Metabolic responses of lactating dairy cows to exogenous glucagon

Fatty liver is a major metabolic disorder of dairy cows in early lactation that compromises their health status and reproductive performance and in clinical cases decreases milk production and feed intake. Fatty liver can be treated with 14-d continuous, intravenous infusions of 10 mg/d of glucagon. The objective of the current study was to test whether treatment of fatty liver with 14-d subcutaneous injections of glucagon at 7.5 or 15 mg/d, which is more practical than infusion, would cause similar metabolic responses and improve health status and reproductive performance of dairy cows in early lactation. In the main study, multiparous Holstein cows (n = 32) were grouped on the basis of their liver triacylglycerol concentration at d 8 postpartum into Normal (n = 8; triacylglycerol \u3c 1% liver wet wt) and Susceptible (n = 24; triacylglycerol \u3e 1% liver wet wt) cows. Susceptible cows were assigned randomly to three groups and beginning at d 8 postpartum received 0 (same for Normal cows), 2.5, or 5 mg of glucagon in 60 ml 0.15 M NaCl by subcutaneous injections every 8 h for 14 d. Subcutaneous injections of 15 mg/d of glucagon consistently increased concentrations of plasma glucose and insulin for 4 h, decreased concentrations of liver triacylglycerol in cows older than 3.5 years, and tended to decrease concentrations of plasma NEFA and BHBA. The effects of 15 mg/d of glucagon were not limited to the treatment period, because glucagon decreased the incidence of mastitis and days to first ovarian activity after the injection period. These results document that subcutaneous injections of 15 mg/d of glucagon improve metabolic status throughout the injection period and have the potential to treat fatty liver in older cows. The improved metabolic status in cows treated with 15 mg/d of glucagon in early lactation has long-term beneficial effects by improving health status and reproductive performance during the entire lactation

Grain Legume Consumption Inhibits Colorectal Tumorigenesis: A Meta-Analysis of Human and Animal Studies

Grain legume consumption has been linked in meta-analysis studies to decreased risk of metabolic syndrome, obesity, and cardiovascular diseases; however, the evidence for a chemo-protective effect of grain legume consumption against colorectal tumorigenesis has been considered inconclusive. We conducted a meta-analysis of human and animal studies to evaluate the effect of grain legume consumption on colorectal cancer (CRC) and its precursors. Twelve case-control studies (42,473 controls and 12,408 cases) and 11 prospective cohorts (1,533,527 participants including 12,274 cases) were included in the meta-analysis; the pooled risk ratio (95% confidence interval) for the highest versus the lowest legume intake group based on a random effects model was 0.72 (0.60–0.89) for incident adenoma, 0.91 (0.84–0.99) for prevalent adenoma, and 0.82 (0.74–0.91) for CRC. Fourteen animal studies (355 animals on grain legume diets and 253 animals on control diets) were included in the meta-analysis and showed in all but one study a chemo-preventive effect against colorectal tumorigenesis. Grain legumes contain various compounds (e.g., resistant starch, soluble fiber, insoluble fiber, phytosterols, saponins, phytates, flavonoids, proanthocyanidins, and phenolic acids) that have been shown to inhibit colorectal tumorigenesis in animal studies at concentrations that are relevant for human diets. Grain legume consumption alters several molecular pathways (e.g., p53, mTOR, NF-kB, Akt, and AMPK) that are critical for tumor induction, promotion, and progression. Based on our meta-analysis, daily grain legume consumption confers chemo-preventive effects against CRC

Low Vitamin D Status and Inadequate Nutrient Intakes of Elementary School Children in a Highly Educated Pacific Northwest Community

Are Extension healthy youth programs needed in highly educated U.S. communities? To answer this question, 175 children from four public elementary schools in Corvallis, Oregon, self-reported in a cross-sectional study their dietary intake, and 71 children provided a blood sample for measuring vitamin D concentrations. Most children had insufficient blood vitamin D and reported a diet insufficient in fiber, essential fatty acids, potassium, and vitamin E and excessive in saturated fatty acids and sodium. Our data indicate a need for Extension to provide youth programs in highly educated U.S. communities to improve nutrient intakes and vitamin D status in children

Promoting Physical Activity in Elementary Schools: Needs Assessment and a Pilot Study of Brain Breaks

A sedentary life style contributes to many chronic diseases and poor educational performance. Since elementary school-aged children spend most wakeful hours in school, classroom teachers are essential for providing physical activity (PA) breaks during school. As first objective, we assessed current PA levels for Oregon public elementary schools (379 schools responded) and learned that 92% of schools did not meet the physical education recommendation of the U.S. Centers of Disease Control and Prevention (CDC). As second objective, we evaluated teacher’s preferences for increasing students’ PA levels with a cross-sectional anonymous mail survey (116 teachers responded) and learned that teachers were concerned about students’ PA levels (84%) and interested in incorporating short PA breaks into their classroom curriculum (88%). As third objective, a follow-up survey was mailed to teachers along with the exercise DVD “Brain Breaks: Classroom Fitness for Children” that provides 5-7 minute PA segments (43 teachers responded). Teachers perceived that Brain Breaks provided students a beneficial amount of PA (86%) and improved their concentration (91%); teachers intended to continue using Brain Breaks (91%). In conclusion, short PA breaks during the school day is a promising method for promoting increased levels of PA in elementary schools. Keywords: Elementary school teachers, Physical activity, Preferences, Current statu

Regulation of Periparturient Milk Composition in Jersey Cattle

The composition of milk from dairy cows varies more in the colostral period than in other periods of lactation. The objective of this study was to determine which factors influence milk composition of Jersey cows during the colostral period. Composite milk samples were collected from 21 lactating Jersey cows of the Iowa State University Teaching Herd between February and July at 0, 12, 24, 30, 38, 46, 54, 62, 80, and 88 hours postpartum. The milk samples were analyzed for total fat, lactose, and protein content by infrared spectroscopy, for total protein nitrogen, non-casein nitrogen, and non-protein nitrogen content by Kjeldahl analyses, and for αS1–casein, β-casein, κ-casein, αS2-casein, α-lactalbumin, and β–lactoglobulin concentrations by reversed-phase HPLC. Milk composition changed during the first 4 days after parturition and was influenced by calving season, length of gestation, and parity; and all had significant interactions with time postpartum (all P \u3c 0.01). Colostrum matured to normal milk in the first two days after parturition. The maturation of colostrum was associated with an increase in lactose content and a decrease in protein content, in particular of whey proteins other than α–lactalbumin. The colostrum of cows that calved between February and April had a lower lactose and a greater protein content, in particular of whey proteins other than α–lactalbumin and β–lactoglobulin, than did colostrum of cows that calved in May and June. The colostrum of multiparous cows was higher in protein content than was the colostrum of heifers because of higher concentrations of whey proteins. During the colostral period, milk of cows that calved before the predicted calving date had greater protein concentrations than did milk from cows that calved at or after the predicted calving date, which was the result of higher concentrations of whey proteins other than α–lactalbumin and β–lactoglobulin. We conclude that time postpartum, calving season, length of gestation, and parity affect the composition of milk in the early secretory period in lactating Jersey cows

Changes in Milk Protein and Amino Acid Composition of Dairy Cows in Response to Fatty Liver and Intravenous Glucagon

Intravenous glucagon cures fatty liver by improving glucose bioavailability in early lactation. Amino acids, which would be otherwise used for milk protein synthesis, are metabolized to glucose. The objective of this study was to examine whether intravenous glucagon and fatty liver change milk protein and amino acid composition in dairy cows. Multiparous Holstein cows (n=25) were designated as either normal or susceptible to fatty liver and ketosis as based on the ratio of liver triacylglycerol to glycogen being smaller or greater than 2.0 at d 6 postpartum. Cows susceptible to fatty liver were subjected for 3 weeks to a protocol consisting of feed restriction and dietary 1,3- butanediol beginning at d 14 postpartum, which induced fatty liver and ketosis. Normal cows and cows with fatty liver were infused with glucagon for 14 d at 0 or 10 mg/d beginning at d 21 postpartum. Composite milk samples were obtained at d 20, 22, 34, and 36 postpartum and analyzed for milk protein and amino acid composition. Fatty liver decreased milk yield but had little effect on milk protein and amino acid composition except for increasing the proportion of glycosylated κ-casein. Intravenous glucagon decreased total milk protein concentrations and the proportion of α–lactalbumin and increased the proportion of glycosylated κ-casein, total κ-casein, and αS2-casein. Intravenous glucagon had little effect on milk amino acid composition. Our results suggest that milk protein and amino acid composition are under tight concomitant hormonal control and are affected little by changes in amino acid availability and/or insulin to glucagon ratio

Non-invasive Diagnosis of Fatty Liver and Degree of Fatty Liver in Dairy Cows by Digital Analyses of Hepatic Ultrasonograms

The data demonstrate that digital analyses of liver ultrasonograms could diagnose fatty liver and degree of fatty liver (healthy liver, moderate fatty liver, and severe fatty liver with their ranges of 0–8, 8–12, \u3e12% lipids of liver wet weight) with an accuracy of over 90%. Total lipid concentrations could be predicted for liver samples \u3c8% of liver wet weight within 2% of wet weight. Therefore, ultrasound imaging is a reliable, non-invasive technique for determining liver lipid content and for diagnosing fatty liver in early lactation dairy cows to prevent loss of income for dairy farmers

Improving Nutrition Education in U.S. Elementary Schools: Challenges and Opportunities

Poor food choices in childhood are core contributors to obesity and chronic diseases during adolescence and adulthood. Food choices and dietary behaviors develop in childhood and are difficult to change in adulthood. Nutrition education in elementary schools can provide children with the information and skills to develop healthy food choices and dietary behaviors. Current approaches for teaching nutrition and dietary behavior are largely ineffective to change elementary school students’ food choices. Using a cross-sectional, anonymous mail survey, we asked classroom teachers how to improve nutrition education in 17 Oregon elementary schools. Among 106 teachers who responded, most perceived that nutrition education in elementary school is very to somewhat important (97%) and can improve students’ food choices long-term (53%) or at least short-term (16%). Teachers noted multiple barriers for nutrition education, the primary being competing academic expectations (52%), lack of available time (48%), lack of suitable curricula (36%), and a food environment at school and home that does not reinforce what is taught in the classroom. Teachers preferred nutrition education that is integrated into the math, science, and/or English curriculum (54%) and includes a school cafeteria component (70%) and parent participation (53%). In conclusion, there is insufficient time and incentive to teach nutrition education as stand-alone curriculum. Renewed focus should be on developing and implementing nutrition education programs that are integrated in the math, science, and/or English curriculum and that involve and target also the food environment. Unless the food environment at school and home reinforce what is being taught in the classroom, nutrition education will have limited impact on student’s food choices. Keywords: Childhood obesity, Curriculum, Elementary school teachers, Food choices, Food Environment, Nutrition educatio

Milk Protein Genotypes Explain Variation of Milk Protein Composition

The data demonstrate that cows with the genotypes κ- casein BB and β-lactoglobulin BB produce milk with a protein composition that is favorable for increased cheese yield. For proportions of αS1-casein, κ-casein, and β-lactoglobulin in total milk protein, κ-casein and β-lactoglobulin genotypes explained more than 50 and 25% of the heritability and repeatability estimates, respectively, and more than 14% of the phenotypic variance. Diet had only a minimal effect on milk protein composition. In conclusion, increasing cheese yield through modification of milk protein composition can be achieved most rapidly by selection for cows with κ-casein BB and β-lactoglobulin BB genotypes