Copper sulfate and sodium selenite lipid-microencapsulation modifies ruminal microbial fermentation in a dual-flow continuous-culture system.

Undesirable interactions between trace mineral elements and ruminal contents may occur during digestion when mineral salts are supplemented. Antimicrobial effects of copper sulfate (CuSO4) may affect ruminal digestibility of nutrients when fed as a source of copper (Cu), while sodium selenite (Na2SeO3) may be reduced in the rumen to less available forms of selenium (Se). Our objective was to evaluate if protection of CuSO4 and Na2SeO3 by lipid-microencapsulation would induce changes on ruminal microbial fermentation. We used 8 fermentors in a dual-flow continuous-culture system in a 4 × 4 duplicated Latin square with a 2 × 2 factorial arrangement of treatments. Factors were CuSO4 protection (unprotected and protected by lipid-microencapsulation) and Na2SeO3 protection (unprotected and protected by lipid-microencapsulation). Treatments consisted of supplementation with 15 mg/kg of Cu and 0.3 mg/kg of Se from either unprotected or protected (lipid-microencapsulated) sources, as follows: (1) Control (unprotected CuSO4 + unprotected Na2SeO3); (2) Cu-P (protected CuSO4 + unprotected Na2SeO3); (3) Se-P (unprotected CuSO4 + protected Na2SeO3); (4) (Cu+Se)-P (protected CuSO4 + protected Na2SeO3). All diets had the same nutrient composition and fermentors were fed 106 g of dry matter/d. Each experimental period was 10 d (7 d of adaptation and 3 d for sample collections). Daily pooled samples of effluents were analyzed for pH, NH3-N, nutrient digestibility, and flows (g/d) of total N, NH3-N, nonammonia N (NAN), bacterial N, dietary N, and bacterial efficiency. Kinetics of volatile fatty acids was analyzed in samples collected daily at 0, 1, 2, 4, 6, and 8 h after feeding. Main effects of Cu protection, Se protection, and their interaction were tested for all response variables. Kinetics data were analyzed as repeated measures. Protection of Cu decreased acetate molar proportion, increased butyrate proportion, and tended to decrease acetate:propionate ratio in samples of kinetics, but did not modify nutrient digestibility. Protection of Se tended to decrease NH3-N concentration, NH3-N flow, and CP digestibility; and to increase flows of nonammonia N and dietary N. Our results indicate that protection of CuSO4 may increase butyrate concentration at expenses of acetate, while protection of Na2SeO3 tended to reduce ruminal degradation of N. Further research is needed to determine the effects of lipid-microencapsulation on intestinal absorption, tissue distribution of Cu and Se, and animal performance.

Effect of rumen-protected B vitamins and choline supplementation on health, production, and reproduction in transition dairy cows.

The objectives were to determine the effects of a rumen-protected blend of B vitamins and choline (RPBC) on the incidence of health disorders, milk yield, and reproduction in early lactation and the effects on gene expression and liver fat infiltration. A randomized controlled trial in 3 commercial dairy herds (n = 1,346 cows with group as the experimental unit; experiment 1) and a university research herd (n = 50 cows with cow as the experimental unit; experiment 2) evaluated the use of 100 g/cow per d of commercially available proprietary RPBC supplement (Transition VB, Jefo, St. Hyacinthe, Quebec, Canada), or a placebo, fed 3 wk before to 3 wk after calving. In experiment 2 liver biopsies were taken at 4 and 14 ± 1 d in milk to measure triacylglycerol concentrations and expression of 28 genes selected to represent relevant aspects of liver metabolism. Treatment effects were assessed using multivariable mixed logistic regression models for binary health and reproductive outcomes; linear regression models for milk yield, dry matter intake, and liver outcomes; and survival analysis for time insemination and pregnancy. In experiment 1, treatment did not have an effect on the incidence of hyperketonemia (blood ß-hydroxybutyrate ≥ 1.2 mmol/L; cumulative incidence to 3 wk postpartum of 28 to 30%), clinical health disorders, or udder edema. The prevalence of anovulation at 8 wk postpartum was 11% in the treatment group and 23% in the control but did not differ statistically given group-level randomization. Pregnancy at first insemination (33 and 35%) and median time to pregnancy to 200 d in milk (96 and 97 d) were not different between treatment and control, respectively. No difference was observed between treatment groups in milk yield or components through the first 3 Dairy Herd Improvement Association test days (44 kg/d in both groups, accounting for parity and components). In experiment 2, there were no differences between treatment groups in feed intake. Mean blood ß-hydroxybutyrate was lower at wk 3 in RPBC (0.6 vs. 0.9 ± 0.12 mmol/L) with no difference between treatments for mean blood concentrations of fatty acids (wk -1 or 1) and ß-hydroxybutyrate at wk 1 or 2. The gene for acyl-CoA oxidase 1 (ACOX1) had lower mRNA abundance in RPBC with no difference between treatments for the other genes, but the expression of half of the genes assessed differed with days in milk. Liver triacylglycerol was lower in primiparous cows at 4 d in milk in RPBC (2.0 vs. 4.4 ± 1.2%) but not at 14 d in milk (2.2 vs. 3.2 ± 0.97%) with no treatment effect in multiparous cows (4.6 ± 0.8%). Accounting for parity, days in milk, fat and protein percentages, repeated test days, and a random effect of cow, no significant difference was observed between treatments in milk yield across the first 3 Dairy Herd Improvement Association tests (41.2 ± 1.3 in RPBC vs. 38.0 ± 1.4 kg/d in control). Under the diet and management conditions of the field study including low prevalence of clinical health disorders, in experiment 1 we did not detect a benefit of RPBC, but in experiment 2 liver fat content decreased in primiparous cows.

Validation of a quantitative food frequency questionnaire for rapid assessment of dietary calcium intake.

This study tested the accuracy of a quantitative food frequency questionnaire (FFQ) designed to assess the amount of calcium consumed daily and to use as an educational tool in diet counseling and for prescribing calcium supplementation. The subjects were 26 perimenopausal women, aged 48 to 56 years, who were participants in a longitudinal osteoporosis study. Diets of the subjects were studied during the winter and summer of one year. Subjects filled out a food frequency questionnaire and the next week completed 4-day food intake records according to instructions from the researchers. The mean daily intake of calcium estimated from the food frequency questionnaire was 928 mg in the winter and 912 mg 6 months later. Ranges in the winter were 227 to 2,243 mg calcium and in the summer 198 to 3,063 mg calcium. The 53-item FFQ included descriptions of portion sizes and a calcium index for each item and had options for two frequency periods. The calcium level estimated from the questionnaire correlated (r = .73 in winter and r = .84 in summer) with the estimated amount from 4-day records. A seasonal difference was not found. The brief time (less than 5 minutes by a dietitian) required to calculate the amount of calcium consumed daily from the food frequency questionnaire could make it an important clinical tool.

Urinary N-nitrosamino acids as indices of endogenous formation of N-nitroso compounds.

Exposure to their precursors (e.g., amines, nitrate/nitrite, NOx) can lead to formation in the human body of N-nitroso compounds (NOC), a class of potent animal carcinogens, which are also suspected of being carcinogenic in man. A non-invasive method, the 'N-nitrosoproline (NPRO) test', for estimating endogenous nitrosation in man was developed in our laboratory. This test, which monitors 24-hr-excretion of urinary N-nitrosamino acids, is now applied in clinical and field studies, with the aim of measuring nitrosamine exposure and of identifying dietary, life-style, and host factors, or disease states, that affect nitrosation in man. Results from such studies are used to identify populations/individuals at high risk for cancers of the stomach, oesophagus, and oral cavity possibly caused by endogenous nitrosamines, and to indicate preventive measures by which the body burden of endogenous nitroso carcinogens can be lowered efficiently.

Dietary intakes of Title III meal program recipients and nonrecipients.

Nutrient intakes, dietary habits, and the nutrition knowledge and attitudes of elderly recipients and nonrecipients of a Title III meal program were examined. Mean intakes of energy and all nutrients except niacin and vitamin C were higher for recipients, although no statistically significant differences were found. High average intakes of protein, iron, vitamin A, riboflavin, niacin, and vitamin C were shown among all groups. Low individual intakes were found for energy, calcium, vitamin A, and thiamin. Men consumed significantly more protein, fat, and riboflavin than women. As age increased, intakes of fat, protein, iron, thiamin, and niacin decreased. More than 75% of all subjects had diets rated "fair" or "good." Percentages of kilocalories from protein were above the recommended levels for all groups, and percentages of kilocalories from fat were above recommended levels for all groups except recipient women. Neither the number of meals eaten alone nor living arrangements had a significant effect on the patterns of intake of the nutrients studied. Most of the subjects interviewed did not regularly take vitamin/mineral supplements. Of those who took supplements, most consumed adequate diets. No significant differences were found in the nutrition knowledge or attitudes of recipients and nonrecipients, although recipients had slightly higher scores. Nutrition knowledge scores were above 60% for all groups. Educational attainment was positively correlated with nutrition knowledge.