Genetic variation and covariation for growth, parasite resistance and heat tolerance in tropical cattle

Mackinnon, M. J.; Meyer, Karin; Hetzel, D. J. S.

doi:10.1016/0301-6226(91)90090-d

Cited by 115 publications

(65 citation statements)

References 28 publications

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“…The repeatability value obtained for FEC (0.3) was similar to the values found by Stear et al (2000) in sheep and by Mackinnon et al (1991) in crossbred Zebu and Nicolau et al (2002) in Nelore cattle naturally infected with nematodes. Repeatability for PCV (0.42) could be considered moderate and thus could be used together with the FEC to monitor nematode infections.…”

Section: Discussionsupporting

confidence: 63%

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Field study on nematode resistance in Nelore-breed cattle

Bricarello

Zaros

Coutinho

et al. 2007

Veterinary Parasitology

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The present study evaluated Nelore cattle with different degrees of resistance to natural infections by gastrointestinal nematodes. One hundred weaned male cattle, 11-12 months of age, were kept on the same pasture and evaluated from October 2003 to February 2004. Faecal and blood samples were collected for parasitological, haematological and immunological tests. In February 2004, the 10 most resistant and the 10 most susceptible animals were selected based on individual means of nematode faecal egg counts (FEC). Such animals were slaughtered for worm burden determination and nematode species identification. The repeatability estimates for FEC (AES.D.), log-transformed FEC and packed-cell volume (PCV) in all animals were 0.3 (AE0.05), 0.26 (AE0.04) and 0.42 (AE0.05), respectively. The resistant group showed lower FEC and worm burdens than the susceptible group (P < 0.05). There were no significant differences between groups regarding mean body weight, weight gain, PCV and total serum protein values (P > 0.05). The resistant group showed higher total serum IgE levels (P < 0.05) and higher mean eosinophil blood counts. However, the latter was statistically significant only 42 days after the beginning of the study. Nematodes Cooperia punctata and Haemonchus placei were predominant and the correlation between Cooperia and Haemonchus burdens was 0.64 (P < 0.05), which indicated that animals presenting increased numbers of one of those genera probably had increased numbers of the other. The current study provides further evidence of IgE active role in nematode immunity and suggests that total serum IgE level might serve as an additional marker to select Nelore cattle that are responsive to H. placei and C. punctata infections.

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Section: Discussionsupporting

confidence: 63%

“…Similarly, Nicolau et al (2002) did not notice any association among those variables in naturally infected Nelore cattle. In another study carried out in Australia using crossbred Zebu animals, there was a low correlation between resistance to parasites and growth (Mackinnon et al, 1991).…”

Section: Discussionmentioning

confidence: 99%

Field study on nematode resistance in Nelore-breed cattle

Bricarello

Zaros

Coutinho

et al. 2007

Veterinary Parasitology

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“…The genetic correlation between tick and milk traits was negative with large standard errors, while the heritabilities of these traits were similar to previous estimates. Compared with previous estimates the heritability for tick burden in this study was larger than the value of h 2 = 0.15 found in zebu and zebu composite Brahman and Tropical Composite cattle for tick scores (Prayaga et al 2009), but similar to the value of h 2 = 0.41 AE 0.08 calculated for taurine cattle using multiple tick counts (Henshall 2004) and within the range of h 2 = 0.34-0.49 previously calculated for cattle in Queensland (Wharton et al 1970;Mackinnon et al 1991). Heritabilities for the milk yields were similar to previously estimated values for these traits (Pander et al 1992) but higher than previous estimates restricted to Australian Holstein and Jersey (Visscher and Goddard 1995).…”

Section: Discussionmentioning

confidence: 52%

A genome-wide association study of tick burden and milk composition in cattle

Turner¹,

Harrison

Bunch

et al. 2010

Anim. Prod. Sci.

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Abstract.To study the genetic basis of tick burden and milk production and their interrelationship, we collected a sample of 1961 cattle with multiple tick counts from northern Australia of which 973 had dairy production data in the Australian Dairy Herd Information Service database. We calculated heritabilities, genetic and phenotypic correlations for these traits and showed a negative relationship between tick counts and milk and milk component yield. Tests of polymorphisms of four genes associated with milk yield, ABCG2, DGAT1, GHR and PRLR, showed no statistically significant effect on tick burden but highly significant associations to milk component yield in these data and we confirmed separate effects for GHR and PRLR on bovine chromosome 20. To begin to identify some of the molecular genetic bases for these traits, we genotyped a sample of 189 of these cattle for 7397 single nucleotide polymorphisms in a genome-wide association study. Although the allele effects for adjusted milk fat and protein yield were highly correlated (r = 0.66), the correlations of allele effects of these milk component yields and tick burden were small (|r| 0.10). These results agree in general with the phenotypic correlations between tick counts and milk component yield and suggest that selection on markers for tick burden or milk component yield may have no undesirable effect on the other trait.

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“…Their review did not differentiate between livestock reared in temperate and tropical environments or under extensive and intensive production systems. Among ectoparasites in cattle, they reported significant heritabilities for nematode species (Stear et al, 1990;Mackinnon et al, 1991, both based on a subset of data from northern Australia reported herein); tick infestations (Stear et al, 1990;Minjauw and de Castro, 2000); and buffalo fly numbers (Stear et al, 1990). Among endoparasites, they reported significant heritabilities for resistance to trypanosomes (Murray et al, 1991) and also indicated the heritability of immune response traits could be substantial in pigs and dairy cattle.…”

Section: Component Traits Of Female Reproductionmentioning

confidence: 72%

Importance of adaptation and genotype × environment interactions in tropical beef breeding systems

Burrow

2012

Animal

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This paper examines the relative importance of productive and adaptive traits in beef breeding systems based on Bos taurus and tropically adapted breeds across temperate and (sub)tropical environments. In the (sub)tropics, differences that exist between breeds in temperate environments are masked by the effects of environmental stressors. Hence in tropical environments, breeds are best categorised into breed types to compare their performance across environments. Because of the presence of environmental stressors, there are more sources of genetic variation in tropical breeding programmes. It is therefore necessary to examine the genetic basis of productive and adaptive traits for breeding programmes in those environments. This paper reviews the heritabilities and genetic relationships between economically important productive and adaptive traits relevant to (sub)tropical breeding programmes. It is concluded that it is possible to simultaneously genetically improve productive and adaptive traits in tropically adapted breeds of beef cattle grazed in tropical environments without serious detrimental consequences for either adaptation or production. However, breed-specific parameters are required for genetic evaluations. The paper also reviews the magnitude of genotype 3 environment (G 3 E) interactions impacting on production and adaptation of cattle, where 'genotype' is defined as breed (within a crossbreeding system), sire within breed (in a within-breed selection programme) or associations between economically important traits and single nucleotide polymorphisms (SNPs -within a marker-assisted selection programme). It is concluded that re-ranking of breeds across environments is best managed by the use of the breed type(s) best suited to the particular production environment. Re-ranking of sires across environments is apparent in poorly adapted breed types across extreme tropical and temperate environments or where breeding animals are selected in a temperate environment for use in the (sub)tropics. However, G 3 E interactions are unlikely to be of major importance in tropically adapted beef cattle grazed in either temperate or (sub)tropical environments, although sex 3 environment interactions may provide new opportunities for differentially selecting to simultaneously improve steer performance in benign environments and female performance in harsher environments. Early evidence suggests that re-ranking of SNPs occurs across temperate and tropical environments, although their magnitude is still to be confirmed in well-designed experiments. The major limitation to genetic improvement of beef cattle over the next decade is likely to be a deficiency of large numbers of accurately recorded phenotypes for most productive and adaptive traits and, in particular, for difficult-to-measure adaptive traits such as resistance to disease and environmental stressors.

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Genetic variation and covariation for growth, parasite resistance and heat tolerance in tropical cattle

Cited by 115 publications

References 28 publications

Field study on nematode resistance in Nelore-breed cattle

Field study on nematode resistance in Nelore-breed cattle

A genome-wide association study of tick burden and milk composition in cattle

Importance of adaptation and genotype × environment interactions in tropical beef breeding systems

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