Nutritional characteristics and quality of eggs from laying hens fed on a diet supplemented with chestnut tannin extract (Castanea sativa Miller).

The trial was performed with 80 laying hens belonging to two Tuscan autochthonous breeds: 40 birds of the Mugellese (MU) breed and 40 of the White Leghorn (WL) breed. The animals were allotted to 4 groups of individually caged 20 hens each: two groups were fed on a commercial diet and worked as the control groups (MUC and WLC); the other two groups received the same diet, integrated with 2 g of chestnut tannin (CT) extract per kg of diet (MUT and WLT). A sample of 70 eggs were randomly collected and analysed for cholesterol content, fatty acid (FA) profile, weight, thickness of shell and colour of yolk. Physical parameters, including yolk colour, and indices of egg quality were not affected by the treatments. The concentration of unsaturated FAs increased, whereas cholesterol was significantly decreased: -17% in WLT and -9% in MUT. Dietary supplementation with CT extract resulted in a modification of lipid composition, towards a more healthy quality of eggs.

Effect of chestnut and quebracho tannins on fatty acid profile in rumen liquid- and solid-associated bacteria: an in vitro study.

Tannins are phenolic compounds that interfere with biohydrogenation (BH) of polyunsaturated fatty acids (FAs). The aim of the present in vitro study was to investigate the effects of two different sources of tannins on FA profiles of rumen bacteria, with particular reference to rumenic and vaccenic acid. A control diet (C; composed of 300 g/kg of wheat straw, 132 g/kg of soyabean meal, 96 g/kg of barley meal, 152 g/kg of maize meal, 300 g/kg of maize gluten and 20 g/kg of mineral vitamin premix, all expressed on dry matter (DM)) and four diets, obtained by adding to C two different types of tannins from chestnut (TC) and from quebracho (TQ) at two concentration levels (49 and 82 g/kg DM), were compared. The content of the main unsaturated FAs (C18:1 cis9, C18:1 trans11, C18:2 cis9, cis12 and C18:3 cis9, cis12, cis15) from solid-associated bacteria (SAB) and liquid-associated bacteria (LAB) was affected by the presence of tannins in the diets. In particular, C18:1 trans11 content was significantly increased, especially with TC1, whereas the decreasing of C18:1 cis9 was unaffected, regardless of the presence or the kind of tannins added to feeds. SAB contained higher amounts of intermediates of polyunsaturated FA BH (as C18:1 trans11 and C18:2 cis9, trans11) than LAB that were characterized by a higher amount of C18:0. In the concentration range adopted in this study, the effect of TC and TQ on changes of bacterial FA profile was comparable. Tannins seem to be a good means to modulate the FA profile of rumen bacteria, favouring the accumulation of C18:1 trans11 during in vitro rumen fermentation.

Effects of a dairy product (pecorino cheese) naturally rich in cis-9, trans-11 conjugated linoleic acid on lipid, inflammatory and haemorheological variables: a dietary intervention study.

BACKGROUND AND AIM: Some studies recently reported a favourable effect for cis-9, trans-11 conjugated linoleic acid (CLA) on plasma lipoprotein profile of healthy subjects. Aim of this crossover intervention study was to evaluate the influence of a short-term dietary intake of a cheese derived from sheep's milk naturally rich in CLA on several atherosclerotic biomarkers, in comparison with a commercially available cheese. METHODS AND RESULTS: Ten subjects (6 F; 4 M) with a median age of 51.5 followed for 10 weeks a diet containing 200 g/week of cheese naturally rich in CLA (intervention period) and for the same period a diet containing a commercially available cheese of the same quantity (placebo period). Consumption of the dairy product naturally rich in cis-9, trans-11 CLA determined a significant (p<0.05) reduction in inflammatory parameters such as interleukin-6 (pre: 8.08+/-1.57 vs. post: 4.58+/-0.94 pg/mL), interleukin-8 (pre: 45.02+/-5.82 vs. post: 28.59+/-2.64 pg/mL), and tumour necrosis factor-alpha (pre: 53.58+/-25.67 vs. post: 32.09+/-17.42 pg/mL) whereas no significant differences in the placebo period were observed. With regard to haemorheological parameters, the test period significantly ameliorated erythrocytes' filtration rate (pre: 7.61+/-0.71% vs. post: 9.12+/-0.97%; p=0.03) with respect to the placebo period. Moreover, a reduction in the extent of platelet aggregation, induced by arachidonic acid [pre: 87.8+/-1.76% vs. post: 77.7+/-3.56%; p=0.04] was observed during the test period in comparison with the placebo period. CONCLUSIONS: Dietary short-term intake of the tested dairy product naturally rich in cis-9, trans-11 CLA appeared to cause favourable biochemical changes of atherosclerotic markers.

Effect of butyric acid on the performance and carcass yield of broiler chickens.

Short-chain fatty acids such as butyrate are considered potential alternatives to antibiotic growth promoters. The efficacy of butyric acid on performance and carcass characteristics of broiler chickens was tested in two studies. The effect of dietary butyrate on the ability to withstand coccidial oocyte challenge also was investigated. In experiment 1, male broiler chickens were fed diets supplemented with 0 or 11 ppm virginiamycin or 0.2 or 0.4% butyric acid (as mono-, di-, and triglyceride). In experiment 2, broilers were fed bacitracin methylene disalicylate or 0.1 or 0.2% butyric acid. In another trial, birds vaccinated against coccidiosis were challenged with oocytes at 21 d and examined 6 d later. In experiment 1, diet treatments had no effect on body weight gain. Feed intake of the birds fed 0.4% butyric acid was decreased (P < 0.01) compared with birds fed the nonmedicated diet during the starter period, whereas birds fed 0.2% butyric acid had similar feed intake to the control birds. In experiment 2, diet treatments did not affect the performance of broiler chicks while carcass weight and breast meat yield increased (P < 0.01) in birds fed 0.2% butyric acid. With oocyte challenge, birds that had received butyric acid before challenge showed higher growth rate following the challenge compared with birds that received nonmedicated feed. Bacitracin decreased (P < 0.05%) duodenal villi crypt depth, whereas villus length was similar in birds fed butyric acid or the nonmedicated control diet. These results show that 0.2% butyric acid can help to maintain the performance and carcass quality of broilers, especially in vaccinated birds challenged with coccidiosis.