The effect of the level of roughage, diethylstilbestrol, and iron on certain blood components in growing beef

In the first study 30 Hereford steers were fed a ration of either steam rolled barley or a 50:50 mixture of barley and alfalfa leaf meal pellets. In addition to these basal rations groups of animals on each, were fed a protein supplement with Diethylstilbestrol (D.E.S.) at levels such that each animal received either 0, 10, or 18 mgm. of D.E.S./head/day. The hormone treatment of animals fed the barley ration did not affect the growth rate or feed efficiency but a significant increase in hemoglobin levels from 8.96 to 10.40 gm. % Hb. and in the red cell counts from 8.25 million/mm³ to 9.50 million/mm³ resulted. A similar increase in red cell count from 8.7 million/mm³ to 9.6 million/mm³ resulted from hormone treatment of the animals fed the 50:50 barley-alfalfa ration. There was also an apparent, but insignificant, increase in haematocrits on both rations due to hormone treatment. This treatment resulted in a significant increase in the ratio of blood acetic to propionic acids on the barley ration from 82.3:1 to 195.3:1 but, did not cause a change in total blood volatile fatty acids (V.F.A.). There was an increase in the blood acetic-propionic ratio on the barley-alfalfa ration due to D.E.S. addition. This was from 97:1 to 159:1 at 10 mgm. D.E.S./head/day, to 233:1 at 18 mgm. of D.E.S./head/day but, was insignificant due to high within-group variability. There was an apparent difference between the three blood parameters (Haematocrit, Hemoglobin, Red Cell Counts) on the two control rations due to the higher iron content of the barley-alfalfa ration. This, and an apparent decrease in thyroid weights were shown to be insignificant. In the second study, using an all barley ration and a protein supplement containing a high iron concentration, there was a stimulation in growth rate and feed efficiency due to D.E.S. The animals were started on D.E.S. at 718 lb. (cf. 465 lb. for Study I). The increase in the three blood parameters was again observed on the low iron rations but, on the high iron ration there was an apparent but insignificant decrease in these parameters due to D.E.S. The animals fed the control high iron ration produced an haematocrit and red cell count that was significantly higher than that of the control low iron ration, indicating a possible deficiency in the original supplements. On the low iron ration there was a significant increase in total blood V.F.A. from 0.88 meq./l. to 1.19 meq./l. in response to D.E.S. supplementation but, on the high iron ration the increase was insignificant. The difference between the two control rations (0 D.E.S., high and low iron) total blood V.F.A. was shown to be significant, 0.88 vs. 1.08 meq./l. at P< .05. A method of preparation of feed and liver samples for analysis of their mineral content by atomic absorption spectrophotometry was developed. There was shown to be a significant increase in liver copper storage on the low iron ration with increased levels of D.E.S. The feeding of a high iron ration caused a significant decrease (P< .05) in the level of copper in the liver from 84 ppm. to 37 ppm. A slight but insignificant increase in liver iron levels on the high iron ration and through the treatment with D.E.S. was observed.Land and Food Systems, Faculty ofGraduat