- 期刊
泌乳山羊飼糧中椰子粕適當用量之探討
The proper utilization of copra meal in diets for dairy goats
摘要
為增加多樣化飼料資源的應用，在泌乳山羊飼糧中添加不同比例的椰子粕，探討對泌乳性能、羊乳脂肪酸組成、羊乳接受度與粗收入之影響，以期推薦進口椰子粕在國內泌乳山羊飼糧中的適當用量。試驗進行兩次，每次28日，每次使用20頭乳量2 kg以上之阿爾拜因及撒能乳羊，羊隻飼養於個別高架羊欄，逢機分為四組，分別餵飼含0%（對照組）、8%、16%或24%（乾基）的椰子粕飼糧，椰子粕以取代對照組飼糧中部分盤固乾草、磨碎玉米與大豆粕的方式加入，並調整各試驗飼糧的粗蛋白質與總可消化營養分濃度相近。泌乳羊飼糧添加8%到24%的椰子粕，不影響羊隻乳脂率、乳蛋白質率及乳總固形物率等乳成分，但有效降低乳中尿素氮濃度（35.4 vs. 40.0mg/dL, P＜0.05）；以中鏈脂肪酸為主的椰子粕，可以增加羊乳中鏈脂肪酸含量（≦C_(14:0), 37.2 vs. 34.0%, P＜0.05），但同時也減低了長鏈的共軛亞麻油酸與多元不飽和脂肪酸比例；乳羊飼糧中添加椰子粕可以降低影響風味的癸酸（C_(10:0)）含量，因此提升羊乳品評與接受度。椰子粕加入泌乳羊飼糧的8%到24%，會負面影響羊隻乾物質採食量、乳量及粗收入，尤其是高量添加的24%組，採食量較對照組下降16%（1.76 vs. 2.09kg/d, P＜0.05），乳量減少13%（2.59 vs. 2.97kg/d, P＜0.10）。綜合本次試驗結果顯示，椰子粕可以使用在泌乳羊隻飼糧中，其適當用量建議為飼糧乾基的16%。
並列摘要
To exploit the available feed resources and their proper utilization, imported copra meal was added into diets for lactating goats to evaluate its effect on milking performance, milk fatty acid profile, milk acceptance and crude income. Two repeated trials with 28 days each were conducted. A total of 20 head Alpine and Saanen lactating goats each trial with milk yield above 2 kg a day were used. Goats were raised in individual pens and assigned into four groups randomly. Copra meal was added into diets at 0% (control), 8%, 16% or 24% (dry matter basis) by substituting part of the corn, soybean meal and pangolagrass hay. Four diets were formulated to have similar protein and energy content. The addition of copra meal did not affect the concentrations of fat, protein and total solid of milk but effectively decreased the milk urea nitrogen (35.4 vs. 40.0 mg/dL, P ＜ 0.05). Copra meal containing major the medium chain triglycerides (MCT) increased the MCT ratio in goat milk as expected ( ≤ C_(14:0), 37.2 vs. 34.0%, P ＜ 0.05) and at the same time the ratios of long chain conjugated linoleic acids and polyunsaturated fatty acids also decreased. Capric acid (C_(10:0)) the main flavor influential factor in milk decreased following the dietary addition of copra meal. This might elucidate the reason why the copra meal groups could improve their milk panel test results and finally the acceptance. Nevertheless, dry matter intake, milk yield and crude income of goats tended to be adversely affected by the copra meal addition, especially the 24% highest group. Comparing with the control group, diet with 24% copra meal decreased goat dry matter intake by 16% (1.76 vs. 2.09 kg/d, P ＜ 0.05) and dropped milk yield by 13% (2.59 vs. 2.97 kg/d, P ＜ 0.10) , respectively. The remarkable high NDF (48.5%) and low nonstructural carbohydrate (18.9%) contents could contribute to the low performance. In summary, copra meal could be an available feedstuff for lactating goat in Taiwan. The suitable recommended ratio in diet dry matter is suggested to be 16%.