Scott O. Knowles

Genome-wide analysis of dietary eicosapentaenoic acid- and oleic acid-induced modulation of colon inflammation in interleukin-10 gene-deficient mice.

Background/Aims: Dietary n–3 polyunsaturated fatty acids can reduce inflammation via a range of mechanisms. This study tested the effect of dietary eicosapentaenoic acid (EPA) on intestinal inflammation using interleukin-10 gene-deficient (Il10–/–) mice. Methods: At 35 days of age, 12 weaned Il10–/– and 12 C57 mice were randomly assigned to one of two modified AIN-76A diets, supplemented with 3.7% purified ethyl esters of either EPA (n–3) or oleic acid (OA, control). To identify genes relevant to colon inflammation, transcription profiling (microarrays and qRT-PCR) and bioinformatic analyses were used. Results: In this study, dietary EPA reversed the decrease in colon fatty acid β-oxidation gene expression observed in OA-fed Il10–/– compared to C57 mice. Il10–/– mice fed the OA diet showed decreased expression of antioxidant enzyme genes, as well as those involved in detoxification of xenobiotics, compared to C57 mice on the same diet. In contrast, dietary EPA increased the expression of these genes in Il10–/– mice. Conclusions: These data indicate that dietary EPA-induced endogenous lipid oxidation which might have a potential anti-inflammatory effect on colon tissue. This is supported by the activation of the Ppara gene that regulates the expression of pro-inflammatory and immunomodulatory genes and proteins.

Molecular Characterization of the Onset and Progression of Colitis in Inoculated Interleukin-10 Gene-Deficient Mice: A Role for PPARα

The interleukin-10 gene-deficient (Il10 −/−) mouse is a model of human inflammatory bowel disease and Ppara has been identified as one of the key genes involved in regulation of colitis in the bacterially inoculated Il10 −/− model. The aims were to (1) characterize colitis onset and progression using a histopathological, transcriptomic, and proteomic approach and (2) investigate links between PPARα and IL10 using gene network analysis. Bacterial inoculation resulted in severe colitis in Il10 −/− mice from 10 to 12 weeks of age. Innate and adaptive immune responses showed differences in gene expression relating to colitis severity. Actin cytoskeleton dynamics, innate immunity, and apoptosis-linked gene and protein expression data suggested a delayed remodeling process in 12-week-old Il10 −/− mice. Gene expression changes in 12-week-old Il10 −/− mice were related to PPARα signaling likely to control colitis, but how PPARα activation might regulate intestinal IL10 production remains to be determined.

High and variable copper status identified among dairy herds in the Waikato region by concentrations of Cu in liver sourced from biopsies and cull cows

Abstract AIMS: To document the Cu supplementation practices on dairy farms in the Waikato region, determine the Cu status of those herds, and compare the suitability of liver samples sourced from biopsies and cull cows for assessing Cu status. METHODS: During spring 2008, concentrations of Cu, Mo and S were determined from pasture samples from 24 dairy farms. Feeding regimens, herd size, milksolids production, soil type, fertiliser policy and Cu supplementation practices were recorded for each property. Based on these data, 10 monitor farms were selected to represent a range of Cu intakes for herds, from 5 to 12 mg Cu/kg dry matter (DM). On each monitor farm 12 healthy lactating cows were selected for liver biopsy and collection of blood samples during the following autumn. Around the same time, livers were collected from 12 cull cows per farm when they were slaughtered, and samples of pasture were again collected from each farm. Concentrations of Cu were measured in all tissue samples. RESULTS: Concentrations of Cu in pasture tended to be higher (mean 10.4 vs 8.2 mg/kg DM) in the autumn than spring, while concentrations of Mo were lower in the autumn (mean 0.35 vs 1.07 mg/kg DM). Most of the 24 farms used Cu supplementation in some form. Mean concentrations of Cu in liver for herds ranged from 640 (SD 544) to 2,560 (SD 474) µmol/kg fresh tissue in biopsies, and 520 (SD 235) to 2,610 (SD 945) µmol/kg in liver from cull cows. Mean concentrations of Cu in serum ranged from 7.9 to 13.4 µmol/L. The variability in concentrations of Cu for each farm was greater for liver (CV 50%) than serum (CV 21%). For individual cows, concentrations of Cu in liver, obtained by biopsy, and serum were not correlated. CONCLUSIONS: The concentration of Cu in liver of dairy cows reflected widely differing dietary intakes of Cu between herds, although levels indicated an adequate Cu status on all farms in this study. Use of either biopsy samples or livers from cull cows were indicative of the Cu status of the herd. Wide variation in observed concentrations of Cu in liver indicated that at least 12 cows per herd should be sampled. On farms with intensive, long-term Cu supplementation programmes there is a risk of chronic Cu toxicity in some animals. Thus, the Cu status of dairy herds should be determined, and monitored, before making any recommendations regarding supplementation.

Trace Element Supplementation of Livestock in New Zealand: Meeting the Challenges of Free-Range Grazing Systems

Managing the mineral nutrition of free-range grazing livestock can be challenging. On farms where grazing animals are infrequently yarded, there are limited opportunities to administer trace element supplements via feeds and concentrates. In New Zealand, where the majority of sheep, cattle, and deer graze pasture year round, inadequate intake of cobalt, copper, iodine and selenium is prevalent. Scientists and farmers have developed efficient strategies to monitor and treat these dietary deficiencies. Supplementation methods suited to grazing livestock include long-acting injections, slow-release intraruminal boluses, trace element-amended fertilisers, and reticulated water supplies on dairy farms.

Adding nutritional value to meatand milk from pasture-fed livestock

Abstract Staple meat and milk provide excellent nutrition, but when traditional foods and ingredients are tailored to meet the particular nutritional or lifestyle demands of a population they become even more attractive and valuable. These foods can be considered as delivery systems for health-promoting nutrients. Nutritional improvement of meat and milk can be achieved several ways, preferably by making desirable changes on-farm to directly improve the food without subsequent manipulations. Scope for these changes is limited by animal homeostasis, but alternatives may be less desirable. Methods in vivo that suit typical pastoral farming practice and can complement the solving of animal health and production problems include: selection of traits or phenotypes; specialty diets; long-acting parenteral supplements; and modification of ruminal microflora. Successful techniques to increase the concentration of calcium, selenium, iodine and iron in milk or meat are described. Manipulations to change composition are only one part of bringing tailored foods to market. Commercial realisation of these new products needs the initiative and collaboration of scientists, veterinarians, growers and producers responding to market pull. The uptake of future biotechnologies to capture more value inside the farm gate will also be required if the pastoral industry in New Zealand is to sustain a global competitive advantage.

The effects of dietary protein intake on appendicular lean mass and muscle function in elderly men: a 10-wk randomized controlled trial

Background: The Recommended Daily Allowance (RDA) for protein intake in the adult population is widely promoted as 0.8 g · kg-1 · d-1 Aging may increase protein requirements, particularly to maintain muscle mass.Objective: We investigated whether controlled protein consumption at the current RDA or twice the RDA (2RDA) affects skeletal muscle mass and physical function in elderly men.Design: In this parallel-group randomized trial, 29 men aged >70 y [mean ± SD body mass index (in kg/m2): 28.3 ± 4.2] were provided with a complete diet containing either 0.8 (RDA) or 1.6 (2RDA) g protein · kg-1 · d-1, aimed to balance energy needs. Before treatment and after 10 wk of intervention, whole-body and appendicular lean mass were measured by using dual-energy X-ray absorptiometry. Knee-extension peak power was measured with dynamometry.Results: Both groups were found to have been in a moderate negative energy balance (mean ± SD RDA: 209 ± 213 kcal/d; 2RDA 145 ± 214 kcal/d; P= 0.427 for difference between the groups). In comparison with RDA, whole-body lean mass increased in 2RDA (P = 0.001; 1.49 ± 1.30 kg, P < 0.001 compared with -0.55 ± 1.49 kg, P = 0.149). This difference was mostly accounted for by an increase in trunk lean mass found in 2RDA (+1.39 ± 1.09 kg, P < 0.001). Appendicular lean mass also decreased in RDA compared with 2RDA (P = 0.022), driven by a reduction in RDA (-0.64 ± 0.91 kg, P = 0.005 compared with 0.11 ± 0.57 kg, P = 0.592). Adjusting for energy imbalances did not alter these findings. Knee-extension peak power was also differently affected (P = 0.012; 26.6 ± 47.7 W, P = 0.015 in 2RDA compared with -11.7 ± 31.0 W, P = 0.180 in RDA).Conclusions: Consumption of a diet providing 2RDA for protein compared with the current guidelines was found to have beneficial effects on lean body mass and leg power in elderly men. These effects were not explained by differences in energy balance. This trial was registered at the Australia New Zealand Clinical Trial Registry (www.anzctr.org.au) as ACTRN12616000310460.

Smart Foods from the pastoral sector – implications for meat and milk producers

Smart Foods, or foods with functions that confer health benefits, are the future of the food and nutrition sectors. Pastoral products such as milk and meat are easily manipulated to improve the health benefits of these products. Therefore, there is the potential for farmers to add value to their current products. Additionally, the identification of key nutrients for health and the prevention of disease using nutrigenomic and nutritional epigenetic approaches may identify new ways to manipulate milk and meat products. However, consumer perceptions of product efficacy and the marketing of foods with health claims will be drivers behind the uptake of Smart Foods in the future.

Effects of meat addition on pasta structure, nutrition and in vitro digestibility.

In our study, semolina flour was substituted with beef emulsion (EM) at three different levels of 15, 30 and 45% (w/w) to develop a pasta with enhanced nutritional profile. The protein, fat, and water content significantly increased with addition of meat. The addition of meat enhanced the pasta gluten network. The redness and yellowness of cooked pasta increased with meat addition. Tensile strength increased from 0.018N/mm(2) in the control sample to 0.046N/mm(2) in 45% beef emulsion (45EM) sample. All meat-containing samples had significantly higher elasticity than control (0.039N/mm(2)). GI significantly decreased and IVPD value increased in 45EM sample. Five essential amino acids (leucine, lysine, methionine, threonine, tryptophan) in pasta digesta increased significantly with increasing meat addition.

Lack of production response in grazing dairy cows supplemented withlong-acting injectable vitamin B12

Abstract AIM: To determine the concentrations of vitamin B12 in serum, liver and milk that identify adequate vitamin B12 status in grazing lactating cows, based on no change in milk production in response to supplementation with vitamin B12. METHODS: In October 2005, in early lactation, Friesian cows from one herd were injected S/C with 60 or 90 mg long-acting vitamin B12, or no injection (Control; n=39 per group, Day0). Pasture samples were collected for Co determination at monthly intervals over 82 days. Concentrations of vitamin B12 in milk and serum (n=10 per group) and in liver (n=5 per group) were assessed over 124 days. Milk production and composition were determined on four occasions for all cows. RESULTS: Mean concentrations of Co in pasture ranged from 0.11 to 0.34 mg/kg dry matter (DM). Mean initial concentrations of vitamin B12 in milk, serum and liver were 1,520, 128 pmol/L and 1,092 nmol/kg fresh tissue, respectively. Administration of 60 and 90 mg vitamin B12 had similar effects and increased concentrations of vitamin B12 in milk by 3-fold over controls on Day 50 (7,410 vs. 2,350 pmol/L; p<0.001) and 1.6-fold on Day 124 (3,470 vs. 2,210 pmol/L; p=0.011). Treatment with 60 and 90 mg vitamin B12 increased concentrations of vitamin B12 in serum, by at least 5-fold over controls on Day 50 (880 and 1,040 vs. 160 pmol/L; p<0.001). The two treatments increased concentrations of vitamin B12 inliver by only 1.5 fold over controls on Day 50 (1,660 and 1,900 vs. 1,200 nmol/kg fresh tissue; p<0.005). Treatment had no effect at any sampling time on daily milk volume or milk solids, fat or protein percentages. CONCLUSIONS: Concentrations of vitamin B12 in serum >128 pmol/L indicated adequate vitamin B12 status in grazing lactating cows. Supplementation with 60 or 90 mg vitamin B12 increased and maintained concentrations of vitamin B12 in serum for up to 124 days, but there was no effect on milk production. Milk was enriched in its vitamin B12 content, which would provide enhanced nutrition for calves or humans. Compared with 60 mg, the larger dose provided little additional benefit. CLINICAL RELEVANCE: Long-acting injectable vitamin B12 used to treat and prevent vitamin B12 deficiency is unlikely to improve the milk production of grazing cows when concentrations of vitamin B12 in serum are >128 pmol/L.

Dose-response effects of long-acting injectable vitamin B12 plus selenium (Se) on the vitamin B12 and Se status of ewes and their lambs

Abstract AIM: To determine the effect of increasing doses of long-acting injectable vitamin B12 plus selenium (Se) given pre-mating on the vitamin B12 and Se status of ewes and their lambs from birth to weaning. METHODS: Four groups of 24 Poll Dorset ewes each were injected 4 weeks pre-mating with different doses of a long-acting vitamin B12 + Se product, containing 3 mg vitamin B12 and 12 mg Se per ml. The treatment groups received 5 ml (15 mg vitamin B12 + 60 mg Se), 4 ml (12 mg vitamin B12 + 48 mg Se), 3 ml (9 mg vitamin B12 + 36 mg Se), or no vitamin B12 or Se (control). Twelve of the twin-bearing ewes per group were selected for the study. Efficacy of the product was evaluated from changes in the concentrations of vitamin B12 in serum and liver, and of Se in blood, liver and milk in the ewes during gestation and lactation, and in their lambs from birth to weaning. Pasture samples in paddocks grazed by the ewes and lambs were collected at about 2-monthly intervals from 200-m transects. RESULTS: The flock was Se-deficient, as the mean initial concentration of Se in the blood of ewes was 182 (SE 20.3) nmol/L. Compared with untreated controls, all doses significantly (p<0.01) increased concentrations of Se in the blood of ewes for at least 300 days. Selenium concentrations in milk were likewise increased throughout lactation, as were those in the blood and liver of lambs. The mean concentration of vitamin B12 in the serum of ewes was initially > 1,000 pmol/L, but this decreased within 28 days to <460 pmol/L. Treatment with the 5-ml and 4-ml doses raised serum vitamin B12 concentrations of ewes for at least 176 days (p<0.01), while their lambs had significantly greater concentrations of vitamin B12 in serum and liver for less than 37 days after birth. Tissue concentrations and duration of elevation of both vitamin B12 and Se were proportional to the dose administered. The mean concentrations of Se and cobalt (Co) in the pastures were 32 and 74 µg/kg dry matter (DM), respectively. CONCLUSIONS: Injecting ewes from a Se-deficient flock 4 weeks prior to mating with 48 or 60 mg Se and 12 or 15 mg vitamin B12 increased and maintained the Se status of ewes for at least 300 days, and of their lambs from birth to weaning. The vitamin B12 status of ewes was increased for at least 176 days and that of their lambs for less than 37 days. Due to the proportional nature of the response to increasing dosage, the dose rate of the formulation tested can be adjusted according to the severity of Se and Co deficiency in a flock. CLINICAL SIGNIFICANCE: A single subcutaneous injection of vitamin B12 + Se administered pre-mating to Se-deficient flocks is likely to prevent Se deficiency in ewes and their lambs until weaning, as well as increase the vitamin B12 status of ewes and their lambs until 5 weeks after lambing.