Animal nutrition and lipids in animal products and their contribution to human intake and health

Few EU countries meet targets for saturated fatty acid (SFA) intake. Dairy products usually represent the single largest source of SFA, yet evidence indicates that milk has cardioprotective properties. Options for replacing some of the SFA in milk fat with cis-monounsaturated fatty acids (MUFA) through alteration of the cow’s diet are examined. Also, few people achieve minimum recommended intakes (~450–500 mg/d) of the long chain n-3 polyunsaturated fatty acids (PUFA) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Enrichment of EPA+DHA in poultry meat via bird nutrition is described and how this would impact on habitual intake is discussed.

Foods derived from animals: the impact of animal nutrition on their nutritive value and ability to sustain long-term health

Foods derived from domestic animals are a significant source of nutrients in the UK diet. However, certain aspects of some animal-derived foods, notably levels of saturated fatty acids, have given rise to concerns that these foods may contribute to the risk of cardiovascular disease, the metabolic syndrome and other conditions. However, the composition of the many animal-derived foods is not constant and can often be enhanced by manipulating the nutrition of the animal. This paper reviews these possibilities with particular attention to lipids, and draws attention to the fact that milk in particular, contains a number of compounds which may, for example, exert anti-carcinogenic effects. It is clear that the role of animal nutrition in creating foods closer to the optimum composition for long-term human health will not only be more relevant in the future, but will be vital in attempts to improve the health of the human population.

Seed survival of four tropical tree species in response to environment

The response of seed survival to storage duration and environment (temperature and moisture content) in the four tropical tree species: Cedrela odorata L., Ceiba pentandra (L.) Gaertn., Dalbergia spruceana Benth. and Tabebuia alba (Cham.) Sandwith. from Amazonia conformed to the seed viability equation of Ellis and Roberts. Estimates of the seed viability constants to calculate seed longevity in these species are provided.

Chemical composition and in vitro fermentation of tannin-rich tree fruits

Dry and mature tree fruits are a potential source of protein for goats in the semi-arid areas of southern Africa, but their chemical composition and feeding value is largely unknown. This study presents the chemical composition and in vitro fermentation of indehiscent whole fruits and separated seed and hull fractions from Acacia nilotica, Acacia erubescens, Acacia sieberiana, Acacia erioloba, Piliostigma thonningii and Dichrostachys cinerea trees. Results indicate that the N contents of whole fruits ranged between 13.5 g/kg DM (A. nilotica) and 27.1 g/kg DM (A. erubescens). Seeds had a higher N content than hulls for all tree species. A. nilotica, D. cinerea and P thonningii fruits had high levels of extractable phenolics (758, 458 and 299 g/kg DM, respectively). Soluble phenolics (SPh) and ytterbium precipitable phenolics (YbPh) levels were negatively correlated to in vitro gas production but positively correlated to in vitro organic matter degradability (iOMD). Partition factors for whole fruits at 48 h ranged between 3.6 mg/ml for A. erioloba and 7.8 mg/ml for A. nilotica. Seeds of A. erioloba, A. erubescens and P thonningii were consistently fermented more efficiently throughout the incubation period compared to their whole fruits or hulls. Estimating in vitro degradability of phenolic-rich substrates through filtration procedures can give erroneous results due to the loss of soluble phenolics, which are not necessarily degradable. The feeding value of fruits from D. cinerea and A. nilotica tree species may be reduced due to the presence of high levels of phenolics. (C) 2007 Elsevier B.V. All rights reserved.

In vitro biological activity of tannins from Acacia and other tree fruits: Correlations with colorimetric and gravimetric phenolic assays

This Study was designed to investigate impact of tannins on in vitro ruminal fermentation parameters as well as relationships between concentration and in vitro biological activity of tannins present in tree fruits. Dry and mature fruits of known phenolic content harvested from Acacia nilotica, A. erubescens, A. erioloba, A. sieberiana, Piliostigima thonningii and Dichrostachys cinerea tree species were fermented with rumen fluid in vitro with or without polyethylene glycol (PEG). Correlation between in vitro biological activity and phenolic concentration was determined. Polyethylene glycol inclusion increased Cumulative gas production from all fruit substrates. The largest Increase (225%) after 48 h incubation was observed in D. cinerea fruits while the least (12.7%) increase was observed in A. erubescens fruits. Organic matter degradability (48 h) was increased by PEG inclusion for all tree species except A. erubescens and P. thonningii. For D. cinerea fruits, colorimetric assays were poorly correlated to Increases In gas production due to PEG treatment. Ytterbium precipitable phenolics (YbPh) were also poorly correlated with response to PEG for A. erioloba and P. thonningii fruits. However, YbPh were strongly and positively correlated to the increase In Cumulative gas production due to PEG for A. erubescens and A. nilotica. Folin-Ciocalteau assayed phenolics (SPh) were not correlated to response to PEG in P. thonningii and A. sieberiana. It was Concluded that the PEG effect oil in vitro fermentation was closely related to some measures of phenolic concentration but the relationships varied with tree species.

Tanniniferous Dichrostachys cinerea fruits do not require detoxification for goat nutrition: in sacco and in vivo evaluations

This study investigated the potential of Dichrostachys cinerea fruits as a protein supplement in semi-arid areas of Zimbabwe. The tanniniferous fruits were treated with aqueous solutions of polyethylene glycol (PEG) or sodium hydroxide (NaOH). Both treatments increased the soluble fraction, rate of degradation and effective degradability (ED) of nitrogen (N) in sacco. The PEG effects were higher than the NaOH effects (e.g. a 25% vs. 6% increase in effective N degradabilities, respectively). Five treatments were evaluated in a N-balance trial using Matebele goats: ground, PEG- or NaOH-treated D. cinerea fruits, a commercial protein supplement (CPS) and no supplement. Animals offered ground fruits or CPS retained most N (3.7 or 4.1 g N/day, respectively), while those offered NaOH- or PEG-treated fruits retained significantly less N (2.7 or 1.0 g/day, respectively). Unsupplemented animals were in negative N balance (-2.4 g/day). PEG treatment deactivated the tannins more than the NaOH treatment. PEG treatment resulted in excessive protein degradation in the rumen leading to high urine N loss. It is concluded that the D. cinerea fruits were beneficial for goat N-nutrition and that the tannins did not require inactivation. D. cinerea fruits can, therefore, replace the expensive commercial protein supplement. It is also suggested that the collection and grinding of fruits could be used as a management tool to control bush encroachment. (C) 2004 Elsevier B.V. All rights reserved.

Nutrition of chicks and layers

When formulating least-cost poultry diets, ME concentration should be optimised by an iterative procedure, not entered as a fixed value. This iteration must calculate profit margins by taking into account the way in which feed intake and saleable outputs vary with ME concentration. In the case of broilers, adjustment of critical amino acid contents in direct proportion to ME concentration does not result in birds of equal fatness. To avoid an increase in fat deposition at higher energy levels, it is proposed that amino acid specifications should be adjusted in proportion to changes in the net energy supplied by the feed. A model is available which will both interpret responses to amino acids in laying trials and give economically optimal estimates of amino acid inputs for practical feed formulation. Flocks coming into lay and flocks nearing the end of the pullet year have bimodal distributions of rates of lay, with the result that calculations of requirement based on mean output will underestimate the optimal amino acid input for the flock. Chick diets containing surplus protein can lead to impaired utilisation of the first-limiting amino acid. This difficulty can be avoided by stating amino acid requirements as a proportion of the protein.

Unravelling the conundrum of tannins in animal nutrition and health

This paper examines the nutritional and veterinary effects of tannins on ruminants and makes some comparisons with non-ruminants. Tannin chemistry per se is not covered and readers are referred to several excellent reviews instead: (a) Okuda T et al. Heterocycles 30:1195-1218 (1990); (b) Ferreira D and Slade D. Nat Prod Rep 19:517-541 (2002); (c) Yoshida T et al. In Studies in Natural Product Chemistry. Elsevier Science, Amsterdam, pp. 395-453 (2000); (d) Khanbabaee K and van Ree T. Nat Prod Rep 18:641-649 (2001); (e) Okuda et al. Phytochemistvy 55:513-529 (2000). The effects of tannins on rumen micro-organisms are also not reviewed, as these have been addressed by others: (a) McSweeney CS et al. Anim Feed Sci Technol 91:83-93 (2001); (b) Smith AH and Mackie RI. Appl Environ Microbiol 70:1104-1115 (2004). This paper deals first with the nutritional effects of tannins in animal feeds, their qualitative and quantitative diversity, and the implications of tannin-protein complexation. It then summarises the known physiological and harmful effects and discusses the equivocal evidence of the bioavailability of tannins. Issues concerning tannin metabolism and systemic effects are also considered. Opportunities are presented on how to treat feeds with high tannin contents, and some lesser-known but successful feeding strategies are highlighted. Recent research has explored the use of tannins for preventing animal deaths from bloat, for reducing intestinal parasites and for lowering gaseous ammonia and methane emissions. Finally, several tannin assays and a hypothesis are discussed that merit further investigation in order to assess their suitability for predicting animal responses. The aim is to provoke discussion and spur readers into new approaches. An attempt is made to synthesise the emerging information for relating tannin structures with their activities. Although many plants with high levels of tannins produce negative effects and require treatments, others are very useful animal feeds. Our ability to predict whether tannin-containing feeds confer positive or negative effects will depend on interdisciplinary research between animal nutritionists and plant chemists. The elucidation of tannin structure-activity relationships presents exciting opportunities for future feeding strategies that will benefit ruminants and the environment within the contexts of extensive, semi-intensive and some intensive agricultural systems. (c) 2006 Society of Chemical Industry

Tannin-containing plants for animal nutrition and health

Abstract 13.12.1

Unravelling the conundrum of tannins in animal nutrition and health

This paper examines the nutritional and veterinary effects of tannins on ruminants and makes some comparisons with non-ruminants. Tannin chemistry per se is not covered and readers are referred to several excellent reviews instead: (a) Okuda T et al. Heterocycles 30:1195-1218 (1990); (b) Ferreira D and Slade D. Nat Prod Rep 19:517-541 (2002); (c) Yoshida T et al. In Studies in Natural Product Chemistry. Elsevier Science, Amsterdam, pp. 395-453 (2000); (d) Khanbabaee K and van Ree T. Nat Prod Rep 18:641-649 (2001); (e) Okuda et al. Phytochemistvy 55:513-529 (2000). The effects of tannins on rumen micro-organisms are also not reviewed, as these have been addressed by others: (a) McSweeney CS et al. Anim Feed Sci Technol 91:83-93 (2001); (b) Smith AH and Mackie RI. Appl Environ Microbiol 70:1104-1115 (2004). This paper deals first with the nutritional effects of tannins in animal feeds, their qualitative and quantitative diversity, and the implications of tannin-protein complexation. It then summarises the known physiological and harmful effects and discusses the equivocal evidence of the bioavailability of tannins. Issues concerning tannin metabolism and systemic effects are also considered. Opportunities are presented on how to treat feeds with high tannin contents, and some lesser-known but successful feeding strategies are highlighted. Recent research has explored the use of tannins for preventing animal deaths from bloat, for reducing intestinal parasites and for lowering gaseous ammonia and methane emissions. Finally, several tannin assays and a hypothesis are discussed that merit further investigation in order to assess their suitability for predicting animal responses. The aim is to provoke discussion and spur readers into new approaches. An attempt is made to synthesise the emerging information for relating tannin structures with their activities. Although many plants with high levels of tannins produce negative effects and require treatments, others are very useful animal feeds. Our ability to predict whether tannin-containing feeds confer positive or negative effects will depend on interdisciplinary research between animal nutritionists and plant chemists. The elucidation of tannin structure-activity relationships presents exciting opportunities for future feeding strategies that will benefit ruminants and the environment within the contexts of extensive, semi-intensive and some intensive agricultural systems. (c) 2006 Society of Chemical Industry

Octanol-water partition coefficients for predicting the effects of tannins in ruminant nutrition

Tannins can cause beneficial or harmful nutritional effects, but their great diversity has until now prevented a rational distinction between tannin structures and their nutritional responses. An attempt has been made to study this problem by examining the octanol-water solubilities of tannins. A relatively simple HPLC method has been developed for screening mixtures of plant tannins for their octanol-water partition coefficients (K-ow coefficients). Tannins were isolated from the fruits and leaves of different Acacia, Calliandra, Dichrostachys, and Piliostigma species, which are known to produce beneficial or harmful effects. The K-ow coefficients of these tannins ranged from 0.061 to 13.9, average coefficients of variation were 9.2% and recoveries were 107%. Acacia nilotica fruits and leaves had the highest K-ow coefficients, that is, 2.0 and 13.9, respectively. These A. nilotica products also have high concentrations of tannins. The combined effects of high octanol solubilities and high tannin concentrations may explain their negative effects on animal nutrition and health. It is known that compounds with high octanol solubilities are more easily absorbed into tissues, and it is, therefore, proposed that such compounds are more likely to cause toxicity problems especially if consumed in large quantities. According to the literature, tannins in human foods tend to have low K-ow coefficients, and this was confirmed for the tannins in Piliostigma thonningii fruits. Therefore, unconventional feeds or browse products should be screened not only for their tannin concentrations but also for low octanol-water partition coefficients in order to identify nutritionally safe feeds and to avoid potentially toxic feeds.