Dietary inclusion of ensiled avocado oil cake affects growth, nutrient digestion, and carcass characteristics of pigs

M.L Seshoka,A.T Kanengoni,B.D Nkosi,R.S Thomas,P.J Fourie,I.M.M Malebana

doi:10.4314/sajas.v50i6.11

Abstract

In this experiment, the effects were evaluated of various dietary inclusion levels of avocado oil cake (AOC) silage on growth performance, nutrient digestibility, and carcass characteristics in pigs. A mixture of 70% AOC, 25% wheat bran, and 5% sugarcane molasses was ensiled in 200 L drums for 90 days. It was then incorporated at 0%, 3% and 5% in the experimental diets. Twenty-seven Large White cross Landrace (LW x LR) weaner pigs, with an average live weight of 22 kg, were stratified by weight and randomly allocated to the three experimental diets (9 pigs/diet). Pigs were weighed individually each week throughout the trial. Daily feed intake, average daily gain (ADG) and feed conversion rates (FCRs) were recorded. A nutrient digestibility study was carried out on completion of the growth trial. At the end of the experiment, pigs were fasted for twelve hours and weighed to determine the final weight. The pigs were then slaughtered, and carcass samples were collected and analysed. The growth performance of pigs was not affected by diet, irrespective of fibre levels in the AOC silage. However, the addition of 3% AOC silage improved the digestibility of fibre fractions. The weights of the cold carcass, chops, and backfat thickness were reduced with AOC silage addition.

Highlights

Intensive pig production in South Africa is costly owing to the high prices of feed ingredients
Ndindana et al (2002) reported a decrease in average daily gain (ADG) and feed intake in pigs with increasing dietary inclusion levels of maize cobs, but Kanengoni et al (2014) did not observe this when maize cobs were ensiled. This means that ensiling improved the nutritive values of forages. This was consistent with the present study, since dry matter intake (DMI) and ADG in pigs were not affected by the inclusion levels of ensiled avocado oil cake (AOC)
The growth performance of pigs was not affected by inclusion of up to 5% AOC silage, irrespective of the level of fibre

Summary

Introduction

Intensive pig production in South Africa is costly owing to the high prices of feed ingredients. Feeding high fibre diets to growing pigs was often associated with increased gut fill and gastrointestinal weight, which affected the growth performance negatively and lowered the dressing percentage (Carlson et al, 1999). To sustain pig production under smallholder farmers in South Africa, the use of alternative feed resources must be considered, such as avocado (Persea Americana) oil cake (AOC), a by-product of oil extraction from avocado fruits in South Africa This by-product contains 518 g neutral detergent fibre (NDF), 393 g acid detergent fibre (ADF), 258 g acid detergent lignin (ADL), 38 g acid detergent insoluble nitrogen (ADIN) (Skenjana et al, 2006), and 119 g/kg dry matter (DM) (Nkosi et al, 2020). Avocado oil cake contains 59 mg/100 g lysine, 40 mg/100 g threonine, and 29 mg/100 g methionine, making it a poor source of amino acids (Ortega, 2003)

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