Michael O. Ozoje

Morphological and microsatellite DNA diversity of Nigerian indigenous sheep

BackgroundSheep is important in the socio-economic lives of people around the world. It is estimated that more than half of our once common livestock breeds are now endangered. Since genetic characterization of Nigerian sheep is still lacking, we analyzed ten morphological traits on 402 animals and 15 microsatellite DNA markers in 384 animals of the 4 Nigerian sheep breeds to better understand genetic diversity for breeding management and germplasm conservation.ResultsMorphological traits of Uda and Balami were significantly (P < 0.05) higher than Yankasa, which were both higher than West African Dwarf (WAD) sheep. Stepwise discriminant analysis showed tail length, rump height, chest girth, ear length and chest depth as the most discriminating variables for classification. Mahalanobis distances show the least differentiation between Uda and Balami and the largest between WAD and Balami sheep. While 93.3% of WAD sheep were correctly assigned to their source genetic group, 63.9% of Yankasa, 61.2% of Balami and 45.2% of Uda were classified correctly by nearest neighbour discriminant analysis. The overall high Polymorphism Information Content (PIC) of all microsatellite markers ranged from 0.751 to 0.927 supporting their use in genetic characterization. Expected heterozygosity was high for all loci (0.783 to 0.93). Mean heterozygote deficiency across all populations (0.171 to 0.534) possibly indicate significant inbreeding (P < 0.05). Mean values for FST, FIT and FIS statistics across all loci were 0.088, 0.394 and 0.336 respectively. Yankasa and Balami are the most closely related breeds (DA = 0.184) while WAD and Balami are the farthest apart breeds (DA = 0.665), which is coincident with distance based on morphological analysis and population structure assessed by STRUCTURE.ConclusionsThese results suggest that within-breed genetic variation in Nigerian sheep is higher than between-breeds and may be a valuable tool for genetic improvement and conservation. The higher genetic variability in Yankasa suggests the presence of unique ancestral alleles reflecting the presence of certain functional genes which may result in better adaptability in more agro-ecological zones of Nigeria. These genetic characteristics are potentially useful in planning improvement and conservation strategies in Nigerian indigenous sheep.

A preliminary screening of genetic lineage of nigerian local chickens based on blood protein polymorphisms

Fueron tomadas muestras de sangre para el analisis proteico en tres variedades de gallinas autoctonas nigerianas (de plumaje normal, de plumaje rizado y de cuello desnudo) y una variedad exotica (Anak Titan). Cada una de estas poblaciones representa un genotipo. Se usaron muestras de sangre de 50 animales por genotipo para valorar la diversidad genetica de las gallinas autoctonas nigerianas. Fueron observados un total de 18 grupos a partir de las cuatro variedades durante la resolucion de la proteina utilizando electroforesis en gel de poliacrilamida con dodecilsulfato sodico (pagina de SDS). El dendograma desarrollado desde los diferentes grupos observados revelo que las variedades se encontraban claramente separadas unas de otras y con una semejanza genetica media entre las cuatro variedades del 55 percent, siendo la variedad de cuello desnudo las mas separada.

Genetic diversity analysis of the mitochondrial D-loop of Nigerian indigenous sheep

Los recursos ganaderos autoctonos son de caracter estrategico en los aspectos socioeconomicos de los sistemas agricolas para garantizar la seguridad alimentaria en los paises de escasos recursos. Por lo tanto, conocer mejor la importancia de la variabilidad genetica es vital para su futura utilizacion, por medio de la conservacion. Se presenta el primer analisis de la diversidad genetica en ovejas de Nigeria basado en la region de control (D-loop) del Ovis aries del genoma mitocondrial, utilizando 1.179 bases entre las posiciones 15.437 y 16.616 de pares de bases. Una muestra de 290 animales, compuesta por las razas Balami, West African Dwarf (WAD), Uda y Yankasa, fue tomada al azar de toda Nigeria. Se observaron noventa y seis (96) haplotipos, con una alta diversidad media en cuanto a estos de 0,899 ± 0,148. La diversidad genetica fue mayor en la raza Uda (0,921 ± 0,021) y menor en la raza WAD (0,852 ± 0,061). Los indices de poblacion especificos FST variaron de 0.00133 en la raza Uda a 0,00335 en la razaWAD. La raza Yankasa presento el mayor numero de posiciones polimorficas (201), mientras que el menor lo mostro la raza Uda (96). Analisis de la varianza molecular revelo que 0,23% de la variacion se encuentra entre las poblaciones, en comparacion con el 99,77% de variacion que se encuentra dentro de las poblaciones. El arbol filogenetico indica que los linajes mitocondriales de las razas ovinas partieron de un origen comun en conformidad con la primera divergencia de la raza Yankasa, seguida por WAD, mientras que las razas Balami y Uda se encuentran mas estrechamente relacionadas. Estos resultados demuestran que la divergencia evolutiva de las poblaciones ovinas de Nigeria, basados en el ADN mitocondrial de la region control, puede coincidir con la distribucion geografica en Nigeria e indican una tasa importante de cruzamiento entre ellas. Esto podria tener ventajas desde el punto de vista de la gestion de la mejora y las estrategias de conservacion y preservacion a largo plazo de las ovejas autoctonas de Nigeria.

Multifactorial discriminant analysis of morphological and heat-tolerant traits in indigenous, exotic and cross-bred turkeys in Nigeria.

Este estudio examina la capacidad para distinguir los rasgos morfologicos y de tolerancia al calor en pavos autoctonos, exoticos y cruzados en Nigeria mediante el analisis discriminante multivariado. Un total de 228 pavos de 20 semanas de edad fueron utilizados en el estudio. Los parametros corporales medidos fueron el peso corporal (BW), diametro longitudinal (BL), longitud del tarso (SL), longitud del muslo (TL), longitud de quilla (KL), perimetro toracico (BG), temperatura rectal (RT), frecuencia del pulso (PR), frecuencia respiratoria (FR) y el indice de estres termico (HI). El analisis de la varianza revelo que los pavos exoticos mostraban valores significativamente ( p < 0,05) mayores que los pavos autoctonos de Nigeria y que los cruzados para todos los rasgos morfologicos, con la excepcion de la TL. Sin embargo, los pavos autoctonos y los cruzados parecian tener mas capacidad de adaptacion que los exoticos en base a valores de HI mas bajos. El dimorfismo sexual se observo solo en los caracteres morfologicos, donde los machos presentaron de forma significativa ( p < 0,05) un mayor BW, BL, SL, TL y KL que en las hembras. Sin embargo, el analisis discriminante por pasos revelo que BW, TL y HI, fueron las variables mas discriminantes a la hora de separar los tres grupos geneticos. La mayor distancia de Mahalanobis se observo entre los pavos autoctonos y exoticos (36,68), mientras que la distancia mas corta se registro entre los pavos autoctonos y los cruzados (7,97). El diagrama canonico puso de manifiesto la heterogeneidad de las poblaciones de pavo, agrupando las aves por separado. En el nivel de asignacion mas cercano del analisis discriminante, el 100,00%, el 98,73%y el 96,43%de pavos exoticos, cruzados y autoctonos fueron asignados correctamente en sus grupos de origen genetico. Los presentes hallazgos podrian ayudar a la implementacion de una estrategia de conservacion y mejora de los pavos autoctonos hacia el desarrollo sostenible de los recursos zoogeneticos.

Physiological adaptation of local, exotic and crossbred turkeys to the hot and humid tropical environment of Nigeria

Abstract A total of 300 birds consisting of 120 local, 120 crossbred and 60 exotic turkeys were used to compare physiological adaptation of birds raised under the high-heat stress environment of Nigerian tropical humid climate. Genotype significantly (P<0.05) affected heat tolerance traits with the highest mean values for rectal temperature, pulse-rate and heat stress index observed in exotic turkeys. Genotype also had significant (P<0.05) effect on serum biochemical parameters such as glucose (GLU), potassium (K+) and Chloride (Cl–). The haematological indices of the birds such as haemoglobin, white blood cell count and heterophyl/lymphocyte ratio (H/L) were equally affected by the different genetic groups (P < 0.05). The significantly higher (P<0.05) H/L ratio of the exotic turkeys was an indication of heat stress. The better performance exhibited by local and crossbred turkeys could be exploited in management, conservation and selection decisions of animal genetic resources under tropical conditions.

Interrelationship studies between heat stress traits, blood andserum biochemical indices of extensively managed Nigerian Sheep

The exposure of sheep to elevated ambient temperatures induces an increase in the dissipation of excess body heat, in order to overcome this excessive environmental heat load. Dissipation of excess body heat is emitted by evaporation of water from the respiratory tract and skin surface via panting and sweating.The following heat stress traits were measured; body temperature, rectal temperature, pulse rate and respiratory rate after the sunrise and before the sunset. While blood and serum biochemical indices measured were blood glucose, total serum protein, globulin, cholesterol and triglycerides. No significant relationship(P>0.05) was recorded between heat stress traits and blood biochemical indices studied. However, we observed a positively significant (P<0.01) relationship betweenblood and serum biochemical indices studied. Similarly, a positively significant (P<0.01) relationship was observed between heat stress traits examined.

Analysis of the body structure of Djallonke sheep using a multideterminant approach

This study aimed at using a multivariate approach to describe the body structure of Djallonke sheep in northern Ghana and to determine which approach explains better the variation in body composition. Live weight (LW) and linear body measurements including heart girth (HG), neck girth (NG), chest depth (CD), height at withers (HW), rump height (RH), body length (BL) and pin-bone width (PBW) were obtained from 172 sheep aged between two and three years. The fixed effects of sex and age were tested using the general linear model (GLM) while the Nearest Neighbor method of Hierarchical Cluster Analysis was used to group body traits into clusters. Principal Component Factor Analysis was used to describe the variation in body traits where extracted factors were varimax rotated to enhance interpretability. The analysis of variance revealed significant (P 0.05). Age had no significant influence (P> 0.05) on the body traits. The sheep weighed 26.92 ± 0.89 kg averagely and had averages of other body measurements to be: 71.74 ± 1.23, 40.52 ± 0.79, 27.73 ± 0.52, 60.72 ± 0.86, 59.61 ± 0.87, 58.87 ± 1.06 and 12.81 ± 0.23 cm for HG, NG, CD, HW, RH, BL and PBW, respectively. The product moments of correlation were positive and significant (P< 0.05, 0.01;r= 0.18–0.99) for all pairs of traits. The body traits were categorized mainly into two clusters with the first cluster comprising the HG, HW, RH and BL while NG, CD and PBW formed the second cluster. The grouping of the traits was slightly different in Factor analysis where two underlying principal components (PC) were extracted to discern the variance structure of the Djallonke sheep. The first principal component which consisted of CD, HW, RH, BL and PBW explained 61.26 percent and the second, 12.92 percent thereby giving a maximum of 74.17 percent generalized variance in body measurements. The traits loaded on the first principal component are closely associated with bone growth hence describing the general body size conformation while the traits (HG and NG) on the second component seem to describe only the thoracic region. It can be concluded that both the Hierarchical Cluster analysis and the Factor analysis grouped body traits similarly but the later is to be recommended because of the additional ability of indicating the amount of variation explained by the developed factors

Variation in Growth and Linear Body Measurements of Rabbits Due to Generation Differences, Housing Systems, Sex and Season

The aim of the study is to determine the effect of generational differences, housing systems, sex and seasonal variations and their interactions on the growth and linear body parameters of rabbits. A total of ninety-six (96) weaner rabbits (Chinchilla and New Zealand White crossbred) were used for this study and were divided into forty-eight (48) per generation. These forty-eight weaner rabbits were further divided into four males in three replicates (12) as well as four females in three replicates (12) for cage (24) and also repeated in deep litter system (24). This experiment was carried out in four seasons with seasonal divisions being made according to the climatic conditions prevalent in southwest Nigeria namely early dry season (EDS) from September to November, late dry season (LDS) from December to February, early rainy season (ERS) from March to May and late rainy season (LRS) from June to August. This experiment was carried out for two generations and data obtained were analysed using Analysis of Variance in a 2 x 2 x 2 x 4 factorial arrangement. The study showed that most of the body linear measurements investigated increased significantly in the first than the second generation and during the

Preliminary association of coat colour types and tolerance to Haemonchus contortus infection in West African Dwarf sheep

Reduction in livestock productivity from internal parasites remains a major problem including the roundworm Haemonchus contortus. Treatment is rather expensive in most resource poor regions of the world, and the use of genetically resistant genotypes have been advocated. Our preliminary study investigated the association of coat colour types and tolerance to H. contortus infection in West African Dwarf (WAD) sheep. Twenty-four WAD sheep (12 males and 12 females) representing five coat colour types were orally dosed with 1000 H. contortus third-stage infective larvae, and data were collected over a 3-week period on initial and post-infection body weight (IBW and PIBW), packed cell volume (PCV), total serum proteins (TSP), albumin (ALB), globulin (GLB) and faecal egg counts (FEC). Coat colour was significantly associated with tolerance to H. contortus infection (p<0.05). Brown mouflon (AmabbSs) sheep showed the highest mean PIBW, PCV and GLB (15.16±1.76 kg, 30.67±3.53% and 31.17±0.54 g/dl), respectively, while brown sheep with extensive white markings (aabbss) had the highest mean TSP and ALB value (73.40±2.02 g/dl and 44.47±0.49 g/dl), respectively. Badger face (AbfaB-S-) sheep had the least mean values of PIBW, PCV, TSP, ALB, GLB and the highest FEC. There were no significant associations with sex and its interactions with coat colour on post-infection performances of WAD sheep in this study. Our results suggest that brown sheep can tolerate H. contortus infection better than other coat colour types, which may be due to the linkage between coat colour and resistance loci, linkage disequilibrium effects or resulting from pleiotropic effects deserving further study.

Mitochondrial DNA hypervariable region 1 diversity in Nigerian goats – CORRIGENDUM

Moses Okpeku, Sunday O. Peters, Ikhide G. Imumorin, Kyle C. Caires, Varun K. Sharma, Mathew Wheto, Rakesh Tamang, Adeyemi S. Adenaike, Michael O. Ozoje and Kumarasamy Thangaraj doi: 10.1017/S2078633616000102, Published by Cambridge University Press, 3 January 2017 In the above publication (Okpeku, 2017) the incorrect affiliation was given for Kyle Caires. The correct affiliation is: Department of Human Nutrition, Food and Animal Sciences, College of Tropical Agriculture and Human Resources, University of Hawaì i at M anoa, Honolulu, HI 96822, USA