 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Milk Production with a Particular Reference to Milk Essential Fatty Acids of Lactating Cows under Grazing and Indoor Feeding Conditions) ผู้เขียน: Ratchanee Bourapa, Sayan Tudri,  ดร.จำเริญ เที่ยงธรรม, รองศาสตราจารย์ , Somchai Anusoenponpue, Soar Siwichai, ดร.สมเกียรติ ประสานพานิช, รองศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractAn experiment was conducted to study the milk quality of dairy cattle under conditions of group grazing and loose housing on high quality forage intake. Eight crossbred cows (93% Holstein and 7% Bos indicus) all in their second to fourth lactation and at 100–120 d in the mid-late period of lactation were divided equally into two groups of four cows each under a pair comparison design. The first group was allowed free grazing on pasture consisting mainly of Guinea grass using a rotational grazing procedure. The second group was kept in a shaded cow shed and fed cut-and-carried pasture from an equal-sized area of the same pasture grazed by the first group. Both groups were supplemented with Leucaena leucocephala at 3%, based on the intake requirement for body weight maintenance and milk production for the 45 d experiment. The daily milk yield was recorded throughout the experiment and weekly milk sampling was evaluated for composition. A composite sample of morning and evening milk was analyzed for the percentages of milk fat, protein and lactose, solid not fat (SNF) and essential milk fatty acids—linoleic acid (C18:2n-6; Omega 6), linolenic acid (C18:3n-3; Omega 3) and conjugated linoleic acid (CLA) contents (grams per 100 g of fat) were also analyzed. The results showed that the milk yields, the percentages of milk fat, protein and SNF, and the contents of linolenic acid (C18:3 n-3) and CLA were not significantly different between treatments. However, the lactose percentage and the content of linoleic acid (C18:2 n-6) were significantly different (P < 0.01 and P < 0.05, respectively). The outdoor grazing system significantly increased the higher milk content of linoleic acid. |