Estimated reading time: 9 minutes
Animal welfare, nutrition, and farm management were some of the hot topics discussed at this year’s final round of the University of Pretoria’s Faculty of Natural and Agricultural Sciences’ Animal Science Symposium for final year students held in Pretoria last week.
Several top students were given the opportunity to present their research papers in front of external industry representatives, lecturers from the department, classmates, and Plaas Media.
The winner of the final round will be announced later in November during a formal prize-giving ceremony.
Seaweed as a feed additive
The first presenter was Liza-Mari Snyman who spoke about the inclusion of seaweed as a potential feed additive in ruminant feeding systems. She argued that seaweed could potentially create a more sustainable agricultural environment because it could protect natural resources, lead to decreased greenhouse gas emissions from cattle, and potentially benefit both animal and human welfare.
Brown, red, and green seaweed were included in the literature overview. While the results varied between the types of seaweed and the breed of cattle that were used, the literature showed enough beneficial evidence that there could be merit to her hypothesis.
Currently the biggest constraints for seaweed as a nutritional additive are a lack of research and variable results. The long-term impact remains unknown, as well as the possible toxicity of the additive.
Beta antagonists and animal welfare
Tristan Prinsloo addressed the ethical and welfare implications of the application of beta antagonists in livestock.
Since beta antagonists were first introduced to the South African livestock industry during the 1990s, the industry’s focus has shifted towards producing high quality food in a more ethical and humane manner, while ensuring food safety for humans.
This has led to growing concern over the impact of the use of beta-adrenergic agonists on animal welfare and human health. These agonists are used in feed additives to increase production.
Prinsloo said research indicated that some of these stimulants increased mortality among beef cattle. And while it increased the respiration rate among animals, it did not increase the heat load on them as body temperatures remained constant. Other research indicated that the use of these stimulants could lead to fatigued cattle syndrome, as treated cattle lied down 31% more than untreated animals. Treated pigs also became exhausted quicker and higher dosages could lead to decreased bone mass and strength.
However, Prinsloo said when agents were administered in small doses within the set perimeters, they were safe, because problems usually arose after overdosing. Therefore, the feed additives were still very useful, as it increased production.
However, due to contrasting findings, Prinsloo suggested that additional research was needed to fully comprehend the effect of these agents on animals and humans. “It is our responsibility to handle livestock as ethically as possible, while adhering to the regulations so that we do not compromise animal welfare.”
Selection and animal welfare
Nicolene Booyens spoke about the impact of artificial selection on small-stock health and welfare. While sheep and goats were historically used to provide milk, wool and meat for households, the modern world has commercialised animal production to ensure optimal productivity and efficiency. However, it seems to have come at the expense of animal health and welfare.
Booyens said breeding programmes have been implemented to drive the optimisation of production efficiencies, which is a data driven approach: Better wool yield, growth rate, and reproduction. “The downside to this approach is that it ignores behavioural and immune system traits,” Booyens said, adding that it also reduced resilience to environmental stressors.
The unintended consequences of higher fertility were that it led to a larger litter with reduced birthweights and higher mortality rates. Similarly, increased fleece yield has led to a higher wrinkle score and an increase in parasitic infections in animals. Increased milk production has led to a higher somatic cell count, which has increased the risk of mastitis in animals.
Consequently, a shift towards a goal driven approach is currently taking place to include health and welfare traits. The sustainable benefits of this far outweighed the outdated approach of breeding merely for production efficiency and profitability.
Sunflower meal in broiler feed
Masina Lungile looked at sunflower meal as a replacement for soya bean meal in broiler chicken feed.
As feed accounts for 75% of broiler production costs and soya bean meal is the main protein component thereof, Lungile argued that there was a global need to source a less expensive alternative.
After doing her research she concluded that sunflower could be a good alternative to alleviate the industry’s over-reliance on soya bean meal as a protein source. While there are certain limitations with regard to sunflower meal’s composition, this could be overcome through supplementation and the containment of amino acids. Lungile believed this could indeed help to lower production costs.
Heat stress in feedlots
Ivan Coetsee studied the effect of heat stress on feedlot cattle’s performance. The reason why he believes this to be an important issue for the industry is the fact that South Africa’s climate is projected to increase by 2°C over the next decade.
Animals possess the ability to thermoregulate themselves. However, both the environment and an animal’s metabolism (through feed) can emanate so much heat that thermal regulation becomes impossible. “It is important to note that both the intensity and duration of heat is critical,” Coetsee said. “Despite night cooling, heat can be accumulated over a few evenings and that is where the problems start occurring.”
Additionally, when it comes to heat stress, everything is interlinked and hence it is important not to believe that a single symptom stands in isolation.
As animals are biologically programmed to always prioritise maintenance rather than growth, Coetsee said it was important to keep animals as stress free as possible; mitigation was therefore needed. However, some ideas, such as misting systems sounded good in theory, but weren’t practical. “These systems require regular maintenance and access to adequate clean water, which isn’t always possible.”
While nutritional strategies were effective, affordable and practical, there were concerns when it came to the adaptation of feed. Coetsee believes shading could be the best option, although further research would be beneficial.
Moo-sic for improved production
Monique Combrink looked at music as a form of production enrichment in dairy cattle, swine and poultry systems.
In dairy cattle music gave rise to an increase in serotonin levels, lower stress levels, increased oxytocin levels, increased milk letdown, reduced milking time, increased milking speed, and a decreased respiration and heart rate. The animals were also less fearful of humans.
Essentially, the playing of slow music in noisy milking parlours benefited the farmers themselves, decreased stress levels and increased milk yield by 3%.
However, if sound is not implemented correctly, it could lead to the sounds in the milking parlour competing with the music which will result in an unpleasant noise.
In respect of pig production, different music genres led to different reactions. The animals were either aggressive or playful, depending on whether classical music or rock music were played. Dissonant music led to negative emotions, while consonant music led to positive reactions.
When it came to poultry, music helped to cover up background noise in broiler houses. However, long term exposure to loud noise caused stress in poultry. This led to a decrease in egg production and productivity, as well as an increase in mortalities.
Grain for guts
Larissa Kroon discussed the impact of cereal grain type, particle size, and feed form on the digestive microflora of broilers.
The early establishment of microflora is critical, as it leads to improved welfare, better gut health, better growth, and a decrease in the need of antibiotics because of the establishment of a better immune system. Kroon said every part of the chicken’s digestive system has its own set of microflora, which leads to the establishment of a completely different ecosystem.
Kroon’s research showed that the type of grain fed during the starter period had a direct impact on a bird’s digestive system, because each type of grain contained its own unique blend of micro-organisms.
However, the processing parameters – such as processing temperature – will also have an impact on the micro-organisms, which will in turn impact gut health.
A finer particle size could also lead to the growth of unwanted microflora (e.g. Acinetobacter), while coarser particles decrease good microflora (Lactobacillus). Whole particles have the opposite effect.
Longevity in dairy cows
Ending the day was Cilé-Mari Schultz, who discussed the nutritional programming of reproductive development in dairy cattle and the impact of pre- and neonatal nutrition on long-term fertility.
Schultz said declined fertility was the most common cause of premature culling in dairy herds. Therefore, improving fertility was very important and there were three ways to achieve this:
- Breeding and genetics.
- Reproductive management.
- Nutritional programming.
Schultz decided to focus on the latter, which meant evaluating the potential of nutritional programming as a strategy to improve fertility in dairy cattle. She considered both prenatal nutrition (in utero) and neonatal nutrition (the first few weeks of a calf’s life). In the end she found that research indicated the highest positive impact if intervention happened during the neonatal stage.
However, basic reproductive management needed to be prioritised before nutritional treatments were applied. And when treatment was applied, Schultz also said that the timing and type of nutrition was critical.
– Susan Marais, Plaas Media
