VETERINARSKI ARHIV 82 (4), 351-358, 2012
.
Reproductive performance of boer goats in a moderate climate zone
Dražen Đuričić1, Juraj Grizelj2, Tomislav Dobranić2, Ivica Harapin3,
Silvijo Vince2, Predrag Kočila4, Ivan Folnožić2, Marija Lipar5,
Gordana Gregurić Gračner6, and Marko Samardžija2*
Veterinary Practice d.o.o. Đurđevac, Đurđevac, Croatia
1
2
Reproduction and Obstetrics Clinic, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia
3
Clinic of Internal Diseases, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia
Food Animal Factory, Čakovec, Croatia
4
5
Clinic for Surgery, Ortopaedics and Ophtalmology, Faculty of Veterinary Medicine, University of Zagreb,
Zagreb, Croatia
6
Department for Biology, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia
________________________________________________________________________________________
ĐURIČIĆ, D., J. GRIZELJ, T. DOBRANIĆ, I. HARAPIN, S. VINCE, P. KOČILA,
I. FOLNOŽIĆ, M. LIPAR, G. GREGURIĆ GRAČNER, M. SAMARDŽIJA:
Reproductive performance of boer goats in a moderate climate zone. Vet. arhiv 82,
351-358, 2012.
ABSTRACT
The objective of this study was to determine the reproductive performance in Boer goats under semiintensive management in north-western Croatia over three consecutive years. Sixty Boer does, aged 2 to 6
years, were divided into three groups. A total of 1.80 kids were born per doe (435 newborn in 242 pregnancies).
Boer goat fertility was 93.44%. Does with single kids accounted for 22.53% (n = 98), with twins 49.20% (n
= 107), triplets 18.62% (n = 27), quadruplets 7.35% (n = 8) and quintuplets 2.29% (n = 2). The average birth
weight of Boer kids was 3.48 ± 0.04 kg (1.70 kg to 5.4 kg). The birth weight of goat kids in pluriparous Boer
does was significantly (P<0.05) higher in comparison to kids in primiparous does by gender. The birth weight
of Boer male goat kids was significantly (P<0.05) higher than female Boer kids. There was no impact from
goat age, number of kiddings and birth weight. More than 76% of Boer does delivered in the winter and spring.
It is supposed that after transferring from the southern to the northern hemisphere, Boer goats have gradually
acclimated to a new seasonality.
Key words: birth weight, boer goat, goat kids gender, reproductive performance
________________________________________________________________________________________
*Corresponding author:
Prof. dr. sc. Marko Samardžija, Clinic for Reproduction and Obstetrics, Faculty of Veterinary Medicine, Zagreb, Heinzelova 55,
10000 Zagreb, Croatia, Phone: +385 1 2390 321; Fax: +385 1 2441 390; E-mail: smarko@vef.hr
ISSN 0372-5480
Printed in Croatia
351
D. Đuričić et al.: Reproductive performance of boer goats in a moderate climate zone
Introduction
Sheep and goats are seasonal breeders (seasonally polyoestrous) in the moderate
climate region, with the breeding season becoming longer towards the equator (ZARROUK
et al., 2001). The length of the breeding season is primarily the result of genetics and
environmental interactions (BODIN et al., 1999; FABRE-NYS, 2000). Different factors,
such as photoperiod, temperature, nutrition, breed and male effect, regulate physiological
response. Seasonality is controlled by the number of dark hours the animal is exposed to
(KARSCH et al., 1984; MALPAUX et al., 1994). During the night, the pituitary gland releases
melatonin (CHEMINEAU and DELGADILLO, 1994; FABRE-NYS, 2000), which provides
stimulation of the hypothalamus-hypophysis-ovarium axis. The natural breeding season
of dairy goat breeds in the northern hemisphere is usually restricted to the period between
September and November (beginning in late August and ending in late December to mid
January) with a clear anoestrous period from February to the end of May (SHELTON,
1978; CORTEEL, 1977; CHEMINEAU et al., 1992). Tropical breeds of goat are thought to
be aseasonally polyoestrus and can breed throughout the year (DELGADILLO, 2004). In
tropical regions, the photoperiod is less important than temperature, rainfall, vegetation
and herbal growth (dry and rainy seasons) (HAMBOLU and OJO, 1985). There is no impact
of air temperature or rainfall on the reproductive performance of Boer goats in northwestern Croatia (DJURICIC et al., 2010). Reproductive performance in goats is influenced
by the age of goats at first kidding, kidding interval, litter size, and birth kid body weight
and weaning weight (SONG et al., 2006). Reproductive performance is the productivity of
the animal, herd or flock in terms of offspring produced, and can be expressed in many
ways (prolificacy, fertility, fecundity, interkidding period and days open). Prolificacy,
fertility and fecundity in small ruminants varies by breed, season, age, nutritional status,
health, breeding management and farm supplies. The interkidding period is the period
(in days) between two consecutive parturitions. The average interkidding period in goats
in the northern hemisphere is about one year (from one kidding season to the next). The
service period is the interval from partus to conception. Boer goats evolved in Southern
Africa from indigenous African (and introduced European) goats (CASEY and VAN
NIERKERK, 1988). This meat breed of goats has been described as having the ability of
rapid acclimation and adaptation, low water turnover rates and low parasite infestation
(ERASMUS, 2000; SHELTON, 1978), and therefore improved Boer goats are widespread
throughout the world (MALAN, 2000). In southern Africa, the Boer goat is aseasonally
polyoestrous, with the peak of sexual activity in autumn. The period of lowest sexual
activity is usually during late spring and mid-summer (GREYLING, 2000; GREYLING and
VAN DER NEST, 1990). Kiddings began in April and May and were very rapid during the
period of vegetation growth (GREYLING and VAN DER NEST, 1990). The mean duration
of the service period in Boer goats was recorded at 62.0 ± 20.2 days in South Africa
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D. Đuričić et al.: Reproductive performance of boer goats in a moderate climate zone
(GREYLING, 2000), as compared to 108.22 ± 4.42 days (values between 64.4 ± 8.30 days
in autumn and 151.3 ± 2.66 days in winter) in northwest Croatia. The mean interkidding
period in Boer goats was the longest in winter (309.70 ± 2.66 days) and the shortest in
autumn (229.73 ± 8.29 days) (ĐURIČIĆ et al., 2009a). The average gestation length of
Boer does in north-western Croatia was 148.87 ± 0.86 days, i.e. from 143 to 159 days
(ĐURIČIĆ et al., 2009b).
Materials and methods
In this study, 60 Boer goats, aged from 2 to 6 years, were investigated. Goats were
kept in a semi-intensive environment in north-western Croatia. Animals were kept at
pasture, which primarily provided area for exercise, with access to stables during the
night. Does were divided into three groups, and each group was paired with different
bucks every year.
Feed concentrate (450 g) was provided twice daily at the same time (40% corn, 17%
soybean, 16% oats, 16% barley, 8% wheat flour and 3% mineral and vitamin supplement
for goats). According to standard farming practice, the animals had free access to good
quality meadow hay (about 1.8 kg per doe daily) and drinking water. All does had equal
opportunity to kid in all seasons. All goats were kept together with their kids from kidding
until weaning (about 3-4 months of age). Boer kids suckled ad libitum and after 1-1.5
months were fed with concentrate and hay. Kids were weighed after parturition (when
goats licked up newborns) with a spring balance (precision ± 0.05 kg). The winter season
refers to January and February of the chosen year and December of the previous year.
North-western Croatia belongs to the moderate climate zone. It is a moderate wet
region with mean annual precipitation of 870 mm per year and maximal insolation of
2000 hours per year (ZANINOVIC et al., 2008). All data were statistically analysed using
ANOVA and the Tukey test of pos-hoc analysis. Statistically significant results were at
P<0.05.
Results
Boer goats (n = 60) birthed 435 goat kids after 242 successful matings (only 17
matings were unsuccessful) in three consecutive years. The average birth weight (n =
435) was 3.48 ± 0.04 kg for all kids. Birth weight of goat kids in pluriparous Boer does
was significantly (P<0.05) higher in comparison to kids in primiparous with regard to
gender. The birth weight of Boer male goat kids was significantly (P<0.05) higher than
female Boer kids. Birth weight results are presented in the Table 1. Boer goat fertility in
north-western Croatia over the three-year period was 93.44%. Prolificacy in this herd was
180% or 1.80 kids per doe. Seasonal distribution of kiddings in this investigation was as
follows: 45% of Boer does delivered in winter, 31% in spring, 11% in summer and 13%
Vet. arhiv 82 (4), 351-358, 2012
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D. Đuričić et al.: Reproductive performance of boer goats in a moderate climate zone
in autumn. Does with singles accounted for 22.53% (n = 98), does with twins, 49.20% (n
= 107), does with triplets, 18.62% (n = 27), does with quadruplets 7.35% (n = 8) and does
with quintuplets 2.29% (n = 2).
Table 1. Average birth weights of the Boer kids according to parity and gender of newborn
Parity of doe
1.
2.
3.
4.
5.
Total
Gender of kid
male
female
male
female
male
female
male
female
male
female
n
68
54
64
54
38
33
59
28
14
23
435
M ± SEM
3.21 ± 0.08a
3.01 ± 0.10b
3.69 ± 0.10c
3.43 ± 0.09d
3.81 ± 0.08c
3.56 ± 0.12d
3.81 ± 0.09c
3.75 ± 0.10c
3.77 ± 0.22c
3.29 ± 0.11a
3.47 ± 0.04
Min
2.1
1.8
1.7
2.2
2.2
2.3
2.2
3.0
3.1
2.4
1.7
Max
4.4
5.1
5.0
4.8
5.1
4.9
5.4
5.0
5.3
4.3
5.4
SD
0.65
0.84
0.77
0.69
0.66
0.67
0.74
0.58
0.82
0.52
0.76
Values with different superscripts in the same column differ significantly (P<0.05)
Discussion
The improved Boer goat is thought of as highly fertile and well-known for its
fecundity (MALAN, 2000). In this research, the fecundity rate was very high at 241.66%
(2.42 kids/doe/year), in comparison with 209% (ERASMUS, 2000), 210% (MALAN, 2000),
and 212-215% (AUCAMP and VENTER, 1981). In Croatia, kiddings occurred mostly in
the winter and spring (about 76% of all kiddings). There was no equal distribution of
mating and kidding through the seasons. The average value of the interkidding period
of Boer goats in Croatia was 265.35 ± 4.42 days, or 1.38 kiddings/doe/year (ĐURIČIĆ
et al., 2009a). After Boer kids were weaned in early spring or midsummer (the anoestrus
period for European goat breeds begin in February and ends in May) (SHELTON, 1978;
CORTEEL, 1977; ĐURIČIĆ et al., 2009a), Boer does waited for the breeding season (August
to November) to mate. An average figure of 70 to 80% following natural mating (in
the autumn breeding) is considered normal to good for most European goat breeds
(SHELTON, 1978; CORTEEL, 1977), although the Boer goat had a better conception rate
(MALAN, 2000). The Boer goat conception rate in north-western Croatia over the threeyear period was very high at 93.44% (242 successful of 259 total matings in this study),
similar to MALAN (2000) who recorded a conception rate of about 90% in South Africa.
The average number of kids per doe depends on the goat breed (AMOAH et al., 1996).
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D. Đuričić et al.: Reproductive performance of boer goats in a moderate climate zone
In Nubian goats in Mexico, the average number of kids per doe was 1.77 (MELLADO
et al., 1991), as opposed to 2.3 to 2.9 kids in Egypt (MARAI et al., 2002), 1.94 ± 0.07 for
Spanish goat in the US, 1.89 ± 0.07 in Kiko (BROWNING et al., 2006), and 1.7 kids at
first to 2.4 kids at the sixth kidding in Creole goats of Guadeloupe (ALEXANDER et al.,
1999). In this herd, the prolificacy rate was 180%, lower than in Boer goats in Botswana at
193.42% (SEABO et al., 1994), and about 189% in South Africa (MALAN, 2000) and 185%
in the US (BROWNING et al., 2006). 435 newborn goat kids were born dead or alive in the
present three-year study period. Only 22.53% Boer does had singles (n = 98), similar to
the report by SEABO et al. (1994) of 27.7% singles of Boer goats in Botswana. AUCAMP
and VENTER (1981) recorded 65% twins in Boer goats, 54.57% (SEABO et al., 1994) in
Botswana and 50% (SKINNER, 1972). In this study, 49.20% (n = 107) of does had twins.
All authors concluded that more than half of Boer does had twins. This study recorded
18.62% triplets (n = 27). Similar results were obtained by SEABO et al. (1994) of 16.04%.
However, both these results are lower than the records of 33% triplets (ERASMUS, 2000)
or 27% triplets (AUCAMP and VENTER, 1981) and higher than 6.6% triplets (SKINNER,
1972). Litter size reduces the birth weight and survival rate of indigenous South African
goat kids (LEHLOENYA et al., 2005). The most important influences on birth weight in
small ruminants are the number of newborns, followed by number of parturitions, body
weight and condition of female around the time of parturition, nutrition and gender of
newborns (GARDNER et al., 2007). The average birth weight of Boer kids was 3.48 ± 0.04
kg (from 1.70 to 5.4 kg) in this study, similar to 3.21 ± 0.09 kg in the southeastern US
(BROWNING et al., 2004). However, LEHLOENYA et al. (2005) recorded a lower birth weight
by approximately 0.90 kg in South Africa. Due to improved management in this study, as
opposed to the semiarid and arid areas of South Africa, better results were obtained. The
performance of meat goats in intensive production in the European moderate climate zone
is not well known (DJURICIC et al., 2010; SAMARDŽIJA et al., 2011). Average birth weights
differ according to the gender of Boer kids and the number of newborn (BROWNING et
al., 2004; LEHLOENYA et al., 2005). It was also concluded that the average birth weight of
Boer male goat kids was higher than in female Boer kids (except in the fourth parturition).
The birth weight of goat kids in multiparous Boer does was higher than for goat kids in
primiparous does within the same gender. There was no equal seasonal distribution of
parturitions through the year. It is supposed that after transferring from the southern to
northern hemisphere, Boer goats gradually acclimated to a new seasonality. A higher
percentage of multiple births were expected during the optimal breeding season and more
goat kids during kidding season, as in most European goat breeds.
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Received: 4 July 2011
Accepted: 24 January 2012
________________________________________________________________________________________
ĐURIČIĆ, D., J. GRIZELJ, T. DOBRANIĆ, I. HARAPIN, S. VINCE, P. KOČILA,
I. FOLNOŽIĆ, M. LIPAR, G. GREGURIĆ GRAČNER, M. SAMARDŽIJA:
Rasplodni pokazatelji burskih koza u umjerenoj klimatskoj zoni. Vet. arhiv 82, 351358, 2012.
SAŽETAK
Cilj je istraživanja bio utvrditi rasplodne pokazatelje burskih koza u sjeverozapadnoj Hrvatskoj u
poluintenzivnom uzgoju kroz tri uzastopne godine. Šezdeset burskih koza u dobi od dvije do šest godina,
podijeljenih u tri skupine upotrijebljeno je u ovom istraživanju. Dobilo se 1,80 jareta po jarenju, to jest 2,41 jare
po kozi godišnje (435 jaradi u 242 jarenja). Fertilitet u burske koze iznosio je 93,44%. Koza s jednim jaretom
bilo je 22,53% (n = 98), s dvojkima 49,20% (n = 107), trojkima 18,62% (n = 27), četvorkima 7,35% (n = 8) i
2,29% s petorkima (n = 2). Prosječna porođajna masa jaradi iznosila je 3,48 ± 0,04 kg (od 1,70 kg do 5,4 kg).
Prosječna porođajna masa jaradi kod primiparnih koza (n = 68) iznosila je 3,21 ± 0,08 u muške i 3,01 ± 0,11 kg
u ženske jaradi (n = 54). Kod pluriparnih burskih koza porođajna masa jaradi bila je značajno veća (P<0,05) u
odnosu na jarad primiparnih koza neovisno o spolu. Porođajna masa muške jaradi burske rase bila je značajno
veća (P<0,05) u odnosu na žensku jarad. Nije postojala korelacija između starosti koze, rednog broja jarenja
i porođajne težine. Više od 76% burskih koza ojarilo se zimi (45%), a 31% u proljeće. Pretpostavlja se da se
burska koza nakon preseljenja iz Južne u Sjevernu hemisferu postupno prilagodila na novu sezonost. Burska
koza sa svojim genetskim potencijalom može poslužiti za križanje s domaćim kozama europskog podrijetla u
cilju poboljšavanja njihove reprodukcijske sposobnosti.
Ključne riječi: burska koza, spol jaradi, porođajna masa, reprodukcijski pokazatelji
________________________________________________________________________________________
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Vet. arhiv 82 (4), 351-358, 2012
Silvijo Vince