Vitamin A dietary supplementation reduces the mortality of velogenic Newcastle disease significantly in cockerels

Abstract

This project was undertaken to find ways of reducing mortalities and economic losses due to velogenic Newcastle disease (VND) in areas where the disease is enzootic. Four groups of cockerels of 44 birds each were used for this experiment. The birds in groups 1 and 2 received no dietary vitamin A supplementation, whereas groups 3 and 4 received 300 iu and 600 iu of vitamin A per kilogram of commercial feed, respectively, from 1 week of age till the end of the experiment. At 6 weeks of age, the birds in groups 2, 3 and 4 were inoculated intraocularly with a VND virus (duck/Nigeria/Plateau/Kuru/113/1991). The birds in Group 1 were given phosphate-buffered saline intraocularly. Clinical signs appeared in Group 2 birds on day 3 PI and in groups 3 and 4 on day 5 PI. The clinical signs included a drop in feed and water consumption, depression, diarrhoea, torticollis and paralysis in all the infected groups. The average body weights of all groups were significantly different from one another on day 14 PI with Group 2 birds having the lowest body weight. Mortalities were highest in Group 2 birds (0%, 93.18%, 72.73% and 56.82% in groups 1, 2, 3 and 4 respectively). The antibody response in all the groups was significantly different from one another on days 14 and 21 PI. Group 2 birds had the lowest titres on those 2 days and showed more severe atrophy of the bursa, spleen, thymus and fibrin deposition in the spleen and thymus than the birds in groups 3 and 4. The above observations show that vitamin A dietary supplementation delayed the onset of clinical signs and significantly reduced body weight loss, atrophy of the bursa, spleen and thymus, and mortalities by 36%. It also significantly potentiated haemagglutination inhibition antibody response.

Comparison of blood biochemistry responses of cockerels and turkeys experimentally infected with a velogenic newcastle disease virus

“…The clinical signs in the challenged turkeys in this experiment were mainly depression, diarrhoea and nervous signs. The lesions in the major lymphoid organs in this experiment had been described in unvaccinated infected cockerels and turkeys (Piacenti et al, 2006;Wakamatsu et al, 2006;Ezema et al, 2009;Okoye et al, 2010;Okpe et al, 2015;Okorie-Kanu et al, 2016 b) No proventricular haemorrhage, intestinal and caecal tonsil ulcers were observed in turkeys. This is in agreement with reports of Hanson and Spalatin (1973), Piacenti et al (2006) and Wakamatsu et al (2008) in commercial turkeys, Igwe et al (2014) in guinea fowls and Okorie-Kanu et al (2016a) in ducks.…”

Low dose velogenic viscerotropic Newcastle disease virus infection caused 30% mortalities in Anak broilers but none in Lohmann Brown layer chickens

“…This obviously led to serious loss of some viral particles and the production of abnormally low mortalities of 0 and 30% in the layer chickens and broilers respectively. In our earlier experiments using this same virus at median embryo effective of 10 6.1 to 10 8.46 after 2-3 days storage at −40°C, we had mortalities of 76-100% in chickens and 60% in turkeys (Igwe et al 2014;Okpe et al 2015;Ezema et al 2016;Okoroafor et al 2017). Wakamatsu et al (2006) studied different strains of vvND virus infection in 4 and 6 weeks old chickens and reported 100% and 92% mortalities respectively.…”

Pathogenesis of Velogenic Genotype VII.1.1 Newcastle Disease Virus Isolated from Chicken in Egypt via Different Inoculation Routes: Molecular, Histopathological, and Immunohistochemical Study

“…The observed nephritis features were congestion, tubulo-interstitial nephritis, and glomerulitis. All challenged groups showed diffuse necrotic nephritis which involved the renal tubules [ 51 , 72 , 73 , 74 ], while the choanal group showed focal renal necrotic lesions, suggesting a wider systemic distribution of NDV through other routes of inoculation [ 62 ]. In terms of the lymphoid organs (bursa of Fabricius, spleen, thymus, and cecal tonsils), several lesions were noticed in all inoculated groups, including lymphocytic depletion and necrosis, in agreement with several previous reports [ 55 , 61 , 74 , 75 ].…”