Impact of bee venom supplement on productive performance, health status and economics of weaned male rabbits: Considering breed and dosage factors.

The objectives of the present study were to investigate the potential effects of purified bee venom (BV) on various aspects of growth, carcass, antioxidant, intestinal bacterial count and economic considerations in rabbits. A total of 240 male rabbits, comprising two distinct breeds (V-Line and New Zealand White [NZW]), 5 weeks old, with an average live body weight (BW) of 680 ± 20 g, were randomly divided into six groups, each containing 30 rabbits. Each group had five replicates, with six rabbits in each replicate. The allocation of animals to the groups followed a fully factorial design, incorporating two factors: breed (V-Line and NZW) and four levels of purified BV derived from Apis Mellifera. The control group (G1) received a basal diet without additives. The other three groups (G2, G3 and G4) received the basal diet with BV supplementation in their drinking water at 0.5, 1 and 2 mg/L respectively. The study results indicated that NZW rabbits significantly enhanced feed conversion ratio while maintaining consistent carcass attributes compared to the V-Line breed. Despite variations in growth parameters being less pronounced, the supplementation of BV at levels of 1-2 mg/L demonstrated significant improvements in various other parameters. Notably, the interaction between the BV supplement and the breed factor (p < 0.001) yielded notable distinctions in most production metrics, encompassing BW, weight gain, feed conversion, carcass attributes and blood parameters. Increasing levels of BV supplementation, particularly at 1 mg/L, led to substantial improvements in serum and tissue metabolites. Moreover, the levels of total bacterial count and Escherichia coli in the jejunum and colon were significantly diminished, while the population of Lactobacilli in the colon was augmented (p < 0.001) in rabbits from both breeds receiving BV supplementation (1-2 mg/L) compared to the control group. The results underscore the potential of the BV supplement to enhance final weights, bolster antioxidant status and mitigate the presence of pathogenic bacteria, thereby contributing to enhanced economic efficiency in rabbits. Further inquiries are warranted to comprehensively investigate BV supplementation's potential advantages and limitations across different breeds and dosage levels.

Assessment of thermal changes in water buffalo mobilized from the paddock and transported by short journeys.

Evaluating the welfare of buffaloes during transport is key to obtaining and commercializing high-quality meat products; however, effective assessments require recognizing several stressors that activate physiological mechanisms that can have repercussions on the health and productive performance of species. The aim of this study was to evaluate the surface temperatures of different body and head regions in this species during events prior, and posterior, to transport for short periods; that is, from paddock to loading. The second goal was to determine the level of correlation between thermal windows. This study used infrared thermography (IRT) to evaluate the surface temperature of 624 water buffaloes (Buffalypso breed) during 12 short trips (average duration = 2 h ± 20 min) by focusing on 11 regions of the body (Regio corporis), in the head regions (Regiones capitis) the face regions (Regiones faciei), Orbital region (Regio orbitalis) with special attention to structures such as the lacrimal caruncle, periocular area and lower eyelid (Regio palpebralis inferior); nasal region (Regio nasalis) with special attention to nostril thermal window; and regions of the skull (Regiones cranii) such as auricular region (Regio auricularis) with special attention to auditory canal and frontal-parietal region (Regio frontalis-parietalis) and trunk region (Truncus regionis) such as thoracic and abdominal regions, regions of the vertebral column (Columna vertebralis) with the thoracic vertebral region (Regio vertebralis thoracis) and lumbar region (Regio lumbalis); and regions of the pelvis limb (Regiones membri pelvini). Recordings were made during seven phases: paddock (P1), herding (P2), corral (P3), chute handling (P4), shipping (P5), pre- (P6), and post-transport (P7). A total of 48,048 readings were obtained from 11 thermal windows. The results showed that the surface temperatures of the windows increased by as much as 5°C during P2, P3, P5, P6, and P7 compared to P1 and P4 (p < 0.0001). Differences of at least 1°C were also observed between thermal windows in the craniofacial, lateral corporal, and peripheral zones (p < 0.0001). Finally, a strong positive correlation (r = 0.9, p < 0.0001) was found between the thermal windows. These findings lead to the conclusion that the surface temperature of the craniofacial and corporal regions of buffaloes transported for short periods varied in relation to the phase of mobilization (from paddock to post-transport), likely as a response to stressful factors, since herding and loading increased the thermal values in each window. The second conclusion is that there are strong positive correlations between central and peripheral thermal windows.

The growth curve determination and economic trait correlation for Qinchuan bull population.

Carcass weight, as a measure of meat yield, and body measurements are directly correlated traits in livestock. However, longitudinally collected phenotype records of local breeds are not comprehensive. The research was performed on Qinchuan bull population to understand their growth and development, and data from Qinchuan bull that was weighed and measured at birth, 6, 12, 18, and 24 months of age was analyzed. Furthermore, Logistic, Brody, Gompertz, and Bertallanffy were used to fit the growth curves for weight and body size traits. The results showed that the four curve models have good fitting degrees for the weight and body size (R2 > 0.99), and the Bertallanffy model exhibited a good fit to the measured data of body weight, and the model estimated the inflection point of body weight as (5.43 months of age, 122.01 kg). Particularly, the limited mature body weight can reach 557.8 kg by the Brody model. Body weight was significantly positively correlated with body height, hip height, body length, chest circumference, abdominal girth, and calf girth (p < 0.0001), and the correlation between body weight and body length was the highest (r = 0.975). The regression equation predicting body weight was Y = -275.691 + 3.28 X3 + 1.311 X4 - 0.397 X5.

Inhibition of microbial pathogens in farmed fish.

Aquaculture, also known as aqua farming, is defined as farming fish, crustaceans, mollusks, aquatic plants, algae, and other marine organisms. It includes cultivating fresh- and saltwater populations under controlled conditions compared to commercial fishing or wild fish harvesting. Worldwide, carp, salmon, tilapia, and catfish are the most common fish species used in fish farming in descending order. Disinfectants prevent and/or treat different infections in aquatic animals. The current review indicates the uses of different disinfectants against some important pathogens in aquaculture, with particular reference to tilapia (Oreochromis niloticus) farming. A single review cannot cover all aspects of disinfection throughout aquaculture, so the procedures and principles of disinfection in tilapia farming/aquaculture have been chosen for illustration purposes.

Prevalence and Molecular Characterization of Extended-Spectrum ß-Lactamases and AmpC ß-lactamase-Producing Enterobacteriaceae among Human, Cattle, and Poultry.

Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae are a universal public health alarm frequently identified among humans, animals, and poultry. Livestock and poultry production are a possible source of multidrug-resistant microorganisms, including ESBL-producing Enterobacteriaceae, which confer antimicrobial resistance to different ß-lactam antimicrobial agents. From January to May 2020, a cross-sectional study was carried out in three dairy cattle farms and four poultry farms in different districts of northern Egypt to assess the prevalence of ESBLs, AmpC beta-lactamase-producing E. coli and Klebsiella in livestock, poultry, and human contacts, and to investigate the genetic relatedness of the recovered isolates. In total, 140 samples were collected, including human fecal samples (n = 20) of workers with intimate livestock contact, cattle rectal swabs (n = 34), milk (n = 14), milking machine swabs (n = 8), rations (n = 2), and water (n = 2) from different cattle farms, as well as cloacal swabs (n = 45), rations (n = 5), water (n = 5) and litter (n = 5) from poultry farms. The specimens were investigated for ESBL-producing E. coli and Klebsiella using HiCrome ESBL media agar. The agar disk diffusion method characterized the isolated strains for their phenotypic antimicrobial susceptibility. The prevalence of ESBL-producing Enterobacteriaceae was 30.0%, 20.0%, and 25.0% in humans, cattle, and poultry, respectively. Further genotypic characterization was performed using conventional and multiplex PCR assays for the molecular identification of ESBL and AmpC genes. The majority of the ESBL-producing Enterobacteriaceae showed a multi-drug resistant phenotype. Additionally, blaSHV was the predominant ESBL genotype (n = 31; 93.94%), and was mainly identified in humans (n = 6), cattle (n = 11), and poultry (14); its existence in various reservoirs is a concern, and highlights the necessity of the development of definite control strategies to limit the abuse of antimicrobial agents.

Fructooligosaccharide Supplementation Boosts Growth Performance, Antioxidant Status, and Cecal Microbiota Differently in Two Rabbit Breeds.

The present study examined the effects of fructooligosaccharide (FOS) supplementation in drinking water on the growth performance, carcass characteristics, hematological and biochemical parameters, antioxidant status, and cecal microbiota of New Zealand White (NZW) and APRI rabbits. A total of 180 male NZW and APRI rabbits (aged five weeks; average live body weight 700 ± 39 g) were divided into six groups (30 rabbits/group; 5 replicates/group) in a two × three factorial arrangement. Rabbits of each breed were randomly assigned to one of three treatments of FOS (control; 0.00, FOS-0.5, and FOS-1.0). Results showed that rabbits' final body weight, FBWG, and carcass traits were considerably enhanced compared to those in the control group. The interaction effect of the supplement with the rabbit breed increased the growth, carcass traits, and hematobiochemical and antioxidant parameters with increasing FOS levels. In the cecum of both rabbit breeds, the total bacterial count and Escherichiacoli population were considerably low, with a substantial increase in the number of Lactobacilli supplemented by FOS. In conclusion, FOS supplementation enhanced growth and carcass traits by improving the hematobiochemical parameters and antioxidant status and reducing cecal pathogenic bacteria in both breeds.

Potentials, prospects and applications of genome editing technologies in livestock production.

In recent years, significant progress has been achieved in genome editing applications using new programmable DNA nucleases such as zinc finger nucleases (ZFNs), transcription activator-like endonucleases (TALENs) and the clustered regularly interspaced short palindromic repeats/Cas9 system (CRISPR/Cas9). These genome editing tools are capable of nicking DNA precisely by targeting specific sequences, and enable the addition, removal or substitution of nucleotides via double-stranded breakage at specific genomic loci. CRISPR/Cas system, one of the most recent genome editing tools, affords the ability to efficiently generate multiple genomic nicks in single experiment. Moreover, CRISPR/Cas systems are relatively easy and cost effective when compared to other genome editing technologies. This is in part because CRISPR/Cas systems rely on RNA-DNA binding, unlike other genome editing tools that rely on protein-DNA interactions, which affords CRISPR/Cas systems higher flexibility and more fidelity. Genome editing tools have significantly contributed to different aspects of livestock production such as disease resistance, improved performance, alterations of milk composition, animal welfare and biomedicine. However, despite these contributions and future potential, genome editing technologies also have inherent risks, and therefore, ethics and social acceptance are crucial factors associated with implementation of these technologies. This review emphasizes the impact of genome editing technologies in development of livestock breeding and production in numerous species such as cattle, pigs, sheep and goats. This review also discusses the mechanisms behind genome editing technologies, their potential applications, risks and associated ethics that should be considered in the context of livestock.

Growth, immunity, relative gene expression, carcass traits and economic efficiency of two rabbit breeds fed prebiotic supplemented diets.

The current study designed to evaluate the effect of oligosaccharide supplemented diets on growth performance, histomorphometric changes, economic efficiency and genetic expression of some growth and immunity-relative genes. One hundred and twenty weaned male rabbits, six weeks of age of two breeds (NZW and APPRI) were randomly allocated into six equal groups; the first supplemented with 0.3% Mannan-oligosaccharide (MOS), the second supplemented with 0.05% Isomalto-oligosaccharide (IMO) and the third considered a control group. Each group contained ten equal replicates. The highest Final body weight and feed consumption were recorded in MOS and IMO groups compared with control. Fortified feed diet with IMO significantly increased duodenal villi area and length than MOS and control groups. At the same time, Spleen white bulb area and length were significantly higher in MOS and IMO than control. Supplementation of MOS and IMO significantly improved carcass traits, economic efficiency and induced certain modifications in some major key genes involved in the regulation of nutrients metabolism, immunity and growth in different tissues. In conclusion, dietary supplementation of MOS and IMO had a desirable positive impact on productive and economic efficiency in the rabbit.

CEBPß binding directly to the promoter region drives CEBPɑ transcription and improves FABP4 transcriptional activity in adipose tissue of yak (Bos grunniens).

Fatty acid binding protein 4 (FABP4) was crucial to fatty acid uptake and intracellular transport. However, the mechanisms regulating yak (Bos grunniens) FABP4 transcription were not determined. In the current study, predominant expression levels of yak FABP4 were identified in subcutaneous fat and longissimus dorsi muscles by quantitative real-time polymerase chain reactions (qPCR). The CCAAT/enhancer binding protein alpha (CEBPα) and myocyte enhancer factor 2A (MEF2A), as transcriptional activator or repressor in the promoter region of FABP4, were confirmed by both site-directed mutagenesis experiment and chromatin immunoprecipitation assay. Additionally, molecular mechanisms of CEBPɑ regulation were analyzed to explore the transcriptional regulatory property of FABP4, which indicated that transcriptional activity of CEBPɑ depended on CCAAT/ enhancer binding protein beta (CEBPß) transcription factor. Our results demonstrated that CEBPß binding directly to the promoter region drove CEBPɑ transcription, improving yak FABP4 transcriptional activity in adipocytes. This mechanism expanded the information on the transcriptional regulatory network of adipogenesis.

The role of forskolin as a lipolytic stimulator during in vitro oocyte maturation and the in vitro embryo production of livestock.

Cryopreservation is a modern technique which assists in the preservation of genetic material from oocytes and embryos for a long time. However, elevated vulnerability to cryopreservation due to the large accumulation of intracellular lipids within oocytes or embryos avoids success of this method. These lipids remain the main crucial factor limiting survival rates of oocytes and embryos after thawing. Lipid ingathering in the oocyte cytoplasm augments lipid peroxidation (LPO) and oxidative stress increases the apoptosis process, declines the viability after thawing, declines cytoskeleton actin filament injuries, lowers the blastocyst rates and reduces cryotolerance in the early stages of embryo development. There have been several attempts to reduce the ingathering of intracellular lipids in oocytes or embryos during the cryopreservation process, in that way enhancing the competence of cryopreserved oocytes or embryos and increasing their viability. One of the most applied agents for chemical delipidation is forskolin. Forskolin exhibited a possible part in improving the oocytes cryopreservation through stimulating cyclic adenosine monophosphate (cAMP) production. The main purpose of cAMP modulation is to provide energy to sustain the mammalian oocytes´ meiotic arrest. The purpose of the existing article is to assess and offer more evidence concerning the forskolin utilization as a modulator of cAMP during the cryopreservation of oocytes and its influence on meiosis completion and the reorganization of cytoplasm, which are prerequisites for the development of oocytes in addition to the contribution to fertilization and subsequently, the development of embryos.

Variations in the insulin receptor substrate 1 (IRS1) and its association with growth traits in Chinese black Tibetan sheep (Ovis aries).

This paper presented the results on the study of insulin receptor substrate 1 (IRS1) polymorphisms in Chinese black Tibetan sheep. Via DNA direct sequencing, four variations within 3' untranslated region (UTR) of IRS1, including g.9382T > G, g.9569T > G, g.9572C > T and g.9695A > C were detected in the black Tibetan sheep population. Based on the χ2 test, those four loci deviated from Hardy-Weinberg equilibrium (p < 0.05). In g.9569T > G locus, genotype of GG possessed advantage on body weight (p < 0.05). In g.9572C > T locus, individuals with genotype of TT homozygous mutation decreased significantly on body weight, withers height, body length and chest circumference (p < 0.05 or p < 0.01). In g.9695A > C locus, the body weight and chest circumference were also higher in AA carriers than in CC carriers (p < 0.05). Our results provided evidence that polymorphisms in IRS1 were associated with growth efficiency traits by quantitative genetic analysis, and may be used for marker-assisted selection in Chinese indigenous sheep.

Role of multidrug resistance-associated proteins in cancer therapeutics: past, present, and future perspectives.

Cancer, a major public health problem, is one of the world's top leading causes of death. Common treatments for cancer include cytotoxic chemotherapy, surgery, targeted drugs, endocrine therapy, and immunotherapy. However, despite the outstanding achievements in cancer therapies during the last years, resistance to conventional chemotherapeutic agents and new targeted drugs is still the major challenge. In the present review, we explain the different mechanisms involved in cancer therapy and the detailed outlines of cancer drug resistance regarding multidrug resistance-associated proteins (MRPs) and their role in treatment failures by common chemotherapeutic agents. Further, different modulators of MRPs are presented. Finally, we outlined the models used to analyze MRP transporters and proposed a future impact that may set up a base or pave the way for many researchers to investigate the cancer MRP further.

Yeast as growth promoter in two breeds of growing rabbits with special reference to its economic implications.

The present study investigated the effects of dietary supplementation of Saccharomyces cerevisiae (SC) on growth performance, carcass traits, blood biochemical parameters, histological changes in intestinal wall and economic indices in two breeds of weanling rabbits (V-Line and Rex). One-hundred and twenty weaned male rabbits were allotted randomly into four groups in factorial arrangement. The results could be summarized as follows: dietary supplementation of SC significantly accelerated body weight gain (BWG), reduced feed conversion ratio (FCR) and increased profit. The highest BWG and the lowest FCR were noticed in each breed when interacted with SC. There were non-significant differences in carcass traits due to the studied factors, except in loin and dressing percentages. The highest percentages of loin and dressing were obtained from V-line when fed diet supplemented with SC. The treated rabbits with yeast were characterized by an increase in Brunner`s gland and villi. Dietary Supplementation of SC decreased blood total glycerides and cholesterol and increased blood total protein, albumin and A/G ratio. The treated group showed higher profitability than the control. Conclusively, dietary supplementation of SC provided beneficial effects in growth performance and profitability of rabbits. Finally, dietary supplementation of SC is highly recommended in growing rabbits.

Effect of adding different concentrations of L-arginine to Tris-yolk extender on the quality of sub-fertile ejaculates in buffalo.

To investigate the effect of supplementation of L-arginine (AR) on sub-fertile buffalo-bulls' ejaculates, 25 ejaculates of poor motility (40 to 55%) were collected by artificial vagina from 5 buffalo-bulls and extended with Tris-yolk extender (1:10) supplemented with different concentrations of AR (0, 3, 4, 5, and 6 mM). Semen was cooled gradually to 4 °C within 2 h and incubated at 4 °C for additional 2 h. Incubated semen samples were evaluated by computer-assisted semen analysis. Results showed that addition of 5 mM AR increased (P < 0.05) total sperm motility and rapid progressive motility percentages, while decreased (P < 0.05) non-motile sperm and static sperm percentages compared with AR-free (control) extender. Increasing the AR level to 6 mM increased (P < 0.05) the percentages of sperm progressive motility and rapid and slow progressive motilities, while decreased (P < 0.05) the non-progressive sperm motility percentages compared with AR-free extender. Supplementation of 5 mM AR improved (P < 0.05) sperm straight linear, curve linear, and average path velocities (36 ± 0.13, 20.6 ± 5.3, and 33.2 ± 8.5, respectively) in comparing with control and other AR treatments. Addition of AR (5 and 6 mM) improved (P < 0.05) the percentages of vitality (89.8 ± 1.9 and 80.0 ± 3.4, respectively), normality (44.3 ± 3.6 and 44.8 ± 1.5, respectively), and functional sperm (20.4 ± 8.6 and 21.0 ± 0.61, respectively), and decreased abnormal neck and tail percentages compared with AR-free extender. All AR levels decreased (P < 0.05) the abnormal neck and tail percentages. Addition of all AR levels had no significant (P > 0.05) effect on the activity of aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase in semen extender. Supplementation of Tris-yolk extender with L-arginine (5 or 6 mM) can improve sperm motility, velocity, vitality, and functional sperm and can decrease tail and neck abnormalities of sub-fertile buffalo ejaculate after 4 h incubation at cool temperature.

ß-glucan administration improves growth performance and gut health in New Zealand White and APRI rabbits with different breed responses.

This study investigated the effects of oral administration of ß-glucan 1,3 (pharmaceutical grade 10%) on growth performance and carcass traits in two breeds of weanling rabbits adapted to survive in Egypt, New Zealand White (NZW) and Animal Production Research Institute (APRI) rabbits, with special attention to relative mRNA expression of interleukins and antioxidant enzyme genes, biochemical, and histological alterations. Oral administration of ß-glucan with doses 0.25 and 0.5 ml per one-liter of drinking water significantly accelerated body weight gain (BWG) in both rabbits' breeds, reduced total feed consumption (FC), and reduced feed conversion ratio (FCR), especially the 0.5 ml per one-liter dose in both rabbit breeds. There are remarkable differences in all the growth performance traits due to breed effect. The interaction effect between ß-glucan and breed significantly improved BWG, FC, and FCR. There were non-significant differences in all carcass traits studied due to oral administration of ß-glucan with both doses, except in dressing percentages. The highest of the dressing percentages were observed at doses 0.25 ml per one-liter (51%) and 0.5 ml per one-liter (52%) compared with control (50%). Our findings show significant variations in the final BW, total daily gain, feed consumption, and total feed conversion ratio between NZW and APRI rabbits. Absence of significant differences in the hot carcass weight and dressing percentage between the genetic groups had been reported in this study. Supplementing NZW and APRI rabbits with ß-glucan increased blood total protein and globulin. The duodenal villi dimensions, splenic lymphoid diameter, muscular fiber diameter, and muscular glycogen areas were significantly increased by ß-glucan administration. Expression of intestinal interleukin-18 (IL-18) in NZW rabbits treated with 0.25 and 0.5 doses of ß-glucan was significantly upregulated and enhanced the immune response. ß-glucan upregulated the expression of intestinal occludin mRNA particularly at dose 0.5 ß-glucan as well as upregulated intestinal superoxide dismutase 1 (SOD1) and glutathione peroxidase 1 (GPx1), which modulates anti-inflammatory and antioxidant properties. In conclusion, oral administration of ß-glucan at a dose of 0.25 or 0.5 ml per one-liter drinking water provided beneficial effects in the growth performance and health status of rabbits.

Efficacy of Different Drenching Regimens of Gluconeogenic Precursors during Transition Period on Body Condition Score, Production, Reproductive Performance, Subclinical Ketosis and Economics of Dairy Cows.

A total of 108 Holstein cows were used to evaluate the effect of drenching propylene glycol (PG) either individually or in combination with glycerol (G) on body condition score (BCS), production, reproductive performance, protection against subclinical ketosis and economic benefit of dairy cows during the transition period. The six groups (n = 18/group) were; Control group, cows received no treatment; PG300, cows were drenched 300 mL PG for 7 days pre-expected day of calving and 21 days post-calving; PG400, cows were drenched 400 mL PG for 7 days pre-and 7 days post-calving; PG500, cows were drenched 500 mL PG for 10 days pre-and 10 days post-calving; GPG150, cows were drenched a mixture of 150 mL G and 150 mL PG for 21 days pre-and 21 days post-calving; GPG250, cows were drenched a mixture of 250 mL G and 250 mL PG for 21 days pre-and 21 days post-calving. BCS at 30 days in milk (DIM) was significantly higher in all treated groups in comparison to the control one and the best values were observed in GPG250, GPG150 and PG500 groups. Lactation length (LL) was significantly (p < 0.001) shorter in GPG250, GPG150 and PG500 groups than control group. There was a significant increment in 305 milk yield (p < 0.001) and average daily milk yield (p < 0.001) in GPG250 and PG500 groups than other groups except for PG300 with the lowest values for control and PG400. Cows in all treatment groups were observed in heat and conceived earlier as well as had shorter open days and calving interval durations (p < 0.001) and low number of services per conception (p = 0.004) compared to control group with better results for PG500 and GPG250 groups. BHB level and percentage of cows suffered from subclinical ketosis at 7 DIM was significantly lower in GPG250, GPG150 and PG500 groups than control group. Cows in treatment groups had a significantly higher glucose level (p = 0.006) compared to control group. Regarding to economics, the control group showed the highest feed costs, insemination costs and total costs per animal. Additionally, control and PG400 groups had the highest cost per kilogram of milk from total and feed costs compared to other cows. PG300, PG500 and GPG250 groups recorded a greater net return and income over feed cost (IOFC). In conclusion, the continuous drenching of propylene glycol either individually or in combination with glycerol regimens for long duration (PG300, PG500, GPG150, GPG250) during the transition period of dairy cows may reduce the incidence of subclinical ketosis and consequently improve milk production, reproduction and economics compared to drenching for short duration (PG400).

The Influences of Various Housing Systems on Growth, Carcass Traits, Meat Quality, Immunity and Oxidative Stress of Meat-Type Ducks.

The present study aimed to investigate the effect of different housing systems on Pekin ducks. A total of 300-day old Pekin ducklings were randomly divided into four experimental groups; the first housed in a closed house (CH), the second in closed house with open yard (HY), the third group in closed house with swimming pool (CHSP) and the fourth in a closed house with swimming pool and yard (HYSP). Results indicated that the HYSP and CHSP produced higher body weight comparing to the other groups. However, the HYSP gave the highest body weight followed by CHSP then HY and CH. The same trend was observed regarding weight gain and feed-conversion ratio (FCR). Moreover, HYSP, HY and CHSP showed higher dressing percentage, breast muscles and thighs and lower abdominal fat than the CH group. Serum protein was significantly higher in HYSP and HY than that of the closed house. While, lipids, cholesterol and triacylglycerol were significantly lower in groups housed in HY than that of CH. Meat cholesterol and triacylglycerol reduced in groups reared in HY. Housing ducklings in yards and using swimming pools significantly improved the general immunity (phagocytic index and activity and differential leucocytes count), and also improved the oxidative stress parameters. In conclusion, results confirmed that housing ducks in a house supplied with yard and swimming pool can improve its productivity, carcass traits, meat quality, blood lipid profile, immunity and antioxidative status.

Respiratory and Reproductive Impairment of Commercial Layer Chickens After Experimental Infection with Gallibacterium anatis Biovar haemolytica.

The prevalence of Gallibacterium anatis in poultry production has increased over the last two decades. However, only a few studies have explored the pathogenicity of this bacterium in commercial layer chickens. This trial studied the aspects of the pathogenicity of a Gallibacterium anatis biovar haemolytica local Egyptian isolate (previously registered as strain B14 with GenBank accession no. KJ026147). We used 500 base pairs of a 16S ribosomal RNA gene and the 16S-23S ribosomal RNA intergenic spacer, partial sequence in an experimental infection trial in commercial White Shaver layer chickens aged 19 wk. The hens were divided into three groups of 40 birds each. The hens in Groups 1 and 2 were experimentally infected through the intranasal (IN) and intravenous (IV) routes, respectively, with a dose of 0.2 ml/bird containing 1.2 × 109 colony-forming units/ml. In contrast, Group 3 was kept as a noninfected control group. Both IN and IV infections resulted in a delayed egg laying for 1 wk and a significant (P ≤ 0.05) drop in egg production by 7.81% and 10.28% compared with the control group over 7 wk. Severe lesions in the form of hemorrhagic pneumonia, catarrhal tracheitis, ovarian follicle and oviductal regression, and septicemia were evident on necropsy, demonstrating the pathogenicity of G. anatis as a primary pathogen.