bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of penis and sheath in the bull calf
Authors: Ashdown R. R. 
Published: March 2009

1. The penises of five bull calves were examined during the first year of life, using epidural anaesthesia or sedation with chlorpromazine hydrochloride.2. The process of separation between penis and sheath is described and data on age and weight of the calves are given.3. There was considerable variation in times and rates of development, but in general terms the penis began to separate from the sheath at about 4 months of age, and the process was completed at about 10 months.4. From the second to the sixth or seventh month of life the penises of these calves were short, and not manually protrusible.
The influence of temperature on flowering in species of Lolium and in Poa pratensis
Authors: Evans L. T. 
Published: March 2009

The influence of various night- and day-temperature regimes on inflorescence initiation and earing in vernalized and unvernalized Lolium temulentum, L. multiflorum, short-rotation ryegrass, and two varieties of L. perenne, and also in the Athabasca strain of Poa pratensis, is described.Vernalization response curves for the ryegrasses, when grown under controlled conditions, are presented, and are consonant with the operation of a first-order reaction as the rate-limiting step in the vernalization ofLolium perenne. Velocity coefficients for the rate of vernalization in various conditions are deduced, and are shown to be higher in seedlings than in seeds, and higher in short days at 10° C. than at 4° C. The Q 10 for the velocity of vernalization over this range is about 2·7.Low-temperature vernalization in L. perenne can occur when low night temperatures are combined with moderately high day temperatures, and it can take place during abundant vegetative growth. In short days and in continuous light mean temperatures up to 10° C, at least, are fully effective, but in 16 hr. photoperiods even 7° C. was not a fully effective vernalizing temperature. The requirement of perennial ryegrass plants for cold treatment may be replaced by short-day induction if light intensities are low and if the plants are continually divided.
The value of calcium nitrate and urea for main-crop potatoes and kale
Authors: Widdowson F. V. , Penny A. , Cooke G. W. 
Published: March 2009

1. Twenty-two experiments on main-crop potatoes in 1955–7 compared calcium nitrate and ammonium sulphate applied to the seedbeds before planting. Urea was also tested in fifteen of the experiments in 1956–7. The three fertilizers were compared at rates that supplied 0·5, 1·Oand 1·5 cwt. N/acre.2. Seven experiments on kale in 1955–8 compared seedbed dressings of calcium nitrate and ammonium sulphate. Urea “was also tested in. five of the experiments in 1956–8. The rates used were 0·6, 1·2 and 1·8 cwt. N/acre in 1955 and 1·0 and 2·0 cwt. N/acre subsequently. Single dressings applied to the seedbed were also compared with divided dressings applied partly to the seedbed and partly in mid-season.3. Generally the potatoes gave only small responses to N; there was no worthwhile gain from applying more than 1·0 cwt. N/acre in 1955 and 0·5 cwt. N in 1956 and 1957. Nitrogen gave much larger proportionate increases in yields of kale, at several of the centres crops continued to respond up to dressings of 2·0 cwt. N/acre.4. Calcium nitrate generally gave lower yields of potatoes than ammonium sulphate and the superiority of ammonium sulphate was greater with the higher dressings. Losses in yield with the nitrate were usually associated with a severe check to early growth occurring in dry springs and with dressings concentrated close to the seed, but lower yields were also obtained at some centres where early growth was not damaged. Calcium nitrate and ammonium sulphate were roughly equivalent for kale when the nitrate did not damage germination; heavy seedbed dressings of the nitrate reduced kale plant numbers severely unless there was adequate rain after sowing.5. Granulated urea tested in 1956 contained 4·5% of biuret, it delayed emergence and reduced plant establishment seriously in several of the potato experiments; damage increased with the level of manuring and was accentuated when dressings were broadcast over furrows before hand-planting. Yields given by this batch of urea were less than with other N fertilizers and when 1·5 cwt. N/acre was applied they were less than with no nitrogen at all. Purer crystalline urea (having less than 1% of biuret) used in the 1957 experiments caused no damage to emergence of potatoes and gave yields similar to those obtained with ammonium sulphate. There were similar effects in the kale experiments; granulated urea containing much biuret damaged germination severely in 1956; the purer products containing little biuret used in later years reduced plant numbers at one centre in 1957 and at the single 1958 centre. Where there was no damage to the establishment of kale, urea and ammonium sulphate gave similar yields.6. Dressings applied partly to the seedbed and partly in mid-season gave slightly higher average yields of kale than an equivalent total amount of nitrogen all applied before sowing.
The effect of management factors on the intestinal bacteria and the growth rate of chicks
Authors: March B. E. , Goudie C. , Biely Jacob 
Published: March 2009

1. The apparent cleanliness of the premises in which chicks are reared has little bearing on the growth rate of chicks within a given environment.2. Bacterial counts of faeces from chicks reared under clean or extremely contaminated conditions showed no difference between the two sets of conditions.3. Delaying feeding until 72 hr. after hatching retarded growth to at least 7 weeks of age. If the age of the chicks was calculated from the time at which the chicks were fed rather than the date of hatch, the weights of the chicks fed 72 hr. after hatching corresponded with those of the chicks fed immediately.4. The contents of the duodenum and mesenteric intestine showed higher bacterial counts when feeding was delayed for 72 hr. than when feed was given shortly after hatching. This effect was no longer evident after the chicks were 1 week old.5. Administration of penicillin in the water did not reduce the difference in growth rates between the chicks given feed immediately and those from which feed was withheld.6. Antibiotics may decrease the thickness of the intestinal wall without stimulating growth.
The production of fattening cattle and extension of autumn grazing following three rates of application of nitrogenous fertilizer to a rye-grass/white clover sward
Authors: Tayler J. C. , Rudman J. E. 
Published: March 2009

1. Three levels of a nitrogenous fertilizer, supplying 0,104 and 208 lb. N per acre were applied in 1955 and 1956 to a rye-grass/white clover sward in its fourth and fifth harvest years on a loam soil overlying chalk.2. Levels of animal production were measured using fattening cattle maintained on the plots at a stocking rate of 1⅓ per acre: excess herbage was conserved and fed back to them later.3. Low rainfall in 1955 seriously affected yields of herbage and response to fertilizer, and severely reduced the clover content in all treatments.4. Rate of live-weight gain per head was not reduced by the application of fertilizer at either level. Vigour of the sward was maintained by fertilizer application in a dry spring period in 1956, whereas, in the control treatment, which was low in clover, gains per head were markedly reduced because of inadequate dry-matter production.5. By applying two-thirds of the fertilizer in late summer, a considerable extension of grazing time was obtained, particularly when rainfall was adequate. At the highest level of fertilizer application in 1956 the grazing season was extended from 6 months to 7½, and the cattle continued on conserved feed to a total of 8½ months. Response to the medium and high levels of application on grazed herbage only was 12 and 15 bullock-days per acre, respectively, in 1955. In 1956 the response was 46, and 67/59 (the two high nitrogen treatments). In terms of total live-weight gain per acre the response in 1955 to medium and high levels was 23 and 32% above control, up to 427 lb. per acre: in 1956 it rose to 51 and 52/55% with the highest treatment reaching 657 lb. per acre. Greater financial returns than are indicated by live-weight gain should result from the rising price per pound of carcass as the supply of fresh beef dwindles in early winter.6. Carcass data indicated that both greater rate of gain and the extra time spent on fertilized herbage and conserved feed increased carcass weight and maturity in the normal pattern of development, fat most rapidly, muscle next and bone least. No significant differences in conformation due to treatment was detected by analysis of grouped joints.
An experimental study of the early weaning of lambs
Authors: Wardrop I. D. , Tribe D. E. , Coombe J. B. 
Published: March 2009

Two early weaning experiments are reported. When grazing young, high protein pastures, lambs weaned at 7, 10, 13 and 18 weeks of age grew equally well and there were no significant differences between their carcass weights, grades, and dressing percentages.However, when grazing pastures in the preflowering and flowering stages of growth, lambs weaned at 8 weeks of age did not grow as well as unweaned controls. Their carcass weights, grades, and dressing percentages were also inferior. It is suggested that these differences were primarily due to an inadequate protein intake.No difference in wool production was found either between the ewes of early weaned and control lambs, or between the lambs themselves.
The effect of urea on the utilization of ground, pelleted roughage by penned sheep: I. Food intake, live-weight change and wool growth
Authors: Coombe J. B. , Preston G. K. 
Published: March 2009

SUMMARYIndividually-penned adult Merino wethers were fed for 16 weeks on a basal diet of ground, pelleted oat straw orPhalaris straw. Urea was supplied either in a salt-urea block containing 30% urea, or as crystalline urea incorporated into the pellets. A commercial mineral supplement was given during the first 8 weeks, but this was replaced with a laboratory-prepared mineral mix during the second 8 weeks.Urea supplementation significantly reduced live-weight loss. Over the 16 weeks control sheep lost a mean of 14·5 kg, and supplemented sheep 8·7 kg body weight. Most of this response to urea occurred during the second half of the experimental period.Food intakes of all sheep increased over the first 2 weeks and then fell. In the unsupplemented groups, levels of intake then remained fairly low, whereas in the sheep fed urea food intakes rose over the final 6 weeks of the experiment. There was a significant linear regression of live-weight change on food intake only with the urea-fed sheep. Intakes of urea-N from the blocks were extremely variable between individual sheep and between periods within sheep; in most cases, however, they appeared to be adequate, as this type of supplementation gave results similar to those obtained by mixing urea throughout the roughage.There was no significant effect of urea on total wool growth during the experimental period, although wool growth in the supplemented shepp showed a rise towards the end of the experiment. Wool growth in any 4-weekly period was closely related to food intake and live-weight change during that period.
Visual judgements of quality in meat II. A simplification of the assessment of the proportion of lean to fat in bacon
Authors: Gatherum D. P. , Harrington G. , Pomeroy R. W. 
Published: March 2009

1. The visual judgement of bacon quality called the ‘proportion of lean to fat’ has been simplified by breaking down the overall assessment of the surface seen on the cut bacon side at the last rib into four simpler scores—of the ‘eye’-muscle size and shape, the amount and distribution of fat on the back rasher, the streak thickness and the proportion of lean to fat in the streak, each judged on a 10-point scale. An experiment is described in which eight experienced judges attempted to score these new characteristics in conjunction with the overall assessment.2. The judging standard adopted in the overall assessment of the proportion of lean to fat varied less from batch to batch in this experiment (in which the seven batches were arrayed in fixed positions and assessed in one day) than in an earlier experiment (when the examples seen in each batch could be shuffled and the eleven batches were seen several days apart). The ranking of judges according to their discrimination and repeatability for the overall assessment was also changed in the second experiment.
Studies on the cutting management of grass-clover swards Part II. The effects of close cutting with either a gang mower or a reciprocating-knife mower on the yields from an established grass-clover sward
Authors: Reid D. , MacLusky D. S. 
Published: March 2009

1. In an experiment conducted on an established perennial rye-grass/white clover sward close cutting was carried out over a 3-year period (1956–58), either with a lawn mower to simulate gang mowing or with a reciprocating-knife mower. The sward was cut either six or eight times in each season, and received 0 or 2 cwt. ‘Nitro-Chalk’/acre for each cut.2. Swards cut with the gang mower yielded from 3·5 to 12·5% more herbage dry matter than swards cut with the reciprocating-knife mower and also gave a greater mean yield of crude protein.3. The difference in dry-matter yield between swards cut with each of the mowers is attributed to the slightly closer cutting level of the gang mower having a greater inhibiting effect on flower development in the grasses and hence stimulating leaf production and increasing total yields.4. In the second and third years of the experiment swards cut with the gang mower outyielded those cut with the reciprocating-knife mower by a proportionately greater amount when eight cuts rather than six cuts were taken in the season.5. When no nitrogenous fertilizer was applied the proportion of broad-leaved weeds in the sward increased more rapidly over the 3-year period where the herbage was cut with the gang mower rather than the reciprocating-knife mower. This disadvantage of gang mowing did not apply where the fertility was maintained at a high level by applications of nitrogenous fertilizer.6. It is concluded that the gang mower is a more suitable machine than the reciprocating-knife mower for close cutting on a field scale.
An experiment on the effects of straw ploughed in or composted on a three-course rotation of crops
Authors: Patterson H. D. 
Published: March 2009

An experiment on the use of wheat straw (ploughed in or composted at the rate of 53⅓ cwt./acre every second year) and NPK fertilizers in the maintenance of fertility was carried out at Rothamsted between 1933 and 1958. The effects of these treatments on the yields of the crops of the rotation used in the experiment—barley, sugar beet, potatoes—are discussed in the present paper.The treatments appear to have had no effect on crop yields through improvements to the soil caused by better structure or increased organic matter content. All the effects obtained can be attributed to changes in the supplies of available nutrients. The most important of these changes appear to have been: (1) nitrogen deficiencies due to the immobilization of soil nitrogen or nitrogen fertilizer by the straw: there is some evidence that this added to the store of slowly available nitrogen; (2) additions to potassium supplies from potassium in the straw. Factor (1) affected all three crops. Factor (2) affected potatoes, the only crop of the three to give good responses to potassium.It was found that when the straw was ploughed in directly about 0·08 ewt. N fertilizer applied to the crops for each ton of straw was sufficient to overcome losses in yield due to nitrogen deficiencies. The straw improved the yields of potatoes in the first and second years after application. Provided that allowance was made for losses of available nitrogen the yields of potatoes from ploughed-in straw were about the same as the yields obtained by adding K fertilizer to the crop, equal in amount to the potassium in the straw. When part of the fertilizers was ploughed in with the straw instead of being given directly to the crop the yields of potatoes were reduced.Compost made with NT fertilizers and straw and ploughed in with K fertilizer gave much poorer yields than were obtained by ploughing the straw in directly and applying the fertilizers to the crops. Losses of available nitrogen were severe, all the N fertilizer used in making the compost (0·15 cwt. N for each ton of straw) being either lost through drainage or immobilized by the straw. In addition, more than one half of the potassium in the straw was lost in composting.There was no evidence that any of the nitrogen immobilized in the decomposition of the straw became available in the first or second years after application. Residues from repeated applications of straw every second year over 18 years increased the yields of potatoes and sugar beet in the last 6 years of the experiment. The increases may have been due to the release of previously immobilized nitrogen.
The utilization of irrigated pastures by dairy cows II. The effect of stocking rate
Authors: Freer M. 
Published: March 2009

1. An experiment was carried out over 2 years to study the effect of stocking rate on the efficiency of pasture utilization by dairy cows on irrigated perennial pasture.2. Two matched groups of milking cows grazed throughout the experiment on two unequal areas of pasture at stocking rates of 1·0 and 1·7 cows/acre during the first season and 1·2 and 2·0 cows/acre during the second season (L and H groups, respectively). The same rotational grazing technique was used on both areas.3. In each season the experimental period lasted 249 days. During the first 200 days and 215 days of this period in the first and second seasons, respectively, pasture, grazed or conserved (from the same proportion of both areas), comprised the entire ration.4. The H group produced 57 and 59% more milk per acre than the L group during the first and second seasons, respectively. Milk production per cow in the H group was not significantly depressed. The solids-not-fat content of the milk in both seasons, and the butterfat content in the first season, were significantly depressed at the higher stocking rate.5. The body-weight gain of the cowa in the H group, relative to those in the L group, was depressed by 68% (from 170 to 55 lb./cow) and 88% (from 172 to 20 lb./cow) in the first and second seasons, respectively.6. The yield per acre of utilized pasture, based on the nutrient requirements of the cows, was 39 and 38% higher at the higher stocking rate in the first and second seasons, respectively. The estimated individual intake of these cows in the two seasons was depressed by 14 and 20%, respectively. The estimated yield per acre of utilized pasture ranged from 4092 lb. s.e. at 1·0 cows/acre to 6519 lb. s.e. at 2·0 cows/acre.7. The mean daily herbage intake during the second season, estimated by a herbage clipping technique, was 29·5 and 22·9 lb. dry matter per cow for the L and H treatments, respectively. The cows in the H group ate, at each grazing, all the herbage that had grown since the previous grazing, whereas the estimated intake of the L group was equivalent to only 80% of this regrowth. However, the estimated rate of regrowth of the swards on the two treatments was the same.8. Herbage intake estimates derived from a faecal-indicator technique, and observations of the grazing behaviour of the cows provided more detailed information on the pattern of herbage availability on successive days during the grazing of paddocks at each stocking rate.9. The results of this experiment are discussed in relation to the design of grazing experiments and to farming practice.
Effects of different patterns of allocation of a restricted quantity of food upon the growth and development of cockerels
Authors: Osbourn D. F. , Wilson P. N. 
Published: March 2009

1. The live-weight gains and food consumption of groups of chickens subjected to two different patterns, (A) and (B), of allocation of a restricted quantity of food, were compared with the live-weight gains and food consumption of a control group (C), fed ad lib. throughout the experiment.2. Group B (compensatory growth regime), showed a greater relative growth rate after re-alimentation than group A (mild restriction followed by ad lib. feeding). The growth rate of group B was shown to be significantly greater than that of the control group at equivalent live weights. In addition, it was shown that the increased growth rate, induced by periods of restriction of similar severity and duration, was very similar for birds within the ranges of 200–300 g. live weight and 750–1100 g. live weight.3. The differences, due to treatment, in the growth rate after re-alimentation were in part caused by a concurrent increase in appetite. The severity and duration of the undernutrition immediately prior to re-alimentation would appear to affect appetite during re-alimentation more than the total restriction imposed. Measured in terms of food consumed, the restriction imposed upon groups A and B was the same, but in terms of live weight gain group B was very slightly more retarded than group A.
Observations on the effect of hexoestrol on earthworms and other soil invertebrates
Authors: Raw F. 
Published: March 2009

1. Activity of Lumbricus terrestris, Allolobophora caliginosa and A. chlorotica was unaffected by 15 mg. hexoestrol in solution in 500 g. soil.2. Activity and reproduction of A. caliginosa was unaffected by 10 mg. hexoestrol in 500 g. soil, but 100 mg. and over affected activity and stopped reproduction.3. Egg capsules of A. caliginosa and A. chlorotica developed normally in a saturated aqueous solution of hexoestrol.4. No effect on the soil fauna of grass plots due to grazing with implanted bullocks was observed.
Studies in beef production II. The estimation of live weight of beef steers from chest girth and other body measurements
Authors: Brookes A. J. , Harrington G. 
Published: March 2009

1. Records collected on the steers reared during the long-term experiment on beef production on the Cambridge University Farm from 1946 to 1955 have been analysed to examine the relation of live weight to various body measurements and the dependence of these relations on breed, treatment and age.2. Among the measurements considered singly, chest girth was most closely related to live weight.3. There were marked differences in the slopes of the regression lines relating log live weight to log chest girth during the two phases of the experiment—from birth to 8 months of age and from 8 months to slaughter.4. The regression coefficients in the first period were affected by the treatment on which the calves were being reared. Those in the second period were affected both by the level of feeding the steers were receiving during that period and by the manner in which they had been reared to 8 months.5. Height at shoulder was the measurement which, as a second variate in the regression equations, led to the greatest increases in the accuracy of prediction of live weight. However, the relation of this measurement to live weight was also affected by the treatment.6. It was considered that these measurements show little promise as estimators of live weight which could be generally applied, since their relations to live weight were affected by the treatment of the animal.