Performance, Biochemico-physiological and Meat Quality Responses to Dietary Mycotoxin-contaminated-Marula Seed Cake with or without Wild Garlic in Piglets

Abstract

The high cost of feed resulting from intensive pig production in developing countries highligths a crucial needs to search for inexpeensive alternatives to imported protein sources. Marula (Sclerocarya birrea caffra) seed cake (MSC) provides a noteworthy quantity of crude amino acids and protein, similar to soy bean meal (SBM) and can serve as a substitute dietary protein source for rearing piglets. However, MSC is inherently contaminated with mycotoxins due its high level of residual oil, protein content, both of which offer favourable conditions for the establishment and propagation of toxigenic fungus. Mycotoxin is known to have the potential to induce deleterious effects, thereby causing economic losses (growth retardation, oxidative stress, immunosuppression and other effects) in pigs. Therefore, strategies to counter mycotoxins’ deleterious effects in pigs fed MSC-supplemented diets are needed. This study was aimed at evaluating the effects of dietary inclusion of mycotoxin-contaminated MSC as an alternative to SBM on performance, carcass characteristics and serum biochemistry which could be ameliorated through wild garlic (Tulbhagia violacea) supplementation. A total of 48 four-week-old weaned Large White piglets were randomly allocated to four iso-caloric and iso-nitrogenous formulated diets, containing MSC substituted at 0%, 10% and 20% and 20% MSC inclusion supplemented with 2.5% wild garlic for six weeks, with each animal as an experimental unit. Thereafter, the experimental animals were sacrificed and the carcass characteristics and meat quality measurements were taken. Result showed that dietary MSC decreased body weight gain (BWG; p ≤ 0.01), feed intake (FI; P < 0.05), liver weight (P < 0.05), foreleg weights (P=0.001), Hind leg weight (p ≤ 0.05), carcass weight (P = 0.001), temperature (p ≤ 0.05), Urea (mmol/L) (p ≤ 0.05), Blood urea nitrogen/creatinine (p ≤ 0.05), Albumin/Globulin (p ≤ 0.001). Further, piglets offered 10% MSC without wild garlic had an increased (p ≤ 0.001) BWG, whereas, the inclusion of wild garlic to the (20% MSC inclusion at 2.5 wild garlic) significantly decreased (p ≤ 0.001) the overall BWG of piglets. The diet has significant effect (p ≤ 0.001) on the weekly body weight gain and weekly feed intake. There was no significant observable effect (P > 0.05) on the weekly feed conversion efficiency of weaned Large White piglets, while there were no significant effects (P > 0.05) on the weight of kidney, small intestine, large intestine, spleen, caecum and stomach. More so, the results on the biochemical indices showed that, there were significant (p ≤ 0.05) interaction effects of diet x week on the symmetric dimethylarginine, creatinine, phosphorous, calcium, alanine aminotransferase and γ-Glutamyl transferase, while there were no significant interaction effects (P > 0.05) on the glucose, urea, blood urea, total protein, albumin, globulin, albumin/globulin

ratio, alkaline phosphate, total bilirubin, cholesterol, amylase and lipase. Conclusively, this study revealed that, dietary inclusion of MSC as an alternative protein source improve growth performance, carcass characteristic and some serum biochemistry in Large White piglets. However, inclusion of marula seed cake in pig ration should not exceed 10% as higher inclusion might pose a threat to the health of the animals. Also, the inclusion of wild garlic did not appear to have any beneficial effect on the measured parameters.