Feeding Polyunsaturated Vegetable Oils to Lactating Cows

Abstract

Holstein cows fed concentrate:hay diets also were fed for 14 days supplements of soybean oil plus casein, soybean oil protected from ruminal hydrogenation by encapsulation in a casein-formaldehyde matrix, cottonseed oil plus casein, or cottonseed oil protected with casein formaldehyde. The supplements were fed at rates to give a linoleic acid (18:2) intake of 225 g/day. Yields of milk and milk protein were not affected by treatment. Milk 18:2 was not increased by the unprotected soybean oil or cottonseed oil but was increased by protected soybean and cottonseed oil from a control of 2.3 to 5.7% of total milk fat. Milk 18:0 and 18:1 also increased. Compensatory declines were observed in milk 16:0 and 14:0 acids. In fecal fatty acids during the treatment periods, percentage of 18:2 of the total fat decreased and 18:0 markedly increased. These results indicate hydrogenation of the dietary oils in the alimentary tract or a differential absorption. Fecal 16:0 and 14:0 decreased.

Effect of inclusion of protected and unprotected tallow in the supplement on the performance of lactating dairy cows

“…However, when a concentrate containing 87-5 g added tallow per kg was compared with one containing 20 g added tallow per kg, milk yield was non-significantly increased by 50 g/kg (Murphy and Gleeson, 1979a). The normally poor response to high levels of unprotected fat (Storry et al, 1974;Goering et al, 1977) may be related to the decline in digestibility, especially that of fibre, and also to a decrease in forage intake, as found in the present experiment. This theory is supported by the results of the current trial where the inclusion of 104 g unprotected tallow per kg concentrate gave a response of only 33 g/kg milk yield.…”

“…Generally the inclusion of high concentrations (up to 100 g per kg) of unprotected fat in the concentrate portion of the diet has not increased the yield of milk or milk fat (Storry, Brumby, Hall and Johnson, 1974;Goering, Wrenn, Edmondson, Weyant, Wood and Bitman, 1977;Murphy and Gleeson, 1979a). Generally the inclusion of high concentrations (up to 100 g per kg) of unprotected fat in the concentrate portion of the diet has not increased the yield of milk or milk fat (Storry, Brumby, Hall and Johnson, 1974;Goering, Wrenn, Edmondson, Weyant, Wood and Bitman, 1977;Murphy and Gleeson, 1979a).…”

Effects of nicotinamide on milk composition and production in dairy cows fed supplemental fat

“…Storry (1970Storry ( , 1973 found a decrease in the acetate : propionate ratio in the rumen. Other studies have shown little or no change in rumen VFA because of feeding unsaturated oils (Steele et al, 1971;Goering et al, 1976). Saturated FA, however, are less digestible than are unsaturated FA in the small intestine (Bayley and Lewis, 1955;Steele and Moore, 1968;.…”

“…Oils. Some studies indicate that fats, mainly unsaturated oils, depress milk fat percentage (Pan, 1972;Storry et al, 1973Storry et al, , 1974Pennington and Davis, 1975;Goering et al, 1976). Storry (1970) suggested that depression of milk fat is associated with a negative shift in the acetate:propionate ratio in the rumen.…”

“…Storry (1970) suggested that depression of milk fat is associated with a negative shift in the acetate:propionate ratio in the rumen. Some studies have shown little or no change in rumen VFA because of oil feeding (Plowman et al, 1971;Steele et al, 1971;1976); however, when protected oil that is resistant to breakdown in the rumen is fed or when oil is administered directly into the abomasum, fat depression is reversed (Plowman et al, 1971;Pan, 1972;Storry et al, 1975Storry et al, , 1974Goering et al, 1976;Yang, 1978;Kundu and Mudgal, 1985). For example, supplementation of protected safflower oil to dairy cows increased fat and protein content in milk,…”