ASSESSMENT OF CRUDE PROTEIN CONTENT IN COMMERCIAL LIVESTOCK FEEDS IN BHUTAN: A RETROSPECTIVE STUDY

Abstract

A retrospective analysis of % crude protein (% CP) content was conducted on 410 commercial concentrate feed samples (2018–2022) analyzed at the Animal Nutrition Laboratory, Bhutan. CP was determined using the Kjeldahl method and compared against Minimum Nutrient Requirement Standards (MNRS, BSAF 2025). Overall, 52.92% of samples met MNRS, while 47.08% were below standard. A Python 3 software (spicy, numpy, matplotlib) was run to test for Shapiro–Wilk (normality); Levene’s test (homogeneity); Kruskal–Wallis H test (non-parametric ANOVA equivalent); Dunn’s post-hoc test with Bonferroni correction; one-sample Wilcoxon signed-rank test with α = 0.05 throughout to assess the variation of % CP against MNRS. Kruskal–Wallis test showed significant differences among 13 feed sub-categories (H = 83.77, p < 0.001). Piggery feeds had significantly lower CP than cattle and poultry feeds (p < 0.001), while no difference existed between cattle and poultry. Dunn’s test confirmed that all significant pairwise differences involved pig feeds. Wilcoxon tests showed sow ration and pig starter were significantly below MNRS. These findings indicate systemic protein deficiency in pig feeds and highlight the need for improved feed formulation and regulatory control.