South African researchers have observed good performance results when adding leaf meal from a native African tree to finisher pig diets.
The researchers used leaf meal from Vachellia tortilis, a leguminous tree, abundant in Africa’s dry zones. Although the use of Vachellia leaves as feed sources for pigs has been reported earlier the adaptation of pigs to these diets has not been assessed. The team therefore looked at Vachellia tortilis leaf meal inclusion in the diet of finishing pigs and recorded the adaptation periods.
Vachellia tortilis – or known by its more common name umbrella thorn acacia – can be found in many places around the African continent. Photo: Wikipedia
Prolonging the adaptation phase to pig diets
In a peer-reviewed article, published in Livestock Science, researchers of the University of KwaZulu-Natal hypothesised that the amount of proanthocyanidins and fibre present in Vachellia leaf meals may prolong the adaptation phase. To further test this, a total of 48 clinically healthy male Large White × Landrace male pigs with a mean body weight of about 64 kg, aged 14 weeks were used.
In the article, the scientists describe how pigs were assigned to individual pens in a completely randomised design and allotted to each of 6 experimental diets which contained 0, 30, 60, 90, 120 and 150 g/kg dry matter of V. tortilis leaf meal. The adaptation period was measured daily while average daily feed intake (ADFI) and average daily gain (ADG) were calculated weekly with gain: feed ratio (G: F) of pigs.
The pigs’ daily feed intake dropped
Average daily feed intake decreased quadratically with increasing inclusion of V. tortilis leaf meal, the authors wrote. There was a positive linear relationship in ADG with increasing inclusion level of V. tortilis leaf meal Increasing inclusion levels of V. tortilis leaf meal displayed a quadratic increase in G: F ratio of pigs.
Inclusion levels of V. tortilis leaf meal had a linear increase on the adaptation period of pigs, according to the scientists. Inclusion level of V. tortilis leaf meal diets increases the adaptation period of pigs. As the leaf meal inclusion increased by 1 g/kg dry matter, the adaptation period increased by 0.027 days. Variation of feed intake, expressed as a coefficient of variation of feed intake, increased linearly with increasing inclusion level of V. tortilis leaf meal.
Pig performance characteristics
Performance characteristics of pigs were influenced by increasing inclusions of V. tortilis leaf meal diets, the article concluded. Increasing inclusion level of V. tortilis leaf meal diets caused a positive relationship in the adaptation period of pigs. As the leaf meal inclusion increased by 1 g/kg dry matter, the adaptation period increased by 0.027 days.
In addition, V. tortilis leaf meal inclusion also increased the variation of feed intake across the diets, according to the authors. They added that it is, however, necessary to investigate the behaviour of pigs fed on V. tortilis leaf meal inclusion and the extent of the adaptation period even in sows so that V. tortilis leaf meals can also be used in both sows and boar diets.
The published article was written by F. Thabethe, M.V. Mkwanazi, M. Khanyile and M. Chimonyo, all attached to the University of KwaZulu-Natal, Pietermaritzburg, South Africa.