Estación Experimental del Zaidín (CSIC), Profesor Albareda 1, 18008 Granada, Spain.
J Anim Sci. 2013 Feb;91(2):914-23. doi: 10.2527/jas.2012-5212. Epub 2012 Dec 12.
The effects of replacing 50% of cereals-based concentrate with feed blocks (FB) including wastes of tomato fruits (diet ACT), wastes of cucumber fruits (diet ACC), or barley grain (diet ACB) on nutrient use, ruminal fermentation, microbial N flow to the duodenum, methane emissions, and abundances of total bacteria and methanogen were studied in goats. Four adult, dry, nonpregnant, rumen-fistulated Granadina goats (32.1 ± 5.52 kg BW) were used and 4 diets were studied in 4 trials by using a 4 × 4 Latin square experimental design. Diets consisted of alfalfa hay plus concentrate in a 1:1 ratio (AC) or 1:0.5 plus FB including wastes of ACT, ACC, or ACB. In each trial, goats were randomly assigned to 1 of the diets. Intake of each FB including ACT, ACC, and ACB were 203 ± 73, 179 ± 39, and 144 ± 68 g·animal(-1)·d(-1), respectively. The ACT and ACC diets did not (P > 0.05) compromise digestible and metabolizable energy, but reduced N retention by up to 29% (P = 0.03). Cucumber-based FB decreased the purine bases (PB):N ratio (P = 0.02) in total bacterial pellets isolated from the rumen content. Tomato-based FB decreased purine derivatives urinary excretion (P = 0.04) and microbial N flow (P = 0.03) without affecting the efficiency of synthesis but decreased methane emission by 28% (P < 0.001) compared with the other diets. Tomato and cucumber-based FB resulted in greater (P < 0.001) rumen VFA concentration and molar proportions of propionate and butyrate (P ≤ 0.02) than AC and ACB diets. No effect (P = 0.07) of diet on total bacteria abundance was observed whereas the abundance of methanogens increased (P = 0.01) with wastes-based FB. Our study suggests that ACC-based FB could replace one-half of the amount of concentrate in goat diet without compromising rumen fermentation and nutrient and energy use and without increasing methane emissions. Blocks including ACT showed an antimethanogenic effect but reduced microbial N flow to the duodenum. Further research is needed to improve both N and energy use of diets including ACT- and ACC-based FB.
本研究旨在探讨以番茄废弃物（番茄果渣，ACT）、黄瓜废弃物（黄瓜果渣，ACC）或大麦谷物（ACB）替代 50%谷物浓缩饲料对山羊养分利用、瘤胃发酵、微生物氮向十二指肠的流动、甲烷排放以及总细菌和产甲烷菌丰度的影响。选用 4 只成年、干重、非妊娠、瘤胃瘘管的 Granadina 山羊（32.1 ± 5.52 kg BW），采用 4×4 拉丁方设计，进行 4 次试验，研究了 4 种饲粮。饲粮由紫花苜蓿干草和浓缩饲料以 1:1 （AC）或 1:0.5 比例组成，外加包含 ACT、ACC 或 ACB 的 FB。在每个试验中，山羊随机分配到 1 种饲粮。山羊对每种 FB 的采食量分别为 203 ± 73、179 ± 39 和 144 ± 68 g·动物(-1)·d(-1)。ACT 和 ACC 饲粮并不（P > 0.05）影响可消化和可代谢能，但降低了 29%（P = 0.03）的氮保留。基于黄瓜的 FB 降低了从瘤胃内容物中分离出的总细菌颗粒中的嘌呤碱基（PB）：N 比（P = 0.02）。基于番茄的 FB 降低了嘌呤衍生物的尿排泄（P = 0.04）和微生物氮的流动（P = 0.03），但不影响合成效率，与其他饲粮相比，甲烷排放量降低了 28%（P < 0.001）。番茄和黄瓜 FB 导致更高的（P < 0.001）瘤胃 VFA 浓度和丙酸及丁酸的摩尔比例（P ≤ 0.02），高于 AC 和 ACB 饲粮。饲粮对总细菌丰度没有影响（P = 0.07），而产甲烷菌丰度增加（P = 0.01）与基于废物的 FB 有关。本研究表明，在不影响瘤胃发酵和养分及能量利用且不增加甲烷排放的情况下，ACB 替代一半的山羊浓缩饲料是可行的。含有 ACC 的 FB 显示出抗甲烷生成作用，但降低了微生物氮向十二指肠的流动。需要进一步研究以提高含有 ACT 和 ACC 的 FB 饲粮的氮和能量利用率。
