Growth, slaughter performance, abdominal visceral organ sizes, and plasma metabolic markers in indigenous, improved, and crossbred growing pigs fed roasted or sprouted cowpea (Vigna unguiculata) diets

Abstract

Growth, slaughter performance, and blood metabolic markers were evaluated in Windsnyer (W), Large White (LW) × Landrace (LR), and three-way crossbred (W × LW × LR) pigs fed control (soybean cake), sprouted, or roasted iso-nutrient, cowpea, maize-based diets. Twelve male pigs of each genotype with initial live weights of 15 ± 2.3 kg, 37 ± 1.4 kg, and 39 ± 1.2 kg (10–11% degree of maturity) were used. The pigs were on the trial diets for eight weeks in a balanced factorial experiment replicated four times. The growth rates were W × LW × LR > LW × LR > W, and control > sprouted cowpeas > roasted cowpea diets. Scaled to pig metabolic (weight 0.75), feed intake was greatest in the control, followed by sprouted cowpeas and roasted cowpeas, and pig BW was W × LW × LR ≥ LW × LR > W. The feed conversion was control < sprouted cowpeas ≤ roasted cowpea diet. Pigs on the control diet recorded the highest back fat thickness, with the least backfat in LW × LR pigs. The LW × LR pigs had more backfat on roasted than on sprouted cowpeas, whereas W pigs had more backfat on roasted cowpeas. Scaled (% live weight) liver and kidney sizes were largest in W pigs, and the kidney size was larger on roasted cowpeas. Blood marker profiles were aligned to pig growth and slaughter performance, with low total protein, albumin, and alkaline phosphatase activity in LW × LR pigs; sprouted cowpeas caused elevated plasma urea, albumin, and the alkaline phosphatase activity. The W pigs had low plasma creatinine and high cholesterol levels, with elevated cholesterol on sprouted cowpeas. The LW × LR and W × LW × LR genotypes had better growth and slaughter performance than the W pigs; cowpea was inferior to the control diet, with better efficiency on sprouted, rather than roasted, cowpeas. Pig responses to roasting or sprouting cowpeas were considered largely independent of the genotype.