Composition Of Basal Diet Research Articles

Effects of Supplemental Iodine and Season on Thyroid Activity of White-Tailed Deer

Blood samples were taken at 6-8 week intervals from 18 captive, female white-tailed deer (Odocoileus virginianus borealis) over a 2-year period to examine circannual changes in serum thyroid hormones and the effects of 3 levels of dietary iodine (+0, +0.2, +0.7 ppm) added to a basal diet generally containing 0.26-0.29 ppm iodine. Iodine (I) supplementation of the diet did not significantly affect T4, FT4, body weight, reproductive performance, milk I concentration, serum T3 and T4 levels of offspring, or dry weight and I content of the thyroid gland. Total thyroxine (T4) levels were higher (P < 0.05) in early winter and spring than in late winter, summer, and fall, and showed a close relationship with cyclic changes in feed intake and body weight. Free T4 (FT4) levels were highly correlated (r = 0.74, P < 0.001) with T4. Total tri-iodothyronine (T3) did not follow a clear seasonal pattern. Serum T3 and T4 levels were higher (P < 0.05) in fawns than in adult does and in nonlactating does than in lactating does. These results indicated 0.26 ppm I in a diet consumed ad libitum was sufficient to meet requirements for growth and reproduction in white-tailed deer. J. WILDL. MANAGE. 47(1):45-58 Thyroid hormones, thyroxine (T4) and tri-iodothyronine (T3), affect a variety of physiological processes including lipid, carbohydrate, and nitrogen metabolism, calorigenesis, growth and development, nervous system function, and reproductive performance (Bernal and Refetoff 1977, Underwood 1977:280-284). Thyroid activity in white-tailed deer has been studied to better understand the ways in which deer respond to different nutritional and environmental conditions (Hoffman and Robinson 1966, Seal et al. 1972, Byrne et al. 1974, Bahnak 1978, Bubenik and Bubenik 1978, Seal et al. 1978a). It is well established that whitetailed deer undergo cyclic changes in food consumption, body weight, body composition, and metabolic rate (Silver et al. 1971, Holter et al. 1977, Moen 1978). The relationship between thyroid activity and deer physiology, including changes in metabolic rate, nutritional status, catabolic and anabolic states, age, and reproductive phenology is still not clear. Among the endocrine glands the thyroid is unique in that its function is dependent upon a specific trace element-iodine (I). Insufficient hormone production resulting from I deficiency can reduce surviv l and impair reproductive performance. The Great Lakes region is known to be a naturally I-deficient area (Eldridge 1924) with a history of endemic goiter in humans (Olin 1924, McClendon 1939) and domestic animals (McCollum 1957:391392) before I supplementation began in the 1920's. Little is known about the I content of natural vegetation in the Great Lakes region and to what extent I might be limiting for wild herbivores. This study examined thyroid activity and reproduc' Michigan Agricultural Experiment Station Journal Article 9986. Supported in part by the Michigan Department of Natural Resources through Federal Aid in Wildlife Restoration Project W-117-R. 2 Present address: Department of Zoology, Washington State University, Pullman, WA 99164-4220. J. Wildl. Manage. 47(1):1983 45 This content downloaded from 157.55.39.221 on Mon, 03 Oct 2016 06:25:24 UTC All use subject to http://about.jstor.org/terms 46 IODINE AND THYROID IN DEER * Watkins et al. Table 1. Composition of basal diet used for iodine studies with white-tailed deer.

The Value of Menhaden Fish Meal in Practical Broiler Diets

CONSIDERABLE data have been accumulated concerning the value of fish meal as an ingredient for broiler diets. It has been reported that fish meal contains an unidentified factor necessary for maximum chick growth. The literature concerning the unidentified factor contained in fish meal has been extensively reviewed by Menge et al. (1952), Branion and Hill (1953), and Rasmussen et al. (1957). Summers et al. (1959) reported that fish meal was not a satisfactory source of the unidentified factor, and that the unidentified factor response was not influenced by the levels of corn and wheat in the diet. The present experiments were designed to study the value of fish meal in practical broiler diets containing various levels of protein and energy and/or in the presence of different levels of supplemental methionine and glycine. The composition of basal diets used in these experiments is shown in Table 1.…

Supplementation of Poult Diets with Lysine

Baldini et al. (1954) and Baldini and Rosenberg (1954) found that supplementation of poult diets containing about 20% protein with l-lysine increased growth rate. In at least one experiment, a 20% protein basal supplemented with lysine, and a 28% protein basal, gave about equal average gains to 6 weeks of age. Furthermore, both the ratio of the feed consumed to gain and the protein consumed to gain were smaller on the lysine supplemented diets. In all reported studies, Baldini and his co-workers used Jersey Buff poults and a corn and soybean type of diet. Breed and composition of basal diet are likely to be important factors influencing the results of this kind of experiment. Consequently, it is considered worthwhile to present the results of an experiment using Broad Breasted Bronze poults and diets containing considerable wheat and some protein from animal sources.Sexed day-old poults were allotted to 5 treatment …