ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1973.tb00712.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

ABSTRACTTwo grazing systems, a paddock system and a ‘Wye College’ system, were compared in two 20‐week experiments nsing 16 and 20 spring‐calved Ayrshire cows in 1970 and 1971, respectively. A sward of S23 perennial ryegrass was used, and an average of 342 kg N/ha (305 lb N/ ac) was applied per annum. The paddock system had 28 separate paddocks; one paddock was grazed each day in rotation and occasionally topped in mid‐season. The Wye College system had 4 plots of equal size and the cows were offered 1/7 of one plot each day; no back fence was used and surplus herbage was neither cut nor topped. The stocking rate on hoth systems was 1 cow per 0.20 ha (0.49 ac) in 1970 and per 0.16 ha (0.40 ac) in 1971. The mean daily milk yields per cow on the paddock and the Wye College systems were 16.2 and 15.3 kg (35.7 and 33.7 lb), respectively, in 1970; and 18.1 and 18.4 kg (39.9 and 40.6 lb) in 1971. The average annual output of milk was 13,500 and 13,150 kg/ha (1200 and 1170 gal/ac) on the paddock and Wye College systems, respectively. The fat and solids‐not‐fat (S.N.F.) contents of the milk were not significantly affected by the grazing system. It is concluded that the Wye College system was as effective as the paddock system in producing a high output of mUk per ha, but at a lower cost and with far fewer managem

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1973.tb00713.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

ABSTRACTTwo experiments are reported in which 119 steers were fedad lib. on maize silage, supplemented with different proportions of dried lucerne. In addition, the effect of including white fishmeal with the silage at levels up to 13% of the total diet was studied in one experiment. In another, the effect of adding urea to the silage (at 0.9% of the DM) was investigated.In hoth experiments the response in liveweight gain to increasing amounts of lucerne was curvilinear. The highest mean level of daily gain (1.5 kg/head per day) in the first experiment was achieved when the diet contained 62% lucerne or 13% fishmeal. In the second experiment the highest mean daily gain (1.1 kg/head per day) was achieved when the diet contained 71% lucerne.Daily liveweight gains were simOar for the cattle fed 25% of the diet as lucerne with sQage to which urea had heen added, and for those fed higher proportions of lucerne with untreated silage.

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1973.tb00714.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

ABSTRACTThe need to isolate defoliation from other influences arising from grazing cattle nsed in experiments has led to the development of a cage which allows cattle to graze, hut protects the sward from treading and the deposition of faeces and nrine. The technique is descrihed and a description given of experimental work on the harvesting of swards in the presence or absence of these other influences.

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1973.tb00715.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

ABSTRACTA single unit grass‐meter has been developed to replace the twin transmitter‐receiver units which have been in use since 1958.In the new design a radio‐frequency capacitance bridge is mounted on top of a measuring head. Introduction of grass into the measuring head unbalances the bridge and the amount of unhalance, which is a function of the mass of the herbage, is indicated on a micro‐ammeter. Two ranges are incorporated so that sheep pastures with short grass and cow pastures with long grass can be m

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1973.tb00716.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

ABSTRACTThe seasonal pattern of digestible organic matter (DOM) and crude‐protein production ofLolium perenne, Cynosurus cristatus, Anthoxanthum odoratum, Festuca ovinaandAgrostis stoloniferacut to 3 cm at 6‐week intervals was studied at five sites ranging from 49 to 303 m above sea level in north‐west Lancashire for the years 1969–70.DOM production declined from 482 g/m2on the lowest site to 220 g/m2on the highest; similarly protein production declined from 142 g/m2to 73 g/m2. Small but significant differences in the percentage of crude protein occurred only ia 1970, whereas DOM as a percentage of DM in the various species differed considerably between sites in both years. The significance of the results and the seasonal fluctuations in production are di

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1973.tb00717.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

ABSTRACTSeeds ofMedicago sativa, Trifolium subterraneum, Lolium perenneandPhalaris tuberosawere sown on different soil surfaces and the effects of strength, tilth and heterogeneity of the surface on the entry of the radicle into the soil were noted.On a level, finely structured soil surface prepared in the laboratory slight increases in soil strength markedly reduced percentage radicle‐entry. At constant soil strength, radicle‐entry was greater on coarse than on fine tilth; which helped to explain the higher percentage radicle‐entry on heterogeneous soil surfaces taken from the field compared with the level, finely structured surface, prepared in the laboratory despite the lower soil strength of the latter.As conditions for radicle‐entry hecame less favourable (stronger, smoother surface) the rate of radicle‐entry became slower and there was a greater use of radicle‐entry methods in which the radicle was more exposed to desiccation.The radicle‐entry ability of the four species declined in the order: perennial ryegrass

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1973.tb00718.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1973.tb00719.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Book reviewed in this articles:SPEDDING, C. R. W.Grassland ecologyCRAVEN, F.; GUNARY, D.The importance of grass in profitable beef productionROBERTS, E. H.(Editor) Viability of seedsBLAND, B. F.Crop production: cereals and legumesCHIARAPPA, L.(Editor) Crop loss assessment methodsHORSFALL, J. G.; BAKER, K. F.; ZENTMYER, G. A.(Editors) Annual review of phytopathologyPAIR, C. H.; HINZ, W. W.; REID, C.; FROST, K. R.(Editors) Sprinkler irrigation

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1973.tb00720.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1973.tb00721.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY