ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1978.tb00801.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractStorage losses in moist hay treated with propionic acid were compared with those occurring in untreated moist hay in two experiments and with field‐cured hay in three experiments. Dry matter losses in treated hays ranged from 41 to 8.6% and from 1.7 to 12.6% in untreated hays. Digestible organic matter losses in both treated and untreated hays were generally greater than dry matter losses. Only in one experiment did propionic acid application significantly reduce nutrient losses in moist hays.Nutrient losses, and water‐soluble carbohydrate losses in particular, were shown to be correlated with maximum and cumulative bale temperatures during storage in two of the experiments. The rise in hale temperatures during storage was reduced in all three experiments, to a greater or lesser extent, by application of the additive.Loss of propionic acid from the hay during and after application was very large. In the three experiments 86.2, 85.3 and 85.6% of the acid applied was lost by the end of the storage period. Acid distribution studies indicated that variation in acid concentration within bales was as great as between bales. It was concluded that more research is needed into applicator design and position on the baler and into alternative application methods if the benefits of propionic acid as a moist hay preservative are to be fully exploi

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1978.tb00802.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractTwo contrasting Gremie perennial ryegrass and Blanca white clover seeds mixtures were established. Each sward type was either continuously or rotationally (four paddocks) grazed at two stocking rates by lambs of 26–28 kg initial mean live weight in two 12‐week experiments. Dry matter production, assessed by the cage method, was lower on the high‐clover sward during the first experiment but overall was similar between seeds mixtures. Clover content, and differences between sward types, declined with time and was lowered by continuous grazing in both experiments and by the higher stocking rate in the first experiment.Animal performance was related to intake and both were increased by lowering stocking rate, increasing clover content and adopting a continuous grazing system. The results are discussed in relation to the experimental methods used and to other published fin

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1978.tb00803.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractThe resistance often early, ten medium late and ten late flowering ryegrass populations to two rates of dalapon (2.8 and 5.6 kg ha‐1acid equivalent) was measured in a box experiment. There was no difference in the mean effect of dalapon on the maturity groups at the time of greatest yield reduction, but the recovery of the late flowering population was, on average, better than that of the medium late group. There was a range of reaction to herbicide within all three maturity groups and, in general, the high yielding populations without dalapon were the most resistant, but there were exceptions. Assessment at 2.8 kg ha‐1acid equivalent gave a similar ranking order to that using twice the amount of dalapon. The results of the current box experiment with seedlings were consistent with those obtained in the field at another location (Faulkner, 1974) for the eleven cultivars common to both trials. The resistance of a permanent pasture population was much lower than that of some cuttiv

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1978.tb00804.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractFour Italian ryegrass varieties of different origins and winter hardiness were grown as spaced plants at a lowland and an upland site and subjected to ten managements comprising two nitrogen levels and five autumn cutting treatments. Tiller mortality after the winter of 1971–72 was measured in March and subsequent spring recovery from winter damage in April.Although the winter was not severe, there was considerable winter kill, particularly at the upland site where the most severe treatment combinations killed up to 90% of the plants of the more susceptible varieties. In general, winter kill was increased by raising the level of nitrogen fertilizer and by late or frequent autumn defoliations, and significant interactions between locations and the two treatment factors emphasized the importance of the siting of the experiment.The varieties difFered in their overall winter hardiness, with Bb 1430 and RvP suffering less tiller mortality than S22 and Grasslands Paroa in all the treatment combinations, but significant interactions of varieties with locations and cutting treatments revealed that the magnitude of the difference between varieties varied with location and cutting management. Regression analysis of these interactions, however, showed that the tiller mortality of all four varieties increased linearly with the increasing stresses applied by the location × management combinations. There was no differential variety recovery from winter kill, the spring yields being entirely related to the level of tiller mortality experienced.These results are discussed in relation to the breeding of winter hardy varieties, the choice of variety and autumn management practi

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1978.tb00805.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractTwo experiments were conducted with sheep to investigate the effect of silage chop length on voluntary intake and eating and ruminating behaviour. The silages, made from Italian rye‐grass, either received no additive or formic acid at a rate of 4 g kg−1and were chopped to lengths of 5.3 cm (long), 1.8 cm (short) before ensiling or 1.8 cm (long/short) before feeding. The addition of the additive and short chopping improved the fermentation characteristics of the silage. Voluntary intake of silage dry matter and organic matter was higher with the short than with the long silage. Differences in silage digestibilities and cellulolytic activity did not explain the increase in silage intake. Sheep on the long silage had a lower rate of intake and a shorter ruminating time than on short silage, and thus the effective breakdown of the silage in the rumen was delayed, i.e. an increased latency time. Pseudo‐rumination was significantly higher on the long than on the short s

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1978.tb00806.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractThe effect of nutrient concentration on the reproductive development and seed yield ofPoa annuawas examined in a sand culture experiment. The nutrient concentration during the initial vegetative stage did not affect the time taken for double ridge formation by the main shoot but did influence the subsequent development of the inflorescence as did the post‐initiation level of nutrients. At low nutrient levels flowering was inhibited in some individuals but at the higher concentrations inflorescence emergence was hastened, inflorescence size was increased and, in particular, the number of spikelets and hence the number of seeds per inflorescence was greatly increased. The mean weight of 100 seeds was unaffected by the nutrient concentration. The number of reproductive tillers per plant was increased by high nutrient supply but the proportion of dry weight allocated to root development was reduce

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1978.tb00807.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractIn two experiments conducted with Ayrshire dairy cows in 1974 and 1975 on swards of S23 perennial ryegrass, four systems of continuous grazing were investigated. The leys received 345 and 370 kg ha‐1fertilizer nitrogen in 1974 and 1975 respectively and were stocked at the rate of five cows per ha. In 1974, a comparison was made between two systems which either integrated silage making with, or separated it from, the continuous grazing. The provision of a silage aftermath in late July increased milk yield after that time, but had no significant effect on milk yield over the 19‐week experimental period. In 1975, a comparison between weekly and monthly applications of fertilizer N showed no significant differences between milk yields in a 20‐week period. The feeding of supplementary concentrates from late July onwards significantly increased milk yield. The treatments in both years had only small and mainly non‐significant effects on milk composition. On average, excluding the concentrate treatment, the annual output of milk was 10,800 kg ha‐1using spring‐

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1978.tb00808.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractMineral acids, organic acids, salts and sterilizing agents were tested against a range of microorganisms at pH 4, 5 and 6. The antimicrobial spectra obtained revealed that hydrochloric, orthophosphoric, sulphuric and glycollic acids have no specific antimicrobial properties and merely function as acidifying agents. Acrylic acid, sulphamic acid and sodium formaldehyde bisulphite would apparently encourage a lactic acid‐type fermentation by suppressing the growth of butyric acid‐producing microorganisms. Chlorine dioxide and sodium metabisulphite are both antibacterial and of potential value for restricting silage fermentation Ammonium isobutyrate might find application in the production of a conventional fermented silage which is stable on exposure to air; it would appear particularly suited to silage made from wilted material. Sodium chloride apparently had no potential as a silage addit

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1978.tb00809.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractThe inhibitory effect of the herbicide dalapon on germination and shoot elongation was evaluated in two perennial ryegrass cultivars, Melino RvP and Cropper. These cultivars had been shown to be dalapon resistant and susceptible, respectively, in a previous comparison of 14‐week‐old plants.Dalapon (10‐2and 10‐3m) significantly reduced rates of germination and shoot elongation to the same extent in both cultivars.It is suggested that the effects of dalapon on germination and shoot elongation during the first 9 days of development are not indicative of levels of resistance in more mature

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1978.tb00810.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY