IMPROVED MILBOND-TX® “OVERCOMING THE DETRIMENTAL EFFECT THAT VANADIUM HAS ON BROWN EGG SHELL PIGMENTATION”
In the previous issue of Milwhite’s Journal the topic of discussion highlighted the research conducted at the University of Florida, Gainesville, Florida (USA) with broiler breeders and Hy-Line Brown commercial egg-type layers documenting the depigmenting ability that vanadium (V) has on brown shelled eggs. These researchers fed V concentrations of 0, 15 and 30 mg V/kg diet in a corn soybean meal diet to Hy-Line Brown layers. These dietary concentrations of V were used because the researchers felt that even if diets were supplemented with a poor quality feed-grade phosphate source, the phosphate source would normally not contribute more than 30 ppm V to the diet. On days 3, 6 and 9 of a nine day period in which the three experimental diets were fed, each of the shells of the eggs collected from Hy-Line Brown egg-type laying hens was analyzed for their pigmentation by a computer color vision system. This established the base-line egg shell pigmentation for eggs laid by hens fed each dietary treatment.
A significant decrease in egg shell pigmentation was observed to occur by day 3 and continued until day 9 when the diets were changed to diets containing three different antioxidants to determine if the antioxidants would restore the brown color to the egg shells. Assisted by the computer color vision analysis system the researchers were able to determine the actual cause of the depigmentation “bleaching” effect which occurred in the egg shells. Vanadium caused a reduction in the “red” component of the egg shell rather than the “yellow” component. Also, these researchers were able to determine the influence that V had on eggs with different “shades” of shell coloration (i.e., dark brown vs. light brown). When V was added to the diets of hens laying eggs with dark or light brown shells, the magnitude of decline in pigmentation was essentially the same. On day 9, the diets were changed so that the hens receiving the V supplemented diets received a diet also supplemented with one of the following antioxidants: none, 100 mg vitamin C/kg, 100 IU vitamin E/kg, or 100 mg beta-carotene/kg. Eggs collected on day 3, 6, 9, 12, and 15 following the diet change were used for shell color analyses.
Results of the above experiment indicated that when vitamin C, vitamin E, and beta-carotene, were supplemented to the diets containing either 15 or 30 mg V/kg, only vitamin C totally restored egg shell pigmentation. Vitamin E and beta-carotene had no influence on restoring pigmentation to the egg shells. Further analysis of the data indicated that vitamin C restored the “red” component of the egg shell. Supplementing the antioxidants alone or in combination to the corn/soybean meal control diet containing no V had no effect on egg shell pigmentation.
Whether V is directly involved in enzyme or cofactor inhibition within the tubular gland cells of the uterus, which results in deposition of less pigment in the shell, or it modifies the pigment molecules structurally at other sites before being delivered to the shell gland for deposition is not known. Also, the exact mechanism responsible for the complete restoration of egg shell pigmentation by vitamin C is not known. However, unlike vitamin E and beta-carotene being lipid soluble, vitamin C was the only supplemental antioxidant that was water soluble. This may have been a contributing factor because, being water soluble, vitamin C was more available to directly prevent or assist in preventing V induced oxidative damage associated with enzyme-catalyzed pigmentation reactions occurring in the cytoplasm of the uterine (shell gland) cells.
If a crisis situation occurs and the use of a poor quality high-V phosphate source is unavoidable, egg producers should expect to see a deterioration of egg albumen quality in eggs from hens laying white or brown shelled eggs and also decreased shell pigmentation in brown eggs. However, we now know that research data in the scientific literature clearly document that supplementing 100 mg vitamin C/kg diet will restore egg albumen quality in situations where hens are consuming diets containing 30 mg V/kg or less. Also, in a field situation, the “bleaching” effect of brown egg shells which occurs when brown egg-type laying hens consume a diet containing 30 mg V/kg or less can be overcome. A complete restoration of normal egg shell pigmentation would be expected when vitamin C is supplemented to the diet at 100 mg vitamin C/kg. Data collected in other experiments by Florida researchers have shown that supplementing 100 mg vitamin C/kg diet “before” or “at the same time” or “after” V is introduced to the diet will prevent a decline in egg shell pigmentation. The next issue of Milwhite’s Journal focuses on shell pigmentation and explains why pigmentation decreases as hens age.
The information presented in this issue of Milwhite’s Journal was compiled by Dr. Orlando Osuna, Director of Health Science at Milwhite, Inc. and Dr. Richard Miles, Professor Emeritus, University of Florida, Gainesville, FL, USA.
Odabasi, A.Z., R.D. Miles, M.O. Balaban, K.M., Portier, and V. Sampath. 2006. Vitamin C overcomes the detrimental effect of vanadium on brown eggshell pigmentation. J. Appl. Poult. Res. 15:425-432.