bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies of compensatory growth in sheep
Authors: McManus W. R. , Reid J. T. , Donaldson L. E. 
Published: March 2009

SUMMARYA number of observations have been made on 5- to 6-month old wether Hampshire heep undergoing uninterrupted growth (36·2% gain in shrunk wool-free live weight over 58 days), undernutrition (a 21·7% fall in body weight over 27 days) and then followed by compensatory growth (a gain of 62·2% in live weight over 52 days).Sheep being underfed had increased, and compensating sheep had decreased, apparent digestibility coefficients of feed dry matter compared to control sheep. Sheep undergoing compensatory growth drank more water, ingested more food per unit body weight, laid down less body fat, more protein and retained more water in their bodies than did control sheep. Tritiated water allowed estimation of total body water with an accuracy comparable to other reports in the literature.Changes in the weight and in RNA-P and DNA-P content of anterior pituitary, thyroid and adrenal glands were measured. Sheep thyroid glands were examined histologically to assess relative TSH outputs and no significant differences detected.Rat bio-assay of cavernous sinus plasma for somatotrophin and ACTH activity was made on these sheep. Somatotrophin was detected, but experimental groups did not statistically significantly differ in relative potency (TJ.S.P. units/ml fresh plasma). Compensating sheep had. significantly lower plasma somatotrophin potency per unit empty body-weight values than did the underfed sheep.No ACTH activity was detected in the sheep plasma of the several groups.During severe undernutrition the anterior pituitary gland decreased in size, but not in cell numbers, and still elaborated somatotrophin. Decrease in body size tends to increase the ratio of circulating somatotrophin per unit body size and thus may facilitate, in a permissive manner, the enhanced growth rate of animals undergoing compensatory growth.Restitution and gain of body size by compensatory growth is accompanied by hypertrophy of the anterior pituitary gland. This gland, after compensatory growth, showed evidence of enhanced synthesizing capacity.
The effects of diet supplements and gamma irradiation on dissimilation of low-quality roughages by ruminants: II. Effects of gamma irradiation and urea supplementation on dissimilation in the rumen
Authors: McManus W. R. , Manta L. , McFarlane J. D. , Gray A. C. 
Published: March 2009

SUMMARYResults of two in vivo sheep experiments in which gamma-irradiated material in teryleno bags was fermented in the rumen are reported.Exp. I concerned the testing of rice straw, nassella (Nassella trichotoma) and cotton lint, each subjected to six dose levels of gamma irradiation (0, 5, 10, 25, 100 and 200 Mrad) when wet and when in the dry state. The tests were made in sheep fed either a lucerne hay or a rice-straw base diet.Dry -matter disappearance of all test materials was influenced by irradiation treatment: levels of 10 and in some instances 25 Mrad depressed, and other levels substantially enhanced, intraruminal degradation rate tested over 72 h. Materials irradiated in the dry state were better dissimilated than those irradiated in the wet state.On severe shaking for 14 h in water, solubility values as high as 35 % were obtained for irradiated test materials receiving the highest dose of irradiation but such values were never of the same magnitude as total dry-matter losses in the rumen. When irradiated material was immersed in gently flowing water for 12 h solubility values of 1 % were found for material dosed at 100 or 200 Mrad and of nil for other dose levels. At no level of irradiation was solubility depressed. It was concluded that enhanced losses of irradiated dry matter in the ruminal environment arose substantially from fermentation.Intraruminal dissimilation of irradiated test material from terylene bags was always greater on lucerne hay base diets than on rice straw base diets.Exp. II investigated the influence of urea supplementation, at levels of 1 % and 2 % of diet, on the dissimilation of irradiated test samples of cotton lint and rice straw for sheep fed a rice-straw base diet.Similar effects of irradiation on cotton lint and rice straw to those found in Exp. I were observed. Overall, urea supplementation depressed dissimilation rate of rice straw and severely depressed degradation of cotton lint irrespective of irradiation dose up to an irradiation dose level of 100 Mrad. It is concluded that urea supplementation per se depressed the activity of cellulolytic organisms.It is considered that feeding trials with low-quality roughages irradiated at levels at or greater than 25 Mrad are warranted.
High Level Cereal Diets for the Growing/Finishing Pig: VI. An Evaluation of Flaked Maize, Wheat and Barley When Included at High Levels in the Diet of the Weaned Pig Grown to Cutter Weight (160 lb)
Authors: Lawrence T. L. J. 
Published: March 2009

SUMMARYIn a randomized block 3x2 factorial experiment 72 Large White type and Large White x Landrace pigs were restrictedly fed to 160 lb (72–5 kg) live weight on diets (as wet mashes) containing high levels of maize, wheat or barley in either ground meal or ground flaked forms. A further five groups of six litter-mate Large White type hog pigs per group were used in digestibility and nitrogen balance studies. The diets of meal were formulated to be iso-nitrogenous and to contain similar levels of lysine and for each cereal similar levels of protein and vitamin/mineral supplements were included in the flaked diets. There were no significant cereal x processing interactions for any of the parameters studied. Overall, flaking improved digestibility and this was reflected in a higher (P >0-05) digestible energy content of the flaked diets (3402 kcal/kg air dry weight) compared with the meal diets (3334 kcal/kg air dry weight). The digestible energy contents of the maize, wheat and barley diets were significantly different (P < 0-001) at 3477, 3431 and 3195 kcal/kg air-dry diet respectively. Nitrogen retention, growth rate and efficiency of food conversion were all significantly poorer for the flaked, compared with the meal based diets. The nitrogen retained from the wheat-based diets was significantly lower than that retained from the maize- and barley-based diets. Growth rates of pigs given the wheat- and barley-based diets were similar but taken together were significantly (P < 0-05) better than those obtained from pigs given the maize-based diet. Efficiency of food conversion followed a similar pattern but the differences were not statistically significant.
The effect of the intensities of potassium and sodium in soil on the growth of sugar beet
Authors: Rowell D. L. , Erel Kamil 
Published: March 2009

SUMMARYIn a pot experiment, the growth of sugar beet on one soil with three levels of exchangeable Na ceased when the intensity of K measured as the activity ratio aK/√[a(Ca + Mg)] in the equilibrium soil solution had fallen to 6 × 10–4 (mole per litre)½;, the intensity of Na, aNa/√[a(CaH-Mg)], to between 1·7 and 4 × 10–3 (mole per litre)½;and exchangeable Mg to 0·14 m-equiv per 100 g soil. It was concluded that both the Na and the K intensities were exhaustion values but that K supply was preventing further growth. The additions of Na did not affect either yield or the uptake of K, Mg and Ca, but more Na was taken up from soils with higher Na levels.
The influence of nutrition during winter on growth rate and sulphur content of wool of pregnant Scottish Blackface and Romney ewes
Authors: Doney J. M. , Evans C. C. 
Published: March 2009

SUMMARYPregnant ewes of the Scottish Blackface and Romney breeds were group fed to achieve different patterns of live-weight change between mating and parturition. One group had a net maternal live-weight increase of about 8%, the second a net loss of about 5% and the third a loss of about 16%. Wool growth and sulphur content of the wool were measured at intervals. During the period 6–8 weeks prepartum wool growth rate in the Blackface breed was low and there were no significant differences amongst treatments. Differences in sulphur content were highly significant (ranging between 3·97 and 3·46% for fine and coarse fractions respectively in the well-nourished sheep down to 3·68 and 3·20% in the undernourished group). In the Romney breed the situation was reversed. In the prepartum period there were no significant differences amongst groups in sulphur content (mean value 3·68%), but differences in wool growth rate were highly significant (0·021, 0·012 and 0·009 g/100 cm2/day).
Aspects of the agronomy and genetics of quality components in a diallel set of progenies of Lolium perenne L.
Authors: Rogers H. H. , Thomson A. J. 
Published: March 2009

SUMMARYSelfed and diallel progenies of selected clones of Lolium perenne were subjected to four nitrogen rates—0, 225, 450 and 675 kg/ha of N per annum. The herbage was analysed for total nitrogen (N), digestible dry matter (DMD), digestible organic matter (D) and acid-pepsin solubility was determined on total (PS) and organic matter (POMS) in 1967 and 1968.Data for the percentage composition and the yield of quality components are presented with the variances of general (g.c.a.) and specific (s.c.a.) combining abilities for these characters. The g.c.a. and s.c.a. interaction with nitrogen is partitioned.For percentage quality components and yields there were significant effects of years, nitrogen rates, progenies and their interactions. The variance for g.c.a. for all percentage quality components was not significant in 1968 but in 1967 all were significant except for total N. For yields, only the g.c.a.'s for PS and POMS were significant in 1967: no g.c.a.'s were significant in 1968.There were considerable differences between years for heritability values. For digestibility the predicted performance of a theoretical F2 synthetic was little better than the mean of the population from which it was derived.The implication of these studies in the formulation of a grass breeding programme is outlined.
Interactions between the beneficial effects of nitrogen, phosphate and potassium on plant growth
Authors: Wood J. T. , Greenwood D. J. , Cleaver T. J. 
Published: March 2009

SUMMARYSets of data were selected from 66 nutritional experiments on crop plants with large beneficial effects of at least two of the nutrients, nitrogen, potassium and phosphorus, and the data, the logarithms of the data, and the reciprocals were statistically analysed. It was shown that the beneficial effects of the nutrients were additive much more often on the reciprocal scale, than when a logarithmic transformation, or none at all, was used.
Rapid reduction of nitrate in soil re-moistened after air-drying
Authors: Cawse P. A. , Sheldon D. 
Published: March 2009

SUMMARYWhen an organic calcareous soil was air-dried for 2 days and re-wetted to a wide range of moisture contents, well below saturation, nitrite accumulated within 1–2 days. At the same time much nitrate was formed and more carbon dioxide was released than from soil kept moist. On further incubation of re-wetted soil for 3–5 days, the nitrite concentration decreased rapidly. Since 15N-labelled nitrate was reduced to nitrite after air-drying and re-wetting, and no nitrite was formed in autoclaved soil, nitrate was microbially reduced.Eighty-three per cent of added 15N tracer was recovered from the soil 2 days after re-wetting to 70 % moisture, indicating that 58 ppm N had been lost; 10 ppm N of this was released as nitrous oxide. Autoclaved soil to which nitrite was added did not evolve nitrous oxide, suggesting that nitrite was reduced biologically rather than decomposed chemically.Three other soils were treated similarly; two, which were non-calcareous, accumulated no nitrite. Fresh calcareous soils with high respiration rates and good capacities to denitrify when waterlogged are most likely to form nitrite after drying and moderate re-wetting.
Effect of disease on the oestrogenic activity and coumestrol content of white clover and lucerne
Authors: Saba N. , Drane Hilary M. , Hebert C. Nancy , Newton J. E. , Betts J. E. 
Published: March 2009

SUMMARYThe oestrogenic activity and coumestrol content of ‘diseased’ and ‘clean’ white clover and lucerne were investigated. It was found that both coumestrol content and oestrogenic activity were increased in diseased white clover. However, there was insufficient coumestrol to account for the oestrogenic activity and it was suggested that other factors (e. g. oestrogen potentiator, unidentified oestrogen) were involved.
The effects of grazing intensity on herbage consumption and animal production: IV. An evaluation of two methods for avoiding the rejection of fouled herbage by dairy cows
Authors: Reid G. W. , Greenhalgh J. F. D. , Aitken J. N. 
Published: March 2009

SUMMARYFor phase I of a rotational grazing experiment (three grazing cycles; May–July) a group of nine cows (group S) were ‘conditioned’ to eat fouled herbage by being allowed to graze only on slurry-treated pasture (area 1), and two further groups of nine (groups H and C) grazed on an adjacent area (2) of untreated pasture. One-third of area 2 was harrowed after each grazing. During phase II (the fourth grazing cycle; August) group H grazed on the harrowed part and groups S and C grazed on the remainder of area 2. The herbage allowance was 15 kg dry matter per cow per day in phase I and 12 kg in phase II.In phase I, group S cows ate significantly less than groups C and H combined (9·2 v. 10·5 kg organic matter per day), and lost weight (– 0·37 v. + 0–03 kg/day), but their milk yields were not significantly lower (16·1 v.16–6 kg/day). In phase II neither intake nor milk yield differed significantly between the three groups, but group S cows gained weight while the other two groups lost weight.It was concluded that neither conditioning the cows nor harrowing the pasture was an effective means of avoiding rejection of fouled pasture.
Yield, leaf-area index and photosynthetic rate in some perennial ryegrass (Lolium perenne L.) selections
Authors: Rhodes Ian 
Published: March 2009

SUMMARYYield, critical LAI and apparent photosynthetic rate per unit leaf area were measured in four families selected from L. perenne S. 321. Differences in yield were attributable to differences in canopy structure producing differing critical LAI. The most productive family, which was 33% more productive than the base population, produced the largest critical LAI but had the lowest photosynthetic rate.
The effects of partial suckling on the lactation performance of Chios sheep and Damascus goats and the growth rate of the lambs and kids
Authors: Hadjipanayiotou M. , Louca A. 
Published: March 2009

SummaryTwo trials with 82 and 54 Chios ewes and one with 44 Damascus goats were conducted during 1973–4 to study the effects of partial suckling on lactation performance and the growth rate of the lambs and kids. The treatments studied were: (a) continuous (24 h a day) suckling; (b) partial (8 h a day) suckling and (c) partial with decreasing duration of suckling from 8 h daily to residual suckling, i.e. 20 min after each milking.No significant differences were found in either the 35-day milk yields (commercial milk yield+milk sucked) of ewes or the 70-day milk yields of goats between animals suckling continuously and those suckling partially. However, the 35-day and 70-day commercial milk yields of ewes and goats on the partial suckling treatments were significantly higher than those of ewes and goats on the continuous suckling treatment. Residual suckling of ewes from 36 to 120 days after lambing resulted in an increase in the total milk yield but not in the milk sold. Significant differences in milk yields were found between ewes nursing one and those nursing two lambs. The corresponding mean values for the 35-day milk yield were 78 and 94 kg and those for the 120-day milk yield 205 and 238 kg.Up to weaning (35 days for sheep and 70 days for goats) the growth rate of lambs and kids on the partial suckling treatments tended to be poorer than that of those on continuous suckling. After weaning, however, the growth rate of the partially suckled lambs and kids as well as that of the lambs on residual suckling from 36 to 120 days were as good as that of those suckling continuously so that the differences in the final weight were not significant.It is concluded that partial suckling in sheep and goats is profitable in the early stages of lactation provided that the milk left to the young and the intake of solid feed are sufficient to sustain satisfactory growth.
Developmental characteristics of grass varieties in relation to their herbage production: 2. Spring defoliation of Dactylis glomerata: the fate of reproductive tillers which are cut, but whose stem apex is retained
Authors: Davies I. 
Published: March 2009

SummaryEarly stages in the development of reproductive tillers of cocksfoot were studied in uncut swards, and in regrowth after cuts taken at a critical stage.In uncut swards, initial stages of stem extension (up to 10 cm) occurred over 3 weeks. During this period the last three or four leaves initiated on the tiller became visible externally. Tillers with stems of less than 2 cm generally had one or two partially emerged blades. Those with stems 2–6 cm long carried two, three or, occasionally, four partially emerged blades; the sheaths of two, and sometimes three of these leaves extended beyond the stem apex. Hence, for tillers with 2–6 cm stems, even lenient defoliation involving the removal of only one expanded blade would result in the severance of a further two, three or four developing leaves; at an earlier stage only one or two developing leaves would be severed.In the regrowth studies it was found that defoliation of reproductive tillers whose apices were below cutting height and which, at the time of cutting, had stems of up to 8 cm, led to contrasting effects: some made only negligible regrowth, whilst others made rapid extension growth. Some of the most rapidly extending tillers retained no leaf blades, and therefore the alternative effects of defoliation cannot be completely explained in terms of leaf retention. Other possible mechanisms contributing to these effects are discussed.
The effect of density of planting on the growth of two Phaseolus vulgaris varieties in England
Authors: Lucas E. O. , Milbourn G. M. 
Published: March 2009

SummaryThe growth and development of two varieties of Phaseolus vulgaris (Purley King and Limelight) were compared in two experiments in 1973 and 1974 at a range of planting density from 20 to 100 seeds/m2. Within this range, the relationship between seed yield and density in Purley King was asymptotic, although there was a suggestion that if even higher densities had been tested, a downward trend in yield might have occurred. The optimum density of planting for Purley King in Expt 1 was 50 seeds/m2 while that for Limelight was 40 seeds/m2. The corresponding densities in Expt 2 were 75 and 50 seeds/m2 respectively. Although number of branches per plant generally decreased with increasing density, there was no significant density effect on the number of nodes per plant. Thus stabilization of seed yield occurred even at quite low densities. Although in the low-density treatments, less vegetative tissue was produced, the peak of dry-matter yield occurred later after flowering and the slower subsequent senescence ensured the presence of active photosynthetic tissue throughout the pod-fill stage. Less pod retention occurred at high density which, combined with the ability of widely spaced plants to produce pods over a longer period, resulted in a similar number of pods per unit area over a wide range of density.Although the variety Purley King produced more than double the number of mature pods from its extra nodes and branches, it was outyielded by Limelight by 35% from the combined effect of more seeds per pod and a higher mean seed weight. Limelight also produced this high yield with less vegetative tissue. In both varieties it appeared that pod photosynthesis could take place, in Purley King because the pods were borne on higher nodes above the canopy and in Limelight due to the earlier senescence of its smaller leaf area. However, in spite of the apparent physiological advantages of Limelight, the pods are not borne high enough on this plant to enable satisfactory mechanical harvesting.
Effects of pre-mating environmental stress, ACTH, cortisone acetate or metyrapone on oestrus and ovulation in sheep
Authors: Doney J. M. , Gunn R. G. , Smith W. F. , Carr W. R. 
Published: March 2009

SummaryAdministration of ACTH to Finnish Landrace × Dorset Horn ewes during days 13–16 of the pre-mating oestrous cycle resulted in a significant delay in the onset of oestrus (mean cycle length of 17·5 ± 0·39 days as compared with 16·4 ± 0·61 in a control group). Subsequent ovulation rate was significantly higher than in the control group (3·12 and 2·44 ova/ewe respectively).In a second experiment with Scottish Blackface ewes the effects on time of onset of oestrus and on ovulation rate of environmental stress, ACTH, cortisone acetate or metyrapone were studied. Environmental stress and administration of ACTH through the oestrous period significantly reduced ovulation rate (1·54 and 1·39 ova/ewe respectively) compared with the control (1·96). ACTH administered during days 13–16, as in the first experiment, and cortisone acetate administered through oestrus had no effect on ovulation rate (1·88 and 1·86 respectively). Administration of metyrapone reduced ovulation rate to 1·70 but this was not significantly different from the control. Both forms of ACTH treatment resulted in a delay in onset of oestrus but environmental stress had no effect on this character.Levels of plasma luteinizing hormone (LH) were estimated on representative animals. These showed that ACTH and environmental stress influenced the pattern of the ovulatory surge of LH in respect of time of onset of the surge relative to onset of oestrus, duration of surge and peak levels.
Effects of post-mating environmental stress or administration of ACTH on early embryonic loss in sheep
Authors: Doney J. M. , Smith W. F. , Gunn R. G. 
Published: March 2009

SummaryIn two separate experiments, ewes of the Scottish Blackface breed were subjected to management stresses in the first or second 10-day period after mating or were treated with daily injections of 60 i.u. ACTH for the whole 20-day period. Embryonic loss is defined as the number of corpora lutea not represented by viable embryos at slaughter. Examinations were carried out between 26 and 32 days post-mating. In the two experiments combined, losses were 29·9, 29·0, 37·7 and 17·2%, respectively, for ewes subjected to environmental stress during days 1–10, during days 11–20, treated with ACTH or kept as unstressed control. Expressed as the percentage of ewes in which partial or complete loss of shed ova occurred, the results were 49·0, 46·0, 54·3 and 25·5%, respectively. Losses were significantly higher in all treated groups than in the unstressed control.