有机酸(OAs)由于其调节胃肠环境的能力和其抗微生物能力而用于动物饲料中以调节胃肠疾病和腹泻。然而,关于最适当的OA及其在兔养殖中的有效性,没有足够的证据。因此,这项研究的目的是筛选和评估幼兔对六种OAs的反应,通过饮用水管理,在三个不同的浓度(pH水平)。有机酸(乙酸,ACET;甲酸,对于;丙酸,道具;乳酸,LAC;柠檬酸,CIT;和丁酸,BUT)在三种浓度(pH3、4和5)下进行了测试。还包括阴性对照(CON;非酸化水)。我们使用240只断奶兔(28日龄),分为2批。在每个批次中,将动物随机分配到19种实验治疗中的1种,并安置在每个笼子6只动物的笼子中,治疗,和批处理。在240只兔子中,包括具有6只动物的另外的笼子以确定动物的初始生理状态。在整个实验中,所有动物都用商业颗粒饲料喂养。研究的持续时间为7天,直到35天的年龄。在31和35天大的时候,在每个批次中,每天宰杀三只动物,并进行治疗。眼底消化内容物的pH值,胃窦,十二指肠,空肠,回肠,和盲肠,以及胃蛋白酶活性,是测量的。每天记录每笼的水和饲料消耗以及个体体重(BW)。OAs的种类和用量影响取水量。与CON相比,ACET3,PROP3和BUT3减少了水的摄入量,对饲料摄入量和体重增加产生负面影响。对于和CIT酸导致35天的最高体重和体重增加,与PROP相比,LAC,和BUT(p<0.05);显示ACET中间值。虽然OAs对胃和小肠pH的影响有限,与pH3相比,pH4和5的酸化水降低了回肠和盲肠的pH(p<0.05)。与pH3和pH5相比,pH4的酸化水显示出最高的(p<0.05)胃蛋白酶活性。考虑到我们筛选测试的样本量有限和短期评估期,在断奶后兔子中使用潜力最大的OAs是FOR,ACET,和pH为4的CIT。所选择的组合在幼兔中没有表现出任何早期副作用。这些结果应该在更广泛的动物群体中得到进一步证实。还建议在更长的时间内延长OAs的应用,以评估其在兔子整个生长期的作用。
Organic acids (OAs) are employed in animal feed to regulate gastrointestinal disorders and diarrhoea thanks to their ability to modulate the gastrointestinal environment and their antimicrobial capacity. However, there is not enough evidence regarding the most adequate OA and its effectiveness in rabbit farming. Therefore, the aim of this study was to screen and evaluate the response of young rabbits to six OAs, administered via drinking water, at three different concentrations (pH levels). Organic acids (acetic, ACET; formic, FOR; propionic, PROP; lactic, LAC; citric, CIT; and butyric, BUT) were tested at three concentrations (pH 3, 4, and 5). A negative control (CON; non-acidified water) was also included. We used 240 weaned rabbits (28 days old) divided into 2 batches. In each batch, animals were randomly allocated to 1 of the 19 experimental treatments and were housed in group cages of 6 animals per cage, treatment, and batch. Among the 240 rabbits, an additional cage with 6 animals was included to determine the initial physiological state of the animals. All animals were fed with commercial pelleted feed throughout the whole experiment. The duration of the study was 7 days, until 35 days of age. At 31 and 35 days of age, in each batch, three animals per day and treatment were slaughtered. The pH of the digestive contents in the fundus, antrum, duodenum, jejunum, ileum, and cecum, as well as the gastric pepsin enzyme activity, was measured. Water and feed consumption per cage and individual body weight (BW) were recorded daily. The type and dosage of OAs affected water intake. ACET 3, PROP 3, and BUT 3 reduced water intake compared to CON, negatively impacting feed intake and weight gain. FOR and CIT acids led to the highest BW and weight gain at 35 days, compared to PROP, LAC, and BUT (p < 0.05); showing ACET intermediate values. While OAs had limited effects on gastric and small intestine pH, acidified water at pH 4 and 5 lowered ileum and caecum pH (p < 0.05) compared to pH 3. Acidified water at pH 4 showed the highest (p < 0.05) pepsin activity compared to pH 3 and pH 5. Considering the limited sample size and short-term assessment period of our screening test, the OAs with the highest potential for use in post-weaning rabbits were FOR, ACET, and CIT at pH 4. The selected combinations did not exhibit any early adverse effects in young rabbits. These results should be further confirmed in a broader population of animals. It would also be advisable to extend the application of OAs over longer periods to evaluate their effects throughout the entire growing period of rabbits.