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Journal ArticleDOI

Rabbit production in bulgaria

01 Jan 2008-Biotechnology in Animal Husbandry (National Library of Serbia)-Vol. 24, pp 149-154
TL;DR: To change the rabbit production in Bulgaria as intensive or semi intensive it need to improve selection and feeding systems, to concentrate the farm, and to build new more modern farms with control systems of microclimatic parameters and which covered veterinarian requirements.
Abstract: The aim of the study was to present the situation of rabbit production in Bulgaria. As a whole the rabbit production in Bulgaria is in extensive stage. To change it as intensive or semi intensive it need to improve selection and feeding systems, to concentrate the farm, and to build new more modern farms with control systems of microclimatic parameters and which covered veterinarian requirements.

Summary (1 min read)

Introduction

  • Rabbit breeding is a small sector in Bulgarian animal production with big potential, because of: the good conditions for producing big quantity of rabbit meat in the country, absence of European limiting quotas and expanding of market needs of rabbit meat.
  • The bigger farms are located in Central North and Central South regions of Bulgaria, in which part are situated slaughterhouses.
  • The rabbits are 99.4% in the private sector and only 0.6 in government structure.

Farms with/ Farme sa:

  • Country consumption needs of meat in one side, but in the other, there are very good precondition for expanding this sector to be able to produce enough quantity rabbit meat for export to other countries.
  • The basic problem there is uncontrolled microclimatic parameters.
  • The does which are fed with low energy ration with high fiber level have better body composition which decreased their energy deficit in first lactation (Xiccato, et al.,1999).
  • There are not the strict prophylactic systems, but more of the farms apply vaccination against hemorrhagic diseases one or two time of the year, coccidiostatics in forage or in water, desinsection and disinfection every month.

Conclusions

  • As a whole it can say that the Bulgarian rabbit production is in extensive stage, but the legislation base is fully synchronized with requirement of European Union.
  • To change it as intensive or semi intensive it need to improve selection and feeding systems, to concentrate the farm, and to build new more modern farms with control systems of microclimatic parameters and which covered veterinarian requirements.

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Biotechnology in Animal Husbandry 24 (1-2), p 149-154, 2008 ISSN 1450-9156
Publisher: Institute for Animal Husbandry, Belgrade-Zemun UDC 639.112
RABBIT PRODUCTION IN BULGARIA**
I. Dimitrova
1*
, Tz. Dimitrov
2
, A. Teneva, H. Tzvetkova
3
1
Forestry University – Sofia, Bulgaria,
2
Ministry of Agriculture, Bulgaria,
3
Bulgarian board of bird and rabbit meat processing
** Original scientific paper
Corresponding author: *Ivona Dimitrova, E mail:ivonna_dimitrova@yahoo.co.uk
Abstract: The aim of the study was to present the situation of rabbit
production in Bulgaria. As a whole the rabbit production in Bulgaria is in
extensive stage. To change it as intensive or semi intensive it need to improve
selection and feeding systems, to concentrate the farm, and to build new more
modern farms with control systems of microclimatic parameters and which
covered veterinarian requirements.
Key words: rabbit production, breeding, reproductive system
Introduction
Rabbit breeding is a small sector in Bulgarian animal production with
big potential, because of: the good conditions for producing big quantity of
rabbit meat in the country, absence of European limiting quotas and expanding
of market needs of rabbit meat.
Rabbit numbers in Bulgaria, at the beginning of the transmission (1989
- 2000), were between 335 304 (for 1991) to 667 078 (for 1996). In 2001 it was
obtained the biggest reduction of raced rabbit number (233 480), because of
next reason: high level of forage price increasing, low augmentation tendency of
rabbit meat price and absence of export possibilities of rabbits or rabbit meat.
Since 2002 the rabbit number fluctuated, but the quantity of obtained rabbit
meat in meat processing enterprises at 2003 was lower (47.4 t) with 25.6% than
at 2002. In 2005 the number of farm raised rabbits had diminished with
46.22%, in the same time the rabbit does number had decreased with 19, 29%.
The bigger farms are located in Central North and Central South regions of
Bulgaria, in which part are situated slaughterhouses. The rabbits are 99.4% in
the private sector and only 0.6 in government structure.

I. Dimitrova, Tz. Dimitrov, A. Teneva, H. Tzvetkova
150
Table 1. Farm number and does concentration in 2003 and 2005 years
Tabela 1. Broj farmi i koncentracija zečica u 2003 i 2005 godini
Class/
Klasa
2003
Farm
number/
Broj farmi
2003
Rabbit
number/
Broj zečeva
2005
Farm
number/
Broj farmi
2005
Rabbit
number/
Broj zečeva
2005/2003
Farm
number/
Farme
%
2005/2003
Rabbit
number/
Zečevi
%
Total
rabbits/
Ukupno
zečeva
69457
651175
37354
525563
53.8
80.7
Does
Total/
Ukupno
zečica
62866
220248
33810
177771
53.8
80.7
Farms
with/
Farme sa:
1-10 does/
zečica
60538
171210
30907
115118
51.0
67.2
11-50
does/zečica
2261
42028 2783 53068 123.0 126.0
51-100
does/zečica
53
4076 116 8166 218.8 200.3
101-150
does/zečica
14
632 - - - -
Over 151
does/Više
od 151
zečice
5
2934
4
1420
80.0
48.3
The amount of Bulgarian rabbit population can not cover the recent
country consumption needs of meat in one side, but in the other, there are very
good precondition for expanding this sector to be able to produce enough
quantity rabbit meat for export to other countries. Now rabbit meat production
decreases (tabl.2) because of the low price of live rabbits, small number of
slaughterhouses and more complicated veterinarian requirement.

Rabbit production in Bulgaria
151
Table 2. Meat production 2002-2005
Tabela 2. Proizvodnja mesa 2002-2005
Class/Klasa
2002 20003 2004 2005
Slaughtered
rabbits/
Zaklani zečevi
thousand
tones/hiljade
tona
15.5
8.3
38.4
19.8
Rab meat
meso –
live weight
/živa masa
Tones/tone
45.9
21.2
99.8
58.0
live weight per
rabbits/
Živa masa po
zečevima
kg
2.9
2.6
2.6
2.9
Total
meat/Ukupno
mesa
Tones/tone 28.4 13.3 63.6
37.1
Dressing/
Randman
% 62.0 67.0 64.0
64.0
Slaughtered
weight per
rabbit/Težina
zaklanog zeca
kg
1.8
1.6
1.7
1.9
Liver
production/Pr
oizvodnja jetre
tones 3.6
1.6
Slaughterhous
es/Klanice
n 5 5 5 4
Rabbit production in Bulgaria can be expanded and changed as semi
intensive or intensive if some activity will be improved - genetic and selection,
reproductive system, feeding system, housing condition, prophylactics and
technology as a whole.
Genetic and selection. At 2005 in Bulgaria was raced 177 771 rabbit
does in 60 538 farms (table. 1), but only 2 087 of them (in 18 farms) were
controlled. White New Zealand and Californian breed represent the most part of
rabbit population. In country also are raced White giant, Flemish giant,
Chinchilla, new Bulgarian breed group – Veselina and hybrid ZIKA.
With aim to improve the hereditary traits of Bulgarian rabbit
population, 1500 animals (White New Zealand and Californian breed) were
imported from Italy and other 200 parent forms ZIKA were imported from
Germany at 2002. Utilization of unestimeted does and bucks, uncontroled
inbreeding and sporadic crosses (often with negative heterosis effect (Prayaga,
Eady, 2002; Rommers et al, 2002; Reddy et al., 2003) cause low productive

I. Dimitrova, Tz. Dimitrov, A. Teneva, H. Tzvetkova
152
traits of the big part of raced population – late maturation, low fertility and
prolificacy, low live weight, bad conversion rate of the feed, unsatisfacted meat
traits. Several non-governmental organizations (Bulgarian Rabbit Breeding
Association, National Society of Rabbit Breeders, Bulgarian board of bird and
rabbit meat processing) were established for improvement of population gene
fund.
Reproductive system. Most farms used natural mating; only several
farms practice artificial insemination with fresh semen (Grigorov, Georgiev,
2002). The does were mated for the first time earliest at age 150-days, because
of the low feeding level of young animals. This is the reason some authors to
suggest to inseminate for the first time young does not at fix age, but at fix live
weight – 75-80% of the live weight of old does (Leas et al., 1986; Roomers et
al., 2002). In most of Bulgarian rabbit farm there are not suitable feeding
program for young does, they can not to realize their growth potential. In good
condition of feeding it can be between 100-120 days of age for White New
Zealand and Californian rabbits.
Housing systems. Different housing systems were used in Bulgaria –
indoor, outdoor, or mix. Most farms have different rooms for the different rabbit
categories. The basic problem there is uncontrolled microclimatic parameters.
Feeding system. The most of the Bulgarian rabbit farms use feeding
with all ration pellets, but because of the varying quality of this forage, some of
the farmers add Lucerne hay to the ration.
Prophylactic system. The basic health problems depend of stage of
rabbit development and growth. One of the problem periods for rabbits is during
the two-week period after weaning known as a period with high mortality rate
of young rabbits (Nicodemus et al., 2002). This depend also and of the diet type
– high energy diet with low fiber level augment the percentage of mortality and
high fiber ration with low energy level reduce mortality rate, but slow down
growing in this important age period.
Next problematic stage – this is the period of the first lactation, which
can influence very negatively reproductive traits. Young does are very sensitive
of body energy deficit and this resulted in high percentage of replacement. The
does which are fed with low energy ration with high fiber level have better body
composition which decreased their energy deficit in first lactation (Xiccato, et
al.,1999).
There are not the strict prophylactic systems, but more of the farms
apply vaccination against hemorrhagic diseases one or two time of the year,
coccidiostatics in forage or in water, desinsection and disinfection every month.
Legislation base. For each part of Bulgarian rabbit production there are
the suitable legislation base – for feed producing, for rabbit cares, for does and
bucks producing, for veterinarian manipulations, for transportation and meat
processing.

Rabbit production in Bulgaria
153
Conclusions
As a whole it can say that the Bulgarian rabbit production is in
extensive stage, but the legislation base is fully synchronized with requirement
of European Union. To change it as intensive or semi intensive it need to
improve selection and feeding systems, to concentrate the farm, and to build
new more modern farms with control systems of microclimatic parameters and
which covered veterinarian requirements.
Proizvodnja zečeva u Bugarskoj
I. Dimitrova, Tz. Dimitrov, A. Teneva, H. Tzvetkova
Rezime
Cilj ovog rada je da se predstavi stanje u proizvodnji zečeva u
Bugarskoj. Generalno, proizvodnja zečeva u Bugarskoj je na ekstenzivnom
nivou. Da bi se promenila u intenzivnu ili polu-intenzivnu proizvodnju
neophodno je poboljšanje u selekciji i sistemima ishrane, izgradnja farmi i
novih savremenih farmi sa sistemima za kontrolu mikroklimatskih parametara i
koji su u skladu sa veterinarskim odredbama.
Ključne reči: proizvodnja zečeva, odgoj, reproduktivni system
References
GRIGOROV, I., GEORGIEV, S. (2002) Rabbit breeding. TU – Stara Zagora,
119pp.
LEBAS, F., COUDERT, P., ROUVIER, R., DE ROCHAMBEAU, H. (1986) The rabbit:
husbandry, health and production. FAO Animal Production and Health Series, Rome.
NICODEMUS, N., GURIERRES, I., GARCIA, J., CARABANO, R., DE
BLAS, C. (2002) The effect of remating interval and weaning age on the
reproductive performance of rabbit does. Anim. Res., 51, 517-523.
PRAYAGA, K., EADY, S. (2002) Performance of purebred and crossbred
rabbits in Australia: doe reproductive and preweaning litter traits. Austr J Agr
Res, 53 (9) 993-1001.

Citations
More filters
Journal Article
TL;DR: Statistical and multivariate analyses used to evaluate and compare the productive characteristics of local rabbit breed and F 1 crossbreds showed that the differences between two genotypes are significant only in improved rearing system.
Abstract: PaPa, L., K. Kume and a. LLambiri, 2013. Comprising study of productive characteristics of local rabbit breed and F 1 crossbreds (Californian Line (♂) x Albanian local rabbit breed (♀)) rearing in traditional and improved system. Bulg. J. Agric. Sci., 19: 806-809 a total of 267 male and female rabbits coming from local rabbit breed and F 1 crossbreds (Californian Line crosses (♂) x Albanian local rabbit breed(♀)) rearing in traditional and improved system were used for this study. The evaluation and comparison of productive performances live weight at weaning (WLW), live weight at slaughter age (SLW), and average of weight gain (AWG) of these two genotypes reared in two different systems was the aim of this study. Statistical and multivariate analyses used to evaluate and compare the productive characteristics of local rabbit breed and F 1 crossbreds showed that the differences between two genotypes are significant only in improved rearing system(SLW 2822.1 g vc 2338.5 g, P<0.01), AWG 26.24 g vc 35.51 g, P<0.05. The differences between sexes and the effect of rearing season are statistically significant in both rearing systems, (P<0.05). The Gompertz curves have significant differences affected by the genotype (P<0.01) only in rabbits reared in improved system. The rabbits of local breed reared in improved system produce more meat than in traditional system. (SLW 2338 g vc, 2042.4 g P<0.05 AWG 35.51 g, vc 26.24 g P<0.05). The (F 1 ) crosses could improve meat production from rabbits only if they are kept in improved system.

1 citations

Journal ArticleDOI
TL;DR: A significant degree of genetic variability is indicated of the studied polymorphic GH locus in the SPF2 rabbit group, compared to the both homozygous genotypes.
Abstract: Five rabbit populations of New Zealand White (NZW), Californian (CAL), crossbred NZW×GW and two generations of the synthetic population – SPF1 and SPF2 reared in Bulgaria were included in the present study with the aim of detecting the genetic variability of the growth hormone encoding gene (GH) via polymerase chain reaction with the restriction fragment length polymorphism analysis and direct sequencing. The targeted region of the rabbit GH gene was amplified and a fragment of a total of 231 bp was obtained in all studied populations. Allele identification was determined after enzymatic digestion, where two fragments of 62 and 169 bp correspond to allele C and an undigested fragment of 231 bp corresponds to allele T. Two additional bands of 107 and 124 bp evidenced A/G genetic polymorphism in the rabbit GH gene. Thirtyeight percent of the studied rabbits were carriers of the double mutation (C/T+A/G) in the same locus as the studied GH gene. The sequence analysis revealed two nucleotide substitutions – g.111C>T and g.156A>G in the non-coding region between the regulatory TATA box and 5’ UTR region, and a novel g.255G>A genetic variant in intron 1 of GH gene. The A>G transition was most frequent (40.57%), compared to the other ones, G>A (28.57%) and C>T (10.80%), respectively. The most frequent genotype in the NZW population was homozygous TT (0.93), with a prevalence of the T allele (0.97) over allele C (0.03) for g.111C>T SNP site. The distribution of the allele and genotype frequencies at the sites g.156A>G and g.255G>A in this rabbit group was identical, with the highest value of 0.93 for alleles A and G, respectively. The rabbit populations CAL and NZW×GW showed equal frequencies of the prevalent T allele (0.83) and for homozygous TT genotype (0.67) according to g.111C>T SNP. The highest values were obtained for the allele A (0.83) and for homozygous AA genotype (0.67) at c.33A>G SNP in these rabbit groups. The highest values (0.67, 0.60 and 0.80) for the heterozygous genotypes at g.111C>T, g.156A>G and g.255G>A SNPs, respectively, were detected among the SPF2 rabbit population, compared to the both homozygous genotypes. The results obtained in the present research indicates a significant degree of genetic variability of the studied polymorphic GH locus in the SPF2 rabbit group.

Cites background from "Rabbit production in bulgaria"

  • ...New Zealand White and Californian breed represent the majority of the rabbit population in the country (Dimitrova et al., 2008)....

    [...]

Journal Article
TL;DR: Californian rabbit does, fertilized until 48 th hour post litter weaning, show higher values of litter size on the 8 th and 16 th day post partum in comparison with control group with 19.5% and 18.7%, respectively.
Abstract: The aim of present research is the investigation on the fertilization until 48 th hour post litter weaning in Californian rabbit does over litter size, litter weight and average individual weight in young rabbit in birth, on the 8 th , 16 th , 21 st 35 th day post partum, as well as the absolute gain and the average daily gain from birth until 8 th day, from 8 th until 16 th day, from 16 th until 21 st day and from 21 st day until 35 th day. Californian rabbit does, fertilized until 48 th hour post weaning, show higher values of litter size on the 8 th and 16 th day post partum in comparison with control group with 19.5% and 18.7%, respectively. This method decreases average individual weight of young rabbit on the 16 th day with 18.6%. The absolute and average daily gain of a young rabbit in experimental group in the period from 8 th until 16 th day are 32.6% lower, and in the period from 16 th until 21 st day – 34% are higher than the control animals.

Cites background from "Rabbit production in bulgaria"

  • ...In Bulgaria, the majority of rabbits are bred in small rabbit farms (Dimitrova et al. 2008)....

    [...]

  • ...In Bulgaria, the majority of rabbits are bred in small rabbit farms (Dimitrova et al. 2008). Generally, the breeders use an extensive reproductive cycle and the does are mated few days post weaning of litter. The specialists, who work in professional rabbit farms, use a hormonal synchronization of estrus in order to realize on the market large batches of rabbits. The benefits and disadvantages of using are well – known. The hormonal treatments with Pregnant mare serum gonadotropin (PMSG) increase sexual receptivity, fertility, prolificacy (+5-10%), but PMSG treatment does not improve reproductive performance in non-lactating and receptive does and decrease fertility after several usage, because of antigenic properties and increase mortality rate of newborn rabbits (Maertens et al. 1995). According to Rommers et al. (2001), there also seems to be evidence that females born in smaller litters showed better reproductive performance than those from larger litters....

    [...]

References
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331 citations

Journal ArticleDOI
TL;DR: Feeding young does a high-fiber diet until their first kindling reduced the chemical and energy body deficit at the end of the first lactation.
Abstract: The feeding of a high-fiber and low-energy diet to young rabbit does from weaning to the first kindling was used to modify their body reserves, stimulate their energy intake, and reduce the energy deficit during the first lactation. Rabbits (53 per group) were given ad libitum access to either a control or high-fiber diet (CP, 17.6 vs 15.8% of DM; crude fiber, 15.5 vs 19.9% of DM; digestible energy, 2,565 vs 2,261 kcal/kg of DM, respectively) from weaning to their first kindling. During lactation, both groups received the same diet, which contained 19.3% CP, 16.5% crude fiber, and 2,634 kcal/kg digestible energy (dry matter basis). Four comparative slaughters were performed to estimate the chemical and energy balance of rabbit does at different physiological states: at the beginning of the trial (12 rabbits, 45 d of age), at mating (10 rabbits per group, 136 d), at kindling (10 rabbits per group, 167 d), and at the end of lactation (12 and 11 rabbits for the control and the high-fiber group, 197 d). Large changes in body weight and composition were observed between slaughters. From 45 d to mating, doe body fat and energy increased 7.93 and 4.64 times the initial content, respectively. During pregnancy, body protein concentration decreased from 203 to 186 g/kg. At the end of lactation, body fat and energy concentration were reduced to values close to those measured at 45 d of age. Dietary treatment affected body chemical and energy balance during pregnancy and lactation but not reproductive and lactational performance. The high-fiber diet stimulated feed intake from weaning to the first kindling but not dietary energy intake. During lactation, the rabbits fed the high-fiber diet ate 10 kcal.d -1 .kg live weight -.75 more and lost less body fat (-405 vs -504 g) and body energy (-3,628 vs -4,294 kcal) than the does fed the control diet (P < .001). In the same period, all does showed water and protein retention (185 and 45 g, on average) regardless of dietary treatment. In conclusion, feeding young does a high-fiber diet until their first kindling reduced the chemical and energy body deficit at the end of the first lactation.

62 citations

Journal ArticleDOI
TL;DR: Heavy does at first insemination might be able to benefit from the extra amount of BW to cope with the energy deficit during first lactation, and extra BW at start of reproduction improves litter size in the first parity but does not contribute to an improved feed intake or increased BW development during reproduction.
Abstract: A retrospective study was performed to evaluate the relationships between BW at first insemination and subsequent body development, feed intake, reproductive performance, and culling rate of rabbit does. Young rabbit does are vulnerable to body energy deficit in first lactation, resulting in decreased reproductive performance and high replacement rate. Heavy does at first insemination might be able to benefit from the extra amount of BW to cope with the energy deficit during first lactation. Data of three experiments were used in which does were given ad libitum access to feed during rearing and inseminated at 14.5 wk of age. The first two parities of each doe were recorded. Does were categorized in three groups based on their BW at 14.5 wk of age (first insemination): heavy (BW ≥ 4000 g), medium (BW 3500 to 4000 g), and small (BW < 3500 g). Among does that kindled, differences in BW at first insemination were related to differences in voluntary feed intake and body growth rate during rearing. Heavy does consumed more feed per day (+ 45 g/d, P < 0.001) and had a higher BW gain (+ 12 g/d, P < 0.001) than small does from weaning (4.5 wk) to 14.5 wk of age. Body weight at first insemination did not affect BW, feed intake, and culling rate during the first two parities. Heavy does were heavier at first insemination and remained so throughout the reproductive period, but they followed a similar BW curve as medium and small does. A higher BW at first insemination (14.5 wk of age) improved litter size in the first parity (8.9, 7.7, and 6.4 for heavy, medium, and small does, respectively, P < 0.05). Extra BW at start of reproduction improves litter size in the first parity but does not contribute to an improved feed intake or increased BW development during reproduction.

31 citations


"Rabbit production in bulgaria" refers background in this paper

  • ...Utilization of unestimeted does and bucks, uncontroled inbreeding and sporadic crosses (often with negative heterosis effect (Prayaga, Eady, 2002; Rommers et al, 2002; Reddy et al., 2003) cause low productive traits of the big part of raced population – late maturation, low fertility and…...

    [...]

Journal ArticleDOI
TL;DR: It is indicated that, in the conditions of reproductive management used, the numerical productivity can be increased through earlier mating and weaning, and about the possibility of increasing the receptivity of rabbit does at 4 d by using bio-stimulation methods.
Abstract: In this study we investigated the influence of the reproductive system on doe reproduc- tive performance. Two experimental treatments were compared using 36 cages per treatment over an 8-month production period. In the intensive system (IS) rabbit does were mate d4da fter parturition and the litters were weaned at 25 d of age, whereas in the control system (CS) the rabbit does were mated 11 d after parturition and the litters were weaned at 35 d of age. In both systems, the does that failed to mate, conceive or lost their pups were immediately given the opportunity to remate. Initially seventy-two New Zealand × Californian does were assigned to the treatments and used to determine the reproductive traits. Early mating of rabbit does associated with 25-d litter weaning (IS) allowed a shorter parturition interval (39.9 vs. 44.4 d, P = 0.0001) and a higher prolificacy (9.07 vs. 8.11 young rabbits born alive per litter, P = 0.06), litter size at 21 d (8.24 vs. 7.51, P = 0.06) and at weaning (8.21 vs. 7.42, P = 0.05) and tended to reduce the number of young rabbits born dead (0.52 vs. 0.94, P = 0.10) as compared to the animals in the CS treatment. Consequently, numerical productivity in- creased from 61.6 to 73.4 young rabbits per cage and year (P = 0.003). The intensively bred does had a lower receptivity to the male at the first mating (54 vs. 86.9%, respectively), but 88% of these does ac- cepted mating within 7da fter parturition. Fertility was high, above 80%, in all the matings. The treat- ments did not affect either the body weight (4301 g as average) or the mortality of the rabbit does (14.6%) and the mortality of the young rabbits during lactation (11.8%). Feed efficiency increased from 0.241 to 0.309 g of young rabbits weaned per g of feed when the remating interval was longer but these results cannot be compared because of the parallel increase in the age and weight of the young rabbits at weaning. This study indicates that, in the conditions of reproductive management used, the numerical productivity can be increased through earlier mating and weaning. However, more infor- mation is needed about the effect of this system on young rabbit performance after weaning, and about the possibility of increasing the receptivity of rabbit does at 4 d by using bio-stimulation methods.

22 citations


"Rabbit production in bulgaria" refers background in this paper

  • ...One of the problem periods for rabbits is during the two-week period after weaning known as a period with high mortality rate of young rabbits (Nicodemus et al., 2002)....

    [...]

Journal ArticleDOI
TL;DR: High phenotypic variances and coefficients of variation observed for traits NW and LWW indicate that good response could be realised through selection and selection methods, and Buck breed did not have any significant effect on any of the pre-weaning litter traits under study.
Abstract: Data from a rabbit breeding experiment were analysed to compare the doe reproductive and pre-weaning litter performance of 3 breeds of rabbits, namely New Zealand White (N), Californian (C), and Flemish Giant (F), and their crosses CN (C × N) and FN (F × N). The foundation stock of 152 rabbits was collected from 26 different sources in New South Wales, Australia. Data on reproductive traits, doe age at first successful mating (DA), doe weight at first successful mating (DW) arising from 104 does, conception rate (CR) from 808 matings, and kindling interval (KI) from 325 records of 119 does were analysed. Overall means for reproductive traits DA, DW, CR, and KI were 21 weeks, 3.6 kg, 0.75, and 7.4 weeks, respectively. DA, CR, and KI did not differ significantly among different breeds and their crosses. DW of C does was found to be significantly lighter than all other breed crosses in the study. Month-year of mating significantly affected DA, DW, and CR (P < 0.01), and as the parity number increased, there was a significant (P < 0.01) decrease in KI. As age of the doe at mating increased there was a significant increase in DW (P < 0.01), CR (P < 0.05), and KI (P < 0.01). Data from 436 litters of 157 does were included in the analysis of pre-weaning litter traits. The overall means for the pre-weaning litter traits were: number born per litter (NB, 8.1), number born alive per litter (NBA, 6.9), number weaned per litter (NW, 3.3), total litter birth weight (TLBW, 453.7 g), live litter birth weight (LLBW, 397.1 g), litter weaning weight (LWW, 2.8 kg), and average birth weight of kits per litter (ABW, 58.1 g). Doe breed significantly affected NW (P < 0.05), TLBW (P < 0.01), LLBW (P < 0.05), LWW, and ABW (P < 0.01). N does and crossbred does (CN and FN) performed better than purebred F and C does for NW and LWW. A significant heterosis of 41.9% and 40.8% was observed in CN does for traits NW and LWW, respectively. ABW of F does was significantly higher than that of all other breed crosses in the study. Buck breed did not have any significant effect on any of the pre-weaning litter traits under study. Parity significantly affected NW (P < 0.05), TLBW (P < 0.01), LLBW (P < 0.05), and ABW (P < 0.01). First parity does produced litters with significantly lighter birth weights. The month-year of birth effect was significant for NW, LWW (P < 0.01), and ABW (P < 0.05). The coefficients of variation for the doe reproductive traits and pre-weaning litter traits ranged between 12.1 and 59.5% and 16.1 and 93.3%, respectively. High phenotypic variances and coefficients of variation observed for traits NW and LWW indicate that good response could be realised through selection. Repeatability estimates for reproductive traits CR and KI were very low. Low to moderate repeatability estimates in the range 0.17-0.25 were observed for pre-weaning litter traits. Significant positive phenotypic correlations were observed between litter size and litter weight traits (0.30-0.97). A significant negative correlation was observed between ABW and NB (-0.56) and NBA (-0.36). Additional keywords: selection, repeatability, phenotypic variance, phenotypic correlation. Ae oAu K.a aa

17 citations

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Q1. What are the contributions in "Rabbit production in bulgaria**" ?

The aim of the study was to present the situation of rabbit production in Bulgaria.