Peter Möckel

Differences in CLA isomer distribution of cow's milk lipids

The uniqueness of ruminant milk lipids is based on their high concentration of CLA. Maximal CLA concentrations in milk lipids require optimal conditions of ruminal fermentation and substrate availability, conditions like those present in pasture-fed cows. Our previous work showed that farm management (indoor feeding vs. pasture feeding) markedly influenced the CLA concentration. In this study, the objective was to evaluate the influence of the farm management system as dependent on different locations. Milk samples from different locations (Thuringia and the Alps, representing diverse altitudes) were collected during the summer months and analyzed for FA profile and CLA isomer distribution. The proportion of PUFA and total CLA in milk fat was significantly lower in milk from indoor cows compared with the pasture cows in the Alps. The trans-11 18∶1 in milk fat of Alpine cows was elevated, in contrast to lower values for trans-10 18∶1. Milk from cows grazing pasture in the Alps was higher in EPA and lower in arachidonic acid than milk from indoor-fed cows. The proportion of cis,trans/trans,cis isomers of CLA was 10 times higher from the indoor cows than from the Alpine cows. In addition to the major isomer cis-9,trans-11, this difference also occurred for the trans-11,cis-13 isomer, which represented more than a fourth of the total CLA present in milk fat. This is the first report showing a special isomer distribution in the milk fat of cows living under very natural conditions. We hypothesize that the CLA isomer trans-11,cis-13 is formed in large quantity as a result of grazing mountain pasture, which is rich in α-linolenic acid.

Influence of roughage/concentrate ratio and linseed oil on the concentration of trans-fatty acids and conjugated linoleic acid in duodenal chyme and milk fat of late lactating cows.

Abstract The objective of the study was to investigate the influence of two roughage-to-concentrate ratios, with or without linseed oil supplementation, on the flow of fatty acids in the intestinal chyme and the secretion in milk fat in late lactating cows. Seven late lactating cows fitted with cannulae in the dorsal rumen and simple T-shaped cannulae in the proximal duodenum were randomly assigned to four experimental periods applying an incomplete replicated 2×2 Latin square design. The rations consisted of meadow hay and a concentrate mixture given in a ratio of 70 : 30 or 30 : 70 on dry matter basis. The basal rations were fed without or with 200 g linseed oil daily. After three weeks of adaptation, samples from the duodenal chyme were taken to study the flow of fatty acids. Additionally, milk samples were analysed for their milk fat composition. Decreasing roughage/concentrate ratio and linseed oil supplementation significantly increased the flow of monounsaturated fatty acids (MUFA), trans-fatty acids (tFA) and conjugated linoleic acids (CLA) in the duodenum. Furthermore, linseed oil increased the flow of saturated fatty acids (SFA) in the duodenum. Higher concentrate portion (H 30) and linseed oil supplementation significantly decreased the milk fat content. SFA were lower (p < 0.05) and MUFA were higher (p < 0.05) in milk fat after linseed oil supplementation; H 30 resulted in more polyunsaturated fatty acids (PUFA, p < 0.05) in the milk. Linseed oil supplementation significantly increased tFA and CLA in milk fat. The higher CLA content in milk fat as compared to that in the digesta suggests that a substantial endogenous synthesis of CLA in the mammary gland tissue through Δ9-desaturase took place. Between 21% and 48% of duodenal t11-C18:1 were converted into c9, t11-CLA in milk fat.

Einfluß von Rapssamen in der Mastrinderernährung auf Fettsäurenmuster, Vitamin-E-Gehalt und oxidative Stabilität des Körperfettes

ZusammenfassungIn einem Einzelfütterungsversuch über 350 Tage wurden der Kraftfutter-Weizenstroh-Ration (2,5 : 1) von je 5 Mastbullen 0, 7, 14 bzw. 21 % geschrotete Rapssamen zugesetzt. Infolge des Fett- (427 g) und Vitamin-E-Gehaltes (127 mg je kg Trockensubstanz, TS) der Rapssamen stiegen der Rohfett- bzw. Vitamin-E-Gehalt der Ration von 25 über 50, 75 auf 100 g bzw. von 11 über 19, 26 auf 34 IE je kg TS an. Mit einer Endmasse von ≈ 560 kg wurden alle Tiere geschlachtet und das Fettsäurenmuster des Nieren- und Beckenhöhlenfettes und des intramuskulären Fettes im Musc. long. dorsi, der Vitamin-E-Gehalt in diesen Proben sowie im Blut und die Induktionszeit des Depotfettes mittels Rancimattest ermittelt.Der Rapssameneinsatz bewirkte sowohl im Depot- als auch im Muskelfett einen Abfall im Gehalt an C16- und einen Anstieg der C18-Fettsäuren. Das intramuskuläre Fett enthielt signifikant mehr Mono- und Polyenfettsäuren (40,2 und 7,4 %) als das Depotfett (33,5 und 2,0 %).Der Vitamin-E-Gehalt stieg mit Rapssamenzulage in allen untersuchten Tierkörperproben signifikant an, im Depotfett erhöhte er sich von 4,5 über 7,3, 8,5 auf 14,9 µg/g. Die oxidative Stabilität des Depotfettes, gemessen als Induktionszeit mittels Rancimattest, stieg nach Rapssamenzulage von 10,9 über 18,5, 16,1 auf 19,5 h an.SummaryFour groups of five fattening bulls each consumed a concentrate — wheat straw-diet (2.5 : 1) supplemented with either 0, 7, 14 or 21 % ground rape seed for 350 days. Rape seed contained 427 g crude fat (ether extract) and 127 mg vitamin E per kg dry matter. The supplementation with rapeseed increased the fat concentrations in the rations from 25 to 50, 75 and 100 g, and of vitamin E from 11 to 19, 26 and 34 mg per kg dry matter.All bulls were slaughtered with about 560 kg body weight. Fatty acid composition of depot fat and of the fat ofmusc. long. dorsi were determined by gas liquid chromatography.Vitamin E concentrations in blood, depot fat and muscle were determined by HPLC. Oxidative stability of depot fat was measured as induction time by means of rancimat-test.Rape seed supplementation decreased C16-fatty acids and increased C18-fatty acids in depot and muscle fat. Muscle fat contained significantly more mono and poly unsaturated fatty acids (40.2 and 7.4 %) than depot fat (33.5 and 2.0 %, respectively).Rape seed supplementation enhanced significantly the vitamin E-concentrations in all body samples. In depot fat vit. E increased from 4.5 to 7.3, 8.5 and 14.9 µg/g. Induction time increased from 10.9 to 18.5, 16.1 and 19.5 h, when 0, 7, 14 or 21 % rapessed were added.Four groups of five fattening bulls each consumed a concentrate--wheat straw-diet (2.5:1) supplemented with either 0, 7, 14 or 21% ground rape seed for 350 days. Rape seed contained 427 g crude fat (ether extract) and 127 mg vitamin E per kg dry matter. The supplementation with rapeseed increased the fat concentrations in the rations from 25 to 50, 75 and 100 g, and of vitamin E from 11 to 19, 26 and 34 mg per kg dry matter. All bulls were slaughtered with about 560 kg body weight. Fatty acid composition of depot fat and of the fat of musc. long. dorsi were determined by gas liquid chromatography. Vitamin E concentrations in blood, depot fat and muscle were determined by HPLC. Oxidative stability of depot fat was measured as induction time by means of rancimat-test. Rape seed supplementation decreased C16-fatty acids and increased C18-fatty acids in depot and muscle fat. Muscle fat contained significantly more mono and poly unsaturated fatty acids (40.2 and 7.4%) than depot fat (33.5 and 2.0%, respectively). Rape seed supplementation enhanced significantly the vitamin E-concentrations in all body samples. In depot fat vit. E increased from 4.5 to 7.3, 8.5 and 14.9 micrograms/g. Induction time increased from 10.9 to 18.5, 16.1 and 19.5 h, when 0, 7, 14 or 21% rapeseed were added.

Influence of Rumen Protected Fat with Methionine on the Performance of Lactating Dairy Cows

Abstract Flachowsky, G., Raasch, A, Raasch, R. and Mockel, P. 1996. Influence of rumen protected fat with methionine on the performance of lactating dairy cows. J. Appl. Anim. Res., 10: 135–148. A group feeding experiment was carried out with 248 fresh lactating dairy cows under farm conditions over 107 days. A ration consisting of maize silage, wilted grass silage and concentrate was fed to all the cows However, one group consisting of 124 cows was supplemented with 0.5 kg rumen protected fat with methionine (MAGNAPAC PLUS) per animal per day, in order to see if the protected fat with supplement with methionine could increase milk yield through higher energy intake, without any decrease in protein content of milk. Fat supplementation did not significantly influence body weight changes of cows or measured parameters of reproduction and animal health. Daily milk yield amounted to 25.1 (Control; C) and 26.3 kg (+ Fat; F). Each liter of milk contained protein 33.2 (C) and 31.9 g (+ F), fat 41.8 (C) and 42.6 ...