A simple technology for production of vegetable-carried blood or rumen fluid meals from abattoir wastes

Abstract

The study was designed to develop simpler and quicker processing methods for converting major abattoir wastes ( i.e., blood and rumen contents) into blood meal and related products using vegetable carriers of milling (wheat offal (WO) and maize offal (MO)), brewery (brewers’ dried grains (BDG)), and abattoir (dewatered rumen contents (RC)) processes as absorbents. Vegetable-carried blood or rumen fluid meals were obtained by absorbing cattle blood that had been prevented from coagulating, or rumen fluid from rumen contents after dewatering, or a blood and rumen fluid mixture with each of the vegetable carriers before sun drying and milling. Fourteen products obtained were in four categories being: vegetable carriers with blood absorbed once or twice comprising brewers’ dried grains blood meals 1 and 2 (BB1 and BB2), maize offal blood meals 1 and 2 (MB1 and MB2), wheat offal blood meals 1 and 2 (WB1 and WB2), and dewatered rumen contents blood meals 1 and 2 (RB1 and RB2). Another was vegetable carriers with rumen fluid absorbed once comprising brewers’ dried grains rumen fluid meal (BRF), maize offal rumen fluid meal (MRF) and wheat offal rumen fluid meal (WRF). The last was vegetable carriers with a blood and rumen fluid mixture absorbed once comprising brewers’ dried grains rumen fluid and blood meal (BFB), maize offal rumen fluid and blood meal (MFB), and wheat offal rumen fluid and blood meal (WFB). The products were sun-dried for 2–4 h to moisture contents of 60–110 g/kg. Chemical composition of the products indicated a good potential nutritional quality. Gross energy and crude protein concentration ranges were approximately 17–20 MJ/kg dry matter (DM) and 132–530 g/kg DM, respectively. However, fibre concentrations were relatively high (120–320 g acid detergent fibre/kg DM) for most of the products and mineral concentrations were marginal. The low technology procedure developed used simple tools amenable to micro-, small- and medium-scale applications to convert of blood and rumen contents to potential animal feeds.