bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparisons of casein and formalized casein with ammonium sulphate, calcium nitrate and urea for Italian ryegrass
Authors: Widdowson F. V. , Shaw K.
Published: March 2009

1. Italian ryegrass, laid down for two years, was used to compare the value of casein and formalized casein, ammonium sulphate, calcium nitrate and urea for grassland production. Residual effects of these treatments were measured on a third-year crop of barley.

2. Single dressings of ammonium sulphate and casein were of similar value at each of three cuttings in 1956.

3. Casein treated with formalin released nitrogen much more slowly and was of little value in the early part of the growing season. Formalized casein produced significantly higher yields than casein at the later cuttings in both years, but aggregate increases from this material were much lower than those obtained from untreated casein in each season. Formalized casein increased yields considerably in the year following application.

4. Single dressings of formalized casein were also compared with ‘repeated’ dressings of ammonium sulphate, calcium nitrate and urea, in which the same total quantity of nitrogen was divided equally between cuttings. Formalized casein produced much lower yields than these ‘repeated’ dressings in the early part of the season, but was of only slightly less value at the last cut in 1956 and gave the highest yield at the final cut in 1957. Aggregate yields from repeated dressings of inorganic N fertilizers were higher than those given by single dressings of either form of casein.

5. Comparisons were also made between the yields given by ammonium sulphate, calcium nitrate and urea. Urea applied before sowing (at 0·5 cwt. N/acre) damaged germination and reduced plant establishment slightly. Under dry conditions both urea and calcium nitrate tended to give higher yields than ammonium sulphate but with adequate rain all three fertilizers gave similar yields.
The skin characters of some breeds of indigenous African cattle
Authors: Walker C. A.
Published: March 2009

The present work extends the information on the skin thickness of cattle and shows that generalizations made in previous work were only partly correct, for there are significant differences only between the skin thickness of the Zebu ‘races’ of tropical cattle and Bos taurus.

Again there appeared to be no significant difference between animals of different ages within breeds.

The work confirmed that cattle of eleven tropical breeds comprising four of the major ‘races’ of African indigenous cattle have a significantly thinner papillary layer than temperate breeds, and this was very strongly correlated with their superior heat toleration.

Further support based on wider premises was therefore given to suggestions made by Dowling regarding the importance of the histology of the skin in heat toleration.
The population, morphology and evolutionary trends of the apocrine glands of African indigenous cattle
Authors: Walker C. A.
Published: March 2009

An examination of the population density and morphology of the apocrine glands of four ‘races’ including fourteen breeds of African indigenous cattle has been completed.

Two types of gland were found, the club-shaped and the sac-like, and it is suggested that the former is the more primitive form.

Considerable differences in gland density and volume were found. In the thoracic-humped African Zebu both of these were similar to figures given for B. indicus sui generis.

Gland volume was found to be closely correlated to heat toleration, but it is suggested that secretory rate is probably of high importance in view of the fact that despite differences in gland volume, there were only small differences in heat toleration coefficient.

It is suggested that the heat toleration coefficient as presently defined may not be a reliable indication of the animals tolerance of prolonged high temperatures.

A suggestion is made regarding the mechanism of heat control by sweating in cattle.
The effect of sulphate of ammonia applications on the sulphur content of various grass and clover mixtures
Authors: Jones D. J. C.
Published: March 2009

1. The effects of annual applications of 0–12 cwt. per acre of sulphate of ammonia on the herbage levels and yields of sulphate sulphur and total sulphur were investigated in four seeds mixtures 1 year and 4 years after seeding down.

2. There were significant increases in the levels and yields of both forms of sulphur up to the 2 or 4 cwt. per acre level of application in both years. The maximum values occurred at the 6 or 8 cwt. level and the corresponding values at the 12 cwt. per acre rate of application declined in many cases.

3. The cumulative effects of the annual dressings of sulphate of ammonia resulted in substantial increases of approximately 50% in the levels of sulphate sulphur and total sulphur with much smaller increases in the levels of non-sulphate sulphur.

4. Duplicate plots which received 2, 4 and 6 cwt. per acre of sulphate of ammonia also received an additional 2 cwt. per acre immediately after the first cut each year. This splitting of the dressings had no significant effect on the accumulation of sulphur by any seeds mixture. A second cut from the cocksfoot plots in the first year showed the sulphur levels in the plots which received the additional sulphate of ammonia to have increased less than the levels in those which received only the initial dressing. This was explained in terms of the yields of the components.

5. There was a tendency for the rye-grass mixture to contain more sulphate than the other mixtures particularly in the fourth year.

6. The possible significance of the increases found in sulphate levels in the copper-molybdenum metabolism of grazing animals is discussed.
The age of queen honeybees and the tendency of their colonies to swarm
Authors: Simpson J.
Published: March 2009

Swarm preparations are leas frequent (at least during July and August in southern England) among colonies with queens reared in the current year than among those with queens of the previous year (Simpson, 1957). Queens which had survived one and two winters are now considered; they are described as 1- and 2-year-old, respectively.
The effect of adding lysine and methionine to the diet of pigs kept on low-protein vegetable foods
Authors: Evans R. E.
Published: March 2009

The beneficial effect on the nutritive value of bread and similar cereals of adding small amounts of lysine and other essential amino acids has recently aroused considerable interest both in Great Britain and in America. Tests carried out with rats have shown considerably improved growth rates accompanied by increased efficiency of food conversion.
Studies on the production of beef from zebu cattle in East Africa II. Milk production in suckled cows and its effect on calf growth
Authors: Lampkin K. , Lampkin G. H.
Published: March 2009

1. The estimation of milk yield in a herd of suckled zebu cattle has been described.

2. Milk yield was found to be relatively stable when compared with weight at calving and subsequent live-weight change.

3. Under constant conditions, there was a negative correlation between milk yield and live-weight change in the cows, compared with a positive correlation when both characters were affected by seasonal changes.

4. Variation in milk yield was reflected in the growth rate of the calves, but considerably greater quantities of milk were required to increase growth without the aid of extra grass.

5. It was concluded that, under the present conditions, calf growth rate could be increased more efficiently by the improvement of nutrition than by selection for high milk yield in the dams.
Fission products and the dairy cow III. Transfer of 131iodine to milk following single and daily dosing
Authors: Garner R. J. , Sansom B. F. , Jones H. G.
Published: March 2009

1. The transfer of 131I to milk has been studied in dairy cows following oral administration of carrierfree material in single doses as sodium iodide or as elementary iodine and in daily doses as sodium iodide.

2. The total recovery from milk during the 6 days following administration of a single dose in twentyeight experiments on fifteen animals ranged from 1·3 to 19·4% of the dose with a mean value of 5·5%. The variations in recovery can be attributed largely to differences in the milk yield.

3. There was no significant difference in the biological availability of 131I administered as iodide or iodine.

4. The change in concentration of 131I in milk with time following daily dosing did not follow the predicted course, a peak value being observed in most animals after 1–3 days, followed by a fall and a subsequent rise to a steady value lower than was expected.

5. The presence of a concentrating mechanism in the udder has been demonstrated by administration of sodium thiocyanate. Comparison of the milk total 131I: plasma dialysable 131I ratio at different times of the year indicates that the concentrating ability may be lower in the summer than in the autumn-spring months.
Effect of castration and dietary protein level on growth and carcass composition in beef cattle
Authors: Robertson I. S. , Paver H. , Wilson J. C.
Published: March 2009

Thirty-six Hereford cross Friesian calves weighing on average 82.4 kg at an average age of 90 days were allotted in randomized blocks to a 2 x 3 factorial design. Castration by the open method was performed on half the number of calves and three dietary crude protein levels, 20, 14 and 11 % in dry matter were used in a mainly cereal concentrate diet fed ad libitum individually to the animals in stalls. Slaughter was at a fixed weight of approximately 420 kg.

Steers compared with bulls gained weight at a significantly slower rate and with less efficiency. Castration's greatest effect in reducing rate of gain occurred during the later stages of rearing when puberty in the bulls, as measured by a steep rise in seminal fructose, was associated with their relatively well maintained live-weight gain. The influence of testicular hormones was also apparent in the bull's carcass with its heavier head, horn and hide and significantly higher proportion of lean and lower proportion of fat in the side.

Dietary protein level affected rate of gain in both bulls and steers but at each level bulls performed better than steers. With circumstances similar to those in this experiment, a 14 % crude protein level in concentrate dry matter appears adequate for both categories up to a live weight of circa 270 kg and a reduction to 11 % thereafter. The effect of protein level on tissue proportions of the side and carcass composition generally was minimal.
Studies on the adaptability of three breeds of sheep to a tropical environment modified by altitude II. Responses in body, skin and coat temperatures, cardio-respiratory frequencies and rate of moisture secretion of ewes to the diurnal fluctuation in ambient temperature during the hottest part of the year
Authors: Symington R. B.
Published: March 2009

Responses in body, skin and coat temperatures, cardio-respiratory frequencies and rate of moisture secretion of ewes of three breeds to the diurnal fluctuation in ambient temperature were recorded in the presence and absence of drinking water during the hottest part of the Rhodesian year.

1. At 7.0 a.m. body temperatures were: Merino 102·8° F.; Persian 102·2° F. and Native 101·5° F. Between 7·0 a.m. and 1·0 p.m. body temperature rose almost equally in Persians and Natives and fell slightly in Merinos. Change in body temperature between 7.0 a.m. and 1.0 p.m. was not affected significantly by availability of water nor age of ewe, but varied with type of thermal burden (i.e. solar insolation only v. solar insolation plus artificial heat) when water was not available. Although air temperature fell towards late afternoon body temperature of Merinos and Natives rose appreciably, that of Persians only slightly.

2. At 7·0 a.m. respiratory rates were (cyc./min.): Merino 59·6; Persian 43·0; Native 29·9. Increase in rate of respiration was the main thermolytic mechanism in all breeds. Merinos had a lower threshold of respiratory response to rising ambient temperature than either hair breed but increase in rate of respiration between 7.0 a.m. and 1.0 p.m. did not differ significantly with breed or age.

3. No breed appeared to use the peripheral blood system in thermoregulation. Cardio-frequency, as a measure of this blood flow, remained almost constant with a slight tendency to fall with rise in ambient temperature.

4. In all breeds skin temperature was related to ambient and body temperatures; consequently the diurnal fluctuation in skin temperature differed in wool and hair breeds. When thermal burden was greatest Merino skin temperature fell, that of hair breeds did not.

Except at 11.0 a.m. there was a gradient between rectal, skin and air temperatures. Direct elimination of heat was thus possible for 23 hr. each day.

5. In hair breeds moisture secretion depended on insensible perspiration; consequently, rate of moisture secretion changed with body and air temperatures. In Merinos moisture for skin surface evaporation was provided by sensible and insensible perspiration. Natives may be able to sweat at temperatures higher than those recorded but it is unlikely Persians have a sweating mechanism.

6. In all breeds coat temperature was related closely to ambient temperature and changes in solar conditions evoked immediate response in coat temperature. Merino fleece apparently stabilized skin temperature whereas Persian and Native hair did not.
Studies on the adaptability of three breeds of sheep to a tropical environment modified by altitude IV. Role of the fleece in thermoregulation in German Merino ewes
Authors: Symington R. B.
Published: March 2009

The influence of fleece on thermoregulation in German Merino ewes was investigated in Rhodesia. Comparative heat tolerances of Persian Blackhead, indigenous Native and shorn and unshorn Merino ewes were obtained during the hottest month of the year in Northern Rhodesia. The main thermolytic responses in unshorn, partially shorn and completely shorn Merino ewes were measured at 7.0 a.m.; 10.0 a.m.; 1.0 p.m. and 4.0 p.m. during April in Southern Rhodesia.

1. Unshorn Merino ewes showed more and shorn Merino ewes less effective body temperature regulation than Persian or Native ewes. High heat tolerance in unshorn Merinos was due primarily to insulation by the fleece and not to more efficient physiological thermolysis than in hair breeds. No ewe showed signs of undue thermal stress and feed intake was not affected by heat.

2. Increases in rectal temperature and respiratory rate between 7.0 a.m. and 1.0 p.m. of Merinos in Southern Rhodesia were related inversely to fleece length. Body temperature did not differ significantly at 1.0 p.m. owing to differential rates of increase in respiratory rate.

3. Magnitude of the diurnal fluctuation in skin temperature was also related inversely to fleece length. Partially shorn ewes, however, began with and maintained highest skin temperature through the heat of the day. In all groups skin temperature fell after 10.0 a.m. although ambient temperature continued to rise. This fall could not be attributed to sweating since moisture secretion declined simultaneously.
The apparent digestibility of the non-nitrogenous components of ruminant feeds
Authors: Glover J. , Dougall H. W.
Published: March 2009

The digestibility of the non-protein constituents (almost entirely carbohydrate) of ruminant fodders is shown to be a function of the level of the crudefibre and crude-protein components.

The effect of increasing crude fibre in the diet is to depress the digestibility of carbohydrate, irrespective of the level of crude protein associated with it.

The effect of crude protein on the digestibility of carbohydrate is only well marked when its concentration in the dry feed lies below some 5%, that is when the feed is below approximate maintenance levels. Increasing the crude-protein content of the diet from some 2 to about 5% leads to increased digestibility of carbohydrate, but thereafter in the range of some 6–30% crude protein the protein effect is very slightly depressing to carbohydrate digestibility and is apparently quite negligible at average crude-fibre concentrations to be expected at any given level of crude protein.

The implications of the various aspects of this paper are that the variability in digestibility of the non-nitrogenous component of ruminant feeds depends mainly on the respective levels of crude protein and crude fibre in the diet and to a very much lesser extent, if at all, on the species of ruminant or class of feed, be it silage, roughage or even mixture.
The total digestible nutrients and gross digestible energy of ruminant feeds
Authors: Glover J. , Duthie D. W. , Dougall H. W.
Published: March 2009

It is shown that reasonable estimates of the average amounts of total digestible nutrients and gross digestible energy of ruminant feeds can be derived from knowledge of only the crude-protein and crude-fibre contents of such material as fed. These estimates do not appear to be markedly affected, if at all, by differences in class of feed or species of ruminant whether cattle, sheep or goat.

A table of the average estimates of digestible crude protein and total digestible nutrients, to be expected at different levels of crude protein and crude fibre, is presented for use in the estimation of the average nutritive value of feeds whose digestibility has not been studied in detail by means of numerous animal trials.

Inherent in the relationship between either total digestible nutrients or gross digestible energy and the proximate partial composition of the feed is a suggestion that if a low plane of protein nutrition is prolonged, that is when the crude protein of the dry diet lies persistently below some 5% in the dry feed, there is likely to be a sharp fall in the total digestibility of the feed.
Different methods for determining leaf area of some oil crops
Authors: Nur Idris Mohmed
Published: March 2009

Studies of leaf area estimate of some oil crops were made using planimeter measurement, punch borer and length × width × factor. The extent of sample variation depended on the variety in each of these methods; the last two methods were found to be simple, precise and less time consuming.
Exogenous progesterone and oestrous cycle length in the ewe
Authors: Thwaites C. J.
Published: March 2009

One hundred and sixty mature Merino ewes were randomly allocated to a factorial experiment designed to investigate the effects of short-term progesterone administration on oestrous cycle length. Groups of ewes received a series of four daily injections of 0, 10, 25 or 40 mg progesterone in peanut oil beginning either on the day of oestrus (day 0) or the next day. Equal numbers of ewes (ten per group) received subcutaneous and intramuscular injections, and those in the control groups received injections of the vehicle only.

Oestrous cycle length was significantly reduced in all progesterone-treated groups, but a consistent trend for this reduction to be greatest in ewes treated first on day 0 gave rise to a significant ‘day x dose’ interaction (P < 0·001). Route of progesterone administration had no significant effect on subsequent cycle length which, in control ewes, averaged 17·2 ± 0·1 days. For ewes first treated on days 0 and 1, mean oestrous cycle lengths for groups receiving 0, 10, 25 and 40 mg of progesterone per day were 17·3, 14·6, 12·1 and 10·7 days and 17·1, 15·2, 13·6 and 13·0 days respectively.
Environmental factors affecting persistency of lactation in Egyptian buffaloes
Authors: Asker A. A. , Bedeir L. H.
Published: March 2009

A statistical analysis was undertaken to study persistency of lactation in buffaloes, using the milk records collected on a herd of buffaloes belonging to the Ministry of Agriculture at Sakha Experiment Station. The number of buffaloes included in this report was 328 animals having 722 lactations. A formula was developed for estimating persistency of lactation in buffaloes and results obtained are as follows.
An evaluation of the properties of soil potassium influencing its supply by diffusion to plant roots in soil
Authors: Bagshaw R. , Vaidyanathan L. V. , Nye P. H.
Published: March 2009

K+ uptakes from forty-four arable soils from England by 1 cm portions of the roots of intact onion seedlings during 10 days growth were measured. A single-split-root arrangement was used, enabling the determination of uptake by known surface area of the root. Transpiration was restricted to make K+ diffusion in the soil the predominant supply mechanism. These were compared with calculated values using separately determined K+ diffusion coefficients in the soils.

Two methods were followed, namely (a) measuring K+ diffusion to a hydrogen form of cation exchange resin paper and calculating diffusion coefficients assuming total depletion of the (ammonium acetate) exchangeable K+ at the resin paper: soil boundary; and (b) deriving diffusion coefficients from estimated values of the impedance factor and the measured K+ buffer power of each soil, for 50, 60, 90 and 100% depletion of the initial soil solution K+at the root:soil boundary. None of the predictions adequately accounted for the observed uptake. Calculations of the root:soil boundary concentrations showed a wide range of depletion. Soils with initial soil solution K+ in the range 0.04–0.4 μmoles/ml were depleted of the solution K+ to near zero or even less. A negative concentration of K+ in solution indicates the probable contribution of non-exchangeable K+. When the initial soil solution K+ was more than 0.4 μmoles/ml, the uptake of K+ could be accounted for by 30–85 % depletion at the root:soil boundary.

Partial and multiple regression of the measured uptake on the initial exchangeable K+ content and the initial soil solution K+ concentration were calculated. A simple relationship between the uptake and the exchangeable K+ content accounted for about three-quarters the variance. The uptake was less closely associated with the K+ in solution or its ratio to Ca2+ + Mg2+ in solution. These correlations are discussed from the diffusion point of view and in relation to the usually reported correlations from pot experiments.

Potato yield response to K+ fertilizer additions in field experiments are examined in relation to the supply of K+ by diffusion in the soils. When K+ uptake by 1 cm portion of onion root from the unfertilized soil exceeded l.2 μmoles/10 days, yield response to K+ addition became erratic and occasionally negative.
Effects on barley and kale of NPK fertilizers containing differing proportions of urea and ammonium nitrate, and either triple superphosphate or mono-urea phosphate
Authors: Widdowson F. V. , Penny A.
Published: March 2009

Of eight experimental fertilizers (with %N; %P2O5; %K2O ratios of 2:1:1) obtained, four contained triple superphosphate and four mono-urea phosphate; all contained muriate of potash. In the first four, urea supplied either 100, 66, 33 or 0% of the total N (ammonium nitrate supplied the remainder); in the second four, urea and ammonium nitrate supplied only the balance of the N, but in the same proportions.

For barley, each fertilizer was combine-drilled to give 0·5 or 1·0 cwt N/acre. In 1965, much rain fell after drilling, early growth was not harmed and yields from each fertilizer were the same. In 1966, dry weather followed sowing and all fertilizers checked growth; those containing urea killed many plants and diminished yields. Also, yields from the fertilizers containing urea phosphate were larger than from those containing superphosphate; thus urea phosphate was safer than urea alone. For kale, the fertilizers were broadcast in May to give 1·25 or 2·50 cwt N/acre. None seriously diminished plant number and yields from all were similar.

Increasing the proportion of urea in the fertilizers greatly increased %N in the barley grain in 1966, but not in 1965. The crops recovered more N from ammonium nitrate than from urea.
The lactation of Persian Blackhead ewes and the growth of lambs: The effect of three different nutritional regimes during gestation on subsequent growth
Authors: Butterworth M. H. , Blore T. W. D.
Published: March 2009

Forty-two Persian Blackhead ewes were used to investigate the effect of three prenatal planes of nutrition 6 weeks before lambing on birth weights and weights at 4 and 12 weeks after birth of their progeny. Nutritional regimes were: good grazing with concentrate supplement (high), good grazing without supplement (medium) and poor grazing without supplement (low). Pastures used were rotationally grazed Pangola grass. High-plane ewes gained significantly more weight during the last 6 weeks of gestation than ewes of the other two groups. Ewes nursing twin lambs lost significantly more weight than ewes nursing singles during the first 4 weeks of lactation. Birth weights of male single lambs and lambs from mature ewes were significantly affected by the prenatal plane of nutrition of the ewe. Lambs from mature ewes weighed significantly more than lambs from maiden ewes and male lambs weighed significantly more than females. Live-weight gains to 4 weeks were significantly affected by prenatal plane of nutrition in all cases. Type of birth was an important factor affecting growth rate and maturity of the ewe less so. Male lambs gained more weight than females during this period. Similar tendencies were apparent during the growth period of 4–12 weeks after birth although rate of gain was lower.
Infertile bulls versus steers: II. Feed conversion efficiency and the effects of a high fat diet
Authors: Price M. A. , Yeates N. T. M.
Published: March 2009

The feed conversion efficiency of four intensively fed, partially castrated male cattle, measured over an 11-week period from approximately 9-months of age, was found to be significantly higher (P <0·05) than that of four steers.

The effect of adding 5% beef tallow to the diet during this period was also studied. Although no statistically significant result of this on feed conversion was obtained, there was an indication that fat in the diet improved the bulls' efficiency, but not that of the steers. Added dietary fat had an effect on carcass composition, increasing signifioantly (P < 0·05) the deposition of carcass fat by steers but having no such effect in bulls. It appears, therefore, that the two sex types metabolized the added dietary fat differently, the steers converting much of it to depot fat; the bulls using it (with some evidenoe of greater efficiency) for growth of non-adipose carcass components.
Physiological and economic feasibility of hormonally induced ovulation in lactating Large White sows
Authors: Epstein H. , Kadmon S.
Published: March 2009

Eighty-nine lactating sows, which had farrowed at least once before, were given 140 injections with 2000, 1800 or 1500 i.u. pregnant mare serum hormone. Seventy sows served as controls. 124 injections with 2000 i.u. P.M.S. were followed by 113 oestrus reactions and 88 pregnancies, and 16 injections with 1800 or 1500 i.u. by eleven instances of oestrus and six of pregnancy.

Oestrus occurred in 69% of the positive reactors on the 5th day after injection, and in the rest either earlier or later. The interval between the P.M.S. injection and the onset of oestrus was similar to that between weaning and oestrus in the controls.

The difference between the pregnancy rate of 71% following injection with 2000 i.u. P.M.S. and that of 83% in the control sows from the first oestrus after weaning was found to be statistically highly significant.

Mean litter size and weight were not affected by different time intervals between farrowing and P.M.S. injection, nor were there any statistically significant differences in size and weight of litters at birth or at weaning at 8 weeks of age between those of hormonally treated sowsand the controls.

The shortening of the farrowing interval by P.M.S. injection had no after-effect on the sizeand weight of litters subsequently obtained with or without hormone application.

Injections with 1800 or 1500 i.u. P.M.S. were followed by a reduced pregnancy rate, but the few litters thus obtained were similar in mean size and weight to those obtained with 2000 i.u.or those of the controls.

Sows that did not come on heat or become pregnant following P.M.S. injection came into heat at the same times after weaning of their litters as the control sows.

The shortening of the farrowing interval by an average of 22 days was considered to be of sufficiently high economic value to warrant the introduction on the farm where the experiment wasconducted of the routine application of 2000 i.u. P.M.S. to all gilts and sows on the 28th day after farrowing.
Relationships of yields of maize and cotton, and their response to phosphate fertilizer, with soil phosphate potentials in Tanzania
Authors: Addiscott T. M.
Published: March 2009

Yields of maize and cotton given N, and sometimes K but no P, were related to equilibrium values of the monocalcium phosphate potential (½pCa+pH2PO4)eq', at which P is neither lost nor gained by the soil. The responses to phosphate fertilizer were not clearly related to phosphate potentials though small responses at large values of (½pCa+pH2PO4)eq were sometimes explained by very small values of δI/δQ (the rate of change of ½pCa+pH2PO4with change in the amount of P on the soil) or by soil reaction. In only one set of maize experiments, response to P was related to δI/δQ. (½pCa+pH2PO4)0 and (pH2PO4)0', determined without adding P to the solution, were equally useful and both were just as well related to yields without P as (½pCa+pH2PO4)eq' (pH2PO4)0 appeared more useful than the logarithm of the total P concentration measured without added P. It wa not necessary to find the equilibrium phosphate potential, or to measure Ca concentration, but correcting the phosphate concentration for pH (so that only H2PO4-ions were taken into account)was worth while.
Prediction of body compostion of sheep from tritiated water space and body weight—tests of published equations
Authors: Searle T. W.
Published: March 2009

The body composition of parasite-infected sheep and of healthy sheep of various body weights and breeding was predicted from tritiated water (TOH) space and body weight using previously published regression equations. Results agreed well with body composition determined by analysis of the minced carcass though a small bias existed in some groups. It is concluded that the equations have a general application to the prediction of body composition in sheep.
The effect of seedling disturbance on the growth habit and yield of swedes
Authors: Lang R. W. , Holmes J. C.
Published: March 2009

The effect of seedling disturbance on the yield and growth habit of swedes was studied in ten experiments during the period 1960–3. Seedling disturbance consisted of the removal of soil from around the seedlings during singling, thus exposing the hypocotyl and leaving the seedlings prostrate.

Plant numbers were reduced slightly by seedling disturbance in half the experiments but not sufficiently to be a source of yield loss at the populations attained.

Seedling disturbance greatly increased the incidence of prostrate growth in swede varieties of intermediate shape, such as Victory. Two globe-shaped varieties, Bangholm and Pentland Harvester, grew erect irrespective of singling technique.

Disturbance of seedlings reduced yield when it increased the number of prostrategrowing plants. The yield depression ranged from 0·2 to 5·2 cwt D.M./acre.
Effects of nitrogen fertilizer, plant population and irrigation on sugar beet: III. Water consumption
Authors: Draycott A. P. , Durrant M. J.
Published: March 2009

A neutron moderation meter was used to measure soil moisture 0–4 feet deep in plots of sugar beet carrying two plant populations (8800 and 54000 plants/acre), each with and without irrigation. Recordings began in April or May in each of three years (1967–9) after sowing the crop and continued at 1 or 2-;week intervals until harvest in October.

The measured soil moisture deficits were very similar to potential deficits calculated from meteorological measurements. This indicates that the crop could extract the water needed for transpiration from the soil even when the deficits were quite large (more than 5 in in 1967), which probably explains the small response to irrigation by sugar beet in England.

When the soil moisture deficit increased rapidly early during the season (1967), the crop extracted water from the soil by exhausting the available water from progressively deeper horizons, whereas when the deficit increased rapidly late during the season (1969) water was still being extracted from all horizons until harvest. Both decreasing the plant population and irrigating decreased the amount of water used from depth in the profile every year.

The total amount of water used (evaporation plus transpiration), on average, from soil reserves and rainfall, was 12·2 in by the small population and 13·4 in by the large population. When irrigated, the consumption increased to 14·2 and 15·4 in. respectively. The difference in usage between populations was almost entirely from the difference in leaf cover early during the season. The water consumption in 1968, when the summer was wet, was only two-thirds of that in 1967 and 1969 when the summers were drier.
The relationship between the yields of eight varieties of Nigerian maize and content of nitrogen, phosphorus and potassium in the leaf at flowering stage
Authors: Agboola Akinola A.
Published: March 2009

Studies of the relationship between yield and content of N, P and K in the ear leaf of eight varieties of Nigerian maize, tested for three growing seasons, indicated that the varieties have different critical nutrient levels, although the values obtained for individual varieties were not significantly different from the pooled average critical level for any of the nutrients. The critical levels ranged from 2·85 to 3·19% N, 0·20 to 0·27% P and 2·06 to 2·60% K, while their pooled averages were 3·10% N, 0·23% P and 2·44% K.

High ear leaf nutrient content was not a guarantee of high grain yield, and ear leaf nutrient values of low-yielding varieties were similar to those of the high-yielding varieties.
Effect of crude fibre upon feeding efficiency of cattle in ‘warm’ environments
Authors: Vohnout K. , Bateman J. V.
Published: March 2009

Results of this study show that daily intake of dry matter (DM) and digestible energy (DE) was lower for the ‘warm’ environment and ‘high’ fibre groups. Efficiency of DM utilization was also lower for these groups. However, efficiency of DE was essentially the same for both rations, being lower in the ‘warm’ group. The lower intake in the ‘warm’ environment was attributed mainly to the longer length of time that animals spent resting, which resulted also in lower growth rates. The data indicate that increasing the caloric density of feed, to compensate for reduced consumption, would make it possible to obtain proportional increases in energy intake. As interactions were negligible, this situation would apply to both environments studied.
A comparison between the effect of various photoperiods on the reproductive performance of Scottish Half-bred ewes
Authors: Newton J. E. , Betts J. E.
Published: March 2009

Four experiments are described in which attempts were made to increase the number of live lambs born per ewe per unit time. In the first experiment 22 Scottish Half-bred ewes were subjected to an artificial photoperiod. This resulted in 95 % of the ewes being mated 128 days after their previous lambing. It was estimated that artificial photoperiod brought the breeding season forward by about 5 weeks. The use of 1500 i.u. Pregnant Mare Serum had no significant effect on mean litter size. In the second experiment three artificial photoperiods were compared with natural daylength. In Group 2 photoperiod was decreased rapidly on 2 April from 18 to 10 h, in Group 3 photoperiod was decreased gradually on 2 April from 24 h and in Group 4 photoperiod was decreased rapidly on 28 May from 18 to 10 h. Group 5 was the control. Median intervals from parturition to next conception for Groups 2–5 were 70, 138, 68 and 131–5 days respectively; median intervals from onset of decreasing daylength to conception were 129, 200, 83 and 118–5 days respectively. Treatments 2 and 4 significantly reduced the interval from parturition to next conception but treatment 3 was unsuccessful. The interval from onset of decreasing daylength to conception was significantly shorter for treatment 4 than for treatment 2.

In Exp. 3 an unsuccessful attempt was made to extend the natural breeding season by preventing photoperiod from increasing for 3 months after 22 December.

In Exp. 4 a similar photoperiodic pattern was used for Groups 9 and 10 (16 h photoperiod decreasing rapidly to 8 h on 18 February). The contrast was that in Group 9 most of the ‘light’ was natural, in Group 10 all the ‘light’ was artificial. This pattern was compared with the natural daylength pattern (Group 8), an equinoctial treatment (Group 11) and a short-day treatment, 8h light, 16 h dark (Group 12). The median intervals from parturition to next conception for Groups 8–12 were 194, 102, 99, 156, 155 days, respectively. There was no significant difference in this interval between Groups 9 or 10. Type of ‘light’ therefore had no influence on the median interval from parturition to next conception; but photoperiodic pattern did. A rapid increase to 16 h light followed by a rapid decrease to 8 h (Groups 9, 10) was more effective than either the equinoctial treatment (Group 11) or the short-day treatment (Group 12). The treatments imposed on Groups 11 and 12 were more effective in shortening the median interval from parturition to next conception than the natural daylength pattern (Group 8). Time of year of mating had no effect on lambing percentage.

It was concluded that the sensitivity of sheep to photo-stimulation varied directly, with time from the onset of the next natural breeding season and with the speed of photoperiodic decrease.
The effect of supplementary winter feeding on the total yield and lactation curves of cows in a herd of British Friesian cattle
Authors: Wood P. D. P. , Newcomb R.
Published: March 2009

A tightly autumn-calving herd of British Friesian cattle, running throughout the year as a single group, received two different amounts of mineralized barley supplement per day during the winter of 1973/4. As they calved, alternate cows were allocated to one of two rates of supplementary feeding differing in the approximate ratio 2:3 which was applied according to the calendar and not specifically related to milk yield.

Average herd size for the year was 140 cows; average milk sales were 4680 kg/cow at a total supplementary concentrate use of 650 kg/cow. All cows had free access to selffeed silage reinforced with brewers' grains. Cows which received 50% more supplement from 8 September to 31 January (an extra 235 kg/cow) showed an improvement in total lactation milk yield of 248 kg/cow. Standard lactation curves were used to demonstrate a significant interaction between quantity of concentrates fed and season of production and showed that most of the improvement took place during the winter period.
ARC protein standards for growing pigs (including a comparison between field trial approach and replication at a single centre)
Authors: Braude R. , Hosking Zena D.
Published: March 2009

Results of a co-ordinated trial carried out at 20 centres indicated that increasing the dietary crude-protein percentage by 2·5 and the lysine by about 0·2 over the ARC recommended levels failed to improve performance or carcass quality, whereas decreasing these nutrients to a similar degree below the recommended levels adversely affected performance and carcass quality.

At four centres there were six to eight replicates. Substantial differences in estimates of both the level of response to a given treatment and the magnitude of treatment effects were observed between individual centres.

Factors affecting the size of these co-ordinated trials are discussed.
Nitrogen response and stocking rate of Pennisetum clandestinum pastures: I. Pasture nitrogen requirement and concentration, distribution of dry matter and botanical composition
Authors: Mears P. T. , Humphreys L. R.
Published: March 2009

Ammonium nitrate was applied to a kikuyu (Pennisetum clandestinum) dominant pasture at annual rates of 0, 134, 336 and 672 kg N/ha. Each nitrogen (N) rate treatment was continuously grazed at three stocking rates (SR) designed to apply similar grazing pressures at each N level and covering a range from 2·2 to 16·6 Angus weaner cattle/ha.

The N status of these pastures was periodically assessed 8–10 weeks after seasonal N applications by temporarily excluding stock and measuring D.M. and N response to additional ammonium nitrate application. Pasture growth response to additional N was constant and independent of SR and of annual N rate over the range 0 to 336 kg N/ha, despite wide variation in pasture availability. N concentration of plant shoots was increased by high SR and rate of N uptake was not significantly affected by SR. Pasture growth rate was positively related to annual N rate.

Herbage yield of kikuyu leaf, stem and litter on offer, was negatively related to SR but weight of underground organs was unaffected. Increasing SR increased the proportion of leaf and the rate of tillering. Pasture availability was positively and linearly related to N rate from 0 to 336 kg N/ha and maximal at 336 kg N/ha; the size of the litter fractions and underground organs was generally independent of N rate. N% in leaf and stem was reduced at low SR; N% of leaf, stem, litter, rhizome and root was positively related to N rate which was more influential than SR. The effect of SR on the size and relative distribution of the N in plant tops and litter fraction is discussed.

Kikuyu dominance was positively related to N rate and independent of SR. White clover invaded at No and N131 levels especially at a high SR.
Further studies on the utilization of nitrogen in silage based diets
Authors: Griffiths T. W. , Smith F. H.
Published: March 2009

Two digestibility and balance experiments were carried out using 12 growing heifers to compare first and second cut silages fed alone or with supplementary barley or barley and urea, and to measure the effects of the addition of urea to silage and barley diets at three levels of dietary energy.

Digestibility of gross energy (GE), N and modified acid detergent fibre (MADF) was higher in first cut than second cut silage diets, and although D.M. intake was slightly lower, metabolizable energy (ME) intake was significantly higher. Inclusion of urea increased the apparent digestibility of N but had no effect on the intake of D.M. or ME. Nitrogen retention was significantly higher on first cut than second cut silage diets and was significantly increased by the addition of urea when N intake was low. The relationship between daily N retention (DRN), ME intake (DME) and digestible N intake (DAN) was represented by an equation of the form:

DRN =C–2·164DME+0·447DAN–0·00512DAN2+0·0487DMExDAN,

but when apparent biological value (ABV) of dietary protein was high DRN was linearly related to DAN. These equations were used to estimate requirements for digestible N. The results of rumen fermentation studies suggested that the response in DRN to urea inclusion could be partially explained by the low rumen ammonia values on silage and barley diets.
Causes of inter-varietal differences in susceptibility to sodium toxicity injury in Phaseolus vulgaris
Authors: Ayoub Ali T.
Published: March 2009

Varieties of beans (Phaseolus vulgaris L.) were grown under both greenhouse and field conditions to determine the causes of inter-varietal differences in susceptibility to sodium toxicity injury. Varieties varied greatly in plant growth and survival on sodic soils under arid conditions. Environmental conditions were very important in determining differences in survival. Chemical analysis of plant parts indicated that varieties accumulated different amounts of sodium in the roots, stems and leaves. Sodium concentration in stems and leaves of sodium-tolerant varieties was controlled to a low level at lower degrees of injury.
The potential digestibility of leaf and stem fractions of grasses
Authors: Goto I. , Minson D. J.
Published: March 2009

The potential digestibility of leaf and stem fractions of Rhodes grass (Chloris gayana) and Pangola grass (Digitaria decumbens) were determined by incubating in vitro with rumen fluid for 4, 7, 11 and 14 days with reinoculation after 7 days. The mean drymatter solubility (DMS) of four leaf and four stem samples from the two species, increased from 53·6% after 4 days to 63·8% after 14 days with increases of 14·9 and 5·7% for leaf and stem respectively. Prolonged incubation of sheep faeces from these feeds gave similar patterns of DMS as those for the original feed.

To determine the cause of the observed rise in DMS, leaf and stem of Rhodes grass was incubated for 21 days with rumen fluid and Onozuka cellulase. When using cellulose, DMS increased by 7·7% compared with 14·6% when using rumen fluid. The higher DMS with rumen fluid was associated with an increase in the mean disappearance of lignin from 33·6% at 4 days to 52·6% after 21 days. After 14 days there was no further loss of lignin from most samples indicating the existence of a hard resistant lignin core.

It was concluded that when determining potential digestibility forages must be incubated with rumen inoculum for at least 21 days and that shorter incubation times may lead to biased conclusions.
Studies of some factors affecting the output of silk in Bombyx mori L
Authors: Gaaboub I. A. , Rawash I. A. , Mostafa S. M.
Published: March 2009

The results obtained showed that there was a clear relationship between the ability of larvae to assimilate mulberry leaves and the resulting cocoons. The mulberry varieties, Morus alba var. rosa, M. rubra and M. alba var. Ihu, had a conspicuous effect on weights of the resulting cocoons in the three races of silkworm (Novi, Belgharia 4 and S.A. 105) studied.

Results obtained also indicated that the length of the silk fibre and the weight of silk cocoons that yielded 1 kg of silk were largest when the larval diet was M. alba var. rosa or M. rubra, and were smallest when the larval diet was M. alba var. Ihu.

Results also showed that the protein content determined in the resulting silk was proportional to the protein percentage in the different mulberry leaves.

Feeding of larvae of the races Novi, Belgharia 4 and S.A. 105 on M. alba var. rosa and M. rubra leaves caused approximately one- to twofold increase in the fresh weights of larvae or pupae. Weights of fresh cocoons and cocoon cortex constructed by pupating larvae were largest when larval diet was M. alba var. rosa or M. rubra and were smallest when the larval diet was M. alba var. Ihu.
The influence of seed size on the performance of cereals in variety trials
Authors: Carver M. F. F.
Published: March 2009

The evaluation of the genetic potential of cereal varieties in variety trials will be accurate only if compensation can be made for all the variables known to influence the results, or if those variables are controlled. The influence of one such variable, seed size, on subsequent performance of crop plants, is well documented (wheat, Kittock & Law, 1968; beans, Ries, 1971; barley, McDaniel, 1969). McFadden (1963), working with barley, felt that seed size was such an important determinant of subsequent plant performance that he suggested that seed used in comparative testing systems should all be processed to the same seed range.