Effects of dietary sunflower seeds on lactation performance and conjugated linoleic acid content of milk

Abstract

. 2005. Effects of dietary sunflower seeds on lactation performance and conjugated linoleic acid content of milk. Can. J. Anim. Sci. 85: 75-83. The conjugated linoleic acid (CLA) concentration in milk and the lactation performance of cows fed either a control (CON) or a sunflower seed [SS; 7% of dietary dry matter (DM)] containing diet were compared in a 12-wk lactation trial, starting from week 3 after calving, with 17 multiparous and 8 primiparous cows. The CON and SS diets were isonitrogenous and provided 4 and 6% crude fat in the total mixed rations and were fed to 13 and 12 cows, respectively. Daily DM intake (DMI), milk production and weekly body weights were recorded. Milk samples collected weekly at four consecutive milkings were individually analyzed for fat, protein and lactose content, and fatty acid composition. The DMI and milk production of the cows fed the CON and SS diets were 20.5 ± 0.80 and 20.2 ± 0.80 kg d -1 (P > 0.05) and 38.2 ± 1.71 and 38.2 ± 1.71 kg d -1 (P > 0.05), respectively. No differences due to diet were observed for cow body weight, body condition score, or for content and yield of milk fat, protein and lactose. The CLA cis-9, trans-11 concentration in milk from cows fed the CON and SS diets was 3.9 and 7.9 mg g -1 fatty acids (P < 0.01), respectively. The average CLA cis-9, trans-11 yield in milk from cows fed CON and SS diets was 5.1 ± 0.07 and 10.9 ± 0.07 g d -1 , respectively, or 114% greater (P < 0.05) for cows fed the SS diet. The study indicates that sunflower seed inclusion at 7% of dietary DM to dairy cows increases the CLA concentration and yield in milk, without affecting DMI, milk production or composition. . Le poids corporel, la note d'état corporel, le rendement laitier et la teneur en lipides, en protéines et en lactose du lait ne varient pas avec le régime. La concentration d'ALC cis9, trans11 dans le lait des vaches recevant les rations CON et SS s'établissait respectivement à 3,9 et à 7,9 mg par gramme d'acides gras (P < 0,01). Le rendement moyen en ALC cis9, trans11 du lait des vaches nourries avec la ration CON ou SS se chiffrait respectivement à 5,1 ± 0,07 et à 10,9 ± 0,07 g par jour, soit 114 % de plus (P < 0,05) pour celles recevant les graines de tournesol. Les résultats indiquent que l'addition de graines de tournesol à raison de 7 % de la MS à la ration des vaches laitières accroît la concentration d'ALC et le rendement laitier sans modifier pour autant l'IMS, la production de lait et la composition de ce dernier.

Whole sunflower seeds as a source of polyunsaturated fatty acids for grazing dairy cows: Effects on metabolic profiles and resumption of postpartum ovarian cyclicity

“…The lack of a treatment effect on BCS is consistent with results reported by He et al (2005), and together with intake and milk production results, confirm that energy intake and balance were similar among the different treatments.…”

Are polycultures for silage pragmatic medleys or gallimaufries?

“…All treatments except for maize A and maize B included two genotypes or cultivars in equal proportion for each species present in the treatment. Sunflower was only considered as a small proportion of the medley based on prior work (Fisher, Bittman, Mir, Mir, & Shelford, 1993; He, Mir, Beauchemin, Ivan, & Mir, 2005) and we did not test pure stands of sunflower. Proportions of each species in mixtures were based on ideal monoculture planting densities for that species (e.g., the maize in medley was planted at density of 8 × 0.33 = 5.3 plants m –2 where 8 plants m –2 is the usual density in this location).…”