Is there gene*c resistance of Nellore ca2le to both *cks and gastro-intes*nal parasites? Fabio Luiz Buranelo Toral Department of Animal Science / UFMG Andrea Wilson s group GeneAcs and Genomics Division / Roslin 13 th MeeAng Edinburgh Alliance for Complex Trait GeneAcs Royal Society of Edinburgh
Brazilian ca2le 210-220 M heads ~ 80% beef caqle 168 176 M heads ~ 70% Zebu breeds ~ 75% Nellore or crossbred 88 92 M Nellore or crossbred
Nellore is widely distributed over Brazil Pontes e Lacerda, MT Carlos Chagas, MG
Nellore is exposed to great seasonal varia*on Nelore Lemgruber Nelore IRCA
Animals should stay healthy along the year To reproduce To growth Daniel Resende ABS Pecplan
To achieve sustainability in livestock produc*on Animal breeding Sanity NutriAon Animal welfare Etc
The annual cost with an*parasi*c for ruminants in Brazil 2016 R$852.5M 198.2M Adapted from SINDAN (2017).
Animal breeding is about to explore differences between and within breeds Crossbreeding Selec:on
Significant difference between gene*c groups for *ck counts Adapted from Ibelli et al. (2012).
Non significant difference between gene*c groups for number of eggs per gram Oliveira et al. (2013).
Non significant effect of gastrointes*nal nematodes on Nellore growth Mean number of nematodes in the resistant (n=10) and suscep:ble (n=10) groups of Nellore young bulls naturally infected by gastrointes:nal nematodes Nematodes Resistant Suscep:ble Significance Body weight of the resistant (n=10) and suscep:ble (n=10) groups of Nellore young bulls, naturally infected with gastrointes:nal nematodes Haemonchus spp. 156 1,272 <0.01 Cooperia spp. 1,500 4,807 <0.05 Oesophagostomum spp. 100 174 Trichuris spp. 22 22 Total 1,778 6,275 <0.05 Adapted from Bricarello et al. (2007).
Non significant effect of *ck and gastrointes*nal nematodes on Nellore growth Group N Mean (g/day) SE (g/day) Tick High 533 557.37 3.24 Low 568 552.17 3.12 Nematodes High 520 553.28 3.32 Low 581 555.84 3.12 Barbosa (2016).
Do *cks and nematodes affect Nellore performance? Yes. So, why the researchers didn t find this? No. So, why the farmers spend so much money on parasite treatments?
Increase food safety in beef GeneAc variaaon for resistance to parasites (Acks, nematodes and Eimeria spp.) SelecAon as a complementary tool in parasite control programs Reduce the ualizaaon of chemicals in beef caqle producaon systems
Data recording in a Nellore seedstock farm Young bulls on pasture performance tests (294 d) Groups of 30-35 animals (8 groups/year) 70 d of adaptaaon EvaluaAons (weight and parasite counts) every 56 d, unal 550 days of age Up to 5 measurements / animal From April 2011 to May 2017 7,871 Ack counts (1,713 animals, 130 sires) 7,292 nematodes and Eimeria spp. counts (1,712 animals, 130 sires) 5,920 animals in the pedigree
Distribu*ons of parasite counts are neither Gaussian nor Poisson
FiPng of Zero Inflated Poisson distribu*ons Tick count in dairy cows (Silva et al., 2011) Tick count in sheep (Sae-Lim et al., 2017) Faecal egg count in sheep (Wang et al., 2017) Number of masaas cases in dairy cows (Rodriges-MoQa et al., 2007)
FiPng of ZIP distribu*ons
The interpreta*ons of gene*c parameters are not trivial under ZIP models There is no obviously useful definiaon of heritability (Rodrigues- MoQa et al., 2007). We assessed the importance of addiave geneac differences between animals fijng models without and with addiave geneac effect. We assessed the relaaonship between phenotypes and breeding values (under liability scale).
Low phenotypic correla*on between parasite counts 0.11 (0.09, 0.13) 0.04 (0.02, 0.06) 0.14 (0.11, 0.16)
Gene*c varia*on was found to be important Deviance informaaon criterion according to staasacal models Addi:ve gene:c effect Parasite Without With Tick 42,532 42,515 Nematodes 38,545 38,527 Eimeria spp. 33,366 33,359
Gene*c varia*on was found to be important Tick Nematode Eimeria spp. Effect Mean Median S.D. Mean Median S.D. Mean Median S.D. Animal (A) 0.140 0.137 0.023 0.289 0.289 0.012 0.187 0.176 0.047 Permanent environment (Pe) 0.211 0.209 0.018 0.238 0.238 0.009 0.600 0.596 0.046 Group (Gr) 1.037 1.030 0.085 0.416 0.412 0.038 4.658 4.615 0.046 A / (A+Pe+Gr) 0.101 0.306 0.034 (A+Pe) / (A+Pe+Gr) 0.253 0.559 0.145
Correla*ons between breeding values are low to moderate 0.30 (0.27, 0.32) 0.01 (-0.02, 0.03) -0.07 (-0.09, -0.04)
Moderate rela*onships between breeding values and phenotypes Tick Nematode Eimeria spp. 0.59 (0.56, 0.62) 0.77 (0.75, 0.79) 0.41 (0.37, 0.45)
Animals with the best breeding values have smaller parasite counts
Animals with the best breeding values have smaller parasite counts
Animals with the best breeding values have smaller parasite counts
Conclusions There is geneac resistance of Nellore caqle to both Acks and gastrointesanal parasites Acks. Tick and nematodes counts may be geneacally correlated. Breeding values under liability scales are useful for selecaon of resistant animals.
Next steps GWAS for resistance to Acks and gastro-intesanal parasites. To fit models accounang for infecavity. Is there geneac correlaaon between resistance and infecavity?
Acknowledge UFMG CNPq FAPEMIG CAPES Mundo Novo Ranch Ronaldo Leite Eduardo Cardoso Daniel Goncalves Andrea Wilson Osvaldo Anacleto
Acknowledge Juan Pablo Botero Carrera Tiago Luciano Passafaro Livia Loiola dos Santos Dalinne dos Santos Fernanda Raidan Muller Gomes Glausen Lima Thank you! Adriane Barbosa Larissa Kretli Mariana Mamedes Andresa Melo Gabriela Gouveia Virgínia Ribeiro Luiza Abreu Etc