Influence of high energy supplements containing fatty acids on the productivity of pasture-fed dairy cows

1990 ◽  
Vol 30 (1) ◽  
pp. 11 ◽  
Author(s):  
KR King ◽  
CR Stockdale ◽  
TE Trigg

Three groups of 8 cows in their second month of lactation grazed irrigated perennial pasture alone, or grazed and were supplemented with either 3.3 kg/day of a high energy supplement or 3.8 kg of a high energy supplement containing additional long-chain fatty acids. Yields of milk and milk products were generally highest for those cows fed the supplement containing fat. Yield of milk fat was 13% higher in fat supplemented cows than those in the other supplemented treatment because these cows overcame the negative effect of starch supplements on milk fat test. Inclusion of long-chain fatty acids in the diet caused only minor changes in the fatty acid composition of the milk fat and in the various rumen parameters. The immediate marginal increases in daily yields of milk and milk fat per kg of long-chain fatty acids consumed by cows were 1.8 and 0.33 kg/cow. After comparison with data from other experiments, we concluded that the type of basal diet is not an important factor influencing the response of dairy cows to dietary long-chain fatty acids

1990 ◽  
Vol 41 (1) ◽  
pp. 129 ◽  
Author(s):  
KR King ◽  
CR Stockdale ◽  
TE Trigg

This experiment studied the effects of feeding a supplement of a blend of unesterified and saturated long-chain fatty acids on the productivity of dairy cows in mid-lactation. Twenty-three cows in their fourth month of lactation were individually fed ad libitum, a mixed balanced ration based on maize silage, lucerne hay and rolled grain. Varying quantities, up to 1020 g cow-1 day-1 of the fatty acid supplement, were mixed into the ration. Yields of milk and milk products were linearly related to total long-chain fatty acid intake. Milk fat content increased linearly while milk protein content averaged 3.59 (s.d. � 0.15)%. The marginal returns from feeding 1 kg of the supplement were 3.3 kg milk, 0.33 kg fat and 0.07 kg protein. The proportions of C 10:0, C12:0 and C 14:0 fatty acids in milk were decreased, while those of C 18:0 and C18:1 were increased as the result of feeding long-chain fatty acids. The concentration of lipid in plasma was increased, but acetate and D-(3)-hydroxybutyrate levels in blood remained unchanged with increased levels of dietary long-chain fatty acid. Efficiency of milk production was increased by 11% from feeding 1 kg of the supplement. In vivo digestibilities of dry matter, neutral and acid detergent fibres, and dietary long-chain fatty acids were unaffected by supplement.


1972 ◽  
Vol 23 (1) ◽  
pp. 87 ◽  
Author(s):  
JP Hogan ◽  
PJ Connell ◽  
SC Mills

Three sheep were offered lucerne hay either alone or with a supplement of safflower oil-casein particles protected from microbial digestion by treatment with formaldehyde. The supplement provided an additional 70 g of long chain fatty acids and 9 g nitrogen. It was estimated that, as a result of providing the supplement, additional nutrients derived from the small intestine included about 10 g of nitrogen and 60 g of long chain fatty acids. About 38 g of these fatty acids was absorbed in polyunsaturated form. With the basal diet, negligible amounts of polyunsaturated acids were absorbed from the small intestine. The addition of safflower oil-casein particles was associated with slight but significant increases in the flow of digesta from the abomasum but had no effect on the volume of water in the rumen or on the rates of flow from the rumen or terminal ileum. It was calculated that the supplemented diet provided, per unit of organic matter intake, about 30% more metabolizable energy, 38% more net energy, and 70% more amino acids than the basal diet.


1969 ◽  
Vol 36 (2) ◽  
pp. 169-175 ◽  
Author(s):  
Sonja Mattsson ◽  
P. Swartling ◽  
R. Nilsson

SummarySummer and winter milk-fat samples from 14 dairies in Sweden were fractionated by crystallization from acetone solution (1:8) at 15 °C. The composition of the major fatty acids of the parent milk fat and of the acetone insoluble fraction were examined by GLC, and the gross triglyceride pattern by TLC on plates of silicic acid treated with silver nitrate.The fatty acid composition of the milk fat was similar to that of milk fat from other countries and varied according to season and also, to a smaller extent, from region to region. Four fractions, representing 33–45, 41–34, 18–14 and 7–6 % of the fat and which contained progressively smaller proportions of saturated acids, were obtained by TLC.The acetone insoluble glyceride (AIG) fraction was characterized by a smaller content of short-chain fatty acids and unsaturated fatty acids, and a larger content of saturated long-chain fatty acids, than the parent milk fat. AIGs from summer milk fat contained a larger proportion of C18 acids and a smaller proportion of C6–C16 acids than AIGs from winter milk fat.Four fractions representing 62–70, 15–8, 16–15 and 7 % of the AIG fraction were obtained by TLC. The distribution of the triglycerides in the AIG fraction differed from that in the parent milk fat, mostly in the relative amounts of glycerides in the 2 most saturated TLC fractions. The seasonal variation was largely confined to these 2 fractions.


2013 ◽  
Vol 5 (3) ◽  
pp. 270-274 ◽  
Author(s):  
Anamaria COZMA ◽  
Doina MIERE ◽  
Lorena FILIP ◽  
Sanda ANDREI ◽  
Roxana BANC ◽  
...  

Milk fat and its fatty acid profile are important determinants of the technological, sensorial, and nutritional properties of milk and dairy products. The two major processes contributing to the presence of fatty acids in ruminant milk are the mammary lipogenesis and the lipid metabolism in the rumen. Among fatty acids, 4:0 to 12:0, almost all 14:0 and about a half of 16:0 in milk fat derive from de novo synthesis within the mammary gland. De novo synthesis utilizes as precursors acetate and butyrate produced through carbohydrates ruminal fermentation and involves acetyl-CoA carboxylase and fatty acid synthetase as key enzymes. The rest of 16:0 and all of the long-chain fatty acids derive from mammary uptake of circulating lipoproteins and nonesterified fatty acids that originate from digestive absorption of lipids and body fat mobilization. Further, long-chain fatty acids as well as medium-chain fatty acids entering the mammary gland can be desaturated via Δ-9 desaturase, an enzyme that acts by adding a cis-9-double bond on the fatty acid chain. Moreover, ruminal biohydrogenation of dietary unsaturated fatty acids results in the formation of numerous fatty acids available for incorporation into milk fat. Ruminal biohydrogenation is performed by rumen microbial population as a means of protection against the toxic effects of polyunsaturated fatty acids. Within the rumen microorganisms, bacteria are principally responsible for ruminal biohydrogenation when compared to protozoa and anaerobic fungi.


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