2013 Annual Report
Initial analyses of phytoplankton byproducts showed that the protein levels were acceptable for culturing such omnivorous species as tilapia and prawns but for carnivorous species, additional supplements might be required. Conversion of organic materials by saprophages has gained popularity in the last decade and larvae of the black soldier fly, Hermetia illucens, have been shown to be capable of converting large amounts of organic waste into protein rich biomass. The larvae could serve as a substitute for fishmeal or fishfood.
Hawaiin swine farms are mostly small family farms with limited land, limited resources and limited economies of scale. Although there is a high demand and market for local pork in Hawaii, feed cost was identified as one of the top weaknesses of the swine industry. To feed the swine, no local grain-based diet is produced in Hawaii and most of the commercial feed ingredients or compound feeds are shipped from the mainland US, which again adds to the feed cost, an additional burden for farmers. There are some agricultural products like macadamia nut, papaya, cassava etc. and their byproducts like wheat mill run, macadamia nut press cake and many others are available. The nutritional values of these products need to be determined to incorporate in swine diets. This project is expected to identify potential local feedstuffs and characterize their nutritional value and in vitro digestibility so that sustainable swine feeding programs can be developed using local feedstuffs.
About 30 agricultural products and co-products were collected from different islands of Hawaii, after discussion with farmers/industry and other stakeholder on their availability and potential use in swine feeding. All the collected samples were ground and proximate analysis was conducted following standard analytical procedure. Dry matter content of leaves were low and ranged between 17-42%, as all of them were succulent green leaves and moisture content in them was high and highest in commercial pellet feeds which ranged from 95-99%. Neutral detergent fiber content was found high in the leaves (moringa, cassava, sweet bettle) which ranged between 43-47%, and also in macadamia nut press cake (41%), and Tofu scrap (36%), but the highest was found in barley brewer's waste (58%). Lipids in commercial feeds were low and ranged just between 1-3%. The lowest was found in maize. Cassava, yam discorea alata and kuhukuhu papaya had high lipid content ranging between 11-13%. The highest lipid content was found in macadamia nut press cake (21%). Nutrient profile of these feedstuffs varied widely. Other nutrients analysis and in vitro digestibility study is in progress. This information will be useful to develop swine feeding programs using local feedstuffs.
Identifying and developing tropical forage grasses that have robust biomass production under water-limited agroclimatic conditions will increase the amount of land suitable for grazing cattle and decrease production costs. The current project will determine the yield and nutrient content of eight varieties of tropical forage grasses under irrigated and rain fed conditions at Waimanalo Research Station in Waimanalo, Hawaii.
The eight varieties chosen for the study include four varieties of pearl millet x napiergrass (PMN) hybrids developed in Hawaii and four napiergrass varieties. The trial was harvested at approximately four months after planting, weighed, and oven dried to determine dry matter yields. The top two yielding varieties are both PMN hybrids. The nutrient content of forage is critical for efficient cattle production. Nutrient analysis of the forage samples is in progress.