NA 66 Effects of sunflower oil and seed with or without fish oil on milk production
and composition in grazing dairy cows. Gagliostro, G.A., Garciarena, A.D., Oporto, M.,
Fernández, H.H., Ferlay, A. and Chilliard, Y. INTA EEA, Balcarce, Buenos Aires, Argentina. Tissu
Adipeux et Lipides du Lait, INRA-Theix, Francia. email@example.com
Efectos del aporte de aceite o semilla de girasol combinados o no con aceite de pescado sobre la
producción y composición de la leche en vacas lecheras en pastoreo
Including sunflower oil (SO) or seed (SS) as sources of linoleic acid combined or not with fish oil (FO)
in dairy cow diets may increase the healthy value of milk fat and the concentration of desirable fatty
acids (FA) like conjugated linoleic acid (CLA) and omega 3 FA. Free oils appear to be more effective
than whole oilseeds and small amounts of FO may amplify the milk CLA content. The objective of this
study was to evaluate the effects of feeding SO, SS combined or not with FO on the performance of
dairy cows. Four Holstein cows (515 ± 80 kg liveweight) in late lactation (230 DIM) fitted with
ruminal cannulae were alloted to a 4x4 Latin square design with factorial arrangement of treatments
(2x2). Each experimental period lasted 15 days. Treatments were: SS = 1.9 kg DM/cow/d; SO = 0.8
kg/cow/d; SS-FO = SS + 0.24 kg/cow/d FO and SO-FO = SO + FO. Between the morning (8.00 a.m.)
and the afternoon (16.00 p.m.) milkings the cows grazed an oat (Avena sativa, L) sward with an
herbage mass averaging 2867 kg DM/ha. Herbage allowance was adjusted at 11 kg pasture DM/cow.
After the p.m. milking the cows were supplemented with 5.6 kg DM/cow of corn silage. During each
milking time cracked corn grain (1.3 kg DM/cow) mixed with a mineral-vitamin was also offered.
Treatments that included SO were balanced for crude protein by adding 0.89 kg DM/cow of sunflower
meal to the silage. Oils and seeds were fed via ruminal cannulae to avoid refusals and SS was
coarsely ground to allow a rapid release of FA from the seed. Milk yield was recorded over the five
last days of each period and milk composition (fat, protein, lactose, milk urea and total cholesterol)
was recorded on 12th and 15th days. The model used included effects of cow, period, linoleic source,
FO supply and the interaction.Pasture, SO and FO represented 39, 5.6 and 1.6% of total DM intake
respectively (Table 1). Milk yield tended to increase in SO treatments (9,9 vs 8,7 kg/d). FCM (8,01
vs 6,37 kg/c/d) and milk fat (270 vs 191 g/d) yields increased in diets containing SO whereas milk fat
content, which was very low in all groups, was not affected (Table 2). No effects of FO supply or
interaction were detected. Concentration (40.5 vs 37.0 g/kg) and yield (397 vs 322 g/d) of milk protein
were higher in SO diets without effects of FO or their interaction. Lactose content was higher in diets
including SO (48.5 vs 45.7 g/kg) as the consequence of both, the highest concentration observed in
SO-FO and the lower value registered in SS-FO (significant AxB). Content of MUN was higher with
SS without effects of FO or their interaction. Concentration of cholesterol in milk did not differ.
Compared to SS diets, free SO alone or in combination with FO showed no detrimental effects on
production parameters of late lactation dairy cows.
Table 1: Feed composition of the experimental diets.
SS SO SS-FO SO-FO
Intake, kg DM/cow/d
Pasture 6.26 5.15 5.66 5.64
Maize silage 5.6 5.6 5.6 5.6
Corn grain 1.35 1.36 1.74 1.37
Sunflower meal 0.89 0.89
Sunflower seed 1.89 1.89
Sunflower oil 0.8 0.8
Fish oil 0.24 0.24
Total intake 15.1 13.8 15.1 15.5
Table 2: Effects of supplements on milk yield and composition.
Treatment (1) P < (2)
Item. SS SO SS-FO SO-FO SEM A B AxB
Milk, kg/cow/d 8.9 10.1 8.6 9.7 0.53 0.07 0.47 0.97
4%FCM, kg/cow/d 6.9 8.1 5.8 7.9 0.63 0.04 0.39 0.47
Fat, g/kg 25.0 24.8 19.1 27.8 2.7 0.17 0.63 0.16
Protein, g/kg 38.7 40.7 35.4 40.4 0.9 0.01 0.11 0.15
Lactose, g/kg 48.2b 47.8bc 43.2c 49.2ª 0.8 0.016 0.07 0.009
Protein/Fat 1.58 1.70 1.94 1.57 0.22 0.59 0.64 0.31
Fat, g/day 221 267 161 273 30.70 0.04 0.40 0.32
Protein, g/day 341 406 303 388 21.8 0.013 0.24 0.65
Cholesterol, mg/dl 2.88 2.44 2.46 2.41 0.16 0.18 0.22 0.27
Urea, mg/dl 2.01 1.95 2.18 1.93 0.04 0.02 0.14 0.09
Least squares means ± standar error of the mean (SEM).
Duncan's Multiple Range Test A = (SS + SS-FO) vs (SO + SO-FO); B = (SS +SO) vs (SS-FO + SO-FO).
Palabras clave: vaca lechera, aceite de girasol, semilla de girasol, aceite de pescado, pastoreo.
Key words: dairy cow, sunflower oil, sunflower seed, fish oil, grazing.