Pineapple by-products have long been considered an excellent feed for ruminants. Particularly, there is a large amount of early research and experience supporting the use of pineapple wastes in beef cattle and dairy cattle (Müller, 1978). They can successfully replace a large part of (even all) the diet roughages (Müller, 1978), or part of the diet cereals in the case of meat animals (Geoffroy, 1985). Pineapple juice by-products (without the crown) were found to have a higher energy value than maize silage and were able to partly replace energy concentrates in diets for ruminants (Azevêdo et al., 2011).
However, because pineapple wastes contain low amounts of protein and minerals, supplementation is required when the diet is based on a large amount of those products in order to prevent detrimental effects on productivity and health (Müller, 1978).
Pineapple wastes are very palatable and only require a few days of adaptation (Müller, 1978). Fermented pineapple waste is less acidic than fresh waste and is preferred by livestock (Sruamsiri, 2007).
Pineapple wastes are very digestible for ruminants, with reported OM digestibility values in the 73-75% range in cattle, sheep and goats (Müller, 1978).
Early research suggests that pineapple waste could replace 30% to 90% of the forages in dairy cow rations (Müller, 1978). There are few recent publications about the use of pineapple by-products for dairy cattle. Pineapple waste mixed with rice straw replaced up to 50% roughage in the total mixed ration for dairy cattle without decreasing milk production (Sruamsiri, 2007). Using pineapple wastes in total mixed rations for dairy cows was more economically beneficial (higher milk yield and lower feed cost) than feeding pineapple wastes ad libitum with a concentrate supplement (Chinvaroj et al., 2001).
In the Philippines, fresh pineapple wastes have been extensively and successfully used to feed beef cattle, replacing up to 85% of the forage in the diet (Müller, 1978). Most trials have focused on pineapple waste silage. The value of feeding both pineapple canning by-products and pineapple crop residues (leaves and stems) was also demonstrated in the Philippines, where large scale feeding trials on cattle given pineapple pulp and pineapple leaf silage, together with a 35% protein concentrate at 0.6% body weight, gave daily live weight gains between 0.38 and 0.48 kg/d (Albarece, 1979 cited by Devendra, 1985). In the French West Indies, feeding ensiled pineapple waste (70% of the diet DM) with a protein supplement and 2.5 kg fresh forage to 250-300 kg steers resulted in high daily weight gains (1 kg/day), and allowed a marked decrease in feeding costs (Geoffroy et al., 1984). In Brazil, pineapple waste silage replaced up to 60% maize silage with no significant detrimental effect on final live weight and average daily gains, though DM, OM and ME intake decreased (Prado et al., 2003). In Vietnam, supplementation of the native grass Sacciolepis interrupta with ensiled pineapple waste resulted in higher average daily gain (0.32 vs. 0.27 kg/d). Adding rice polishings to the ensiled pineapple waste did not add nutritional benefits (Nguyen Thi Hong Nhan et al., 2009). Other ensiled mixtures have been proposed. In Malaysia, a silage made of 80% pineapple wastes and 10% poultry litter, with molasses and additives, was found to be economically viable, provided that a good nutrient balance was achieved (Müller, 1980).
In lambs, pressed (down to 24-25% DM) and ensiled pineapple waste with fresh forage and soybean meal gave similar growth (180 g/day) as the control diet (fresh forage and compound feed). It was estimated that the product had a value similar to that of pressed beet pulp (Geoffroy et al., 1984).
Several Brazilian studies have reported positively on the potential benefits of dried pineapple waste. In adult sheep, the inclusion of up to 14% dehydrated pineapple waste in Napier grass (Pennisetum purpureum) silage did not modify nutrient digestibility, but linearly increased DM intake (Ferreira et al., 2009). Dried pineapple was included at up to 27% in the diet (cottonseed meal and maize grain), replacing fresh Napier grass: the highest DM and ME intakes were observed at 11% and the authors recommended 16% as an optimal inclusion rate (Rogerio et al., 2007).
In Brazil, dehydrated pineapple by-products replaced 100% Cynodon dactylon hay in diets for growing female goats. It maintained or increased nutrient digestibility and resulted in satisfying body weight gains (Correia et al., 2006; Costa et al., 2007). In French Polynesia, ensiled pineapple by-products were found to be an interesting resource for goats during the feed shortage period in the dry season, and it was recommended to associate it with copra meal in the diet (at a level of 25% diet DM) (Llorca Lionet et al., 2000). In Nigeria, a silage made of pineapple pulp, young lima bean vines (Phaseolus lunatus) and fresh Napier grass (Pennisetum purpureum) increased dietary protein content, nutrient digestibility, nitrogen absorption and retention, and also reduced weight loss of goats during the dry season (Ajayi, 2011). In a comparison of such silages made from the vines of either lima bean, cajan pea (Cajanus cajan) or African yam bean (Sphenostylis stenocarpa), the silage based on lima bean vines, pineapple pulp and Napier grass produced the optimal growth rate and weight gain (Ajayi et al., 2012).