Tracking the Origin of a Rabbit Haemorrhagic Virus 2 Outbreak in a Wild Rabbit Breeding Centre in Portugal; Epidemiological and Genetic Investigation

As key prey, the wild rabbit downsize constitutes a major drawback on the endangered Iberian lynx (Lynx pardinus) re-introduction in the Iberia. Several captive breeding units mostly located in Alentejo, endeavour the wild rabbit repopulation of depleted areas assigned for the lynx re-introduction. Here we report an RHDV2 outbreak that occurred in early 2016 in a wild rabbit captive breeding unit located in Barrancos municipality. The estimated mortality rate between March and April 2016 was approximately 8.67%. Anatomopathologic examination was carried out for 13 victimized rabbits. Molecular characterization was based on the complete vp60 capsid gene. The 13 rabbit carcasses investigated showed typical macroscopic RHD lesions testing positive to RHDV2- RNA. Comparison of the vp60 nucleotide sequences obtained from two specimens with others publically available disclosed similarities below 98.22% with RHDV2 strains originated in the Iberia and Azores and revealed that the two identical strains from Barrancos-2016 contain six unique single synonymous nucleotide polymorphisms. In the phylogenetic analysis performed, the Barrancos-2016 strains clustered apart from other known strains, meaning they may represent new evolutionary RHDV2 lineages. No clear epidemiological link could be traced for this outbreak where the mortalities were lower compared with previous years. Yet, network analysis suggested a possible connection between the missing intermediates from which the strains from Barrancos 2013, 2014 and 2016 have derived. It is therefore possible that RHDV2 has circulated endemically in the region since 2012, with periodic epizootic occurrences. Still, six years after its emergence in wild rabbits, RHDV2 continues to pose difficulties to the establishment of natural wild rabbit populations that are crucial for the self-sustainability of the local ecosystems.

Contributo para a caracterização das raças serpentinas e charnequeira

Esta dissertação retoma um estudo com 49 cabras e 45 cabritos da raça Serpentina, 24 cabras e 28 cabritos da raça Charnequeira, exploradas em regime extensivo. Pretende ser um contributo para a caracterização destas raças. Com este objectivo calculou-se a fertilidade que foi de 92% nas duas raças e a prolificidade foi de 160% (62,5% partos duplos) na Serpentina e de 141% (57,1% partos duplos) na Charnequeira. A mortalidade dos cabritos, do nascimento até ao desmame, foi de 15,7%, na Serpentina e de 6,6%, na Chamequeira. Os pesos das cobrições ao parto, na Serpentina aumentaram 17% e 13,6% na Chamequeira, apresentando variações significativas na raça, mas não entre raças. Os cabritos de partos simples obtiveram maiores ganhos médios diários do nascimento ao desmame. Não houve variações significativas nos pesos entre machos e fêmeas. Analisaram-se 24 carcaças de cabritos, machos inteiros. O Rendimento Corrigido foi de 52% para as duas e a relação Músculo/Osso de 2,13 (Charnequeira) e 2,12 (Serpentina). O Índice Compacidade para a Charnequeira foi de 11,78 e 11,29 para a Serpentina, evidenciando esta melhor conformação. Definiram-se os seguintes cortes nas carcaças: I-Pá; II-Perna; III- Costela+Sela; IV-Aba; V-Pescoço. Analisou-se o músculo quanto à gordura, proteína, cálcio e fósforo. ABSTRACT: This dissertation retrieves a study involving 49 goats and 45 kids of Serpentina breed, 24 goats and 28 kids of Chamequeira breed exploited in an extensive management. It is intended as a contribution to the characterization of these breeds. To this end, various reproductive parameters were calculated. The fertility stood at 92% in both breeds and the prolificacy in the breed Serpentina was 160% (62.5% in twin births) and in the breed of Chamequeira was 141% (57.1% in twin births). We noted a mortality rate in kids from birth to weaning higher in the Serpentina breed (15.7%), while the Chamequeira breed recorded 6.6%. The evolution of the weights during the mating period to childbirth, increasing 17% in the Serpentina breed and 13.6% in Chamequeira breed. We noted significant variations in each breed, but not between each other. The kids resulting of simple birth had higher average daily weight gain from birth to weaning. We did not note significant variations of weight between males and females. We analysed the carcasses of 24 male kids. The corrected yield was 52% for both breeds and the muscle-bone ratio was 2,13 (Chamequeira) and 2,12 (Serpentina). The compactness index for the Chamequeira breed was 11.78 and 11.29 for the Serpentina breed, showing Serpentina breed had better conformation. We proposed the following cuts in the carcass: I-Shovel, II Leg, III- Rib +Sela, IV-Aba and V-Neck. We also analysed the muscle according to their fat, protein, calcium and phosphorus, aiming to show the dietary interest of this muscle.