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Biomedical subjects

S R Lowry

Publications and source records attributed to S R Lowry.

30 records · Page 2Linked to original sources
PubMed1987

Induced non-enzymatic browning of soybean meal. I. Effects of factors controlling non-enzymatic browning on in vitro ammonia release.

Non-enzymatic browning was tested as a means of suppressing degradation of soybean meal (SBM) by ruminal microbes in five trials with in vitro ammonia release as the response criterion. Treatments imposed on SBM included reducing sugar source (xylose, glucose, fructose and lactose), reducing sugar level (1, 3 and 5 mol/mol SBM-lysine), pH (6.5, 8.5 and 10.0), dry matter (DM) content (65, 70, 75, 80, 85 and 90%) and varying lengths of heating time (0 to 90 min) at 150 C. Samples heated under conditions that promoted non-enzymatic browning gave greater (P less than .01) ammonia release suppression that when SBM was heated without these treatments. Xylose was the most reactive sugar, but extended heating of SBM containing glucose, fructose or lactose resulted in ammonia release similar to xylose. Increasing sugar level from 1 to 5 mol/mol SBM-lysine caused linear decreases (P less than .01) in ammonia release for xylose, glucose and fructose, but not lactose. Ammonia release was higher (P less than .01) at pH 6.5 than pH 8.5 and 10.0, and higher (P less than .01) at pH 9.5 than pH 10.0. Rate of non-enzymatic browning decreased when samples containing greater than 80% DM were heated. These results are interpreted to show that controlled non-enzymatic browning may be effective for reducing ruminal degradation of SBM.

Amines↗
PubMed1987

Induced non-enzymatic browning of soybean meal. III. Digestibility and efficiency of protein utilization by ruminants of soybean meal treated with xylose or glucose.

Trials were conducted to evaluate effects of non-enzymatic browning of soybean meal (SBM) on efficiency of protein utilization and N digestibility. In trial 1, 48 Suffolk-Finnsheep lambs (22 kg) were fed 80 d to evaluate efficiency of protein utilization for growth when supplemental protein was fed as urea (U), commercial SBM (CS), or commercial SBM (pH 8.5, 83% dry matter) containing xylose (3 mol/mol SBM-lysine) and heated 30 min (XTS-30) or 55 min (XTS-55). Diets containing graded levels of N from CS, XTS-30 and XTS-55 were fed. Response criterion was efficiency of protein utilization, plotted as gains of lambs fed test proteins minus gain of lambs fed U vs supplemental test protein fed. Efficiencies of protein utilization were .62, 1.27 and .91 for CS, XTS-30 and XTS-55, respectively. Protein from XTS-30 was used more efficiently (P less than .05) than that from CS. In trial 2, apparent digestibility of N from CS (97%) was higher (P less than .01) than XTS-30 (77%) and XTS-55 (82%) by Suffolk-Finnsheep lambs (27 kg). In trial 3, 60 mixed-breed steers (218 kg) were fed individually for 105 d to evaluate glucose as a reducing sugar. Glucose-treated SBM (GTS) was prepared by mixing glucose (3 mol/mol SBM lysine) with SBM, adjusting pH and dry matter content to 8.5 and 80%, respectively, and heating at 150 C for 60 min. Supplemental N sources were U, CS, GTS and a 50:50 mixture (protein basis) of corn gluten meal and blood meal (CGM/BM).(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1985

Protein supplementation of ammoniated roughages. III. Corncobs supplemented with a blood meal-corn gluten meal mixture--steer studies.

Two factorial experiments were conducted to investigate site and extent of organic matter (OM) digestion, nitrogenous fractions flowing at the abomasum and rates-of-passage in steers fed 0, 2 or 4 g NH3/100 g dry matter of treated corncobs supplemented with either a corn or a blood meal-corn gluten meal (BM-CGM) supplement. Rumen and total tract OM digestion coefficients were quadratically increased (P less than .05) and dietary N was quadratically increased (P less than .07) due to the main effect of ammonia. The main effect of protein supplement increased (P less than .05) postruminal OM digestibility, nonammonia N and dietary-N flow. Quadratic protein X ammonia interactions were noted for fluid flow, total-N flow, total amino acid flow and ammonia-N flow. Linear protein X ammonia interactions were noted for bacterial-N flow, which appeared to indicate that N utilization of the ammoniated corn-cob was improved by the inclusion of BM-CGM in the diet. Diet dry matter intake, fluid volume, rate of fluid passage, particulate mass and rate of particulate passage in rumen-fistulated steers were unaffected by either main effect. However, rumen fluid pH of steers fed BM-CGM was lower than that from steers fed the corn supplement.

Animal Feed↗
PubMed1983

Enhanced progesterone and pregnancy rate after gonadotropin administration in lactating ewes.

Estrus was induced during March and April in 50 lactating ewes that were 20 to 31 d postpartum. Following estrus induction, ewes were treated with either saline or human chorionic gonadotropin (hCG; 100 IU) on d 11, 12 and 13 after mating. Regardless of whether ewes were later diagnosed as pregnant or not, treatment with hCG increased serum progesterone concentrations compared with concentrations observed in saline-treated ewes on d 12, 14 and 16 after mating (P less than .01). Pregnancy rate was higher in ewes treated with hCG than that of ewes treated with saline (58 vs 29%; P less than 0.5). Data from the present study indicate that it is possible to increase pregnancy rate in lactating, anestrous ewes after artificially-induced estrus by administering hCG.

Animals↗
PubMed1983

Effects of selenium, vitamins, and ration fiber on placental retention and performance of dairy cattle.

One hundred and twenty Holstein cows were assigned to a randomized complete block design to determine effects of selenium, vitamins, and ration fiber on incidence of placental retention and other health and reproductive problems. The selenium treatment (50 mg selenium, 680 IU vitamin E) was administered as a single injection approximately 3 to 4 wk prepartum. The vitamin treatment (3 million IU vitamin A, 450,000 IU vitamin D3, 300 IU vitamin E) consisted of two injections, one administered at 3 to 4 wk prepartum and another at 2 to 3 wk postpartum. Fiber treatments were: control, 15.7% crude fiber; beet pulp, 19.3% crude fiber; and soyhull, 19.0% crude fiber. Feeding of experimental rations was begun 1 day postpartum, and the ration effect on placental retention was examined only at subsequent parturition. The overall placental retention rate of 28% was not affected by either selenium, vitamin, or combined treatments. Ration treatments did not affect the placental retention rate of 42% at subsequent parturition. Cows receiving the soyhull ration required fewer services per conception. Incidence of foot problems tended to be higher in the cows that received the combined selenium and vitamin A, D, E treatments. Supplemental selenium, vitamins A, D, and E, and ration fiber treatments did not reduce incidence of placental retention or improve most other health and reproductive measures.

Animals↗
PubMed1983

Relation of age, season, production, and health indices to iodine and beta-carotene concentrations in cow's milk.

Milk samples were collected from 82 Holstein cows during the 1st yr of a 2-yr study and from 44 of these again in the 2nd yr to determine relationships of iodine and beta-carotene concentrations in milk to age, season, placental retention, uterine infections, clinical mastitis, services per conception, and milk yield. Composite milk samples were collected twice weekly at the morning milking. Milk samples from each cow were pooled prior to analyses for the following three times: 1 to 7 wk and 8 to 14 wk postpartum in yr 1 and 1 to 6 wk postpartum in yr 2. Beta-carotene concentrations of milk were inversely related to milk yield and positively related to milk fat percentage. Concentrations tended to be higher for cows experiencing health problems, probably because of lower milk yields and the concommitent higher milk fat content. The relatively low milk iodine concentrations were not generally related to cow age, season of calving, milk yield, milk fat percentage, or to health and performance measures.

Age Factors↗
PubMed1982

Metabolic responses of the rooster after exogenous thyroid hormones.

Total sensible heat loss, O2 consumption, and CO2 production were monitored in 20 White Leghorn roosters (1.85 +/- .05 kg body weight) subjected to either saline, or triiodothyronine (20 micrograms/kg; T3), or thyroxine (50 micrograms/kg; T4) administered in a single dose. Treatment occurred after a 26-hr fast and the fast was maintained for the duration of the experiment. Plasma T3 concentrations in birds treated with T3 were higher than controls for an 8-hr period after treatment (P less than .01). Plasma T4 in birds treated with T4 was higher than controls for the 24-hr sampling period (P less than .01). Sensible heat loss, but not O2 consumption or CO2 production, was affected by treatment during the first 10 hr following treatment (P less than .05). Heat loss after T3 and T4 treatments did not differ; however, pooled results of the treated groups were higher than that of control (P less than .05). Heat loss, O2, and Co2 varied with time (P less than .001) during the 10-hr period following treatment or saline. Sensible heat loss was also affected by treatment during the period of 21 to 25-hr posttreatment (P less than .001). During that period, the heat loss after T4 treatment was greater than that after T3 (P less than .005). These data suggest that a single administration of either T3 or T4 can affect total sensible heat loss but not O2 consumption of CO2 production within 10-hr posttreatment in mature roosters.

Animals↗
PubMed1980

Relationship between early postpartum blood composition and reproductive performance in dairy cattle.

Blood samples were collected over 1 year from 115 postpartum Holstein cows to determine the relationship between blood composition and reproductive performance. Blood samples were collected from each cow at 14 to 21 days (sample 1) and 38 to 45 days (sample 2) postpartum. These samples were analyzed for packed cell volume, hemoglobin, total protein, calcium, phosphorus, magnesium, copper, zinc, and selenium. Blood composition varied little with lactation number and season, and relationships were not consistent for the two collection periods. Hemoglobin, packed cell volume, total protein and zinc were associated negatively and calcium and magnesium associated positively with at least one measure of milk yield. None of the blood components examined at the two collection periods had a consistent relationship to reproductive performance. The most important relationship was the positive relationship of selenium concentration at first collection period with services per conception and days open.

Animals↗