Presentation Overview

  • Title: Use of unsaleable vegetables as animal feed

    • Presented on behalf of Prof. Alex Chaves, SOLES - Faculty of Science by Dr. Daniel Forwood, Meat & Livestock Australia

Learning Outcomes

  • Understanding Food Waste Usage:

    • Importance of using food waste, such as unsaleable vegetables, in animal feed.

  • Methods of Food Waste Conservation:

    • Describe various conservation techniques to manage food waste.

  • Conversion to Ruminant Diet:

    • Understand how food waste can be safely converted into a ruminant diet.

  • Effects Analysis:

    • Assess the impacts of unsaleable vegetables on:

    • Silage quality and associated microbiome.

    • Performance metrics in sheep and the characteristics of carcasses.

Presenter Background

  • Academic Qualifications:

    • Studied Animal and Veterinary Bioscience (Honors I) focusing on Animal Production Systems.

    • Graduated in 2018 after a curriculum including placements.

  • PhD Engagement:

    • Transitioned to the University of Queensland for PhD specialism in Ruminant Nutrition.

    • Graduate in 2022 with involvement in studies beyond core thesis work.

  • Current Position:

    • Moved into the industry post-graduation, focusing on Farming Systems Policy, Innovation, and R&D Project Management with Meat & Livestock Australia.

Food Waste Statistics

  • Cost of Food Waste (Various Countries):

    • Presented in USD millions, adapting data from multiple studies (Parfitt et al., 2010; Zhou, 2013; de Lange and Nahman, 2015; Shambavi and Ipshita, 2015; Bolan and Tsang, 2018).

  • Food Waste in Australia:

    • Australians waste approximately 4.06 to 4.4 million tonnes of food annually, costing AUD 8.4 billion (approximately AUD 954.86 per household).

    • Disposal via landfill leads to the rapid degradation of organic matter, generating approximately 6.8 million tonnes of greenhouse gases (GHG), notably carbon dioxide (CO2) and methane (CH4) (Bolan and Tsang, 2018).

    • Highlights significance of minimizing GHG emissions by redirecting food wastes before landfill disposal.

Practical Examples of Food Waste Sources

  • Carrot Processing Plants:

    • Example of waste management at carrot processing facilities.

  • Waste Examples from Kalfresh Vegetables:

    • Specific instances of vegetable waste generation (Fassifern Valley, QLD).

Historical Context & Feeding Practices

  • 2018 Feeding Trials:

    • Feeding trials conducted involving 460 sheep, weights ranging from 230 to 450 kg.

    • Up to 42 tonnes (as-fed basis) of waste vegetables utilized per day.

  • Feeding Logistics:

    • Historical method included feeding 18 to 24 tonnes of carrots daily on the ground.

    • Transitioned to usage of feeding mats to facilitate efficiency.

Methodologies in Food Waste Utilization

  • Food Waste Conservation Techniques:

    • Silage Production:

    • Mixed vegetables were silaged utilizing mini-silos. Research tracked epiphytic counts before ensiling, during, and post-ensiling with and without inoculants/probiotics.

    • Discussed optimization in harvest ranges to minimize losses due to immaturity or inadequate moisture, essential for effective ensiling.

  • Six Phases of Silage Fermentation and Storage:

    • Adapted from McCullough, featuring processes from cell respiration to aerobic decomposition upon oxygen exposure.

  • Additives:

    • Overview of various fermentation stimulators including enzymes, inoculants, molasses, sugar, prebiotics/probiotics, and new generation silage inoculants.

Research Insights

  • Impact of Vegetable Mixtures on Silage Quality:

    • Projects assessed the microbial characteristics and fermentative properties of maize ensiled with unsalable vegetables including carrots and pumpkins.

  • Experimental Design & Results:

    • Various treatments tested with maize and differing levels of carrots or pumpkins ensuring controls without inoculants versus those with.

    • Data indicated that silage quality improved with vegetable addition owing to greater in vitro digestibility, total volatile fatty acids (VFA), and acetic acid in comparative trials.

  • Microbiome Analysis:

    • Details provided on alpha diversity of silage bacterial and fungal communities in relation to vegetable mixtures, implicating operational taxonomic units (OTUs).

Sheep Performance Trials

  • Controlled Feeding Trials:

    • Comparison of control diets against carrot-based formulations over a defined feeding schedule, measuring parameters such as dry matter intake (DMI), average daily gain (ADG), feed conversion (FC), and carcass characteristics.

    • Data reveals significant improvements in live weights and feed conversion ratios when carrots were included in diets.

  • Meat Quality Parameters:

    • Carcass characteristics showed weight metrics where lambs on carrot diet showed notable differences in hot and cold carcass weights, while quality indices like shear force and drip loss remained consistent across treatments.

Conclusion on Food Waste Utilization

  • Global Food Waste Response:

    • Emphasizes the necessity of a cohesive global approach to mitigate environmental and economic repercussions of food waste, advancing the case for recycling unsalable vegetables as supplementary feeds.

    • Cites food waste from vegetables comprising 23% of global food waste and 40% of Australian food waste by weight, reinforcing its significance as a resource in livestock nutrition.