Pineapple Wastes 3: Use of leaves, stem, and crown as animal feed
Published Date: 21st September 2020
The non-fruit wastes generated from pineapple production, which also constitute the field wastes are the leaves, stem, and crowns. Pineapple leaf and stem wastes are generated during pruning, and replanting activities at farm sites. Usually, the wastes are discarded and left at the farm sites until they decompose naturally, or are burnt to make space for replanting. The pineapple plant has strong, rough, horizontal leaves that are tapered from base to tip. They are spirally arranged in a Fibonacci series around the stem of the fruit, thus ensuring maximum exposure of leaves under sunlight. In good health, the cross-section of the leaf reveals an almost 4-mm-thick water storage area with an adequate water reservoir that acts as a catalyst to plant growth, fruit nutrients, and plant development. During extended dry periods, this juicy portion decreases and is represented as an almost dry or empty water space.
The pineapple fruit is capped by a beautiful crown which some farmers detach during the fruit harvest, and use it for propagation. The crown is a short stem and leaves that bud from the apex of the fruit after about 24 months of planting, typically producing the pineapple fruit, and leaf. Depending on the pineapple specie, the crown accounts for 20 – 80 percent of the fruit in volume. However, the crown could constitute a disposal problem in big farms when its production exceeds the propagation rate, or as a policy, suckers, and slips only are used for propagation. Even though it is clear that retention of the crown on the fruit would increase logistical expenses during storage, and transport, pineapple industries in different countries deal with the waste in different ways. The waste is usually non-toxic and represents a source of plant fiber, and bioactive elements, especially proteolytic enzymes. Pineapple leaves, crown, and stem have a rich supply of bromelain along with additional cysteine proteases. Bromelain is one of the main sources of proteins used in the food industry, production of makeup, and in nutritional supplements. Aqueous extracts of pineapple leaves have also been reported to have some potential effects on gastrointestinal nematodes of ruminants.
One of the potential approaches to managing pineapple field wastes is transforming them into animal feeds. Since the wastes are rich in fiber, and bioactive substances, they can be used as energy sources as well as digestible feedstuffs for ruminants, poultry, pigs, and pets. Several studies have reported a significant increase in milk production when dairy cows were fed diets containing pineapple field wastes, due chiefly to the fiber content of these wastes. However, pineapple field wastes have limited storage life because of their high moisture contents and will require some form of conservation treatment to extend their use as animal feedstuffs. Thus, ensiling pineapple field wastes to improve their keeping quality, and also converting them into pellets to increase their bulk density, storability, and reduce their cost of transportation has been adopted as suitable handling methods.
Chemical composition of pineapple field wastes
More than half of the pineapple leaf is made up of water held in storage parenchymatic cells, thus ensuring minimal evapotranspiration from the leaf. Researchers at the Universiti Putra, Malaysia, evaluated the chemical compositions of pineapple leaves, and stem as well as their fiber compositions, and reported that they are similar in dry matter, and crude fat contents, while the stem has higher carbohydrate and crude fiber contents as shown in table 1. The leaves however have much higher crude protein value than the stem. Other reports on the proximate compositions of pineapple leaves gave the protein as 8.47 percent, fiber 17.89 percent, acid detergent fiber 25.87 percent, and neutral detergent fiber 42.28 percent, indicating that the leaves can be used as a component of mixed ration for dairy cattle, without any effect on milk production. Invariably, the crude protein content of the leaves is marginal, while that of the stem is low, indicating that supplementation with extra protein sources may be needed to optimize their feeding values. Again, the crude fiber contents are high, and comparable to those of palm trunk, fronds, and press fiber which are 37.6, 38.5, and 41.2 percent respectively. Thus, the fact that pineapple field wastes are high in fiber makes them good sources of digestible fiber for ruminant feed.
The pineapple crown extract has is also reported to contain some levels of fructose (0.83 percent) and glucose (0.51 percent). Phyto-screening of leaves for secondary metabolites has revealed the presence of coumarin, terpenoids, phlobatannin, alkaloids, phenols, saponin, quinone, cardiacglycoside, steroids, flavonoids, indicating that they have prominent antioxidant property, and are therefore medicinal. Some of these phytochemicals are also known anti-nutrients which may affect the feeding value of the leaves when used as feedstuff. Again, some of the phytochemicals have proven pharmacological benefits that could be exploited in animal disease management. Particularly of interest among these active ingredients exhibiting pharmacological activities, are bromelain, gallic acid, vianain, caffeic acid, p-coumaric acid, and cysteine protease among others that may serve as animal growth promoters. Again, the leaves have appreciable concentrations of minerals such as phosphorous, potassium, calcium, copper, sulfur, manganese, magnesium, chlorine, molybdenum, zinc, boron, and iron.
Improving the feeding value of pineapple field wastes
Several methods have been used to enhance the keeping quality and nutrient values of fresh pineapple wastes. These methods include drying, and pulverization, fermentation/ensilage, pelleting, blending with other feedstuffs as well as nutrients, and chemical extraction. For example, pineapple field wastes could be ensiled before feeding to ruminants to preserve and improve their nutrient values and digestibility. Silage can be kept for longer periods of time, and can therefore help to alleviate malnutrition in ruminants during the dry season, or other periods of forage scarcity. Pineapple waste silage has been reported to be particularly of good quality because of its high digestibility and palatability.
Researchers at the King Mongkut’s Institute of Technology Ladkrabang, Bangkok, Thailand, evaluated the effects of ensiling blends of whole pineapple plants and Leucaena leaves. The treatments were 100 percent pineapple plant, pineapple plants mixed with 5 percent Leucaena, pineapple plants mixed with 10 percent Leucaena, and pineapple plants mixed with15 percent Leucaena. One percent NaCL2 was added to each treatment and ensiled for 21 days in tightly sealed plastic containers at room temperature. The products were found to be aromatic, and acidic like pickled fruit, while the treatment containing 15 percent Leucaena leaves gave the highest crude protein (8.19 percent), and metabolizable energy (3,697.17 kcal/k) values. The percentage of crude fiber reduced with increasing Leucaena leaf inclusion in the silage, indicating that Leucaena leaves could improve the quality of pineapple leaf silage produced for ruminants and pigs. Similarly, pineapple stem residue generated during bromelain enzyme production has been mixed with peel residues derived from canned pineapple production at 50: 50 ratios, and ensiled in two-layered plastic bags for 21 days. The product on analysis recorded 28.3 percent dry matter, 4.6 percent crude protein, 13.6 percent crude fiber, and 72.8 percent total digestible nutrient, which was much higher than that of corn and Napier grass silages.
One of the proven approaches to managing bulky biomass residues is their conversion to animal feed by the densification process. Densification of biomass into pellets has been shown to increase their bulk density, improve storability, reduce transportation costs, and enable easier handling. Researchers at the Universiti Putra, Selangor, Malaysia, experimented on the pelleting of pineapple leaf, and stem wastes as by-products generated from pineapple pruning. The pineapple leaves and stems were manually chopped and washed with clean tap water. They were thereafter macerated to achieve 2 - 3 cm size and then dried in an oven at 60ºC for 72 hours to conserve their nutrients. The samples were ground to achieve a uniform 1 mm particle size, and dried again for 24 hours, before moisturizing them with clean water to achieve between 35 and 50 percent moisture content. They were then compacted in an extruder at a fixed temperature 100ᵒC, screw speed of 150 rpm, and die diameter of 8 mm to produce the pellets. The physical properties of the pellets measured as friability, bulk density, true density, and porosity were reported to be in the range of 0.85 - 1.22 percent, 303.31 - 345.24 kg m-3, 1502.65 - 1520.35 kg m-3 and 77.022 - 80.05 percent, respectively, while the length was fixed at 3 cm. The researchers concluded that the conditions for optimal pellet production were 35 percent moisture content, the lowest value of friability (0.85 ± 0.28 percent), bulk density (1520.35 ± 0.35 kg m-3), and porosity (80.05 ± 0.86 percent).
The nutritive value of pineapple field wastes for ruminants
Pineapple stem, leaves, and crown have been processed into ruminant feedstuff in many Asian, and South American countries. Generally, feeding dairy cows with pineapple wastes can increase milk yield due to their highly digestible fiber content. A study at the Kasetsart University, Nakhon Pathom, Thailand, evaluated the effects of pineapple stem by-product silage as feedstuff in total replacement of Napier or corn silages on growth performance, and carcass characteristics among other performance parameters of Holstein crossbred steers. The stem by-product was derived from bromelain enzyme production and was ensiled for 21 days before being used to replace Napier grass or corn silage at 50: 50 ratios in the diets. The diets were fed ad libitum to the steers for six months. They reported that the steers fed diets containing the pineapple stem by-product or corn silage recorded the best feed conversion ratios, and carcass characteristics in terms of rib eye areas, while meat quality was not affected by the treatments. The lowest feed cost per gain was however achieved with the pineapple stem by-product, indicating that such diets have the potential to reduce the cost of beef production.
Feeding of dairy animals with whole pineapple plants silage as their only source of roughage for a prolonged period has been reported to result in reduced milk yield, and live weight gain, with manifestations of abnormalities such as rough hair coats, and pica. However, supplementation of such diets with 2.7 kg lucerne hay was shown to improve the milk yield and correct the abnormalities. Therefore, high nutrient containing leaf meals like Leucaena, cocoyam, and cassava leaf hays have been used to improve the nutrient quality of pineapple plant silage for ruminant feeding. Pineapple hay fed dairy cattle have however been reported to produce the milk of better quality in terms of rancidity and flavor scores.
Pineapple leaves are claimed to exhibit some anthelmintic activities against worms, especially in ruminants. However, very few studies have been carried out to investigate these claims. Researchers at the Sylhet Agricultural University, Bangladesh, compared the anthelminthic activity of neem leaves, pineapple leaves, and commercial levamisole HCl against gastrointestinal nematodes of sheep at 100 ml oral dosing of 10 percent water extract of the leaves per sheep and 8 mg/kg body weight of Levavet®. Significant reductions in worm egg counts were recorded with the three treatments, indicating that 10 percent of water extract (w/v) of both neems and pineapple leaves have some potential effects on gastrointestinal nematodes of sheep. In another study carried out at the Bangladesh Agricultural University, Mymensingh, Bangladesh, pineapple leaf was reported as an effective substitute for other anthelmintics like ivermectin, albendazole, and piperazine citrate.
The nutritive value of pineapple field wastes for poultry
Pineapple leaves have been incorporated into poultry feeds chiefly to exploit the benefits of their various phytogenic compounds of known pharmacological properties, including phenolics, flavonoids, and antioxidants among others. Specifically, the pharmacological activities of bromelain have been exploited. In a study at the KNOTUS Co., Ltd. Research Center, Guri-Si, Gyeonggi-Do, Republic of Korea, researchers evaluated the effects of pineapple leaf powder on broiler performance. Day-old broiler chicks were fed a basal diet supplemented with 1, 2, and 3 percent pineapple leaf powder or 50 mg/kg zinc bacitracin as growth promoters for 35 days. The study showed that the 2 and 3 percent pineapple leaf powder supplementations had similar broiler performance improvement as the zinc bacitracin. Specifically, Body weights were significantly increased by 1.06, 5.67, 13.15, and 11.92%, respectively, while feed conversion ratios were decreased by 2.36, 8.49, 12.06, and 11.43%, respectively, in the 1, 2, 3 percent pineapple leaf powder and zinc bacitracin supplemented groups respectively. Similarly, the 2 and 3 percent pineapple leaf powder supplementations decreased the caecal coliform and E. coli populations, but increased the lactobacillus population, indicating that the leaf powder can be used as a supplement in the diet of broilers.
In another study at the Ataturk University, Erzurum, Turkey, researchers evaluate the effects of dietary bromelain supplementation at 0.15, 0.30, and 0.45 g/kg on laying performance, and egg nutrient profile, among other measurements over 8 weeks of feeding trials. The results showed that bromelain supplementation was able to significantly increase egg yolk, and serum protein concentrations, while decreasing egg yolk triacylglycerol fraction, and serum cholesterol concentrations, indicating that bromelain supplementation at 0.45 g/kg is beneficial to the health, and performance of laying hens.
The nutritive value of pineapple field wastes for pigs
Pineapple field wastes have also been processed into quality feedstuff to replace some of the more expensive concentrates feeds used in producing pig diets. This approach has particularly been used to address the environmental pollution concerns arising from the accumulation of pineapple wastes in the field. Such pineapple leaf-based diets have been shown to enhance the feeding mode of growing and fattening pigs, improve meat quality, and taste as well as reducing the dependence on imported feedstuff, which ensures sustenance of livestock husbandry development in tropical countries. Researchers at the Chinese Academy of Tropical Agricultural Sciences, Zhanjiang, China, evaluated the effects of fermented pineapple leaf residues from the fiber extraction process on the growth performance, and meat quality of growing and fattening pigs. The leaf residue was parked in the food-grade plastic drums for compaction, sealed and fermented for 30 days to produce an acid smelling, yellowish-green product of pH 3.8 to 4.4. The fermented pineapple leaf residues were included at the rate of 4, 8, and 12 percent in the diets of the pigs during 90 days feeding. The average daily weight gains of the pigs fed the fermented pineapple residues were 0.9, 0.81, and 0.79 kg respectively, while that of the control pigs was 0.85 kg, indicating that the feedstuff can support efficient gains in growing and fattening pigs. Meat quality attributes such as flesh color, dripping loss, pH, and cooking loss were also superior in the pineapple residue fed animals.
Dietary supplementation of bromelain at 0.1 to 0.2 percent levels has also been shown to improve the growth performance, and dry matter digestibility, while decreasing E. coli and fecal NH3 gas emission from growing pigs fed corn-based diets. Specifically, bromelain supplementation showed statistically significant effects on average daily gain and average daily feed intake of the growing pigs.
Field pineapple wastes such as leaves, stem, and crown generated during pruning, and replanting activities at farm sites are usually discarded as wastes, and may be left to decompose at the farm site or are burnt. These wastes can however be processed into valuable feedstuffs for feeding different classes of livestock. Extracts from the wastes such as bromelain have also been used to improve the production performance of poultry and pigs.
Ajila, C.M., Sarma, S.J., Brar, S.K., Godbout, S., Cote, M., Guay, F., Verma, M. and Valéro, JR. (2015). Fermented apple pomace as a feed additive to enhance growth performance of growing pigs and its effects on emissions. Agriculture, 5: 313-329.
Buliah, N., Jamek, S., Ajit, A., and Abu, R. (2018). Production of dairy cow pellets from pineapple leaf waste. 6th International Conference on Environment (ICENV2018). 020048-1–020048-5; https://doi.org/10.1063/1.5117108
Hattakum, C., Kanjanapruthipong, J., Nakthong, S., Wongchawalit, J., Piamya, P., and Sawanon, S. (2019). Pineapple stem by-product as a feed source for growth performance, ruminal fermentation, carcass, and meat quality of Holstein steers. South African Journal of Animal Science, 49(1): 147 – 155.
Jihua, D., Mingfu, L., Junyan, H., Jin, Z., Wenwei, L., and Tao, H. (2017). Influence of microbiological fermented feed made from pineapple leaf residues on growth performance and meat quality of growing and fattening pigs. Advances in Engineering Research (AER), 135: 646 – 650.
Rahman, M.M., and Yang, D.K. (2018). Effects of Ananas comosus leaf powder on broiler performance, hematology, biochemistry, and gut microbial population. Brazilian Journal of Animal Science, 47: e20170064, 2018.
Shaha, A.C., Hossian, M.A., Islam, M.S., Akanda, M.R., Rahman, M.M., and Hasan, M.M.I. (2015). Comparative efficacy of neem leaves, pineapple leaves, and levamisole against astrointestinal nematodiasis in sheep. Wayamba Journal of Animal Science, P1201 - P1209.
Suphalucksana W., Sangsoponjit S., Srikijkasemwat K., (2017). Using Leucaena to improve the quality of pineapple plant silage. Chemical Engineering Transactions, 58: 847 - 852.
Yenice, G., Iskender, H., Dokumacioglu, E., Kaynar, O., Kaya, A., Hayirli, A., and Sezmis, G. (2019). Dietary bromelain supplementation for improving laying performance, egg quality, and antioxidant status. Europ. Poult. Sci., 83. 2019, DOI: 10.1399/eps.2019.272
Zainuddin, M.F., Shamsudin, R., Mokhtar, M.N., and Ishmail, D. (2014). Physicochemical properties of pineapple plant waste fiber from the leaves and stems of different varieties. BioResource, 9(3): 5311 – 5324.
Zainuddin, M.F., Rosnah, S., Mohd Noriznan, M., and Dahlan, I. (2014). Effect of moisture content on physical properties of animal feed pellets from pineapple plant waste. Agriculture and Agricultural Science Procedia, 2: 224 – 230.