摘要:

Experiments with cows and sheep are described in which the voluntary intakes of hay and silage of differing digestibility were determined. The voluntary intake of hay increased consistently with increasing digestibility, but the relationship was not as well defined for silage. The addition of concentrates depressed the intake of hay, and this effect was more marked for hay with a high digestibility than with poorer quality hay. Concentrates appeared to depress the intake of hay by sheep more than by cows, an effect which was again more marked when the hay had a high digestibility value.

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1967.tb00509.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

In a recent paper by Anslow it was concluded that there was no significant relationship between Leaf‐area Index, light interception and growth rate in a perennial ryegrass sward. The author further concluded that higher growth rates would not be obtained by attention to this relationship. The data presented by Anslow are re‐examined in this paper and the results of the analysis showed that: (a) recovery growth of the swards followed a sigmoid pattern of growth, (b) at low values of LAI growth rate was low and maximum growth rate was attained when most of the visible light was intercepted by leaves, and (c) the relationship between yield and LAI was linear, indicating that leaf‐area increase after defoliation also followed a sigmoid pattern. These results are discussed in relation to Anslow's interpret

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1967.tb00510.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1967.tb00511.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

Stage of growth, leafiness and the accumulation of dead material were evaluated as factors causing differences in digestibility between varieties of perennial ryegrass, cocksfoot and timothy. In first growth these factors only partly accounted for the variation in digestibility between species but almost entirely accounted for the variation between varieties within each species. In the regrowths, heading behavior and leafiness were not closely associated with digestibility, which indicated that the variation between grasses following first growth may be a result of inherent differences.

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1967.tb00512.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

Estimates were made of the intake and production of 3 flocks of dry Merino ewes stocked at 4, 8 and 12 sheep/ac which received no anthelmintic treatment. Similar estimates were made on ewes stocked at 4.5, 7, 9, 11 and 13 sharp/ac and maintained virtually free of worms by fortnightly drenching with thiabendazole. Parasite infection depressed wool production and appeared to increase intake. As a result, gross efficiency of wool production was depressed from 14.1 to 10.8 g of wool per kg of organic matter ingested.

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1967.tb00513.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

Data from two field experiments, and from a root observation trench, suggest an annual cycle of root growth by grass swards. The production of adventitious roots from the tillers of four grass species, and from perennial ryegrass in a grass/clover sward varied greatly during the year. They were produced in increasing numbers through late winter to early spring; this rate fell sharply in April or May, and was low in summer. The differences in this annual cycle between grass species were small. Examination of roots of perennial ryegrass in a glass‐sided trench showed that root elongation was most rapid in summer and was largely confined to the lower soil horizons. Rather more roots were produced in early autumn than during summer, but the rate of elongation was slow from October until spring.Individual roots of grasses appeared to survive for limited periods. Their longevity depended upon the time of year in which they were first formed; those produced in autumn or winter lived longer than those produced in spring or summe

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1967.tb00514.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

An account is given of a method for measuring short‐grazed pastures. The procedure has particular value in studying the relationship of animal performance to pasture availability. A number of other pasture characteristics may be measured concurrently. These include species composition, tiller number and mean weight, stem‐base material, roots, rhizomes and plant litter. The influence of core size and shape is studied and variance components repor

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1967.tb00515.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

A conservation experiment is described in which the losses in ensiling heavily–wilted, baled herbage of 49–58% dry–matter content in a completely sealed polythene film is described. In addition, a comparison is made between silages with and without sodium metabisulphite added as a preservative. The mean DM loss for the control silages was 11.1%, and that for the metabisulphite–treated silages 12.8 %. These losses, and the individual crude–nutrient and digestible–nutrient losses are compared with those obtained for heavily–wilted and conventional silage made in lined trench silos. Metabolizable energy values for the grass and silages are a

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1967.tb00516.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

The herbage and associated habitat factors of 15‐ to 20‐years‐old reclaimed hill pastures were investigated in Mid–Wales. These swards had been reclaimed from natural hill vegetations by ploughing and sowing. The results were examined to determine which habitat factors were associated with sward reversion. Particular emphasis was given to determining how far reversion was under the control of the farmer. On ill‐drained soils the swards became heavily infested withJuncus effusus, regardless of management. On well‐drained soils reversion was largely prevented by maintaining an adequate stocking rate in summer, coupled with periodic applications of lime and basic slag. Inherent podsols required approximately twice as much lime as inherent brown earths for the equivalent maintenance of soil pH and sward

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1967.tb00517.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

The root growth of 3 temperate–region grasses (perennial ryegrass, Italian ryegrass, and cocksfoot) and of 3 tropical grasses (Dallis grass, Bahia grass, and Rhodes grass) was investigated in large glass–sided root–boxes. The trend of root numbers and the rate of elongation of roots were ascertained to discover how the Japanese climate affected the root growth of these species.All the temperate–region grasses produced new roots vigorously during spring, but root growth ceased in August, whereas the roots of tropical grasses grew rapidly in this month. The alternate use of these two types of grasses during the growing season may therefore be worthwhile

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1967.tb00518.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY