Cross breed lambs are being studied by Bell, Madsen, Bennett, Madsen, and Schmutz (1) at Utah State Agricultural College to improve the meat producing abilities of range sheep. High quality rams are being bred to range ewes. The thiamine, riboflavin, and niacin content of lambs selected from the cross breeds being developed was determined in this laboratory. These lambs have a known nutritive history. Studies on thiamine content of lamb whose nutritive history was unknown have been made by McIntire, Schweigert, and Elvehjem ( 5 ) and Cover and Dilsaver ( 3 ) . The lambs used by Noble, Spear, and Turnbull ( 7 ) and NobIe, Gordon, and Selson (6) had a known breed and feed history.A study of the thiamine content of lamb chops, legs, shoulders, and stew meat is reported herein.
EXPERIMENTAL PROCEDUREThe lambs were selected at random from the large experimental herd of sheep in southern Utah, where they had been raised under good range conditions. First and second cross lambs from Rambouillet ram x range ewe (€L and Rz) and from Columbia ram x range ewe (C and C,) and first cross lambs from Targhee ram x GI ewes (TI) were studied. The lot of lambs that was taken directly from the range is designated as grass-fat, while the other lot was fed f o r 92, 93, and 97 days for the 1947, 1948, and 1949 lambs, respectively, on a grain mixture of dry molasses, beet pulp, whole barley or wheat, salt, and steamed bonemeal plus alfalfa hay. The grass-fat lambs were approximately fire and one-half months old, while the fed lambs were approximately nine months old.The uniformity of the lambs was shown by the similarity of their carcass grades and weights (Table 1). After the carcasses were aged f o r 7 days under commercial Conditions, they were cut into shoulder roasts, leg roasts, and 1-inch thick loin and rib chops, with the rest of the lean meat being used f o r stew meat. All cuts of meat were quick-frozen and cooking tests were completed with samples taken f o r analyses within a month. Corresponding cuts from the left and right sides were used f o r the raw and cooked samples, respectively. Duplicate determinations for thiamine, moisture, crude fat, and total nitrogen were made on samples from the muscle (longissimus dorsi) i n the raw and cooked chops and on samples from the raw and cooked legs, raw shoulders, and a 500-g. lot of stew meat after grinding. The f a t on the leg or shoulder was ground with the lean. The stew meat had most of the f a t removed before it was cut into 1 inch cubes and divided into 500-g. portions f o r freezing.The muscle of the chop was cut out, weighed, and then replaced in the chop f o r panbroiling at a temperature of 230" to 266" F.(110" to 130°C.) until medium done. After cooking the chop, the muscle was weighed and analyzed. The legs were roasted a t an oven temperature of 325"F.(163"C.) t o an internal temperature of 18O0F.(S2"C. medium done).I n cooking the stews, 500-g. portions of stew from each animal were cooked with 40 ml. and with 250 ml. of t a p water f o r 15 minutes in a pre...
