daily rate of DM production was similar on all sites. Species varied in their response to increased altitude;Loliumwas worst affected by this andFestucaleast. The significance of these results, and possible reasons for the decline in spring production are discus

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1972.tb00704.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACTGroups of 8 steers weighing 300–400 kg (660–880 Ib) were rotationally grazed on a ryegrass‐dominant pasture for 115 days. The systems compared were zero grazing (Z), field grazing conducted at the same stocking rate (FC), and field grazing conducted at a stocking rate varied with the intention of giving the same liveweight gain per uiimal as zero grazing (FV). Mean daily liveweight gains were: Z, 0.98; FC, 0.78; FV, 0.90 kg/animal (2.2, 1.7 and 20 Ib/animal), and liveweight gains/unit area were in the ratio 100:78:85. Organic‐matter intake, measured on four occasions, was, on average, Z, 6.54; FC, 6.18; FV, 687 kg/head daily (14.4, 13.6 and 15.1Ib).From these results it appears that a comparison of zero grazing and field grazing made at the same stocking rate is likely to underestimate the potential of field grazing for beef production fro

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1972.tb00705.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACTThree cutting heights, 1, 3 and 5 in. (2.5, 7.6 and 12.7 cm), and three cutting frequencies, 3, 6 and 10 weeks, were imposed on a pure sward of Italian ryegrass (Lolium multiflorum) cv. Irish. Lowering the cutting height increased the yield of DM, digestible DM, crude protein and crude fibre. Increasing the interval between cuts increased the yield of DM, digestible DM and crude fibre. The results are discussed in relation to other research findings and to the management of short‐term leys of Italian ryegras

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1972.tb00706.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACTAn experiment was conducted in two successire years to measure the effect of two levels of fertilizer N, 50 and 300 kg/ha (45 and 270 Ib/ac) on the productivity of pastures grazed by young beef cattle. Two stocking rates were imposed at the lower N level and 4 at the higher level. The responses per kg fertilizer N were approximately 1 kg liveweight gain, 20–24 Meal ME and 8–9 kg DM. Maximal yields of about 1000 kg gain/ha (890 Ib/ac) and 19,000 Meal ME/ha (7700 Mcal ME/acre) were recorded.Animal performance was similar on the low and the high N pastures. There was evidence that the chemical quality of pasture was lower on the low N pasture in the first year, but there was no difference in the second year.The numbers of dung pats per ha and the refusal of herbage due to fouling were reduced by Increasing the stocking r

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1972.tb00707.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.tb00708.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.tb00709.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY