bluuebunny/crossref_metadata_2025_split huggingface dataset:
The growth rate of heifers in a dairy herd
Authors: Ridler B. , Broster W. H. , Foot A. S. 
Published: March 2009

Growth rates of Shorthorn and Friesian heifer calves from 0 to 6 months of age were studied from live-weight data collected over a 10-year period.Friesian calves were heavier than Shorthorn. Male calves were heavier than female. Calves born to the first pregnancy were smaller than those born to later ones. Gestation length was 5 days shorter for Friesian than for Shorthorn cows. It tended to be slightly shorter for female than for male calves. Non-foetal loss of weight at calving was greater with male than with female calves.High-level feeding before calving was associated with heavier calves but the effect was not statistically significant.Calf birth weight increased by 0·026 lb./lb. increase in post-calving live weight of the dam and by 0·564 lb./day extension of the gestation period.Growth rate accelerated from birth to 3–4 months of age and then declined slightly. Autumn-born calves grew faster in the first 90 days than springborn calves. Age of dam and level of feeding before calving had no effect on rate of growth of the calf.For both breeds there were significant negative correlations between birth weight and rate of gain in the first month after birth.
The grazing animal and sward productivity
Authors: Herriott J. B. D. , Wells D. A. 
Published: March 2009

1. The results of a trial designed to investigate the effects of sheep excreta on sward growth and yield are described.2. The quantities of plant nutrients excreted, and their distribution, by the grazing animal are discussed. An assessment is made of the value of excreta to pasture growth in the light of the results gained.3. Under Boghall conditions, the return of excreta had little affect on sward output, the main effect was for the pasture to become progressively more grass dominant. In general, weather and soil nutrient limitation had a greater effect on nitrogen yields from the swards than did excreta. Recovery of excreta nitrogen would appear to be influenced by rainfall and the age of the sward.4. On a soil inherently low in available potassium, it was found that this element and nitrogen both affected the pattern of herbage growth and composition when returned in excreta. Phosphorus return by the sheep was, however, of no observable value in either the levels of the element in the soil or in the herbage. It was found that rainfall and the botanical composition influenced the contents of mineral elements in the herbages.5. Balance studies suggest that sheep grazed in small paddocks need adequate pre-conditioning before being moved into a trial. Only by this means can return of excreta reflect consumption of herbage. The limitations of small-scale animal grazing experiments are discussed.
The nutritive value of grasses grown in Uganda when fed to zebu cattle II. The relation between crude fibre and nitrogen-free extract and other nutrients
Authors: Bredon R. M. , Harker K. W. , Marshall B. 
Published: March 2009

The correlation between chemical composition and nutritive value of grass fed to short-horn zebu steers in Uganda was investigated. The following regression equations were calculated from the experimental results and discussed in part I of this paper.Dig. coef. of C.P. = 100·89 log c.p. – 44·45;r = 0·9738, P < 0·001.(For use when fodders of wide range of proteins are compared.)Dig. coef. of c.p.= 5·14 c.p.;r – 0·9339, P < 0·001.(For quick calculation when only approximate figures are required.)Dig. coef. of c.p. = 9·588 + 4·284 c.p.;r = 0·9521, P < 0·001.To be used between 4·5 and 17% of crude protein.)% c.p. in grass eaten = 1·677 c.p.infaeces – 6·93; r = 0·958, P < 0·001.Dig. coef. of d.m. = 41·81 + 1·63 c.p.;r = 0·9362, P < 0·001.Dig. coef. of o.m.= 46·05 + 1·4152 c.p.;r = 0·8851, P < 0·001.The regression equations calculated from the experimental results in the present paper (part II) are as follows:Dig. coef. of d.m. = 150·88 – 1·179 (c.f. + n.f.e.);r = 0·9634, P < 0·001.Dig. coef. of d.m. = 120·03 – 1·778 c.f.;r = 0·721, P < 0·01.Dig. coef. of o.m. = 142·50 – 1·045 (c.f. + n.f.e.);r = 0·9320, P < 0·001.t.d.n.= 129·39 – 0·9419 (c.f. + n.f.e.);r = 0·9288, P < 0·001.t.d.n. = 7·76 + 0·8192 dig. coef. of d.m.;r = 0·9886, P < 0·001.s.e. = 0·9367 dig. coef. of d.m. – 20·15;r = 0·9832, P < 0·001.s.e. = 120·80 – 1·104 (c.f. + n.f.e.);r = 0·9468, P < 0·001.s.e. = 99·44 – 1·868 c.f.r = 0·7948, P < 0·01.
Bacteria of the ovine rumen II. The functional groups fermenting carbohydrates and lactate on a diet of lucerne (Medicago sativa) hay
Authors: Kistner A. , Gouws L. , Gilchrist F. M. C. 
Published: March 2009

1. The composition of the bacterial populations of the rumen of three sheep on lucerne hay was very similar with regard to both the levels of the functional groups which ferment cellulose, starch, glucose and xylose and to the morphological types of which they were composed. The lactate-utilizing bacteria showed more variation in numbers between individual animals.2. The rumen flora of lucerne hay fed sheep differed from that of sheep on teff hay not only in significantly higher counts of the carbohydratefermenting bacteria in the former group, but also in distinctive types of cellulolytic bacteria.3. The short- and long-term variations in number of cellulose digesters found earlier in a sheep on a practical diet of lucerne hay were not markedly reduced by feeding the same animal lucerne hay of constant composition.4. A correlation appeared to exist between the protein content of the lucerne hay and the level of the lactate-fermenting bacteria in the rumen.5. The changes in the viable counts of the bacteria capable of fermenting cellulose, starch, glucose and lactate during the first 8 hr. after feeding a ration of lucerne hay were small compared with thein vitrorate of multiplication of a pure strain of cellulolytic cocci isolated from a sheep on the same diet. This is regarded as further evidence in favour of the notion that the rumen contents, particularly of animals on high roughage diets, approximates to a continuous culture system.
Effect of Subclinical Helminthosis on nitrogen metobolism in beef cattle
Authors: Vercoe J. E. , Springell P. H. 
Published: March 2009

SUMMARYThe differential effect of subclinical helminthosis on digestion and nitrogen metabolism in 1-year-old Brahman x Hereford/Shorthorn cross and British (Hereford/Shorthorn cross) steers was investigated.When helminths were present, the British steers had lower digestibilities of dry matter and nitrogen, lower nitrogen balances, and higher dialysable faecal nitrogen, than had the Brahman cross steers. There were no breed differences in plasma gastrointestinal leakage (estimated by Cr labelling of plasma proteins), plasma content, total plasma protein, plasma protein half-life or plasma urea.When helminths were eliminated, plasma gastrointestinal leakage was reduced, and plasma content and total plasma protein were increased. These changes were relatively larger in the British steers. The Brahman crosses had lower plasma protein concentrations and higher plasma urea concentrations than the British steers. Plasma protein half-life was unaffected by parasites.The breed difference in the haematocrit was not affected by the presence or absence of helminths.
Variation in the time of parturition of Merino and Dorset Horn ewes
Authors: George J. M. 
Published: March 2009

SUMMARYIn a comparison involving 1467 births significantly more Dorset Horn than Merino ewes lambed during the period 08.00–18.00 h. The distribution of lambing during the day differed significantly between breeds. The daytime patterns averaged over breeds, and differences between breeds in patterns, did not change from year to year. At winter and spring lambings, 37% of Merino and 62% of Dorset Horn ewes lambed during the day (08.00–18.00 h) while during summer the corresponding percentages were 23 and 39.For both breeds, the percentages of primiparous and multiparous ewes lambing during the day period were approximately the same. For Dorset Horns, the proportions of single and multiple births occurring during the day were similar.
The effect on the reproductive performance of sows of dietary protein concentration and pattern of feeding in pregnancy
Authors: Pike I. H. , Boaz T. G. 
Published: March 2009

SUMMARYIn a factorial experiment the effect of two protein intakes and three patterns of feeding in the second pregnancy of 48 Large White x Wessex Saddleback sows was examined. The high protein (HP) diet (19·5% crude protein) contained 15% white fish meal. The low protein (LP) diet (10·5% crude protein) contained cereal protein only. Nutrient components of the diets differed in protein only. The pattern treatments involved allowances of 1·8 kg (L), 2·7 kg (C) and 3·6 kg (H) per day, the three pregnancy patterns being HL, C and LH with the changeovers made from the 49th to the 63rd day post coitum (p.c). Sows on the three pattern treatments received the same total amount of feed from 0–112 days p.c. and were treated alike at farrowing and during lactation.Fertility and parturition results were similar for all treatments, but the number of piglets alive after birth (when weighed) was least for LP sows on the HL pattern. At 3 weeks of age the size and weight of litters on HP sows were significantly greater than those on LP sows (P < 0·05 and < 0·001 respectively). More piglets were weaned by HP sows than LP sows (P < 0·05). HP sows gained more weight in pregnancy (P < 0·001) which was slightly longer, and lost more weight in lactation (P < 0·05) than LP sows.The HL pattern of feeding was associated with smaller live weight gains in pregnancy than the LH pattern (P < 0·001) and the total birth weight of HL litters was lighter than LH (P < 0·05), mean piglet weights being similar. Lactation performance was unaffected by pattern treatment.The main conclusion is that a low intake, particularly during the latter half of pregnancy, of protein which is of vegetable origin, is associated with decreased viability of the piglets at birth and in early suckling life, and with lower capacity of the sows for milk production.
Semen characteristics of Awassi rams
Authors: Juma K. H. , Dessouky F. 
Published: March 2009

SUMMARYOn the College of Agriculture farm in Abu-Ghraib 147 ejaculates were collected from three docked and four normal Awassi rams born during November 1962. The work covered a period from 1 April 1967 to 31 March 1968.Nine semen characters, namely, volume, mass activity, individual motility, sperm concentration, sperm number, pH, methylene blue reduction time and the percentages of abnormal and dead sperms, were studied. The effect of season and docking on these characters was investigated.Seasonal variation was observed in all traits studied. On the whole, semen quality was poorest during winter and best during summer. The effect of docking was more pronounced on sperm concentration, sperm number and percentage of abnormal sperms. Docking appeared to increase sperm production and reduce sperm abnormality.
Experiments in selecting for resistance to downy mildew in sugar beet
Authors: Russell G. E. 
Published: March 2009

SUMMARYIn tests with seedlings in the glasshouse, significant differences in susceptibility to downy mildew, caused by Peronospora farinosa f. sp. betae, were observed between individual stocks of sugar beet. The resistance of a particular stock in glasshouse tests was not always a reliable guide to its resistance in the field. There were also serious discrepancies between the results of tests with seedlings and those with mature plants in the field, suggesting that the resistance of certain stocks, relative to one another, may vary with increasing age of the host plant. This contention was supported by evidence from a field experiment in which the susceptibility of several sugar-beet stocks was compared throughout the growing season. It also appears that changes in environmental conditions affected resistance to downy mildew more in some stocks than in others.Progenies of selected plants that had not shown severe symptoms of downy mildew, after exposure to natural inoculation with P. farinosafor more than 3 months in the field, were much more resistant than the parent stocks. This showed that a single generation of selection under suitable conditions can significantly improve the resistance of sugar-beet breeding stocks to downy mildew.An inbred sugar-beet line of American origin showed exceptional resistance to downy mildew in experiments under glass and in the field. Inoculated plants of this line usually showed no symptoms of the disease and P. farinosa did not produce conidia on them. These results show that sources of extreme resistance are present in cultivated sugar beet and suggest that an excellent control of downy mildew in Britain may eventually be achieved through the use of resistant varieties.
Differences amongst breeds of sheep in food requirements for maintenance and live-weight change
Authors: Doney J. M. , Russel A. J. F. 
Published: March 2009

SUMMARYIn a series of experiments, each of 6 weeks' duration, non-pregnant Romney, Scottish Blackface and Tasmanian fine-wool Merino ewes were individually penned in an outdoor environment and allocated a constant ration within a range from 8 to 30 g of a standard dried-grass pellet per kg live weight. Maintenance requirements were calculated from the regression of live-weight change per unit weight on intake per unit weight. Comparable values for the three breeds were computed as 8·4, 9·2 and 14·0 g DOM (digestible organic matter)/kg/day for Romney, Blackface and Merino respectively, the latter being significantly higher than for the two British breeds. Estimates of requirements per unit change in live weight, after allowing for maintenance, were 5·1, 4·6 and 3·0 g DOM/g live-weight change for the three breeds. Methods of estimation of energy requirements and the reasons for differences between breeds are discussed.
Availability of phosphate as affected by duration of fertilizer contact with soil
Authors: Devine J. R. , Gunary D. , Larsen S. 
Published: March 2009

SUMMARYThe changes in phosphate availability that occurred when fertilizer phosphate was incorporated in moist uncropped soil were examined by storing fertilized soil in the open for periods up to 3 years before a final test crop was grown. Superphosphate was the standard source as it was fully available initially and therefore provided a measure of the rate of immobilization of phosphate on the four soils used. The extent to which this rate was modified by slower rates of dissolution of non-water-soluble sources was examined, using dicalcium phosphate (powder and granular), basic slag and ground North African rock phosphate (GNAP).Powdered dicalcium phosphate and basic slag in general behaved similarly to superphosphate, indicating very rapid dissolution. The only exception was a slightly lower rate of dissolution of slag on the calcareous soil. Other than in the very acid soil, the rate of dissolution of GNAP was slow so that the available phosphate was not similar to the superphosphate treatment until after at least the second year. On the calcareous soil GNAP was practically inert. Granular dicalcium phosphate was the only consistent slow-release source. It gave available phosphate levels which were initially lower, but subsequently higher, than those from superphosphate. In the absence of a crop, cumulative assessments of phosphate availability were not possible.The pertinence of these results to the problem of maintaining a high soil phosphate status is discussed.
Nitrate nitrogen in leaves and petioles of sugar beet in relation to yield of sugar and juice purity
Authors: Last P. J. , Tinker P. B. H. 
Published: March 2009

SUMMARYThe use of the correct N dressing for beet is important, as any excess decreases juice purity and profit, and may decrease sugar yield, but no analytical method will at present predict the best dressing in any particular field. The concentration of nitrate in leaves and petioles of beet was determined to test if it would determine the need for top-dressings of N. Beet on seventeen field trials in 3 years testing N were sampled. Nitrate in a wet tissue extract was determined by reducing to ammonia with titanous sulphate and subsequent distillation.The petiole nitrate concentration decreased sharply with time, from around 1000 ppm in wet tissue in early June to less than 100 ppm in early September. The nitrate concentrations were closely related to nitrogen dressing, and the rapid decline in concentration was decreased by top-dressings. Comparison of samples taken in June showed that most of the variation between the experiments could be accounted for by the different ages of the plants. Sodium fertilizer had no effect on nitrate content.Petiole nitrate was inversely related to juice purity and sugar concentration, especially when the nitrate content exceeded 700 ppm in June.On average, petiole nitrate concentrations about 800 ppm in June were associated with the largest sugar yields, but the content could not be used to predict nitrogen top-dressing requirement accurately at individual sites.Measuring NO3-N cannot at present be recommended as a method for deciding how much nitrogen fertilizer to use, but it has value for detecting severe deficiencies and in research.
Yield and quality components in maize grown for silage
Authors: Thomson A. J. , Rogers H. H. 
Published: March 2009

SUMMARYResults from three trials are presented. The main variables were date of harvest, plant density and variety. Measurements were made of whole-crop yields and yields from plant fractions (leaf, stem, cob). Quality components—digestibility, acid-pepsin solubility, water-soluble carbohydrates, nitrogen and ash—were estimated for whole crop and fractions. There were successive samplings for quality components.Whole-crop yield from fractions and yield of quality components increased with density. Whole-crop yield differed significantly with harvesting date as did all fractions except cob, although the proportion of cob increased with time. The earlier harvesting date gave greater yields of quality components.There was no effect of density on the dry-matter content but later harvesting resulted in higher dry matter.The only quality component affected by density was nitrogen content but there were large effects of harvesting date on digestibility and the acid-pepsin components.Regressions were computed for quality components on dry-matter proportion of cob and the dry-matter content of the whole crop. Regressions were significant for the acid-pepsin soluble components and the water-soluble carbohydrate component on the proportion of cob. Regressions of digestibility and pepsin-soluble components (total and organic) on dry-matter content were significant.The implications of these findings to the breeding of maize varieties are discussed.
The influence of density and nitrogen in seed production stands of S48 timothy (Phleum pratense L.) and S215 meadow fescue (Festuca pratensis L.)
Authors: Lambert D. A. 
Published: March 2009

Seed production stands of S 48 timothy and S 215 meadow fescue were obtained with varying plant densities by utilizing two driE widths, removing sections of drill, or oversowing drilled material.Annual tiller counts were made in preselected quadrats, and performances of tiller populations were assessed from these quadrats.
Genetic control of blood potassium concentration in Welsh Mountain sheep
Authors: Khattab A. G. H. , Watson J. H. , Axford R. F. E. 
Published: March 2009

The distribution of whole blood potassium concentration in 1783 Welsh Mountain sheep shows marked bimodality, varying about two modes, of 44 and 14 m-equiv./l.The difference between high (HK) and low (LK) potassium types was not clear-cut. About 5 % of animals lay in the area where the tails of the two distributions merge.Haematocrit values and plasma potassium concentrations were used to estimate erythrocyte potassium levels. They confirmed that the bimodality is due to variation within erythrocytes but did not offer a satisfactory method of allocating intermediate animals.
Variation in the mineral and crude-protein content of pastures at Muguga in the Kenya highlands
Authors: Howard D. A. , Burdin M. L. , Lampkin G. H. 
Published: March 2009

1. Variations in the crude-protein and mineral content of pastures at Muguga are described.2. At all times sodium appeared to be inadequate, and during dry periods phosphorus and crude protein were also apparently deficient.3. Except for sodium and calcium, the amounts present of all substances determined largely depended upon the amount of recent rain.4. The difficulties of interpreting such data have been considered.
Variation in efficiency of food utilization in twin calves II. The effect of live weight and feeding rate
Authors: Taylor C. S. , Young G. B. 
Published: March 2009

The relationship of efficiency to weight and feeding rate has been studied in 38 twin calves from 2 to 18 weeks of age. Following birth or weaning heavier animals were more efficient, but tended to be slightly less efficient when fully established on a diet. On balance, they possessed an advantage.Heavier twins and heavier pairs were also on average more efficient. The increase in mean efficiency for contemporary animals was about 1% for each 1 lb. superiority in weight over the 4-month period. These results contrast with the well-known decline in efficiency as animals increase in weight. Different pairs declined in efficiency with increasing live weight at distinctly different rates judged by the resemblance of twin and co-twin, but evidence for genetic control was slight.More efficient animals were associated with a relatively more rapid decline in efficiency, leading to a general convergence in efficiency as animals grew heavier.The relationship of efficiency to feeding rate was very similar to the relationship with weight.
Field experiments comparing the effects of muriate and sulphate of potash on potato yield and quality
Authors: Dickins J. C. , Harrap F. E. G. , Holmes M. R. J. 
Published: March 2009

1. Between 1955 and 1961 nineteen experiments were carried out on Majestic potatoes in various parts of England comparing muriate and sulphate of potash at three rates of application, in the range 75–336 lb./acre of K2O. Most of the experiments were on light soils.2. Total yield of tubers was on average the same from both sources at all rates of application, and this similarity was not affected by environmental conditions.3. Muriate of potash consistently gave a higher yield of large tubers than sulphate, with an average difference of 0·6 ton/acre. Conversely, muriate gave a lower yield of medium tubers than sulphate, again with a mean difference of 0·6 ton/acre.4. Muriate of potash significantly depressed tuber dry-matter content in eleven of the experiments, particularly at the higher rates, while sulphate had this effect in three experiments. Muriate gave a small increment in two experiments, at low rates only, while sulphate had this effect in five, most markedly at low rates. Sulphate gave a higher dry-matter content than muriate in most of the experiments. The mean difference was 1·0% at 300 and 336 lb./acre of K2O and 0·4 to 0·5% at lower rates.5. Sulphate of potash gave a more floury texture to the boiled tubers than muriate in three experiments, but otherwise no difference in texture was detected between the sources.6. The degree of off-flavour was not appreciably affected by rate or source of applied potash.7. After-cooking blackening was more marked at low than at high rates of applied potash in seven of the nineteen experiments. Muriate and sulphate of potash had similar effects.8. Farmyard manure ploughed down in winter was tested in three experiments and did not influence to any important extent the relative effects of muriate and sulphate of potash on tuber yield and quality.9. Application of the two sources on the flat before ridging and in the open drills was compared in the same three experiments, but did not alter the relative effects of the sources on yield or dry-matter content.