Dairy R&D in SA

PRJ-0336: Diagnostic investigation of sporidesmin toxicity: Histological study

Progress:

The practice of rearing, transport and slaughter of excess dairy calves, in particular bobby calves, is often negatively perceived by the public. From the farmers’ perspective, there is very little use for bull calves and therefore they want to dispose of them as quickly as possible. This should be done as humanely as possible and therefore the project of the Dairy Standard Agency (DSA) as cited below has the intention to improve humane handling of dairy calves over the next five years in a way that is measurable.

Environmental regulations and waste management in SA are governed by the National Environmental Management Act (NEMA) and other related legislation. Waste management, including dairy waste, falls under the jurisdiction of the Department of Environment, Forestry, and Fisheries (DEFF) (Government Gazette, 2013). According to the National Water Act 36 of 1998 (NWA) authorization enables the disposal of wastewater from dairy farming activities into on-site or off-site slurry ponds, as well as irrigation with wastewater from slurry ponds if certain conditions are met, such as the slurry pond must be at least 100 meters away from a stream and 500 meters away from a wetland, and irrigation must be at least 500 meters away from a wetland.

Body condition scoring (BCS) is a subjective manual method based on experience of individuals to assess fat reserves in the cow, of value to milk production, re-conception, regaining reserves and feeding. This is normally done at intervals to assist in monitoring loss and gain in body condition to ensure expected milk production, optimal health, conception and ease of calving. With increasing herd size the manual method is laborious which suggests that if an automated method can be developed which is quick, consistent and accurate, the method would benefit management in time, labour and genetic assessment. Such automated methods based on regression and Convolutional Neural Network (CNN) approaches have been reported in the literature.

The purpose of milking machines is to harvest milk at an optimum speed while maintaining cow comfort and preserving teat functioning against mastitis pathogens. To achieve this, milking machine functioning should be optimal, units should be attached and detached timely, milk let-down should be proper, cows should be handled quietly, mastitis should be identified effectively and equipment cleaned efficiently in case of mastitis, units should be timely adjusted, and alignment should be proper.

Two wastewater streams from the dairy parlour are relevant: (1) wastewater originating from cleaning, disinfection and sanitation of milking equipment, containing water, milk and detergents; and (2) wastewater from floor washing, containing manure, urine, waste milk and dirt. These are usually flooded into wastewater settling ponds which, depending on design, are variably effective in terms of utilisation of irrigation and settled solids thereafter. They do, however, increase the potential risk of surface and ground water contamination, since dairy wastewater contains a variety of suspended and dissolved solids, nutrients, fats, sulphates, chlorides, and trace and soluble organic compounds, and is characterised by a high biological (BOD) and chemical (COD) oxygen demand.

Prelude: Methane emissions in particular, and nitrous oxide as potent greenhouse gases (GHG), have been in the political, activist and general public debate for some time. Central in the debate has been livestock ruminants, in particular beef and dairy cattle, since estimates show the global production of these gases from livestock may be upwards of 20% of total.

Staphylococcus aureus is internationally recognised as the most important pathogen of intra-udder infection and the foremost reason for economic loss to dairy farmers. South Africa is not different, but the spread and antimicrobial resistance (AMR) of different strains compared to elsewhere in the world is not well documented, which then was the main focus of the review by the authors cited.

Several causes of hepatogenous or secondary photosensitisation have been reported, such as from hepatotoxic plants, water-borne cyanobacteria and saprophytic fungi. In cattle, hepatogenous photosensitivity is associated with the feeding of crops comprising certain cultivars and/or hybrids of forage Brassica, namely turnip, rape and swedes. The bovine clinical case is referred to as Brassica-associated liver disease or BALD, which has been well-described in Australia and New Zealand, but not previously in South Africa. Recently, however, a case of infected Holstein cows in the Humansdorp district was reported.

Maintaining soil health is pivotal towards ensuring that the soil can function as a living ecosystem, keeping it in biological balance to ensure productive agriculture. Through the implementation of careful manure management, regenerative farming practices and sustainable cultivation, many dairy farmers contribute to the sequestration of carbon into soil, as well as replenishing soils with other nutrients which are essential for crop cultivation. Controlled manure application is used in South Africa towards the restoration of soils and has shown to reduce dependence on fertilizer inputs.