bluuebunny/crossref_metadata_2025 huggingface dataset:
Experiments on the effects of phosphate applied to a Buganda soil: I. Pot experiments on the response curve
Authors: Le Mare P. H.
Published: March 2009

In a pot experiment providing for rapid growth of sorghum plants in the red clay loam soils of the Cotton Research Station, Namulonge, in the Buganda Province of Uganda, large yield increases were obtained from added phosphate. In an uncultivated soil which had carried undisturbed natural vegetation (Pennisetum purpureurn)for at least 10 years the response curve had negative curvature throughout. In an arable soil, yields without added phosphate were very poor and the response curve was sigmoid in form. With the arable soil, liming did not modify the form of the response curve for added phosphate but at the heaviest dressing lime decreased yield.
Reaction velocity constants for batch methane fermentation on farms, notably in the tropics
Authors: Boshoff W. H.
Published: March 2009

The gas production in batch fermentation of vegetable matter found on farms is shown to lend itself to the application of monomolecular equations providing an active and well-developed starter material is used for initiating the fermentations. The reaction velocity constants as established for a common material found in the tropics, namely elephant grass, would seem to be some two to five times lower than that previously reported for sewage sludge. The higher rate of decomposition of the sewage sludge is attributed to its more favourable physical condition and possibly also to its greater content of more easily fermentable substances.
The influence of diluents and processing time after ejaculation on the revival of deep-frozen bull spermatozoa
Authors: Martin I. C. A.
Published: March 2009

For highest revival rates in experiments on the deep-freezing of bull spermatozoa to – 79° C., a period of incubation of the undiluted semen at 30° C. did not eliminate the need for overnight equilibration at 5° C. The addition of 1·25% fructose or arabinose to the diluent improved revival rates of non-equilibrated spermatozoa but these rates still did not equal those of equilibrated spermatozoa.

Glycerol apparently penetrated spermatozoa rapidly and spermatozoa survived in glycerol solutions as high as 2·0m if 0·1m buffered citrate was also present. Omission of the citrate solutions caused immediate death of the spermatozoa.

A one-ninth replication of a 37 factorial experiment showed that, by all scoring criteria, 40° C. was superior to 0° C. as a thawing bath temperature. A diluent containing 8% (v/v) glycerol was superior to either 4% or 6% if activity of spermatozoa after thawing was the scoring criterion, but there was no difference in the percentage of spermatozoa stained by congo-red-nigrosin when frozen in diluents containing these levels of glycerol.

In the range of tonicity 80, 100 and 120% (0·9% NaCl = 100% tonicity), using the diluent composed of a mixture of fructose and citrate, there were more motile spermatozoa than in buffered citrate or fructose alone. Increasing tonicity had an adverse effect on revival rates of spermatozoa in the buffered citrate diluent. Spermatozoa stored chilled at 5· C. for periods up to 36 hr. prior to freezing survived best in the mixture of fructose and citrate.

The investigation of the equilibration phenomenon showed that an improvement in survival after deep-freezing occurred if diluted semen was stored for up to 12 hr. after dilution, but this was not dependent on the presence of glycerol in the diluent during this ageing process.
A study of the development of two varieties of maize at Ibadan, Nigeria
Authors: van Eijnatten C. L. M.
Published: March 2009

The very fast development of maize plants at Ibadan, Nigeria, has been described and an attempt has been made to obtain a better understanding of their development with the aid of a growth analysis. Two varieties of maize have been studied, which, again during this experiment, proved to have a very different yielding performance, in spite of a rather similar vegetative development. It was shown that Lagos White, the local variety, produced approximately 2000 lb./acre and ES 2 3000 lb./acre.

From approximately the ninth week onwards the ear starts rapid development, and the retention of a larger functional photosynthetic area by the introduced variety ES 2, from the eighth week onwards, seems to be the major factor controlling its higher production of dry matter in the latter part of development, when compared with Lagos White.

On the average, n.a.r. had similar values in both varieties and had similar deviations at various stages of development; external or internal factors could not be separated. The l.a.r. indicated that, certainly in the latter part of development, ES 2 plants and Lagos White plants had a similar leaf area per gramme of dry matter; but ES 2 had more of both. This factor stresses the similarity of efficiency in both photosynthetic mechanisms.

The l.a.r shows in clear terms the difference between the two varieties grown at equal spacing. The variety ES 2 still increased its leaf area with its additional laminae, when Lagos White, which had a more rapid loss of leaf by senescence, had come to a standstill. The more pronounced longevity of the photosynthetic area in ES 2 appears therefore the major determinant of the higher production of dry matter by this variety. The possible significance of variation in longevity of leaves had been pointed out already in 1929 by Boonstra, who found some evidence of an association of longevity of leaves and high yields in four varieties of oats.
The effect of time of irrigation on the growth and yield of transplanted rice plants (Oryza sativa L.)
Authors: Enyi B. A. C.
Published: March 2009

1. Continuous waterlogging and 4 weeks' waterlogging immediately after transplanting produced plants with higher leaf and shoot numbers.

2. There was no difference in the final shoot number between plants continuously waterlogged and those waterlogged for 4 weeks, immediately and 4 weeks after transplanting. The shoot mortality was higher in the continuously waterlogged plants and those waterlogged for 4 weeks immediately, 8 weeks and 12 weeks after transplanting than in those waterlogged for 4 weeks, 4 weeks after transplanting.

3. Continuously waterlogged plants and those waterlogged for 4 weeks, 4 weeks after transplanting, were taller than those waterlogged for 4 weeks, immediately, 8 weeks and 12 weeks after transplanting.

4. Leaf area per bucket, leaf area per shoot and per leaf lamina were higher in continuously waterlogged plants and those waterlogged for 4 weeks, 4 weeks after transplanting, than in those waterlogged for 4 weeks immediately, 8 weeks, and 12 weeks after transplanting.

5. Continuous waterlogging and waterlogging for 4 weeks, 4 weeks after transplanting, increased the physiological age of the plants as evidenced by earlier ear emergence and grain ripeness.

6. Fresh-weight yield, yield of grain and panicle were greater in continuously waterlogged plants and those waterlogged for 4 weeks, 4 weeks after transplanting, than in those waterlogged for 4 weeks immediately, 8 weeks and 12 weeks after transplanting.

7. The critical period for waterlogging in the cultivation of the rice variety studied is 4 weeks after transplanting and waterlogging applied during this critical period for 4 weeks favours higher yield of grain than when applied for the same period earlier or later than this period. Where water supply is limited the plants should only be waterlogged at this period and the soil kept moist throughout the remaining growing period. However, where there is enough water to waterlog the plants for 8 weeks this should be started immediately after transplanting.
The efficiency of beef production in terms of carcass-weight increase as influenced by the ration concentration and the age of steers
Authors: Luitingh H. C.
Published: March 2009

The carcass-weight increase of beef steers of various ages receiving fattening rations of different roughage: concentrate ratios was calculated by making use of the average dressing percentage of a control group slaughtered at the beginning of the experiment.

It is shown that, in terms of t.d.n./100 lb. carcass-weight increase, which is probably the more accurate measure of efficiency, the 2-year-olds were better feed converters than the calves. When the criterion was t.d.n./100 lb. live-weight increase the calves were superior. Ration B (1 concentrates: 1 roughage) was utilized most efficiently in terms of calculated carcass-weight increase, followed in a descending order by the high-concentrate ration C and the high-roughage ration (ration A).

The relationship of live-weight increase to carcass- weight increase as calculated is discussed. The proportion of live-weight gain laid down as carcass varied with age, growth rate and type of ration. This percentage variation ranged from 57% in slow-growing calves to 81% in fast-growing 3-year-olds. On the average, calves converted 61% of their live-weight gain into saleable carcass, the 2-year-olds 70·8% and the 3-year-olds 75·9%. The steers on the A (high roughage) ration converted 65·7% of live-weight gain into carcass, those on the C (high concentrate) ration 71·5% and those on the B (1 concentrate: 1 roughage) 69·2%. Reasons for these differences are discussed in terms of so-called differential growth.

The live weights and carcass weights of steers were plotted and the regression equation

whereYis carcass weight andXis live weight, was derived. The correlation coefficientr= 0·98 and the slope of the curve indicated that for an increase of 1% in the live weight of the steers, the carcass weight increased by 1·13%.

Several methods of expressing ‘efficiency of the fattening’ were applied to the data and the results are discussed. The methods were unanimous in selecting the steers on the B ration as the most efficient followed by those on ration C and the poorest were those on the A ration. Methods based on live-weight increase showed the calves, but those based on carcass-weight increase the 2-yearolds, as the most efficient. Results obtained by applying the Efficiency Quotient and Efficiency Index suggested that the older animals wero the more efficient. They differed from all other methods since these indicated that efficiency declined with age.

Efficiency values calculated by different formulae vary and no efficiency index has yet been evolved that will embrace all the variable factors which may have an influence on the efficiency of growth and fattening.
The effect of dietary restriction on some liver constituents of sheep during late pregnancy and early lactation
Authors: Ford E. J. H.
Published: March 2009

There has been much speculation on the underlying mechanism of pregnancy toxaemia in the ewe (e.g. Reber, 1957; Kronfeld, 1958) and it is generally thought that the condition is a consequence of the failure of the ewe's metabolism to adapt to the increasing hexose demands of the foetus. Insufficient hexose is considered to be produced from dietary propionate and from the deamination of amino acids, with the result that liver glycogen is exhausted, citric acid cycle components are depleted and the resulting failure to oxidize activated acetate gives rise to ketone bodies. If this were the whole sequence of events the clinical symptoms should be reversible by the administration of glucose or glucogenic substances, orally or parenterally. Unfortunately clinical experience is that the condition shows a poor response to glucose therapy and the mortality of field cases is extremely high.
The influence of dietary concentration of calcium and phosphorus on their retention in the body of the growing pig
Authors: Mudd A. J. , Smith W. C. , Armstrong D. G.
Published: March 2009

Three gilts and three castrated males weighing 23 kg live weight were given four semi-synthetic diets containing increasing amounts of Ca and P. The Ca and P contents (% dry basis) and Ca:P ratios for the four diets were A, 0·30, 0·38, 1:1·27; B, 0·58, 0·68, 1:1·17; C, 0·94, 1·13, l:l·20; D, 1·16, 1·47, 1:1·27. Each animal was slaughtered at 41 kg live weight and the whole body contents of Ca and P determined. Six pigs were slaughtered at 23 kg live weight and their bodies also analysed for Ca and P contents. Dietary concentration of Ca and P did not influence rate or efficiency of live weight gain nor carcass characteristics. Net retention of Ca and P increased with increasing dietary concentration of these elements. Analyses of isolated femurs suggested that optimal mineralization of the bone was associated with a net retention of 8·2 g Ca/kg live weight gain. The data were used to calculate a value of 32·9 mg/kg live weight/day for the endogenous loss of Ca in pigs of 23–41 kg body weight. The values have been used to compute a mineral requirement of dietary calcium which is in excellent agreement with that derived from estimates in the literature.
Some wool follicle characteristics in crossbreds between Egyptian coarse wool sheep and long and fine-wool breeds
Authors: Ragab M. T. , Marai I. F. M.
Published: March 2009

Internal and external follicle diameters of both primary and secondary follicles of Texel x Ossimi and Merino x Barki ewes were greater, at birth, than those in either respective parent breed; the density of primary follicles at birth was less in the cross-breds than in the parental breeds, for both crosses. There was a greater increase of follicle diameter with age in the Egyptian breeds, and mean follicle diameters of the crossbreds were intermediate between those of parent breeds at ages of 3–6 months and above.

Grading up Ossimi sheep with the Caucasian Merino resulted in progressive decrease of mean internal follicle diameter. The F2, with more merino blood, had a greater frequency of the smallest diameter follicles than had the F1.
Growth of cross-bred Dorset Horn lambs from East African Blackheaded Sheep
Authors: Trail J. C. M. , Sacker G. D.
Published: March 2009

The growth of ½ ⅝, and ¾ bred Dorset Horn lambs was examined in Western Uganda. These were produced by mating Dorset Horn rams with East African Blackheaded, ¼ bred Dorset and 1/2 bred Dorset females respectively.

The influence of type of birth (single or twin) was maximum at the end of the main 2-month suckling period and progressively decreased to 11 months of age. The influence of maternal age did not decline as lambs grew older. Dorset ewes, ¼ and ½-bred, had superior milking capabilities, as measured by lamb growth at 2 months of age, to indigenous ewes. Lambs, ⅝ and ¾-bred, were 26 % heavier than ½-bred lambs at 2 months of age, and as all three types grew at the same rate from 2 to 11 months, ⅝- and ¾-bred lambs retained this initial advantage.
Statistical research on the fate of dietary mineral elements in dry and lactating cows: I. Calcium
Authors: Paquay R. , Lomba F. , Lousse A. , Bienfet V.
Published: March 2009

Statistical analyses were carried out on the data obtained under strictly controlled conditions in metabolism stalls with 41 different rations fed to 127 adult non-pregnant dry cows, and with 14 other different rations fed to 35 adult non-pregnant lactating cows that had calved 2–6 months earlier and whose daily milk production ranged from 11 to 20 kg. The authors have calculated and studied the correlations between faecal and urinary calcium losses, calcium excretion in the milk, digestible calcium, and calcium balance, and the 75 other nutritive factors which were analysed for each of the 55 above-mentioned experimental diets. The results showed that calcium metabolism is regulated in the digestive tract, and the fact that the lactation calcium requirements increase at the same time as the amounts of digestible calcium and the calcium balance corroborates this statement. But except for this endogenous factor of resorption, the fate of the dietary calcium does not depend on the ingested amounts but on the nature itself of the components of the diets and their proportions in the diets. Cereals, and especially barley, have from this point of view a particular beneficial effect. These factors act on the absorption of calcium and thus directly on the balance, since the daily urinary excretion of calcium is generally small and independent. It has also been demonstrated that the balance is not inevitably negative in cows with a daily milk production of 11–20kg, and that a careful composition of the rations should enable one to equilibrate it.

The other nutritive factors do not work on calcium utilization, but a close parallel exists between digestibility, urinary excretion and balance of both calcium and magnesium.
Equipment and housing for intake and digestibility studies with large numbers of wethers
Authors: Minson D. J. , Milford R.
Published: March 2009

In many nutritional experiments with cut pasture the voluntary intake and digestibility is determined with pen-fed sheep. However, the voluntary intakes of sheep are extremely variable, the between-animal coefficient of variation varying between 13·1% and 10·5% (Blaxter, Wainman & Wilson, 1961; Minson, Harris, Raymond & Milford, 1964). Thus each pasture cut must be fed to large numbers of animals if differences between pasture species and varieties are to be detected with significance. (Heaney, Pritchard & Pigden, 1968.)
Copper sulphate and antibiotics as feed additives for early weaned pigs
Authors: Livingstone R. M. , Livingston D. M. S.
Published: March 2009

Citric acid and three antibiotic-type substances—zinc bacitracin, tylosin and formosulphathiazole—were included in dry-meal diets for early weaned pigs up to 20 kg live weight. Two experiments were carried out and in each copper sulphate as 0.1 % of the diet was tested.

In the first experiment the diets were supplemented with citric acid, copper sulphate or both citric acid and copper. The pigs given the diet containing both citric acid and copper tended to have the greatest daily live-weight gains and there was a similar trend in favour of the diet containing copper sulphate alone, but these advantages did not reach significance.

In the second experiment diets with or without copper sulphate were supplemented with either Zinc Bacitracin, Tylosin or formosulphathiazole. All three ‘antibiotics’ had beneficial effects on rates of gain and feed-conversion efficiency, resulting in average. increases of 15% and 10% respectively. Copper sulphate did not improve the performance of the pigs when included in the basal diet with or without an ‘antibiotic’ and there was no interaction between the copper supplement and any of the other supplements.

The performance of the pigs after 20 kg live weight under standard conditions showed little evidence in these experiments that the beneficial effects of feed additive use before this weight persisted during growth to 90 kg live weight or that any of the major measures of carcass quality were affected by the early treatment.
Some effects of wintering yearling beef cattle on different planes of nutrition: I. Live-weight gain, food consumption and body measurement changes during the winter period and the subsequent grazing period
Authors: Lawrence T. L. J. , Pearce J.
Published: March 2009

An experiment is described in which the growth rate and conformation changes of cattle subjected to different levels of nutrition during their yearling winter, and then re-alimentated on grass, were studied.

For this purpose thirty-six Sussex x Shorthorn steers between 38 and 52 weeks of age were randomly distributed on the basis of live weight into three groups, each of twelve animals.
Some effects of wintering yearling beef cattle on different planes of nutrition: II. Slaughter data and carcass evaluation
Authors: Lawrence T. L. J. , Pearce J.
Published: March 2009

The data on the conformation and age at slaughter, together with that on the slaughter and carcass work obtained from the thirty-six animals which had been subjected to differential winter feeding (see Part I), is presented and discussed.
The productivity of five grass species at six levels of compound fertilizer application II. Crude-protein production
Authors: Henderson J. L. , Edwards R. S. , Hammerton J. L.
Published: March 2009

1. Data on the crude-protein content and crudeprotein production of five grass species (each sown with white clover) over the period 1954–56, at six levels of compound fertilizer application, are reported. Perennial rye-grass (S. 101), meadow fescue (S. 215), timothy (S. 48), cocksfoot (S. 26) and bent (N.Z. Browntop) were sown in 1953 at appropriate seed rates, each with 2 lb./acre S. 100 white clover. The fertilizer treatments were 0, 1, 3, 5, 7 and 9 cwt./ acre of a compound of composition 10% N, 4%P2O5, 9·5% K2O applied in the early spring of each of the years 1954–56. The swards were cut three times a year in 1954 and 1956, but only two cuts were possible in 1955.

2. Bent mixtures had a higher crude-protein content than any other mixture in all years and (with one exception) at every cut within years. Differences between other mixtures were smaller and often erratic, though timothy invariably had the lowest crude-protein content at the second cut and cocksfoot at the third. Application of the fertilizer raised the crude-protein level of the herbage at the first cut, but depressed it in subsequent cuts.

3. The bent mixture gave the highest yield of crude-protein per acre followed by the timothy mixture, while the lowest yield was produced by the perennial rye-grass mixture. The bent mixture differed from all others in its distribution of crudeprotein production over the season, producing less at the first cuts and more at the second and third cuts. This reflects its pattern of production of dry-matter. Response to spring application of fertilizer in terms of crude-protein yield declined rapidly from cut to cut. Over the whole period of the experiment 1 cwt./acre/ annum of fertilizer containing 10% N gave a response of about 0·5 cwt. crude-protein/annum.
Variation in efficiency of food utilization in twin calves I. Individual variation and age trends in efficiency
Authors: Taylor C. S. , Watson J. H. , Young G. B.
Published: March 2009

Efficiency of food utilization from 2 to 18 weeks of age has been examined in 12 MZ and 7 DZ pairs of twin calves fed standard rations. Mean efficiency reached a maximum at about 6 weeks of age; weaning brought about a rapid decline followed by a recovery. Animals became more alike in efficiency as their ages increased.

Those animals least efficient shortly after birth were most adversely affected by weaning, although they tended to be relatively more efficient when fully established on either milk or solid food.

Relative to the fairly closely replicated age-efficiency trends of identical twins, different pairs followed different trends. These trends, which primarily reflected the variable success with which the calves adapted to new diets, were subject to some genetic control.
The use of hexoestrol for beef production from zebu cattle under ranch conditions in Tanganyika
Authors: Hutchison H. G. , Robb J. M.
Published: March 2009

1. Three groups of twenty, 3½ to 4-year-old zebu steers, replicated four times in each quarter of the year, were used to examine the effects of 30 and 45 mg. hexoestrol implants on their beef production, under ranch conditions in Tanganyika.

2. Significant advantages in mean live-weight gains of 20·8–47·3 lb. for 30 mg., and 9·8–47·3 lb. for 45 mg., were obtained when treated at any time of the year; but during the dry-season implantation is contra-indicated as initial response is adverse although followed by pronounced recovery when pasture conditions improve.

3. There was no significant difference between dosage rates in growth response, but on smaller steers, and as the pasture deteriorated, 45 mg. showed signs of being excessive.

4. Duration of significant response was about 3 months during the period of adequate grazing, but was delayed to 5 months, and probably longer, during the dry season.

5. Steers were slaughtered 6–9 months after implantation and at that time showed: no significant difference in dressing percentage, shrinkage in store, proportion of bone, or carcass grade; there was significantly less fat, and more lean, but increased proportion of moisture in the muscle accounted for the extra proportion of lean in the sample joints.

Treated carcasses were significantly longer by 1·0% and highly significantly larger in circumference of hind quarter by 2·0%.
Housing and equipment for balance studies with cows
Authors: Balch C. C. , Johnson V. W. , Machin C.
Published: March 2009

A description is given of a building and equipment which have proved suitable for cows in experiments involving the separate collection of faeces and urine.
Establishment studies VI. The effect of method of establishment on long-term leys in the first harvest
Authors: Charles A. H.
Published: March 2009

1. The method of establishment markedly affected the yield of red clover in the first harvest year, the highest yield being obtained when a cover crop was used, in the absence of which red clover yield was reduced by frequent grazing during establishment. White clover made little growth in the first harvest year; the yield was best without a cover crop under frequent grazing during establishment.

2. Nitrogen applied in the seed bed did not affect the growth of red clover in the first harvest year, but depressed the white clover under infrequent defoliation without a cover crop. There was no significant effect under the other management.

3. The total yield of red and white clovers was lower, when sown with the rapidly establishing ryegrass or ryegrass-dominant general-purpose mixtures, than with cocksfoot or timothy mixtures. Weed growth, although not prominent, was far greater in the timothy and cocksfoot swards than in those based on ryegrass.

4. A close parallel existed between the growth of red clover and the dry matter and yield of crude protein. The highest figures were recorded when management during establishment had favoured the growth of the red clover.

5. Nitrogen applied in the seed bed reduced the percentage of crude protein in all mixtures in the spring and autumn grazings, and in the hay crop of the first harvest year. Management which encouraged the growth of red clover increased the crude protein percentage of herbage in the spring and autumn, but depressed it in the aftermath cut.

6. A number of interactions occurred when the relative yields of dry matter and crude protein of mixtures in the first harvest year were modified by treatments applied during establishment. There are significant indications that the method of establishment is a factor to be considered in evaluating various mixtures.
Early reproductive failure of ewes in a hot environment III. The thyroid
Authors: Ryle Margaret
Published: March 2009

1. A balanced factorial experiment was carried out with 48 Merino ewes. There were two levels of each of the four factors: environmental temperature, thyroxine status, vitamin A intake and progesterone status. Each ewe was killed at 25 days' pregnancy. The thyroid was removed, weighed and examined histologically.

2. Thyroid weight in the hot-room animals was significantly decreased by large doses of vitamin A. It was not affected by any of the other treatments.

3. With respect to the number of follicles per unit area of cross-section, the following interactions were significant: temperature × vitamin A; temperature × progesterone; temperature × vitamin A × thyroxine. The directions of the effects of vitamin A and of progesterone were reversed by the higher temperature.

4. There were no significant effects on nuclear height in the follicular epithelium.

5. The frequency of marked ‘scalloping’ at the edge of the colloid was significantly higher among those ewes receiving thyroxine injections than in the remainder. This feature was not significantly affected by any other factor.
Experiments on organic manures, 1942–49
Authors: Bunting A. H.
Published: March 2009

… In short, he used many learned arguments to persuade his audience out of their senses; and from stench made a transition to filth, which he affirmed was also a mistaken idea, in as much as objects so called, were no other than certain modifications of matter, consisting of the same principles that enter into the composition of all created essences, whatever they may be: that in the filthiest production of nature a philosopher considered nothing but the earth, water, salt and air of which it was compounded.…
The effects of castration on meat production in cattle, sheep and pigs
Authors: Prescott J. H. D. , Lamming G. E.
Published: March 2009

1. The influence of castration on meat production has been studied in three experiments involving cattle, sheep and pigs. The results are presented to indicate the changes which might be expected in more extensive experiments, and give an indication of the parameters likely to be important.
Effects of a high level of nitrogenous fertilizer and date of cutting on the availability of the magnesium and calcium of herbage to sheep
Authors: L'Estrange J. L. , Owen J. B. , Wilman D.
Published: March 2009

1. Herbage harvested from 17 April to 3 July, at approximately 3 weeks after defoliation, from a succession of high-nitrogen paddocks (1001b. nitrogen in March and 60 lb. nitrogen at monthly intervals thereafter, all as Nitro-chalk) and from corresponding low-nitrogen paddocks (40 lb. nitrogen as Nitro-chalk in early March only) was fed to two wethers, and the availability of magnesium and calcium were measured in a series of balance trials.
Factors affecting the gestation length in sheep
Authors: Forbes J. M.
Published: March 2009

The data from 555 normal pregnancies during a period of 6 years in a flock of Scottish Half bred ewes were examined for relationships between gestation length and litter size, birth weight, sex, and age of ewe. A' comparison of Scottish Half bred gestation lengths was also made with those of Specklefaced Welsh ewes.
The influence of dietary calcium and phosphorus concentration on their absorption in the cow
Authors: Manston R.
Published: March 2009

Experiments were carried out in dry, nonpregnant cows by varying dietary concentrations of calcium and phosphorus. Calcium and phosphorus absorption were measured by balance and isotope techniques. It was found that absorption of calcium or phosphorus increased when the dietary intake of the element increased, but only for a few days.
Walking trials with cattle II. A comparison of bulls, steers and heifers
Authors: Murray D. M. , Yeates N. T. M.
Published: March 2009

1. The heat tolerance and walking performance of bulls, steers and heifers exposed to moderate heat stress have been compared, following the method of Yeates & Murray (1966). Hereford cattle aged 14–16 months were used in the experiment. Two speeds of walking were employed and the effect of clipping the coats of both exercised and stationary cattle was studied.

2. In the undipped state, at both speeds of exercise (1⅔ and 2⅔ m.p.h.), the heifers performed best followed by the steers and bulls in that order, judged by their ability to preserve normal body temperature.
Lack of response by growing-finishing pigs to germicidal ultraviolet radiation
Authors: Morrison S. R. , Hintz H. F. , Givens R. L.
Published: March 2009

Three tests—two winter and one summer—involving 134 growing-finishing pigs showed no response to germicidal ultraviolet radiation. The pigs received no direct sunlight and were irradiated nearly continuously for periods of 54–70 days. Lamps with a 2537 Å output of 5·2 W were provided at rates of one lamp per 11·1 m2 in two tests and one lamp per 3·35 m2 in one test.
Studies on the Hyparrhenia veld:VI. The fertilizer value of cattle excreta
Authors: Smith C. A.
Published: March 2009

A plot trial tested the fertilizer value of dung and urine evenly spread on Hyparrhenia veld which was very deficient in N and was also deficient, although less seriously, in P.
A study of the effect of supplementing a concentrate diet with roughages of different quality on the performance of Friesian steers. I. Voluntary food intake and food utilization
Authors: McCullough T. A.
Published: March 2009

Concentrate diets supplemented with 5, 20 and 40% of a high- and a low-quality hay were given ad libitum to British Friesian steers from 9 weeks of age to slaughter. The intake of dry matter and metabolizable energy was studied over weight ranges from 91 to 363 kg live weight. The quality of hay did not significantly affect the drymatter intake at any of the weight ranges studied. From 91 to 182 kg live weight the daily dry-matter intake decreased as the proportion of hay in the diet increased. Over the weight range from 182 to 272 kg live weight, intake was maximum at the 20% level of hay supplementation, while from 272 to 363 kg live weight, intake increased with increasing levels of hay in the diet. The supplementation of high-quality hay significantly increased the intake of metabolizable energy by animals weighing 91–182 kg. Increasing proportions of hay in the diet significantly affected the metabolizable energy intake at all stages of growth studied.

At 18 and 36 weeks of age digestibility and N balance studies were carried out. The metabolizable energy expressed as a percentage of the gross energy and the mean retention time of the diets were significantly affected by the age of animal, quality of the hay and the level of hay supplementation. Nitrogen retention was also affected by the age of the animal but not by the quality of the hay.

The relationships between the voluntary intake of dry matter and the metabolizable energy of the diet expressed as a percentage of the gross energy, for different stages of growth, are also presented.

The change in the digestibility and the mean time of retention of the diets in the digestive tract with age and the effect of this on the point where physical regulation to intake gives way to physiological regulation are discussed.
Mother–offspring relationships in Awassi sheep:III. The effect of different suckling regimes and weaning age on weight gains of lambs in dairy flocks
Authors: Folman Y. , Eyal E. , Volcani R.
Published: March 2009

1. Three experiments were carried out on 112 Awassi lambs of both sexes, born as singles. During the first 8 or 9 weeks of their life they sucked an average of 78, 108, 53 and 50 kg. of milk per head for 12 hr. per day sucklings in a medium producing flock and 12 hr., 4 hr. and residual sucklings in a high producing flock, respectively.
The sources of assimilate for grain development in tall and short sorghum
Authors: Goldsworthy P. R.
Published: March 2009

The dry weight contributed to the grain yield of sorghum by different parts of the plant was measured by removing laminae and by shading the head. A Nigerian tall variety formed more dry weight after heading and had a larger leaf area duration than a short-season, hybrid sorghum, but its grain yield was smaller. Laminae contributed more than 80% of the dry weight formed after heading in the Nigerian sorghum but less than half of this went into the grain. The remainder went into the stem, mainly to replace respiratory losses, or accumulated in the rachis and branches of the head. Top, middle and bottom groups of laminae contributed 42, 22 and 12% respectively to the dry weight of the grain; the remaining 24% was contributed by the sheaths. In the short-season hybrid sorghum over 70% of the dry matter formed after heading was stored in the grain. Only about half of this came from the laminae; assimilation in the head and in the sheaths contributed about equally to the remainder.
The effect of different nitrogenous fertilizers applied as solids or soluctions dry matter yields and niotrogen uptake by grass. Part II
Authors: Nowakowski T. Z. , Newman A. C. D. , Penny A.
Published: March 2009

Three field trials with Italian ryegrass showed that solid N fertilizers usually gave larger yields than solutions containing 5% N but the differences were significant in only three of thirteen comparisons. More N was taken up from solid fertilizers than from solutions; the differences were not significant at 561b N/acre but were at 1121b N/acre. Grass given solutions had smaller percentage of N and the differences in the percentage of N were significant in eight of ten comparisons. In pot experiments with Italian ryegrass, solutions containing 3.3% N were less effective than solid fertilizers, but solutions containing 1.8% N were equally effective. Possible causes of solutions being less effective are discussed.
The nutritive value of Panicum maximum (Guinea grass): I. Yields and chemical composition related to season and herbage growth stage
Authors: Johnson W. L. , Hardison W. A. , Castillo L. S.
Published: March 2009

The results of more than fifty estimates1 of herbage yield and ninety-seven analyses of chemical composition are presented in the first of several reports on nutritive evaluation studies of Panicum maximum (guinea grass). Effects of stage of maturity and season are discussed.

Herbage yield increased at an increasing rate with maturity, and was depressed by about 40 % in the dry season compared to the wet season. The most significant differences in chemical composition were a decrease in crude protein from 9·8 % to 6·6% and a corresponding increase in crude fibre from 32·1 % to 39·4% as the grass matured from about 2½ weeks to about 2½ months in age. An increased level of nitrogen fertilization resulted in crude protein content being nearly doubled and crude fibre somewhat reduced.
The use of coarsely milled barley straw in finishing diets for young beef cattle
Authors: Forbes T. J. , Raven A. M. , Irwin J. H. D.
Published: March 2009

An experiment was carried out in which young beef cattle were given diets containing different levels of coarsely milled (1 in screen) barley straw. The proportions of straw used were 0, 10, 20, 30, 40 and 50 % and the performance of animals on these diets was compared with that of similar animals on an all concentrate diet. Each diet was given ad libitum to six animals. There was a significant linear decline in live-weight gain with increasing straw intake, the rate of decline being 0·62 ± 0·133 kg per week for each 10 % increase in the level of straw in the diet. The dry matter conversion ratio increased linearly with increasing straw intake, the rate of increase being 0·65 ± 0·186 units for each 10 % increase in straw in the diet. Dry matter intake was significantly (P < 0·001) affected by the proportion of straw in the diet. Although dry matter intake increased to a maximum at a level of 18·8% straw in the diet there was no significant increase in the intake of digestible organic matter (DOMI). There was a significant (P < 0·001) linear decline of 0·19 ± 0·04 kg DOMI with each 10% increase in straw in the diet. There was a significant linear decline in chilled carcase weight to the extent of 5·7 ± 0·096 kg for each 10% increase in straw. The killing-out percentage based on unfasted live weight declined significantly as the percentage of straw in the diet rose from 20 to 30%. However, when the killing-out percentage was calculated on the basis of live weight at slaughter less rumen contents there was no significant difference between treatments.
The estimation of plasma and red cell volumes in pigs
Authors: Anderson D. M. , McDonald I. , Elsley F. W. H.
Published: March 2009

Plasma volume, haematocrit, and haemoglobin concentration were measured in 34 sows. Red cell volume and total blood volume were calculated from plasma volume and haematocrit.

The method of back extrapolation of the logarith of Evans blue concentration to zero time possibly overestimated plasma volume. Haematocrit was found to be higher and more variable in the initial blood samples in each experiment, than in the blood samples taken 30 and 60 min later.

In animals of the same parity, plasma and red cell volumes were closely related to live weight, but the relationship varied between parities.
The concentration of minerals in the blood of genetically diverse groups of sheep: I. Copper concentration at different seasons in Blackface, Cheviot, Welsh Mountain and crossbred sheep at pasture
Authors: Wiener Gerald , Field A. C. , Wood Jean
Published: March 2009

The concentration of copper in the blood of more than 300 sheep of a grassland flock was determined on each of five occasions between May 1965 and June 1966. Six breed classes, Scottish Blackface, Cheviot and Welsh Mountain, and the three crosses among these breeds, were involved.

Breeds differed significantly in blood copper concentration with the Blackface having consistently the lowest and the Welsh the highest values. Crossbred sheep showed marked heterosis. Their levels were mostly at or near to the concentration of the parental breed with the higher value. Within breeds there was a positive regression of blood copper level on live weight of ewe.

Ewes which had produced lambs affected by swayback in 1964 had lower levels of copper in their blood than ewes which had produced normal lambs. The difference was significant and most marked in winter.

Ewes which were barren had, subsequently, higher blood copper concentrations than ewes with lambs. Ewes with single lambs had on average slightly higher levels than those with twins (but not significantly so), however, the effect differed among the breeds. Blood copper levels differed significantly on most occasions with the week in which ewes lambed in relation to the date of bleeding. Age of ewe had significant effects on copper concentration only at one bleeding (January 1966).

There was an indication that classes low in copper concentration, notably Blackfaces and mothers of swayback lambs, showed a relatively steeper decline in copper levels during the winter than did other sheep.
Flower drop and fruit set in field beans, Vicia faba L.
Authors: Kambal A. E.
Published: March 2009

The percentage of the total buds produced that dropped before reaching the mature pod stage was estimated as 86·7% in Baladi, a local strain of field beans, and 93·7% in Giza 1, a variety introduced from Egypt. The drop was appreciable both before and after fertilization. There were indications that both inadequate insect pollination and inter-ovary competition contributed to the reduction of pod yield.

Self pollen was detected on the stigma in the bud stage 2–3 days before the flower was open. Estimates of natural cross-fertilization ranged from 35·8 to 42·1%, indicating that self-pollination did not lead to complete self fertilization. Hand manipulation of the flowers increased pod set in most of the cases but the line 1W did not respond to this treatment and proved to be highly autofertile.
Morphological and physio-chemical studies on dwarf Herefords
Authors: Hafez E. S. E. , Ensminger M. E. , Ham W. E.
Published: March 2009

Thirty-six Hereford dwarfs, ‘comprest’, dwarf-like, and eight controls were available. Body and skin measurements were taken and the types of head abnormalities and cardiovascular activities were recorded. Haematological tests and chemical analysis of blood and hair were carried out.

Typical dwarfs showed characteristic head abnormalities with varying degrees either at birth or later in life, possibly as a result of different stages of development at which the defective gene(s) comes into operation. There were progressive changes (qualitative and quantitative) in the expression of dwarf characteristics. Typical dwarfs were chronic bloaters, with pot-shaped belly or with normal belly. Atypical dwarfs were either stunted, showing (miscellaneous) deleterious genes or ‘comprest’ types. The daily live-weight gain of typical dwarfs ranged from 0·71 to 1·69 with an average of 1·26 lb. (controls 1·72 lb.). Body, head, and limb indices in typical dwarfs are similar to those of the ‘comprest’ and the control animals at comparable weights. Volume index was higher in the control than in the typical dwarfs. In the bloater dwarfs the width of the body at the shoulder region was considerably narrower. Skins of the typical dwarfs were thinner. The bloater dwarfs showed a diurnal bloat cycle (in relation to feeding time) as judged by body circumference. The severity of bloat was irregular.

There was no significant difference between typical dwarfs and control animals in rectal temperature, pulse rate, blood, specific gravity, prothrombin time, sedimentation rate, red cell count, electrophoretic pattern of serum proteins, serum creatine and creatinine and calcium/phosphorus ratio in hair samples. Typical dwarfs had slower respiration rate, lower blood haemoglobin, haematocrit, and white blood count than did the controls. Post-mortem examination of dwarfs did not show similar causes of death in each case. The heart of the dwarfs was spheroid, showing severe dilation in most cases.
The errors of long-term experiments
Authors: Patterson H.D , Lowe Bridger I.
Published: March 2009

Yield (or other variate) values from crops recurring on the same plots in long-term experiments are subject to correlations known as serial plot correlations. Neglect of these plot correlations can result in loss of efficiency in the estimation of treatment effects and bias in the estimation of error.

Serial plot correlations are calculated from 12 experiments on arable crops in England and Wales, for yields 4, 6 or 8 years apart. They are usually positive, with average value 0·2. In one set of experiments the losses in efficiency caused by plot correlations of this magnitude are shown to be small, but some of the biases in the estimates of error are large. Biases in the variances of treatment means can be wholly or partly eliminated by separating two components of error, plot error and plot x year error.
Protein concentrations in colostra from Finnish Landrace × Scottish Blackface ewes during the first week of lactation and in sera from the ewes and their lambs on the third day of lactation
Authors: Halliday R.
Published: March 2009

Twenty-six Finnish Landrace × Scottish Blackface ewes, mated to a Dorset Horn ram, produced 58 lambs. Protein concentrations in the ewes' colostra during the first week of lactation, and in the ewes' and lambs' sera on the 3rd day after parturition were compared with those in pure-bred Finnish and Blackface sheep. In cross-bred and Blackface lambs the total serum protein and γ-globulin concentrations decreased significantly as litter-size increased. Litter-size had much less effect in Finnish lambs. When litters of the same size were compared, cross-bred lambs tended to have higher concentrations than Blackface lambs, but had much lower concentrations than Finnish lambs. The mean protein concentrations in sera and presuckling colostra from Finnish × Blackface ewes were almost exactly the same as in Finnish ewes, but were considerably lower and higher, respectively, than in Blackface ewes. When suckling began the concentrations in the colostra decreased much faster in Finnish ewes, even when ewes nursing the same number of lambs were compared. Differences in suckling behaviour on the day of birth may therefore partly account for the variations in the amounts of maternal protein obtained by lambs of different breeds.
Use of the quantity/potential relationship to provide a scale of the ability of extractants to remove soil potassium
Authors: Addiscott T. M.
Published: March 2009

Quantity/potential relationships, between gain and loss of K by the soil and K potential (RT In ακ/⊧αca+Mg) were determined on twenty-seven Rothamsted and Woburn soils. K extracted by neutral N ammonium acetate, by H-resin and 0·5 M sodium bicarbonate (pH 8·5) were also measured.

The ability of an extractant to remove soil K is equated to a K potential (derived from the quantity/potential curve) which the soil attains on removing K equal to that taken out by extractant. Mean values for all soils were – 4995 ± 97 cal/equiv for the ammonium acetate, – 6081 ± 88 cal/equiv for the H-resin and – 4336 ±117 cal/equiv for the sodium bicarbonate extractants. For the first and last extractants the ability to remove K was less in rich than in poor soils.

Varying the ammonium ion concentration from 0·1 N to 1 N in ammonium acetate/acetic acid mixtures, N in acetate ions, did not greatly affect their ability to remove K.