Department of Animal Production and Technology

Strategies for valorization of crop residues into biofuels and other value-added products

Wed, 04 Aug 2021 00:00:00 GMT

Strategies for valorization of crop residues into biofuels and other value-added products Kamusoko, Reckson; Raphael M., Jingura,; Parawira, Wilson; Chikwambi, Zedias Agricultural systems produce vast amounts of crop residues (CR) as by-products. More than 200 billion tonnes per year of CR are produced worldwide. They are mostly used as animal feed or disposed of by incorporation into soil for fertility purposes and by burning. Traditional CR management practices have environmental and techno-economic implications. Crop residues are an excellent bioresource, with multiple untapped applications. There is a significant lack of knowledge about commercializing the conversion of CR into value-added products in a sustainable way. A biorefinery concept is an important option that can transform CR into useful products. This paper reviews the potential state-of-the-art options for valorization of CR into multiple product streams. The paper focuses on 13 products. These are biogas, bioethanol, biobutanol, biohydrogen, biomethanol, pyrolytic products, enzymes, bioactive compounds, animal feed, mushroom, single-cell protein, organic acids, and biocomposites. The product streams can be divided into three categories: biofuels, animal feed and food, and phytochemicals. Biofuel production is the most promising strategy for the valorization of CR at large-scale biorefineries. Anaerobic digestion and fermentation are preferred to thermochemical conversions because they are cost effective and have improved conversion efficiency. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd

Isolation and characterization of biosurfactant-producing microbes isolated from the gastrointestinal system of broiler birds fed a commercial diet

Mon, 01 Jan 2024 00:00:00 GMT

Isolation and characterization of biosurfactant-producing microbes isolated from the gastrointestinal system of broiler birds fed a commercial diet Chigede, Ngavaite; Chikwambi, Zedias; Mpofu, Irvin D. T.; Madzimure, James Antimicrobial drug resistance (AMR) from improper use of antibiotics in various livestock products is a growing hazard for humans worldwide, with current death rate in excess of 700,000 per annum linked to the problem. Microorganisms are a rich source of structurally distinct bioactive compounds designed to protect the microbes and can offset AMR chal lenge. A study was conducted at Chinhoyi University of Technology to isolate, identify and characterize biosurfactant secreting microbes from broiler bird’s gastrointestinal tract. Analysis of variance was performed in Genstat software. 16S rRNA technique was used to identify the DNA of isolates, annotated by similarity using BLASTn analysis against the NCBI nucleotide database. Phylogenetic analysis was performed on the BLASTn outcome to have an appreciation of the evolutionary genetic relationships. Small intestine-derived samples had a wider hemolytic activity of 5.6mm, with a 39% emulsification index. At 98.29% sequence similarity, the bacterium producing biosurfactants was identified as an Escherichia coli strain similar to the 7.1994/NIST 0056 strain. The biosurfactant substance is a derivative of decane with beta lactams, tetracyclines and sulfa drugs properties which were respon sible for the observed antibacterial activity. We recommend endogenous biosurfactant pro duction optimization experiments and in-vivo trials to evaluate the potential impacts of a biosurfactant based feed additive in broilers

Is neutral genetic diversity related to quantitative variation in semen traits in bulls?

Sat, 01 May 2021 00:00:00 GMT

Is neutral genetic diversity related to quantitative variation in semen traits in bulls? Gororo, Eddington; Chatiza, Fungayi Primrose; Chidzwondo, Farisai; Marshall Makuza, Stanley Conservation decisions based on neutral genetic diversity have been observed to promote retention of useful quantitative variation in biological populations. An experiment was undertaken to determine the association between microsatellite marker polymorphisms and phenotypic variation in semen production and cryosurvival traits in bulls. Thirty-five ejaculates were collected from ten bulls of two breeds and evaluated before and after cryopreservation for several semen traits. The bulls were also genotyped using a set of sixteen bovine-specific microsatellite marker loci. Fixation indices (FST), heterozygosity and Nei's genetic distance measures were computed from allele frequency data for each of the bulls. Molecular and phenotypic data were used to compute tri-distance matrices for the ten bulls and correlated using Mantel's test in GenAIEx 6.5. The study revealed extensive heterogeneity in semen traits, heterozygosity and FST values among the bulls. Large pairwise phenotypic and genetic distances were also observed. Correlation between pairwise genetic distances and phenotypic distances was significant and highly positive for sperm viability (r = .61, p < .001) and moderately positive for sperm motility (r = .40–42, p < .05) variables. For sperm morphology, ejaculate volume and sperm concentration, correlation with genetic distances was positive, low and not significantly different from zero (p > .05). A tendency for a triangular-shaped relationship between genetic and phenotypic distances for post-thaw motility and viability traits was also observed. Accordingly, association with neutral genetic diversity was absent for semen production traits and moderate to highly positive for sperm cryosurvival traits. Given these findings, conservation decisions based on neutral genetic diversity may capture variation in some adaptive traits, but not others.

Effect of whole and clarified egg yolk based extenders on post-thaw semen quality in bulls

Fri, 21 May 2021 00:00:00 GMT

Effect of whole and clarified egg yolk based extenders on post-thaw semen quality in bulls Kamusasa, Prosper; Gororo, Eddington; Chatiza, Fungayi Primrose This study was conducted to evaluate the comparative cryoprotective effects of whole egg yolk and clarified egg yolk on post thaw sperm quality parameters and to determine the optimum clarified egg yolk inclusion level (10-20%) in semen extenders for Mashona bull semen cryopreservation. It was shown that there was a significant decrease in sperm quality variables following cryopreservation. Semen quality increased with the concentration of clarified egg yolk, indicating a positive relationship between egg yolk LDL concentration and maintenance of in vitro sperm quality. The 20% clarified egg yolk (CEY20) extender treatment gave post-thaw motility, viability and normal morphology values which were comparable to the control (20% whole egg yolk, WEY20). The 10% clarified egg yolk concentration gave the least post-thaw quality values and the greatest proportion of defective spermatozoa. This experiment found no advantage of replacing whole egg yolk with up to 15% clarified egg yolk in Mashona bull semen cryopreservation. However, 20% clarified and 20% whole egg yolk performed similarly in the maintenance of post-thaw sperm motility, viability and normal morphology.