豆粕熱加工及酶處理提高蛋白的體外消化以及斷奶仔豬蛋白、氨基酸的消化率

發(fā)布單位:天津瑞孚農(nóng)牧科技集團(tuán)有限公司

查看次數(shù):8159

時(shí)間:2020-09-05
豆粕中含有抗?fàn)I養(yǎng)因子,限制了豬對(duì)蛋白質(zhì)的消化過程以及整體消化率。本試驗(yàn)評(píng)估了熱加工和酶處理對(duì)蛋白質(zhì)體外消化率以及斷奶仔豬蛋白、氨基酸消化率的影響。
每批豆粕(48%蛋白)分為兩部分:對(duì)照組(無深加工)和試驗(yàn)組(熱加工并酶處理的豆粕)。在體外消化試驗(yàn)中,選擇3批豆粕,每批豆粕3個(gè)重復(fù),經(jīng)過胃蛋白酶在pH 3.5下處理1.5小時(shí)(胃消化階段),然后在胰蛋白酶和膽汁提取物在pH 6.8下處理0、0.5、1、2、4、6小時(shí)(小腸消化階段)。根據(jù)豆粕在0.5、0.5-4、4小時(shí)至最后消化的部分,表示為快速消化蛋白、中速消化蛋白、慢速消化蛋白,以及未消化蛋白。試驗(yàn)選用8頭斷奶去勢公豬(大白×杜洛克,9.43±0.40kg),經(jīng)手術(shù)安置T型回腸瘺管。試驗(yàn)為尤登方設(shè)計(jì),豬只隨機(jī)分至3種日糧(無氮日糧、豆粕日糧、深加工豆粕日糧,日糧中以豆粕或深加工豆粕添加40%作為氨基酸唯一來源),日糧中添加三氧化二鉻作為指示劑。總共進(jìn)行4期試驗(yàn),每期試驗(yàn)包括5天試驗(yàn)期,2天收糞期,2天食糜收集期。速消化蛋白25%(P=0.056),減少了慢速消化蛋白48%、未消化蛋白11%(P<0.05)。動(dòng)物試驗(yàn)中,深加工提高了粗蛋白的2.3%表觀回腸消化率、2.1%標(biāo)準(zhǔn)回腸消化率(P<0.05)。深加工顯著提高了除脯氨酸、甘氨酸、半胱氨酸外其它氨基酸的表觀、標(biāo)準(zhǔn)回腸消化率,提高幅度高達(dá)3.3%。深加工對(duì)活性賴氨酸、賴氨酸:粗蛋白沒有顯著影響,但是顯著提高了賴氨酸和活性賴氨酸的標(biāo)準(zhǔn)回腸消化率3%。
總之,深加工豆粕體外消化速度和消化率顯著提高,與動(dòng)物實(shí)驗(yàn)結(jié)果相吻合,并且抗?fàn)I養(yǎng)因子含量顯著降低。因此,熱加工和酶處理可以生產(chǎn)一種更優(yōu)質(zhì)的蛋白原料,消化速度更快,消化率更高,減少了后腸道蛋白發(fā)酵的程度。

Thermomechanical and enzyme-facilitated processing of soybean meal enhanced in vitro kinetics of protein digestion and protein and amino acid digestibility in weaned pigs
Soybean meal (SBM) contains anti-nutritional factors (ANF) that may limit kinetics and total extent of protein digestion in pigs. This study evaluated the effects of thermomechanical and enzyme-facilitated (TE) processing on in vitro kinetics of crude protein (CP) digestion and CP and amino acid (AA) digestibility in weaned pigs. Each batch of SBM (48% CP) was divided into two parts: non-processed SBM as control vs. thermomechanical and enzyme-facilitated processed soybean meal (TES) as the experimental group. For digestion kinetics, samples (three batches of non-processed SBM vs. TES) were incubated in triplicate sequentially with pepsin at pH 3.5 for 1.5 h (stomach phase) and subsequently with pancreatin and bile extract at pH 6.8 for 0, 0.5, 1, 2, 4, or 6 h (small intestine phase). Protein was classified into CPfast, CPslow, and CPresistant corresponding to CP digested within the first 0.5 h, from 0.5 to 4 h, and after 4 h plus undigested CP, respectively. Eight weaned barrows (Large White × Duroc, 9.43 ± 0.40 kg) were surgically fitted with a T-cannula at the terminal ileum. Pigs were randomly assigned to a Youden square with three diets over four periods. The three diets were an N-free diet and two diets using 40% SBM or TES as the sole source of AA with Cr2O3 as an indigestible marker. Each period included sequentially a 5-d adaptation, 2-d collection of feces, and 2-d collection of ileal digesta. The TE processing reduced ANF content in TES by 91% for lectin, 22% for trypsin inhibitor activity, 75% for β-conglycinin, and 62% for glycinin compared with SBM. In vitro, TE processing increased (P < 0.05) digested CP by 5.6% and enhanced the kinetics of CP digestion by tending to increase (P = 0.056) CPfast by 25% and reducing (P < 0.05) CPslow and CPresistant by 48% and 11%, respectively. In pigs, TE processing increased (P < 0.05) apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of CP in TES by 2.3% and 2.1%, respectively. The TE processing increased (P < 0.05) AID and SID of all AA up to 3.3%, except for AID of Pro and SID of Pro, Gly, and Cys. The TE processing did not change reactive Lys or Lys:CP but increased (P < 0.05) SID of Lys and reactive Lys by 3%. Combined, the greater in vitro digestion kinetics matched the greater in vivo AID and SID of CP in TES and lower ANF compared with SBM. Thus, TE processing created a protein source that is digested faster and to a greater extent than SBM, thereby lowering the chance of protein fermentation.

文章來源:豬營養(yǎng)國際論壇
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