Controlling the Introduction and Augmentation of Parasites in and on Domesticated Livestock

Abstract

Parasites are one of the most important threats to domesticated livestock worldwide. For several decades, their control has been based only on therapeutic interventions using chemical products at fixed intervals throughout the year. Results have demonstrated that dependence on these chemical products, as a single form of control, is not economically and ecologically sustainable. The problem has been augmented due to the emergence of endoparasite and ectoparasite populations resistant and multiresistant to the primary families of chemical products used to control them. Yet, these chemicals continue to be overused as the primary method for parasite control. Even more, their toxicity to animals, environmental contamination, and economic cost are of increasing concern. This limited approach to parasite control has environmental consequences with likely negative impacts to human and animal health. For example, most endectocides used to control parasites (endoparasites and ectoparasites) in domesticated animals are eliminated in the milk produced by females. Thus, there is strong concern regarding human consumption of dairy products containing such chemicals. Currently, market demands focus on healthy livestock production with emphases on the high standards in animal health and welfare based on quality production practices. The sustainable production of domesticated livestock needs strong changes, such as considering agroecologically oriented as well as novel approaches for parasite control. Thus, the use of existing drugs should be more strategically implemented and combined with other nonchemical alternatives for ruminant livestock. New strategies for controlling parasites in ruminant livestock should begin with the premise of not eliminating or eradicating parasitic organisms, but instead basing actions on economic thresholds (similar to IPM strategies for agricultural crops). In this review, we discuss the problem and current situation regarding parasites and their control using ranching operation methods. We discuss regions where the problem of chemical resistance is of strong concern and include the ecological and socioeconomic effects of parasite control (or lack therefore). We present information about novel approaches such as improving the nutritional status of the host and biological control methods for integration with domestic livestock in order to decrease the use of and reliance on chemical products.

Small Ruminant Production Based on Rangelands to Optimize Animal Nutrition and Health: Building an Interdisciplinary Approach to Evaluate Nutraceutical Plants

“…Therefore, the long-term coevolution between herbivores and PSC necessarily entails the triggering of adaptive responses, which correspond mainly to behavioral and physiological mechanisms that involve both pre-ingestive and post-ingestive processes. Those same mechanisms were used to their full extent when domestic ruminants were introduced to the American continent or to islands such as Australia in more recent years, forcing animals to implement different adaptation mechanisms that have only evolved within the last 500 years [ 6 ]. We encourage readers to consult reviews in this subject in order to gain a complete perspective of the mechanisms by which ruminants cope with PSC [ 18 , 21 , 56 ].…”

“…When domestic ruminants were introduced to the LDF, they also brought their own internal and external parasites. Those parasites also had to become adapted to the new conditions to which they were exposed, particularly the free-living phases that must survive outside the host [ 6 ]. The level of success in the survival of parasites in different environmental conditions is the main cause of differences in the array of parasite species present in each region of the world.…”

“…These ecosystems have served as a source of food for livestock for centuries [ 3 , 4 ]. In many parts of the world, these systems provide the main forage resource for traditional livestock [ 5 , 6 ] or represent the only commodity available to very poor communities [ 7 ], affecting the livelihoods of millions of people.…”

Entomopathogenic Fungi for Tick Control in Cattle Livestock From Mexico

“…Results have shown that dependence on these chemical products, as the only form of control, is neither economically nor ecologically sustainable. Sustainable cattle production needs strong changes, such as considering both agroecology-oriented and novel tick-control approaches (Alonso-Díaz et al, 2014 ). This latter has motivated the exploration of alternative methods for tick control (Samish et al, 2004 ), such as the use of entomopathogenic fungi (EPF).…”

“…When ectoparasiticides are administered correctly (dosed and targeted), they are effective and have wide safety margins for both the animals and the people who apply them. However, there are factors such as resistant or multiresistant parasites and/or incorrect ways of applying the medications, which decrease their effectiveness (Alonso-Díaz et al, 2014 ). Currently, global results reveal that parasite control schemes based on a rigorous and exclusive use of chemical applications are not sustainable.…”