Use of polyethylene glycol to improve the utilisation of leguminous leaf meals in pigs: A review

Abstract

The use of leguminous leaf meal as feed ingredients for pigs needs to be intensified and improved. Leguminous trees and shrubs are valuable sources of protein, amino acids, and dietary fibre for pigs. Leguminous leaf meals are abundant in the tropical regions and their use as alternate protein-rich feed ingredients for pigs is promising. In tropics, climate change and vegetation management practices have certainly increased the availability of shrub legumes compared to grasses. There is, therefore, a need to resort on harnessing abundant and cheap feed resources to cope with environmental changes and rise of feed prices. Leguminous leaf meals are invaluable feed ingredients for pigs because of their relatively high crude protein and they are highly available. The leguminous leaves also thrive in, and tolerate, adverse climatic and soil conditions. However, their utilisation is limited by presence of polyphenolic compounds, particularly condensed tannins that inhibit their efficient use by pigs. Other challenges for the utilisation of legume-based leaf meal diets are the presence of thorns and high fibre content. If leguminous leaf meals are included in the diet beyond optimum levels, polyphenolic compounds can suppress appetite, promote feed refusal, reduce digestibility, and can induce toxicity in pigs. This warrants investigation on the use of tannin-binding agents (TBA) to improve nutrient utilisation of leguminous leaf meal-containing diets fed to pigs. The inclusion level of polyethylene glycol (PEG) in livestock diets has a huge potential to neutralise negative effects of undesirable polyphenolic compounds. Therefore, the current review aimed to assess the potential of PEG to inactivate tannin and amount of PEG to include for optimum pig performance.Keywords: Leguminous leaf meals, performance, pigs, polyethylene glycol, polyphenolic compounds

Fodder Radish as a Potential Alternative Feed Source for Livestock in South Africa

“…For example, the presence of thorns and spines on Vachellia karroo and many other browse species may cause injury to the animals or make it difficult for them to consume the foliage [19,20]. Moreover, excessive fiber content and ant-nutritive factors like tannins and toxic compounds also negatively affect feed intake, organic matter digestibility, and net energy in locally available forage resources, especially in woody species [19,21].…”

Effects of polyethylene glycol (PEG 6000) and bentonite clay incorporation in selected local browse-based diets on the performance of Small East African goats

“…During the dry season of the year, indigenous browsing species may be able to minimize feed scarcity and nutritional de ciencies (Belachew et al, 2013). Native browses have a high nutritional value, but their use as livestock feed is limited by their high amount of polyphenolics, such as tannins (Hlatini et al, 2018). Tannins are a sub-class of plant polyphenols that can precipitate proteins and form complexes (Hagerman, 2012).…”

“…Due to the extensive labor requirements and length of time required for traditional physical treatments, they do not appear to be economically viable and are less successful than chemical approaches for effectively detoxifying legume tree leaves with high tannin levels (Hlatini et al, 2018). Colloidal clays called bentonites are presently permitted for use as feed additives (binders, coagulants, and anti-caking agents) in amounts no greater than 20 g/Kg of feeding material (EFSA Panel on Additives and Products or Substances used in Animal Feed, 2010).…”

Effects of Polyethylene Glycol (PEG 6000) and Bentonite Clay Incorporation in Selected Local Browses Based Diets on the Performance of Small East African Goats

“…During the dry season of the year, indigenous browsing species may be able to minimize feed scarcity and nutritional de ciencies (Belachew et al, 2013). Native browses have a high nutritional value, but their use as livestock feed is limited by their high amount of polyphenolics, such as tannins (Hlatini et al, 2018). Tannins are a sub-class of plant polyphenols that can precipitate proteins and form complexes (Hagerman, 2012).…”