**5.1.2 Animals**

464 Health Management – Different Approaches and Solutions

As to TBD, the response is known to be under multi-factorial regulation (Horin, 1998; Aguilar-Delfin et al., 2001). As highlighted in the above section 4, the phenomenon of tolerance is a broad-based one and possibly not unrelated to the erythropoietic system in different sheep breeds or to the haemoglobin genetic systems (Pieragostini et al., 2003;

Anyway, the success of selection for disease resistance is dependent on correctly identifying the disease agent and the phenotype for disease resistance. For example, as to TBP in small ruminants, there are several reports concerning the presence of *Babesia, Theileria,* and *Anaplasma* species infecting sheep and goats in many countries world-wide but, in many regions of the Old and the New World, the identity of the tick-borne disease agents of sheep and goats and of their vector ticks is uncertain. But perhaps, the biggest challenge of selecting for disease resistance is to accurately identify the phenotype for disease resistance and/or to have reliable genetic markers with high predictive values for a disease phenotype. Phenotypic variability induced by parasites is a matter of fact, as impressively exemplified by the high number of haemoglobinopathies in human populations living in malaria-

Recalling Feynman's1 saying that nature repeats itself at every scale, we suggested that the unusual haemoglobin polymorphism recorded in Apulian native sheep breeds and the related functional effects might have an adaptive significance, also being somehow related to the selective pressure of tick borne parasites (TBP) (Pieragostini et al., 1994; Pieragostini et al., 2003; Pieragostini et al., 2006). Based on these considerations, we aimed to define the phenotype of the tick borne diseases in different sheep breeds starting from the one caused by *A. ovis*, the most common parasite in our area as confirmed by a small survey on sheep TBP performed in 10 farms (throughout Apulia) on 240 individuals. *A. ovis* was identified in 58% of samples, followed by *T. ovis* (5.8%) and *T. annulata* (4.5%). *Theileria* spp*.* were present in mixed infections with *A. ovis, B. ovis* (0.9 %) or *Babesia* spp. (0.9 %). In particular the presence of *A. ovis* was confirmed by specific polymerase chain reactions (PCRs) for *Anaplasma* spp. (Stuen et al., 2003) and *A. ovis* (de la Fuente et al., 2005; de la Fuente et al., 2007). Then PCRs followed by reverse line blot hybridization of the amplified 18SrRNA gene from *Theileria* and *Babesia* species, was used to detect specific probes for *Theileria/Babesia catch all, Theileria sp1 china, Theileria sp2 chinal, T. buffely, T. annulata, T. velifera, T. taurotragi, T. mutans, T. lestoquardi, T. ovis, B. bovis, B. bigemina, B. crassa, B. motasi, B. ovis, B. major, B. divergens, T.* 

Pieragostini et al., 2006).

2009

genotypes

Table 7. Experimental design.

the Nobel Prize in Physics in 1965.

endemic areas (Evans & Wellems, 2002).

*hirci, B. sp1 (Turchey), B. sp2 (Lintan*) (Schnittger et al., 2004).

Infection of 8 Suffolk and 8 Comisana characterized by normal alpha globin gene arrangements and different beta

**Year Step 1 Year Step 2** 

2009 Search for carriers 2010 Search for carriers 2009 Splenectomization 2010 Splenectomization

2010

1 Richard Phillips Feynman (May 11, 1918 – February 15, 1988) was an American physicist who received

Infection of 18 Altamurana characterized by different alpha globin gene arrangements

Selected animals 7/8 months of age were involved in this study. Lambs less than six months of age were purchased and housed at the Medical Clinics of the Faculty of Veterinary Medicine of the University of Bary. Upon arrival at the Faculty of Veterinary Medicine, the animals were weighed and faecal samples were obtained to establish their worm burdens. Feet were checked for foot rot. The animals were dewormed with a broad spectrum anthelmintic. All of them were then housed in a tick proof isolation unit. In particular, in 2009 the lambs were selected based on different breed and equally divided between Suffolk and Comisana.

Fig. 5. Alpha-globin gene haplotypes detected so far in sheep, namely: haplotypes 1, 2 and 3 are normally duplicated (NH); haplotypes 4, 5 and 6 show extranumeral alpha gene arrangements (EH); particularly haplotypes 4 and 5 are triplicated while haplotype 6 is quadruplicated.

All the lambs were characterized by a normal duplicate alpha gene arrangement (Fig. 5) and most of them by homozigosity at the beta globin loci. Owing to high frequency of HBBA gene in the Suffolk breed, three out of the eight Suffolk lambs were HBBAB heterozygotes. In 2010 eighteen Altamurana lambs less than six months of age, housed and treated as above described, were selected based on different alpha globin genetic arrangements. Nine lambs were homozygotes for the normal duplicate alpha gene haplotype (NH), the others carrying an extra-numeral alpha haplotype (EH) (Fig.5); most of the 18 lambs were homozygotes for the HBBB allele at the beta globin loci.

Tolerance to Tick-Borne Diseases in Sheep:

**Breed Dose of** 

Suffolk

Comisana

Altamurana

capital letters: P <0.01; small letters: P<0.05.

Highlights of a Twenty-Year Experience in a Mediterranean Environment 467

The haematological patterns were then analyzed in detail comparing the intra breed variations between the different physiopathological moments – normal health status (time 0=T0), acute phase (time 1=T1 ) recovery phase (time 2=T2 ) - and the between breed variations intra physiopathological moments (table 9). Finally, clinical parameters, such as incubation time (I.T) after infection, temperature peak (T.P.), percentage decrease in haematocrit ( HCT), percentage decrease in haemoglobin content ( Hb) expressed as gr Hb/dl blood, percentage

**intervention Morbidity Expected** 

**Mortality** 

**infection Symptoms Need for therapeutic** 

decrease in red blood cells ( RBC) were evaluated for each breed (Table 10).

**Breed Parameter T0 T1 T2** Mean SD Mean SD Mean SD

> PCV (g/dl) 31.9 ± 2.8 a 12.7 ± 2.7 A 23.9 ± 2.3 a Hb (g/dl) 11.5 ± 1.0 a 4.7 ± 0.7 A 7.7 ± 0.7 a RBC (106/l) 12.5 ± 1.2 A 4.5 ± 0.8 a 7.2 ± 1.0 MCV (fl) 25.0 ± 1.0 A 32.3 ± 1.6 A 33.3 ± 3.0 A MCH (pg) 9.2 ± 0.3 B 10.5 ± 0.6 A 10.7 ± 0.6 A MCHC (g/dl) 36.8 ± 1.0 A 32.5 ± 1.2 32.3 ± 0.8 WBC (103/l) 8.6 ± 1.1 10.9 ± 2.4 0.3 ± 1.1 a

> PCV (g/dl) 35.0 ± 2.4 b 11.3 ± 2.7 A 26.2 ± 1.7 b Hb (g/dl) 12.6 ± 1.0 b 4.7 ± 0.5 A 8.6 ± 0.7 b RBC (106/l) 11.9 ± 1.3 A 5.1 ± 0.8 a 6.9 ± 0.7 MCV (fl) 29.7 ± 2.3 B 29.1 ± 3.2 B 38.4 ± 3.2 B MCH (pg) 10.7 ± 0.7 A 9.4 ± 1.1 B 12.5 ± 0.9 B MCHC (g/dl) 35.9 ± 1.3 A 32.1 ± 0.4 32.5 ± 1.0 WBC (103/l) 10.1 ± 2.7 7.5 ± 1.4 10.4 ± 2.9 b

> PCV(g/dl) 31.2 ± 3.2 a 21.6 ± 3.1 B 25.8 ± 2.4 b Hb (g/dl) 0.4 ± 1.0 C 7.1 ± 1.0 B 8.2 ± 0.8 b RBC (106/l) 9.4 ± 1.0 B 6.2 ± 1.0 b 7.1 ± 0.8 MCV (fl) 33.2 ± 1.9 C 34.7 ± 1.7 C 36.6 ± 2.0 B MCH (pg) 10.6 ± 0.5 A 11.4 ± 0.5 C 11.6 ± 0.5 B MCHC (g/dl) 31.7 ± 0.7 B 32.8 ± 0.9 31.9 ± 1.0 b WBC (103/l) 10.1 ± 2.6 9.6 ± 2.0 10.1 ± 1.4 B

Table 9. Haematological parameters assessed for the three analyzed breeds, namely normal health status before infection (time 0=T0), during the acute phase (time 1=T1 ) and during the recovery phase (time 2=T2 ). Means within columns with different letters significantly differ:

Suffolk 36% very severe 7 out of 8 subjects 100% 87.5% Comisana 36% severe 1 out of 8 subjects 100% 12.5% Altamurana 56% mild none 100% 0% Table 8. Overview of responses to anaplasmosis in the three analyzed breeds.
