Intranuclear Inclusions in Cells Infected with Newcastle Disease Virus

Cells infected by Newcastle Disease Virus were observed to contain both intracytoplasmic and intranuclear inclusion bodies. Ultrastructurally, they consisted of twisted strands of about 18–20 nm diameter resembling nucleocapsids. The presence of these inclusions was detected irrespective of host cell or pathogenicity of the virus. In immunofluorescence and immunogold labelling experiments, these structures were tagged by an anti-P protein monoclonal antibody. In summary, we show that intracytoplasmic and intranuclear inclusion bodies, hitherto used as a taxonomic characteristic for the genus Morbillivirus of the Paramyxoviridae, also occur in a member of the genus Rubulavirus.     

Trait values of growth,carcass and meat quality in Wild Boar,Meishan and Pietrain pigs as well as their crossbred generations

The genetic diversity between European Wild Boar, Pietrain and Meishan and their crossbred generations are described on the basis of performance traits for growth, carcass composition and meat quality. Using the results of 1333 pigs, the highest growth rates were found in crossbred generations, indicating positive heterosis effects. In carcass composition, high meat content is associated with Pietrain and high fat content with Meishan alleles. Weights of organs were greatest in Wild Boar, the weight of the head was greatest in Meishan. Meat quality and stress resistance parameters point to superior gene effects in Wild Boar and Meishan. Crossbred animals of these genetically diverse pig sources generate the maximum variability for all traits, help to demonstrate the range of values for the specified breeds of pig and allow an efficient analysis of the genes influencing performance traits.     

Classical swine fever in The Netherlands 1997-1998: a description of organisation and measures to eradicate the disease

The central and regional organisation of the campaign to eradicate the CSF epidemic in the Netherlands in 1997/1998 is described. The main instruments used in the campaign were based on stamping-out and movement restrictions specified by the European Union. Additional instruments were used for the first time, namely, pre-emptive culling of contact and neighbouring farms, compartmentalisation of transport, monthly serological screening in established surveillance areas and supervised repopulation of all farms in the former surveillance zone. Two other measures, the killing of very young piglets and a breeding ban were introduced to reduce production in established surveillance zones. Several factors complicated the eradication campaign, for instance, the late detection of the first infection; artificial insemination as a source of infection; the organisation of pig farming in the Netherlands, with its highly concentrated production and dependence on the transport of stock from one unit to another; insufficient rendering capacity; decreasing sensitivity of clinical inspection; and extremely high costs.     

Effect of anthelmintic treatment on sexual maturation in prepubertal beef heifers

Heifers treated with ivermectin at weaning have been reported to reach puberty at a younger age and lighter weight than untreated heifers. We tested the hypothesis that heifers administered ivermectin would respond with earlier follicular development and a greater LH response to a 1-mg estradiol-17beta challenge (E2C) than untreated heifers. Fall-born Angus heifers (n = 32) were randomly assigned on 284 +/- 9 d of age (215.5 +/- 20.8 kg) to receive ivermectin (IVR) or albendazole (ALB), IVR + ALB, or to remain as untreated controls (CONT). Each group (n = 8) was housed separately in adjacent pens throughout the trial and managed to gain .8 kg/heifer on a ration containing 13.2% CP, 58.8% TDN, and 49.9% DM. The CONT heifers received an additional 2.27 kg/heifer of corn silage and 1.59 kg/heifer of corn daily to maintain ADG at comparable levels. Individual body weight was recorded weekly, and nematode eggs per gram (EPG) of feces were measured every 21 d. Ultrasonography was performed on alternate days starting 2 wk prior to E2C to characterize follicular wave patterns. Follicles were separated into classes (C1 [3 to 5 mm], C2 [6 to 9 mm], and C3 [10 mm]) and sizes (largest [LF], second [SLF], third [TLF], and fourth largest follicles [FLF]). The sizes of the regressing dominant follicle 1 (DF1) and the progressing dominant follicle 2 (DF2) were also determined. Serum concentrations of LH were determined from hourly jugular blood samples collected 8 to 24 h after injection of E2C. The IVR + ALB treatment group had more C3 follicles than ALB and CONT (P < .07). The IVR-treated heifers had larger TLF than ALB and CONT (P < .04). The IVR- and IVR + ALB-treated heifers had larger FLF and DF2 than ALB and CONT (P < .1). Least squares means for DF2 were 9.5 +/- .5, 8.0 +/- .4, 9.5 +/- .3 and 8.3 +/- .3 mm, for IVR, ALB, IVR + ALB and CONT, respectively (P = .02 for treatment effect). The E2C-induced serum LH concentration did not differ with respect to treatment. We conclude that heifers administered IVR display increased follicular development, supporting our earlier investigations regarding reduced age at puberty in heifers treated with IVR near weaning.     

Mycobacterium paratuberculosis isolated from fetuses of infected cows not manifesting signs of the disease.

Fetuses were obtained from 58 cows that were fecal culture-positive for Mycobacterium paratuberculosis, but were not manifesting signs of paratuberculosis. Fetal tissues from 5 of 58 cows were culture-positive for M paratuberculosis. All 5 culture-positive fetuses were from cows that were classified as heavy fecal shedders (5/28; 17.8%). Difference in prevalence of fetal infection between light (less than 70 colonies/tube) and heavy fecal shedders was significant (Fisher's exact test, P less than 0.05). Association was not evident between serologic status of the dam and prevalence of fetal infection. In infected cows without signs of paratuberculosis, fetal infection develops with lower frequency than previously reported for cows with clinical signs of the disease. In this study, fetal infection was found only in cows that were heavy fecal shedders.     

Differential leucocyte responses to various degrees of food restriction in broilers, turkeys and ducks.

1. White blood cell responses of broilers, turkeys and ducks were examined at regular intervals after being subjected to various degrees of food restriction. 2. Restricted-fed broilers showed increases in heterophil and basophil numbers, together with a corresponding decrease in lymphocytes. The heterophil/lymphocyte ratio was raised. There were no differences between broiler strains. 3. After only one week of feeding restricted diets, heterophils were significantly raised in selected and unselected 2-week-old ducks. At 21 weeks of age, those ducks receiving 50% of food required to achieve their ad libitum-fed body weight had raised heterophils. 4. Ducks receiving food to achieve 25% of ad libitum-fed birds produced a marked basophilia, but no heterophilia. 5. After two weeks of food restriction, turkeys responded with significant heterophil/lymphocyte ratios following two degrees of restricted feeding. 6. It was concluded that in some poultry, a heterophilia may be the response to mild to moderate stress but a basophilia may result after severely stressing birds.     

Genotype and treatment biases in estimation of carcass lean of swine.

Carcasses of 181 barrows, representing five genotypes, 1) H x HD, 2) SYN, 3) HD x L[YD], 4) L x YD, and 5) Y x L (H = Hampshire, D = Duroc, SYN = synthetic terminal sire line, L = Landrace, and Y = Yorkshire), and two levels of ractopamine (RAC) treatment (0 and 20 ppm) were completely dissected and the data were used to examine genotype and treatment (RAC) biases in estimation of fat-standardized lean weight and to evaluate accuracies and precisions realized by use of equations based on variables derived from different technologies. Independent variables used to establish regression equations represented technologies of direct carcass measurements, optical probe data, TOBEC (total body electrical conductivity) readings, and dissected (DHMLN) and fat-standardized (FSHMLN) ham lean. Genotype bias existed when any equation from a single technology was used and was minimized by combining FSHMLN with one TOBEC reading, carcass length, and the probe measurement of 10th rib fat depth. Large RAC biases appeared when equations from direct carcass measurements or optical probe data were used and were minimized by an equation using either DHMLN or FSHMLN. A practical equation with relatively high R2 value and small genotype and RAC biases were developed by combining TOBEC readings with direct carcass measurements of 10th rib fat depth and warm carcass weight.     

Evaluation of the protein quality of silaged corn ear products with different crude fiber contents

The assessment of the protein quality of silaged maize ear products was carried out on the basis of crude protein and amino acid analyses and of N balance measurings with growing pigs including comparative studies with maize corns and cereals. The differences found in the amino acid concentrations between the individual maize ear products could be verified on the basis of the analysed values of husks, cobs and corns. There were no significant differences in the parameters of total protein utilization (PNu, b-value) between the studied silages. The differing crude fibre content resulted, however, in reverse shifts in N excretion in faeces and urine, i.e. diminished protein digestibility was compensated by improved intermediary utilization.