Effects of lipid supplementation on milk composition and butter properties

This study aimed to evaluate the effects of four dietary lipid supplements on milk composition and butter properties. Ten multiparous Holstein cows (64±21 days in milk) were used in a replicated 5×5 Latin square design. Cows received a basal diet without supplementation (CTL) or with 2% (dry matter basis) fatty acids (FA) provided as soybean oil (SO), calcium salts of palm FA (CS), hydrogenated tallow FA (HT) or palmitic acid-enriched supplement (PA). Treatment periods lasted 21 days, the last five days being used for sample collection. On days 18 and 19, milk from consecutive milkings was collected, pooled by treatment, and refrigerated before being transferred to the pilot plant for butter manufacture. Intake of dry matter was similar between treatments (29.5±0.6 kg/day; P = 0.14). Milk yield was increased with SO compared with CTL (+8%; P < 0.01). Milk fat concentration decreased with SO compared with any other treatment (-11 to -17%; P < 0.01) and increased with PA compared with CS (+8%; P = 0.04). Fat yield was increased by PA compared with CTL (+11%; P = 0.03). Milk true protein concentration was greater for PA and CTL compared with CS or SO (+4%; P < 0.01). Protein yield was not affected (P ≥ 0.15). At 20°C, butter made from PA milk was harder than any other treatment (P ≤ 0.01), whereas at 4°C, PA butter was only harder than CS and SO (P ≤ 0.03). At 20°C, SO butter was softer than CTL (P < 0.01).

Keywords: dairy cow, lipid supplement, butter.