bluuebunny/crossref_metadata_2025_split huggingface dataset:
Counting blood cells of chickens
Authors: Chubb L. G. , Rowell J. G. 
Published: March 2009

1. Six methods of diluting chicken's blood prior to counting erythrocytes and leucocytes in haemacytometers have been studied. No difficulty is found in recognizing erythrocytes. The most satisfactory method of counting leucocytes was the method described by Natt & Herrick (1952) in which the diluent contains methyl violet. Formulae are given which enable standard errors of estimates to be calculated.2. Three methods of staining blood smears for the differentiation of the various leucocytes have been studied. The method using Leishman's stain appeared to result in good differentiation and was simple to use. However, an experiment to study sampling errors has shown that there may be considerable differences between observers in the percentages of lymphocytes and heterophils when the latter are high, showing that the estimates of these quantities may be biassed. These differences may have been caused by a tendency for heterophils to concentrate to the edges of the smears and for the observers to select different fields for their counts.3. Although blood counts varied only slightly during the day, there were considerable differences from day to day. The average erythrocyte count for ten chickens fluctuated between about 2·9 and 3·5 millions per mm.3 during the first 3 weeks after hatching and was more steady for the next 4 weeks at about 2·9 millions per mm.3. The average leucocyte count rose from about 10,000 to 35,000 per mm.3 during the first 7 weeks of life, the rate of increase being greatest when the chickens were youngest; the rise was mainly due to a rise in the number of lymphocytes.4. There were also considerable differences in blood counts between chickens even though environmental and genetic conditions were standardized as far as possible.
The effect of copper therapy on the growth rate and blood composition of young growing cattle
Authors: Givens D. I. , Hopkins J. R. , Brown Marjorie E. , Walsh W. A. 
Published: March 2009

SUMMARYA total of 187 animals (mainly Friesian dairy heifers) on nine farms in Wharfedale, Nidderdale, Calderdale and the Vale of York were weighed, condition scored and blood sampled on three occasions during the grazing season 1977. On each site, half of the animals each received two injections of a Cu preparation (200 mg Cu total), one in May and one in July. Herbage samples were taken in May, July and September.Despite the fact that many animals started the experiment with low blood total Cu concentrations, growth rates during the experimental period were all satisfactory (lowest mean value 0·70 kg/day) with a significant increase due to treatment being observed on only one site. The Cu treatment, however, had a significant effect on blood and plasma total Cu values with the treatment either increasing the level to normal in animals which had started with low values, or maintaining the value in animals starting with near normal concentrations. On certain sites, animals in the untreated group ended the experiment with very low blood and plasma total Cu values (0·02–0·03 mg/100 ml). To prevent the possibility of a Co deficiency on some sites interfering with the experiment, all animals received a Co bullet initially. Despite these, concentrations of vitamin B12 in serum samples taken during and at the end of the experiment were low by present interpretation. This suggests either that Co bullets were an ineffective treatment or that the present interpretation of serum vitamin B12 concentration in bovines is incorrect.The calculated concentrations of available Cu estimated from herbage analysis indicated that on most sites the value was below the optimum for the growing cattle under study. The results of the experiment suggest that even when blood Cu values and herbage available Cu values are low a growth response to Cu injections may not occur over the course of a grazing season.
The effects of selection for number of ears on the yield and water economy of winter wheat
Authors: Innes P. , Blackwell R. D. , Austin R. B. , Ford Margaret A. 
Published: March 2009

SUMMARYSelections for high (H) and low (L) number of ears were made from crosses between three pairs of winter wheat varieties. By the F5 generation there were consistent, heritable differences between H and L selections in each cross. In an irrigated trial the H lines outyielded the L lines even in one experiment where compensatory increases occurred in the weight of grain per ear of the L lines. Drought for the 5 weeks before an thesis reduced the final number of ears of the H lines by 14% but did not affect the final number of ears of the L lines. This reduction in the final number of ears of H lines resulted in them being outyielded by L lines by 8%. Drought from anthesis to maturity did not significantly reduce grain yields of either H or L lines below their values under full irrigation.When fully irrigated, the evapotranspiration of H and L lines from 1 April until maturity was approximately 360 mm. The drought before anthesis reduced water use to about 320 mm, there being no difference between selections in total water use by the crops during this period. However, the L lines extracted significantly more water from the soil below a depth of 0.9 m during this drought than the H lines, and this appeared to make the L lines less susceptible to drought at this stage. Water use by the crop during the late drought could not be reliably estimated because by this time water was being extracted from below the level of the neutron probe access tubes.It is concluded that in an environment where a pre-anthesis drought is unlikely to occur, varieties with high ear-bearing capacity may give the best yields. Selection for types showing a limited tillering capacity may prove to be an effective compromise in regions with erratic rainfall where pre-anthesis droughts can occur.
Cultivation systems for spring barley with special reference to direct drilling (1971–1974)
Authors: Hodgson D. R. , Proud J. R. , Browne S. 
Published: March 2009

SUMMARYFive cultivation systems for spring-sown barley were tested on a clay to sandy-clay loam for 4 years and their cumulative effects on soil and crop measured. Four primary cultivations in the autumn, shallow (7·5 cm), medium (15 cm) and deep (23 cm) tine cultivation and mouldboard ploughing (23 cm deep) followed in spring by secondary cultivations and sowing, were compared with direct drilling seed into uncultivated soil after controlling weeds with herbicides. At the same rates of seed and fertilizer for all systems, direct drilling and shallow cultivation yielded significantly less grain than deeper tillage in the second year only; over 4 years the differences in mean yield were small and non-significant. In terms of crop output per unit of implement net energy (estimated) direct drilling was eight times more efficient than ploughing.Direct drilling and shallow cultivation caused concentration gradients of ‘available’ phosphorus and potassium to form in the top soil. Soil strength and to a lesser extent bulk density were greater without than with cultivation but these changes had only a relatively small effect on root distribution in the profile. In untilled soil the proportion of the root system was less in the surface 2·5–12·5 cm and greater in the 12·5–32·5 cm horizon than in shallow or deep tilled soil.Mean nitrogen uptake by the crop in the third and fourth seasons was least in direct - drilled barley probably due to lower rates of mineralization of soil nitrogen in compacted than tilled soil. It was deduced that for spring barley the ‘yield plateau’ was the same for each system but that optimal rates of nitrogen would be higher for crops in untilled than tilled soils.
Inheritance of resistance to cow-pea weevil (Callosobruchus maculatus, Fabr.)
Authors: Fatunla T. , Badaru K. 
Published: March 2009

SUMMARYFour bruchid-susceptible and four bruchid-resistant cow-pea cultivars were crossed to produce 16 F1s and their reciprocals. From each cross, six generations, P1, P2, F1, F2, BC1, BC2, were obtained. Each cross was fitted to the additive-dominance model. Estimates of additive and dominance variances were obtained from the half and full sib analyses of the F1s and their reciprocals respectively. It was demonstrated that resistance to cow-pea weevils has additive, dominance and maternal components.
The relationship between post-parturient fatty liver and blood composition in dairy cows
Authors: Reid I. M. , Rowlands G. J. , Dew A. M. , Collins R. A. , Roberts C. J. , Manston R. 
Published: March 2009

SUMMARYThe blood composition of 45 cows with more than 20% fat in the liver (moderate fatty liver) was compared with that of 83 cows with less than 20% fat in the liver (mild fatty liver). The cows were sampled at 1 week after calving and were from three Friesian and one Guernsey herds. Blood concentrations of non-esterified fatty acids, bilirubin and aspartate amino-transferase were significantly elevated in cows with more than 20% in the liver whereas concentrations of glucose, cholesterol, albumin and magnesium were all significantly reduced. Blood samples from cows in two of the herds were analysed for ammonia, insulin and D(-)3-hydroxybutyrate. Cows with moderate fatty liver in these two herds had significantly lower insulin concentrations and higher D(-)3-hydroxybutyrate concentrations than those with mild fatty liver. Using an equation based on blood concentrations of non-esterified fatty acids, glucose and aspartate aminotransferase it was possible to assign correctly three out of four cows to either the mild or moderate fatty liver groups.
The relationship between total seasonal rainfall and yield of maize in the Kenya highlands
Authors: Glover J. 
Published: March 2009

A study of the climate within the maize-growing areas of the West Rift area of the Kenya Highlands showed that rainfall is the major meteorological variable.A further investigation showed that average yields of maize in subdistricts within the region are markedly affected by changes in seasonal rainfall and are apparently unaffected by large changes in acreage planted from year to year over a period of eleven years.
The significance of grading-up in the Ayrshire cattle population of Great Britain
Authors: Wiener G. 
Published: March 2009

The grading-up system, in the Ayrshire Cattle breed, whereby the descendants of non-pedigree cows enter the registered (Herd Book) population, is studied principally from three aspects: (1) its numerical importance in the population; (2) the breeding structure of herds practising grading-up, and (3) the possible genetic effect of grading-up on milk and fat yield.Cows at various stages of grading-up are noted in an Appendix to the Herd Book. The numerical importance of the grading-up system has varied with the rate of expansion of the breed as a whole—being greatest during the most rapid expansion—but, at all times, Appendix cows have had more registered female offspring than have pedigree cows. The volume of grading-up was regulated by the number of cows in Appendix B. Some 6% of the pedigree females registered in the last 30 years have Appendix A mothers and a further 5% or so owe their existence to grading-up during the last 30 years.On average, the proportion of herds registering bulls is not greatly different among the herds which grade-up and those which do not. Similarly, the ratio of males to pedigree females registered was about the same in both types of herd. None-theless, there appears to be considerable selection against Appendix animals in the ancestry of bulls compared with cows, and none of the large bullbreeding studs appear to pursue a grading-up policy. A greater proportion of Ayrshire herds were grading-up in Scotland than in England.Entry into Appendix B of the Herd Book is confined to cows reaching a qualifying yield. The daughters (A) of these B cows mated to unselected pedigree bulls were found to yield significantly more in their first lactation (36 gal. milk and 14 lb. butterfat) than contemporary pedigree Ayrshire heifers in the same Scottish milk recorded herds in 1955. Part, if not all, of this superiority is thought to be genetic.
The effect of dietary intake of calcium and phosphorus on the absorption and excretion of phosphorus in chimaera-derived sheep
Authors: Field A. C. , Kamphues J. , Woolliams J. A. 
Published: March 2009

SUMMARYThe effect of ratios of calcium to phosphorus in the diet (varying from 0·6 to 3·6) on the absorption and excretion of P was investigated with four sets of 9-month-old chimaera-derived triplets. A pelleted cereal-based diet supplemented to contain 1·5, 3·1 or 6·2 g P/kg D.M. and 3·4 or 5·4 g Ca/kg D.M. was used in a factorial design.The additional Ca in the diet reduced the efficiency of absorption of the P supplements in the diet by 0·18 ± 0·04.The efficiencies of absorption of total P were very similar within but markedly different between (P < 0·001) sets of triplets, the mean values being 0·62, 0·74, 0·82 and 0·84. The fractional absorption of inorganic P alone showed the same ranking and the mean values were 0·47, 0·67, 0·85 and 0·92. These differences between triplets support the view that the individual differences in P metabolism have a genetic basis. The mean absorbability of P in the basic diet (0·77) and in the P supplements (0·73) were similar.The pattern of excretion of absorbed P between the faecal and urinary route of excretion varied between the sets of triplets; as P intake increased, the additional absorbed P was excreted in faeces by one set, in urine by another and in faeces and urine by two sets. The relative importance of the faecal route was dependent upon the fractional absorption of P secreted into the gut.
Response of wheat cultivars to dates of sowing under dryland conditions
Authors: De R. , Saran G. , Turkhede B. B. , Lal R. B. , Singh R. K. , Giri G. 
Published: March 2009

SUMMARYField experiments made for 4 years between 1976–7 and 1979–80 in a semi-arid environment of north-west India showed that the productivity of dryland unirrigated wheat can be increased considerably by adjusting the date of sowing to conducive atmospheric temperatures. Sowing in the middle of November when daily mean temperatures ranged between 19 and 21 °C produced yields ranging between 2·6and 3·5t/ha (averaged over the 4 years) compared with 1·4–3·3 t/ha obtained from the crop sown by mid-October when the daily mean temperature ranged between 24 and 26 °C. The tall cultivar C 306, a derivative of winter x spring wheat cross, could withstand sowing at higher temperatures (mid-October) more than the spring wheats. High temperatures prevailing during the seedling stage of spring wheats shortened their vegetative growth and initiated early differentiation. Night temperatures above 13 °C coupled with day temperatures of 33–35 °C in the last fortnight of October adversely affected the tillering of spring wheats sown on 15 October and produced smaller spikes with few fertile spikelets.
Compensatory growth and yield of pigeon pea (Cajanus cajan) following pod removal at different stages of reproductive growth
Authors: Tayo T. O. 
Published: March 2009

SUMMARYAll the pods on pigeon-pea plants were removed after 1, 2 or 3 weeks of flowering in a pot experiment and in one field trial, in order to evaluate the compensatory ability of the crop under humid tropical conditions.Pod removal after 1 or 2 weeks of flowering led to an immediate significantly higher vegetative development and dry-matter accumulation compared with the control. Subsequent flowering led to greater pod production and pod yield than the control with seed yield increased by 21 and 50%, respectively, in the pot experiment while pod removal after 1 week of flowering increased seed yield by 15% in the field. The removal of pods after 3 weeks of flowering was detrimental to subsequent pod development and seed yield which was decreased by 56 and 34% in the pot and field experiments, respectively.It would seem that the loss of pods produced soon after flowering starts, before active pod filling begins, can be tolerated by pigeon peas, whereas the loss of fully elongated and actively filling pods would significantly reduce seed yield in the crop.
Endocrine relationships in the induction of oestrus and ovulation in the anoestrous ewe
Authors: Robinson T. J. 
Published: March 2009

1. A total of forty-two Suffolk cross-bred and 230 stud Romney Marsh ewes were used in four experiments in which pregnant mare serum gonadotrophin (p.m.s.) was used in various combinations with progesterone and oestrogen in attempts to induce fertile mating in anoestrus.2. Groups of six Suffolk cross-bred ewes were injected with 1000 i.u. p.m.s. after pretreatment, commencing 4 days earlier, with 75 mg. progesterone administered in one of four different ways. Six twice-daily injections in oil resulted in oestrus in five ewes in each of two groups treated. Single injections in oil solution, aqueous suspension, and benzyl alcohol emulsion resulted in oestrus in two, nil, and four ewes, respectively. All were served within 48 hr. of injection of p.m.s.3. Ovulation was observed in five of six crossbred ewes which received six twice-daily injections of progesterone in oil, without subsequent injection of p.m.s. Three were served.4. Divided injections of progesterone commencing 4 days before 750–1000 i.u. p.m.s. failed to induce a satisfactory oestrous response in Romney Marsh ewes. An increase to 7 days in the duration of progesterone stimulation resulted in oestrus in all of eighteen ewes treated.5. The injection of a benzyl alcohol emulsion containing 75 or 150 mg. progesterone, given as a single dose 4 or 7 days before 750 i.u. p.m.s., failed to induce a satisfactory oestrous response. Of seventy-two ewes treated, only seven were served.6. Lambing results were most unsatisfactory when progesterone-p.m.s. treatment was followed by artificial insemination. Of 144 Romneys inseminated, only twelve lambed. Successful pregnancy appeared unrelated to the type of treatment or the occurrence of oestrus.7. On the basis of the oestrous responses observed after the injection of a variety of combinations of oestrogen, progesterone, and p.m.s., and by reference to quantitative data on progesterone-oestrogen relationships in oestrous behaviour in the spayed ewe, it is concluded that the developing follicle of the Romney Marsh ewe produces an amount of oestrogen approximately equivalent, in its physiological activity, to a single injection in oil of about 20 μg. oestradiol benzoate.
The achievement of very high yields of potatoes in the U.K.
Authors: Evans S. A. , Neild J. R. A. 
Published: March 2009

SummaryCrops of potatoes grown on 0·2–0·3 ha in each of the years 1971–8 at Stockbridge House Experimental Horticulture Station achieved total tuber yields of 70–94 t/ha. Yield was determined by the period and rate of tuber growth. The observed period of growth varied from 96 to 132 days and the rate from 0·55 to 0·90 t/ha/day. Rate of growth had the greater influence on variability of yield between the years. The number of tubers produced per unit area had little influence on their total weight, but had marked effect on their size. Adequate water supply was essential for very high yields. Experiments indicated that current recommendations for potash fertilizer can be adequate but that nitrogen and phosphate fertilizer use may need to be enhanced for very high yields. For high yields, the number of seeds planted per hectare may need to be higher than normally recommended in order to avoid the production of large tubers unsuitable for the ware market.
Variation in the low temperature growth and frost tolerance of natural genotypes of Trifolium repens L. from Britain and Norway
Authors: Ollerenshaw J. H. , Haycock R. 
Published: March 2009

SummarySixty-two genotypes of Trifolium repens (white clover) collected from latitudes 52° to 68° N and five selected genotypes of the cultivar S.184 were screened for shoot growth at low temperature and short daylengths in a controlled environment cabinet and in the field, and subjected to cold hardiness treatments ranging from – 2·5 to – 14·0 °C.Considerable variation was discovered in several of the growth characteristics and in the frost tolerance of the genotypes. Genotypes exhibiting the highest rates of stolon extension were found in the more southerly latitudes. A high proportion of leaves produced during winter on the primary stolons of the selected cultivar plants subsequently died during the late spring at the upland field site, but several of the naturally occurring genotypes were able to retain more leaves per stolon in spring. Some genotypes appeared to maintain either short or long internodes throughout the spring in the field, whilst others produced relatively short internodes in early spring and long internodes later in the season, and vice versa. Only a small percentage of the genotypes possessed relatively long leaflets. A correlation was found between maximum leaflet length of the genotypes in early spring, and maximum leaflet length in late spring.No relationship was found between frost tolerance and the growth of plants at low temperature. Frost sensitive and tolerant genotypes were found throughout the latitudinal and altitudinal ranges studied. Exposure to prevailing winds and possibly snow cover at the site of origin appeared to be important factors associated with the frost tolerance of T. repens plants.
Changes in phosphorus metabolism of sheep in response to the increased demands for P associated with an intravenous infusion of calcium
Authors: Braithwaite G. D. 
Published: March 2009

SummaryThe effect on phosphorus and calcium metabolism of a high rate of Ca infused directly into the blood of 10-month-old sheep, already receiving an adequate Ca and P intake, has been studied by a combination of balance and radioisotope techniques. Ca retention was significantly increased during the infusion and most of the extra Ca was retained in bone. Urinary Ca excretion also showed a small but significant increase and the efficiency of Ca absorption a small but significant decrease. Because of the close association of Ca and P in bone, the increased skeletal retention of Ca resulted in an increased skeletal P retention and hence an increased demand for P. This increased P demand was met partly by a decrease in the rate of endogenous faecal loss of P and partly by an increase in the rate and efficiency of P absorption. Because the increase in P demand was relatively small, it was not possible to decide whether the endogenous faecal loss of P can be reduced in response to increased demands to the level found at zero P intake as suggested by the Agricultural Research Council (1980) or whether higher losses at normal P intakes are inevitable.
Changes in soil fertility status as influenced by continuous cropping and fertilizer application
Authors: Sharma K. N. , Singh Bijay , Rana D. S. , Kapur M. L. , Sodhi J. S. 
Published: March 2009

SummaryChanges in soil fertility status brought about by the application of P and K fertilizers and farmyard manure (FYM) to a fixed wheat-maize rotation for 10 years in a calcic ustochrept are reported. The treatments comprised three rates of P (0, 30 and 60 kg P2O5/ha), two rates of K (0 and 30 kg K2O/ha) and two rates of FYM (0 and 15 t/ha) applied to maize or wheat alone or to both the crops. Organic carbon and available P and K contents of the soil increased significantly with the addition of FYM. P application at 60 kg P2O5/ha nearly maintained the original level of available P even after 10 years of continuous cropping. However, a considerable and highly significant increase in available P was obtained with the combined application of P and FYM. Available K status of the soil remained more or less unaffected by K application. Organic carbon content, and available P and K contents were significantly higher in the plots that received fertilizers and manure for both the crops than in those where the application was to maize or wheat alone.