Winton Grazing Trials

New Zealand Journal of Agriculture, Volume 66, Issue 2, 15 February 1943, Page 85

Winton Grazing Trials

Feeding Value of Perennial Ryegrass Strains

By

J. W. WOODCOCK,

Fields Superintendent,

Dunedin, and A. STUART, Instructor in

Agriculture, Invercargill.

WHEN certified perennial ryegrass was first introduced to Otago and Southland, farmers did not receive it with enthusiasm. This was probably because too much was made of its regional aspectit was called Hawkes Bay or Poverty* Bay ryegrass more often than it was called certified ryegrass, and farmers generally, with a -good deal of justification, have to be convinced that a variety or a strain from some other place is suitable, for their own conditions. Since the climatic conditions of Hawkes Bay or Poverty Bay were so different from their own, Southland farmers therefore were difficult to convince that this strain of ryegrass, considered by North Island standards to be more productive and more perennial than their own strain, was suitable for pastures, in Southland. T rials Trials and demonstrations , were laid down by officers-of the Fields Division, and these proved conclusively that the claims made on behalf of certified ryegrass were substantially correct. But the trials also proved that while the latter was a more or less standardised article, Southland ryegrass was not. There were some lines which were very poor and did not deserve the term “perennial”; there were other lines which lasted 4 or 5 years; but there were also some which lasted for much longer, and - even although they did eventually “go out,” they outlasted the span of life for a Southland pasture, which, on a rotational farm, is ploughed up every few years to make room for turnips or oats. Even in official quarters this aspect is being recognised and has resulted in a “new model” being produced for such conditions, namely, “short rotational ryegrass.” The present position is that in Southland the use of certified ryegrass is still not universal as it is in most other districts. Until it has been tried and tested to their satisfaction, many farmers are not inclined to dispense with the lines of ryegrass originating from their own district. They argue thus: “Performance under .our farming conditions over a period of six or seven years counts for more than a ‘peren- ; nial’ reputation. We have in the South seed from old pastures which, while

not possessing pedigree, breeding, or the capacity to satisfy a laboratory test, will fatten more lambs under Southland conditions than the strains of certified ryegrass from the : North Island.” . It is difficult to prove or disprove such a statement for it entails an elaborate . experiment extending over • a period of years, using livestock ’as the yard-stick rather than mere observation or the use of a lawn mower, or tiller counts, or the measurement of grazing days, or any of the other shortcuts of the grassland scientist. It was fortunate, therefore, that in the very district where this ryegrass controversy was the strongest there was available the Winton Experimental Farm on which an experiment could be conducted, and where sheep and lambs could be available for trial. It was therefore decided to test out on this farm the best, strains of Southland ryegrass against' the Hawkes Bay type to determine whether or not the former was a better proposition for the purpose of fat lamb production. -

The Winton Experimental Farm Committee set itself to carry out the trial in a very thorough manner, more land was leased on an adjoining area to supplement land already available, while the farm, hitherto devoted to dairying, was changed over to sheep. Details of Layout . Details of the sowing of the experiment were published in the ; “Journal of Agriculture,” January, 1938, and the first year’s results in the issue of September, 1938. To reiterate briefly, four comparable paddocks,., each 2 J acres, were sown in October, 1936, with a blend of ten lines of Hawkes Bay. rye-, grass (all purchased locally), while four other paddocks. were sown with a blend of the ten best Southland ryegrasses available. It should be noted that this trial is not strictly one comparing certified with , uncertified seed, but rather "one comparing'■ best ■■ Southland types irrespective of. certification with standard certified Hawkes Bay types on sale in Southland. The Southland seed was

obtained from areas at least 10 years old, and some of the lines used in the blend were up to the standard of certification in the class now known as “Permanent Pasture.” The seed mixture sown was at the rate of 30 lb. of ryegrass plus 3 lb. of ordinary commercial Southland white clover. . (In order, to avoid repetition . throughout the remainder of this report, the fields containing Hawkes Bay ryegrass will be' referred to as. “Northland” fields, while those sown with, Southland ryegrass will be known as “Southland” fields.) v All the fields were well limed and manured when sown down, and they received annual applications of phosphatic fertiliser. A line of 120 twotooth Romney ewes was divided up into two separate flocks, 60 being confined to the “Northland” fields, and 60 to the “Southland” fields. The results from only three of the four fields of each treatment are taken into account, however, because the fourth field was reserved as a holding paddock. In low production periods it was intended that any ewes taken out temporarily from the three main fields would be held on the type of herbage they were accustomed to. Both flocks grazed their own specific type of ryegrass from February, 1937, until the close of the experiment in March, 1941.

This report therefore not only describes the progress of fields sown with different ryegrass strains, but it also gives a history of two sheep flocks, from youth to old age, grazed on the two types of ryegrass. It records the weights of wool produced ■ and its value, the number of lambs, lambing percentages, the weight of fat lamb and its value during each of the four years. Conduct of Trial Salient features of the conduct of the trial were: — 1. Both treatments were grazed in conformity with accepted principles of good management. . At no stage was any pasture allowed to get out . of hand. or grazed too hard. Extra sheep were brought in to keep down any surplus growth, or some ewes . were moved to. the fourth paddock when growth on the three main paddocks appeared to be getting short. Thus, great care was taken to ensure that surplus growth or lack of feed were avoided. Either of these two circumstances would have had a direct bearing on the. thriftiness of the lambs. 2. Both ewe flocks were kept up to 60 in number; in the event of deaths other sheep of the same age were substituted, except in the last

year. Fortunately this was rarely necessary. Southdown rams ■ were used and were changed from one. flock to another at tupping so as to eliminate the influence of sire on the lambing returns. ■ ; ..... 3. During winter it was not possible to keep the flocks in their respective pasture all the time, and they had to be put on to swedes for five or six weeks. During this period they had a run-off on to a common pasture, but hay composed entirely of Timothy and clovers but no ryegrass was fed out to them. 4. The ewes grazed normally and did not have to be forced on to the feed available. At ,no time was there any suggestion of unpalatability. Occasionally the mower was used to keep down thistles and similar weeds. 5. At shearing,' wool from each flock was kept separate and this was valued through the courtesy of the Southland Farmers’ Co-op. Association, Invercargill. Weights of wool did not include belly wool except in the first year. 1 6. The lambs from each flock were branded at birth with separate distinguishing marks so that no confusion could arise in their identity. Lambs were drafted when considered necessary and a report on the weight,

- condition, and price obtained from the carcasses was furnished by the Ocean Beach Freezing Co,, Ltd. Lambs remaining at weaning time were valued at the current ruling rates for rape lambs. : Composition of Pastures . All the paddocks established well. A common flock was grazed on them during January, 1937, chiefly to eat down the spurrey which , came up with the grass. The fields were grazed, again by the common flock during February, March, and April, after which the sheep were divided up into their respective units. In the initial establishment the Northland fields appeared to have the better sward, especially as regards ryegrass. The establishment of white clover was poor in the early stages. .■ ■ : . ■ Point analyses were made by Mr. S. H. Saxby, Instructor in Agriculture. Dunedin, during the progress of the trial. These were carried out twice a year,., namely, spring and autumn, to determine the proportion in which the various species were present. To enable comparisons to be made from year to year these point analyses have been expressed as percentages in the accompanying table. . , It will be seen that, after October, . 1938 (two years after the trial was sown), the ryegrass content of the Southland fields began to decline until an equilibrium was reached at about 30 per cent, during the last two years. No marked difference in clover content is apparent although this species was slightly more prevalent on the Southland fields. The most marked differences in composition were those in connection with brown top and also in regard to inferior grasses and weeds. (To be continued)

Date. Fields. . Bare Ground . % Perennial Ryegrass . . % . White Clover Browntop % % . Inferior .Grasses oi BrowntopWeeds. % . % Inferior Grasses oi Weeds. % May, 1937 Northland 39.651.5 4.8 ■ 4.1 Southland 45.7 ■ 46.3 ■ 3.8 — 4.2 October, 1937 .. Northland 24.0 ... ,, 62.9 . 8.7 trace 4.4 Southland 24.0 . 61.3 8.5 . trace '' 6.2 June, 1938 . Northland 31.9 ’ 57.3 7.3 1.3“ 2.2 Southland 35.1 50.6 9.1 1.2 4.0 October, 1938. .. Northland . 26.0 59.8 .. , ,6.4 111 . 6.7 i Southland 22.3 • 50.8 ■ . ’ 9.2 4.7 13.0 13.0 May, 1939 Northland 20.4 60.0 13.0 . 1.6 . 5.0 Southland ,21.2 • 44.1 16.3 6.1 12.3 November, 1939 Northland ' 12.1 . 45.6 ■ 25.8 1.9 14.6 Southland ' ■ 10.0 " '. 31.7 ' ’ 26.6 11.5 20.2 April, 1940 . Northland 9.2 . - 60.8 ■ ' 22.5 3.8 3.7 Southland 10.6 35.5 24.1 17.9 11.9 October, 1940 .. Northland , 7.3 50.8,J25.0 '. 5.9 11.0 Southland ■ 7.7 .- 31.4 -■*: 24.9 15.6 20.4 May, 1941 Northland , .. 19.5 59.2 , 12.1 1.5 ■■7.7 Southland ■ 16.3 38.5 . 19.0 12.2 14.0

TABLE I.—Point Analyses of Trial Fields (Per cent.)