Current intakes of EPA and DHA in European populations and the potential of animal-derived foods to increase them

The beneficial effects of long-chain (C chain >= 20) n-3 PUFA are well documented and, overall, increased intake reduces risk of CVD. Recent evidence also points to a role in reducing, age-related decline in cognitive function. The two key fatty acids are EPA (20:5) and DHA (22:6), with current UK recommendation for adults being 450 mg EPA + DHA/d. Whilst some EPA and DHA can be synthesised in vivo from alpha-linolenic acid, recent data indicate this source to be very limited, Suggesting that EPA and DHA should be classified as dietary essentials. In many parts of Europe the daily intake of EPA + DHA by adults and especially young adults (18-24 years) is < 100 mg/d, since many never eat oily fish. Poultry meat contributes small but worthwhile amounts of EPA+DHA. Studies to enrich the EPA+DHA content of animal-derived foods mainly use fish oil in the diet of the animal. Recent work has shown that such enrichment has the potential to provide to the UK adult diet a daily intake of EPA+DHA of about 230 mg, with poultry meat providing the largest amount (74 mg). There are. however. concerns that the Continued and possibly increased use of fish oils in animals diets is not Sustainable and alternative approaches are being examined, including the genetic modification of certain plants to allow them to synthesise EPA and DHA from shorter-chain precursors.

Effect of replacing calcium salts of palm oil distillate with rapeseed oil, milled or whole rapeseeds on milk fatty-acid composition in cows fed maize silage-based diets

Inclusion of rapeseed feeds in dairy cow diets has the potential to reduce milk fat saturated fatty acid (SFA) and increase cis-monounsaturated fatty acid (cis-MUFA) content but effectiveness may depend on the form in which the rapeseed is presented. Four mid-lactation Holstein dairy cows were allocated to four maize silage-based dietary treatments according to a 4 x 4 Latin Square design, with 28-day experimental periods. Treatments consisted of a control diet (C containing 49 g/kg dry matter (DM) of calcium salts of palm oil distillate (CPO), or 49 g/kg DM of oil supplied as whole rapeseeds (WR), rapeseeds milled with wheat (MR) or rapeseed oil (RO). Replacing CPO with rapeseed feeds had no effect (P > 0.05) on milk fat and protein content, while milk yields were higher (P < 0.05) for RO and MR compared with WR (37.1, 38.1 and 34.3 kg/day, respectively). Substituting CPO with RO or MR reduced (P < 0.05) milk fat total SFA content (69.6, 55.6, 71.7 and 61.5 g/100g fatty acids for C, RO, WR and MR, respectively) and enhanced (P < 0.05) milk cis-9 18:1 MUFA concentrations (corresponding values 18.6, 24.3, 17.0 and 23.0 g/100g fatty acids) compared with C and WR. Treatments RO and MR also increased (P < 0.05) milk trans-MUFA content (4.4, 6.8, 10.5 g/100g fatty acids, C MR and RO, respectively). A lack of significant changes in milk fat composition when replacing CPO with WR suggests limited bioavailability of fatty acids in intact rapeseeds. In conclusion, replacing a commercial palm oil-based fat supplement in the diet with milled rapeseeds or rapeseed oil represented an effective strategy to alter milk fatty acid composition with the potential to improve human health. Inclusion of processed rapeseeds offered a good compromise for reducing milk SFA and increasing cis-MUFA, whilst minimising milk trans-MUFA and negative effects on animal performance.

Utilisation by ruminants of nitrogen compounds in silage-based diets

This paper considers the various complex changes that occur to nitrogen (N) containing compounds in forages through the processes of ensiling, rumen degradation and microbial synthesis, post-ruminal digestion and absorption and synthesis into milk protein. Particular emphasis is placed on reviewing recent data on the efficiency of utilisation of N-containing compounds in silages by rumen microbes, since low efficiency here is believed to be a major cause of large N losses to the environment on some silage-based diets. Data are reviewed which show that although rumen degradation of N compounds in silage is rapid and extensive, up to 10% of the soluble N can escape the rumen by being associated with the liquid phase. There is now firm evidence that the composition of the amino acids (AAs) absorbed is heavily dependent on the process of ensiling and that witting or use of certain silage additives conserve the initial amino acid profile of the forage. This provides an opportunity to manipulate the amino acid supply to better match demand thus potentially enhancing utilisation. This review confirms that utilisation of the N fractions in grass and legume silages in particular, is poor and the efficiency of microbial protein synthesis (EMPS) is consistently higher on maize silage-based diets. It is concluded that the way in which grass and legume silages in particular are produced and used in the future needs a radical rethink. New research needs to be aimed at enhancing the utilisation of N in the rumen through a better understanding of N/carbohydrate relationships and the ability of forages to supply degraded carbohydrate. Also more emphasis is needed on understanding of the potentially different role of the different N fractions that exist in silages. (C) 2004 Elsevier B.V. All rights reserved.

Effect of breed, gender, housing system and dietary crude protein content on performance of finishing beef cattle fed maize-silage-based diets

Maize silage-based diets with three dietary crude protein (CP) supplements were offered to 96 finishing cattle of contrasting breed (Holstein Friesian (HF) v. Simmental x HF (SHF)) and gender (bull v. steer) housed in two types of feeding system (group fed v. individually fed). The three protein supplements differed either in CP or protein degradability (degradable (LUDP) v. rumen undegradable (HUDP)) and provided CP concentrations of 142 (Con), 175 (LUDP) and 179 (HUDP) g/kg dry matter (DM) respectively, with ratios of degradable to undegradable of 3.0, 1.4 and 0.9:1 for diets Con, LOP and HUDP respectively. DM intakes were marginally higher (P = 0. 102) for LOP when compared with Con and HOP Rates of daily live-weight gain (DLWG) were higher (P = 0.005) in LUDP and HOP when compared with Con. HF had higher DM intakes than SHF although this did not result in any improvement in HF DLWG. Bulls had significantly better DM intakes, DLWG and feed conversion efficiency than steers. Conformation scores were better in SHF than HF (P < 0.001) and fat scores lower in bulls than steers (p < 0.001). There was a number of first order interactions established between dietary treatment, breed, gender and housing system with respect to rates of gain and carcass fat scores.

Effects of contrasting forage diets on phosphorus utilisation in lactating dairy cows

The effects of different forage mixtures on duodenal flow and faecal output of phosphorus (P) were measured in lactating dairy cows in two experiments. The forages comprised grass silage (GS) alone or mixtures of GS and urea-treated whole crop wheat (WCW). Replacement of GS by high levels of WCW resulted in a significant decrease in total P (TP), water-soluble P (WSP) and acid-soluble P (ASP) intakes, but increased phytate P (PP) and acid-insoluble P (AIP) intakes. Duodenal flows of all P fractions were unaffected by dietary treatments. However, the amounts of all fractions flowing to the intestine were much higher than the amounts consumed-with the exception of AIP, which was unchanged, and PP, which was considerably reduced. Diets did not significantly affect faecal outputs of TP, ASP, PP and AIP; however, faecal outputs of WSP were significantly higher on WCW than GS diets. Inclusion of WCW significantly decreased TP and WSP availabilities in the total tract but did not affect PP and AIP availabilities. A new fraction of P, which was not present in the feeds, was found in significant amounts in the intestines and proved to be soluble in dilute acid but insoluble in water. Estimated annual excretions for a herd of 100 cows ranged from 1550 to 1721 kg for total P of which 337-786 kg was WSP. The results suggest that GS based diets deposit more P in the environment. However, the potential to cause P pollution depends not only on the quantity but also on the nature of faecal P and on soil parameters. © 2004 Elsevier B.V. All rights reserved.

Evaluating the role of environmental quality in the sustainable rural economic development of England

The issue of the sustainable development of rural economies in England has recently received considerable attention. This is because many of the poorest areas in the country are rural, often of high environmental quality, but suffering from high unemployment and a lack of services and facilities. The rapid decline in agricultural incomes and in-migration of affluent urban workers since 1990 has exacerbated economic inequality in such areas. A number of factors have the potential to drive rural development and this paper applies, and considers, the feasibility of a method from the USA for combining economic and environmental variables in a regional growth model to examine the hypothesis that environmental quality is an important determinant of sustainable rural development in England. The model output suggests that, although environmental quality does play a role in sustainable rural development in England there are other, more important, factors driving development. These include business and communications infra-structure, the degree and opportunities for commuting and underlying employment prospects. The robustness and limitations of the method for combining economic and environmental variables is discussed in relation to the spatial interrelatedness of Local Authority Districts in England, and conclusions are drawn about areas for refinement and improvement of the method.

The changing structure of diets in the European Union in relation to healthy eating guidelines

Objective: Our objective in this paper is to assess diets in the European Union (EU) in relation to the recommendations of the recent World Health Organization/Food and Agriculture Organization expert consultation and to show how diets have changed between 1961 and 2001. Data and methods: Computations make use of FAOSTAT data on food availability at country level linked to a food composition database to convert foods to nutrients. We further explore the growing similarity of diets in the EU by making use of a consumption similarity index. The index provides a single number measure of dietary overlap between countries. Results: The data confirm the excessive consumption by almost all countries of saturated fats, cholesterol and sugars, and the convergence of nutrient intakes across the EU. Whereas in 1961 diets in several European countries were more similar to US diets than to those of other European countries, this is no longer the case; moreover, while EU diets have become more homogeneous, the EU as a whole and the USA have become less similar over time. Conclusions: Although the dominant cause of greater similarity in EU diets over the period studied is increased intakes in Mediterranean countries of saturated fats, cholesterol and sugar, also important are reductions in saturated fat and sugar in some Northern European countries. This suggests that healthy eating messages are finally having an impact on diets; a distinctly European diet may also be emerging.