Blackhead Persian Sheep Research Articles

Sheep supplementation in the arid and semi-arid areas of northern Kenya

The objective of this study was to assess the effects of partial supplementation of 1.5 years old blackhead Persian sheep with hay, molasses and local salt (Chalbi salt). The nutritive values of hay, molasses and Chalbi salt were determined. The selected sheep were assigned to three treatments in a completely randomized design; 10 sheep were given to the farmer and were herded based on his management practice (denoted as treatment A), 10 were grazed for 5 h and later supplemented with 600 g of chopped hay mixed with molasses per sheep daily and Chalbi salt ad libitum (denoted as treatment B), 10 were introduced to a government research farm, Kenya Agricultural and Livestock Research Organization (KALRO-Marsabit) flock and managed on the free range with no supplementation except Chalbi salt. They were also grazed for 8 h daily (denoted as treatment C). Feed resources for partial supplementation were analysed for proximate analysis, Van soest, in-vitro dry matter digestibility and mineral profiles. Molasses was spread on hay to increase palatability and intake. Chalbi salt was provided ad libitum to the supplemented group. All 30 sheep were weighed weekly. The data on sheep weights were analyzed using Statistical Package for Social Sciences (SPSS). The mean sheep weight over the study period was higher among the supplemented group B (25.95 kg), followed by on-station research farm-managed group C (22.60 kg) and lastly farmer-managed group A (19.50 kg). Supplementation of sheep using local feed resources enhances weight gain and this is recommended, essentially in a weight-based marketing system. Keywords: Market, nutrients, sheep, supplement, weight.

Genetic Basis of Dorper Sheep (Ovis aries) Revealed by Long-Read De Novo Genome Assembly.

Dorper sheep (Ovis aries) (DPS), developed in the 1930s by crossing Dorset Horn and Blackhead Persian sheep in South Africa, is a world-famous composite breed for mutton production. The genetic basis underlying this breed is yet to be elucidated. Here, we report the sequencing and assembly of a highly contiguous Dorper sheep genome via integration of Oxford Nanopore Technology (ONT) sequencing and Hi-C (chromatin conformation capture) approaches. The assembled genome was around 2.64 Gb with a contig N50 of 73.33 Mb and 140 contigs in total. More than 99.5% of the assembled sequences could be anchored to 27 chromosomes and they were annotated with 20,450 protein-coding genes. Allele-specific expression (ASE) genes of Dorper sheep were revealed through ASE analysis and they were involved in the immune system, lipid metabolism, and environmental adaptation. A total of 5,701 and 456 allelic sites were observed in the SNP and indels loci identified from relevant whole-genome resequencing data. These allelic SNP and INDEL sites were annotated in 1,002 and 294 genes, respectively. Moreover, we calculated the number of variant sites and related genes derived from the maternal and paternal ancestors, revealing the genetic basis of outstanding phenotypic performance of Dorper sheep. In conclusion, this study reports the first reference genome of Dorper sheep and reveals its genetic basis through ASE. This study also provides a pipeline for mining genetic information of composite breeds, which has an implication for future hybrid-breeding practices.

Prion protein (PrP) gene polymorphism in Red Maasai and Black Head Persian sheep breeds in Tanzania: Consistent profile regardless of locations

The status of scrapie in Africa is largely unknown. The susceptibility to scrapie and its pathology is determined by amino acid polymorphisms at positions 136 (A/V), 154 (R/H) and 171 (Q/R/H) of the ovine PrP gene (PrP genotype) of the animals. Despite the widely studied PrP gene polymorphisms worldwide, limited data is available on PrP genotypes of sheep from the African continent. Previously, we have reported six PrP genotypes derived from four different alleles in Red Maasai and Black Herd Persian (BHP), the ARQ/ARQ genotype being more frequent in the Red Maasai than in the BHP sheep. The highly susceptible VRQ allele was not found in any of the sheep breeds; the ARR allele was absent in the Red Maasai or occurred at a low frequency in the BHP. The lack of the highly susceptible VRQ alleles among Tanzanian sheep examined, necessitated further examinations on genetic susceptibility in sheep of the same breeds, but originating from an entirely different part of Tanzania. Consistently, ARQ/ARQ genotype was observed in 88% of Red Maasai and 64% of BHP sheep, ARQ/AHQ genotype was present in 12% in Red Maasai and 36% in BHP. Neither the highly resistant (ARR/ARR), nor the highly susceptible (VRQ/VRQ) genotypes were found. The ARQ and AHQ were the only alleles observed. The ARQ allele constituted 94%, 82% and 67% in the Red Maasai, BHP and cross-bred sheep, respectively. The AHQ constituted 6%, 18% and 33%, respectively. Data reported here, provide additional information on genetic susceptibility of the Red Maasai, BHP and their crosses; they may be helpful in policy formulation for future prevention of scrapie.

Genotyping of the prion protein (PrP) gene in Red Maasai and Black Head Persian sheep in Tanzania

Susceptibility to scrapie in sheep is largely influenced by four polymorphic amino acid positions of the ovine PrP gene at codons 136, 141, 154 and 171. Genotyping of corresponding DNA polymorphism can be used as a basis for selection decisions. A total of 100 Red Maasai and 79 Black Herd Persian sheep, representative of the widely distributed breeds in Tanzania, were genotyped by real-time PCR. Genomic DNA was extracted from buccal epithelial cells. We report six genotypes derived from four different alleles, with the ARQ/ARQ genotype being more frequent ( p = 0.0081) in the Red Maasai than in the Black Head Persian sheep. Our study also demonstrated higher allelic frequency ( p = 0.00055) of the ARQ in the Red Maasai than in Black Head Persian sheep, while the AHQ allelic frequency was higher ( p = 0.00086) in the Black Head Persian. All the animals were homozygous LL 141. The highly susceptible VRQ allele was not found in any of the sheep breeds examined in this study. Both breeds were genetically low-level resistant to scrapie (NSP3). Due to absence or very low frequency of the ARR allele in the two breeds, selection for genetic resistance to scrapie through an increase of the ARR allele does not seem very relevant. If new breeds of sheep are to be introduced for crossbreeding in Tanzania, care should be taken to avoid import of the VRQ allele. To our knowledge, this is the first study exploring the PrP genotypes in sub-Saharan African sheep and in the Red Maasai and Black Head Persian sheep breeds in particular. The data provide base-line information on genetic susceptibility of the two sheep breeds to scrapie, which may be useful in policy formulation for prevention and future research on prion diseases.

Effect of tanniniferous browse meal on nematode faecal egg counts and internal parasite burdens in sheep and goats

The effect of tanniniferous browse meal on faecal egg counts (FEC) and intestinal worm burdens was investigated in sheep and goats infested experimentally with gastrointestinal nematodes. Initially, leaves of different browse tree species were assayed for condensed tannin (CT) content using a colorimetric method to determine concentration and seasonal variations. The level of CT in the leaves ranged between 58 – 283 g/kg dry matter. Seasonal changes in CT levels were influenced by stage of leaf maturity with peak levels after the wet season in June. Leaves of Acacia polyacantha had the highest tannin concentration and were used to test their anthelmintic effect in goats and sheep infested with the nematodes in two separate feeding trials. In Trial 1 an acacia leaf meal supplement (AMS) was offered at 100 – 130 g/animal/day for 20 days to growing Small East African goats to investigate its effect on FEC and worm burden. Mean FEC and worm burden of the AMS-fed group were respectively 27% and 13% lower than in the control group. Trial 2 was similar to Trial 1 except that AMS was offered for 30 days to growing Black Head Persian sheep at 170 g/animal/day. The sheep receiving AMS showed a slight reduction in FEC (on average 19% lower than the control group) but had no effect on worm burden. The current results substantiated previous reports of a suppressing effect of CT on gastrointestinal nematodes of small ruminants. Although the observed anthelmintic activity of AMS was less than expected, such reductions can have practical epidemiological implications in reducing pasture larval contamination. Further studies are needed under field conditions to evaluate the feasibility of using locally available tanniniferous browse as an alternative to synthetic anthelmintics in reducing worm infestations in small ruminants. South African Journal of Animal Science Vol. 37 (2) 2007: pp. 97-106

A systems analysis of inter-annual changes in the pattern of sheep flock productivity in Tanzanian livestock research centres

Annual estimates of production traits over a 22 year period (1965–1987) for Black Head Persian sheep (BHP) from Malya and West Kilimanjaro research centres in Tanzania were utilized to analyse variation of flock productivity over time. Principal component analysis indicated major trends in the variation of trait combinations, while cluster analysis was used to identify years with similar patterns in the combination of traits. The paper discusses the historical pattern which is identified. It appears that productivity patterns were only weakly related to ecological changes, but were more strongly related to management factors. The approach and analytical technique employed are recommended as tools in livestock systems diagnostic research.

Comparative water consumption and efficiency in three divergent sheep types

SUMMARYCumulative feed and water intakes and body weights of 30 growing ewe lambs of three different breeds were recorded weekly for 34 weeks between October 1990 and June 1991 at the Experimental Farm of the University of Pretoria. The results were analysed to obtain water efficiencies on both an absolute and metabolic weight gain basis. On an absolute basis, Mutton Merino sheep consumed 145% and Dorper 109% more water than Blackhead Persian sheep. On a metabolic weight gain basis, the corresponding differences were 92 and 66%, respectively. Mutton Merino and Dorper lambs also consumed 69 and 41% more water per kg feed intake than the Blackhead Persians, respectively. Weekly water consumption increased twice as much per 1 °C increase in ambient temperature in the Dorper and Mutton Merino lambs as in the Blackhead Persians. These results suggest that sheep of the Blackhead Persian, and probably also other indigenous breeds, balance their water requirements at a more economical level and would be a more appropriate choice than those breeds currently being managed in sustainable sheep production systems in areas where water availability is limited.

Alternative use of Karakul sheep for pelt and lamb production in Botswana. I. Reproduction and growth performance

Performance data of 9800 Karakul, Namaqua Africander, Blackhead Persian sheep and their various crosses were collected from July 1986 to September 1987 in the Southern Kalahari desert of Botswana. Karakul lambs may be used either for pelt (Persian lamb) or for meat production. The purpose of this study was to assess the overall productivity of Karakul sheep and their crosses with local mutton breeds for producing both pelts and lambs for meat. Annual number of lambings per ewe averaged 1.39, litter size 1.007. In flocks with predominantly Karakul breeding, 43% of Karakul lambs were slaughtered for pelt production. Body weight of ewes in the first month post-partum was 40.8 kg, lamb weight at 150 d was 27.4 kg. Neither genotype nor management class had a significant influence on the annual number of lambings per ewe, or body weight of ewe and lamb. Season of birth, lambs being pelted or reared, and flock-within-management class had significant effects on these traits. During the study period, 13.2% of lambs were recorded as having died, 6.4% were home slaughtered, 18.0% sold and 8.0% of all disposals could not be traced; for adult sheep, the corresponding rates were 4.3%, 3.7%, 12.5% and 5.6%, respectively. Average flock productivity was estimated to be 27.7 kg lamb per ewe and year, 0.67 kg lamb per kg ewe and year, and 1.71 kg lamb per kg 0.75 ewe and year.

Effects of replacing sunflower seed cake with Crotalaria ochroleuca hay on feed intake, digestibility and growth rate of grazing sheep

Sixteen Blackhead Persian sheep were fed four rations containing four levels of Crotalaria ochroleuca (“marejea”) hay at 0, 15, 30 and 45% and sunflower seed cake (SSC) at 0, 10, 20 and 30%, as a supplement to grazing 8 h/d. The four supplemental rations were 30% SSC (T 1), 20% SSC+ 15% marejea (T 2), 10% SSC+30% marejea (T 2) and 45% marejea. In addition, the animals received Rhodes grass hay, maize bran and mineral mixture. Replacement of concentrates (sunflower seed cake and maize bran) with marejea hay reduced ration dry matter and crude protein digestibilities from 63.7 to 54.5% and from 72.6 to 59.4%, respectively ( P < 0.05). Dry matter, organic matter and crude protein intake (g/d) decreased as hay level increased ( P < 0.05). Growth rates decreased from 84.4 to 56.7 g/d ( P < 0.05) between T 1, T 2, T 3 and T 4 as level of marejea hay increased. There was no significant difference ( P > 0.05) between rations containing marejea. Daily N retention decreased from 6.4 to 5.3 g/d as level of marejea substitution for sunflower seed cake increased. Controls (T 1) had high ( P < 0.05) retained levels of N. It was concluded that marejejea indigenous legume that grows wild in Tanzania can be used to replace sunflower seed cake in rural areas where the cake is not available and labour is cheap.

Comparative performance of Landim and Blackhead Persian sheep in Mozambique

Larger litter sizes of Landim sheep (1.38 lambs per parturition) compared to Blackhead Persian (BHP) (1.00) and BHP X Landim (1.00), and similar parturition intervals in each genotype (342 days) resulted in greater annual output of young in the Landim (1.71) than in BHP (1.17) or in BHP x Landim (1.25). Weights of all three genotypes were similar at birth (2.5 kg), at 90 days (12.5 kg), at 150 days (15.0 kg) and at 365 days (28.1 kg). Breed did not affect the death rate at any of 10 days (4.9%), 30 days (6.7%), 90 days (11.9%) or 150 days (19.6%) of age. Output of weaned lambs per breeding ewe per year was slightly (P< 0.1) higher in crossbred (23.3 kg) than in Landim (19.7 ) or BHP (19.4 kg) but output per kg live weight of ewe (488 g) and per kg 0.73 live weight of ewe (1.36 kg) did not differ among the genotypes. Year, season, type of birth, sex and ewe age significantly influenced most traits. Overall performance of Landim sheep was not different to that of the BHP indicating little if any advantage in using BHP. Landim sheep have large litter sizes in comparison to other African indigenous breeds and could themselves be used to improve reproductive performance of other strains of sheep.

The nutritive value of ensiled forages cut at three stages of growth

Twelve male adult Black Head Persian sheep were used in a digestibility and feed intake trial to evaluate maize, guinea grass and jaragua grass silages. The forages were cut at the pre-anthesis, anthesis and post-anthesis stages of growth. Dry matter (DM), pH and ammonia nitrogen of the silages were also determined. Maize silage had a lower mean pH than the 2 grass silages. The organic matter digestibility (OMD), crude protein digestibility (CPD) and crude fibre digestibility (CFD) were higher in maize silage than in the 2 grasses. Guinea grass silage had a significantly ( P < 0.01) higher OMD, CPD and CFD than jaragua grass silage. Silages made from herbage harvested at the pre-anthesis stage had a significantly ( P < 0.01) higher OMD, CPD and CFD than those made from herbage harvested at the post-anthesis stage of growth. Maize silage was superior at all stages of growth, except at pre-anthesis, to the 2 grass silages. Both jaragua and guinea grass produced good silage when herbage was harvested at the pre-anthesis and anthesis stages of growth.

Phagocytosis of Erythrocytes and Leucocytes in Sheep Infected with Trypanosoma congolense (Broden 1904)

Observations on the haematology and histopathology of T. congolense infection in Blackhead Persian sheep provided evidence of erythrocyte and leucocyte phagocytosis on a large scale throughout the reticuloendothelial tissues. It is postulated that this phenomenon contributed substantially to the anaemia that developed in the course of the disease and might have been the prime factor. Possible causes of this phagocytic activity include (i) the coating of cells with parasitic antigen, (ii) the production of defective cells and (iii) an auto-immune reaction.

Volatile fatty acids in the rumen of African sheep given a variety of low-protein diets

SUMMARY1. Total concentrations of volatile fatty acids and molar proportions of acetic, nrooionic and butyric acids were determined in the rumen of Blackhead Persian sheep given sixteen low-protein diets.2. Total concentrations of acids ranged from 2·89 to 9·33 millimoles/ 100 ml. of rumen liquor. Both digestibility and protein content of the ration had a significant effect on the concentration of volatile fatty acids in the rumen liquor. Protein content of the diet probably influenced the latter through controlling the rate of ruminal fermentation.3. Molar proportions of acetic acid varied from 59·7% to 69·3%, of propionic acid from 21·2% to 29·6%, and of butyric plus higher acids from 7·6% to 16·3%. Protein content of the diet had no significant effect on the composition of the acid mixture, but organic matter digestibility was inversely related to the proportion of acetic acid.4. The fermentation in the rumen of Blackhead Persian sheep, as judged by the volatile fatty acids produced, appears to be similar to that found in European breeds of sheep.