摘要:

A series of experiments in eastern Scotland, carried out over a 7–year period, on the application of N fertilizers to Italian ryegrass for producing early spring grass, indicated that maximum yields are likely to be produced if the fertilizer is applied not later than the middle of March in most seasons. Only rarely did application in February result in a loss of N and in reduced herbage yields. Italian ryegrass appears to be able to make some growth at temperatures below 40†F.Increasing the rate of N application resulted in increased DM yield, the response averaging 9–4 lb DM per lb N. Herbage N concentration was increased by the additional N fertilizer. Nitro–chalk and ammonium sulphate were equally effective in producing early grass, irrespective of applicati

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1968.tb00554.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

Six calves, six heifers and six dry cows grazed a mature sward (treatments A and B) and a leafy aftermath (treatment C) in succession. The yields of herbage on the two swards were 7100 lb and 1950 lb DM per acre (7950 kg and 2180 kg per ha), respectively. The amounts of herbage offered daily were 47 lb (21–5 kg) DM per head (treatment A), 70 lb (32 kg) (treatment B), and 60 lb (27 kg) (treatment C), Two estimates of herbage organic–matter intake (O,M,I,) were made on each treatment; records of grazing behaviour were made on treatments B and C, The digestibility of the diet selected on treatment C was higher than that selected on treatments A and B, and the animals ate significantly more O,M, on treatment C, The total grazing times on treatments B and C were similar, but the animals found it more difficult to graze on treatment BHerbage O.M.I. increased significantly from treatment A to treatment B, even though the quantity of herbage offered per day on treatment A greatly exceeded the amount eaten. The increase in O,M,I, was found to be associated with an increase in faecal 0,M, output, but the digestibility of the diet did not cha

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1968.tb00555.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

The treatments in this summer–grazing experiment were designed as a 2 × 3 factorial, there being two levels of nitrogenous fertilizer (nitro–chalk), supplying 0 and 336kg of N/ha per annum (NO and N3, respectively) and three stocking rates. The fertilizer was applied in 7 dressings at approximately three–weekly intervals. The animals used were Hereford x Friesian steers; these were slaughtered at the end of the grazing season. The stocking rates were calculated on the basis of expected herbage production. The experiment was laid out in 6 randomized blocks which were grazed in rotation. Two blocks were cut for conservation before grazing each year; up to the end of June only 4 blocks were used for grazing.There was little contamination of the swards with unsown species. With the NO swards the clover contents declined each year, but remained fairly high at over 20% in 1965. Clover contents also declined each year in the N3 swards and by 1965 were only 2 to 4%.The quantities of herbage cut for conservation were higher from the swards receiving N. The live–weight gains of the cattle (per head) were higher at the lower stocking rates, the effect of stocking rate being more noticeable in the July to Oct. period. Live–weight gains per ha increased at the higher stocking rates. In 1963 and 1965, as stocking rates increased carcass weights per animal decreased and carcass quality, as indicated by the commercial grades, was poorer. In 1964, a dry spell from July to Oct. necessitated the removal of cattle from the experiment and the effects of treatment on carcass weight and quality were no

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1968.tb00556.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

The date of the spring appearance of inflorescences in herbage plants has been studied at the Welsh Plant Breeding Station, Aberystwyth (Lat. 52”N.), and data collected between 1926–64 examined forLolium, DactytisandPhleum. The seasonal variation in mean date of emergence showed a range in perennial ryegrass of 14 to 29 days, in Italian ryegrass 14 to 20. in cocksfoot 18 to 25, and in timothy 14 to 19 days. Inflorescence initiation under field conditions is a response to increasing photoperiod, but the rate of development and the date of appearance is controlled by the weather, especially temperature. There is a negative correlation between accumulated temperature and head emergence. The mean emergence date provides a good index of the year by year heading sequence of the different cuuivars. A study of the air and soil temperatures between February and May showed that the accumulated temperature above 42°F for March, and the number of times that the soil temperature at 4 in. deep reached and exceeded 42Tprovide a means for predicting the degree of earliness or lateness of spring in relation to head emergence in grasses.Observations on the phenology of flowering plants and especially fruit trees can also be used for prediction. This second method is simpler and more direct and it has the further advantage of providing a slightly earlier fore

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1968.tb00557.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

During the winter months of 1963 and 1964, mature non–pregnant Clun Forest ewes at pasture were equipped with pedometers to study the value of these instruments for measuring distances walked, and to investigate the importance of weather on the distances travelled. Approximately 80 periods were recorded, each of about 24 hours. The accuracy of the measurements was checked by using a rangemeter and it was found that the reliabihty of pedometer records must be assessed on the animal from which they are obtained. The individual characteristics of the pedometers and/or the sheep gave rise to inaccurate records from about 50% of the instruments studied.Multiple regression analysis of data for each of the three sheep which provided suitable records revealed that, in dry weather, the average distance walked per hour of recording period increased signiJBcantly with mean air temperature in one case and with hours of bright sunshine in another. Wind–speed effects were unimportant. The distance walked by all three sheep increased significantly with hours of daylight per recording period, and this was the only variable found to affect distance walked in wet weather. Differences between average distances walked per hour under dry–and wet–conditions were non–significant.It is concluded that for measuring the distances walked by sheep, the disadvantages of the pedometer outweigh its a

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1968.tb00558.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1968.tb00560.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

Book reviewed in this article:BAKER, R. D., SPEDDING, A. W., KILKENNY, J. B. and TAYLER, J. C. An intensive system of beef production from grassland, using autumn‐born calves from the dairy herd.M.A.F.F.At the farmer's service, 1967‐8.M.A.F.F.Aspects of dairy economics, 1962‐1965.DAVIES, WILLIAM.[The grasslands of Spain.]DIVISION OF PLANT INDUSTRY, CSIRO.Australian herbage plant reg

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1968.tb00561.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY