No description available.

Fertility of Broiler Breeders (BBs) has been researched over many years with inconclusive findings. Genetic selection and improvements in growth traits have had negative effects on fertility of BB. One explanation is related to overweight birds, resulting in the inability of birds to copulate successfully, with no cloacal contact. The requirements of CP for egg production in BB females have been quantified, but there is less literature on how CP affects fertility in male BBs. The objective of this experiment was to investigate the effects of feeding BB males different dietary CP intakes (10.4, 12.4, 14.2, 17.8, 19.3 and 20.1 g CP/bird/day) on fertility in flocks with natural mating and in birds that were artificially inseminated (AI). Results showed that birds consuming 10.4 and 12.4 g CP/bird/day resulted in weight loss (between 24.9 and 23.6% and 26.5 and 22.4% below target BW) over the 29 weeks of the experimental period in both natural mating and individual pens respectively. Intakes of higher protein content (17.8- 20.1 g CP/bird/day) however resulted in BW gain over the experimental period. Hatch percentage across all CP intakes throughout the duration of the study was found to be high, ranging between 75- 100 and 80-95 % in AI and naturally mated birds respectively, and not affected by CP intakes. Similar results for predicted fertility using the methods published by Brillard & Antoine (1990) and Wishart (1997) were found; however Brillard & Antoine (1990) is more lenient requiring less outer perivitelline layer (OPVL) sperm/mm2 to pronounce an egg fertile. Improved fertility predictions could have been made by using examination of inner perivitelline layer (IVPL). There was a tendency for a superior response in predicted fertility from birds with a protein intake of 14.2 g CP/bird/day. This intake also least affected the BW of the male birds and thus 14.2 g CP/bird/day can be recommended for optimal BB male performance. / Thesis (M.Sc.Agric.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.

Infectious bursal disease virus (IBDV) is a chicken pathogen that infects the bursa of Fabricius, an organ involved in the development of the immune system in chickens. Infection by the virus leads to destruction of the bursa and immunosuppression. Infection by virulent strains may result in mortality. Current methods to combat the virus involve the use of vaccines. These are usually a mixture of live attenuated and oil inactivated virus. Variant strains of the virus are able to escape the vaccine-generated antibodies. In addition, the vaccines result in damage to the bursa. Identification of a receptor for IBDV could result in the development of either treatment for the virus or superior vaccines by interfering with the attachment of the virus to host cells. Several methods for identifying IBDV binding proteins from the membranes of cells from the bursa of Fabricius were examined. Affinity chromatography of IBDV binding proteins with a matrix consisting of IBDV cross-linked to Sepharose 4B allowed separation of a number of virus binding proteins. In contrast, virus overlay protein blot assay (VOPBA) and reversible cross-linking with 2-iminothiolane proved less; conclusive. Predominant proteins in the affinity-separated fraction were of 40 and 32 kDa. These were further examined by N-terminal amino acid sequencing of the whole protein and N-terminal sequencing of peptides produced by endoproteinase Lys-C digestion of the protein respectively. The 40 kDa protein showed homology with human synovial stimulatory protein involved in the formation of autoantibodies in rheumatoid arthritis. Virus was also shown to bind to a 440 kDa protein complex. This 440 kDa protein complex appeared to consist primarily of a 40 kDa protein when examined by reducing Tris-Tricine SDS-PAGE. Analysis of bursal membrane proteins by Western blots using sera from rheumatoid arthritis patients revealed interactions between several IBDV proteins and the antibodies from rheumatoid arthritis patients. Using serum from one of the five patients showed a strong interaction at approximately 80 kDa and a weaker interaction at approximately 40 kDa. This may indicate an immune reaction between a chicken homolog of the synovial stimulatory protein and antibodies in rheumatoid arthritis sera. The 32 kDa protein showed homology to a Pseudomonas fluorescens protein. A section of this sequence was amplified by PCR from chicken DNA and RT-PCR from chicken RNA using degenerate primers constructed from the established N-terminal amino acid sequences and chicken codon usage tables. The fragment produced upon amplification from chicken DNA and RNA did not correspond to the predicted size of 177 bp. In contrast, when the RT-PCR product was heated and snap cooled before examination by agarose gel electrophoresis, the product consisted of two fragments, one of approximately 400 bp in size and one of approximately 200 bp in size. The establishment ofthe 40 and 32 kDa chicken bursal membrane proteins as possible receptors for the virus could allow for the development of vaccines and/or treatment strategies for the virus. Treatment strategies or vaccines would be based on blocking of the interaction between IBDV and chicken host cells. Peptide mimics of the epitopes involved in such interactions could possibly achieve this. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2000.

Marek's disease (MD) is a highly contagious and economically important disease in the poultry industry. It is caused by an oncogenic avian herpes virus. The ability of the virus to evolve into new strains is a continual threat. Vaccination, proper management and genetic resistance are required to completely eliminate the pathogen. The discovery of several markers associated with MD resistance shows that genetic selection for resistance is feasible. Our objective was to identify markers in QTL regions that are associated with MD viraemia. The markers analysed were in the ODC gene, the GH gene and two chemokine genes, all of which are candidate genes for immune responsiveness. A database in a commercial strain of White Leghorn chickens was created. Heterozygous males and homozygous females were identified. The offspring were challenged with MD virus and spleen and thymus samples were collected six days after infection. The viral titre was quantified using competitive PCR. The data was analysed using non-parametric statistics. We found that the paternal alleles of a Hindlll RFLP in the ODC gene were associated with differences in MD viraemia in one of the six sire families analysed. In addition, a Sacl RFLP located in the GH gene also segregated for alleles, which affected MD viraemia. The analysis of the ODC gene was extended to include a second RFLP at a Msp\ site. Together with the Hindlll RFLP it defines three different haplotypes. One genotypic class AB (Hindlll (+/-), Mspl (+/+)) was associated with low vireamia in the thymus and the genotype BB (Hindlll (-/-), Mspl (+/+)) with high viraemia in the spleen. The result suggests that genetic variations in the ODC and GH gene affect MD viraemia. However, we cannot exclude that the observed effects might be due to linkage disequilibrium with adjacent genes. In the latter case, chromosome 3 and chromosome 1, which harbour the ODC and GH gene respectively, must segregate for regions that affect viraemia. The markers identified in this analysis can be used in marker assisted selection.

The potential of lignin and mannanoligosaccharides (MOS), as alternatives to antibiotic growth promoters was evaluated in broilers. Dietary treatments included: (1) negative control (CTL-, antibiotic free); (2) positive control (CTL+, 11 mg/kg virginiamycin); (3) MOS (diet 1 + Bio-Mos: 0.2% to 21 d and 0.1% thereafter); (4) LL (diet 1 + 1.25% Alcell lignin); (5) HL (diet 1 + 2.5% Alcell lignin). Bodyweight and feed conversion were not different when broilers were fed the CTL+, MOS, LL or HL diet. Birds fed MOS or LL had increased jejunum villi height (P < 0.05) and greater goblet cell number per villus (P < 0.05) when compared to those fed the CTL+ diet. MOS and LL increased (P < 0.05) the cecal populations of Lactobacilli and Bifidobacteria when compared to CTL+ fed birds. However, Lactobacilli and Bifidobacteria loads were lowest (P < 0.05) in birds fed the CTL+ or HL diet. Litter E. coli load was reduced (P < 0.05) when birds were fed MOS than when fed the CTL+ diet, but comparable to LL or HL fed birds. In birds challenged with pathogenic strains of E. coli (O2 and O88 serotypes) and fed the MOS or HL diet, the cecal population of total E. coli was lower (P < 0.05) than those fed the CTL+ diet; LL fed birds tended to have lower E. coli load than CTL+ fed birds. In summary, birds fed the MOS or LL diet had comparative advantage over CTL+ fed birds as evidenced by increased cecal populations of Lactobacilli and Bifdobacteria, increased villi height and greater goblet cell number in the jejunum, lower E. coli load in the litter, and lower cecal population of E. coli after an in vivo challenge with pathogenic strains of E. coli. Therefore, MOS and lignin could be regarded as natural alternatives to antibiotic growth promoters in poultry production. / Key words. Antibiotics, mannanoligosaccharides, lignin, gut health, broilers.

A study was conducted to examine the response to feeding flaxseed (FS) and probiotics on plasma and egg yolk cholesterol and plasma fatty acid profile in laying hens. A total of 576 Single Comb White Leghorn hens (SCWL) at 26 weeks of age were fed diets containing 15% FS and a corn-soybean meal diet (C) supplemented with and without ferlac 25 (F25) or Lactobacillus acidophilus (LA). Feed consumption was significantly (p < 0.05) increased by FS supplemented with both F25 and LA. Dietary treatments had no significant (p > 0.05) effect on feed conversion. Egg production was significantly (p < 0.05) higher among the FS probiotic supplemented diets and significantly (p < 0.05) lower for dietary FS supplemented with LA. However, egg yolk weight did not respond to dietary treatments (p > 0.05). Body weight was significantly low for all FS fed groups. Shell thickness was not statistically significant (p > 0.05) among experimental treatments, while haugh units were significantly (p < 0.05) higher for FS group supplemented with LA. Probiotic supplementation significantly (p < 0.05) reduced plasma cholesterol (CHL) from 161mg/dL in C diet to 117mg/dL in probiotic supplemented groups. Plasma triglycerides (TG) were significantly (p < 0.05) reduced from 2.8g/dL in FS to 1.9g/dL in probiotic supplemented groups while egg yolk CHL was significantly (p < 0.05) reduced by probiotic supplementation on FS treatments from 14.04mg/g in FS fed group to 10.16mg/g in LA supplemented FS group. Fatty acids profile in the egg yolk responded significantly (p < 0.05) to dietary treatments. FS treatments with and without probiotic supplementation significantly reduced C18:1 o-9 by 12%; while the PUFA families (o-3 and o-6) were significantly (p < 0.05) increased in FS fed group by 93% and 18%, respectively. C20:4, o-6 was significantly reduced from 6.6mg/g in the C group to 3.96mg/g in Fs groups. (Abstract shortened by UMI.)

No description available.

Experiments were conducted to determine the optimal conditions for tail-end dehulling of canola meal (CM) and the production of high-protein, high-energy and low-fiber CM. The use of sieves from 250-600µm resulted in the production of dehulled fractions 1 and 2 from three different types of CM. On average, and in comparison with their parent meals, the dehulled fractions 1 and 2 contained less dietary fiber (19.4 and 22.9 vs. 27.5%) and more protein (44.5 and 43.1 vs. 40.1%), respectively. Growth performance experiments were conducted with broiler chickens and weaned piglets fed diets containing dehulled CM fractions. In the broiler chicken trial, no significant differences for feed intake, BWG and feed efficiency were observed, indicating that CM and its low-fiber fractions could replace SBM in the broiler pre-starter diets at a lower cost. In the swine experiment, a beneficial effect of dehulling on final body weight and feed efficiency was observed.

A model of growth and plasmid transfer between strains of Escherichia coli and Salmonella typhimurium was developed with reference to the literature. This was the organising principle for the collection of a complete set of in vitro life history parameters of one S. typhimurium and one E. coli strain. In the course of estimating these parameters two results of note were obtained. Fits of the Lotka-Volterra competition model were obtained for data on S. typhimuiurm growing in competition with E. coli. The first noteworthy discovery was the failure of this model to account for several characteristics of growth of these strains under competition. The growth rates of plasmid-bearing and plasmid-free strains were obtained. The second main result came from examination of the results of the growth rate data, which revealed that the cost to S. typhimuiurm 576 of bearing the resistance plasmid was low (4%). The model was also used to simulate the effect of antibiotic dose on the density of the donor, recipient and transconjugant populations over time. These simulations predicted that there would be a convex relationship between antibiotic dose and transconjugant density (i.e. that the density would first rise, then fall, with increasing dose). Following from this result, laboratory experiments and in vivo experiments in chickens were directed towards obtaining information on the relationship between these two variables. This convex relationship was not demonstrated within a single experiment, although some experimental environments produced an increase in transconjugant density with dose, and others, a decrease. Few transconjugants were formed in vivo. In order to investigate the low cost of resistance and low rate of in vivo transconjugant production, cost of resistance and plasmid transfer rate of this plasmid in several strain combinations of E. coli and S. typhimuiurm was evaluated.

Darbo tema : Lesalų, papildytų nesmulkintais kvietrugiais, įtaka viščiukų broilerių produktyvumui, virškinimo trakto išsivystymui bei virškinimo procesams Darbo tikslas: įvertinti viščiukų broilerių produktyvumą, virškinimo trakto išsivystymą bei virškinimo procesus, lesalus papildžius nesmulkintais kvietrugiais. Darbo uždaviniai: 1) ištirti lesalų papildytų nesmulkintais kvietrugiais įtaką viščiukų broilerių produktyvumui, lesalų sąnaudoms 1 kg priesvorio gauti ir išsaugojimui; 2) ištirti lesalų papildytų nesmulkintais kvietrugiais įtaką viščiukų broilerių virškinimo trakto išsivystymui; 3) ištirti lesalų papildytų nesmulkintais kvietrugiais įtaką viščiukų broilerių virškinimo procesams (žarnų turinio pH, SM, amoniakiniam azotui ir kt.). Tyrimu rezultatai ir išvados: Tiriamųjų grupių kombinuotasis lesalas 1–7 amžiaus dienomis buvo papildytas skirtingais nesmulkintų kvietrugių kiekiais: I-osios tiriamosios grupės lesaluose neskaldyti kvietrugiai sudarė 4 %, II-osios – 6 %. Nuo 8 iki 35 amžiaus dienos viščiukai broileriai buvo lesinami tarpiniu lesalu. Nuo 8 iki 21 amžiaus dienos viščiukų broilerių lesalai buvo papildyti skirtingais nemulkintų kvietrugių kiekiais – pirmos tiriamosios grupės lesaluose nemulkinti kvietrugiai sudarė 8 %, antros tiriamosios – 12 %, o nuo 22 iki 35 amžiaus dienos – pirmos tiriamosios grupės lesaluose nesmulkinti kvietrugiai sudarė 15 %, antros tiriamosios – 20 %. Nuo 36 iki 40 amžiaus dienos viščiukai broileriai buvo lesinami lesalu, kuriame... [toliau žr. visą tekstą] / The topic: The effect of having hole triticale grains complemented feed on chicken broilers productivity, the development of digestine system and digestine processes. The objective of the research – to investigate broiler chicken productivity, gastrointestinal development and digestive processes by adding whole triticale supplement into the feed. Tasks of the research: 1) To investigate the effect of having whole triticale supplemented feed for broiler chickens productivity, aiming to gain and maintain 1kg broiler weight. 2) To investigate the effect of having whole triticale supplemented feed on broiler chickens digestive tract occurrence. 3) To investigate the whole triticale supplemented feed influence on broiler chickens digestive processes (intestinal pH, DM, ammonia nitrogen and etc.). Results and conclusions: Two different groups of chickens were given whole triticale supplemented feed of various proportions during the first seven days of nestling. The third group received a normal diet. The first group of broiler chickens was fed with the feed containing 4% of whole triticale, while the second received 6%. During days 8 to 21 of broilers age, the supplements of whole triticale in the first group grown up to 8%, while in the second group by 12%. During days 22 to 35 of broilers age, the first test group was fed a diet of whole triticale going up to 15% and the second group - 20%. From 36th to 40th day of chickens age, broilers were fed a diet that contained none... [to full text]