Increasing incidence of anemia among clinically ill Georgia broilers: 1988-89 vs. 1990.

The incidence of anemia in clinically ill Georgia broilers climbed from 66.4% (324/488) during 1988-89 to 80.9% (531/656) during 1990. The incidence of polycythemia fell from 1.6% (8/488) during 1988-89 to 1.5% (10/656) during 1990. Specifically, compared with 1988-89, the 1990 incidence of anemia increased significantly in chicks at age 7 days (P = 0.0002) and 28 days (P = 0.05). We have no certain explanation for this shifting incidence of anemia in clinically ill Georgia broilers. Anemic chicks have plasma that contains virus particles with morphologic characteristics consistent with a virus (chicken anemia agent [CAA]) known to cause anemia in chickens. If CAA is the predominant etiology for anemia in clinically ill Georgia broilers, then our observation could be easily explained. The increasing rate of anemia could indicate a decline in broiler health over time.     

Evaluation of bee venom as a novel feed additive in fast-growing broilers

1. The present study was designed to evaluate purified bee venom (BV) as an alternative to antibiotics in broiler chickens. The experimental treatment diets were formulated by adding BV into a maize-soybean meal-based diet to give 0, 10, 50, 100, and 500 μg BV per kg of diet.

2. Dietary BV quadratically improved (P < 0.05) feed conversion ratio and increased body weight gain at 1–21 d as level in diet increased. Higher BV levels lowered relative weight of spleen (linear and quadratic, P < 0.05), bursa of Fabricius (quadratic, P < 0.05), and liver (linear and quadratic, P < 0.05) at 21 d of age. Relative breast meat yields were increased quadratically at 21 d and linearly at 35 d with supplementation levels. Dietary BV increased (linear and quadratic, P < 0.05) lightness (L*) value for meat at 21 d, decreased (linear, P < 0.05) ileal villus height and narrowed (quadratic, P < 0.05) width.

3. Dietary BV inclusion linearly increased the concentration of secretory immunoglobulin A (sIgA) on ileal mucosa at 21 d and decreased (quadratic, P < 0.05) nitric oxide contents in serum samples at 21 d and 35 d. Total short-chain fatty acids (SCFA) in caecal digesta were reduced with increasing venom in diets at 21 d of age. None of the serum parameters except for creatinine was affected by dietary BV.

4. It was concluded that dietary BV exhibited wide range of in vivo biological properties in broiler chickens and could be incorporated into feed to promote growth and animal health.     

Evaluation of Duroc- vs. Pietrain-sired pigs for growth and composition

Accurate evaluations of growth and composition traits enable better management decisions regarding genetic merit, feeding, and marketing. Sires from Duroc and Pietrain populations were used to produce crossbred pigs, which were evaluated for growth and composition traits. All parents were normal for the ryanodine receptor gene. Boars from each breed were mated to either Yorkshire or F1 Yorkshire-Landrace females with 307 offspring evaluated from birth through 26 wk of age. No significant differences between sire breeds were seen for pig BW from birth through 10 wk of age. Body weight, 10th rib backfat (BF10), last rib backfat (LRF), and loin muscle area (LMA) were serially measured at 10, 13, 16, 19, 22, 24, and 26 wk of age. At 26 wk of age, Duroc-sired progeny were heavier (143.4 vs. 132.7 kg, P < 0.001), had more BF10 (27.1 vs. 23.7 mm, P < 0.001) and LRF (21.2 vs. 19.2 mm, P < 0.001), but had similar LMA (46.4 vs. 47.1 cm2) compared with Pietrain-sired progeny. Mean feed efficiency did not differ between breed of sire in any period of the study. Duroc progeny had a greater ADG (980.1 vs. 892.3 g/d, P < 0.001) from 10 to 26 wk of age than Pietrain-sired pigs. Composition traits of fat-free total lean (FFTOLN), total fat tissue (TOFAT), empty body protein (EBPRO), and empty body lipid (EBLIPID) were calculated. Random regression animal models with polynomial regression on week on-test were fitted to BW, BF10, LRF, LMA, FFTOLN, TOFAT, EBPRO, and EBLIPID from 10 to 26 wk of age. Duroc-sired barrows tended to grow faster but with more fat tissue, and Pietrain-sired gilts were slower growing but leaner, whereas Duroc-sired gilts and Pietrain-sired barrows were intermediate for growth and backfat measures. Serial heritability estimates generally increased from 10 to 26 wk of age with ranges as follows: BW (0.05 to 0.39), BF10 (0.13 to 0.76), LRF (0.11 to 0.79), LMA (0.05 to 0.73), FFTOLN (0.07 to 0.16), TOFAT (0.19 to 0.45), EBPRO (0.02 to 0.55), and EBLIPID (0.12 to 0.60). Pigs sired by Duroc and Pietrain boars had similar lean tissue growth but achieved it through different mechanisms.     

Evaluation of efficacy of Vero cell-adapted,thermostable Newcastle disease vaccine in broilers

The main theme of this project was to develop a Vero cell-adapted, thermostable NDV I-2 vaccine and evaluate its efficacy against challenge infection. For this purpose, serial passages of virus were done in Vero cell line up to 13 times and after each passage samples were subjected to heat treatment at 56°C for 40 min. After 13 passages, the virus was completely adapted on Vero cell line and cytopathic effects were observed, including syncytial formation, rounding, degeneration, and detachment of cells. Hemagglutination and infectivity titers showed that the virus was thermostable after each passages in Vero cell line. One-day-old broiler chicks (Group 1) were vaccinated orally with thermostable NDV I-2 vaccine. A commercially available thermolabile NDV LaSota was used in Group 2 used as positive control. NDV I-2 vaccine produced maximum % inhibition migration at d 6 (50%) as compared with LaSota ND vaccine (i.e., 32%). On encounter with virulent NDV I-2, 100% safety was accomplished in group 1 and 60% in case of group 2. All the birds in the control negative group had died. This study led to the conclusion that thermostable Vero cell adapted I-2 strain vaccine resulted in better immunization in broiler birds than obtained by the use of commercially available thermolabile vaccines.     

Analytical determination and pharmacokinetics of major metabolites of carbasalate calcium in broilers following oral administration

As a newer anti-inflammatory agent, carbasalate calcium is used in various animal species. In this study, the pharmacokinetics of carbasalate calcium was investigated in broilers. Broilers, with body weight of 2.0 ± 0.3 kg, were administrated carbasalate calcium soluble powder at a single dose of 40 mg/kg body weight orally. The plasma concentrations of its metabolites, aspirin (ASA), salicylic acid (SA) and gentisic acid (GA) were determined by LC-MS/MS method and the pharmacokinetic parameters were calculated by noncompartmental analysis. After oral administration of carbasalate calcium, the plasma drug concentration for ASA, SA and GA reached a peak (C(max) ) of 8.88 ± 1.31, 42.6 ± 4.62 and 10.1 ± 2.16 μg/mL at 0.170, 2.00 and 2.00 h, respectively. The terminal half-life (t(1/2λz) ) of ASA, SA and GA was 11.2 ± 8.04, 23.7 ± 17.1 and 28.6 ± 4.90 h, respectively. In conclusion, analytical method for the quantification of ASA, SA and GA in plasma in the broilers was developed and validated. In broilers, carbasalate calcium is quickly metabolized in ASA and ASA is rapidly converted to SA and one of the metabolites of SA is GA.     

Reproduction and treatment of necrotic enteritis in broilers.

A change in ration from one containing 50% fish meal to a standard chick starter containing 10(8) Clostridium perfringens/g of feed resulted in the production of necrotic enteritis in 2-week-old broiler chicks. Lincomycin added to the inoculated ration at a concentration of 20 g/907.2 kg significantly reduced mortality in the chicks. Inoculation of broth cultures of C perfringens directly into the duodenum, using a surgically inserted tetrafluoroethylene resin tube, indicated a relationship existed between the number of C perfringens inoculated and the gross lesions. The disease could be consistently produced by this technique.     

Comparison of serum biochemical profiles of male broilers with female broilers and White Leghorn chickens.

Male broiler chickens were compared to female broiler chickens and male White Leghorns with respect to a 15-parameter serum biochemical profile at 9, 20, 30 and 42 days of age in order to determine which, if any, of the parameters tested might be useful in the identification of birds susceptible to sudden death syndrome. In comparison to female broilers, male broilers had significantly lower (p less than 0.01) total protein levels at 20 days of age and significantly higher (p less than 0.01) cholesterol levels at 30 days of age. Compared to male White Leghorns, in which sudden death syndrome has not been reported, male broilers had significantly lower (p less than 0.01) levels of cholesterol and creatinine at nine days of age, total protein at 9 and 20 days of age and albumin at 20 days of age and significantly higher (p less than 0.01) levels of potassium at nine days, uric acid at 9, 20 and 30 days, lactate dehydrogenase at 20, 30 and 42 days and cholesterol at 30 days of age.     

Evaluation of Duroc- vs. Pietrain-sired pigs for carcass and meat quality measures

Crossbred progeny sired by either Duroc or Pietrain boars, normal for the ryanodine receptor gene, were evaluated for carcass composition and meat quality. Boars from each breed were mated to Yorkshire or F1 Yorkshire-Landrace females. A total of 162 off-spring was evaluated for carcass and meat quality traits at a common age (approximately 26 wk of age). Duroc-sired progeny had heavier (108.0 vs. 103.0 kg, P < 0.001) and longer carcasses (86.9 vs. 84.8 cm, P < 0.01), whereas Pietrain-sired pigs had less backfat at the first rib (44.6 vs. 47.7 mm, P < 0.01), last lumbar vertebrae (20.9 vs. 23.0 mm, P < 0.05), and 10th rib (23.0 vs. 25.5 mm, P < 0.01). No difference between Pietrain and Duroc progeny was detected for fat depth at the last rib (27.8 vs. 28.8 mm, respectively). Pietrain progeny had a higher percentage of lean at slaughter (52.6 vs. 50.7, P < 0.05) and higher dressing percentage (74.0 vs. 73.1, P < 0.01). Primal cut weights were collected with Pietrain progeny having a greater percentage of carcass as ham (23.0 vs. 22.4, P < 0.01) and loin (21.6 vs. 21.2, P < 0.05), whereas Duroc progeny had a higher percentage of belly weight (12.0 vs. 11.7, P < 0.05). Percentages of Boston butt (8.8 vs. 9.0) and picnic shoulder (9.9 vs. 9.9) were similar for Duroc vs. Pietrain progeny. Total weight of these five primal cuts, as a percentage of carcass weight, was higher for Pietrain progeny (75.2 vs. 74.3, P < 0.01). With heavier carcass weight, Duroc progeny had greater primal cut weights as a function of age. Subjective meat quality scores for color, marbling, and firmness (1 to 5 scale) were more favorable for Duroc-sired progeny. Furthermore, chops from Duroc progeny had higher 24-h pH (5.53 vs. 5.48, P < 0.001) and Minolta a* (17.33 vs. 17.04, P < 0.05) with less percentage drip loss (2.88 vs. 3.80, P < 0.001). No differences were detected between Duroc- and Pietrain-sired progeny for Minolta L* (54.77 vs. 55.37) or b* (7.58 vs. 7.58) objective color scores, percentage cooking loss (28.63 vs. 29.23), or Warner-Bratzler shear force (6.94 vs. 7.11 kg). Both sire breeds have beneficial traits that can be utilized in commercial pork production and merit further study.     

Fumonisin mycotoxicosis in broilers: performance and pathology.

Fusarium moniliforme culture material containing fumonisin B1 at 300 mg/kg was incorporated into a broiler starter ration and fed ad libitum to 1-day-old broiler chicks for 2 weeks in two experiments. Clinical features of the disease produced included diarrhea, a 19% reduction in body weight, a 30% increase in relative liver weight, and a worsening of feed conversion by 20 points at 2 weeks of age. Histologically, chicks fed fumonisin had multifocal hepatic necrosis, biliary hyperplasia, muscle necrosis, intestinal goblet-cell hyperplasia, and rickets. Simultaneous feeding of 0.5% aluminosilicate had no effect on the clinical disease or lesions. The clinical disease and lesions induced mimicked those of a viral enteritis.     

Evaluation of a rapid method of determination of plasma fibrinogen in swine.

An evaluation was made of a rapid semiautomated method for determining fibrinogen level in swine plasma. This method, referred to as thrombin time method or fibrometer method, is based on the principle that when thrombin is added to suitably diluted plasma, the time of clotting is linearly related to the fibrinogen concentration. The linear regression model for the standard curve prepared using swine plasma had an r value of 0.998. A comparison between the fibrometer and the Grannis methods done on 189 swine plasma samples showed good correlation between these two mehtods (r value 0.847). It was concluded that although the fibrometer method may not be as precise as the Grannis method, it would still be acceptable for clinical use in swine.     

The determination of the rate of protein synthesis of the whole body of growing broilers

The purpose of the investigations was to prove a method, developed for monogastric mammalians, based on a 3-compartment-model and assuming a proportional growth of the pools of total N, whether it is applicable to growing poultry. The tracer, 15N-L-lysine, was given quasi-continuously for four days. In this time and in the following period of five days without tracer intake, the 15N-excretion in the urine was measured. The average of the live weight of the broiler cockerels was 1724 g. The animals were obliged to be colostomized to sample the urine. Using the fluxes of lysine, the calculation of the whole body protein synthesis rate yields 64.1 g/d. The protein degradation rate yields 54.4 g/d. The adequate values of the fractional rates of protein synthesis and -degradation for the whole body (without feathers) were 23.3% respectively 19.8%. By this it is clearly shown, that the applied method gives real dates of the parameters of the N-metabolism for growing broilers, which are in the range of values for muscle proteins and proteins of the whole body of growing poultry, published by other authors.     

Continuous disinfection as a means to control infectious diseases in poultry. Evaluation of a continuous disinfection programme for broilers

A full continuous disinfection programme, consisting of disinfection during cleanout of poultry houses prior to placement of chickens, disinfection of the drinking water and spray disinfection of the birds during production was evaluated in broilers under experimental condition as well as under field conditions. Under controlled conditions, the experimental design consisted of three groups, two of which were control groups. Each group comprised 300 chickens. In one of the control groups, no disinfection of the pens was undertaken prior to the placement of the chickens. In the other control group, disinfection of the pens prior to placement of the birds was carried out using a glutaraldehyde-based product. In the test group, disinfection prior to placement was done. The drinking water of these birds was treated continuously and the birds were sprayed with a non-toxic disinfectant during production. Production parameters, such as growth rate, feed conversion ratio and feed consumption, of the birds in the three groups were monitored. In addition, all mortalities in the different groups were recorded and classified into diseases of an infectious nature, non-infectious nature and unknown category. Bacterial counts were also done on a weekly basis from the different pens. In this experiment, it was shown that the full continuous disinfection programme resulted in a lower number of mortalities caused by infectious agents as well as a reduction in the bacterial counts in the pens treated with the full continual disinfection programme. The full continuous disinfection programme was also tested on a commercial poultry farm in the Northern Cape Province of South Africa. Two production houses of 3,500 birds were randomly selected as test houses for the full continuous disinfection programme. Another similar house, which received day-old chicks from the same batch as the other two houses, was selected as the control house; it received the routine disinfection procedure prior to placement of the chicks. During the course of this experiment, a severe outbreak of Newcastle disease was experienced on this farm. It was demonstrated that, in the face of this severe challenge, the full continuous disinfection programme controlled the spread of the disease in both the houses where it had been applied at a stage when in every other house (including the control house) on the farm birds were suffering very high mortalities.     

肉鸡大肠杆菌病发病情况报告

鸡大肠杆菌病是由埃希氏大肠杆菌的某些致病菌株所引起的一类疾病。其特征是引起鸡的心包炎、肝周炎、气囊炎、腹膜炎、滑膜炎、大肠杆菌病肉芽肿、败血症、肠炎、脑炎等多种临诊病型。随着我国集约化养鸡业的不断发展，饲养密度的增加，鸡的大肠肝菌病呈明显的上升趋势，给养鸡业造成了巨大的经济损失。笔者2004年在禽病诊治工作中，遇到两起肉鸡出现高致死率的病例，经过临床及实验室诊断，证明为鸡大肠杆菌病。现将发病情况报告如下：