bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic and phenotypic aspects of doe productivity in four breeds of rabbits
Authors: Khalil M. H. , Afifi E. A. , Emara M. E. , Owen J. B. 
Published: March 2009

SummaryData on 841 purebred Bauscat, White Flander, Giza White and Baladi Red litters provided estimates of genetic, phenotypic and environmental parameters for gestation length, litter size at birth and at weaning, mortality and sex ratio at weaning. A total of 170 daughters (paternal half-sisters) of 76 sires were available for the analysis. No important differences were detected among breeds for litter traits studied except litter size at weaning (P< 0·001). Year of kindling affected (P< 0·001) gestation length, litter size at birth and mortality percentage. No clear patterns of the effect of parity and month of kindling on litter traits were observed. The sire of the doe and doe within sire affected most of the traits studied. Estimates of heritability indicated that the sire's genetic contribution to litter traits are much higher during the pre-natal period than for the suckling period. Estimates of repeatability for litter traits studied were relatively low. Genetic and phenotypic correlations between gestation length and other litter traits were relatively low. Litter size traits were positively correlated both genetically and phenotypically. Estimates of genetic and phenotypic correlation between litter size traits and preweaning mortality were generally negative. Phenotypic and environmental correlations were generally very similar in size and sign. Predicted direct selection was shown to give greater improvement in litter size at birth than indirect selection through litter size at weaning.
Use of soluble glass rumen boluses to provide a supplement of copper for suckled calves
Authors: Givens D. I. , Zervas G. , Simpson V. R. , Telfer S. B. 
Published: March 2009

SummaryAn experiment was carried out on a site where the copper content of herbage was relatively low (4·7–6·2 mg/kg d.m.) to examine the value of copper contained in soluble glass rumen boluses as a means of providing supplementary copper to calves.Forty-five spring-born suckled calves (mean live weight 91 kg) were divided into three groups on the basis of body weight. Animals in group GB were given two boluses initially, those in group CI each received copper injections at approximately monthly intervals and those in group C remained as controls throughout. Group C calves became progressively hypocupraemic (minimum mean plasma copper 8·5 μmol/1) compared with those in groups GB and CI which showed an increase in plasma copper concentration. In addition measurements of plasma caeruloplasmin activity, blood haemoglobin concentration and erythrocyte superoxide dismutase activity all showed significant increases due to treatment. No response in live-weight gain was observed but overall live-weight gain was approximately 1·05 kg/day. Although the initial response in plasma copper was quicker with copper injections, measurements of erythrocyte superoxide dismutase activity and haemoglobin showed advantages of glass boluses not shared by copper injections. This possibly resulted from the slow release nature of copper in the glass. Under the conditions of the experiment where herbage molybdenum values were relatively low (1·2–1·9 mg/kg d.m.), copper contained in soluble glass boluses appeared to prevent hypocupraemia in calves as effectively as regular copper injections.
Comparative influence of soil and management on barley yield in the Vale of Whitehorse, England
Authors: Ogunkunle A. O. , Beckett P. H. T. 
Published: March 2009

SummaryThe reliability of the soil series as a basis for crop yield prediction was examined by comparing the influence of soil and management (inter-farmer differences) on the variance of barley grain yield. Yields of barley were measured from farmers' fields for 2 years and in undisturbed soil cores for 5 years. Fields on different soil series within farms and on the same soil series across farms were used. Linear stepwise regressions of yield on a number of soil properties were also examined to assess the relative influence of soil and management on the properties that were significant to yield.The results show that generally, soil classification has a strong influence on yield variance, but there is clear evidence that the influence of management, specifically the cumulative effect of P and K fertilizer applications, is considerable. Thus in an undisturbed core, for the first 3 years when N, P, K and Mg were applied, the influence of soil was stronger than that of management, but this was reversed in the 4th year when P and K were not applied. Similarly in the field, the influence of soil was stronger in the 1st year, but this was reversed in the 2nd year, although on different field-farm combinations. In all cases, the influence of neither soil nor management was significantly stronger than the other.The results of the regression studies also confirmed those of yield variance in that in general, neither soil nor management has exclusive control of the yield variance. The soil was significantly stronger than management in the control of only coarse sand content at 0–15 cm out of the four soil properties (including Mg and pH (0–15 cm) and K (15–30 cm)) which were significant to yield in the cores. On the other hand, management was significantly stronger than soil in the control of only available P at O–15 cm out of the three soil properties (including Cu and Mg both at 0–15 cm) that were significant to field yield.It is concluded that for soil classification to be a reliable basis for yield prediction and/or agrotechnology transfer, the effect of management must be emphasized.
The effects of optimum heading date and its stability on yield and consistency of performance of barley and durum wheat in dry areas
Authors: Hadjichristodoulou A. 
Published: March 2009

SummaryData from several trials with large numbers of barley and durum wheat varieties conducted mainly under dryland conditions in a Mediterranean climate were used to study the effects of heading date and its stability on consistency of performance.Heading date was expressed in relation to one or more control varieties, because of the significant genotype × environment interactions. Data from trials during 1969–85 were used to determine optimum heading date in order to aid selection for consistently high-yielding varieties. For rainfed barley in Cyprus this optimum range was between 2 days after and 5–8 days before heading of Kantara barley and for rainfed wheat 1 day after to 4 days before heading of Karpasia durum wheat. It is suggested that by selecting at one environment single plants from segregating populations or lines from nurseries and yield trials, having heading date within the optimum range, the chances of selecting consistently high-yielding lines are increased.The genotype and environment significantly affected heading date. Stability of heading date was genetically controlled. Early varieties tended to be more variable than late varieties of both barley and durum wheat. Lines with the lowest values for variance of heading date gave low yields under variable conditions because they were very late. The consistently high-yielding lines of barley and durum wheat had variance of log transformed heading (s2log2) 0·025–0·050.In durum wheat, lines with the lowest variance were later in heading date than the optimum for Cyprus environments. The absolute values of variance of heading date of varieties varied with year, but significant positive correlations were obtained between years (r = 0·84 for durum wheat and r = 0·55 for barley, P < 0·01).Barley, which is considered a safer crop for the driest parts of the Mediterranean countries, heads a few days earlier than durum wheat but its better performance may be attributed also to its ability to grow faster than wheat in the winter months.
Blossom-end rot of watermelon in the southern region of Oman (Dhofar)
Authors: Hammouda A. M. 
Published: March 2009

SummaryBlossom-end rot, a non-parasitic disease, was found to occur widely on some oblong varieties of watermelon, causing much damage in the southern region of Oman (Dhofar). Fruit contact with soil surface seems to be the major agent of blossom-end rot of watermelon, especially in the early stage. Incidence of watermelon blossom-end rot was apparently reduced by mulch using a mixture of dried grasses or coconut leaves.
Physiological reasons for heterosis in growth ofBos indicus×Bos taurus
Authors: Frisch J. E. 
Published: March 2009

SummaryBy comparing growth rates of Brahman (B), Hereford × Shorthorn (HS), their reciprocal F1, hybrid (F1BX), their Fnhybrid (FnBX) and an F1Charolais × Brahman hybrid (FlCH x B) in environments that differed in their levels of stresses that affected growth, it was shown that heterosis for growth realized in any environment arose because of heterosis in its underlying determinants, namely growth potential and resistance to environmental stresses. Growth potential of the F1BX was similar to that of the better parent (HS) whilst resistance to environmental stresses was similar to or approached that of the more resistant parent (B). This combination of high growth potential and high resistance to environmental stresses enabled the F1BX to outgain both parents at all levels of environmental stress above zero. However, some or all of the heterosis in both growth potential and resistance to environmental stresses was lost in the FnBX. Thus, although previous selection for increased live-weight gain should have favoured the FnBX, they realized lower live-weight gains than the FlBX in all environments and lower live-weight gains than the parental breeds in all but intermediate environments.Because the breeds differed in both determinants of growth, the magnitude of estimates of heterosis for realized growth was dependent on the environment in which it was measured. A figure depicting this interaction was constructed.Comparative estimates were also made of the rate of approach to sexual maturity of bulls of each breed. The F1BX had similar values to the better parent (HS) for both scrotal circumference and plasma testosterone concentrations. However, the FnBX had values that were intermediate to those of the parental breeds.Generally, gains of the -F, CH × B exceeded those of all other breeds in all environments but their rate of approach to sexual maturity was slower than that of the F1BX.
The effect of increased energy demand through walking exercise on intake and ruminal characteristics of sheep fed a roughage diet
Authors: Henning P. H. 
Published: March 2009

SummarySheep were exercised on a treadmill to study the effect of increased energy demand on roughage intake and ruminal characteristics.The experiment consisted of a pre-exercise period during which exercise sheep walked for 30 min/day at 2 km/h against a gradient of 0° followed by a full exercise period during which they walked a total of 9 km/day at 3 km/h against a 10°gradient during six daily sessions of 30 min each. Control sheep received no exercise but were treated similarly to exercise sheep in all other respects.The mean values obtained during the pre-exercise period for the exercise and control groups and during the full exercise period for the exercise and control groups respectively were 1347, 1125; 1177 and 1114 g/day for organic matter (OM) intake; 956, 921; 803 and 848 g for rumen OM contents; 11·8, 13·6; 12·2 and 12·3 h for rumen retention time of water; 17·5, 20·2; 16·8 and 17·6 h for rumen retention time of fermentable OM; 27·3, 28·2; 26·4 and 26·7 h for rumen retention time of unfermentable OM and 46·9, 48·1, 44·4 and 45·9 kg for empty body weight. Only the decline in OM intake from pre-exercise to full exercise period differed significantly between exercise and control groups.It is concluded from these results that an increase in the difference between energy demand and supply per se is not responsible for the apparent increase in the upper limit to OM accumulation in the rumen and concomitant increase in roughage intake observed during other situations of increased energy output such as lactation and severe cold.
Effects of harvesting programme and sowing date on the forage yield, digestibility, nitrogen concentration, tillers and crop fractions of barley in Cyprus
Authors: Droushiotis D. N. , Wilman D. 
Published: March 2009

SummaryAll combinations of four harvesting treatments and two sowing dates were comparedin each of 3 years in field experiments near Nicosia. In two of the years, different levels of applied nitrogen were compared. The harvesting treatments were: (1) a milk-stage cut,(2) a boot-stage cut and a regrowth cut, (3) a grazing-stage cut and a regrowth cut, and(4) three grazing-stage cuts and a regrowth cut. The sowing dates were (1) normal (12 November) and (2) early (15 October), with sufficient irrigation to ensure establishment. There was almost no response to applied nitrogen, evidently because of high reserves of available nitrogen in the soil. Early sowing reduced by 20 days the time taken to reach the stage at which the first node appeared, but increased, by 36 days, the length of time between the first node and the milk stage. Early sowing increased yield when the firstcut was at the grazing stage, but reduced yield when the first cut was at the boot or milk stage. At the grazing stage, the proportion of green leaf blade and the concentrations of nitrogen and nitrate-N were relatively high (means 74, 4·0 and 0·13% respectively) and digestibility was moderate (mean D-value 61). By the boot stage, green leaf, nitrogen and nitrate-N, but not digestibility, had declined (means 21, 1·8, 0·02 and 63 respectively). By the milk stage, green leaf, nitrogen and digestibility, but not nitrate-N, had declined further (means 3, 1·5, 48 and 0·05 respectively). Fully dead leaf blades were 28 units less digestible and 3·2 percentage units lower in nitrogen concentration than emerging leaves. Half dead leaf blades were higher in nitrate-N than fully expanded, fully green blades. 'Stem’ declined greatly in nitrogen concentration, but relatively little in digestibility, between the grazing and the boot stage.Crops cut once or three times at a grazing stage recovered well, although theretended to be some reduction in the number of tillers compared with an undefoliated crop.
An analysis of primordium initiation in Avalon winter wheat crops with different sowing dates and at nine sites in England and Scotland
Authors: Kirby E. J. M. , Porter J. R. , Day W. , Adam Jill S. , Appleyard Margaret , Ayling Sarah , Baker C. K. , Belford R. K. , Biscoe P. V. , Chapman Anne , Fuller M. P. , Hampson Janice , Hay R. K. M. , Matthews S. , Thompson W. J. , Weir A. H. , Willington V. B. Anne , Wood D. W. 
Published: March 2009

SummaryThe initiation of leaf and spikelet primordia was studied at sites ranging in latitude from Newton Abbot (50·6°N) to Aberdeen (57·2°N) in crops sown in the middle of September, October and November 1983. The rate of primordium initiation tended to decrease from south to north but there were also marked differences between quite close sites.The rate of leaf initiation increased with temperature but photoperiod had little effect; the rate of spikelet initiation was affected both by temperature and by photoperiod. There were differences in the total number of leaves initiated which were only partlyexplained by differences in vernalization.Expressing leaf and spikelet initiation rates in terms of thermal and photo-thermal time respectively showed a constant rate of leaf initiation and a constant and more rapid rate of spikelet initiation.
Effects of infrequent drinking on the nitrogen metabolism of Bedouin goats maintained on different diets
Authors: Brosh A. , Shkolnik A. , Choshniak I. 
Published: March 2009

summaryThe effect of infrequent drinking on nitrogen metabolism was studied in Bedouin goats, a breed herded in the extreme deserts of the Middle East. The goats were given water either daily or only once every 4 days, while being maintained on roughages of different quality: lucerne hay (19% protein), Rhodes grass (10% protein) or wheat straw (3·7%). On lucerne hay and Rhodes grass the goats kept their body mass constant, whether given water daily or only once every 4 days. When on wheat straw the body mass was maintained constant only when given water once every 4 days. Infrequent drinking was found to hamper considerably the food intake of the goats when fed on high quality roughage. When on the wheat straw, the nitrogen intake of the goats (only 12% of that recorded when fed lucerne hay and given water daily) was, however, not affected by the drinking regime. Infrequent drinking improved nitrogen digestibility on all the diets, but more so on those of low quality than on the lucerne hay.When tested on the low quality feeds, urea excretion was low and urea retention and recycling were maintained at high rates. Infrequent drinking had no adverse effect on these capacities.
Dry-matter intake of Hereford and first-cross cows measured by controlled release of chromic oxide on three pasture systems
Authors: Barlow R. , Ellis K. J. , Williamson P. J. , Costigan P. , Stephenson P. D. , Rose G. , Mears P. T. 
Published: March 2009

SummaryFaecal output of 287 beef cows consisting of Hereford (H × H), Simmental × Hereford (S × H), Friesian × Hereford (F × H) and Brahman × Hereford (B × H) breeding was estimated using controlled release of chromic oxide (Cr2O3). All cows were from 6 to 10 years of age and had grazed on one of three pasture systems in the subtropics of New South Wales since they were 7–8 months of age. These pastures were designated as being of high, medium and low nutritive value. Faecal organic matter output (FOMO) was estimated in each of four periods (early lactation, mid lactation, late lactation, and non-lactating) during one annual production cycle.Herbage mass exceeded 2 t/ha on all pasture systems, but estimates of organic-matter digestibility, nitrogen content and pasture composition indicated large differences in pasture quality (high > medium > low). Live weight of cows averaged 604, 488 and 393 kg live weight on the high, medium and low pastures, respectively. There were significant differences in live weight between genotypes on the medium (B × H > F × H and H × H) and low (S × H ≡ F × H ≡ B × H > H × H) pastures but not on the high pasture).FOMO and dry-matter intake (DMI) differed significantly between genotypes among lactating cows on all pasture systems. Rankings on high pastures were reasonably consistent in all periods: S × H ≡ F × H ≥ B × H ≥ H × H, as were those on low pastures, B × H ≥ S × H ≡ F × H ≥ H × H. Differences on medium pastures were significant only during mid-lactation when B × H ≡ S × H ≡ F × H > H × H. Significant differences between genotypes were observed among non-lactating cows on high pastures only, where H × H ≡ S × H ≡ F × H > B × H. Lactating females had significantly higher FOMO and DMI than non-lactating females when compared across genotypes during early lactation on all pastures.
Growth of sugar-beet crops including the influence of synthetic plant growth regulators
Authors: Green C. F. , Vaidyanathan L. V. , Ivins J. D. 
Published: March 2009

J. agric. Sci., Camb. (1986), 107, 285–297The authors regret that Fig. 9 relating sucrose weight to total dry weight contained a few misplotted measurements. The sixth group of bivariate observations (five data points) were plotted a factor of 10 g/plant too light in the y-direction (sucrose weight). This error was not present in curve fitting, thus the fitted relationship (Fig. 9; Table 2) is correct fitted relationships on Figs 5 and 9 and thus also remain unchanged. Figure 9 should be presented as
Evaluation of polyethylene glycol test of measuring cell membrane stability as a drought tolerance test in wheat
Authors: Premachandra G. S. , Shimada T. 
Published: March 2009

SummaryEffectiveness of the polyethylene glycol (PEG) test for measuring cell membrane stability (CMS) to select drought-tolerant genotypes in wheat was investigated. PEG test was compared with two other tests. Genetic variability of CMS was also investigated.Drought was induced artificially in pot-grown plants and in excised leaves, and percentage injury in leaf tissues by drought stress as measured by CMS was compared with that by PEG test. Percentage injury in leaf tissues of pot-grown plants was not correlated significantly with that by PEG test. However, percentage injury in excised leaves was well correlated with that in PEG test. The results suggest that the PEG test has merit in measuring drought tolerance in wheat. Frequency distribution of CMS in winter wheat lines was closely related to the characteristic pattern of quantitative inheritance and therefore CMS of wheat seems to be controlled by polygene action.
Inheritance of three agronomic characters in Lycopersicon interspecific crosses
Authors: Yassin T. E. 
Published: March 2009

SummaryCrosses between two cultivars of tomato (Lycopersicon esculentum Mill.), and two accessions of the wild species L. pimpinellifolium (Jusl.) Mill, were made and F1, F2 and backcross generations were developed and studied. Significant differences in number of fruits per plant, yield per plant and fruit weight were found between means of the different generations. Variation in number of fruits per plant and yield was also found between plants within generations. Number of fruits per plant was a highly heritable character (average h2 = 73·6%) and closely correlated with yield per plant, indicating that it may be a suitable selection criterion for yield improvement in tomato crosses.
Water requirements and metabolism in Egyptian Barki and Rahmani sheep and Baladi goats during spring, summer and winter seasons
Authors: El-Nouty F. D. , Hassan G. A. , Taher T. H. , Samak M. A. , Abo-Elezz Zahraa , Salem M. H. 
Published: March 2009

SummaryWater requirements and metabolism were studied in eight each of Barki and Rahmani sheep and eight Baladi goats. The animals were individually housed in the shade in semi-open pens that were located in a non-desert area. The experiments were carried out during spring, summer and winter seasons, and each experiment lasted for 3 weeks during each season. After a preliminary period of 1 week, an 8-day period was then followed during which body weight, daily feed intake and daily drinking water were recorded. Rectal temperature and respiration rate were also recorded in the early morning and late afternoon. Four animals from each group were then weighed and injected intravenously with tritiated water, TOH (001 mCi/kg body weight) and blood samples were collected during a 4-day period to estimate total body water (TBW) and water turnover rate (WTR).In all seasons studied, the Rahmani sheep had higher TOH disappearance rate (^-values) and WTR and consequently shorter biological half-time (1½) than the Barki. Moreover, the Barki sheep showed less thermal discomfort than the Rahmani particularly during the summer. Although the Rahmani sheep ingested more water than the Barki sheep during the summer, the Rahmani sheep had a lower percentage of TBW and their calculated water loss revealed that they were in negative water balance during this season. Accordingly, the Barki sheep seem to perform better than the Rahmani in newlyreclaimed desert areas. Baladi goats appear to be more adapted to unfavourable environmental conditions than sheep. This is based upon the findings that they had lower k-values, lower WTR, longer tiand higher TBW, than the two breeds of sheep.