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This article was published in 1951
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INSTITUTE OF INSPECTORS OF STOCK OF N.S.W. YEAR BOOK.
Recent Advances in Nutrition
G.L. McCLYMONT, Ph.D., B.V.Sc., Veterinary Research Officer, Glenfield.
"Animal Protein Factor"—Vitamin B12.
The difference in response of poultry and pigs to vegetable and animal protein concentrates is largely due to the vitamin B12 (and perhaps other related vitamins) content of animal products. Vegetable protein diets supplemented with vitamin B12 concentrates give results equal to those with animal protein concentrates.
However, our major problem here is shortage of all protein concentrates, not only those of animal origin, so that there is as yet no great indication for application of this knowledge here. However, the adequacy of our animal protein supplements in B12 is being investigated.
Growth Stimulation of Antibiotics.
Inclusion of antibiotics such as penicillin, aureomycin and streptomycin in even first-class diets has been found to stimulate growth of poultry and pigs. Crude preparations of antibiotics are being used commercially in the U.S.A. and are being investigated by the Department here. The materials also seem to control some obstinate forms of scours in pigs. The mechanism of action is not known. There is no immediate possibility of local production.
Bracken Fern Poisoning and Thiamin (vitamin B1).
Bracken fern poisoning of cattle appears to be due to an anti-thiamine factor in the fern. Treatment of cases with several injections of 100 mg. of thiamine has been reported to be successful.
Vitamin E and Nutritional Encephalomalacia of Chickens.
Although vitamin E prevents, and cures early cases of this condition, it is not an uncomplicated deficiency of this vitamin, but appears to be due to oxidation processes developing in the feed. A synthetic diet, completely devoid of vitamin E will not reproduce the disease. Adding lucerne meal or much to be preferred, fresh green feed to a diet in which it is encountered by providing the anti-oxidants ascorbic acid and xanthophyll, as well as vitamin E, should help to control outbreaks. Green feed is a far richer source of vitamin E than whole grains, contrary to some accepted ideas.
Riboflavin and Hatchability.
Although hatchability probably will be maximal on diets with riboflavin replacing all natural B complex-rich feeds such as liver meal and milk powders, the viability of the chickens may not be as good as where some such natural B complex-rich feeds are in the diet. Requirements of some vitamins,e.g., pantathenic acid, are higher for maximal viability than for maximal hatchability. Synthetic riboflavin should be used to supplement the riboflavin of natural B complex-rich foods—not completely replace it.
High Bone Content Meat Meals and Perosis.
The high bone and low protein content of some meat meals may lead to perosis due to manganese being immobilised by the high bone content. Manganese sulphate, 4 ozs. per ton of feed, will overcome such trouble.
Limestone as a Calcium Supplement for Poultry.
Experiments at Seven Hills have shown that ground limestone or limestone chips, fed from hoppers, can satisfactorily replace shell grit as a calcium supplement for laying birds.
Grain Sorghum Deleterious in Chicken Diets.
Although quite satisfactory in laying diets, grain sorghum in chicken diets can lead to slow growth and high mortalities and should be advised against in such rations. The effect is not due to any deficiency in grain sorghum.
Treatment of Linseed Meal for Chicken Diets.
Linseed meal in excess of about 10 per cent. in chicken diets is toxic. However, if well dampened with water, left 24 hours and then dried, the toxic material, an anti-pyridoxine factor, is destroyed and up to 30 per cent. then can be fed if necessary.
Lucerne Meal in Chicken Diets.
Over 5 per cent. of some samples of lucerne meal can depress appreciably the growth of chickens; a saponin apparently being responsible.
Deep Litter and Vitamins.
Growth of chickens or hatchability of eggs is better with birds on deep litter where the diet is deficient in B vitamins, such as riboflavin. The high level of bacterial activity in deep litter results in considerable vitamin synthesis in the litter.
Osteodystrophia Fibrosa and Ca-P Ratio.
The recent occurrence of this disease in two Arab brood mares on a diet of cereal chaff, oats and bran, emphasises that such cereal diets are very deficient in calcium, as they are for sheep, with a Ca-P ration of about 1:3 instead of the ideal 2:1: 10 lb. of lucerne hay or ¼lb. ground limestone should be included in the diet of hand-fed brood mares to ensure adequate calcium.
B Vitamins and Reproduction In Pigs.
The B complex content of the diet is of extreme importance in obtaining highest viability and growth rates in litters. High levels of lucerne meal or green feed, or milk powders or liver meal should be included in the diet of brood sows not receiving separated milk. The diet from three weeks before farrowing to farrowing seems to be even more important in this respect than the diet after farrowing.
Vitamin A and Goitre In Newborn Lambs.
Observations in the Burdekin Drought Feeding Research Unit (run jointly by the C.S.I.R.O. and Glenfield) suggest that vitamin A deficiency of ewes can cause high neo-natal lamb mortality with some of the lambs showing enlarged thyroids, although this it apparently not constant. A review of case histories of lamb mortalities associated with goitre in N.S.W. has shown that practically all these cases have been associated with drought conditions; and thus vitamin A deficiency. There is some indication that increasing the vitamin A intake of ewes even a month before lambing may not correct the effect of the deficiency on the lamb.
Trace Element Deficiencies.
Unthriftiness in sheep, particularly weaners, in recent seasons, despite high rainfall, led to suggestions of trace element deficiencies. Experiments at Grenfell and by a private practitioner near Dubbo have as yet failed to show any response to copper and cobalt supplements. Worm infestation has been found to be in many cases the major factor causing unthriftiness. The work at Grenfell is to be repeated as it is known that manifestations of these deficiencies can be highly erratic, being more likely in flush seasons such as have been experienced recently. Enzootic ataxia, due to copper deficiency, is strongly suspected on properties in the Gulargambone area, and experiments are in progress. Trace element deficiency should be suspected only when all other possible causes of unthriftiness such as quantity and quality of teed, and internal or external parasites have been eliminated as far as possible. Copper analyses are relatively simple and can be provided now where deficiency is suspected. Cobalt analyses, being very time-consuming, should be requested only when absolutely necessary. Samples for trace element analyses are only of value where the suspected deficiency is operating at the time. Both liver and pasture samples should be provided. Livers should be wrapped in a cloth damped with 10% formalin and not contaminated by dirt or contact with metal.
Metabolic Diseases.
American research, still in progress, indicates that massive, near toxic, doses of vitamin D2, given about a week before calving, may be of value in preventing milk fever in cows which regularly develop this condition.
Cortisone has given promising results in treatment of acetonaemia in cattle, but the material is not yet available for veterinary use.
The Nutrition Research Laboratory, Glenfield Veterinary Research Station.
Equipping and plans for staffing the laboratory are proceeding. The planned role of the laboratory is:—
(a) To assist in diagnostic and investigational work by analyses of blood, tissues and plant matter for such materials as copper, cobalt, glucose, ketones, vitamin A, cholesterol,etc.
(b) To provide analyses in connection with field experiments, such as protein and fibre contents of pastures and feeds, riboflavin content of poultry feeds, investigations of the toxic material in grain sorghum,etc.
(c) To carry out intensive research on specific problems; in particular, at present, the metabolic disease of sheep and cattle. This work will involve fundamental research on ruminal digestion and the endocrinology and metabolism of ruminants; and co-operation with field officers and private practitioners in experimental treatments.