Wool quality in Gentile di Puglia sheep breed as measure of genetic integrity

Abstract

The Gentile di Pugliais a breed created in the 15th century by crossing Merino Spanish rams and “gentile” ewes reared in some areas of Southern Italy, mainly Apulia and Basilicata. The crisis of the wool industry, the poor quantity of milk, the inadequacy of Gentile di Pugliato be milked by machine and the passage from transhumant to permanent rearing caused a dramatic reduction of this population, which was largely crossed with other breeds and declined from about one million heads in the sixties to 5,000 at the present time. In order to save the ancient typical Gentile di Pugliabreed, the aim of this work was to estimate the “genetic integrity” of the remaining Gentile di Pugliapopulation by means of an analysis of wool quality measured through the diameter of the fibre and the homogeneity of the fleece. Our hypothesis was that the animals originated from outcrosses to other Merino derived breeds specialised for meat would show larger diameters of the fibres and a reduced homogeneity of the fleece. The research was carried out using Herd Book registered animals from 9 farms: 1 from Isernia, 2 from Campobasso and 6 from Foggia province. The statistical analysis on the diameter of the fibre was carried out on a dataset of 38,200 observations (200 records x 191 animals) divided in four classes (ultrafine, fine, croisè, ordinary). The high frequencies of ultrafine and fine fibre classes show that the quality of the wool is still good in the population. This consideration can be extended to all the farms involved in the study that could therefore be suitable in the conservation programs for this breed. The homogeneity of the fleece was also good in provid- ing further evidence of the genetic integrity of the population. Other analysis carried out on the quality of the wool in relation to the body size confirmed that the observed Gentile di Pugliais well representative of the ancient breed.

Full text

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ITAL.J.ANIM.SCI. VOL. 5, 371-376, 2006 371
Francesca Maria Sarti1, Emiliano Lasagna1, Francesco Panella1,
Gianvincenzo Lebboroni2, Carlo Renieri2
1Dipartimento di Biologia Vegetale e Biotecnologie Agroambientali e Zootecniche.
Università di Perugia, Italy
2Dipartimento di Scienze Veterinarie. Università di Camerino, Italy
Wool quality
in Gentile di Puglia sheep
breed as measure
of genetic integrity
ABSTRACT
The Gentile di Puglia is a breed created in the 15thcentury by crossing Merino Spanish rams and “gentile”
ewes reared in some areas of Southern Italy, mainly Apulia and Basilicata. The crisis of the wool industry,
the poor quantity of milk, the inadequacy of Gentile di Puglia to be milked by machine and the passage from
transhumant to permanent rearing caused a dramatic reduction of this population, which was largely crossed
with other breeds and declined from about one million heads in the sixties to 5,000 at the present time. In
order to save the ancient typical Gentile di Puglia breed, the aim of this work was to estimate the “genetic
integrity” of the remaining Gentile di Puglia population by means of an analysis of wool quality measured
through the diameter of the fibre and the homogeneity of the fleece. Our hypothesis was that the animals
originated from outcrosses to other Merino derived breeds specialised for meat would show larger diameters
of the fibres and a reduced homogeneity of the fleece. The research was carried out using Herd Book regis-
tered animals from 9 farms: 1 from Isernia, 2 from Campobasso and 6 from Foggia province. The statistical
analysis on the diameter of the fibre was carried out on a dataset of 38,200 observations (200 records x 191
animals) divided in four classes (ultrafine, fine, croisè, ordinary).
The high frequencies of ultrafine and fine fibre classes show that the quality of the wool is still good in the
population. This consideration can be extended to all the farms involved in the study that could therefore be
suitable in the conservation programs for this breed. The homogeneity of the fleece was also good in provid-
ing further evidence of the genetic integrity of the population. Other analysis carried out on the quality of the
wool in relation to the body size confirmed that the observed Gentile di Puglia is well representative of the
ancient breed.
Key Words: Gentile di Puglia, Wool quality, Genetic integrity.
RIASSUNTO
LA QUALITÀ DELLA LANA NELLA RAZZA OVINA GENTILE DI PUGLIA COME MISURA
DELLA SUA INTEGRITÀ GENETICA
La Gentile di Puglia è un razza sintetica creata nel XV secolo d.C. dall’incrocio tra arieti Merinos spagnoli e
pecore “gentili” allevate in alcune regione dell’Italia meridionale, particolarmente Puglia e Basilicata. La crisi
dell’industria laniera, la difficile adattabilità alla mungitura meccanica ed il passaggio dal tipico allevamento
Corresponding author: Prof. Francesca Maria Sarti. Dipartimento di Biologia Vegetale e Biotecnologie
Agroambientali e Zootecniche, sezione di Scienze Zootecniche. Università degli Studi di Perugia. Borgo XX
Giugno 74, 06121 Perugia, Italy - Tel. +39 075 5857123 - Fax: +39 075 5857122 - Email: zootea@unipg.it
Paper received May 8, 2006; accepted August 12, 2006

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SARTI et al.
372ITAL.J.ANIM.SCI. VOL. 5, 371-376, 2006
Introduction
The Gentile di Puglia is a breed created in the
15thcentury from a cross between Merino Spanish
rams and “Gentile” ewes reared in some areas of
Southern Italy, mainly Apulia and Basilicata
(Mascheroni, 1927). After the Second World War
the consistency of its population exceeded one mil-
lion heads.
Its dramatic reduction in population at the
beginning of the 60’s (AIA, 1961) was determined
by many causes. First of all there was the crisis of
the wool industry caused by the dramatic drop of
the market price due to the introduction of syn-
thetic fibres.Other reasons were the inadequacy of
Gentile di Puglia to be milked by machine deter-
mined by the udder morphology and the poor
quantity of milk, in addition to the transformation
of the production system from transhumance to
stationary due to changes in the social structure of
the human population (Liberale, 2000).
In order to maintain their market shares and,
therefore, their livelihood, Gentile di Puglia breed-
ers began the task of crossing their animals with
meat and milk sheep breeds according to their
short term production needs.This process resulted
in 41 different genetic types (Pollidori et al., 1986).
Animals from this pool were used to create a new
breed obtained by crosses to various other Merino
derived breeds (Ile de France, Berrichon du Cher,
Merinos Prècoce, Württemberg, ecc.).
A large number of animals derived from the
Gentile di Puglia converged into this new genetic
type named Merinizzata italiana contributing to a
further decline of the breed. At the present time,
with only 5,000 existing animals, the Gentile di
Puglia population is considered endangered
according to E U parameters (Reg. E C No
445/2002).
It seems appropriate, in such a situation, to
reassess the typical products of the breed and to
introduce safeguards to avoid its extinction.
Several studies were therefore carried out with
the aim to define number, present geographic dis-
tribution (Panella et al., 2003) and meat quality
(Sarti et al., 2001) of the Gentile di Puglia.
The aim of the present study was to estimate
the quality of the breed wool by measuring the
transumante a quello stanziale ne hanno causato una drastica riduzione da circa un milione di capi negli anni
’60 agli attuali 5.000.
Per salvaguardare il tipo genetico originale della Gentile di Puglia, si è voluta stimare “l’integrità genetica”
della popolazione residua tramite l’analisi della qualità della lana misurata attraverso il diametro del filamen-
to lanoso e l’omogeneità del vello.
L’ipotesi di partenza è che gli animali originatisi dall’incrocio con altre razze derivate Merinos specializzate
per la produzione carne, dovrebbero mostrare maggiori diametri del filamento lanoso ed una minore omoge-
neità del vello.
La ricerca è stata condotta in nove aziende tutte con soggetti iscritti al Libro genealogico: 1 nella provincia
di Isernia, 2 in quella di Campobasso e 6 in provincia di Foggia. Per l’analisi statistica del diametro della fibra
è stato utilizzato un dataset costituito da 38.200 osservazioni (200 letture del diametro*191 animali) suddi-
vise in quattro classi di finezza (lana ultrafine, fine, croisè ed ordinaria).
L’elevata frequenza delle fibre nelle prime due classi dimostra che nella popolazione residua la qualità della
lana è ancora buona; la stessa considerazione può essere estesa anche a tutte le aziende studiate che per-
ciò potrebbero fornire un utile strumento per i programmi di conservazione attuati per questa razza. Anche
l’omogeneità del vello ha fornito un’ulteriore prova dell’ “integrità genetica” della popolazione esaminata.
Altre analisi statistiche condotte per stimare la qualità della lana in relazione alla taglia dell’animale hanno
confermato che la popolazione residua di Gentile di Puglia costituisce un campione rappresentativo della
razza originaria.
Parole chiave: Gentile di Puglia, Qualità della lana, Integrità genetica.

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GENTILE DI PUGLIA SAFEGUARD
ITAL.J.ANIM.SCI. VOL. 5, 371-376, 2006373
diameter of the fibre and its homogeneity in the
fleece and to use these traits to evaluate if only
ancient animals are in the Gentile di Puglia popu-
lation. It is in fact assumed that only purebred
animals produce wool of a certain quality (fibre
diameter ≤ 24 µm), while out crossed animals pro-
duce fibres with larger diameters and therefore
lesser quality wool (ASSONAPA, 1997).
Material and methods
The research was carried out on 9 farms: 1
from Isernia, 2 from Campobasso and 6 from
Foggia province.All animals were registered in the
National Herd Book.
A random sample of 191 animals (28 males
and 163 females) of different ages was extracted
from this population; this number was equal to
10% of the total size of each observed farm (Table
1). The wool samples, taken in February 2002,
were shared from the flank of each animal, put in
plastic bags and analyzed at the Department of
Veterinary Science of Camerino. Fibre diameter
was measured with an ASTM Standards D 6500 –
00. This is the official method used for fineness
and CV (coefficients of variability) fibre analysis
and requires the measurement of 200 diameters
using Optical Fiber Diameter Analyser. The
medullated and kemp fibres were analysed with
the ASTM Standards D 2968 – 95.
Wool grease was removed with ether oil, and
then the sample was oven dried (30’ at 100°).
Finally, the samples were processed for the micro-
scope preparation.
For the statistical analysis the fibre diameter
was divided into four classes (ultrafine:13-16 µm;
fine: 17-24 µm; croisè: 25-40 µm; ordinary: >40 µm)
according to Wuliji et al. (1999) and other commer-
cial classifications (Helen, 2005).
Frequencies of fibre diameter and main statis-
tical parameters such as mean, standard devia-
tion, maximum and minimum values, coefficient of
variability, were estimated on a dataset of 38200
observations (200 records x 191 animals).
The significance of environmental factors on
fibre diameter was tested according to the follow-
ing mixed linear model:
yijklm=µ+Fi+F(N)ij+Ak+Sl+eijklm
where:
yijklm: fibre diameter;
Table 1. The animal population sample.
FarmProvinceTotal (n.)Male (n.) Female (n.)Age (years)
xSD
1.66
2.00
0.94
1.90
2.13
1.66
2.50
1.95
2.57
1
2
3
4
5
6
7
8
9
Total
IS
CB
CB
FG
FG
FG
FG
FG
FG
7
7
5
2
2
1
3
5
8
3
2
2
28
5
5
4
13
42
27
25
22
20
163
4.00
4.37
3.66
4.87
5.73
5.12
4.59
4.67
4.04
16
47
35
28
24
22
191
IS: Isernia, CB: Campobasso, FG: Foggia (Italy).

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SARTI et al.
374ITAL.J.ANIM.SCI. VOL. 5, 371-376, 2006
µ: general mean;
Fi :effect of farm (i = 1,…,9);
F(N)ij:random effect of animal nested within farm;
Ak : effect of age in years (k = 1,…,9);
Sl : effect of sex (l = 1, 2);
eijklm: experimental error.
The interactions between the factors were not
significant and therefore were excluded from the
statistical model.
To measure fleece homogeneity, the CV calcu-
lated from fibre diameter within each animal were
divided into three classes (1: 0.10-0.14; 2: 0.15-
0.19; 3: ≥ 0.20) and the respective frequencies were
obtained.
The outcrossing of the Gentile di Puglia to
other meat breeds is expected to determine a wors-
ening of fleece quality but also an increase in body
size. Therefore the CV classes of fleece were used
as a variability factor to estimate the “genetic pol-
lution”. In addition, the relationship between the
biometric measurements reported on the Gentile
di Puglia standard (ASSONAPA, 1997) and aver-
age fibre diameter of each animal were also esti-
mated to verify whether the quality of the wool
was associated to the body size; the following lin-
ear model was used:
yijklm=µ+CVi+Fj+Ak+Sl+B(D)m+eijklm
where:
yijklm: biometric measurements (biometric mea-
surements reported on the Gentile di Puglia stan-
dard: weight, chest girth, wither height, sacrum
height, chest height, rump width, trunk length);
µ: general mean;
CVi: effect of classes of coefficients of variabili-
ty of the fleece (i = 1,…,3);
Fj: effect of farm (i = 1,…,9);
Ak: effect of age in years (k = 1,…,9);
Sl: effect of sex (l = 1, 2);
B(D)m : partial regression coefficient of depen-
dent variable (biometric measurement) on the
covariate D (fibre diameter);
eijklm: experimental error.
The interactions between the factors were not
significant and therefore were excluded from the
statistical model.
Statistical analysis was performed using SAS
software (SAS, 2000).
R esults and discussion
The frequencies of the four classes of wool
fibre diameter were 17.42, 68.34, 14.23, 0.01
Table 2. Significance (Pr> F) of the effects
on the fibre diameter.
Farm AgeSexF(N)
*** ****** ***
SE
R2
3.76
0.21
***: P<0.001
Table 3. Frequencies (%) of CV classes by farm.
Farm
Class123456789
1
2
3
38.79
46.08
15.13
54.26
31.49
14.25
26.11
37.45
36.44
23.53
58.82
17.65
29.41
52.94
17.65
8.82
58.82
32.35
14.29
50.00
35.71
29.17
70.83
0.00
0.00
65.00
35.00

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GENTILE DI PUGLIA SAFEGUARD
ITAL.J.ANIM.SCI. VOL. 5, 371-376, 2006 375
respectively for classes 1, 2, 3 and 4 and show
that the quality of the wool is still high in almost
the whole of the Gentile di Puglia population.
There are two different considerations to make
about this result: the population is barely pollut-
ed by the meat breeds used by breeders in the
area and therefore is representative of the
ancient breed; the good quality of the wool lets us
envisage a possible use in the niche of typical
products giving a possible chance to the econom-
ic competitiveness of this breed.
All the tested fixed factors had a significant
effect (Table 2) on the fibre diameter, the estimat-
ed means showed that the wool diameter of males
(19.9) was lower than that of females (20.4) con-
firming a better quality of rams fibres.
Mean fibre diameters per farm ranged from
21.6 µm (6 years) to 19.23 µm (2 years) and showed
a better quality wool in the younger animals.
The wool diameters resulted very low in all
farms ranging from 21.71 (farm 3) to 18.1 (farm 2).
This is an encouraging result that shows how the
population is well representative of the ancient
breed and could therefore be suitable for use in
conservation programmes.
The genetic integrity of the Gentile di Puglia
population was also estimated using fleece
homogeneity, which was measured through the
wool diameter coefficient of variability (CV) of
each animal.
The CV had the following total frequencies
17.83, 58.6, and 23.57, respectively, for classes 1, 2
and 3 showing a relatively good homogeneity in
the population. The CV frequencies analysed for
each farm (Table 3) showed high quality levels in
all of them. In fact the percentage of CV values
smaller than 0.20 ranged from 100% in farm 8 to
64.29% in farm 7.This result seems to confirm the
suitability of the studied flocks for conservation
programmes.
In the studied flocks animals with body mea-
sures larger than the Gentile di Puglia standards
were observed (i.e. sheep weight is 43.0 kg in the
standard and 47.0 kg in the sample); this could be
due either to the outcrossing with larger breeds
and therefore to genetic pollution or to an
improvement of the flock management and feed-
ing. In order to answer this question, the relation-
ship between wool diameter and body size was cal-
culated according to the model already referenced
in the material and methods section. A positive
significant relationship was expected if the first
hypothesis were true, on the contrary the statisti-
cal analysis showed that the covariate “diameter
of wool fibre” has negligible significance levels
(Table 4) and therefore it is correct to exclude sig-
Table 4. Significance (Pr> F) of the coefficients of variability (CV) of the fleece on the
biometric measures.
Biometric
measures
FarmAgeSex Fibre
diameter
Class
of CV
SER2
Weight
Chest girth
Wither height
Sacrum height
Chest height
Rump width
Trunk length
***
***
***
0.004
0.004
***
***
***
***
0.02
0.33
***
0.02
0.005
***
***
***
***
***
***
***
0.86
0.64
0.62
0.94
0.77
0.63
0.46
0.87
0.51
0.57
0.75
0.56
0.23
0.48
6.9
6.3
2.8
3.6
2.0
1.8
2.8
0.73
0.62
0.56
0.43
0.50
0.49
0.61
***: P< 0.001