Crossing Merino and a coarse wool breed of sheep; a study of the birthcoat of lambs

Guirgis, R. A.

doi:10.1017/s0021859600034869

Cited by 6 publications

(6 citation statements)

References 17 publications

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“…In the present material, plateau arrays were less frequent in Barki than reported earlier (Guirgis, 1977) and the | M lacked fine arrays (ravine).…”

Section: Discussioncontrasting

confidence: 73%

“…Barki showed more frequent arrays with precipice, percentages were 54-2 and 8-3 in Barki and f M respectively. Guirgis (1977) reported higher values of precipice encountered earlier in the same flock; percentages were 97-4, 74-4 and 62-5 in Barki (farmers), Barki (experimental) and f M respectively. The higher frequency of saddle array might have accounted for the lower frequency of precipice encountered in the present Barki material.…”

Section: Discussionmentioning

confidence: 81%

“…On the assumption that the precipice occurs between primary and secondary fibres Guirgis (1977) estimated the S/P ratio, at birth, from birthcoat fibre type frequencies, in arrays with precipice, in the same flock and reported values of 1-36 and 1-14 in Barki and | M saddle array. Values encountered in the present study, from skin sections were 1-36 and 2-52 in Barki and f M respectively.…”

Section: Discussionmentioning

confidence: 99%

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Post-natal development, dimensions of the skin follicle population and birthcoat follicular origin in Barki and ⅜ Merino lambs

et al. 1981

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In a study of two breed groups, coarse wool Barki and f Merino f Barki, data were obtained on skin histology from birth to the age of 1 year, birthcoat fibre type arrays and fibre-follicle relationship.The | Merino exceeded Barki lambs in the maximum S/P ratio, values of which were 3-40 and 5-64 obtained at 6 and 8 months in Barki and § Merino respectively.Internal diameters of primary follicles ranged from 39-0 to 64-7 and from 41-0 to 56-8 fim; those of secondaries ranged from J9-8 to 34-9 and from 22-6 to 33-3 fim in Barki and f Merino respectively.The ratio of primary to secondary follicle diameters showed high values in both breed groups; averages were 1-89 and 1-71 for internal diameter and 1-86 and 1-71 for external diameter in Barki and f Merino respectively.Birthcoat fibre type arrays were mostly saddle, only 8-3 % were plateau (P 3 ) in both breed groups.

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“…In the present material, plateau arrays were less frequent in Barki than reported earlier (Guirgis, 1977) and the | M lacked fine arrays (ravine).…”

Section: Discussioncontrasting

confidence: 73%

Section: Discussionmentioning

confidence: 81%

Section: Discussionmentioning

confidence: 99%

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Post-natal development, dimensions of the skin follicle population and birthcoat follicular origin in Barki and ⅜ Merino lambs

et al. 1981

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“…Though differences were observed in the birthcoat of saddle array, with precipice and with transition, in the different breed groups, corresponding differences were not found in their adult fleeces. In earlier work (Guirgis, 1977) Barki lambs, that belonged to farmers where no breeding programme was followed, had birthcoats with 48 and 52 % of the fibre type arrays as plateau and saddle, respectively. In the experimental flock only 18% of the birthcoat fibre type arrays were plateau.…”

Section: Discussionmentioning

confidence: 99%

“…I t has been reported (Guirgis, 1973 a) that 30% of the skirted Barki fleeces could be sorted for carpet wool yarns, whereas the rest could be used in apparel. In the Barki material, very few SK's in parallel were reported in some plateau (P 3 ) arrays (Guirgis, 1977) indicating the weakness of the base, a basic drive towards coarseness and medullation (Dry, 1965). This, together with the shortage of available feed for most of the year, where the annual seasonal rainfall averages 150 mm, means that the local Barki wool can be developed towards the apparel type.…”

Section: Discussionmentioning

confidence: 99%

Lamb birthcoat relationship to the adult fleece in Merino, coarse wool Barki and Merino × Barki sheep crosses

Guirgis

1982

J. Agric. Sci.

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The present study was carried out on adult fleeces, of Merino, coarse wool Barki and five of their crosses, of known birthcoats. The adult fleece traits studied were clean fleece weight, mean fibre diameter and its variability and mean staple length and its variability.Birthcoat-adult fleece relationship was dependent on the breed studied. In Barki, plateau array in the birthcoat developed to adult fleeces with higher values of mean fibre diameter and its variability, mean staple length and clean fleece weight than those with saddle array. In £ Merino there was a gradient in staple length, running from plateau, via saddle, to ravine, with higher values of the coarser arrays. Differences occurred in variability of fibre diameter between plateau and saddle arrays in § and $ Merino and between saddle and ravine in £, $ and J Merino.Differences occurred where birthcoats, with plateau array with precipice, in the curly-tip group, grew into adult fleeces with longer mean staple than those with transition in Barki sheep. In the other breed groups differences observed in saddle array, with different features, precipice or transition, at the birthcoat level, did not contribute differences in their adult fleeces.Selection of Barki lambs with plateau fibre type array in their birthcoats would result in higher clean adult fleece weights that have coarser fibre diameter, with higher variability, and longer staple than those with saddle array. Within saddle array, selection of those with reduced SK % would develop into adult fleeces with higher clean fleece weight and those with reduced CT% would grow into adult fleeces with finer diameter.Selection of lambs that have birthcoat ravine array in f, £, f and f Merino would reduce the within-staple variability in their adult fleece fibre diameter. TNTROTVTTfTTOTSrt n e P re dictive value of the birthcoat for early selection of adult fleece characteristics. Crossing indigenous coarse wool breeds with Merino is widely used as a method of improving MATERIALS AND METHODS wool production, the value of which is considerable under semi-arid conditions. Study of birthcoat fibre Lambs were sampled for the birthcoat at the age type arrays has been developed to establish a rela-of 2-5 weeks from the standard back position, and tion with characteristics of the adult fleece for use the whole fleeces of the same animals were taken at as an aid to early selection. Assessment of fibre the first shearing (16 months of age). The study was type arrays of lambs' birthcoats has proved an carried out on fleeces produced in the shearing efficient method in early selection against successive seasons 1970-3 from Barki (BB), JMerino-f Barki generations of kemp in the adult fleece but (|M),JMerino-^Barki (JM),$Merino- §Barki (fM), sufficient information on the relation between birth-f Merino-J Barki (£M) and Merino (MM). Fleeces coat and adult fleece traits (diameter, staple were skirted and the weight of each component, length and wool production) in different breeds is the fleece wool and the skirtings, w...

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The study of kemp succession in the adult fleece of two coarse-wool breeds of sheep in relation to the birthcoat

1979

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A study of the birthcoat and its relation to kemp succession in the adult fleece of coarse-wool Awassi and Hamdani sheep was carried out, as an aid to early selection. Lambs were covered, at the age of 2 months up to 15 months, by fixing patches of canvas on six body positions.Both Awassi and Hamdani birthcoats had high halo hair grades. The animals played the dominant role in affecting different traits of the birthcoat which indicated the importance of genetic factors in further development of the birthcoat. The birthcoat of both types of lambs showed only coarse (plateau) and less coarse (saddle) fibre type arrays.Hamdani had more kemp as G t and G 2 (first and second generations respectively) than Awassi sheep. The shed G x following the different fibre type arrays, showed some overlapping between plateau and saddle. The same arrays of the birthcoat behaved differently on the different positions, where generally the anterior positions had less kemp than those posteriorly. Percentages of shed fibres were 100, 17-14, 2-38 and 0-35 of halo hairs, super sickles, sickles and chalky curly tips respectively in Awassi. Corresponding figures were 100, 29-26, 5-87 and 7-73 in Hamdani. In Awassi, halo hairs, of the birthcoat, showed a relatively high correlation (P < 0-01) with G 1 kemp on the hip and britch. Within saddle array, in Awassi, the correlation between halo hairs and G x kemp showed the highest values (P < 0-01), whereas in Hamdani the correlation between super sickles in the birthcoat and G 2 kemp showed medium values (P < 0-05).Selection of high halo hair grade lambs, in the birthcoat, that have saddle arrays, with high percentage of sickle fibres in Awassi and with low percentage of super sickles in Hamdani, would result in low percentages of kemp in the adult fleece. High halo hair grades would be necessary for early survival of lambs. INTRODUCTION MATERIALS AND METHODS

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Crossing Merino and a coarse wool breed of sheep; a study of the birthcoat of lambs

Cited by 6 publications

References 17 publications

Post-natal development, dimensions of the skin follicle population and birthcoat follicular origin in Barki and ⅜ Merino lambs

Post-natal development, dimensions of the skin follicle population and birthcoat follicular origin in Barki and ⅜ Merino lambs

Lamb birthcoat relationship to the adult fleece in Merino, coarse wool Barki and Merino × Barki sheep crosses

The study of kemp succession in the adult fleece of two coarse-wool breeds of sheep in relation to the birthcoat

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