TITLE:
Increasing Conjugated Linoleic Acid Content in Milk and Cheese after Supplementing a Blend of Crude Soybean Oil Sediment Combined with Fish Oil to Grazing Dairy Cows
AUTHORS:
Gerardo Antonio Gagliostro, Liliana Elisabet Antonacci, Carolina Daiana Pérez, Luciana Rossetti, Martín Tassone, Verónica Frossasco, Favio Terreno, Alvaro Ugartemendia
KEYWORDS:
Oil Supplementation, Grazing Dairy Cow, Milk Fatty Acids, Conjugated Linoleic Acid, Cheese, Fish Oil, Crude Soybean Oil Sediment
JOURNAL NAME:
Open Journal of Animal Sciences,
Vol.10 No.3,
June
28,
2020
ABSTRACT: The aim of the work was to improve the healthy value of milk and cheese fatty acids (FA) by feeding a mix of crude soybean oil sediment (CSOS) combined with fish oil (FO) to grazing dairy cows. The CSOS is a by-product commonly discarded after oil extraction containing 3.3% moisture, 6% total ash and 70.7% oil, locally available, comparatively economic and easy to mix with other feed ingredients. The experiment lasted 55 days from September 30th to November 23th 2018 and was carried out at the dairy farm “Gacef” provider of milk to the dairy industrial plant “Capilla Del Se?or” (CDS) located at the Villa María City, Córdoba Province, Argentine. A herd of 80 multiparous Holstein cows producing 24 kg-1 milk·cow-1·day-1 was used. The cows grazed an alfalfa and an oat pasture that represented about 47% of total dry matter (DM) intake supplemented at 8.5 kg DM·cow-1·day-1 with a total mixed ration (TMR) composed (DM basis) by cracked corn grain (35.18%), whole plant corn silage (31.98%), pelletized soyben meal (17.99%), the CSOS supplement (13.85%) and FO (0.99%). The TMR was supplied by halves after each milking time in groupal feeders yielding 1.4 kg·cow-1·day-1 of the CSOS and 0.1 kg·cow-1·day-1 of FO. Before the start of lipid supplementation, milk samples (5) were obtained from the farm-tank representing the standar or reference milk (Ref-Milk). After 21 days of supplementary lipid supply, additional milk samples (5) were obtained representing the modified milk (Mod-Milk). Milk samples were analyzed for chemical composition and milk FA profile. At each time, sufficient quantities of both (Ref- and Mod-Milk) were collected for manufacturing six types of cheeses. The results were analyzed through the Student-T test for independent observations. Oil supplementation did not modify (P > 0.05) the chemical composition of milk. Concentration of butyric acid (C4:0) in milk was not affected (P -1 FA and was decreased to 49.67 g 100 g-1 FA in Mod-Milk (P -1 FA in Ref-Milk to 38.13 g 100 g-1 FA in Mod-Milk (+19.07%) whereas polyunsaturated FA (PUFAs) increased (+36.1%) from 4.71 to 6.41 (P -1 FA) for the total concentration of the potentially atherogenic fraction of milk FA (C12:0 to C16:0). The atherogenic index (AI) also decreased (P trans-11 C18:1) in Mod-Milk averaged 7.77 g 100 g-1 FA which represented a 162 % increase (P -1). Concentration of conjugated linoleic acid (CLA, cis-9, trans-11 C18:2) in Ref-Milk averaged 1.47 g 100 g-1 FA and showed an important increase (P -1 FA, +163%). The omega 6/3 ratio resulted lower (P