Tick burden in Bos taurus cattle and its relationship with heat stress in three agroecological zones in the tropics of Colombia

Abstract

BackgroundTicks have a negative effect on dairy and beef cattle production systems around the world, with the concomitant risk they represent for the transmission of some important infectious diseases. Colombian cattle breeds are distributed across different agroecological regions and are exposed to different environmental challenges. In humid and warmer climates such as those from the tropics, tick burden and heat stress are important factors that can compromise livestock performance. The aim of this study was to characterize tick burden in four Colombian cattle breeds and evaluate the relationship between heat stress and tick burden in Bos taurus cattle under tropical conditions. Tick counting was conducted in 1332 cattle from Romosinuano (ROMO), Costeño con Cuernos (CCC), San Martinero (SM) and Blanco Orejinegro (BON) breeds, located in the Caribbean, Orinoquia and Andean regions. Vital signs and environmental variables were taken to calculate an adaptability index (AI) and a temperature humidity index (THI). An AI < 2 indicates maximum adaptability while an AI ≥ 2 indicates a state of lower adaptability. In beef cattle, productivity starts to be affected by heat stress when environmental conditions allow an estimation of a THI > 75.ResultsResults showed a differing distribution of ticks on the body of individuals that varied according to the agroecological region. There was a significant effect of breed, sex, family, age and live weight on cattle tick burden. The lowest tick burden was observed in the ROMO breed (12.8 ± 2.6), while the highest tick burden was observed in CCC (31.8 ± 2.3), which were located in the same agroecological region. SM and ROMO animals with an AI > 2 had a higher tick burden than their counterparts that had an AI < 2.ConclusionsCattle breed, sex, age and live weight affect the tick burden in Bos taurus Colombian cattle breeds. The tick burden is higher in cattle with lower adaptability to heat stress. Moreover, it decreases as heat stress levels increase in a tropical environment. The interaction between tick burden and environmental heat stress can be affected by characteristics of the agroecological region itself, the breed and the genetic resistance of the individual tick, as well as the thermal adaptability of cattle.

Research Article Genomic association study for adaptability traits in four Colombian cattle breeds

“…Genes intervening in microorganisms or tick's immune responses in cattle have been associated with adaptive mechanisms. The expression of these genes might explain the higher tick burden in cattle with lower adabtability and higher susceptibility to experience a thermal discomfort (CA >2), as it has been observed in Colombian cattle breeds (Rocha et al, 2019). Another important associated region on BTA19 contains the regulatory associated protein of MTOR complex 1 gene (RPTOR).…”

“…The Colombian Creole cattle have been raised in a tropical environment for centuries, and they are part of conservation and genetic improvement programs, implementing pure and cross-breeding mating systems in order to maintain the genetic diversity of in vivo and in vitro germplasm banks, but also to improve the productivity of cattle populations in the country. Several Colombian cattle breeds show a better reproductive performance measured by age at first calving (AFC) and calving interval (CI) performance (Rocha et al, 2012), disease resistance and high heat tolerance (Rocha et al, 2019), attributes that make these animals an attractive genetic resource (Correal and Henao, 2000). The objective of this study was to perform a GWAS for traits that indicate adaptability such as CA, HTC, AFC and CI in the Colombian cattle breeds BON and SM, identifying genomic regions and genes associated with the phenotypic variance of these traits.…”

Molecular Diagnosis and Phylogenetic Analysis of Babesia Species Isolated From Ticks of Infested Cattle in Wasit Governorate, Iraq

“…Most studies on tick burden in cattle have not evaluated the effect of live weight. Rocha et al (29) showed that in addition to age, live weight also had a significant effect on tick burden as the heavier animal have higher tick burden, and hypothesized that factors contributing to the higher tick burden in heavier animals could be either a compromised immune system in heavier older animals or that larger animals have a wider skin surface with a denser vasculature. Association between sex and tick burden on cattle suggested the role of stress due to milk production and gestation, and the implication of grazing and management strategies.…”

Plant-Derived Natural Compounds for Tick Pest Control in Livestock and Wildlife: Pragmatism or Utopia?

“…In this way, ticks can cause anemia; immunosuppression; decreased feed intake, digestion, and metabolism; reduced milk production and quality; reduced weight gain and body condition; and reduced reproduction (e.g., increasing abortion rates and lowering pregnancy rates). Infection can become significant enough to cause death in some animals [ 44 , 45 , 46 , 47 ].…”