The cost of mycotoxins in animal production

Mycotoxins can exert their effects on animals in many ways, including changing feeding behaviour, altering intestinal structure and function, affecting endocrine system signalling and modifying the immune system. Mycotoxicosis can negatively impact all stages of animal production. Exposure to mycotoxins can occur as either a large single dose (acute) or a lesser quantity consumed over time (chronic). Symptoms of mycotoxicosis are often dependent on the type of mycotoxin involved, the concentration and the age or health status of the animal.

Historically, there has been limited availability of risk analysis methods for determining multiple mycotoxins simultaneously in feedstuffs. Today, using an improved liquid chromatography/mass spectrometry method, such as the Alltech 37+ mycotoxin analysis programme (see box), researchers can analyse for multiple mycotoxin contaminations in order to provide valuable information to producers. The Alltech 37+ programme reports not only the levels of mycotoxins measured in a given sample, but also provides a risk assessment that calculates the Risk Equivalent Quantity (REQ) (risk factor multiplied by the quantity of mycotoxins) for that particular feedstuff or finished feed sample. Analysis completed by the Alltech 37+ analytical services laboratory can be utilised for individual samples as well as for analysis of yearly crop contamination.

2015 Harvest Analysis

During 2015, weather patterns presented ideal conditions for the growth of certain moulds and mycotoxins. According to Alltech’s 2015 North America Harvest Analysis of more than 100 corn silage samples submitted from across the United States and Canada, 96% of samples contained at least one mycotoxin, with an average of 3.1 mycotoxins. The most prevalent mycotoxin group found throughout North America was Fumonisins, which were measured in more than 70% of samples. The Type B Trichothecenes and Fusaric Acid groups were also detected in more than 55% of corn samples. The concentrations of these mycotoxin groups were quite variable, ranging from low to very high levels of contamination, depending on location. Additionally, there was some concern that the 2015 corn harvest could contain significant levels of the Type A Trichothecenes and the mycotoxins from the Penicillium group. Results from the 2015 North American Harvest Analysis showed that this commodity may be at greater risk for containing mycotoxins than corn grain. Based on the 116 samples surveyed, corn silage had on average of 5.6 mycotoxins per sample. Within these samples, 71% tested at a higher risk to dairy cows, while 87% were at a higher risk to calf performance. The harvest analysis, conducted by the Alltech 37+ analytical services laboratory, revealed a risk for Type A Trichothecenes, Type B Trichothecenes and Fusaric Acid. Also present in the 2015 corn silage were Penicillium mycotoxins detected in more than 41% of samples.

Reduced growth and performance

Whether it is simply a case of reduced feed intake, or a combination of the various effects throughout the body, mycotoxins can have an impact on growth performance. Research has shown that growth performance of pigs can be reduced at both low and high levels of mycotoxins (Alizadeh et al., 2015; Chaytor et al., 2011). This effect on growth is also shown in broilers, where mixtures of mycotoxins can lower weight gain and feed efficiency (Arvind and Churchill, 2015). In dairy cows, a reduction in milk production is often a sign of mycotoxin consumption. Alejandro et al. (2014) showed that five milligrammes per kilogramme of deoxynivalenol resulted in a 10% reduction in milk production per cow per day; milk quality is also often impacted in cows, with mycotoxins frequently increasing the somatic cell count.

Breeding performance of animals can also be impacted by mycotoxins. In some cases, the effects on reproductive performance may be caused directly by mycotoxins, such as in the case of zearalenone, while in other cases performance changes may be due to the indirect effects of mycotoxins on animal health. Trichothecene mycotoxins have been shown to lower egg production of poultry layers and breeders and may also reduce hatchability rates (Chowdhury and Smith, 2004; Yegani et al., 2006). Sows are shown to have an increased number in stillbirths when consuming a mixture of mycotoxins, while research has shown that cattle can have lower pregnancy rates as a result of mycotoxins (Diaz-Llano and Smith, 2006; Hulik and Zeman, 2014).

Mycotoxins’ relation to animal profitibility

When mycotoxins impact growth and production levels, profitability is also altered. Based on a meta-analysis of scientific literature conducted by Alltech Mycotoxin Management, the link between mycotoxin risk and animal profitability has been estimated. Utilising the average mycotoxin risk level in corn from the 2015 North America Harvest Analysis and prediction equations derived from a summary of several research publications, nursery pigs may have a potential loss of daily gain by 6.8 grammes per day. This loss in gain in the nursery period may in turn result in an additional day required for pigs to reach desired market weight at the end of the finishing period. Grow finish pigs may have an average estimated loss of daily gain from this year’s corn by 24 grammes per day and have a 14% increase in feed conversion rate (FCR). This loss in gain equates to a total decrease of 3.4 kilogrammes per pig over a 140 day period, which may result in a carcass drag of 2.5 kilogrammes or an additional four days required for these pigs to reach the desired market weight. These effects can impact profitability, equating to an estimated average loss of $3.09 per carcass.

The profitability of poultry can also be impacted by mycotoxins. Weight gain may be reduced by three grammes per bird per day with an additional increase in FCR by approximately 5% based on the 2015 North America Harvest Analysis corn harvest results. As a result of the change in gain, birds could require an extra 2.5 days to reach desired market weight or have a reduction in carcass profit at an estimated loss of $0.21 per bird. Layer profitability changes can also be estimated. Over a 62-week production phase, layers may have reduced egg production by 3.8 eggs per hen based on the 2015 North America Harvest Analysis corn harvest results and prediction equations derived from scientific research. Eggs may also be lighter in weight, on average by 0.2 grammes per egg. The impact on egg production subsequently impacts profitability resulting in an average loss of $ 0.42 per hen.

For dairy cows, milk profitability is a primary focus. Utilising scientific literature results and the average risk from the 2015 North America Harvest Analysis corn silage harvest, cows are estimated to have a loss in milk production of 0.6 litres per cow per day. When considered over a 300 day lactation period, this could equate to a grand total of 183 litres, resulting in a loss of $64.82 per cow per year in milk quantity alone.

Preventative measures are essential

By linking research available on animal performance loss with economic factors, a practical understanding of mycotoxin effects can be gained. However, it is not enough to know what mycotoxins cost, but also how to manage mycotoxins from the field to the animal. In order to minimise losses in profitability, preventative measures are essential. 
The management costs of ensuring feed safety through drying grains, proper storage, analytical analysis and mitigation product inclusion can certainly have costs associated with them. However, the paybacks of this prevention can more than outweigh the cost when animal performance and health are considered.

A complete mycotoxin management program allows producers to understand risk, minimise mycotoxin effects and improve animal profitability. As a result, animal producers are able to deal with mycotoxins proactively, rather than 
reactively.

Author:
Alexandra Weaver, Alltech Mycotoxin Management Team