Search

The interferon regulatory factor gene family encodes transcription factors with multiple biological functions, which include reproduction, cell differentiation and immunity. Interferon regulatory factor-5 (IRF-5) gene is involved in immune defence against virus, stress response, activation of type I interferon genes, cell differentiation and growth. This experiment was conducted to identify and characterise single nucleotide polymorphisms in exons 3, 4, 5 and 7 of IRF-5 gene in Nigerian local chickens. Exons 3, 4, 5 and 7 of IRF-5 gene were amplified and sequenced. Single nucleotide polymorphisms (SNPs) present in exons 3, 4, 5 and 7 of IRF-5 gene were identified and analysed using Clustal W, DnaSp and SNAP2 software packages. Four SNPs, rs317511101, rs312902332, rs315149141 and rs739389464, were identified in exon 3 of IRF-5 gene in all the three genotypes. Exon 4 of the gene was conserved while three of the SNPs (rs736423928, 170C>T and rs740736761) identified in exon 7 were shared among the three genotypes. Linkage disequilibrium of 1.00 existed between rs317511101 and rs315149141 polymorphisms identified in exon 3 of normal feathered and frizzle feathered chickens. Mutation rs740736761 identified in exon 7 had the highest polymorphism information content obtainable for any biallelic marker. Most of the SNPs identified in exons 3, 5 and 7 were synonymous and singletons which could not be used for association study. The study concluded that only haplotypes in exons 3 and 7 of IRF-5 gene can be used in marker-assisted selection when improving Nigerian local chickens.

Newcastle disease and heat stress reduce the productivity of local chickens of Nigeria (LCN). This study compared the antibody response to Newcastle disease and heat tolerance among different LCN genotypes in hot humid tropics using multivariate discriminant analysis. A total of 299 birds were used for the study. Geometric mean titre against Newcastle disease before vaccination (GMTB), geometric mean titre against Newcastle disease after vaccination (GMTA), rectal temperature at week 4 (RT4), pulse rate at week 4 (PR4), respiratory rate at week 4 (RR4), heat stress index at week 4 (H4), rectal temperature at week 13 (RT13), pulse rate at week 13 (PR13), respiratory rate at week 13 (RR13) and heat stress index at week 13 (H13) were measured. All the traits were significantly (p 0.05) affected by the genotype while sex differences were only observed in GMTB, GMTA and RR13. The stepwise discriminant analysis revealed RR4, PR13, RT13, H4, GMTA, GMTB, H13 and RT4 to be effective in differentiating the three chicken genotypes. Two canonical variables that accounted for 60.21% and 39.79% of the total variation were revealed. Linear discriminant functions for differentiation of the three chicken genotypes were also developed. 87.39% of normal feather, 76.58% of naked neck and 100% of frizzle feather chickens were correctly assigned into their genotypes. The longest Mahalanobis distance was observed between normal feather and frizzle feather chickens. The discriminant functions developed in this study could be used to differentiate the three genotypes of LCN using antibody response to Newcastle disease and heat tolerance.

Feed and alarm calls induce arousal in chicks, the former for feeding and the latter for danger. However, the response of birds genetically selected for meat or egg production to these calls have not been investigated. Thirty-six chicks each of the ISA Brown pullet and FUNAAB Alpha broiler (2 weeks old) were randomly allocated into three groups per strain and subjected to three playbacks: no call (NCP), feed call (FCP) and alarm call (ACP) continuously for 1 h. The test was carried out for 3 days/week for two weeks. The behaviours monitored were foraging, feeding, pecking (grouped as oral-related behaviour, ORB), freezing and clustering (grouped as fear-related behaviour, FRB). The eye (ET) and under wing (WT) temperatures were measured before and after each call and the change (ΔET and ΔWT) calculated. Tonic immobility (TI) test was performed after each call and the number of attempts to induce TI (NOATI) and the duration of TI (DTI) was recorded. Data on these two behavioural categories were subjected to General Linear Model analyses separately for each call having strain and day as fixed factors. The ΔET, ΔWT, NOATI and DTI were analyzed using Mann-Whitney U test. On both days, ΔET and ΔWT was similar after exposure to 1 h of FCP, ACP and NCP. FCP caused more (P 0.05) by day and strain. Strain × day interaction influenced (P 0.05) strain × day or strain effects on ORB and FRB, with ORB greater (P

The aim of this study was to determine breed differences in the behavioural responses of two domestic chicks to feed and alarm playback calls. Thirty two (32) each of Nigerian indigenous chicks (NIC) and commercial broiler chicks (CBC) of the same age group (a day old) were divided into four replicates with eight chicks per replicate. On day 1, chicks were acclimatized to the test arena for 30 min. On days 2 and 4, the feed call playback was played for one minute and was repeated every 10 min in a 50 min test period (playback repeated four times). On days 3 and 5, the alarm call playback was played for one minute and was repeated every 10 min in a 50 min test period. The behaviour of the chicks was recorded continuously for 50 min using digital cameras. The feed call behavioural responses monitored included the percentage of birds feeding, pecking and foraging while the alarm call behavioural responses recorded were the percentage of birds running, freezing, clustering and crouching. In addition, the duration was recorded for clustering and crouching behaviours. Data on the behaviour of the chicks prior to the playback, during the 1 min playback (immediate response) and after the playback (recovery period) was analysed using both the independent T and Mann-Whitney U tests. Prior to the playback, there was no breed difference on feeding and pecking but a higher percentage of NIC were foraging than the CBC. There was no significant (P > 0.05) effect of breed on the immediate response of the chicks to the feed call in terms of the percentage of chicks feeding, pecking and foraging. The immediate response to the alarm call playback showed that the percentage of CBC and NIC that ran, froze and clustered were similar (P > 0.05). However, the percentage of CBC that crouched was greater (P