This experiment aimed to evaluate the suitability of glycerol and propylene glycol to reduce microbial count and preserve immune properties in heat-treated goat colostrum. Colostrum samples from 11 goats were each divided into 9 aliquots. Different concentrations (2, 6, 10, and 14%; vol/vol) of either glycerol or propylene glycol were added to the aliquots. Phosphate buffer solution was added to one aliquot, which was set as the control (CG). After the respective additions, all colostrum samples were heat treated at 56°C for 1 h. After cooling, aerobic mesophilic bacteria were cultured. The samples were frozen until free fatty acid, IgG, IgA, and IgM concentrations and chitotriosidase activity were measured. No differences were found in aerobic mesophilic bacteria counts between either 10 or 14% glycerol and propylene glycol additives. These additions reduced bacterial count to a greater extent than CG, and 2 or 6% additions. Colostrum IgG concentration was not affected by either of the additives or their concentrations. The propylene glycol additive reduced IgA and IgM concentrations and chitotriosidase activity, compared with CG. Conversely, glycerol did not affect any of the studied immune variables. In conclusion, glycerol addition to goat colostrum before heat treatment is suitable to enhance bacterial reduction, whereas colostrum immune properties were not affected.

中文翻译：

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甘油和丙二醇作为添加剂在热处理过的山羊初乳中的用途。

该实验旨在评估甘油和丙二醇在热处理山羊初乳中减少微生物数量并保持免疫特性的适用性。将来自11只山羊的初乳样品各分成9等份。将不同浓度（2％，6％，10％和14％；体积/体积）的甘油或丙二醇加入等分试样中。将磷酸盐缓冲溶液添加到一份中，将其设置为对照（CG）。分别添加后，将所有初乳样品在56°C热处理1小时。冷却后，培养需氧嗜温细菌。将样品冷冻直至测量游离脂肪酸，IgG，IgA和IgM的浓度以及壳三糖苷酶的活性。有氧嗜温细菌计数在10％或14％的甘油和丙二醇添加剂之间均未发现差异。这些添加物比CG更大程度地减少了细菌数量，并且添加了2或6％。初乳IgG的浓度不受添加剂或其浓度的影响。与CG相比，丙二醇添加剂降低了IgA和IgM的浓度以及壳三糖苷酶的活性。相反，甘油不影响任何已研究的免疫变量。总之，在热处理前向山羊初乳中添加甘油适合增强细菌减少，而初乳的免疫特性没有受到影响。甘油不影响任何已研究的免疫变量。总之，在热处理前向山羊初乳中添加甘油适合增强细菌减少，而初乳的免疫特性没有受到影响。甘油不影响任何已研究的免疫变量。总之，在热处理前向山羊初乳中添加甘油适合增强细菌减少，而初乳的免疫特性没有受到影响。