Isolipidic additions of fat from corn germ, corn distillers grains, or corn oil in dairy cow diets.
ABSTRACT Eight multiparous and 8 primiparous Holstein cows were used in a replicated 4 x 4 Latin square design with 4-wk periods to determine the effects on dairy cow performance of feeding corn germ (CG) compared with dried distillers grains with solubles (DDGS) or corn oil (CO). Four isolipidic dietary treatments were formulated: a control diet, a 14% corn germ diet (CGD), a 30% dry distillers grains with solubles diet (DGD), and a 2.5% corn oil diet (COD). All diets were formulated to contain 6.0% fat, with the fat in the control diet provided by a ruminally inert fat source. Dry matter intake was decreased by feeding the COD compared with the CGD; however, no difference in dry matter intake was observed among the control diet, the DGD, and the COD. Dietary treatments had no effect on milk yield, energy-corrected milk, or 4% fat-corrected milk. Feeding CG had no effect on milk fat percentage when compared with the control diet; however, milk fat percentage tended to decrease with DDGS and decreased with CO when compared with the CGD. Milk protein percentage decreased when cows were fed the COD compared with the control diet. Feeding CO tended to decrease milk fat yield compared with CG; however, dietary treatments had no effect on milk protein and lactose yield. Feed efficiency was not affected by dietary treatments and averaged 1.55 kg of energy-corrected milk/kg of dry matter intake. Feeding DDGS and CO increased the concentration of vaccenic and conjugated linoleic acid in milk fat. Concentrations of monounsaturated and polyunsaturated fatty acids in milk were increased in response to feeding the 3 corn coproducts. Fat from CG appears to be relatively protected in the rumen when compared with that from DDGS and CO and therefore will not affect the production of milk fat to the degree of the more available fat in DDGS and CO.
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ABSTRACT: Sixteen multiparous cows (12 Holstein and 4 Brown Swiss, 132 +/- 20 d in milk) were used in a replicated 4 x 4 Latin square design with 4-wk periods to determine the effects of feeding corn germ on dairy cow performance. Diets were formulated with increasing concentrations of corn germ (Dakota Germ, Poet Nutrition, Sioux Falls, SD) at 0, 7, 14, and 21% of the diet dry matter (DM). All diets had a 55:45 forage to concentrate ratio, where forage was 55% corn silage and 45% alfalfa hay. Dietary fat increased from 4.8% in the control diet to 8.2% at the greatest inclusion level of corn germ. The addition of corn germ resulted in a quadratic response in DM intake with numerically greater intake at 14% of diet DM. Feeding corn germ at 7 and 14% of diet DM increased milk yield and energy-corrected milk as well as fat percentage and yield. Milk protein yield tended to decrease as the concentration of corn germ increased in the diet. Dietary treatments had no effect on feed efficiency, which averaged 1.40 kg of energy-corrected milk/kg of DMI. Increasing the dietary concentration of corn germ resulted in a linear increase in milk fat concentrations of monounsaturated and polyunsaturated fatty acids at the expense of saturated fatty acids. Milk fat concentration and yield of cis-9, trans-11 and trans-10, cis-12 conjugated linoleic acid were increased with increased dietary concentrations of corn germ. Although milk fat concentrations of both total trans-18:1 and cis-18:1 fatty acids increased linearly, a marked numeric increase in the concentration of trans-10 C18:1 was observed in milk from cows fed the 21% corn germ diet. A similar response was observed in plasma concentration of trans-10 C18:1. Feeding increasing concentrations of corn germ had no effect on plasma concentrations of glucose, triglyceride, or beta-hydroxybutyrate; however, the concentration of nonesterified fatty acids increased linearly, with plasma cholesterol concentration demonstrating a similar trend. Germ removed from corn grain before ethanol production provides an alternative source of fat for energy in lactating dairy cows when fed at 7 and 14% of diet DM. Our results suggest that fat from corn germ may be relatively protected with no adverse effect on DM intake, milk production, and milk composition when fed up to 14% of diet DM.Journal of Dairy Science 04/2009; 92(3):1023-37. · 2.57 Impact Factor
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ABSTRACT: The hypothesis that myristic acid (C14:0) has a stronger cholesterol-increasing potential than does palmitic acid is based on very few experimental observations. A randomized, strictly controlled dietary study was therefore designed to investigate the effect of a synthetic fat that was high in myristic acid, and palm oil, which is high in palmitic acid, on lipoproteins and hemostatic variables. Twelve men were served two diets (40% of energy as fat) with 41% of fat as myristic (diet M) or palmitic acid (diet P) for 3 wk with 1 mo between the two dietary schedules. Plasma HDL cholesterol was 8% higher with diet M than with diet P: 1.10 +/- 0.06 (mean +/- SEM) vs 1.01 +/- 0.05 mmol/L (P < 0.006). Diet M raised factor VII coagulant (F VIIc) activity to 98% (77-117%) vs 96% (71-109%) (medians and ranges) after diet P (P = 0.02). Total and LDL-cholesterol concentrations did not differ between the diets. In conclusion, the myristic acid test fat was not more cholesterolemic than was palm oil, but it did induce a minor rise in F VIIc activity.American Journal of Clinical Nutrition 12/1994; 60(6):919-25. · 6.50 Impact Factor
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ABSTRACT: Based on the potential benefits of cis-9, trans-11 conjugated linoleic acid (CLA) for human health, there is a need to develop effective strategies for enhancing milk fat CLA concentrations. Levels of cis-9, trans-11 CLA in milk can be increased by supplements of fish oil (FO) and sunflower oil (SO), but there is considerable variation in the response. Part of this variance may reflect time-dependent ruminal adaptations to high levels of lipid in the diet, which lead to alterations in the formation of specific biohydrogenation intermediates. To test this hypothesis, 16 late lactation Holstein-British Friesian cows were used in a repeated measures randomized block design to examine milk fatty acid composition responses to FO and SO in the diet over a 28-d period. Cows were allocated at random to corn silage-based rations (8 per treatment) containing 0 (control) or 45 g of oil supplement/kg of dry matter consisting (1:2; wt/wt) of FO and SO (FSO), and milk composition was determined on alternate days from d 1. Compared with the control, the FSO diet decreased mean dry matter intake (21.1 vs. 17.9 kg/d), milk fat (47.7 vs. 32.6 g/kg), and protein content (36.1 vs. 33.3 g/kg), but had no effect on milk yield (27.1 vs. 26.4 kg/d). Reductions in milk fat content relative to the FSO diet were associated with increases in milk trans-10 18:1, trans-10, cis-12 CLA, and trans-9, cis-11 CLA concentrations (r(2) = 0.74, 0.57, and 0.80, respectively). Compared with the control, the FSO diet reduced milk 4:0 to 18:0 and cis 18:1 content and increased trans 18:1, trans 18:2, cis-9, trans-11 CLA, 20:5 n-3, and 22:6 n-3 concentrations. The FSO diet caused a rapid elevation in milk cis-9, trans-11 CLA content, reaching a maximum of 5.37 g/100 g of fatty acids on d 5, but these increases were transient, declining to 2.35 g/100 g of fatty acids by d 15. They remained relatively constant thereafter. Even though concentrations of trans-11 18:1 followed the same pattern of temporal changes as cis-9, trans-11 CLA, the total trans 18:1 content of FSO milk was unchanged because of the concomitant increases in the concentration of other isomers (Delta(4-10) and Delta(12-15)), predominantely trans-10 18:1. In conclusion, supplementing diets with FSO enhances milk fat cis-9, trans-11 CLA content, but the high level of enrichment declines because of changes in ruminal biohydrogenation that result in trans-10 replacing trans-11 as the major 18:1 biohydrogenation intermediate formed in the rumen.Journal of Dairy Science 03/2006; 89(2):714-32. · 2.57 Impact Factor