Overfat Ewe Mutton is a Serious Problem

New Zealand Journal of Agriculture, Volume 88, Issue 2, 15 February 1954, Page 98

Overfat Ewe Mutton is a Serious Problem

By

S. H. SMITH-PILLING,

Supervising Meat Grader, New Zealand Meat Producers Board,

and R. A. BARTON, Senior Lecturer in Sheep Husbandry and Wool, Massey Agricultural College, Palmerston North THE satisfactory disposal of New Zealand ewe mutton has always been difficult. • Consumers in New Zealahd and overseas have objected to ewe mutton mainly on the justifiable grounds that if carries too much fat and that it is too heavy and therefore it is not possible to cut light joints from such carcasses. Many times in the past ewe mutton has been extremely difficult to sell. For instance, just before 1939 there were about a million ewe carcasses in cold storage for. which no profitable outlet was available. The war provided an opportunity for the sale of this meat, but later because of a great shortage of refrigeration • ships a further crisis developed and again ewe mutton accumulated in the freezing works. This difficulty was overcome by canning much of this meat locally. Recently there has been a further difficulty over the sale of this meat. The British butcher and housewife were very reluctant to purchase New Zealand ewe mutton and only price reduction broke the deadlock.

PRODUCERS are now aware that . during 1954 the British Ministry of Food will return to private enterprise much of the latter’s former duties in regard to purchase, distribution, and sale of meat. This will almost surely mean changes in price relationships for various classes and grades of meat and could quite conceivably result in a lower return for meat which is not readily acceptable to the consumer. Ewe mutton, therefore, may drop in price while other classes of meat may remain at their present price level or even increase in price. Such a price adjustment affecting ewe • mutton could, as in the ' past, result in uneconomic returns to producers. New Grading Standards During the 1953-54 contract' meat price discussions the British Ministry of Food sought an assurance from the New Zealand Meat Producers Board that in future excessively fat mutton carcasses regardless of weight would be graded as manufacturing meat and paid for accordingly. To comply with this request the Meat Board has held a conference with its supervising graders at which standards were laid down so that grading will be uniform throughout the country. The Meat

Board seeks the full co-operation of ■producers in its attempt to remedy one of the main criticisms of this class of meat —overfatness. Ewe carcasses this season will be graded much more severely than in the past. Thus all ewe carcasses heavier than 721 b. frozen ' weight will not be exported in carcass form. Further, all carcasses under 721b.' frozen weight which are overfat will be graded as manufacturing meat and paid for at a lower price than those which can be exported in carcass form. The latter provision applies also to wether mutton. Meat prices for ewe mutton have for this season been adjusted to encourage the production of lighter carcasses. In seasons since 1950-51 there has been only one price for all carcasses up to 561 b. frozen weight, but in the 1953-54 season a higher price per pound will be paid for carcasses weighing 481 b. and under and a lower price for those weighing 49 to 561 b. Similarly for carcasses m the weight ranges above 561 b., there will be progressive price-per-pound decreases. Carcass Weights Ewe carcass weights have averaged 54.811 b. since the first figures were published in 1923. However, within the last few years there has been a

decided tendency for weights to increase in both the North and South Islands.

In the North Island the Wellington west coast district produces carcasses approximately 21b. heavier than the Auckland district and lib. heavier than Hawkes Bay and east coast. In the South Island the MarlboroughNelson district produces the lightest carcasses in the Dominion. Southland produces carcasses about 31b. heavier than those of any other district in the Dominion. Canterbury-Otago ewe carcasses are the next lightest to those of Marlborough-Nelson. Producers in districts with high average carcass weights should pay particular attention to the problem of overfatness and do everything possible to kill ewes in lighter condition.

These data represent a typical grading return for the entire ewe killing for one freezing works and closely approximate the Dominion situation for the percentages of carcasses ■ in each weight range. Thus about 16 per cent, of all ewes killed will receive the price premium of 0.93 d. per lb. on carcasses 481 b. and under. The percentage represents nearly 350,000 carcasses in a normal season’s killing. Fat in Carcasses As the carcass weight of ewes increases there is a natural increase in

the amount of fat. This is particularly noticeable in the depth of fat over the eye of the chop.

In a line of Romney crossbred ewes the amount of fat over the eye of the chop can vary from under Jin. to over l|in., as has been shown in experimental work at Massey Agricultural College. These ewes had been run on good country for 4 seasons. The amount of fat over the chop in the Southdown-cross fat lamb progeny of these ewes bore little or no relationship to the fat in their mothers. It is largely because of the increasing amount of fat in heavier carcasses that these are worth so much less per

pound. Most consumers do not like more than Jin. of fat round the chop and if there is more, it is left on the side of the plate. With fatty carcasses the butcher must trim off the excess fat before he can sell the joints and cuts. This trimmed-off fat is worth at present only about 2d. to 3d. per pound, but it has been purchased by the butcher at meat prices. The butcher, too, has to expend 5 to 7 minutes per carcass in trimming. It is thus quite clear that fat beyond an optimum is very wasteful to the butcher in time and money.

Excessive fat on mutton is more serious than on beef and pork. Beef and pork fat can be used for dripping and lard, whereas mutton tallow is used mainly in soap manufacture. Because of the rapid increase in the use of synthetic detergents soap made from tallow is being largely replaced in industry; consequently tallow prices are falling. ' Carcass Composition

These data are based on the complete dissection of 5 North Island and 5 South Island ewe carcasses in each standard weight range. This work was carried out at Massey and Canterbury Agricultural Colleges. It is quite clear from the figures in Table 4 that: — 1. From the lightest to the heaviest carcasses there is only a difference of 1.21 b. in bone weight. Bone thus forms a very small proportion of the total weight increase of the carcass. 2. Muscular tissue . weight increases less than 101 b. between carcasses under 481 b. up to carcasses as heavy as 801 b. 3. The fatty tissue in the carcasses increases markedly from 11.71 b. to 34.81 b. (23.11 b. over the whole carcass weight range. This illustrates clearly that the major factor affecting carcass weight is fat. Carcasses having more than say 151 b. of fat in them are wasteful to both the butcher and consumer, as much of the excess fat above this level is not or cannot be consumed. Management to Prevent Overfatness Producers are only too well aware of the difficulties of preventing overfatness in ewes, particularly those grazing on highly fertile land. Nevertheless it is definitely in farmers’ interests to make a determined effort to ensure that excessively fat ewes are not sent to the freezing works until a worthwhile attempt has been made to reduce their fatness. Observance of the following points in flock management should under most conditions eliminate a good deal of the trouble: — 1. Remove from the flock at the earliest opportunity all the dry ewes. These sheep can be managed in such a way as to prevent them becoming overfat. They can also be disposed Of when convenient, even early in the killing season. 2. Where possible, ewes should be drafted up into those likely to lamb early and those likely to lamb late. This can be done with a high degree of accuracy several weeks before lambing begins. The ewes which are thus sorted can be fed to the benefit of the early - lambing and frequently twin-bearing ewes. This will also help to minimise the incidence of sleepy sickness . because of the better feeding of the twin-bearing ewes. A further separation of ewes with twins at foot from those with singles can be

carried out as soon as possible after lambing. This practice aiming at the better feeding of ewes with twin lambs has beneficial effects on the milk supply of the ewes and the growth of their lambs, and should also provide an . opportunity to control to some extent the excessive amounts of fat which are put on more by the ewes with singles. 3. Early weaning will enable a much better check to be applied to the excessive fattening of ewes, since weaned ewes can be provided with limited amounts of food from this time on to flushing without harmful effects. Recent research, work at

Ruakura has shown that early weaning provides an opportunity to check the weight increases of the ewes, to enable better fattening of the lambs, and to provide an opportunity for early disposal of ewes to the works.

4. Ewes which are to be put to the ram can be kept in low condition on sparse feed during the period from weaning until 3 weeks before tupping. At this time they should be moved to saved pasture or crop to flush them. Flushing should continue for 5 weeks after the rams are joined with the ewes and thereafter the ewes can be done moderately hard again. In fact, restricted feeding of the ewes can continue to within 4 to 5 weeks of lambing without serious effects on the lamb. This policy ensures an adequate supply of feed for the last month of pregnancy, which is so important in producing vigorous lambs at birth and a good milk supply from the ewes. The practice of flushing ewes before and during mating results in a higher lambing percentage. and thus more ewes with twins. Ewes with twins do not become as fat after lambing as those with singles. The system of controlled feeding after tupping right through to within 4 to 5 weeks of lambing results in higher carrying capacity and therefore less-fat ewes. 5. High carrying capacity is important in preventing overfatness in ewes. Provided the carrying capacity bears a reasonable relationship to the pasture available, the higher it is the greater the production of wool and meat per acre will be. Since high production per acre is a sound guide to efficiency in farming, this should therefore 'be the aim of all producers. High carrying capacity, though leading to increased production per acre, almost invariably results in lower fleece and carcass weight per animal. This system of farming falls in with the modern demand for light-weight carcasses in lamb, mutton, and beef. Since light-weight carcasses are more valuable per pound than heavy-weight ones and greater production per acre is obtained as . the result of higher stocking rates, the producer is more than compensated for any consequent reduction in fleece weight. Greater Efficiency Needed For success in farming at high stock numbers per acre the farmer . must be more efficient in his pasture, crop, and stock management. It is only in this way that he can increase the productivity of his ■ farm and ensure that there will be no periods of severe feed shortage at critical times. Frequently ewes cannot be killed when convenient to the farmer owing to freezing works being fully booked with lambs. This situation makes it more important for the farmer to practise controlled feeding so that his ewes do not become overfat in the interval between weaning and slaughter. Excessive fatness in ewes leads to lowered fertility, diseases such as sleepy sickness and possibly bearing trouble, lambing difficulties, poor milk production, their , getting cast, deaths at shearing, and general sluggishness resulting in greater difficulty during mustering and droving. All these troubles can be overcome largely by paying attention to the principles of

efficient ewe management designed to safeguard ewes from becoming grossly fat. Conclusion The satisfactory disposal of ewe mutton is largely dependent on the amount of fat. on carcasses. Freezing works grading of this meat will penalise overfatness. This will result in lower returns for overfat carcasses. Trimmed-off fat has little sale value to the butcher and fatty meat is not wanted by the consumer. Animals excessively fat are inefficient pro-

ducers and their management can be difficult if losses are to be avoided. Overfatness and consequent heavy carcass weight can be regarded as an indication of too light a rate of stocking and thus lower per-acre financial returns. If it is not possible to bring about a marked improvement in the quality of ewe mutton in relation to fatness, this meat on the return to free marketing will be exceedingly difficult to sell. It may fall so low in price that there may be little profit left to the producers after processing, freight,

commission, and insurance charges are met. References “New Zealand Journal of Science and Technology”, vol. 33, sec. A, No. 5, pp. 1-15, E. A. Clarke and C. P. McMeekan (1952). New Zealand Meat Producers Board Annual Reports. Acknowledgment Acknowledgment is made to the management of the Aorangi works of Messrs. Thos. Borthwick and Sons (A’sia) Ltd. for the provision of material for photography.

Safety Attachment for Plough By J. O. WALLACE, Seed Production Officer, Department of Agriculture, Dunedin

FARMER killed when tractor overturns on steep country" — "Farm employee found crushed to death under capsized tractor". These and similar headlines appear in the daily newspapers with disturbing frequency, and any measures that will lessen the number of tractor accidents deserve the fullest consideration.

WITH the development of new land farming operations are continually pushing back into the more rugged country with steep siblings, and even in the tractor ploughing of developed land brought in with horses which could crab walk the very steep faces the danger of - tractor capsize is ever present. A common difficulty on such country is the downhill swing of the plough, which often causes a 3-furrow heavy tractor plough to turn no more than a relatively small furrow with the leading mouldboard. Under such conditions the natural tendency of the operator is to watch the performance of the trailing plough rather than give his undivided attention to the pathway for the tractor, and this is probably the indirect cause of many accidents. Confronted with the conditions described Mr. D. Graham, North Chatton, Southland, evolved the simple device illustrated and had it affixed

to his 3-furrow tractor plough, and it has proved so successful in every respect in preventing the downhill swing of the plough that it is recommended to readers similarly situated in the interests of tractor operating safety and the accomplishment of better ploughing. The illustration shows a short landslide cut from fin. steel plate and attached to the rear leg of the plough and to a short supporting stay welded on to the rear of this leg. Its length should be such as will not interfere in any way with the movement of the rear wheel. To this special landslide is bolted a half-moon plate cut from a disused plough coulter. This plate

cuts into the bottom of the furrow to a depth of 3in. and, being at the rear of the plough, enables it to hold 3 furrows on the steepest of sidlings that can be traversed with a tracklaying tractor. The country worked by Mr. Graham is heavy clay loam , overlying stiff clay. With a lighter soil type an Drove an advantmi/ deeper Cut may prove an aavanta £e. With the attachment, described the operator can give his undivided attention to the driving of the tractor, and on steep sidling country this is a great advantage in preventing tractor accidents.

North South Island Island lb. • lb. 1939-40 to 1943-44 . to . 55.76 1943-44 . 51.30 . 55.76 • 51.30 1944-45 to 1948-49 . to . 57.36 1948-49 . 54.74 . 57.36 54.74 1949-50 to 1952-53 . to . 57.40 1952-53 . 57.13 . 57.40 57.13

TABLE I—AVERAGE EWE CARCASS WEIGHTS

Carcass weight range lb. Percentage of 1951-52 carcasses 1952-53 48 and under .. 16.0 16.1 49-56 . .. .. 28.0 28.5 57-64 . . 26.3 29.0 65-72 ' ' .. .. 16.3 - 16.7 73 and over .. 13.4 9.7

TABLE 2—PERCENTAGE OF EWES IN EACH WEIGHT RANGE

Carcass Average depth weight range of fat over eye lb. in. 48 and under .. 4/16 49-56 . . 5/16 . 57-64 .. 6/16 65-72 .. 7 .. 8/16 73-80 . . .. 12/16

TABLE 3—DEPTH OF FAT OVER THE EYE OF THE CHOP

Carcass Bony Muscular Fatty weight range tissue tissue tissue lb. lb. lb. lb.. 48 and under .. 5.3 23.9 11.7 49-56 ... 5.6 26.3 18.0 57-64 . .. . . 6.0 29.9 ' 21.7 65-72 .. 6.5 33.4 ' 25.9 73-80 . . 6.5 32.6 34.8

TABLE 4—COMPOSITION OF EWE CARCASSES