Departamento De Producción Agraria, ETSIAAB, Universidad Politécnica De Madrid, Ciudad Universitaria , Madrid, Spain.
Arch Anim Nutr. 2020 Oct;74(5):380-396. doi: 10.1080/1745039X.2020.1756679. Epub 2020 May 14.
The effects of treating sunflower seed (SS) and meal (SM), as well as of a mixture of both feeds (SSM; 45:55) with a solution of malic acid (1 M; 400 ml/kg feed) and heating for protection against ruminal degradation were studied. Four rumen-fistulated sheep were fed two mixed diets composed of oat hay and concentrate (40:60) and differing only in the concentrate, that contained either a mixture of untreated SS and SM (control diet) or treated SS and SM (MAH diet). A crossover design with two 24-d experimental periods was used, and each period included 10 d of diet adaptation, 9 d for incubations of SS, SM and SSM, and 5 d for measuring ruminal fermentation characteristics and rumen emptying. From day 6 onwards a solution of (NH)SO was continuously infused into the rumen of each sheep to label ruminal bacteria. Feeding the MAH diet did not affect either ruminal pH or concentrations of total volatile fatty acids and NH-N, but decreased ( ≤ 0.01) the molar proportions of acetate and propionate and increased those of butyrate (p< 0.001). Organic matter and lipid contents of ruminal bacteria were lower whereas both N content and N enrichment were greater ( ≤ 0.05) in MAH-fed sheep. The effective degradability (ED) of different fractions of SS, SM and SSM were calculated from the ruminal rates of particle comminution and passage, and values were corrected for microbial contamination. The MAH treatment decreased the ED of most fractions for all feeds and increased the supply of by-pass crude protein (CP) by 19.1% and 120% for SS and SM, respectively, and that of fat by 34% for SS. The MAH treatment also increased the intestinal digestibility of the by-pass CP for both SS (from 60.1% to 75.4%) and SM (from 83.2% to 91.0%). The simultaneous heating of both feeds (SSM) reinforced the protective effect of the MAH treatment and increased the by-pass CP without altering its intestinal digestibility, increasing the intestinally digested CP content by 16.8% compared with the value estimated from the results obtained for MAH-treated SS and SM incubated independently. These results indicate that the MAH treatment was effective to protect sunflower protein against rumen degradation and increased its intestinal digestibility.
本研究旨在探讨用苹果酸（1M；400ml/kg 饲料）溶液处理以及加热处理向日葵籽（SS）和粕（SM），以及二者混合物（SSM；45:55），以防止瘤胃降解的效果。4 头瘤胃瘘管羊被喂食两种由燕麦干草和浓缩饲料（40:60）组成的混合饲料，唯一的区别在于浓缩饲料中含有未经处理的 SS 和 SM 混合物（对照饲料）或经 MAH 处理的 SS 和 SM（MAH 饲料）。采用交叉设计，进行了两个 24 天的实验期，每个实验期包括 10 天的饮食适应期，9 天用于 SS、SM 和 SSM 的孵育，以及 5 天用于测量瘤胃发酵特性和瘤胃排空。从第 6 天开始，连续向每只羊的瘤胃中注入（NH）SO 溶液，以标记瘤胃细菌。饲喂 MAH 饲料并未影响瘤胃 pH 值或总挥发性脂肪酸和 NH-N 的浓度，但降低了（≤0.01）乙酸和丙酸的摩尔比例，增加了丁酸的摩尔比例（p<0.001）。MAH 组绵羊瘤胃细菌的有机质和脂肪含量较低，但氮含量和氮富集度均较高（≤0.05）。通过测定瘤胃颗粒粉碎和通过速率，计算了 SS、SM 和 SSM 不同部分的有效降解率（ED），并对微生物污染进行了校正。MAH 处理降低了所有饲料的大多数部分的 ED，并分别使 SS 和 SM 的旁路粗蛋白（CP）供应量增加了 19.1%和 120%，使 SS 的脂肪供应量增加了 34%。MAH 处理还提高了 SS（从 60.1%到 75.4%）和 SM（从 83.2%到 91.0%）的旁路 CP 的肠道消化率。同时加热两种饲料（SSM）增强了 MAH 处理的保护作用，增加了旁路 CP，而不改变其肠道消化率，与单独孵育 MAH 处理的 SS 和 SM 所获得的结果相比，增加了 16.8%的肠道消化 CP 含量。这些结果表明，MAH 处理有效保护了向日葵蛋白免受瘤胃降解，并提高了其肠道消化率。
