Survey of post-shearing losses.

Abstract

A SURVEY OF POST-SHEARING LOSSES By P ETER E. G EYTENBEEK * . Summarv A survey of seventeen properties in the Kybybolite area was carried out following severe weather conditions in September 1960. Total losses represented 8 03 per cent. of all sheep shorn in the previous fortnight. Of the sheep shorn 5 days or less 12.2 per cent. died, but of those shorn 8 to 12 days prior to the storm only 0.7 per cent. died. Losses were higher in Merino flocks than in crossbreds. Body condition of the sheep appeared important, although many fat sheep died. Sheep of all ages were affected. The position of available shelter appeared important, and the need to confine sheep near shelter was apparent. I. INTRODUCTION Severe weather conditions caused considerable losses in newly shorn sheep in the south-east of South Australia in September 1960. Over the period September 24-25 an estimated 5,000 sheep died as the result of exposure to low temperatures, strong to gale force south-westerly winds, and heavy rain. Weather conditions were exceptional for the area. Rainfall recordings for the 24 hours to 8 a.m. on September 25 were up to 3 inches, and total wind travel (at the Kybybolite Research Centre) exceeded 200 miles for only the third occasion in thirteen years. II. METHODS A survey of 17 properties in the Naracoorte-Kybybolite area was undertaken to determine the extent of losses, contributing factors, and the effectiveness of action taken by flock owners. A full report of the survey will appear elsewhere (Geytenbeek 1961). III. RESULTS A summary of losses on the 17 properties surveyed is set out in Table 1. Losses on individual properties ranged from 2 to 550. The total mortality of 2,055 sheep represented an overall loss of 8.3 per cent. of all sheep shorn during the fortnight preceding the storm. IV. DISCUSSION A feature of the losses is the death of 12-2 per cent. of the sheep shorn 1 to 5 days prior to the storm compared with only 0.7 per cent. of sheep shorn. 8 to 12 days prior to the storm. Deaths in sheep 1, 2, 3, 4, and 5 days off shears were 394, 437, 464, 302, and 410 respectively. These figures indicate that substantial losses can occur in sheep more than 2 days off shears. This was in direct conflict with owner opinion which held that only sheep up to 2 days off shears would succumb. The shedding * Department of Agriculture, Kybybolite Research Centre, South Australia. 185 T ABLE 1 SUMMARY OF SHEEP LOSSES Merinos Number of properties Total sheep shorn (12-16 September incl.) (19-23 September incl.) 10 2,375 11,069 Number Percentage of of those Sheep Shorn Deaths in sheep 1 to 5 days off shears t Deaths of sheep 8 to 12 days off shears 1,539 20 13.9 O-8 Corriedales and Crossbreds 8 1,733 5,925 All Breeds 4,108 16,994 No. 489 7 - % No. % 8.2 oa4 2,028 27 12.2 O-7 * One property ran both Merino and Crossbred flocks. -1 No sheep were shorn on 17 and 18 September, therefore none were 6 or 7 . days off shears at the time of the storm. of some 1,800 freshly shorn animals, and the moving of others to paddock shelter undoubtedly reduced losses in the sheep 1 to 2 days off shears. Losses in Merino flocks ( 11.6 per cent.) were higher than in crossbred flocks (6.5 per cent.). This was attributed to the high percentage of wethers and weaners on the Merino properties surveyed. The wethers generally were in lower body condition (due to being carried at heavier stocking rates) than ewes that were rearing lambs. Likewise Merino weaners were generally in store condition onlv. Sheep of all ages from weaners to 5% years old died. In general, losses were heaviest in sheep low in condition, though many fat sheep died also. In no case could losses be associated with a prolonged period of starvation prior to or following shearing. The prevailing winds were from the west and south-west. Sheep found dead were invariably against fences on the eastern sides of the paddocks. This was so despite, in some cases, the existence of excellent shelter on western fences. Sheep had obviously travelled with the wind. On three properties individual flocks found shelter in the north-east corner of the paddock, and losses were negligible. Owners who moved sheep throughout the night reported that, unless confined, the sheep left shelter and drifted in a north-easterly direction into open country. It is considered that critical re-assessment of the positioning of shelter belts (both natural and planted) is necessary if these are to prevent post-shearing losses under adverse weather conditions. G V. REFERENCE .-A survey of post-shearing losses due to adverse weather condiEYTENBEE K , P. E. (1961) tions. Department of Agriculture S.A. Exptl. Record (in press). 186