Sources of genetic influence in the Queensland Merino industry.

Abstract

Animal Production in Australia Vol. 15 SOURCES OF GENETIC INFLUENCE IN THE QUEENSLAND MERINO INDUSTRY MARY ROSE* SUMMARY An analysis of records for Queensland studs in the Australian Stud Merino Flock Registers for the period 1960-80 showed that there were very few Queensland studs. The annual number ranged from 58 to 77 and in 1980 only 66 of the 1,551 Australian studs were in Queensland. The mean duration of all studs in 1980 was 37.5 years (range 1 - 125) and of discontinued studs 19.6 years (range 1 - 90). There was no relationship between flock size and the proportion of studs which discontinued. It required sold more ram sales existence was estimated that Queensland stud by Queensland commercial flocks. than 5,000 rams each over the 21 in this time. Eighteen of these in 1980. ram sales provided 54% of the rams Twenty-four Queensland studs (18%) years and accounted for 74% of all influential studs were still in Interstate studs did not have a major influence through sales of rams to Queensland studs, but they supplied an estimated 46% of rams used by commercial flocks. INTRODUCTION A study of the consequences of breeding strategies in the Queensland Merino sheep industry must consider the structure of the industry, the sources of genetic material and their relative importance. Short and Carter (1955) first analysed the structure of the Australian Merino industry and showed that there were no parent studs in Queensland and only one South Australian strong wool and two medium Peppin daughter studs. A later study by Roberts et al. (1975) identified 15 Queensland daughter studs (1 fine; 1 non-Peppin; 12 Peppin and 1 S.A. strong wool). Moule (1952) in a comprehensive analysis of the statistics of the Queensland sheep industry showed that the Queensland Merino studs supplied approximately 57 % of the rams required by commercial flocks. This study was made to examine the importance of the Queensland Merino studs as suppliers of rams to Queensland commercial flocks and to identify other sources of genetic influence in the Merino industry. MATERIALS AND METHODS The number of Queensland registered Merino studs, their duration, their annual ram sales, the number of rams they purchased and their source were recorded for the period 1960-80 using the Australian Stud Merino Flock Registers Volumes 38 to 58 (1961-81). * Department of Animal Production, University of Queensland, St. Lucia, Qld . On leave from: Wool Biology Laboratory, Department of Primary Industries, 4105. Yeerongpilly, Qld 561 4067. Animal Production in Australia Vol. I.5 RESULTS AND DISCUSSION Number of studs Australia had a total of 1717 registered stud Merino flocks in 1960 and 1551 in 1980. Very few of them were in Queensland. In 1960 there were 69 studs and in 1980, 66 (the number ranged between 58 and 77 during the period 1960-80). There was a total of 132 studs registered during this period. By comparison South Australia had 309 in 1960 and 306 in 1980 (range 296 - 358) while New South Wales studs declined from 705 in 1960 to 432 in 1980 (range 432 - 730). In the 24 million in resulted in a declined from same 1964 loss 9.5 period Queensland sheep numbers declined dramatically from over to 10.6 million in 1980. Both the 1965 and the 1968 droughts of more than 20% of the sheep population. Breeding ewe numbers million in 1960 to approximately 5 million in 1980. Duration of studs The mean duration of all studs still in existence in 1980 was 37.5 years (range 1 - 125) while those which discontinued in the 21 year period averaged 19.6 (range 1 - 90). There are some very old studs in Queensland; the oldest 10 in 1980 averaged 93.7 years. Table 1 presents the proportion of studs of various flock sizes, their mean duration and the number which discontinued during the period 1960-80. The Queensland stud industry differed from the Australian industry in general (Connors and Reid 1976) in that small studs were no less unstable than larger ones. This anomaly may be due to the relatively small number of Queensland studs in each class but probably only emphasises that there is a great variety of reasons why studs discontinue and many do not depend on stud size or ability to sell rams. TABLE 1 The proportion of studs of various flock sizes, their mean duration and the number which discontinued during 1960-80 Influential Queensland studs Mean annual number of sales per Queensland 198 (range O-1696). Over the 21 years 12 studs Eighteen per cent of studs which operated between for 74% of all rams sold and of these 24 studs 18 1980. stud each 1960 were in the 1960-80 period was sold more than 10000 rams. and 1980 were responsible still in existence in Since individual animals are not registered in the Merino stud industry, it was not possible to identify the most influential animals as has been done in other livestock industries (e.g. Herron and Pattie 1977). Instead it was assumed 562 Animal Production in Australia Vol. 15 that the studs which sold the greatest number of potential sires were the most influenti al. Studs which sold more than 5000 rams (1.2% of the total rams sold) were defined as influential and in this period there were 24 such studs. Of particular interest were the top 12 studs which sold 54% of the rams. There were 10 of these still in existence in 1980. Not included amongst the influential studs were the studs which had large annual sales but discontinued and two studs, registered in the last five years of the study period which are becoming important because of large annual ram sales. Sources of genetic influence Of the 15 Queensland daughter studs identified by Roberts et al (1975), nine were still operating in 1980 and only seven of these were influential studs in the Queensland industry. In the period 1960-80, 3361 rams were purchased by Queensland studs from interstate; the majority (3282) coming from New South Wales. Parent studs supplied 48% of interstate rams and of these 84% were medium Peppin, 13% fine, 1.6% medium non-Peppin and 1.5 % South Australian strong wool. To ascertain the influence of these interstate rams a study of their relative importance within the influential studs was made. For each of the 24 studs the number of interstate rams purchased was expressed as a percentage of the sires used. As the number of sires in use was not recorded prior to 1965 the study covered the period 1965-80. For 16 of the studs the proportion of interstate rams was less than 1% and in only four of the studs did it exceed 10%; the highest being 32%. These four studs each bought rams from two different studs and each sold 2% or less of all rams sold in Queensland. Even if some allowance were made for preferential usage of purchased rams the influence of these interstate rams would not have been great. Although their influence through sales of rams to Queensland studs was not great, they had an important effect on the industry through sales directly to commercial flocks. The number of rams required each year (1960-80) by commercial flocks was estimated by subtracting the number of stud ewes mated from the total number of breeding ewes in Queensland and allowing a 2 % ram joining rate and an average of four joinings per ram. By this formula Queensland stud ram sales accounted for 54% of the estimated rams required by commercial flocks. This is similar to the estimate of 57% published by Moule (1952) for the period 1937-49. Most of the remaining rams required were supplied by interstate studs from New South Wales and South Australia. CONCLUSIONS Queensland has comparatively few studs and the number has changed little in the last 30 years. Each year a small number of new studs registered and some discontinued so there have been continual changes to the list of studs operating. However compared with other sheep breeds (e.g. Fogarty 1978), the mean duration of Queensland Merino studs was long; the oldest being over 100 years. No relationship was observed between flock size and the proportion of studs which discontinued so it was likely that biological or economic factors associated with small flock size were not important causes of studs discontinuing. The sources of genetic influence during this period have been a well-defined 563 Animal Production in Australia Vol. I5 and small group of Queensland and interstate studs. A few influential Queensland studs played a very important role in supplying Queensland's annual ram requirements and since most of these did not purchase interstate rams on a large scale or on a regular basis, their own breeding policy would have determined to a large extent the flow of genetic improvement to their clients. The other major influence on the Queensland industry was that of interstate studs, especially those with an established clientele. Among these were many of the large parent studs. ACKNOWLEDGEMENTS It is a pleasure to acknowledge the assistance of the Queensland Merino Stud Sheepbreeders' Association who provided missing volumes of the Stud Register. The author is supported by an Australian Wool Corporation Postgraduate Scholarship. REFERENCES CONNORS, R.W. and REID, R.N.D. (1976). FOGARTY, N.M. (1978). Proc. Aust. Soc. Anim. Prod. == 11:9. Aust. J. Exp. Agric. Anim. Hush. == 18:165. Aust. J. Agric. Res. z&1119. HERRON, N.D. and PATTIE, W.A. (1977). MOULE, G.R. (1952). Department of Agriculture and Stock, Division of Animal Industry Pamphlet No. 15. ROBERTS, E-M., JACKSON, N. and PHILLIPS, JANICE M. (1975). 22:6. Breed. == SHORT, B.F. and CARTER, H.B. Wool Technol. Sheep (1955). CSIRO (Australia) Bull. No. 276. 564