Comparison of several enzymes between normal physeal and tibial dyschondroplastic cartilage of broiler chickens.

Normal physeal and dyschondroplastic cartilage of broiler chickens was examined for six enzymes by isoelectric focusing in thin-layer polyacrylamide slab gels. Acid phosphatase (ACP), esterase (EST), malate dehydrogenase (MDH), and peroxidase (PRX) were present in the normal physeal cartilage but not in the dyschondroplastic cartilage. Staining intensity of glucose-6-phosphate isomerase (GPI) and triose-phosphate isomerase (TPI) was reduced in the dyschondroplastic cartilage compared with that of the physeal cartilage.

Promoter and transcription of type X collagen gene in broiler chickens with tibial dyschondroplasia.

Type X collagen is produced exclusively in hypertrophic chondrocytes of the growth plate of the proximal tibiotarsus and is believed to play an important role during normal development from chondrogenesis to osteogenesis. Chondrocytes of chickens with tibial dyschondroplasia (TD) fail to attain full hypertrophy and the amount of type X collagen, being a marker of hypertrophy, is likely to be reduced. It is not clear whether transcriptional regulation is functional for expression of the type X collagen gene in TD birds.

Random amplified polymorphic DNA comparisons among broiler lines selected for incidence of tibial dyschondroplasia.

Lines selected for high (H) and low (L) incidence of tibial dyschondroplasia (TD) for eight generations and a randombred control (C) line of broiler chickens were fingerprinted by random amplification of genomic DNA mixed from 20 individuals of each line with 20 oligonucleotide primers. Among these 20 primers, 15 could distinguish the H from the L line, 14 the H from the C line, and 13 the L from the C line. Band sharing (BS), on the average over 20 primers, was .

Genetic correlations of tibial dyschondroplasia incidence with carcass traits in broilers.

Relationships among the incidence of tibial dyschondroplasia (TD) with 7-wk live BW, carcass component weights (CCW), and abdominal fat weight (AFW) were assessed using high and low incidence of TD lines developed by a seven-generation divergent selection experiment, along with a randombred control line. The incidence of TD exhibited negative genetic correlations with both BW (-.65 and -.

Chemicals used by the poultry industry.

The safe and effective use of chemicals within the live production phases of the poultry industry requires the implementation of integrated health programs. Chemical programs will vary with regard to phase, intended usage, and method and frequency of application. The term "chemicals" herein presented excludes drugs and non-nutritive feed additives, with primary emphasis on sanitation products (i.

Immunohistochemical detection of infectious bursal disease virus in formalin-fixed, paraffin-embedded chicken tissues using monoclonal antibody.

Immunoperoxidase and immunofluorescence techniques detected and localized infectious bursal disease virus (IBDV) in formalin-fixed paraffin-embedded sections of the bursa of Fabricius of experimentally and naturally infected chickens. The primary antibody was a monoclonal antibody that bound all IBDV serologic subtypes, including the GLS isolate. Both techniques were valuable in detecting IBDV.

Production and characterization of monoclonal antibodies against variant A infectious bursal disease virus.

Monoclonal antibodies (MAbs) were produced against a variant subtype of infectious bursal disease virus (IBDV) from Delaware variant isolate A (Var-A). Splenocytes from immunized mice were fused to myeloma cells, and antibody-producing hybridomas were screened by dot-blot enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence (IF) against the homologous isolate. Specificity of the MAbs was tested against viral isolates representing all six serologic subtypes of IBDV and three untyped IBDVs--GLS, Ark, and Miss--found in serotype 1 by dot-blot ELISA and IF.

Sample size required for various methods of assessing bone status in commercial leghorn hens.

A study was conducted to determine the appropriate sample size required for various methods used to assess tibial bone status in commercial Leghorn hens. The methods used were in vivo bone mineral content (BMC), in vivo bone density (BD), in vitro BMC, in vitro BD, tibia bone breaking strength (TBS), and percentage bone ash (BA). Dietary total P levels of .

Lysine supplementation of low-protein diets for broiler breeder males.

Two experiments were conducted to assess the impact of supplemental L-lysine HCl on N balance in broiler breeder males fed 8% CP corn-based diets (3,220 kcal MEn/kg; .15% supplemental DL-methionine; .24% basal lysine).

Performance of two male broiler breeder strains raised and maintained on various constant photoschedules.

The purpose of the present study was to examine the interaction of constant photoschedules and genetic background on performance of male broiler breeders. Day-old cockerels from two BW strains were placed on litter floors in light-controlled chambers. Light treatments (LT) (60 lx) consisted of 2, 4, 8, 16, and 24 h light/day.

Effects of dietary energy on semen production, fertility, plasma testosterone, and carcass composition of broiler-breeder males in cages.

One hundred-fifty broiler breeder males were raised to 17 wk of age in floor pens using standard procedures. The males were placed in individual cages at 18 wk of age in an environmentally controlled house and fed for recommended BW to 29 wk of age. At 30 wk of age, birds were randomly assigned to one of five dietary treatments.

Effects of ad libitum and restricted feeding on semen quantity and quality, body composition, and blood chemistry of caged broiler breeder males.

One hundred eighty, 16-wk-old, caged broiler breeder males were randomly assigned to one of three feeding treatments: 1) restricted feeding (RES), breeder-recommended levels minus 25%; 2) control feeding (CON), breeder-recommended levels; 3) full-fed (FF), ad libitum feeding. Each group received the same corn-soybean diet, with 15.5% CP and 2,878 kcal ME/kg feed.