Veterinary Science Research

The Influence of Newcastle Disease Virus Major Proteins on Virulence

Guozhong Zhang, Jia Xue, Xiao Li — Mon, 13 Dec 2021 00:00:00 +0800

The Newcastle disease virus (NDV) negative-strand RNA genome contains

six genes. These genes encode nucleoprotein (NP), phosphoprotein (P),

matrix protein (M), fusion protein (F), hemagglutinin-neuraminidase (HN),

and RNA-dependent RNA polymerase (L) proteins. The six proteins affect

the virulence of NDV in different ways, but available information on the

six proteins is disparate and scattered across many databases and sources.

A comprehensive overview of the proteins determining NDV virulence is

lacking. This review summarizes the virulence of NDV as a complex trait

determined by these six different proteins.

Survey on Avian Malaria Parasites in Village Chickens (Gallus gallus domesticus) in Gombe Local Government Area, Gombe State, Nigeria

Wed, 22 Dec 2021 00:00:00 +0800

Reports of avian malaria parasites in village chicken in Nigeria generally remain fragmentary and scarce. The study was conducted in Gombe Local Government Area of Gombe State, Nigeria to investigate avian malaria parasites in Village Chickens (Gallus gallus domesticus) and to determine the risk factors associated with the prevalence of the haemoparasites. A total of 530 village chickens blood samples were obtained from apparently healthy village chickens' brachial veins using sterile 2mls syringes and 23 gauge needles. Thin blood smear was made from each blood sample, and Giemsa stained and examined for the presence of avian haemoparasites under an electro-microscope. The result indicates 23.8% overall prevalence rate of three species of avian malaria parasites consisting of Plasmodium, Haemoproteus and Leucocytozoon species.Plasmodium spp. has the highest prevalent rate of 13.0% followed by Haemoproteus spp. (5.1%), mixed Plasmodium spp. + Haemoproteus spp. (4.9%) infection and Leucocytozoon spp. (0.8%). Prevalence of avian malaria parasites was significantly higher in cocks compared to hens (p < 0.05), as well as higher in adults compared to growers chickens (p < 0.05). This study also showed a higher prevalence of avian malaria parasites during the rainy season compared to the dry season of the study period. It was concluded that haemoparasites of Plasmodium, Haemoproteus and Leucocytozoon species that occur in both single and mixed infections are prevalent among village chickens that are apparently healthy in Gombe Local Government Area of Gombe State, Nigeria.

Investigation of Two Precipitation Methods for Extracting Immunoglobulin Y (IgY) from Egg Yolks

Tran Thi Quynh Lan, Tran Trong Kha — Mon, 27 Dec 2021 00:00:00 +0800

Two groups of hens (control and immunization group) were arranged in an experimental design with an immunization schedule of 3 injections of BSA antigen. IgY antibodies were extracted from egg yolks by two precipitation processes (chloroform and polyethylene glycol precipitates) and quantified using a standard curve of protein concentration. The purification of IgY

was confirmed by SDS-PAGE. Total protein extracted from egg yoks were less contaminated with yellow pigments (lutein and zeaxanthin) by using chloroform precipitate. The 2nd week post-immunization, IgY concentration increased respectively to 3903 ± 726 μg.ml-1 (chloroform extraction process) and 2937 ± 294 μg.ml-1 (PEG extraction process) (P < 0.01). After 3rdimmunization, IgY level obtaining from in immunization group extracted by chloroform process (6633 ± 1166 μg.ml-1) increased 2.7 times higher than that in control group (2482 ± 414 μg.ml-1). Whereas IgY concentrations obtained from PEG extraction process were not significantly different between the experimental group and control group. Chloroform and PEG precipitation methods had the same protein profile on the SDSPAGE. IgY antibody was identified by the presence of bands corresponding with IgY heavy chain (67-70 kDa) and IgY light chain (25 kDa) for both precipitation processes.

Economic Impacts of Clinical and Sub Clinical Mastitis on Dairy Farms

Amjad Islam Aqib, Afshan Muneer, Muhammad Shafeeq, Nimra Kirn — Wed, 29 Dec 2021 00:00:00 +0800

Studies have reported on the economic impacts of clinical and subclinical mastitis on dairy farms. Bovine mastitis is a disorder that affects dairy farms and has a major economic impact. Most of the economic losses are the result of mastitis. Mastitis is an invasive infection that is among the most numerous and highly complicated infections in the dairy sector. Mastitis is one of the most expensive diseases in terms of production losses among animal diseases. Mastitis reduces milk production, changes milk composition, and shortens the productive life of infected cows. Farmers must concentrate on avoiding mastitis infection whilst putting in place and following a mastitis control programed. Bovine mastitis, the most significant disease of dairy herds, has huge effects on farm economics. Mastitis losses are due to reduced milk production, the cost of treatments, and culling. Major factors related to low milk yield could be low genetic potential as well as poor nutritional and managerial approaches. Most of the losses are related to somatic cell count (SCC), which is characterised by an increase in the percentage of milk. Culling costs are the costs of rearing or buying a replacement animal, mostly heifers. Overhead impacts include the replacement animals' lower milk supply effectiveness. The expense of replacing animals prematurely due to mastitis is one of the most significant areas of economic loss.

Comparison of locomotion problems and its economic impact on Cobb and Ross broiler strains

Fri, 14 Jan 2022 00:00:00 +0800

The rapid weight gain and fast muscle growth due to intense genetic selection and improved nutrition for additional breast muscle in broiler commercial strains affect chickens health. In order to compare the main locomotive problems in broilers of Cobb and Ross strains, two pens from a commercial farm in Veracruz, Mexico were used. The first pen housed 16,500 males and 16,500 females of Cobb strain and the second one 16,500 males and 16,500 females of Ross strain. Chicks were checked for locomotion problems from day one until their sale. Animals with problems were recorded and necropsies were performed to identify the pathology. Out of 1406 animals with locomotive problems (2.13% of the total), 58.9% were Cobb and 41.1% Ross (P <0.05). The frequency of locomotive problems was 2.51% for Cobb and 1.75% for Ross. Most common individual lesions were osteochondrosis (38.61%), inflamed joints with purulent contents (37.13%), and valgus (19.65%). Locomotive problems appeared since the first week, but its number increased as birds gained weight, particularly from the fourth week on. Problems occurred more in males than in females and in Cobb birds than in the Ross strain. Economic loss due to locomotion problems was higher for the Cobb strain.