Nigerian Goat Breeds Research Articles

Evaluation of resistance to gastrointestinal helminth nematodes in two naturally infected indigenous Nigerian goat breeds.

Tropical goat breeds often have at least modest resistance to gastrointestinal nematode parasites (GIN), but enhancement of GIN resistance is important for breed improvement. This study compared changes in fecal egg count (FEC), packed cell volume, and body weight in Red Sokoto (RS) and Sahelian (SH) male and female weaner kids and adult goats. The RS is found throughout Nigeria, but the SH is found only in the arid Sahel. Goats were evaluated fortnightly for 20 times (MT) under normal grazing conditions and natural GIN infection over 9.5months, beginning in the dry season (November) and ending at the end of the subsequent wet season (August). Animals were dewormed at the start of the study and during the rainy season (MT 18). Breed differences in FEC and PCV were not observed in weaners. Weaner females had lower FEC than males but were rapidly re-infected after deworming, perhaps in association with attainment of puberty. Adult SH goats of both sexes had lower FEC than RS goats in MT 8 through 17, suggesting a stronger acquired immune response. The FEC in lactating females of both breeds increased rapidly after deworming, to ≥ 3000 eggs per gram of feces at MT 19 and 20. The optimal time to evaluate GIN resistance in weaners was during the early rainy season, but the decision to focus on the initial high FEC near MT 15 or wait until mobilization of the acquired immune response near MT 17 requires further consideration.

Genetic polymorphism in the POU1F1 gene in Kalahari Red and two Nigerian goat breeds and their relationship with litter size

POU1F1 gene controls cell differentiation and animal growth by binding to target DNA promoter sequence, thereby auto-regulating its own expression and expression of growth hormone (GH), prolactin (PRL) and thyroid-stimulating hormone beta sub-unit (TSHβ) genes. Therefore, the exploration of caprine POU1F1 gene polymorphisms may be vital in the formulation of conservation and breed improvement strategies. In this study, POU1F1 gene was characterized for sequence polymorphisms in 366 individuals from two Nigerian goat breeds ((West African Dwarf (WAD) and Red Sokoto (RS)) and one South African goat breed (Kalahari (KR)). The effects of polymorphisms on litter size were investigated using linear mixed model. Two intronic mutations (g.306G>A and g.11236C>T) were identified. However, no significant association was found between the Single Nucleotide Polymorphisms (SNPs) and litter size in the three populations. The genetic distance based on POU1F1 investigated region revealed that the two Nigerian breeds and the South African breed were identical (pairwise genetic distance of 0.00). Phylogenetic tree constructed from the pairwise distance clustered the three breeds into a single clade with the two Nigerian goat breeds having a more recent common ancestor. Structural analysis of the POU1F1 protein confirmed that Pit-Oct-Unc transcription factors domain (POU) and Homeodomain (HOX) domains are conserved in mammals, with several overlapping sub-domains across the same region in all the three populations. We found a subdomain Subfamily of SANT domain or myb/SANT-like domain in Adf-1 (MADF) in goat, cattle, buffalo and camel that has not been reported in mammals

Morphological characterization and evaluation of heat tolerance traits in Nigerian goat breeds

There are three main breeds of goat in Nigeria: The West African Dwarf (WAD), the Red Sokoto and the Sahel. Goats are renowned for their hardiness and can survive in most environments. The goats sampling was carried out from farms and markets across different states in Nigeria, according to the geographical distribution of the breeds published by Blench (1999). This experiment was carried out to analyse morphological variability among Nigerian goats. A total of 318 goats spread across the three Nigerian breeds were used in the following populations (57 Sahel, 187 Red Sokoto and 137 West African Dwarf). Data were collected on body weight, linear body measurements and heat tolerance traits and were subjected to analysis of variance using the fixed effects of breed, sex and location. Results showed that breed, sex and location significantly (P<0.05) affected all the linear body measurements and heat tolerance traits. The Sahel breed had the highest values in most of the measured traits compared to the West African Dwarf and the Red Sokoto breeds of goat. It was observed that goats from the northern part of Nigeria were heavier than their southern counterparts, and this can be likened to their genetic makeup and the extent of its interaction with the environment. The results of the study confirmed the population structure of Nigerian goat breeds and showed that they possess enough diversity to enhance genetic improvement for higher survival and productivity.

Cytologgy screening of Nigerian ecotype goats for reproductive potentialities

X-chromatin (drumstick) screening evaluated through the identification of the drumstick appendages of neutrophilis was carried on Nigerian goat breeds. 150 weaner bucks and 150 weaner does were used for the study. Some of the animals exhibited aberrant x-chromatin while some showed normal percentage of incidence of the drumstick. Both genotype and sex differences had significant effect (P>0.05) on the x-chromatin in genotype III (RSG * WAD), Genotype III design should not be used for reproductive purpose except on the ground of fattening for slaughter

Sequencing, polymorphism and phylogenetic characterisation of KiSS-1 gene in two Nigerian indigenous goat breeds

KiSS-1 gene encodes a protein product kisspeptin which are intense inducers of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secretion in various mammalian species through its receptor GPR54 (G protein-coupled receptor-54). A total of 100 goat compromising of Red Sokoto (n = 72) and Sahel (n = 28) breeds were used to detect single nucleotide polymorphisms (SNPs) in the intronic region of the KiSS-1 gene by sequencing and investigate their relationship with other goat breeds. Nucleotide sequence analysis revealed five novel SNPs (g.1745G>A present in Red Sokoto, g.1776G>A, g.1827A>G, g.1857T>C and g.2208T>C present in Red Sokoto and Sahel breeds). To obtain a correct phylogenetic relationship between goat breeds, nucleotide sequences were compared to other sequences in NCBI database using a BLASTn algorithm and retrieved for further analysis. Neighbour-joining phylogenetic relationship tree constructed revealed two distinct clusters with ancestral lineage of 100% identity. Nigerian goat breeds (Red Sokoto and Sahel) clustered into a clade with Indian goat breeds (Ganjam and Osmanabadi) while the second cluster involved eight other goat breeds. Genetic distance estimate revealed high genetic similarity between Red Sokoto and Sahel breeds as observed in their genetic distance value of 0.003. The nucleotide sequences of the two Nigerian goat breeds (Red Sokoto and Sahel) for KiSS-1 gene were submitted to GenBank database and have accession numbers: MN122316 and MN122317, respectively. The analysis of polymorphism in KiSS-1 gene indicates that genetic variation exists in the goat breeds studied. Therefore, attempts can be made to investigate the association of these polymorphism with reproductive traits in Nigerian goat breeds.

Phenotypic resistance of indigenous goat breeds to infection with Haemonchus contortus in northwestern Nigeria.

Two studies at the National Animal Production Research Institute (NAPRI), Zaria, Nigeria, compared Red Sokoto (RS), Sahelian (SG), and West African Dwarf (WAD) goats after experimental or natural infection with Haemonchus contortus. In the first study, 20 RS, 17 SG, and 14 WAD kids were challenged at 6months of age with 5000 L3 larvae of H. contortus. Fecal egg counts (FEC), packed cell volumes (PCV), and body weights (BW) were recorded 0, 28, 35, and 42days after infection. The FEC and PCV were affected only by time of measurement. In the second study, 322 RS and 97 SG kids were produced at NAPRI over 3years, weaned at 4 to 6months of age, dewormed, returned to contaminated pastures, and evaluated 28 and 35days later. Effects of breed, year, breed × time interaction, and breed × year interaction were observed for PCV and BW; FEC was only affected by time of measurement, year and breed × year interaction. The FEC were larger and PCV were smaller on day 35 compared to day 28 and in year 2 compared to years 1 and 3. The SG kids were notably smaller than RS kids in year 2, with higher FEC and lower PCV, but FEC were larger for RS kids in years 1 and 3. Differences in parasite resistance among these Nigerian goat breeds were therefore small and likely reflected underlying differences in growth, development, and disease history.

Genetic polymorphism of β-Lactoglobulin gene in indigenous Nigerian goat breeds

Polymorphism at the ?-Lactoglobulin (?-LG) gene of three Nigerian goat breeds, namely: the West African Dwarf, Sahel and Red Sokoto goats, was investigated using the Polymerase Chain Reaction-Random Fragment Length Polymorphism (PCR-RFLP) method. The restriction endonucleases used in the study were Rsal and Mspl, respectively. The results revealed the existence of only one polymorphic variant (allele A) with a gene frequency of 1.0 in all the three goat breeds studied. The amplified products were observed at 120 bp and the restriction digestion with Rsal revealed just one genotype at the ?-LG locus. It was concluded that there was the absence of polymorphism at the ?-LG locus of the goats investigated.

Physiological and haematological indices of two Nigerian goat breeds reared under uniform conditions during dry season

Introducing an indigenous or exotic breed to unfamiliar environment paves way for livestock improvement. This study examined the physiological and haematological indices of 24Red Sokoto (RS) and West African Dwarf (WAD) goats reared under uniform condition in Ilorin, to determine adaptability of RS goats over a period of 8 weeks. The goats were grouped based on gender and two age ranges (3 -5 months and 9 - 12 months). Rectal temperature (RT), heart rate (HR) and respiratory rate (RR) were monitored twice daily (morning: 7.00 – 8.00am; afternoon: 4.00 – 5.00pm) while blood samples for complete blood count were collected twice during the experiment. The result showed that the examined physiological parameters were within the normal threshold, and were more influenced ( P <0.05) by sex rather than breed or age. Breed influenced HR with RS exhibiting higher( P <0.05) value than WAD (Morning: 79.38 vs 76.28 beat/min; Afternoon: 92.88 vs 89.89 beat/min).Morning RT and HR were influenced ( P <0.05) by age (3 – 5 vs 9 – 12 months: RT - 39.21 vs 39.06 0 C; HR - 75.63 vs 80.89 beat/min). The female exhibited significantly ( P <0.05) higher HR and RR than male goat. Sex had significant ( P <0.05) interaction with breed and age for HR while the interaction between breed and age was significant ( P <0.05) for afternoon RT and HR. Haematological results showed inconspicuous variation between WAD and RS goat. It is therefore concluded that there was no adverse effect of unfamiliar environment on the physiology and hematology of RS goats when reared under semi-intensive system in Ilorin, Nigeria. Keywords: Adaptability, Breed, Haematology, Physiology, Sex

Mutations in inhibin alpha gene and their association with litter size in Kalahari Red and Nigerian goats

This study was conducted to identify SNPs in inhibin alpha (INHA) gene and investigate their association with litter size in two Nigerian goat breeds {West African Dwarf (WAD, n = 226), Red Sokoto (RS, n = 70)} and Kalahari Red (KR, n = 70). Sequence analyses revealed four SNPs {g.−65C > G/rs643347356 (5’UTR), g.2518G > A (a novel variant in exon 2), g.3041A > G/rs641311609 (exon 3) and g.3234C > T/rs670889338 (3’UTR)}. Homozygous wild type CC at g.−65C > G and GG at g.2518G > A loci were predominant genotypes in Kalahari Red goats. CC was the predominant genotype in all the three breeds at g.3234C > T locus and the frequency of allele C was 0.88, 0.98 and 0.98 in WAD, RS and KR populations respectively. Allele diversity index was low (He < 0.3) in the three breeds at g.−65C > G, g.2518G > A and g.3234C > T loci. WAD and KR goats had moderate genetic diversity (0.25 ≤ PIC ≤ 0.5) at g.3041A > G locus. Pair-wise comparison revealed that does having CT genotype at g.3234 C> T locus had significantly (P = 0.01) larger litter size compared with CC in WAD goats, while SNP genotype at other loci were not significantly associated with litter size.

Modelling functional and structural impact of non-synonymous single nucleotide polymorphisms of the DQA1 gene of three Nigerian goat breeds

The DQA1 gene is a member of the highly polymorphic MHC class II locus that is responsible for the differences among individuals in immune response to infectious agents. In this study, the authors performed a comprehensive computational analysis of the functional and structural impact of non-synonymous or amino acid-changing single nucleotide polymorphisms (SNPs) (nsSNPs) that are deleterious to the DQA1 protein in Nigerian goats. A 310-bp fragment of exon 2 of the DQA1 gene was amplified and sequenced in 27 unrelated animals that are representative of three major Nigerian goat breeds (nine each of West African Dwarf, Red Sokoto, and Sahel of both sexes) using genomic DNA. Forty-two nsSNPs were identified from the alignment of the deduced amino acid sequences. Based on the PANTHER, PROVEAN and PolyPhen-2 algorithms, there was consensus in identifying the mutants I26D, E114V and V115F as being deleterious. Further, differences between the native and the mutant proteins in the subsequent molecular trajectory analysis (stabilizing and flexible residue composition, total grid energy, solvation energy, coulombic energy, solvent accessibility, and protein-protein interaction properties) revealed E114V and V115F to be highly deleterious. Combined mutational analysis comparing the amutant (I26D, E114V and V115F mutations collectively) with the native protein also showed changes that could affect protein function and structure. Further wet-lab confirmatory analysis in a pathological association study involving a larger population of goats is required at the DQA1 locus. This would lay a sound foundation for breeding disease-resistant individuals in the future. ______________________________________________________________________________________ Keywords : Goats, in silico, mutants, protein, tropics

Is it possible to obtain zero estimates of genetic diversity? A case study of the Nigerian indigeneous goat breeds at the β-lactoglobulin gene locus

The current investigation was conducted to appraise the genetic diversity and genetic distance of three goat populations namely; Red Sokoto, Sahel and West African Dwarf (WAD), in Nigeria, making use of blood samples collected from 20, 20 and 20 individual from which blood DNAs were extraction, respectively. The DNAs extracted were used to study polymorphism at the ?-lactoglobulin gene locus using RLFP-PCR process. Results revealed that the mean total number of alleles was 1 while the effective number of alleles was also 1. The percentage of polymorphic locus was 0% while Shannon?s information index, observed homozygousity, expected heterozygosity, unbiased expected heterozygosity and inbreeding coefficient (F) were all observed to be 0.000. The pairwise Fst was 0.000 between all the breeds of goats. Variation within and between the populations of goats was 0% at p&gt;0.05. The genetic distance between the goat breeds was 0.000. The present study revealed that RLFP-PCR may not be a powerful tool for the study of the ?-lactoglobulin gene locus and hence other methodologies should be employed for a broader judgment on the genetic status of the goat population at the locus.

Nucleotide sequence variability analysis of Major Histocompatibility Complex Class II DQA1 gene in Nigerian goats

Major Histocompatibility Complex (MHC) molecules loaded with peptides derived from invading pathogens are recognised by the immune system to produce a highly effective and specific response against foreign pathogens. A 310-bp fragment of exon 2 of the MHC Class II DQA1 gene was amplified in 27 animals made up of three major Nigerian goat breeds [West African Dwarf (WAD), Red Sokoto (RS) and Sahel (SH)]. Twenty amino acid polymorphic sites were found in Nigerian goats. Comparison of predicted amino acid residues of DQA1 exon 2 alleles of Nigerian goats with similar alleles from other caprine species revealed considerable congruence in amino acid substitution pattern. A significant positive selection signature was detected at the DQA1 locus of Nigerian goats in that non-synonymous substitutions occurred at a faster rate compared to synonymous substitutions (dN:dS ratio = 1.28 ; Z-Statistics= 1.634; P&lt;0.05). The evolutionary tree constructed using UPGMA, revealed that the southern WAD goat appeared to be more related to the northern RS than SH goat at the DQA1 locus. It will be interesting therefore, for future studies to investigate the association of the genetic variants in DQA1 gene of Nigerian goats with resistance/susceptiblity to diseases in order to conserve these precious animal genetic resources.

Mitochondrial DNA hypervariable region 1 diversity in Nigerian goats

SummaryGoats make up the largest group of ruminant livestock in Nigeria and are strategic in bridging animal protein supply gap and improving the economy of rural households. The hypervariable region 1 (HVR1) of the caprine mitochondrial genome was investigated to better understand genetic diversity important for improving selection for animal breeding and conservation programs. We sequenced and analysed the mitochondrial DNA (mtDNA) HVR1 in 291 unrelated indigenous Nigerian goats (West African Dwarf (WAD), Red Sokoto (RSO) and Sahel (SAH)), randomly sampled from around the country, and compared them with the HVR1 sequences of 336 Indian goats and 12 other sequences in five different species in the genusCapra(C. falconeri, C. ibex nubiana, C. aegagrus, C. cylindricornisandC. sibirica). A total of 139 polymorphic sites from 291 individuals were captured in 204 haplotypes. Within and among population variations were 77.25 and 22.74 percent, respectively. Nigerian goats showed high genetic diversity (0.87) and high FST values, and separate from Indian goats and other wild species. Haplogroups in WAD separates it from RSO and SAH concomitant with a different demographic history. Clear genetic structure was found among Nigerian goat breeds with appreciable variation in mtDNA HVR1 region. This study grouped Nigerian goat breeds into two major groups suggesting two different demographic origins for Northern and Southern breeds. High genetic admixing denotes different maternal origins and in contrast to evidence from goats from Levant and Central Asia, where goats were originally domesticated.

Association of SNP variants of MHC Class II DRB gene with thermo-physiological traits in tropical goats.

Host defense in vertebrates depend on many secreted regulatory proteins such as major histocompatibility complex (MHC) class II which provide important regulatory and effector functions of T cells. Gene polymorphism in the second exon of Capra-DRB gene in three major Nigerian goat breeds [West African Dwarf (WAD), Red Sokoto (RS), and Sahel (SH)] was analyzed by restriction fragment length polymorphisms (RFLP). Four restriction enzymes, BsaHI, AluI, HaeIII, and SacII, were utilized. The association between the polymorphic sites and some heat tolerance traits were also investigated in a total of 70 WAD, 90 RS, and 50 SH goats. Fourteen different types of alleles identified in the Nigerian goats, four of which were found in the peptide coding region (A57G, Q89R, G104D, and T112I), indicate a high degree of polymorphism at the DRB locus in this species. An obvious excess (P < 0.01) of non-synonymous substitutions than synonymous (dN/dS) in this locus is a reflection of adaptive evolution and positive selection. The phylogenetic trees revealed largely species-wise clustering in DRB gene. BsaHI, AluI, HaeIII, and SacII genotype frequencies were in Hardy-Weinberg equilibrium (P > 0.05), except AluI in RS goats and HaeIII in WAD goats (P < 0.05). The expected heterozygosity (H), which is a measure of gene diversity in the goat populations, ranged from 0.16 to 0.50. Genotypes AA (BsaHI), GG, GC and CC (AluI) and GG, GA, AA (HaeIII) appeared better in terms of heat tolerance. The heat-tolerant ability of SH and RS goats to the hot and humid tropical environment of Nigeria seemed better than that of the WAD goats. Sex effect (P < 0.05) was mainly on pulse rate and heat stress index, while there were varying interaction effects on heat tolerance. Variation at the DRB locus may prove to be important in possible selection and breeding for genetic resistance to heat stress in the tropics.

Interleukin-2 ((IL-2) gene polymorphism and association with heat tolerance in Nigerian goats

Interleukin-2 (IL-2) serves as a potent immuno-modulator, and plays a unique role in both the activation and maintenance of immune responses and in lymphocyte development. Gene polymorphism in IL-2 gene in three major Nigerian goat breeds [West African Dwarf (WAD), Red Sokoto (RS) and Sahel (SH)] was analysed by restriction fragment length polymorphisms (RFLP). The restriction enzyme, DraI was utilized. The association between the polymorphic site and some heat tolerant traits were also investigated in a total of 157 animals comprising 59 WAD, 69 RS, and 29 SH goats of both sexes. The IL-2 sequence displayed a 98% nucleotide identity with the referenced Cahi-IL-2 AY603404.1 orthologous sequence in GenBank. The phylogenetic trees revealed largely species-wise clustering, while the RS and SH goats were closer compared to the WAD goats. DraI genotype frequencies were in Hardy-Weinberg Equilibrium (P<0.05). The expected heterozygosity (H), which is a measure of gene diversity in the goat populations, ranged from 0.26 to 0.28. The heterozygote (TA) had a comparative advantage over the homozygote (AA) in terms of rectal temperature (39.21±0.08 (TT) and 38.86±0.13 (TA); P<0.05). The SH goats also displayed greater resistance to thermal stress compared to the RS and WAD goats. There were varying sex and interaction effects on the thermal indices. The present findings may find application in the selection of superior animals for resistance to heat stress as well as provide insight to questions about evolution, ecology and conservation of Nigeria indigenous goats.

WITHDRAWN:Genetic diversity and effect of selection at the mitochondrial hypervariable region in major Nigerian indigenous goat breeds.

Mitochondrial DNA (mtDNA) hypervariable region 1 ( HV1) sequences of three Nigerian indigenous goat breeds; West African Dwarf (WAD), Red Sokoto (RS) and Sahel were used to investigate the genetic diversity and effect of selection between and among these populations. Deoxyribonucleic acid (DNA) of Nigerian indigenous chicken was extracted from blood samples collected and preserved on Fast Technology for Analysis (FTA) paper. The extracted DNA were amplified and sequenced with predefined mitochondria (mtDNA) primer sets for HV1. Eighty-seven (87) polymorphic sites were found in 115 sequences which were grouped into 92 haplotypes. The mean haplotypic and nucleotide diversity were found to be 0.996±0.002 and 0.092±0.04 respectively. Genetic variation within population and between populations accounted for 97.26% and 2.74% of the total maternal variation respectively, with FST value of 0.0274. The Tajima's (D) and Fu's (F) test of neutrality were significant (P<0.05) and negative with the mean value of -1.12 and -21.34 respectively which is an indication of population expansion. The result further revealed that the WAD and RS goats are closely related with less genetic distance value of 0.01, and high genetic distance value (0.02) was observed between RS and Sahel goats and WAD and Sahel goats. Selection analysis result shows that there is more positive selection site (6 sites) to negative site (5 sites) among the Nigerian goats, which signifies how diverse they are as well as how nature has being trying to confer genetic fitness to these breeds.

Genetic Differentiation among Nigerian Indigenous Goat Populations

A total of 200 goats and 25 microsatellite markers proposed by the Food and Agricultural Organization and the International Society for Animal Genetics (FAO-ISAG) were used to determine the genetic diversity of three breeds of the Nigerian indigenous goats, namely Sahel (60), Red Sokoto (60), West African Dwarf (60) and one strain; Kano Brown (20). Genetic differentiation between the breeds and strain ranged from 0.011 to 0.037, and the least genetically differentiated populations were Kano Brown and Red Sokoto. Molecular variations were observed to be higher within populations (96%) than among populations (4%), which suggest higher heterozygosity within populations. This study showed that the Nigerian goats are admixed due to extensive cross-breeding and high gene flow amongst the breeds, and that the goats are geographically distributed in two major locations. Measures to conserve the uniqueness/distinctiveness of the Nigerian goat breeds should be sought, and gene flow between populations should be controlled by adopting effective breeding and management practices.

Diversidad genética y estructura de población de cabras autóctonas nigerianas usando marcadores microsatélites DNA

Se analizaron 29 microsatélites para evaluar la diversidad genética de tres razas caprinas Nigerianas y establecer las relaciones genéticas entre ellas utilizando las razas Saanen y Kalahari como poblaciones outgroup. Se analizaron 244 distribuidas de la siguiente manera: en Sahel (47), Maradi (47) y WestAfrican Dwarf (67), Kalahari (47) y Saanen (36). El ADN se extrajo a partir de sangre conservada en tarjetas FTA Classic siguiendo las instrucciones del fabricante y se amplificaron los microsatélites mediante PCR. Se calcularon el número medio de alelos (MNA), las heterocigocidades observada (Ho) y esperada (He) y las distancias genéticas entre pares de poblaciones. Se hizo una prueba de equilibrio Hardy-Weinberg (HWE) y un análisis de la estructura genética de las poblaciones mediante el programa STRUCTURE. La diversidad genética encontrada fue alta con valores de MNA entre 6,69 y 8,79 para Kalahari y West African Dwarf, respectivamente. Los valores de Ho oscilaron entre un 59 % para West African Dwarf y un 64,9 % para Saanen. La He más alta se encontró en la raza West African Dwarf (70 %), mientras que el valor más bajo se observó en la raza Saanen (He= 66,5 %). Los valores medios de Fis para las poblaciones estudiadas variaron entre 0,055 en Kalahari y 0,148 en West African Dwarf. La distancia genética más elevada fué la encontrada entre Saanen y Maradi (0,386) y la menor entre Maradi y Sahel (0,025). La prueba de equilibrio de HWE reveló que dieciocho, diecisiete, trece, veintitrés y veintiún loci estaban en equilibrio HWE (p&gt;0,05) en las razas Maradi, West African Dwarf, Sahel, Saanen y Kalahari, respectivamente. Una representación gráfica del análisis de estructura genética reveló que las cabras de Nigeria descienden de un ancestro común diferente de las razas sudafricanas y europeas que fueron utilizadas como grupos externos.

Mitochondrial DNA Sequence Analyses and Phylogenetic Relationships Among Two Nigerian Goat Breeds and the South African Kalahari Red

The first hypervariable (HV1) region of mitochondrial DNA (mtDNA) of two popular Nigerian goat breeds: West African Dwarf (WAD) (n = 35) and Red Sokoto (RS) (n = 37) and one exotic breed: Kalahari Red (KR) (n = 38) imported from South Africa were sequenced to investigate sequence diversity, genetic structure, origin, and demographic history of the populations. A total of 68 polymorphic sites were found in 110 sequences that grouped into 68 haplotypes. Average haplotype and nucleotide diversities for all breeds were 0.982 ± 0.005 and 0.02350 ± 0.00213, respectively. Phylogenetic analysis revealed two mtDNA lineages (A and B). Lineage A was predominant and included all haplotypes from WAD and RS and 5 out of 11 haplotypes of KR goats. The remaining haplotypes (6) of KR belong to lineage B. The analysis of molecular variance revealed a high-within breed genetic variance of 82.4% and a low-between breed genetic variance of 17.6%. The three breeds clustered with Capra aegagrus as their wild ancestor. Mismatch distribution analysis showed that WAD, RS and haplogroup A have experienced population expansion events. The study has revealed very high diversity within the three breeds which are not strongly separated from each other based on mtDNA analysis. The information obtained on the genetic structure of the breeds will be useful in planning improvement and conservation programs for the local populations.

Application of multivariate logistic regression model to assess factors of importance influencing prevalence of abortion and stillbirth in Nigerian goat breeds

The aim of the study was to investigate the application of binary logistic regression to assess the potential factors associated with the prevalence of abortion and stillbirth in indigenous goat breeds in Nasarawa State, north central Nigeria. 5,268 kidding records of does from a total of 105 traditional goat herders from the year 2010-2011 were utilized in the study. The goats which were of West African Dwarf (WAD), Red Sokoto (RS), Sahel (SH) and WAD x RS crossbred (WR) genetic groups originated from different flocks and were reared under the traditional extensive system. The risk factors investigated were dam breed group, season, parity and number of foetuses. Of the 5,268 kidding records, 570 (10.8%) and 520 (9.87%) were cases of abortion and stillbirth, respectively. The logistic regression analysis revealed that season, parity and number of foetuses were the parameters of utmost importance (P&lt;0.05) influencing the prevalence of abortion and stillbirth in the four genetic groups investigated. The logistic regression models were able to predict correctly 89.2 and 90.1% cases of abortion and stillbirth, respectively. The present information may be exploited in management practices to attenuate the incidence of abortion and stillbirth parturition, thereby increasing the productivity of the animals.