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K C Hanson

Publications and source records attributed to K C Hanson.

9 recordsLinked to original sources
PubMed2006

Effects of a dietary Aspergillus oryzae extract containing alpha-amylase activity on performance and carcass characteristics of finishing beef cattle.

Three experiments were conducted to examine the effects of an Aspergillus oryzae extract containing alpha-amylase activity on performance and carcass characteristics of finishing beef cattle. In Exp. 1, 120 crossbred steers were used in a randomized complete block design to evaluate the effects of roughage source (alfalfa hay vs. cottonseed hulls) and supplemental alpha-amylase at 950 dextrinizing units (DU)/kg of DM. Significant roughage source x alpha-amylase interactions (P < 0.05) were observed for performance. In steers fed cottonseed hulls, supplemental alpha-amylase increased ADG through d 28 and 112 and tended (P < 0.15) to increase ADG in all other periods. The increases in ADG were related to increased DMI and efficiency of gain during the initial 28-d period but were primarily related to increased DMI as the feeding period progressed. Supplemental alpha-amylase increased (P = 0.02) the LM area across both roughage sources. In Exp. 2, 96 crossbred heifers were used in a randomized complete block design with a 2 x 3 factorial arrangement of treatments to evaluate the effects of corn processing (dry cracked vs. high moisture) and supplemental alpha-amylase concentration (0, 580, or 1,160 DU/kg of DM). Alpha-amylase supplementation increased DMI (P = 0.05) and ADG (P = 0.03) during the initial 28 d on feed and carcass-adjusted ADG (P = 0.04) across corn processing methods. Longissimus muscle area was greatest (quadratic effect, P = 0.04), and yield grade was least (quadratic effect, P = 0.02) in heifers fed 580 DU of alpha-amylase/kg of DM across corn processing methods. In Exp. 3, 56 crossbred steers were used in a randomized complete block design to evaluate the effects of supplemental alpha-amylase (930 DU/kg of DM) on performance when DMI was restricted to yield a programmed ADG. Alpha-amylase supplementation did not affect performance when DMI was restricted. We conclude that dietary alpha-amylase supplementation of finishing beef diets may result in increased ADG through increased DMI under certain dietary conditions and that further research is warranted to explain its mode of action and interactions with dietary ingredients.

Animal Feed↗
PubMed1984

Long-term effects of low histidine intake on men.

The purpose of this 85-day study was to investigate the long-term effects of histidine depletion on nitrogen utilization in young adult men. A low nitrogen (6.3 g/day), low histidine (10 mg/day) amino acid diet was fed to seven men for 8 weeks. Mean nitrogen balance became negative at the end of the 8-week period. Free histidine in postabsorptive plasma and 24-hour urine decreased significantly during the first 2 weeks of the depletion and remained low and constant for the remaining 6 weeks. Hemoglobin concentration decreased somewhat, and serum iron concentration increased significantly during histidine depletion. Lean body mass, urinary N'-methylhistidine and total creatinine did not change significantly. On addition of histidine to the low histidine diet for 2 weeks, nitrogen retention became positive, plasma and urinary histidine returned to initial values, serum iron fell, and hemoglobin concentration slowly increased. These parameters remained unchanged in two control men fed the same diet supplemented with histidine (1.05 g/day) for 8 weeks. The results suggest that histidine is indispensable for young men consuming a low nitrogen diet.

Adult↗
PubMed1977

Effects of dietary histidine and arginine on nitrogen retention of men.

Effects of dietary histidine and arginine on nitrogen retention were compared in six young men consuming for 1 week, each of six semipurified diets containing eight indispensable amino acids proportioned as in casein and 6.3 g nitrogen daily. Nonspecific nitrogen was either A) a mixture of six dispensable amino acids and arginine (diet 1) or arginine and histidine (diet 2) in casein proportions, or B) an isonitrogenous mixture of glycine and diammonium citrate alone (diet 3), with histidine (diet 4), arginine (diet 5), or histidine and arginine (diet 6). Nitrogen retention was significantly greater when the nonspecific nitrogen source was dispensable amino acids, arginine and histidine (diet 2) than when it was glycine and diammonium citrate (diet 3). mean balances were positive only when diets contained histidine (diets 2, 4, and 6). Histidine with arginine (diets 2 and 6) significantly improved nitrogen retention compared to arginine alone, but the balance, although positive, was not significantly improved when histidine was fed without arginine (diet 4). Urinary urea nitrogen confirmed these data. Indicators of erythrocyte status, plasma enzyme activities and proteins, and creatinine clearance were unaffected by diet. In summary, histidine supplementation of the low nitrogen diet improved total nitrogen utilization when arginine was present in the diet.

Adult↗
PubMed1972

Effect of bile salts on hepatic phosphatidylcholine synthesis and transport into rat bile.

The effect of transport of micelle-forming and non-micelle-forming conjugated bile salts on phosphatidylcholine synthesis and transport into bile was studied in the ex vivo perfused rat liver. Single additions of sodium taurocholate, a good micelle-forming conjugated bile salt, caused an increase in bile flow associated with increased phosphatidylcholine and taurocholate concentration. The specific activity of phosphatidylcholine with respect to incorporated [1,2-(14)C]choline and [(3)H]methyl of l-[Me-(3)H]methionine was not significantly altered by the increased transport of phosphatidylcholine. The data suggested that bile phosphatidylcholine is synthesized to a great extent, although not exclusively, by phosphorylcholine glyceride transferase. Single additions of the glycine conjugate of dehydrocholate, a poor micelle-forming bile salt, caused an increase in bile flow comparable to that seen with sodium taurocholate administration. However, the concentrations of phosphatidylcholine in bile decreased. Thin-layer and gas-liquid chromatographic analyses of bile secreted before and after glycodehydrocholate administration revealed no significant increase in bile salt secretion other than the administered glycodehydrocholate. Investigations utilizing radiochemically pure [(14)C]glycine dehydrocholate revealed that increased bile flow after [(14)C]-glycine dehydrocholate administration occurs concomitantly with the secretion of 75-95% of the administered [(14)C]glycine dehydrocholate as a single peak into bile. Thus the increased bile flow without increased phosphatidylcholine concentration noted after glycodehydrocholate administration is due to transport of an intact, nonmetabolized, conjugated bile salt with poor micelle-forming properties. The data indicate that the formation of a bile salt-phosphatidylcholine micelle is responsible for phosphatidylcholine transport into bile.

Animals↗