EFFECTS OF IRON SUPPLEMENTATION ON THE PERFORMANCE, BLOOD HEMOGLOBIN,IRON CONCENTRATION AND CARCASS COLOR OF VEAL CALVES

The effects on the performance, blood hemoglobin, iron concentration a nd carcass color of an extra 25 ppm of iron (II)-fumarat added to a co mmercial milli replacer, given until the 38th day of the trial, were s tudied during a fattening period of 79 days on two groups of 24 calves . Two weeks, four weeks and 41 days after the withdrawal of the supple mental iron 14, 18 and 16 calves were slaughtered, respectively The di etary regimen had a significantly positive impact on the fattening per formance only within the time when the milk replacer was supplemented with extra iron. The feed efficiency was also clearly improved, The ef fects of tile supplementation on the progression of the iron concentra tion and blood hemoglobin values were reflected in the visual assessme nt of the carcass color of the surface muscles. Because of the results obtained in the first experiment, a second feeding trial was conducte d with 48 calves which were divided into two groups. The commercial mi lk replacer fed to the experimental group was supplemented with 25 ppm of iron(II)-fumarat, After six weeks the experimental group was split into two subgroups (2a and 2b) with 12 animals each, whereas only the milk replacer for group 2a was supplemented with 15 ppm of iron(II)-f umarat, During that time (29 days), the milk replacer used was a 50/50 % mixture of a commercial product and a milk replacer containing 53,7% they powder, 14,5% soyprotein and 4,5% potato protein as protein sour ces. Contrary to the results of the first experiment, no significant d ifferences in average daily gain were found between the two groups dur ing the first fattening period (36 days). Supplemental iron had a posi tive influence on the feed conversion within the first 6 weeks. A sign ificantly higher average daily growth performance was only observed in group 2a, which was fed supplemental iron until the end of the experi ment. The apparent digestibility of iron was also markedly higher in g roup 2a. In contrast to the findings made in experiment one, no change . in the blood hemoglobin and iron concentration was observed. Supplem enting iron during the whole fattening period did not negatively affec t the veal color. It is concluded that an extra iron supplementation t o the commercial milk replacers can improve the fattening performance without necessarily having a detrimental impact on the color of veal, although it must be noted that the meat color depends on the amount of iron supplemented and an the length of time it is administered.