ANIMAL NUTRITION.

New Zealand Herald, Volume LXVIII, Issue 20867, 8 May 1931, Page 17

ANIMAL NUTRITION.

INFLUENCE OF lODINE. I Research in '.connection with the part played by iodine in animal nutrition is proceeding and, while the evidence obtained from experiments appears to be somewhat) conflicting, it is none the less true that, as scientific inquiry progresses tho importance of tho iodino factor in nutrition becomes more strongly established. A paper on "Jodine in Practical Agriculture," contributed to the In-" ternational Review of Agriculture, by Brs. Orr and Leitch, of tho Rowett Institute, makes interesting reading and contains a great deal of information well worth tho study of any agriculturist. In one section dealing with the effect of iodino on milk yield, reference is made to an experiment commenced at the Rowett Institute with two groups of Ayrshire cows, v fed on a ration containing no food known to bo high in iodine, but otherwise well balanced. Ono of tho groups is receiving 90 milligrammes of iodine a head daily. At the time of tho report the experiment was approaching the completion of the second lactation, and it is interesting to note that tho milk yield in the control group (without iodino) in the second year is below expectation, while in the iodine group it is well above expectation (almost 10 per cent.) at 240 days, and there are indications that this difference will be continued to tho end of tho lactation. Tho report goes on to say that it is of particular interest to note that this considerable increase in milk yield is not associated with a reduction in fat percentage. This agrees with the ..findings of the Continental worker, Stiner, who found that iodino feeding caused an increase in milk yield accompanied by ;in increase in fat and total solids. In a later section of tho paper tho authors give information of even greater interest, not to say significance. At the 'commencement of tho experiment all the cows wo.ro tested for contagious abortion. The controls were all negative, but three of the cows in the iodino group gave a positive reaction. In spite of this, during the first pregnancy of the trial, three of the control cows aborted, one gave birth to a premature calf Which died, and only five calves were got from this group. Tho ' iodine-fed cows produced • nine nealthy calves. Further, the condition of this group was throughout superior to that of tho control group. c Such observations suggest, at least, as the authors say, that iodine administration may have had an effect in increasing the power of the animal to resist infection.