1. Primary growth vegetative Lotus pedunculatus containing 46 and 106 g/kg dry matter (DM) of total condsnsed tannin and 3 and 14 g/kg DM of free condensed tannin, was cut and fed fresh at hourly intervals (750 g DM/d) to sheep fitted with permanent cannulas into the rumen and duodenum. Low-and high-tannin lotus contained respectively 41.3 and 31.6 g total nitrogen/kg DM and 132 and 152 g lignin/kg DM. The two forms of lotus were similar in carbohydrate composition.2. Nutrient intake was recorded and faecal output measured by direct collection. Digesta flow to the duodenum was estimated by measuring dilution at the duodenum of inert ruthenium phenanthroline (Ru-P) and chromium-EDTA markers continuously infused into the rumen.3. Effects attributable to condensed tannins were assessed by comparing the digestion of the two diets, and by comparing the digestion of each with predicted values for non-tannin-containing fresh forages fed at similar intakes. 4.Apparent digestibility of all nutrients measured was less for high-than for low-tannin lotus (P < 0.01). The levels of cellulose digested ruminally and post-ruminally in both forms of lotus were similar to predicted values. However, less hemicellulose and readily fermentable carbohydrate (RFC; soluble carbohydrate +pectin) was digested in the rumen in sheep given both forms of lotus than would be predicted for non-tannin-containing fresh forage diets, but this was compensated for by greater post-ruminal absorption of both nutrients. 5.Total N gains across the rumen (duodenal N flow -total N intake) were 1.8 and 10.5 g/d for low-and high-tannin lotus v. predicted losses of 3.7 and 2.1 g/d for non-tannin-containing fresh forages given at the same total N intakes. Post-ruminal digestion of non-amonia-N (NAN; proportion NAN flowing at duodenum) was 0.71 and 0.67 for low-and high-tannin lotus respectively v. 0.76 for comparable non-tannin-containing fresh forages. Energy absorbed as amino acids from the small intestine was calculated to be 0.29 of metabolizable energy for both forms of lotus, compared with 0.17 and 0.21 for perennial ryegrass and white clover.6 . It was concluded that the presence of condensed tannins in lotus markedly increased post-ruminal NAN absorption compared with non-tannin-containing fresh forage diets, but depressed ruminal digestion of RFC and hemicellulose.

1. Vegetative secondary growth Lotus pedunculatus was cut daily, and fed fresh at hourly intervals (600 g dry matter (DM)/d) to three groups each of three sheep fitted with permanent cannulas into the rumen and duodenum. Lotus fed to two of the groups was sprayed with low and high rates of polyethylene glycol (PEG; molecular weight 3350), which specifically binds the condensed tannins (CT). Nutrient intake and faecal excretion were measured directly, duodenal flows estimated from continuous intraruminal infusion of inert ruthenium phenanthroline (Ru-P) and CrEDTA markers, and rumen pool sizes measured at slaughter.2. Dietary concentrations of total reactive CT (i.e. that not bound to PEG) were 95,45 and 14 g/kg DM, whilst the corresponding values for free CT were 15, 5 and 2 g/kg DM.3. Increasing dietary reactive CT concentration linearly increased duodenal flows of non-ammonia nitrogen, but linearly decreased the apparent digestibility of energy and organic matter, and rumen digestion of hemicellulose but not of cellulose. Rumen digestion as a proportion of total digestion was increased by the higher PEG rate for organic matter, energy, pectin and lignin.4. High dietary CT concentration was associated with increased N retention. Rumen ammonia concentration and pool size showed only a slight decline on this diet, indicating that there must have been increased recycling of N into the rumen.5. Increasing dietary reactive CT concentration had no effect on the rate at which carbohydrate constituents were degraded in the rumen per unit time (FDR), but increased the rate at which their undegraded residues (FOR) left the rumen per unit time. The latter appeared to be the principal mechanism by which rumen digestion as a proportion of total digestion was reduced at high dietary CT concentrations. From a comparison of FDR and FOR of carbohydrate components in lotus and Brassica oleracea diets, it was concluded that hemicellulose digestion was rate-limiting for rumen cell-wall digestion, probably due to bonding with lignin. However, the considerable post-rumen digestion of hemicellulose was not associated with post-rumen lignin digestion.6. It was concluded that a desired concentration of CT in Lotus sp. should represent a balance between the positive effect of CT in improving the efficiency of N digestion and their negative effect in depressing rumen carbohydrate digestion. A recommended concentration is 3 W O g/kg DM.From measurements of duodenal non-ammonia nitrogen (NAN) flow it has been estimated that the absorption of essential amino acids was limiting the output of high producing ruminants consuming fresh forages ad lib., and this has been verified through post-rumen supplementation studies with protein (Barry 198 1, 1982; Beever & Siddons, 1986). From a review of New Zealand (NZ) literature, Barry & Reid (1986) concluded that the presence of condensed tannins (CT) uniformly distributed throughout leaf and stem tissue in forage plants would increase amino acid supply through CT reacting with plant proteins by reve...

A quantitative trait locus (QTL) was identified by linkage analysis on bovine Chromosome 19 that affects the fatty acid, myristic acid (C14:0), in subcutaneous adipose tissue of pasture-fed beef cattle (99% level: experiment-wise significance). The QTL was also shown to have significant effects on ten fatty acids in the milk fat of pasture-fed dairy cattle. A positional candidate gene for this QTL was identified as fatty acid synthase (FASN), which is a multifunctional enzyme with a central role in the metabolism of lipids. Five single nucleotide polymorphisms (SNPs) were identified in the bovine FASN gene, and animals were genotyped for FASN SNPs in three different cattle resource populations. Linkage and association mapping results using these SNPs were consistent with FASN being the gene underlying the QTL. SNP substitution effects for C14:0 percentage were found to have an effect in the opposite direction in adipose fat to that in milk fat. It is concluded that SNPs in the bovine FASN gene are associated with variation in the fatty acid composition of adipose fat and milk fat.

Interrelationships between the concentrations of total condensed tannin (TCT), free condensed tannin (FCT) and lignin were studied to gain knowledge of how to manipulate nutritive value of fresh herbages containing condensed tannins fed to ruminants. FCT was defined as condensed tannin not bound by macerates of fresh plants, with both FCT and TCT being determined with vanillin HCI. Effects of spraying lotus with polyethylene glycol (mol. wt 3350; PEG) upon the relationship between FCT and TCT was also studied. Increasing soil nutrient and climatic stress caused large and similar increases in the concentrations of TCT and of lignin. Over the range &90 g kg-' DM, 10% of TCT in Lotus sp. was detected as FCT, with increments in TCT above 90gkg-' D M being released almost entirely as FCT. PEG formed much stronger chemical bonds with condensed tannins than did plant proteins, and did not release FCT; consequently PEG application reduced the concentration of condensed tannin that was detectable with vanillin HCI. After disintegration of plant material, it is proposed that most condensed tannin is bound and co-precipitated as an insoluble complex with protein, that FCT is in equilibrium with this complex, and that bound and free tannin are indices of nutritionally beneficial and detrimental effects produced by condensed tannins in fresh forages eaten by ruminants. It was concluded that growing Lotus pedunculatus under conditions of stress leads to depressions in nutritive value through simultaneously increasing concentrations of lignin and FCT, both of which depress rumen carbohydrate digestion and voluntary intake, and that treatment with PEG offers a convenient method of separating effects due to condensed tannins from other factors influencing nutritive value.

The effects of feeding regimen on carcass characteristics, fatty acid composition and sensory quality of Musculus longissimus were studied in 16 male red deer. All animals were farm raised; eight were grazed on pasture and eight were fed a pelleted commercial feed mixture for 10 weeks prior to slaughter. The pellet-fed deer had a significantly higher dressing percentage than the pasture group. No differences were found in ultimate pH values and muscle glycogen content when comparing the treatment groups. Polar and neutral lipid fatty acid composition of the meat were analysed separately. Meat from pasture-fed deer showed a high content of the fatty acid 18:3 n-3 in the polar lipid fraction. In the same lipid fraction, the fatty acid 18:2 n-6 was dominant in meat from the pellet fed animals. Similar differences in the neutral lipid fraction were found when comparing fatty acid composition between treatment groups; however, the abundance of these fatty acids was much less. A trained expert panel using a descriptive test assessed the sensory profile of the meat. There was a significant difference between the two treatment groups for the sensory attribute of grassy flavour, with the pellet-fed animals having less grassy flavour than the animals grazing pasture. It was concluded that further research is needed to explore the effects of various feeding regimens applied to deer on parameters associated with meat lipids, including antioxidants and oxidation products.