0
Amarula (Sclerocarya birrea A. Rich) nut cake (ANC) is a by-product that is derived from oil extraction of the dry seeds of ripe amarula fruit. Previous studies showed that ANC could be a good source of crude protein in diets for domestic animal and increases the oleic acid content in the meat of birds, which is a potential health benefit to consumers. The objectives of this study were to evaluate the effects of feeding increasing inclusion levels of ANC in diets on growth performance, nutrient digestibility and carcass characteristics of pigs. Thirty Large White × Landrace pigs were stratified by weight (20 ± 5 kg) and randomly allocated to the five experimental diets that contained: 0 (control), 50, 100, 150 and 200 g ANC/kg DM. Each pig served as a replicate unit, housed individually. The pigs were fed the experimental diets ad-libitum once in the morning, allowing a 10% of feed refusal, and had free access to water. Body weight, feed intake, average daily gain and feed conversion ratio were recorded weekly throughout the 56-day trial period. On completion of the growth trial, following a 3-day adaptation, a nutrient digestibility study was conducted over 5 days. Thereafter, pigs were fasted for 12 h, weighed, slaughtered, and carcass samples were collected for analysis.
Feed intake was not affected by dietary treatment, but average daily gains were reduced at ANC levels > 150 g/kg, resulting in poor feed conversion ratio. Protein digestibility was reduced at ANC levels > 150 g/kg, while ether extract and fibre levels increased. Warm and cold carcass weights were lower at ANC levels > 150 g/kg, with improved meat redness and lightness. The warm and cold carcass temperature and pH, dressing percentage, back fat thickness, eye muscle area, drip loss was not affected by the dietary treatments. The redness and lightness of the meat sample were improved with increased dietary inclusion of ANC, while the yellowness was not affected by the dietary treatments.
This study showed that amarula nut cake could replace soybean meal and could be used as a potential feedstuff with an inclusion level until 150 g/kg in pig diets without causing any detrimental effects on the growth performance, nutrient digestibility and carcass traits of pigs.
Mabena, P. M., Ratsaka, M. M., Nkukwana, T. T., Malebana, I. M. M., & Nkosi, B. D. (2022). Growth performance, nutrient digestibility and carcass characteristics of pigs fed diets containing amarula (Sclerocarya birrea A. Rich) nut cake as replacement to soybean meal. Tropical Animal Health and Production, 54(1), 8. http://dx.doi.org/10.21203/rs.3.rs-582720/v1
