Harnessing Feed By-Products To Boost Early Lactation Milk Yields And Sustainability
In a significant stride towards sustainable dairy farming, recent research conducted by the Agri-Food and Biosciences Institute (AFBI) has demonstrated that feed by-products can effectively boost early lactation milk yields while simultaneously reducing the carbon footprint of dairy operations. This landmark study brings fresh insights into replacing traditional human-edible feed components such as cereals and soyabean meal with alternative by-products that support both productivity and environmental goals.
The AFBI trial involved 88 autumn-calving cows, whose milk production and health were closely monitored from calving through to 150 days-in-milk. Animals were fed a base diet of grass silage supplemented with four distinct concentrate treatments. These ranged from a high human-edible concentrate containing cereals and soyabean meal to formulations excluding soyabean meal, cereals, or both. By-product ingredients like sugar beet pulp, wheat feed, rapeseed meal, distillers’ grains, and maize gluten were substituted for traditional feeds to test their effects on cow performance.
All four concentrates were nutritively balanced for metabolisable energy (12.4 MJ/kg dry matter) and crude protein (155g/kg dry matter), ensuring comparability. The trials revealed a clear trend: reducing the human-edible fraction of the concentrate from 51% (in the cereal-soya concentrate) down to as low as 18% (when both cereals and soya were removed) improved total feed intake, energy corrected milk yield, and fat plus protein yield. Importantly, cows on low human-edible concentrates also achieved a higher Margin Over Concentrate (MOC), indicating better economic returns for farmers.
Reducing reliance on human-edible feed ingredients not only enhances herd productivity but also yields notable environmental benefits. The trial showed that particularly replacing soyabean meal with by-products significantly curtailed the carbon footprint of milk production. This is timely considering the ethical and sustainability concerns emerging around global soya cultivation, including deforestation and land-use change.
FFA Explainer Box: The Human-Edible Fraction of feed refers to the proportion of feed ingredients that could otherwise be consumed directly by humans. Lowering this fraction increases the efficiency of food production and lessens competition between livestock and people for edible crops.
In Zimbabwe, these findings resonate deeply with ongoing efforts to transform national agriculture under the National Development Strategy 1 (NDS1). Sustainable intensification in dairy production is a cornerstone of Zimbabwe’s agenda to improve food security, boost rural livelihoods, and address climate change. By capitalising on readily available agro-industrial by-products such as cottonseed cake, maize bran, and groundnut haulms, smallholder and commercial dairy farmers can reduce feed costs, improve milk yields, and decrease environmental impact.
A practical example is Mrs Tendai Moyo, a dairy farmer in Mashonaland East, who has integrated cottonseed cake and molasses into early lactation rations. She reports improved milk volumes and better herd health—validating the potential of locally sourced by-products as sustainable feed alternatives. Furthermore, Zimbabwe’s revised livestock feed policy encourages the integration of such indigenous feed resources and supports the participation of women and youth, who comprise a large share of smallholder farmers.
The AFBI study underscores that replacing traditional cereals and soya with by-products is not just feasible, but advantageous. It simultaneously addresses ethical concerns related to food use, advances climate-smart agriculture, and enhances economic resilience. This multifaceted impact aligns with Zimbabwe’s vision for an inclusive and sustainable dairy sector.
Looking ahead, fostering collaboration between Zimbabwean agricultural research institutes, universities, and international partners like AFBI could accelerate the adoption of such feeding strategies. Extension services must prioritise training on formulating cost-effective, low human-edible fraction concentrates tailored to local by-products. Special attention to supporting women and youth farmers will unlock greater innovation and productivity gains.
In conclusion, this research marks a pivotal step towards greener and more profitable dairy farming. As Zimbabwe implements its NDS1 goals, adopting feed by-products offers a practical pathway to harmonise productivity, environmental stewardship, and socio-economic development in the dairy sector.
About The Author
