【正文】
;2 Shanghai 水嶺Qingpu Jiankang Dairy Farm, Shanghai 201703;3 China Agricultural University,Beijing 100094)Abstract: A lactation trial using 36 lactating Holstein cows was conducted to investigate the effect of partial replacement of corn grains with soybean hulls (SH) in lactating dairy cow diets on lactation performance. The treatments were control (no addition of SH) and SH replacement of corn grains in mixed concentrate at 30% level. Replacing corn grains with SH at 30% level increased kg milk yield and kg 4% fatcorrected milk yield per day (P) respectively, although the increase in milk yield was not significant (P). When corn grains were replaced with SH, there was a remarkable increase in the percentage of milk fat ( percentage。以去皮浸出工藝加工大豆的一個(gè)副產(chǎn)品是大豆皮(soyhulls)。盡管大豆皮的中性洗滌纖維(NDF)和酸性洗滌纖維(ADF)含量高達(dá)67%和50%,但其木質(zhì)素含量不足2%(NRC, 2001),這使得大豆皮的活體外干物質(zhì)消化率高達(dá)90%(孟慶翔等, 1999)。由于其能量來(lái)源是易消化纖維而不是淀粉,因此不存在玉米等淀粉類谷物抑制瘤胃纖維降解的負(fù)組合效應(yīng)(negatively associative effect)。隨著大豆皮產(chǎn)量的不斷提高,各國(guó)學(xué)者已進(jìn)行過(guò)不少研究,以期用大豆皮替代產(chǎn)奶牛淀粉類精料。Macgregor與Owen(1976)用大豆皮替代0%、27%和48%玉米的混合精料與苜蓿青貯一道飼喂奶牛,發(fā)現(xiàn)日糧處理間的產(chǎn)奶量沒(méi)有顯著差異。我國(guó)研究人員也進(jìn)行過(guò)大豆皮替代奶牛飼糧中玉米和小麥麩的研究(孟慶翔等,1999),發(fā)現(xiàn)以大豆皮替代奶牛飼糧中0、250、75和100%的玉米與小麥麩時(shí),飼糧潛在可消化組分比例和消化速度無(wú)明顯影響,但對(duì)纖維消化具有正組合效應(yīng)。 中國(guó)幅員遼闊,南北地區(qū)氣候和飼料資源供應(yīng)情況差異很大。因而,以易消化纖維含量豐富的大豆皮替代奶牛飼糧中的玉米等精料成分,對(duì)于奶牛產(chǎn)奶量和健康狀況可能具有有益的作用。1 材料與方法1.1 試驗(yàn)飼糧 根據(jù)上海地區(qū)奶牛場(chǎng)所用飼料種類情況與平均產(chǎn)奶水平,參照NRC(2001)奶牛營(yíng)養(yǎng)需要和中國(guó)奶牛飼養(yǎng)標(biāo)準(zhǔn)(日產(chǎn)奶2530 kg)配制出大豆皮替代精料中玉米(30%)的混合精料,以奶牛場(chǎng)常規(guī)飼糧作為對(duì)照飼糧(精料補(bǔ)充料配方見(jiàn)表1)。粗飼料為羊草干草1kg、鮮啤酒糟4kg、甜菜粕顆粒5kg、苜蓿干草3kg、。奶牛試驗(yàn)精料補(bǔ)充料配方 配方對(duì)照精料試驗(yàn)精料玉米45大豆皮0大麥小麥麩芝麻粕大豆粕棉籽餅棉籽DD