Rabbit Breeding Research Articles

Bacillus coagulans alleviates hepatic injury caused by Klebsiella pneumoniae in rabbits.

As an opportunistic bacterial pathogen, Klebsiella pneumoniae (KP) is prone to causing a spectrum of diseases in rabbits when their immune system is compromised, which poses a threat to rabbit breeding industry. Bacillus coagulans (BC), recognized as an effective probiotic, confers a variety of benefits including anti-inflammatory and antioxidant properties. The purpose of this study was to investigate whether dietary BC can effectively alleviate hepatic injury caused by KP. In this study, the rabbits were initially pretreated with varying doses of BC (1×106, 5×106, and 1×107 CFU/g), followed by a challenge with KP at a concentration of 1011 CFU/mL. Liver tissues were harvested and processed for histological assessment using H&E and VG stains to assess structural alterations. Biochemical assays were employed to quantify the enzymatic activities of T-SOD and GSH-Px, as well as the MDA content. Furthermore, ELISA was utilized to detect the levels of inflammatory cytokine (IL-10, IL-6, IL-1β and TNF-α) and apoptotic-related gene (Bcl-2, Bax). Morphological observation indicated that BC can effectively mitigate KP-induced hepatic sinusoidal dilatation and congestion, as well as ameliorate the degree of hepatic fibrosis. Further analysis showed that BC significantly lowered MDA level in KP-treated rabbits, while enhanced the activities of T-SOD and GSH-Px. Additionally, ELISA result showed that BC pretreatment significantly reduced the levels of pro-inflammatory cytokines TNF-a, IL-6, IL-1β and pro-apoptotic gene Bax, while increasing the levels of anti-inflammatory cytokine IL-10 and anti-apoptotic gene Bcl-2 in KP-treated rabbits. Above data indicate that BC supplementation effectively attenuated oxidative stress and inflammatory response induced by KP through augmenting the activities of antioxidant enzymes and diminishing the levels of pro-inflammatory factors. Furthermore, it reduced the Bax/Bcl-2 ratio in the liver, thereby inhibiting KP-induced apoptosis. The treatment group receiving 5x106 CFU/g BC benefitted most from the protective effect.

Histological investigation for the effect of non-steroidal anti-inflammatory drug [diclofenac] on myocardium and lung of local breed Rabbit

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used as analgesics, anti-inflammatory agents, and antipyretics. The goal of this study was to perform a histological assessment of therapeutic and overdose dosages of diclofenac on the heart and lung tissues and serum Troponin I, Lactate Dehydrogenase, and Creatine Kinase. Thirty local breed rabbits weighing 1000 and 1400 grams were used, divided into four groups: therapeutic group I, overdose group II, overdose group III, and control group. Each group was injected intraperitoneum with different doses of diclofenac (2, 20, 50 mg/kg) once daily for 20 days, while the control group was injected with normal saline. The results of heart sections in the experimental groups showed numerous histological alterations. In group I, muscle fibers were degenerated, lipid droplets within hemolyzed, and fibrinoid deposition in congested blood vessels. Group II showed a woven appearance of muscle fibers, atrophied muscle fibers, and an increased presence of fibroblasts between blood vessels and adjacent muscle fibers. In group III, colloid appearances, pavement of inflammatory cells on the tunica intima of a congested blood vessel, muscle fiber necrosis, and hemosiderin deposits were observed between muscle fibers. The lung results referred to that group I had thickened the interstitial connective tissue, hyperplasia in connective cells, and cytoplasmic vacuolation of type I alveolus cells. In group II, the results revealed folded alveolar walls, droplets in hemolyzed congested blood vessel, and aggregation of desquamated cells within the lumen of alveoli. Group III showed engorged pulmonary vessel, folded alveolar walls surrounded with inflammatory cells infiltration. The results of serum Troponin I, creatine kinase and Lactate dehydrogenase showed a significant increase in between the experimental group when compared with control group, otherwise, the results of Troponin I in group III showed a significant decrease when compared with the control group on level 0.05%. Finally, the results of serum cholesterol a significant increase in between experimental when compared with control group on level 0.05%.

Rational use of the genetic potential of the domestic selection <i>белый великан</i> breed

The article presents the first rank-based, complex scientific development in Russian rabbit breeding. The results of the new rabbit breed creation are given on the basis of rational use of the genetic potential of White Giant rabbits and its improvement. New ways of estimating bucks and does based on a complex of features and modern molecular-genetic methods were developed for the accelerated creation of a new rabbit population. The first of its kind were rank-based evaluation according to rabbits’ maternal instinct, rank-based evaluation according to the rabbits’ complex of maternal traits (maternal instinct, fertility, the number of raised rabbits to weaning, the number of teats, lactation, and the live weight of the litter at birth and weaning), and rank-based evaluation according to the bucks traits complex, which included the reproductive qualities assessment, reproductive ability of mated does, and the micronucleus test’s assessment of the bucks genome stability. The multi-year selection results led to the creation of the new Russian rabbit breed, Velikorodskaya White, which can replace imports. The economic reason for the creation of the highly productive Russian rabbit breed is to ensure the independence of Russian farmers from the supply of imported breeding material.

Integration Analysis of Transcriptome Sequencing and Whole-Genome Resequencing Reveal Wool Quality-Associated Key Genes in Zhexi Angora Rabbits.

Wool quality is a crucial economic trait in Angora rabbits, closely linked to hair follicle (HF) growth and development. Therefore, understanding the molecular mechanisms of key genes regulating HF growth and wool fiber formation is essential. In the study, fine- and coarse-wool groups were identified based on HF morphological characteristics of Zhexi Angora rabbits. According to the results, the diameters of fine and coarse fibers, and the percentage of coarse fibers, were significantly lower in the fine-wool group than in the coarse-wool group. Additionally, the HF density was higher in the fine-wool group than in the coarse-wool group, and the diameters of both primary hair follicles and second hair follicles were finer in this fine-wool group. Moreover, RNA sequencing (RNA-seq) and whole-genome resequencing (WGRS) were performed to identify key candidate genes and potential genetic variations between fine- and coarse-wool groups. RNA-seq analysis revealed 182 differentially expressed genes (DEGs), with 138 upregulated and 44 downregulated genes in the fine-wool group. The WGRS analysis identified numerous genetic variants including 15,705 InDels and 83,055 SNPs between the two groups. Additionally, the joint analysis of RNA-seq and WGRS showed enrichment of the Wnt, JAK-STAT, and TGF-β signaling pathways. The key overlapping candidate genes such as DKK4, FRZB, CSNK1A1, TLR2, STAT4, and BMP6 were identified as potential crucial regulators of wool growth. In summary, this study provides valuable theoretical insights into wool quality and offers the potential for improving the molecular breeding of Angora rabbits.

Histological examination of rabbit tissues and internal organs during experimental infection with Trichinella spiralis larvae

The purpose of the research is to conduct a histological examination of the tissues and organs of rabbits experimentally infected with Trichinella spiralis larvae.Materials and methods. Necropsy was performed and organ and tissue samples were taken for histological studies 45 days after the experimental infection of White Giant rabbits with T. spiralis. The samples were fixed in 10% buffered formalin. Histological preparations: paraffin sections 4 μm thick, stained with hematoxylin and eosin.Results and discussion. A complete histological examination of the dermis, muscles and internal organs in experimental trichinellosis was conducted. The effect of T. spiralis larvae on the body of rabbits and the pathological changes in organs and tissues were determined. Pathological changes of an inflammatory nature were established in the heart muscle, kidneys, lungs, small intestine, spleen and muscle tissue and the muscle layer of dermis with the presence of accumulation of lymphocytes and eosinophils. Colored illustrations of the obtained sections with a detailed description are provided.

In vivo reduction of biofilm seeded on orthopaedic implants.

Electromagnetic induction heating has demonstrated in vitro antibacterial efficacy over biofilms on metallic biomaterials, although no in vivo studies have been published. Assessment of side effects, including thermal necrosis of adjacent tissue, would determine transferability into clinical practice. Our goal was to assess bone necrosis and antibacterial efficacy of induction heating on biofilm-infected implants in an in vivo setting. Titanium-aluminium-vanadium (Ti6Al4V) screws were implanted in medial condyle of New Zealand giant rabbit knee. Study intervention consisted of induction heating of the screw head up to 70°C for 3.5 minutes after implantation using a portable device. Both knees were implanted, and induction heating was applied unilaterally keeping contralateral knee as paired control. Sterile screws were implanted in six rabbits, while the other six received screws coated with Staphylococcus aureus biofilm. Sacrifice and sample collection were performed 24, 48, or 96 hours postoperatively. Retrieved screws were sonicated, and adhered bacteria were estimated via drop-plate. Width of bone necrosis in retrieved femora was assessed through microscopic examination. Analysis was performed using non-parametric tests with significance fixed at p ≤ 0.05. The width of necrosis margin in induction heating-treated knees ranged from 0 to 650 μm in the sterile-screw group, and 0 to 517 μm in the biofilm-infected group. No significant differences were found between paired knees. In rabbits implanted with sterile screws, no bacteria were detected. In rabbits implanted with infected screws, a significant bacterial load reduction with median 0.75 Log10 colony-forming units/ml was observed (p = 0.016). Induction heating was not associated with any demonstrable thermal bone necrosis in our rabbit knee model, and might reduce bacterial load in S. aureus biofilms on Ti6Al4V implants.

A review of perioperative mortality in pet rabbits in Australia.

Domestic rabbits have higher perioperative mortality rates (1.39%-4.8%) compared with dogs and cats (0.1%-0.2%), with cardiovascular and respiratory complications reported most. Understanding anaesthetic risk factors is essential to minimise mortality risks. To determine the perioperative mortality risks and risk factors in rabbits undergoing general anaesthesia. This retrospective cohort study evaluated 1757 records of rabbits that underwent general anaesthesia with inhaled isoflurane, categorised by the American Society of Anesthesiologists (ASA) physical status classification system (January 2019-April 2023). Data were collected on physical characteristics, anaesthetic protocol, airway management and patient outcomes. Potential risk factors were analysed using multivariable logistic regression modelling guided by directed acyclic graphs. The perioperative mortality risk was 2.05% (95% CI: 1.39, 2.71). Increased mortality was most associated with poorer health status (ASA score) and non-routine procedures. Following induction of anaesthesia, rabbits with a body mass of less than 1 kg (RR: 7.57, 95% CI: 1.18, 61.2) and Netherland Dwarf rabbits (RR: 23.4, 95% CI: 2.75, 200) were at higher risk. The use of a supraglottic airway device was protective against mortality during anaesthesia compared with endotracheal tubes (RR: 0.27, 95% CI 0, 3.78) and anaesthetic masks (RR: 0.42, 95% CI: 0, 3.71). Increased mortality was observed with a fentanyl-based protocol compared with a medetomidine-based protocol (RR: 4.62, 95% CI: 0.477, 44.7). Perioperative mortality was multifactorial, with health status, surgical complexity and physical characteristics representing primary risk factors. Clinicians should choose a suitable anaesthetic protocol, implement effective airway control and follow precautions for brachycephalic rabbit breeds.

DETERMINATION OF POL LUTANT EMISSIONS FRO M RABBIT ROOMS INTO ATMOSPHER IC AIR DEPENDING ON THE ACTION OF SOME PARATYPICAL FACTORS

The relevance of the work is determined by the need to determine coefficients of daily emission of pollutants from the premises of small livestock facilities. The aim ofe work was to compare the coefficients of the daily emission of pollutants into the atmospheric air from the rabbit hutch by calculation and instrumental methods. The coefficients of daily emission of pollutants were determined depending on the frequency of ma nure removal and the period of the year. Bibliographic, instrumental, mathematical and analytical research methods were used to fulfill the tasks. The experimental work was carried out in a brick room, equipped with a supply exhaust ventilation system with a mechanical drive, on the farm of the Cherkasy experimental station of bioresources NAAS. The research was carried out using rabbits of the poltavske sriblobreed, which were kept in galvanized cage batteries on a continuous concrete floor with one and two removal of manure. The density of planting rabbits was 12.5-13.0 heads/m2. Analytical studies have shown that in Ukraine, currently, there are no approved indicators of daily emission coefficients from rabbit farms for carbon dioxide and methane. However, they are both greenhouse gases. According to the results of experimental studies, the preliminary coefficients of the daily emission of carbon dioxide and methane for small rabbit breeding facilities were determined. They were, respectively, 1250g x day-1for CO2and 40g x day-1for CH4per 100 kg of live weight of rabbits. In addition, it is shown that the coefficients of daily emission of ammonia into atmospheric air for the winter and spring and summer and autumn periods, determined by the instrumental method, were 1.5-3.2 and 6.3-9.9times higher than the calculated ones, respectively. This may be due to the year-round keeping of the animals in a closed rabbit house with a concrete floor in galvanized cage batteries. At the same time, the coefficients of daily emission of fine dust (PM1-10) for the winter and spring and summer and autumn periods, determined by the instrumental method, were lower by 66.9-188.5 and 55.8-89.4 times, respectively. A significant variability of the coefficients of daily emission of polluting substances from the premises was established, depending on the period of the year, in particular, for ammonia, methane and fine dust. Two time removal of manure from the premises of the rabbit hutch likely reduced the average annual emission coefficients of carbon dioxide, ammonia, and methane by 8.4%, 7.9%, and 17.8%, respectively, but increased the average annual emission coefficient of fine dust by 3.9%

The efficacy of crossbreeding on reproductive and productive performance in New Zealand White and Flemish Giant rabbits

Crossbreeding is a well-established practice in livestock production aimed at improving reproductive and productive traits. This study evaluated the effects of crossbreeding on rabbits, focusing on comparisons between purebred Flemish Giant (n = 10), New Zealand White (n = 23), and their crossbred offspring (n = 27). Various parameters, including litter size, body weight, growth rate, and mortality, were assessed. The results demonstrated that crossbred rabbits presented a 15% faster growth rate than purebred rabbits, along with the lowest mortality rate and highest total meat output. This phenomenon, attributed to hybrid vigour, effectively blends the large frame of the Flemish Giant with the good litter size of the New Zealand White. Furthermore, statistical analyses, including ANOVA and Tukey‒Kramer’s honestly significant test, confirmed the significant effects of breed class on productivity, body weight, and carcass yield. Growth curves estimated using the Gompertz model highlighted the superior performance of crossbred rabbits under semiarid conditions. Notably, crossbreeding resulted in offspring with the highest dressing percentage and overall improved performance, offering potential advantages for rabbit producers worldwide.

The influence of drugs containing gluconolactone on the morphological parameters of the blood of rabbits

The work is devoted to the issues of using polyhydroxy acids in rabbit breeding. Antioxidants are extremely important compounds for living organisms. The authors considered the effect of gluconolactone used in the animal diet on the metabolic processes and physiological indicators of life activity of rabbits. Based on the studies (using gluconolactone as an example), the advisability of including supplements containing polyhydroxy acids in the rabbit diet is shown. Polyhydroxy acids, which are antioxidants, when regularly introduced with feed, help to increase the overall resistance of the body, stimulate the growth and healthy development of animals, which in turn leads to obtaining high-quality agricultural products. Rabbits, like other animals, can obtain antioxidants from plant foods, but their concentration may be insufficient for full protection against oxidative stress. To stabilize feed rations, various biologically active additives are used, which make it possible to increase the efficiency of animal rearing and improve productivity indicators. Thus, polyhydroxy acids, in particular gluconolactone, are well suited for sensitive animals that require the utmost care and gentle rearing.

GROWTH PERFORMANCE AND SEMEN CHARACTERISTICS OF MONGREL RABBIT BUCKS FED DIETARY LEVELS OF GARLIC (ALLUM SATIVUM) MEAL

This study was designed to evaluate the effect of garlic meal supplementation on growth performance and semen characteristics in rabbit bucks. Twenty-four (24) mixed breed rabbit bucks were used for this study. The bucks were allowed to acclimatize for two weeks before the commencement of the study, during this period, they were fed formulated diet and Calopogonium ad-libitum. Feed and clean drinking water were offered ad libitum to the experimental animals. Four different experimental diets were formulated with varying levels of 0.00, 0.50, 1.00 and 1.50% garlic meal as supplement and were coded as T1, T2, T3 and T4 respectively, with as control. The 24 bucks were weighed and randomly allotted into the four experimental treatments and replicated thrice with two rabbit bucks per replicate in a complete randomized design (CRD) for a period of 8 weeks. At the end of the feeding period, semen collection was done using a specially designed artificial vagina for rabbits. The data obtained were subjected to one-way analysis of variance (ANOVA) procedure using IBM Statistical Package for Social Science (SPSS) version 21. The result showed that garlic meal had significant effect (P<0.05) on final weight, total and daily feed intake. Garlic significantly influenced (p<0.05) sperm volume, motility, concentration and total cells per ejaculate however, did not affect sperm morphology. In conclusion, garlic meal supplementation at 1.0% (10g/kg) can improve some growth and seminal parameters in male rabbits.

Comparative analysis of meat quality of Laiwu black, Minxinan black and Hyla rabbits

Abstract. The meat rabbit industry in China relies on foreign breeds and synthetic lines; the development of superior domestic breeds has not yet been fully realised. We compared the meat quality of two Chinese local breeds of black rabbits (Laiwu black and Minxinan black) and Hyla commercial rabbits, to provide a reference for the utilisation of meat rabbit breeds. In the present study, 35 d old Laiwu black rabbits, Minxinan black rabbits, and Hyla rabbits (20 rabbits each) were selected and reared under identical feeding and management conditions for 7 weeks, after which 10 randomly selected rabbits from each group were slaughtered for the analysis of meat quality. The a∗ (redness) value of the two local breeds was significantly higher than that of Hyla rabbits (p<0.01). The shearing force and drip loss of Laiwu black rabbits were significantly lower than those of the other groups (p<0.05). The two local breeds exhibited significantly higher myoglobin levels than Hyla rabbits (p<0.01), while melanin was highest in the meat of Minxinan black rabbits. The essential amino acids (valine, isoleucine, leucine and lysine) were significantly lower in Minxinan black rabbits than in the other groups (p<0.05). Aldehyde (heptanal, octanal) contents in Minxinan black meat were significantly higher than those of the other groups (p<0.01); however, nucleotide (guanine, adenine) contents were significantly lower (p<0.01). Unsaturated fatty acids (oleic, linoleic, α-linolenic) were significantly higher in the meat of Laiwu black rabbits than in those of the other groups (p<0.05). Both Laiwu black and Minxinan black rabbits have certain advantages in terms of nutritional indicators while also having good meat colour and flavour. The results of this study provide a theoretical reference for the research and development of meat rabbit breeds.

Meta-analysis of genetic parameters for economic traits in rabbit using a random-effects model

The genetic improvement of rabbits helps increase their productivity and, consequently, increase the supply of animal protein for human consumption. The aim of this study was to perform a meta-analysis of genetic parameters (heritability and genetic correlation) for litter size at birth, litter weight at birth, litter size at weaning, litter weight at weaning and slaughter weight in rabbits. The final dataset contained 147 estimates of heritability and 32 estimates of genetic correlation across 34 articles published between 1992 and 2022. A random-effects model was used and the heterogeneity of estimates was assessed using Q and I2 statistics. Heritability estimates were of low magnitude for all traits, ranging from 0.09 to 0.18. The lowest heritability estimate was observed for litter size at weaning and the highest for slaughter weight. Most genetic correlations between traits were positive and moderate, ranging from 0.44 to 0.60. Significant heterogeneity among studies justified the use of random-effects models. The meta-analysis study provided reliable genetic parameter estimates and these results can support the development of rabbit breeding programmes..

A Case of Amami Rabbit Breeding in School of Yamato Village, Amami Oshima

A Case of Amami Rabbit Breeding in School of Yamato Village, Amami Oshima

Pedigree-Based Description of Danubia Alba Rabbit Breed Lines.

The diversity of livestock animal breeds is an integral part of global biodiversity and requires careful management for sustainability and future availability. Avoiding inbreeding is a crucial aspect of mating of breeding animals. Our aims were to describe the quality of the pedigree, generation interval, gene origin, inbreeding, and effective population size of Danubia Alba rabbit lines. Line "D" is the maternal, whereas lines "C" and "X" are used as the paternal lines. The pedigree information was followed back from the actual breeding rabbits up to the founder animals. The rabbits having offspring in 2023 were chosen as reference populations for each line. The complete generation equivalent (GenCom) was 17.68 for line "C", 18.32 for line "D", and 17.49 for line "X", respectively. The maximum number of generations (GenMax) was above 30 for each line. The estimated bottleneck effect is mostly the result of selection and not a real genetic loss. The Wright inbreeding coefficient (F_Wright) was the highest for the "X" line rabbits, whereas it was the lowest for the line "D". Kalinowski's decomposition of inbreeding showed that it originated mostly from the past; the current fixation of alleles was quite similar for the line "C" and "D". Based on the predicted effective population sizes, it seems that there is no problem in maintaining of Danubia Alba lines.

IMPLEMENTASI PERANCANGAN INTEGRASI SWOT BALANCED SCORECARD DALAM PENILAIAN KINERJA BISNIS PAKAN KELINCI PADA RABBIT BROTHERS DI KABUPATEN BANDUNG

Rabbit Brothers is one of the rabbit breeders established in 2017 located in West Java, West Bandung Regency. Rabbit Brothers rabbit feed sales in 2023 fluctuated. The tighter the competition, the company needs to determine strategies in business management to determine the company's current performance. The purpose of this study is to describe the strategy based on SWOT analysis, design a Rabbit Brothers rabbit feed strategy map based on SWOT Balanced Scorecard integration, performance measurement and performance assessment of Rabbit Brothers rabbit feed based on SWOT Balanced Scorecard integration, and improve Rabbit Brothers rabbit feed business performance based on SWOT Balanced Scorecard integration. The methods in this research are SWOT Analysis, Balanced Scorecard, Analytical Hierarchy Process Software Expert Choice, and Key Performance Indicator Lead Indicator. Rabbit Brothers rabbit feed strategy and strategy map, one of which is increasing profits, Rabbit Brothers rabbit feed performance is 93.04%, meaning that the company's performance is in a very healthy condition with the category (AAA). The performance of the four performance perspectives that are not optimal is improved on strategic initiatives, one of which is the content creation program.

Biostimulation methods based on chemical communication improve semen quality in male breeder rabbits

Biostimulation aims to optimize reproductive parameters as part of animal management practices by modulating animal sensory systems. Chemical signals, mostly known as pheromones, have a great potential in this regard. This study was conducted to determine the influence of short-term male rabbit exposure to different biological secretions, potentially pheromone-mediated, on reproductive parameters of males. Four groups of 18 males each were exposed to A) doe urine, B) 2-phenoxyethanol, C) doe vaginal swab, and D) distilled water (control), three times over a 2.5h exposure window, just before semen collection. Semen volume, sperm concentration and motility, as well as subpopulation analysis of the spermatozoa were assessed for each condition. Additionally, testosterone levels in blood samples were monitored at five time points over the 2.5 h exposure window. We found a higher percentage of motile, progressive, fast progressive and mid-progressive spermatozoa in any of the three experimental groups compared to the control group. In contrast, the semen volume and the percentage of immotile and non-progressive spermatozoa was generally higher in the control group. We then identified a higher proportion of a subpopulation of fast and progressive spermatozoa in groups A, B, and C compared to group D. Our data indicates that sperm motility increases when animals are exposed to specific biological fluids potentially containing pheromones, and that an increase in sperm volume does not correlate with an increase in spermatozoa concentration, progressiveness, and speed. Finally, no differences in testosterone levels were found among comparisons, although males of groups A and C (exposed to natural female biological fluids) showed a tendency towards higher testosterone levels. In conclusion, our results indicate that rabbit sperm quality increases upon exposure to the biological secretions proposed, thereby supporting further investigation into their molecular identity. This exploration could eventually pave the way for implementing the use of pheromones in rabbit husbandry to enhance reproductive and productive parameters in farmed rabbits.

423 Comparative post-weaning performance characteristics of four breeds of rabbit in hot humid climate of Nigeria

Abstract Rabbits are one of the most popular livestock breeds raised for their meat, fur, and companionship. Rabbit meat is fast gaining prominence as a healthier meat compared with beef, mutton, pork and chevon, which are mostly consumed in Nigeria. This study investigated breed differences in mortality, survival rates and post-weaning growth rate of rabbits reared under inimical environmental conditions. The animals were fed commercially compounded feed with 18% crude protein and 2300Kcal metabolizable energy with intermittent feeding of Panicum sp and Tridax sp. The study area, located at latitude 6.5867° N and longitude 3.9700° E, had an average daily temperature of 35°C and relative humidity of 64%, which negatively impacted the adaptation, survival rates and growth performance of the rabbits. A total of 48 weaner rabbits 8 wk of age, comprising 12 each (9 does and 3 bucks) of Checkered, Chestnut, Dutch and Hyla breeds were reared for 10 wk post-weaning. Mortality was recorded across the breeds and the body weights (BW) of the rabbits were also recorded on a weekly basis for the entire 10-wk period. The study evaluated survival rates across breeds and sex and BW gain. Statistical analyses were conducted using the Minitab software for Chi Squared test of independence for counts and descriptive statistics and general linear model analysis of variance for bodyweight gain. The statistical model describing the analysis was Yijk = µ + αi + (α:β)ij + eijk where αi is the ith fixed effect of breed and βj is the jth fixed effect of sex. The model accounted for 67.03% variation in total weight gain. Further mean separation was done using the Tukey’s multiple comparison procedure. Mortality rates across breeds on the average was 56.25%, with Checkered, Chestnut, Dutch and Hyla respectively recording 66.67%, 41.67%, 50.00% and 66.67% mortality, respectively. Mortality rate across sexes was 63.89% for does and 33.33% for bucks; however, mortality rates were independent (P > 0.05) of both breed and sex with a Chi-Squared value of 2.285 and 3.41, respectively, despite the numerical differences in mortality rates across breeds and sexes. Average total BW gain during the study period across the breeds and within breeds is as presented in Table 1. The nesting of sex within breed revealed that the only significant (P > 0.05) difference was noticed between the Hyla buck and Chestnut doe, while other means were not statistically different (P > 0.05). The Chestnut breed with the least BW gain adapted well in the environment with greatest survival rate, while the Hyla breed had the greatest BW gain and least survival rate throughout the study. This study indicated a negative relationship between survival rates and BW gain, that lighter breeds of rabbit tend to have greater survival rates than the heavier breeds.

THE EFFECT OF PIPER GUINEENSE AND XYLOPIA AETHIOPICA SUPPLEMENTATION ON THERMOREGULATORY RESPONSES IN RABBITS

The study was aimed at investigating the effect of Piper guineense and Xylopia aethiopica supplementation on thermoregulatory responses in rabbits. Twenty-four 4 months old rabbits (12 Chinchilla and 12 New Zealand White; average weight 1250 g) were used in a 10-week trial. Supplements of Uziza and Uda seeds were added at 10 g/kg each and a control diet without treatment. Rabbits were housed individually and randomly assigned to 6 groups (n=4/group) including control diet (no Uda or Uziza seeds), diet 2 (Control + Uziza seeds), and diet 3 (Control + Uda seeds) for each of the two breeds. The thermoregulatory responses – ear and rectal temperatures, respiratory and pulse rates were monitored and recorded weekly. Data were subjected to two-way analysis of variance on a 2 x 3 factorial block design in IBM SPSS 20. The afternoon rectal temperature was significantly (p<0.05) higher in the control diet (39.270C) than in those supplemented with Uziza (38.260C) and Uda (38.150C) seeds. The morning rectal temperature were significantly (p<0.05) higher in the Uda (37.700C) seed-supplemented diet than in the Uziza (37.370C) seed-supplemented diet compared to the control (37.200C) diet. Afternoon rectal temperature was significantly affected (p<0.05) by rabbit breeds as afternoon rectal temperature was significantly (p<0.05) higher in New Zealand White (38.680C) breeds than in Chincilla (38.440C) breeds. There was an interaction (p<0.05) between supplemented diets and rabbit breeds as this showed that morning pulse rate reduced by supplemented diet in Chinchilla breed but not in New Zealand White breed. Dietary supplementation of Uda and Uziza seeds influenced the thermoregulatory responses of rabbits.

ADAPTIVE POTENTIALS OF RABBIT (ORYCTOLAGUS CUNICULUS) GENOTYPES TO HEAT STRESS IN SEMI-ARID, NIGERIA

Rabbit production under the tropical condition is afected by environmental stress mainly from the effect of high ambient temperatures and high humidity, low wind speed and solar radiation. This study was conducted to investigate the adaptive potentials of rabbit genotvpes in the semi-arid environment. A total number of forty-eight rabbits from two genetic groups were used. Rectal temperature, respiratory rate, pulse rate and heat stress index were measured in Chinchilla and Dutch rabbitgenotypes during late dry season (LDS) and early rainy season (ERS). GLM procedure in SAS was used to analyze data whereby age, breed, sex and season were factors and heat stress indices were the variables. The results showed that breed of rabbit had a significant effect (p<0.01) on respiratory and pulse rates with Chinchilla 97.78±1.05 breath/minute and 141.66±1.46 breathminute respectively while Dutch 92.41±1.08 breath/minute and 134.66±12.68 breath/minute respectively. Breed had noeffect (p>0.01) on rectal temperature and heat stress index. The respiratory rate was significantly higher among female rabbits compared to their male counterpart (96.59±1.65breath/minute vs 93.59±1.08 breath/minute). Age has also significant (p<0.01) effect on the rectal temperature, pulse rate and respiratory rate. Eight weeks old rabbits had higher means values. The heat stress index obtained during the early rainy season was higher (p<0.01) than that obtained during the late dry season (2.20=0.02 vs 1.99±0.01). At the end of the study, Chinchilla rabbits were found to be more prone to heat stress than Dutch rabbits.