bluuebunny/crossref_metadata_2025_split huggingface dataset:
Age at puberty and possibility of early breeding in Awassi ewes
Authors: Younis A. A. , El-Gaboory I. A. , El-Tawil E. A. , El-Shobokshy A. S. 
Published: March 2009

SummarySixty-four weaned Awassi ewe lambs were used in the present study to estimate age at puberty and to investigate whether early breeding from such ewe lambs is possible. After weaning at 4 months old ewe lambs were divided at random into two experimental groups. One group, designated as moderate, was fed to attain 40 kg live weight at 12 months of age, while the other (high) was planned to reach 50 kg at the same age. Fertile rams were run with the ewe lambs at 6 months of age. Twenty ewe lambs, 10 from each treatment, were slaughtered and their ovaries were examined for the presence of corpora lutea and largest follicles.The overall age at first oestrus was found to be 293 days. Ewe lambs of the high nutritional treatment reached puberty earlier than those of the moderate one (274 v. 312 days). Likewise, single-born lambs reached puberty earlier than twin-born ones (273 v. 312 days). Treatment differences explained 16·5% while type of birth explained 16·3% of the total variance in age at first oestrus. Ewe lambs of the high nutritional treatment experienced more heats than those of the moderate one. Simple correlation coefficients between age at first oestrus and date of birth, daily gain and live weight at puberty were 0·21, 0·09 and 0·75, respectively. Results indicated that ovulation may not occur during the first and second oestrus. From 44 ewe lambs only 12, 10 from the moderate and 2 from the high treatment, lambed 13 viable lambs. Reasons for such a low conception rate (27·3%) are discussed.
Endogenous faecal loss of phosphorus in growing lambs and the calculation of phosphorus requirements
Authors: Braithwaite G. D. 
Published: March 2009

SUMMARYThe endogenous faecal loss of P has been investigated in growing lambs given diets either grossly deficient, moderately deficient or just adequate in P. This loss was found to increase in direct relation to the increased P intake, in spite of the high P requirements of the deficient animals, which suggests that some increased loss with increased P intake is inevitable. Results throw doubt on the validity of the assumption made by the Agricultural Research Council (1980) in their calculations of P requirements, that the endogenous faecal loss of P is maintained at a constant level equal to that which occurs at zero P intake, until requirements are met.Even on the diet which was, according to Agricultural Research Council (1980) recommendations, just adequate in P, lambs were unable to retain the expected amount of P commensurate with their growth. This inability to retain P was not due to a failure of P absorption, since the efficiency of absorption from this diet was higher than the value used by the Agricultural Research Council (1980) in their calculations. Rather, it must have been due to an inevitable endogenous faecal loss of P that was considerably higher than the value assumed by the Agricultural Research Council (1980).It is suggested that in future the value of endogenous faecal loss used in calculations of P requirements is the minimum one that allows a particular requirement to be achieved.
Responses of Yield, Components of Yield and Nutrient Content of Maize to Soil-Applied Zinc in Tropical Rainforest and Savannah Regions
Authors: Kayode G. O. 
Published: March 2009

SUMMARYResults of a 2-year studyin the rainforest and savannah zones of Nigeria todetermine the responses of yield, components of yield and nutrient content of maize to soilapplied zinc showed that Zn significantly increased yield in the new and old savannah soils, whereas significant yield response was recorded only in an old field of the forest zone. Ear weight was the only yield component significantly influenced by Zn treatments in the two zones. Application of 2·5 kg Zn/ha appears adequate for successful maize production in the savannah and old forest zones in the tropics.Soil-applied Zn significantly increased ear-leaf N and Zn, but P concentration was significantly decreased. Grain yield was positively correlated with ear-leaf Zn.
The genetic improvement of Syrian Awassi sheep with special reference to milk production
Authors: Hossamo H. E. , Owen J. B. , Farid M. F. A. 
Published: March 2009

SUMMARYThe improvement of milk production by the establishment of four specialized lines and subsequent within-line selection over a 7-year period under grazing conditions at Kraim station in mid-Syria is described. The specialized line showed a substantially higher total milk production amounting to a mean 25% superiority over the control line in 1979–81.The heritability of total milk yield as estimated from paternal half sib analyses was 0·53 ± 0·169 for 2-year-old ewes and the genetic correlation of a single maximum daily yield record (+ 0·93) with total yield indicates the possibility of simplified selection procedures for this trait.The effect of several other factors (for example, ewe age and season of lambing) on various aspects of lactation in Awassi ewes is reported.
Water stress and time of floral initiation in pearl millet
Authors: Mahalakshmi V. , Bidinger F. R. 
Published: March 2009

SUMMARYThe interaction of water stress and time from sowing to floral initiation was investigated in the field with pearl millet hybrid BJ 104. Extended daylength was used to delay panicle initiation (PI) and flowering (FL) of crops exposed to single periods of mid-season drought. Growth, yield and yield components were related to the number of days for PI and FL in both irrigated and water-stressed treatments. Delay in PI resulted in more leaves and tillers per plant, and greater leaf area, height and total dry matter. Grain yield, however, was not affected resulting in lower ‘harvest index’. There was, however, an increase in the grain yield of main shoots which was offset by a proportional decrease in the grain yield of tillers.Water stress effects were dependent on the physiological stage of the crop at which stress occurred, as a result of the photoperiod treatments. Water stress prior to panicle initiation did not affect the grain yield of the main shoot but increased tiller grain yield, resulting in a higher total (crop) grain yield. Water stress during panicle development reduced the grain yield on the main shoot but this loss was compensated by the grain from the increased number of tiller panicles which reached flowering. Water stress during flowering and grain filling reduced grain yields of both main shoot and tillers, making this the most sensitive stage. Photoperiodic control of floral initiation can provide an escape mechanism to avoid the coincidence of mid-season water stress with sensitive periods of growth.
Comparative study of oestrous activity in Finn ewes and two Egyptian fat-tailed sheep under subtropical conditions
Authors: Aboul-Naga A. M. , Aboul-Ela M. B. , Hassan Ferial A. 
Published: March 2009

SUMMARYOestroua activity of three flocks of Ossimi (O) and Rahmani (R) subtropical fattailed and imported Finn (F) ewes was followed over a calendar year under the prevailing subtropical conditions in Egypt.Rahmani had quite consistent oestrous activity throughout the year, with a slight drop in March and June, and may be regarded as a non-seasonal breed. Oestrous activity of the O ewes was lower than the R at different times of the year. They showed high individual variation. Most of the O ewes had an anoestroua period during July–September but had regular oestrous activity during their breeding season.Overall number of oestruses per ewe per year was 15·9, 13·0 and 10·3 for R, O and F, respectively. Normal cycle length tended to be longer, though not significantly so, in both R and O subtropical breeds than the F (17·8 and 17·6v. 17·1 days). Heat duration was significantly longer in F (47·0 h) than in both local breeds (37·7 and 37·5 h for R and O, respectively).
Developmental characteristics of grass varieties in relation to their herbage production: 3. Tiller development in Dactylis glomerata and Loliutn perenne in relation to head emergence
Authors: Davies I. 
Published: March 2009

SummaryFeatures of the gross morphology of primary growth of Dactylis glomerata and Lolium perenne, and associated changes in digestibility are described.Species differences were noted with regard to the relationships between head emergence and the time when stem apices were raised to defoliation height, vegetative/ reproductive tiller ratios, and tiller size.Also there were differences in the sequence of extension growth of leaf sheaths, internodes and inflorescence leading to emergence of the head. Associated changes in the vertical distribution of leaf blades were examined.In perennial ryegrass extension growth of the inflorescence continued after emergence had begun, but not in cocksfoot. Weight increments in the inflorescence, from emergence onward, followed the same pattern in the two species, however.Differences in the developmental patterns of the two grasses did not appear to influence their relative digestibility.Upper internodes of reproductive tillers of S. 24 ryegrass declined rapidly in digestibility Species differences, and the pattern of changes in the digestibility of lower and upper parts of reproductive tillers are discussed in relation to mechanical aspects of sward development and micro-environmental effects.
The effect of calcium nutrition on the incidence of internal rust spot in the potato
Authors: Collier G. F. , Wurr D. C. E. , Huntington Valerie C. 
Published: March 2009

SummaryTubers produced by potato plants grown in vermiculite and supplied with either 0, 1 or 3 mM calcium chloride solution developed brown necrotic lesions of internal rust spot. Plants supplied with 9 and 27 mM calcium chloride solution did not show the symptoms and had a substantially greater concentration of calcium in the tuber dry matter. It is concluded that internal rust spot is a physiological disorder associated with a low concentration of calcium in the affected tubers.
Control of reproductive and pelt changes in ferrets: some experiments with animals kept entirely upon artificial light
Authors: Hammond J. 
Published: March 2009

The effects, on induction and maintenance of oestrus and on pelt changes, were compared for various schedules of entirely artificial light of constant intensity.A period of exposure to low environmental temperature was without effect on subsequent response to light treatment.In one experiment, after periods on 6 hr. artificial light or on daylight, groups were put upon, daily, (i) 7 hr. light as 6 hr. + 5 hr. dark + 1 hr. light, (ii) the same total amount of light but divided as 6 hr. + 1 hr. separated by darkness increasing by 5 min. each day, and (iii) light increasing from 7 hr. by 5 min. daily. Groups (ii) and (iii) became oestrous together, later than group (i).Subsequently all were placed on 7 hr. total light daily, applied in various ways. If given as a single continuous period daily, oestrus ended and moult into winter coat occurred. The latent period depended upon the treatment previously imposed. The duration of oestrus on treatment (i) was greater than normal.In another experiment females were put on, daily, (iv) 24 hr. light, (v) 14 hr. light, and (vi) 4 hr. light as 2 hr. + 10 hr. dark + 2 hr. light. First response was seen on (vi), but on the average the quickest was on (v) and slowest on (iv). Thus darkness contributes to the induction of oestrus.Possible interpretations are discussed.
The effects of dazomet and fertilizer nitrogen on field beans (Vicia faba L.)
Authors: McEwen J. , Salt G. A. , Hornby D. 
Published: March 2009

SummaryThe mean yield of field beans grown for three consecutive years on a site infested with migratory nematodes was 1540 kg grain/ha in untreated soil and 1870 kg/ha in soil treated with dazomet.Fertilizer nitrogen in amounts up to 250 kg N/ha decreased yield to 990 kg in untreated soil but increased it to 2220 kg in soil treated with dazomet. Fertilizer nitrogen did not affect nematode numbers or root blackening but decreased nodulation and increased mycorrhizal infection by Endogone sp. in untreated soil. Dazomet greatly decreased migratory nematodes of the genera Tylenchorhynchus and Trichodorus and eliminated Pratylenchus. It had little effect on root blackening in the top 10 cm of soil but decreased it in the next 10 cm. Infection with Endogone was almost eliminated.
Intra-varietal variability and response to single plant selection inGossypium hirsutumL.: I. Phenotypic variability
Authors: Thomson N. J. 
Published: March 2009

SummaryPopulations of spaced plants of each of the four American upland cotton varieties Deltapine Smooth Leaf, Rex Smooth Leaf, Pope, and Rex and one African upland variety, Bar 7/8, were grown in the 1965–6 wet season at Kimberley Research Station, in the Ord River valley, Western Australia. The number of bolls, boll weight, lint percentage, seed cotton yield, lint yield, micronaire value, mature height, and morphological type were recorded for each plant.For all varieties the range of each attribute was wide; for example, for a typicalvariety, boll weight ranged from 3·0 to 7·8 g, lint percentage from 30·5 to 43·5%, micronaire value from 3·3 to 5·9 units, and mature height from 78 to 195 cm.The most variable varieties judged on coefficients of variation were those maintained at the station for the longest period without selection while the most recent accession was the least variable.Frequency distributions for all attributes in each population departed significantly from normality: the majority showed both significant skewness and kurtosis. Positive skewness shown for the yield parameters seed-cotton yield, lint yield, boll number and boll weight in all varieties suggested there was scope for improvement by selection. Negative skewness for lint percentage was found in three varieties, suggesting previous intense selection for this trait. The coefficient of variation of lint percentage with one variety (Deltapine Smooth Leaf) was considerably less than that recorded 30 years earlier for its predecessor D x PL 11 A.Covariance adjustments to seed cotton yield of individual plants, based on various hypotheses of the relationship between a plant's yield and that of its neighbours failed to give reductions of consequence in the variability of yield. It was concluded that inter-plant influences were far more complex than the models assumed.
The availability of calcium in three legumes of grassland
Authors: Armstrong R. H. , Thomas Brynmor 
Published: March 2009

1. The availability of the calcium in three grassland species, all legumes, has been investigated, with the rat as experimental animal.2. Two procedures involving determination of the calcium balance, (a) by analysis of feed, faeces and urine, and (b) by a slaughter technique, were used.3. The foregoing methods gave results, for any one species, which were without significant difference. It is considered that the slaughter technique would be the less laborious when any large number of determinations has to be made.4. The calcium in both lucerne and late-flowering red clover was available to a significantly greater degree than that in wild white clover. In all three species calcium availability was high.5. The possible significance of the high faecal calcium found in rats receiving wild white clover has been discussed.6. It was concluded that the extension of availability studies to a wider range of grassland species and of their ash-components would be desirable.
Physiology of seed yield in field beans (Vicia faba L.): II. Dry-matter production
Authors: Ishag Hassan M. 
Published: March 2009

SummaryDry weight per unit area was related to plant density differences and leaf area duration (LAD) up to pod-setting (late June). Total dry weight and seed dry weight at maturity were not related to total LAD or LAD after pod setting. Seed yield at a node was closely correlated with leaf area at the same node (r = 0·67 to 0·94).Differences in net assimilation rate (NAR) between varieties were not significant. A substantial rise in NAR in July-early August was attributed to additional photosynthesis by pods.
The effect of body-weight loss on the composition of Brahman cross and Africander cross steers
Authors: Seebeck R. M. 
Published: March 2009

SummaryComparative slaughter was used to assess the effects of body-weight loss on Brahman cross (BX) and Africander cross (AX) steers of the F3 generation with respect to the empty body weight, the hot carcass weight and various offal components. Animals were slaughtered at design weights of 325, 341, 358, 374 and 390 kg, some while during positive body-weight growth (Group A) and others during weight loss from 390 kg at a rate of 0·5 kg per day (Group B).AX animals had less empty body weight (B. B. W.) and dressed carcass weight (H. C. W.) at the same fasted body weight. Weight loss also reduced the amount of E. B. W. at the same fasted body weight but the effect on H. C. E. was not significant.The breeds were very similar with respect to the various components of the offal, except that the AX had heavier heads. The weight loss treatment increased the proportion of the head, tail and feet, because these comparatively bony structures lost relatively little during the weight loss period. The heart was also relatively increased by the weight loss treatment. The liver, gall bladder, kidneys, total gut tissue, spleen and thymus were reduced relative to E. B. W. in Group B animals. The liver showed its most rapid weight loss in the early period of body-weight loss, being the only organ to show any variation in its rate of change during body-weight loss.Body-weight loss caused changes in the distribution of the gut tissue, with a relative loss in the rumen-reticulum and a relative gain in the hind gut.
The effect of method and rate of application of common salt and muriate of potash on sugar beet
Authors: Holmes J. C. , Lang R. W. , Hunter E. A. 
Published: March 2009

SummaryTwelve experiments in the East of Scotland tested a hypothesis that the smaller yield responses to salt in Scotland than in England shown by previous work was due to the adverse effects of soluble salt concentration brought about by ridging, and also to test a wider range of salt and potash than used previously. All combinations of three rates of salt (0, 315, 630 kg/ha) and three rates of muriate of potash (0, 315, 630 kg/ha) were applied in four ways: (1) ploughed down in winter, (2) on the furrow in February, (3) in the seed bed and (4) half as (1) and half as (3). Plant emergence was decreased by salt and potash in only three experiments and then only when the larger amounts of both fertilizers together, along with nitrogen and superphosphate, were applied in the seed bed prior to ridging. Both experiments were in a year when the weather was dry while the plants emerged. Yield of sugar was greatest with the February application on the furrow and smallest with the ploughing down method. At equal weights, salt and muriate of potash had similar effects on sugar yield. Equations derived from the response surface gave the most profitable dressing as 377 kg/ha of salt plus 127 kg/ha of K2O which gave a £4.90 greater margin per hectare over costs than the best potassium application without salt.
Response of dwarf wheat (Triticum aestivutm L.) to graded doses of P and K on soils of different available P status
Authors: Singh B. R. , Singh L. , Singh B. P. 
Published: March 2009

SummaryResponse of wheat to fertilizer-P on soils low and medium in available P increased with increasing doses up to 26 kg P/ha; responses were proportionately greater on medium-P soils. Application of 39 kg P/ha increased the response slightly on low-P but decreased it drastically on medium-P soils. The relatively small response on low-P soils may be due to fixation of fertilizer-P. The results indicate that the maximum response to fertilizer-P may be obtained only when P fixing capacity of the soil is satisfied so that sufficient P for the crop remains in the soil solution. The results of this investigation suggest that fertilizer should be applied on the basis of soil test data of individual fields instead of following regional recommendations.
Interpopulational and intervarietal F1 hybrids in Lolium perenne: performance in field sward conditions
Authors: Foster C. A. 
Published: March 2009

SummaryFifteen intervarietal F1hybrids and their parents were evaluated in two field sward trials, representing three levels of management intensity each maintained over a 2-year harvest period. The trials were sown in different years and at different sites. Several hybrids exhibited significant levels of heterosis for total annual dry-matter yield – up to 5–5 % mid-parent and up to 3–6 % higher-parent heterosis. Within individual trials mid-parent heterosis up to 8% was found, while at particular harvests over 25% heterosis was not uncommon. Comparisons made of performance in swards, simulated swards and spaced-plant conditions showed that genetic differences found maximum expression in non-competitive conditions. This was greatly reduced in simulated swards and further suppressed in sown swards in the field. Expression of heterosis was highly specific to the conditions in which it was tested, although the two hybrids most heterotic as spaced plants were also significantly heterotic in field swards.
Copper levels in diets for growing pigs
Authors: Braude R. , Ryder K. 
Published: March 2009

SummaryResults of a co-ordinated trial carried out at twenty-one centres indicated that the performance of growing pigs (20–90 kg) can be improved by supplementation of their diet with copper sulphate.Three levels of copper supplementation were tested, 150, 200 and 250 mg Cu/kg diet. Though significant improvements were recorded on all three levels, the best performance and the highest increase in profitability were obtained with 250 mg Cu/kg diet. With increasing dietary intake of copper, the copper content of the pigs' livers increased markedly.The melting-point of subcutaneous fat was lower in carcasses of pigs that were given supplementary copper sulphate in their diet.
The expression of heterosis for yield in restored F1hybrid wheats and its interactions with seed rate and seed size
Authors: Sage G. C. M. 
Published: March 2009

SummarySeed of nine F1hybrid wheat genotypes was produced by wind pollination. In one trial, grown at two seed rates, the extent of heterosis for yield and two yield components was small and was not affected by seed rate. In an adjacent trial the extent of heterosis in three hybrids was found to be affected by seed size.
Fertility studies in relation to soil type
Authors: Calder F. W. , Macleod L. B. 
Published: March 2009

SummaryThree soil types – Pugwash sandy clay loam, Woodburn gravelly loam and Kirkhill silt loam – were compared by response to fertility treatments over two cycles of a 4-year rotation of 1 -year oats (AvenasativaL.) and 3 years of a grass-legume mixture for hay production. A rotation was started each year on a new section of the experimental site during the first rotation so that all crops were being grown in any one year. Treatments were: N; 0, 56, 112 kg/ha for the first rotation, 0, 168 and 336 kg/ha for the second rotation; P2O5; 0, 84, 168 kg/ha, first rotation, 0, 252 and 504 kg/ha, second rotation; K2O; 0, 67, 134 kg/ha, first rotation, 0, 252 and 504 kg/ha, second rotation. Manure was applied at 0 and 22 t/ha. There was a significant difference in yield for the three soil types for first-, second- and third-year hay crops. Manure increased yield of all hay crops on all three soils, and oat yields on Woodburn and Kirkhill soils. There were varying responses to rates of application of individual nutrients on different soil types. Percentage of species in the hay stands varied between soil types and between years. The differences found between soil types support the basic reason for classifying and mapping soils.