• Genomics & Informatics
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• v.10 no.3
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• pp.200-205
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• 2012

Although a large number of single nucleotide polymorphisms (SNPs) have been identified from the bovine genome-sequencing project, few of these have been validated at large in Bos indicus breeds. We have genotyped 192 animals, representing 5 cattle populations of Ethiopia, with the Illumina Bovine 8K SNP BeadChip. These include 1 Sanga (Danakil), 3 zebu (Borana, Arsi and Ambo), and 1 zebu ${\times}$ Sanga intermediate (Horro) breeds. The Hanwoo (Bos taurus) was included for comparison purposes. Analysis of 7,045 SNP markers revealed that the mean minor allele frequency (MAF) was 0.23, 0.22, 0.21, 0.21, 0.23, and 0.29 for Ambo, Arsi, Borana, Danakil, Horro, and Hanwoo, respectively. Significant differences of MAF were observed between the indigenous Ethiopian cattle populations and Hanwoo breed (p < 0.001). Across the Ethiopian cattle populations, a common variant MAF (${\geq}0.10$ and ${\leq}0.5$) accounted for an overall estimated 73.79% of the 7,045 SNPs. The Hanwoo displayed a higher proportion of common variant SNPs (90%). Investigation within Ethiopian cattle populations showed that on average, 16.64% of the markers were monomorphic, but in the Hanwoo breed, only 6% of the markers were monomorphic. Across the sampled Ethiopian cattle populations, the mean observed and expected heterozygosities were 0.314 and 0.313, respectively. The level of SNP variation identified in this particular study highlights that these markers can be potentially used for genetic studies in African cattle breeds.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.12
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• pp.1718-1734
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• 2009

The aim of this review is to address some characteristics that influence meat quality. Genetic groups, nutrition, finishing systems and gender are the major factors that change carcass characteristics, chemical composition and fatty acid profile. Genetic groups that have zebu genes in their composition show higher hot carcass dressing than genetic groups without zebu genes. Genetic groups that have European breeds in their composition have higher marbling scores. On the other hand, genetic groups that have zebu breeds show low marbling scores. Bulls finished in feedlots present higher final weight than steers, cull cows and heifers. Fat thickness is one of the principal parameters that are affected by different gender. Cull cows (4.72 mm) and heifers (4.00 mm) present higher values than bulls (1.75 mm) and steers (2.81 mm). The major effects observed by different systems of termination are fat thickness and marbling. Crude protein presents variation due to nutrition. Nutrition influences variation of fatty acid profile. Genetic groups also influence fatty acid profile. Genetic groups that have zebu genes in their composition show high percentage of PUFA. The major class of fatty acids that is changed with nutrition is PUFA. The better ratios of PUFA/SFA and n-6/n-3 are found in Longissimus muscle of animals finished in pasture systems.

• Animal Bioscience
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• v.35 no.7
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• pp.955-963
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• 2022

Objective: The aim of this study was to estimate genetic parameters for 305-day cumulative milk yield and components, growth, and reproductive traits in Guzerá cattle. Methods: The evaluated traits were 305-day first-lactation cumulative yields (kg) of milk (MY305), fat (FY305), protein (PY305), lactose (LY305), and total solids (SY305); age at first calving (AFC) in days; adjusted scrotal perimeter (cm) at the ages of 365 (SP365) and 450 (SP450) days; and adjusted body weight (kg) at the ages of 210 (W210), 365 (W365), and 450 (W450) days. The (co)variance components were estimated using the restricted maximum likelihood method for single-trait, bi-trait and tri-trait analyses. Contemporary groups and additive genetic effects were included in the general mixed model. Maternal genetic and permanent environmental effects were also included for W210. Results: The direct heritability estimates ranged from 0.16 (W210) to 0.32 (MY305). The maternal heritability estimate for W210 was 0.03. Genetic correlation estimates among milk production traits and growth traits ranged from 0.92 to 0.99 and from 0.92 to 0.99, respectively. For milk production and growth traits, the genetic correlations ranged from 0.33 to 0.56. The genetic correlations among AFC and all other traits were negative (-0.43 to -0.27). Scrotal perimeter traits and body weights showed genetic correlations ranging from 0.41 to 0.46, and scrotal perimeter and milk production traits showed genetic correlations ranging from 0.11 to 0.30. The phenotypic correlations were similar in direction (same sign) and lower than the corresponding genetic correlations. Conclusion: These results suggest the viability and potential of joint selection for dairy and beef traits in Guzerá cattle, taking into account reproductive traits.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.5
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• pp.751-756
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• 2002

A study was carried out to evaluate the incidences and causes of bovine mastitis in Tanzanian shorthorn zebu (Bos indicus) in the traditional sector and crossbred cows (Bos taurus${\times}$Bos indicus) in the dairy ranching sector, both found under the extensive range management system. Management practices were evaluated through a survey study using structured questionnaires. A total of 120 lactating cows (60 cows from each sector) were screened for the disease using the California Mastitis Test (CMT). Confirmatory tests used for infected cows included; the Direct Microscopic Somatic Cell Count (DMSCC), culture, bacteriological and biochemical laboratory assays. Survey results showed that management practices were generally very poor in both sectors with 84% of the surveyed herds being kept and milked under very unhygienic environmental conditions. The level of infection was higher in the crossbred cows (5% clinical and 38.3% sub-clinical mastitis) and lower in the zebu cows with only sub-clinical mastitis (23.3%). Crossbred cows had (p<0.05) higher somatic cell counts than zebu cows. The four highest-ranking bacterial isolates in order of importance were Staphylococcus aureus, Escherichia coli, Streptococcus agalactiae and Bacillus spp. It was concluded that bovine mastitis under the extensive management system in Tanzania was a result of poor management practices and that zebu cows were more resistant to the diseases than crossbred cows.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.7
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• pp.898-904
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• 2011

The PCR- restriction fragment length polymorphism (RFLP) in and around TM4 of SLC11A1 gene and its association with the incidences of brucellosis in Hariana breed (Bos indicus) and Holstein Friesian crossbred (Bos indicus${\times}$Bos taurus) cattle was examined. A fragment of 954 bp encoding the TM4 was amplified, and RFLP was identified by digestion of the amplicon independently with AluI and TaqI. The amplicon (GenBank Acc. No. AY338470 and AY338471) comprised of a part of exon V (<59 bp) and VII (62>), and entire intron 5 (423 bp), exon VI (71 bp) and intron 6 (339 bp). Digestion with AluI revealed the presence of two alleles viz, A (281, 255, 79 and 51 bp) and B (541, 255, 79 and 51 bp). The frequency of A allele was estimated as 0.80 and 0.73 in Hariana and crossbred cattle, respectively. Due to presence of a polymorphic TaqI site at intron 5, two alleles: T (552 and 402 bp) and Q (231, 321 and 402 bp) were identified. The frequency of T allele was estimated as 0.96 and 0.97, respectively. For association study, on the basis of serological tests and history of abortion, the animals were grouped into "affected" and "non-affected". However, no association could be established with the observed RFLPs.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.6
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• pp.794-799
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• 2003

A study was conducted on 2102 records of 808 crossbred cows of various genetic groups maintained under 'All India Coordinated Research Project on Cattle' at C C S Haryana Agricultural University, Hisar, over 25 years period (1968-1993) with an objective to assess and compare the amount of percent improvement and heterotic effect for different performance traits in various genetic groups produced under this programme. Survivability sharply and significantly declined from 1/2 to $3/4^th$ bred and further from $3/4^th$ to inter-se bred. This may be due to periodic and management differences in addition to the higher level of exotic inheritance and decreased heterotic effect over the filial generations. Jersey and Holstein Friesian crosses among 1/2 breds and their 50% inheritance among $3/4^th$ and inter-se breds had highest improvement and heterosis in reproduction and production traits respectively. Among inter se bred genetic groups, BFH (I) had no recombination loss in SP and CI, while FJH (I), JFH (I) and FBH (I) had on recombination loss in AFC, LY, LL and PE. The crossbreeding of zebu cows with exotic breeds brings about spectacular improvement in comparison to the performance of zebu breed, while conventional selection over several generation would lead to only modest improvement. In addition to additive effect, there was sufficient heterosis in Jersey crosses for reproduction and Holstein Friesian crosses for production performance. Three breed crosses with exotic inheritance between 50 and 75 percent incorporating genes (25 to 50%) from both of these breeds is the best combination for stabilization.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.9
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• pp.1300-1306
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• 2002

Fourteen non-descript zebu cattle calves of about 1 year and 6 months age and 111 kg average body weight were used in this experiment. Grazing (5 h daily) animals were supplemented with urea-molasses blocks with and without Yucca, while the control group was without any supplementation i.e. grazing only. The feeding trial continued for a period of 70 days (November to February). At the end of trial three animals per treatment were slaughtered to compare carcass traits. Group no. 1 was fed block with yucca, group no. 2 was fed block without yucca and group no. 3 was on grazing only. Block intake was found to be 724 g/h/d and 1,239 g/h/d for group no. 1 and group no. 2, respectively (p<0.05). Feed efficiency of blocks was found to be 2.71 kg and 4.86 kg for group no. 1 and group no. 2, respectively (p<0.05). Block intake per kg $BW^{0.75}$ was found to be 14.75 and 26.05 gram for group 1 and group 2, respectively (p<0.05). Average daily body weight gain was found to be 267 g/h/d, 255 g/h/d and 169 g/h/d for group 1, 2 and 3, respectively. Carcass traits among the three treatments were found to be statistically similar. Thus urea-molasses blocks supplementation improved body weight gain and addition of yucca in the blocks further improved body weight gain, feed efficiency and economics. Environment (ambient temperature, rainfall, wind and humidity) had no significant effect on three treatments.

• Parasites, Hosts and Diseases
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• v.61 no.2
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• pp.127-137
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• 2023

Bovine trypanosomiasis is a significant health concern for livestock intensification in Côte d'Ivoire. This study aimed to determine the prevalence and distribution of pathogenic trypanosomes and identify the most infected cattle breed in northern Côte d'Ivoire. We examined 700 cattle and found that polymerase chain reaction (PCR) was more sensitive (12.3%) than microscopic observation (5.6%). Among the trypanosome species detected in naturally infected cattle, Trypanosoma vivax was 7.3%, Trypanosoma simiae tsavo was 6.7%, and Trypanosoma congolense was 0.4%. The overall prevalence of trypanosome infection in all cattle breeds was 12.3%, while the prevalence in individual breeds was 14.8%, 7.3%, 10.6%, and 12.3% for N'Dama, Baoule, Zebu, and Mere breed, respectively. The infected animals had low packed cell volume, influencing the prevalence. Our findings indicate that bovine trypanosomes are prevalent in Côte d'Ivoire, and their prevalence varies by region and breed. These pathogens include T. vivax, T. simiae tsavo, and T. congolense.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.2
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• pp.301-303
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• 1993

Hematological value were determined from 140 Fasciola gigantica infested and 138 non-infested apparently healthy (control) zebu cattle from eight different sites of Bangladesh. The F. gigantica infested cattle have experienced of normocytic normochromic anemia indicated by the significant (p<0.01) decline of total erythrocyte count, hemoglobin level, packed cell volume and mean corpuscular hemoglobin concentration and significant (p<0.01) increase of erythrocyte sedimentation rate, as compared with non-infested control animals. Values of mean corpuscular volume and mean corpuscular hemoglobin content were not differed significantly between the infested and control animals. There observed significantly (p<0.01) higher eosinophil and neutrophil counts and significantly (p<0.01) lower lymphocyte counts in fasciola infested cattle in comparison with the control animals.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.5
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• pp.603-621
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• 2017

The current review focuses on characterization and conservation efforts vital for the development of breeding programmes for indigenous beef cattle genetic resources in Southern Africa. Indigenous African cattle breeds were identified and characterized using information from refereed journals, conference papers and research reports. Results of this current review reviewed that smallholder beef cattle production in Southern Africa is extensive and dominated by indigenous beef cattle strains adaptable to the local environment. The breeds include Nguni, Mashona, Tuli, Malawi Zebu, Bovino de Tete, Angoni, Landim, Barotse, Twsana and Ankole. These breeds have important functions ranging from provision of food and income to socio-economic, cultural and ecological roles. They also have adaptive traits ranging from drought tolerant, resistance to ticks and tick borne diseases, heat tolerance and resistance to trypanosomosis. Stakeholders in the conservation of beef cattle were also identified and they included farmers, national government, research institutes and universities as well as breeding companies and societies in Southern Africa. Research efforts made to evaluate threats and opportunities of indigenous beef cattle production systems, assess the contribution of indigenous cattle to household food security and income, genetically and phenotypically characterize and conserve indigenous breeds, and develop breeding programs for smallholder beef production are highlighted. Although smallholder beef cattle production in the smallholder farming systems contributes substantially to household food security and income, their productivity is hindered by several constraints that include high prevalence of diseases and parasites, limited feed availability and poor marketing. The majority of the African cattle populations remain largely uncharacterized although most of the indigenous cattle breeds have been identified.