Spss statistics base program version 22

The evaluation of MIC and MFC was carried out in triplicate and the modal value selected [20 (link)]. Experiments on the effect of natural compounds on the mycelial growth and aflatoxins (B1, B2, G1, and G2) production by A. parasiticus were performed three times using freshly prepared samples. Mean and standard deviations were calculated from all the data obtained in the experiments performed. Data were statistically evaluated by t-test (p < 0.05) to determine whether the means of two groups are equal to each other (control against treatment with essential oils or phenolic acids). All the statistical analyses were performed using the IBM SPSS Statistics Base program, version 22 (Armonk, NY, USA).

The identification and quantification of aflatoxins in the samples were performed using the software package OpenLAB CDC 2013 (Agilent Technologies, Barcelona, Spain). A sample was determined as positive when the result was above the limit of detection. A value of zero was assigned to the samples that presented aflatoxin concentration values lower than the LOD (limit of detection). For those samples that presented concentration values between LOD and LOQ, their numerical value was used.
Descriptive and comparative statistical analysis of the results were carried out using the IBM SPSS Statistics Base program, version 22 (Armonk, NY, USA). The data on aflatoxin B1 in feed and aflatoxin M1 in milk were not normally distributed after checking by Shapiro–Wilk test. Therefore, non-parametric tests were used for comparative statistics between factors. Firstly, Mann–Whitney U test was used so as to know if there were significant effects of feeding systems (unifeed vs. compound feed), season (spring vs. winter), and year (2015 vs. 2016) on aflatoxin levels in both feed and milk samples as well as in transfer ratios. Differences between the four sampling provinces in which the dairy farms were located were determined by Kruskal-Wallis test. All tests were carried out at a significance level of 0.05.