bluuebunny/crossref_metadata_2025 huggingface dataset:
Regrowth of perennial ryegrass as affected by simulated leaf sheaths
Authors: Davies Alison , Evans M. Eleanor , Exley Janet K.
Published: March 2009

Simulating the accumulation of dead leaf sheaths in perennial ryegrass by masking the tiller bases increased leaf and sheath length and tiller weight but decreased tiller production. Exposure of previously masked tiller bases or stripping back the subtending leaf and sheath to expose the tiller bud in its axil stimulated tiller production. A photomorphogenic effect is postulated which controls the partitioning of dry matter between the growth of new leaf and sheath tissue on existing tillers, and the development of new tillers from tiller buds.
Nutrition and growth of gnotobiotic lambs
Authors: Lysons R. J. , Alexander T. J. L. , Wellstead Patricia D.
Published: March 2009

Seventeen gnotobiotic lambs were reared up to 21 weeks of age on cows’ milk followed by sterile solid diets similar to diets fed to conventional lambs. Seven were given limited defined populations of rumen bacteria, seven were left uninoculated and three were dosed with rumen contents from conventional sheep (‘conventionalized’). The lambs were reared in four groups corresponding to four lambing seasons.

Gnotobiotic lambs fed cows’ milk ad libitumgrew at similar rates and converted feed into live-weight gain with similar efficiency to conventional lambs. The gnotobiotic lambs irrespective of inoculation and the two conventionalized lambs in the first three groups failed to maintain growth on solid diets when milk feeding had been stopped. However, three gnotobiotic lambs in the fourth group, two of which were inoculated, continued to grow satisfactorily for at least 6 weeks on a solid diet alone, and the inoculation of defined populations of bacteria appeared to confer an advantage. The conventionalized lamb in the fourth group suffered a severe temporary setback, following which it grew well.
The value of palm kernel meal in finishing diets for pigs: 1. The effect of varying the proportion of protein contribution from blood meal and palm kernel meal on the performance and carcass quality of finishing pigs
Authors: Fetuga B. L. , Babatunde G. M. , Oyenuga V. A.
Published: March 2009

Forty (20 barrows and 20 gilts) Large White and Landrace pigs allocated on the basis of litter origin, sex and initial weight to four treatment groups with mean initial weights of 50 kg were individually and semi-restrictedly fed to about 93 kg one of four diets containing 18·8, 28·5, 38·2 and 46·5% palm kernel meal (PKM) and 11·3, 8·4, 5·5 and 4·6% blood meal respectively such that the ratio of protein contribution to the diet from blood and palm kernel meals were 2·7:1, 1: 1·3, 1: 1·6 and 1: 2·30 for diets 1, 2, 3 and 4 respectively. Growth performance was measured over the liveweight range of 50·93 kg at which latter weight the pigs were slaughtered for carcass evaluation. Live-weight gain and feed efficiency were highly significantly influenced by varying the levels of palm kernel meal and blood meal, the lowest level of palm kernel giving significantly the best rate and efficiency of gain. There was a tendency for carcass leanness to improve as the proportion of dietary protein supplied by palm kernel meal was increased, only the differences for lean meat percentage were however significant. Carcass cuts as percentage of total carcass did not appear to be influenced by the level of palm kernel meal in diets except for percentage fat cuts which decreased significantly (P < 0·05) as the dietary levels of palm kernel meal were increased.
Physiological studies on the leaf blades of wheat (Triticum aestivum L.) in relation to nitrate assimilation and grain protein accumulation
Authors: Nair T. V. R. , Abrol Y. P.
Published: March 2009

Two wheat (Triticum aestivum L.) cultivars, Shera and Kalyansona, which differ in grain protein percentage and in its enhancement by fertilizer application were selected for the present study. The analysis was confined to the leaf blades of the main shoot of plants grown at three rates of application of urea giving 0 (N0), 90 (N90) and 180 (N180) kgN/ha. Cv. Shera produced ten leaf blades on its main shoot while cv. Kalyansona had 11. The total dry weight duration of the leaf blades of cv. Kalyansona was higher than that of cv. Shera, particularly at N90 and N180. This was due to a great increase in dry weight of the leaf blades in response to fertilizer nitrogen and to an additional leaf blade. In both the cultivars the in vivo nitrate reductase (NR) activity was highest in the first formed leaf blades and showed a gradual decline in the successively formed ones, at all three nitrogen levels. Cv. Shera showed higher NR activity than cv. Kalyansona in most of the weekly samplings (weighted mean values) through the season. Seasonal mean NR activity was higher in cv. Shera at all three rates of nitrogen application. The difference was, however, significant only at N90. The total amount of NO3- reduced by the leaf blades, which is a function of their NR activity and dry weight duration, was higher in cv. Shera than in cv. Kalyansona at N0. However, at N90 and N180 the differences decreased because of the higher dry weight duration of the leaf blades of cv. Kalyansona.

The estimated amount of NO3- assimilated was less than the actual reduced N at harvest at N0 but at N90 and N180 there was an overestimation. The grains of cv. Kalyansona showed significantly lower protein percentage than cv. Shera at all three nitrogen levels. While low nitrogen per spike was the main cause of lower protein percentage in cv. Kalyansona at N0 as compared with cv. Shera, distribution of almost the same amount of nitrogen to a larger quantity of grains was largely responsible for the lower protein percentage in this cultivar at N90 and N180. The results are discussed in relation to selection criteria used in breeding programmes for the improvement of grain protein content of wheat cultivars
The incidence of swarming among colonies of honey-bees in England
Authors: Simpson J.
Published: March 2009

Some published figures relating to the incidence of swarming have been examined, and records obtained in the routine examinations of colonies in honeyproducing apiaries have been analysed. It is concluded that in these apiaries between 10 and 40% of colonies would swarm in an average year, if they were given excess hive space and otherwise left alone. The proportion of colonies which produced queen cells varied from year to year and from one apiary site to another. This variation was presumably due to environmental factors, but it was substantially independent of those factors which determined honey yield. There was no evidence that it was due to the effects of conditions in the years when the queens were reared. After the end of June, at least, the tendency for colonies to produce queen cells was markedly less with queens of the current year than with queens of the previous year, and was probably also less with queens of the previous year than with still older queens. Queen cells were most frequently observed in colonies in the latter half of May and in June and July. The mean time of queen-cell production varied from year to year. Many colonies which began to rear queens eventually ceased to do so with no other treatment than removal of queen cells. Queen rearing did not begin and end in all colonies at the same time; many colonies began rearing queens after others had stopped.
Studies of the cattle of Northern Rhodesia: I. The growth of steers under normal veld grazing, and supplemented with salt and protein
Authors: Walker C. A.
Published: March 2009

1. With steers of indigenous cattle, the supplementation of veld grazing with two levels of salt with and without protein in the dry season has been investigated.

2. The feeding of 1 oz. of salt speeded up growth to a strongly significant degree, but under the experimental conditions no benefit was obtained during the dry season from adding a protein supplement to the salt. Protein supplementation without salt produced no significant effects upon growth.

3. The addition of 2 oz. of supplementary salt was found to give some increase in growth when compared with the control, but appeared to exert an inhibitory action as compared with the lower salt level, and again there was no benefit gained from the addition of a protein supplement in the dry season. No reason can yet be given for this.

4. Additional evidence has been given to support the suggestion that the tropical indigenous animal possesses the capacity to stop growing during adverse nutritional conditions.
Seasonal variation in the egg production of fowls: effect of temperature and change of day length
Authors: Hutchinson J. C. D. , Taylor W. W.
Published: March 2009

1. Two groups of pullets were reared on a 12 and a 23½ hr. day length respectively and at an environmental temperature of 64–65° F. Two months after the first bird came into lay, the day length of the second group was reduced to 12 hr. over a period of about 8 weeks (phase I).

2. Both groups came into production at the same time, but the group reared on a 23½ hr. day grew more rapidly.

3. The reduction in day length caused moulting and low production for several months, whereas the group which had been reared in a 12 hr. day continued to lay steadily.

4. Soon after the reduction of day length half of each group (subgroups B and D) was exposed to an artificial thermal autumn and winter, which had no detectable effect on production (phase II). After this the temperature was allowed to rise to 64–65° F.

5. When the day length of the remaining birds (subgroups A and C), still kept at 64–65° F., was increased to 23½ hr., there was no significant increase in production (phase III).

6. When their day length was then reduced to 12 hr., they moulted heavily and went out of production (phase IV).

7. Simultaneously the day length of subgroups B and D was increased to 16J hr. (phase IV). This had no significant effect on production.

8. The yield of the birds which had their day length reduced at the beginning of the experiment was twenty-three ovulations less than that of the others at the end of the artificial winter, and nineteen less at the end of the laying year. The laying year was concluded before phase IV. There was no difference in yield between the birds which had an artificial autumn and winter and those which lived in a warm environment.

9. Data are given on the frequency distribution of the yield after a reduction in day length, over the remainder of the year, and also on the correlation between the yields in these two periods.

10. The eggs of the group reared in a 23½ hr. day length tended to be larger than those of the other group in conformity with their larger body weight. Apart from this the various treatments had no effect on egg weight.

11. There was no relation between the egg yields and the variations in absolute and relative humidity.

12. In a subsidiary experiment it was found that, if the reduction in day length was completed a month before the birds began to lay, there was no significant effect on subsequent production.

13. In the light of these experiments it seems that the essential cause of winter pause and the annual rest, in birds given supplementary lighting, is the decline in day length in late summer and autumn.
The prediction of the voluntary feed intake of dairy cows
Authors: Vadiveloo J. , Holmes W.
Published: March 2009

Information on the total dry-matter intake (TDMI), concentrates supplied (C), live weight (LW), week of lactation (WL), milk yield (MY) and composition, quality of forage fed to, and parities of, 385 cows from five different sources were assembled to develop appetite prediction equations. The equations were based on multiple regression and least squares constants and were calculated using the data from each source and the data pooled from all sources. The major factors affecting total dry-matter intake (TDMI) were C, LW, WL and MY and for the pooled data these factors explained 73–76% (R2) of the total variation in TDMI. The predictive values of some of the equations were tested against independent sets of data and for groups of cows and individual cows, the equations predicted TDMI within ±1·1 and 1·6 kg, respectively. The application of the equations in the field is discussed and some suggestions made for increasing the R2 of future appetite equations.
Factors affecting the performance of ewes fed ad libitum until weaning and the performance of their lambs
Authors: Economides S.
Published: March 2009

Nutritional and other physiological factors are causes of variation in milk yield. In particular, the energy intake and the suckling stimulus of lambs greatly affect the milk yield of ewes in early lactation (Treacher, 1978; Hadjipanayiotou & Louca, 1976; Peart, Doney & MacDonald, 1975).

In most eastern Mediterranean countries ewes are milked after weaning and the weaning age and the suckling regime determine both the amount of saleable milk and the rate of growth of lambs. The aim of the present work was to study factors affecting the milk yield of Chios ewes fed ad libitum and the growth of their lambs.
The intensive production of herbage for crop-drying Part VI. A study of the effect of intensive nitrogen fertilizer treatment on species and strains of grass, grown alone and with white clover
Authors: Holmes W. , MacLusky D. S.
Published: March 2009

1. An experiment is described which lasted for 5 years and in which a comparison was made of twelve grasses or grass mixtures under different fertilizer nitrogen treatments and also when grown with clover. The herbage was cut 4–6 times in each season. Adequate amounts of mineral fertilizers (280–340 lb. K2O and about 100 lb. P2O5 per acre per annum), and the following nitrogen treatments were applied: (1) no nitrogen, no clover, (2) grass sown with clover, (3) 140–208 lb. nitrogen per acre per annum in four to six equal dressings, (4) 350–416 lb. nitrogen per acre per annum in five and six equal dressings.

In 1951, 1952 and 1953 the clover dominant swards (treatment 2) were split between the following treatments; (X) as (3) above, (Y) 35 lb. nitrogen per acre in spring and again in late summer, (Z) no nitrogen as (2) above.

2. The average yields for the 4 years were 2180, 5940 and 8300 lb. dry matter per acre, and 290, 850 and 1460 lb. crude protein per acre for treatments 1, 3 and 4. With treatment 2 the average yields were 2830 lb. dry matter and 400 lb. crude protein in 1949 and 4270 lb. dry matter and 820 lb. crude protein in 1950. An approximate average yield for the 4 years from treatment 2 was 4630 lb. dry matter and 860 lb. crude protein. In 1951–3 average yields for treatments 2X, 2Y and 2Z were, 7240, 6340 and 5750 lb. dry matter and 1240, 1180 and 1100 lb. crude protein per acre.

3. There were considerable differences between grasses in nitrogen response and compatibility with clover. The highest yields with fertilizer nitrogen were given by cocksfoot strains, but, in the presence of clover, ryegrass and timothy strains gave the highest yields. There were also differences between strains within each species.

4. Mean crude protein contents were, for treatments 1, 3 and 4, 13·3, 14·3 and 17·6%, and for treatments 2X, 2Y and 2Z in 1951–3, 17·2, 18·6 and 19·1%. Differences between species were significant in only a few instances.

5. The distribution of yield over the season was most regular with treatment 4. Cocksfoot species gave the least variable yields from cut to cut, while those from timothy and ryegrass swards were the most variable.

6. Treatments 3 and 4 maintained a high proportion of sown grasses in the swards. In treatment 2 the clover percentage rose to a high level by 1950. A high percentage was maintained under treatment 2Z in 1951–3. Treatment 2Y depressed the clover content in some grasses, and treatment 2X further depressed it in those grasses. A fairly high clover content was maintained, however, even with treatment 2X with some timothy strains and meadow fescue.

7. The mineral fertilizers applied maintained the soil analysis at a satisfactory level.

8. The results are discussed with special reference to the relative merits of fertilizer nitrogen and clover nitrogen and to the differences between species and strains.
Heat-tolerance studies of fat-tailed sheep in the subtropics
Authors: Hafez E. S. E. , Badreldin A. L. , Sharafeldin M. A.
Published: March 2009

Forty adult (15 months old) fat-tailed Egyptian rams and ewes of the Rahmani and Ossimi breeds were available at the Animal Breeding Research Farm, Giza, Egypt (30° N.). Body temperature and respiration rates were measured twice weekly throughout the year 1953–4. On days of observations, four readings were taken at 10 a.m., 12 noon, 2 p.m. and 4 p.m. Skin temperature was measured once weekly at noon for nine body regions, using a precision bridge thermometer. The effects of docking and pregnancy were also studied.

1. There were seasonal variations in body temperature and respiration rate. The maximum values were during summer and the minimum during winter. The seasonal rate of change was greater in respiration rate than in body temperature.

2. Body temperature was 39·1 and 39·0° C. for the Ossimi rams and ewes respectively, while it was 38·9° C. for both Rahmani sexes. Respiration rate per minute was 42·0, 39·3, for Ossimi rams and ewes and 38·2 and 35·9 for Rahmani rams and ewes respectively. Body temperature and respiration rate were higher in the Ossimi than in the Rahmani breed, and in the males than in the females. Breed differences may be related to anatomical differences such as body conformation, size of skull and tail, thickness of skin and subcutaneous fat and differences in coat characteristics. Sex differences may be associated with the live weight of the animals as well as differences in the hormonal system.

3. Pregnancy had no effect on body temperature and respiration rate in either breed.

4. Different experimental groups reacted similarly with respect to diurnal variations in body temperature and respiration rate; the lowest values being at 10 a.m. and the highest at 4 p.m. Maximum body temperature and respiration rate preceded maximum environmental temperature by 2–4 hr. The diurnal rate of change in respiration rate was higher than that in body temperature. The diurnal changes in body temperature and respiration rate of animals were mainly due to the changes in the environmental temperature throughout the day.

5. (a) Skin temperature varied from 33·7 to 39·7° C., according to season and body region. Seasonal variations in skin temperature of different body regions showed the same trend.

(b) Highest skin temperatures were recorded for middle and upper fat tail, back thoracic and middle scrotum regions, while the lowest were recorded in lower and upper scrotum, lower tail and neck ventral regions. The breast region had an intermediate skin temperature. The different skin temperatures were due to anatomical differences such as the thickness of subcutaneous fat, density of covering wool or to differences in the amount of blood supply.

6. Docked rams had a lower skin temperature and respiration rate than controls, denoting better heat regulation. This may be due to metabolic differences or anatomical changes in the body such as the thickness of subcutaneous fat.
Variety × environment interactions in sugar beet variety trials
Authors: Beckett J. L.
Published: March 2009

The effects of a range of environmental factors on the performance of six varieties of sugar beet at 62 trial sites are considered with special reference to the identification of those environmental factors important in explaining observed variety × environment interactions.
Screening technique for frost resistance in Brassica Oil seeds
Authors: Dhillon S. S. , Larsson S.
Published: March 2009

Brassica oil seeds grown in India are occasionally damaged by frost, causing severe losses. A technique was developed to screen germplasm at the seedling stage. Twentyfour lines of B. campestris, B. juncea and B. napus were grown in plastic boxes in a glasshouse in a mixture of peat and sand. The seedlings were frozen after hardening for 2 days at 1 °C. Observations were recorded after 4 days, using a five-point scale. Frost tolerance index (FI) is calculated as the average value for injured plants for each line. Eight lines for each of the three species were tested. B. campestrisas a group showed better frost tolerance. Some lines of Indian mustard also showed good tolerance of low temperature (– 5·5 °C). These findings show good agreement with observations recorded in the literature. The method is detailed and discussed. Suggestions for future programmes are made.
Further studies on the fattening value of grass silage and on the effect of the dry-matter percentage of the diet on dry-matter intake in ruminants
Authors: Dodsworth T. L.
Published: March 2009

1. A feeding trial is described including four groups of cattle fed on silage only, two mixtures of silage and roots, and roots, straw, hay and oats.

2. The live-weight gains made are recorded together with the rate of dry-matter intake.

3. The efficiency of the dry matter of the diets was calculated.

4. Silage fed alone produced a significantly greater rate of fattening than the other three diets.

5. Cattle receiving roots in the morning and silage at night consumed 10·78% more dry matter and made greater live-weight gains than cattle fed on silage in the morning and roots at night.

6. Calculation of the starch values of the roots and silage showed that these are higher when fed together than when silage is fed alone or when roots are fed with straw, hay and oats.

7. An experiment is described designed to determine the effect of the dry-matter percentage of the diet on dry-matter intake in ruminants and of sudden changes in dry-matter content on digestibility.

8. Sheep receiving 19·46% dry-matter silage consumed 16·7% more dry matter and 19·8% more starch equivalent than sheep eating 15·85% dry-matter silage.

9. When the dry-matter percentage of the silage fell from 19·46 to 15·77 the digestibility of the dry matter fell by over 10%.

10. The starch equivalent of the silage when fed alone was determined from the results of a digestibility trial and according to the performance of the cattle in the feeding trial. The values found were 65·88 and 66·15% respectively.

11. The losses suffered in silage-making in twentyfive silos are recorded and discussed. The loss of dry matter and crude protein both average approximately 40% of that ensiled. The need for finding methods of reducing these losses is again stressed.
Nutrition of the bacon pig XVII. The nutritive value of condensed fish solubles
Authors: Evans R. E.
Published: March 2009

Investigations have been carried out in this department in recent years with the object of establishing the minimum protein requirements of the bacon pig. The results were recently summarized in thisJournal(Woodman & Evans, 1948). The minimum protein standards recorded in that communication are consistent with the attainment of the maximum rate of growth compatible with the net energy content of the diet. The basal foods employed consisted throughout of 2 parts of barley meal and 1 part of middlings (fine bran), together with a little lucerne meal and minerals. Briefly, it was found that such a diet, when supplemented with 7% of white-fish meal, supplied the minimum amount of digestible protein required for the quickest possible rate of growth between weaning and 90 lb. live weight, when the level of feeding was such as is shown in the feeding chart (see Table 7). It was also found unnecessary to include any protein concentrate in the diet beyond 90 lb. live weight to ensure the maximum rate of growth over this later period. The requirements were based on the results of statistically designed growth trials, and were confirmed by nitrogen-balance determinations carried out in metabolism crates. It was found that nitrogen retention was just as favourable on the basal diet supplemented with 7% of white-fish meal as when the protein level was increased by feeding higher amounts offish meal.
Studies on the storage of potatoes II. The temperature conditions inside potato clamps
Authors: Crook E. M. , Watson D. J.
Published: March 2009

Continuous records of the temperature of potatoes stored in clamps were made in 1942–3 (one clamp) and in 1943–4 (three clamps). In the first year, the temperatures at various positions in the clamp coverings were also recorded.

The temperature at the middle of the potato heap showed a drift with time similar to that of mean air temperature. Deviations of mean air temperature from smooth trend, lasting for about a week, had no effect on the temperature of the potatoes; longerperiod deviations were reflected in the temperature of the potatoes after a lag of about a week. The difference in weekly mean temperature between potatoes and external air averaged about 1–5° C. in 1943–4. In 1942–3 it was greater, increasing to over 20° C. in April, because bacterial rotting of the potatoes following blight infection increased the rate of heat production and caused the clamp to collapse at the end of April.
An analysis of carcass measurements of post-war British bacon pigs
Authors: Harrington G. , Pomeroy R. W.
Published: March 2009

(a) Measurements made on sides of bacon exhibited since the war at the National Pig Breeders' Association carcass shows at Stirling and Peterborough and on various commercial sides have been analysed to investigate differences between the shows, the years and the sexes.

(b) In the Large White exhibits the sides from gilts were on average longer, thicker in the belly, thinner in back fat and with better developed eye muscles than the sides from hogs.

(c) The area of the eye muscle of the carcasses entered in these shows between 1948 and 1952 shows an unexplained decrease over this period. The width of the eye muscle is the only character showing a definite show difference, being larger at Stirling than at Peterborough.
The influence of the environment upon the estimated dressed carcass weight of fat sheep in West Wales (1943–6)
Authors: Phillips R. , Brown E. H.
Published: March 2009

1. The changes in the sheep population and in the sales of fat sheep have been examined for the West Wales region for the period 1940–8. These changes consist of a gradual annual decline in sales, whilst the severity of the 1947 winter conditions brought about a rapid drop in both sales and population by nearly 33% from 1946 to 1947.

2. Analyses of sales of the four categories of fat sheep—rams, ewes, sheep and lambs—throughout the twenty-five collecting centres have been completed for the 4 years, 1943–6. These showed that lambs accounted for 85% of the fat sheep sales in this region.

3. It was found that the average estimated dressed carcass weight (e.d.w.) of the four categories of sheep (rams, ewes, sheep and lambs) declined gradually from the collecting centres of west Pembrokeshire to the inland centres on the eastern boundaries of the region. This cline is also found in the case of the summer suckling lamb, the autumn wether lamb and the winter-fed fat lamb.
The analysis of change-over trials
Authors: Patterson H. D.
Published: March 2009

The analysis of simple change-over trials based on Latin squares is considered. It is shown that several difficulties are encountered when estimates of residual effects are required. In particular, there may be biased error variances.

In certain circumstances the amount of bias in the error variance can be estimated in a proportion of the experiments based on a given design. If this bias is sufficiently large to be of importance an average correction can be calculated for use with further experiments of the same type.
The seasonal output of pastures sown with ultra-simple seeds mixtures
Authors: Hughes G. Pearson
Published: March 2009

An attempt has been made to evaluate the role of seven ‘ultra-simple’ seeds mixtures in the production of pasture during the grazing season. The individual value of each mixture is assessed and its period of production described.

Pasture output was measured in dry matter and protein yields along with live-weight gains obtained with fattening cattle.
Evaluation of the ability of two carcass conformation systems to predict carcass composition of sheep
Authors: Bass J. J. , Carter W. D. , Woods E. G. , Moore R. W.
Published: March 2009

Conformation of carcasses from 107 Romney ewe lambs was determined using two visual scoring systems and the scores related to chemical and dissected carcass composition. The conformation system which evaluated the lateral profile of the hind leg failed to improve the prediction of carcass composition. The Meat and Livestock Commission system used in Great Britain separated carcasses on weight and fatness, the higher classes having the heaviest and fattest carcasses. After adjustment for carcass weight and fatness the higher conformation classes had the lightest bones and the heaviest weight of muscle, and some of the muscles weighed were shorter and deeper than those of the lower conformation classes.
Studies on carotene in relation to animal nutrition: Part II. The development and distribution of carotene in the plant and the carotene content of some common feeding stuffs
Authors: Seshan P. A. , Sen K. C.
Published: March 2009

1. Under artificial conditions of plant growth, the relative development of carotene is very poor. The absence of sunlight appears to be the main cause.

2. Under field conditions, the maturity of a plant plays an active part in determining the carotene content, which gradually decreases with age. This phenomenon is less discernible among the legumes. The nitrogen content generally runs parallel to the carotene.

3. The species of the plant seems to be a determining factor in the capacity of the plant for carotene formation.

4. A study of the distribution of the carotene in different parts of the same plant shows that the leaves of grasses contain 3·1–11·0 times more carotene than the stems. The earheads and stems have almost equal amounts. With the growth of berseem and lucerne, the ratio of carotene in leaf to carotene in stem shows a tendency to increase, suggesting that the deterioration in the stem is comparatively more rapid than in the leaves when the plant becomes older.
The estimation of the yields of cereal experiments by sampling for the ratio of grain to total produce
Authors: Cochran W. G.
Published: March 2009

In a number of cereal experiments, three on wheat, three on barley and one on oats, the yields of grain and straw per plot were estimated by weighing the total produce on each plot and taking samples, usually from the sheaves, to estimate the ratio of grain to total produce. This paper discusses the sampling errors of this method. The method proved considerably less accurate than was anticipated from previous calculations made by Yates & Zacopanay. Amongst the reasons which are suggested to account for this are the larger sizes of plot and sampling unit used in these experiments and the additional variability introduced by the presence of weeds, undergrowth and moisture.

Nevertheless, the method appears to be substantially superior to the older method of cutting small areas from the standing crop, without weighing total produce, only about one-quarter of the number of samples being required to obtain results of equal precision.

The samples were taken both by an approximately random process and by grabbing a few shoots haphazardly from each of several sheaves. The grab samples gave on the whole a slightly higher yield of grain, the greatest positive bias being 6%, but were otherwise just as accurate as the random samples. Since the grab samples can be selected and bagged in about one-third of the time required for random samples, their use is recommended for the majority of the samples required in any experiment.

The validity of an approximate formula for calculating the variance of a ratio (in the present instance the ratio of grain to total produce) is discussed briefly in an appendix.
Studies on Carotene in relation to animal nutrition: Part III. Stability of carotene in plant material with special reference to hay making and storage
Authors: Seshan P. A. , Sen K. C.
Published: March 2009

1. An experimental study has been made of the effects of heat, light, air, enzymes and bacteria on carotene destruction, when green fodder is dried and stored as hay.

2. Carotene in green fodders can be destroyed by autoclaving or other forms of heating in the presence of air. The extent of destruction depends upon the period of heating.

3. Carotene is not destroyed if green plants are dried in a vacuum.

4. Atmospheric oxygen plays the predominant part in the destruction of carotene; and heat, light and moisture are merely accelerating agents. The destruction of carotene during storage is due mainly to a slow spontaneous oxidation of the pigment in plant material.

5. The utility in India of grass drying or hay making with the specific object of providing vitamin A supplements is questionable, because of the carotene destruction during storage under prevailing temperature and climatic conditions.
The minerals in the clay fractions of a black cotton soil and a red earth from Hyderabad, Deccan State, India
Authors: Nagelschmidt G. , Desai A. D. , Muir Alex.
Published: March 2009

The mineral compositions of the clays from a red earth and a black cotton soil from Hyderabad, Deccan State, India, occurring in close proximity in the field are determined. Both soils are derived from the same or from very similar parent rocks, a coarsely crystalline granite or gneiss.

For both soils there is practically no variation in the mineralogical composition of the clay throughout the profile, but for any given clay there is some variation with grain size. The main contrast between the two is that the red clay contains predominantly kaolinite or halloysite, whereas the black clay contains mainly beidellite, a member of the montmorillonite group. The topography appears to be the principal factor associated with this difference in minerals, and the processes of weathering believed to have produced the contrasted clays are discussed with reference to experiments on the leaching of felspar in the laboratory and on hydrothermal synthesis.
Further investigations of the feeding value of artificially dried potatoes: the composition and nutritive value of potato cossettes, potato meal, potato flakes, potato slices and potato dust
Authors: Woodman H. E. , Evans R. E.
Published: March 2009

The present account is a sequel to an earlier publication on the composition and feeding value of potato cossettes and meal. It deals with the composition, digestibility and nutritive value for pigs and ruminants of potato flakes and slices, theresults of a large-scale pig-feeding trial with potato slices and the composition and value for pigs of potato dust, a by-product of the manufacture of potato slices. Details of the processes of production of these various dried potato products are included in the text.
Seed disinfection: V. The stripe diseases of barley and oat
Authors: Dillon Weston W. A. R. , Eric Taylor R.
Published: March 2009

In the past twenty years there has been no noticeable decrease in the number of Helminthosporium infected oat and barley seed samples examined at the Official Seed Testing Station, Cambridge, and in the course of advisory practice. No reduction in the intensity of the seedling diseases caused by Helminthosporium has been noted during the first ten years under review. Formalin and copper carbonate were ineffective as seed disinfectants in reducing seedling mortality, and copper sulphate, although partially effective, had serious phytocidal effects and consequently cannot be recommended. Since the advent of the organo-mercury seed disinfectants a steady improvement in the control of these diseases has been noted, and field tests of such dressings have shown them to be eminently satisfactory. Barley straw infected with H. gramineum has been shown to be a source of secondary infection of barley seedlings.
Observations on the mineral metabolism of pullets. V: Acid-base equilibrium and reproductive activity
Authors: Common R. H.
Published: March 2009

1. Calcium and phosphorus balance experiments with pullets during which the plasma alkali reserve of the birds was followed are described. Evidence is produced in support of the view that the onset of reproductive activity in the pullet is accompanied by an increase in plasma alkali reserve, as well as of calcium retention, provided the ration contains adequate calcium carbonate.

2. These high levels of plasma alkali reserve tend to decrease with the beginning of laying, but apparently the plasma alkali reserve of laying birds tends in general to remain higher than that of the non-laying bird or of cocks.

3. The possible bearing of these observations on bone mineral composition and Ca/P retention ratios is discussed.

4. It is shown that on a cereal ration moderately low in calcium, where the apparent digestibility, of phytic acid phosphorus is of the order of 40–70%, it was not possible to correlate apparent digestibility with the calcium metabolism of shell formation. When the same ration was supplemented with 5% calcium carbonate, so that the apparent digestibility was of the order of 9–25%, then it was possible under circumstances of intense laying to detect a slight increase of apparent digestibility in association with laying.
Further investigations on artificial insemination of sheep
Authors: Anderson J.
Published: March 2009

The results obtained from artificial insemination of high grade Merino sheep in Kenya are given and discussed in relation to the season of the year, time of insemination during oestrus, the number of inseminations in each oestrous period and the degree of dilution of sperm.
The composition and digestibility of Northern Irish ryegrass seed and ryegrass seed cleanings: II. Data for ‘flatweed’, ‘hairgrass‘, and commercial Yorkshire fog seed, with a note on inorganic constituents
Authors: Rutledge W. A. , Common R. H.
Published: March 2009

1. Data for the composition and digestibility of certain by-products of the ryegrass seed cleaning industry are presented in amplification of data already published.

2. It is shown that the ‘hairgrass’ fraction of ryegrass seed cleanings has a starch equivalent somewhat superior to that of pure ryegrass seed or oats, and that this may be ascribed in all probability to its content of ratstail fescue seed.

3. It is shown that the ‘flatweed’ fraction, consisting chiefly of buttercup seed, has a starch equivalent, on a dry-matter basis, about three-quarters that of oats or pure ryegrass seed, and that it is, in spite of a relatively high content of digestible oil, among the least valuable constituents of the cleanings, apart from dust, straw and other worthless material.

4. Commercial Yorkshire fog seed is shown to have a feeding value comparable to that of pure perennial ryegrass seed.

5. Some data are presented regarding the inorganic constituents of ryegrass seed and ryegrass seed by-products.
Economies in the use of animal by-products in poultry rations I. Vitamin and amino-acid provision for starting and growing chicks
Authors: Carpenter K. J. , Duckworth J.
Published: March 2009

1. Chicks from commercial sources were housed intensively and fed on a series of rations containing decorticated extracted groundnut meal as the main supplementary source of protein, with and without additions of animal by-products and aureomycin. Parallel groups received rations conforming to Government regulations in their content of sources of animal protein.

2. Growth and feed efficiency up to point of lay were as good in groups fed on all-vegetable rations, containing 18% of crude protein in the starting ration and 16% in the growing ration, as in groups fed on regulation rations of the same protein content.

3. Performance on the all-vegetable ration up to 6 weeks of age was not as good as on the regulation ration. This inferiority could be largely or wholly corrected by adding extra groundnut meal and condensed fish solubles to the ration. Growth and feed efficiency over the whole rearing period were not improved by the addition of these supplements.

4. Addition of aureomycin stimulated growth over the whole rearing period but failed to improve feed efficiency.

5. Protein levels in the ration, the provision of animal protein factor(s) and aureomycin were without effect on the age at which laying began.

6. Current estimates of the chick's requirement for certain amino-acids appeared to be too high when this type of ration was used.

7. The addition of riboflavin to these starting rations was essential. When this was done mortality was low, leg weakness absent and feathering rate normal.
The laboratory determination of the protein digestibility of silage
Authors: Barnett A. John G. , Miller T. B.
Published: March 2009

1. The relation between the soluble-nitrogen content of grass silage and the pepsin digestibility has been investigated, and formulae have been derived for calculating the protein digestibility in the silage dry matter from the determined solublenitrogen content.

2. Comparisons have been made between the calculated results for protein digestibility, the results using the formulae of Watson and Dijkstra and the digestibility as determined on sheep.

3. The peculiarities of molassed silage in the above connexion have been noted.
Plant breeding studies in leguminous forage crops I. Natural cross-breeding in winter beans
Authors: Fyfe James L. , Bailey Norman T. J.
Published: March 2009

1. If a crop varies in respect to a character which shows simple Mendelian inheritance then it is possible to estimate the proportion of cross-fertilization within the crop from the data obtained by (i) drawing plants from the crop and scoring them in respect of the character, then (ii) growing their separate progenies and scoring them.

2. Maximum likelihood expressions are given for the estimation of p and f { = (1 — α)/(l + α)} from the genotypic classification of the parents and from the phenotypic classification of the progenies; where p is the gametic frequency of the dominant allel and α is the proportion of fertilizations in which the pollen is equally likely to come from any plant in the population.

3. When the above expressions are applied to a case in winter beans, in which the parent plants were selected for high yield it is found that the different estimates of p agree, but those of f do not.
Observations on the mineral metabolism of pullets: VI. The mobilization of body calcium for shell formation
Authors: Common R. H. , Hale R. W.
Published: March 2009

1. Some recent developments of mineral balance studies on laying fowl are discussed and applied to the interpretation of the average results of twenty-six balance experiments with pullets.

2. Several of the experiments are re-examined in detail from the same standpoint.

3. A tentative hypothesis covering the relations between the calcium metabolism of shell formation and the calcium-phosphorus metabolism of bone is put forward on the basis of this reconsideration of available data. It is suggested that some degree of mobilization of skeletal calcium is a normal feature of shell formation in the fowl, the fraction of bone mineral material mobilized always having a higher Ca: P ratio than the skeleton as a whole, although the actual ratio may vary with the calcium in the diet and with the form in which the calcium is provided.
Laboratory experiments on evaporation from fallow soil
Authors: Penman H. L.
Published: March 2009

Experiments on evaporation from freely drained soils are described. Under isothermal conditions characteristic winter field behaviour is obtained, even when the air drying power is greater than its normal English midsummer value. Characteristic summer field behaviour is obtained when the rapid drying of a thin surface layer is achieved, either by using an extremely high air temperature under ‘isothermal’ conditions, or by raising the surface temperature by means of radiation—the normal method in nature. The effect of a high salt concentration in the soil water is shown to lead to greater evaporation losses and to a tendency for the salt to concentrate in the more salty patches.

It is suggested that mulching will only be beneficial during the isothermal part of the year, i.e. when soil surface and air temperature are approximately equal, and that it will have little effect on water conservation where the soil will be self mulched by the action of summer sunshine. The cause of this self-mulching action is briefly considered in the light of our limited knowledge of soil water dynamics; it appears to depend on the existence of a dual mechanism of water movement in soils—as liquid and as vapour—the rates of movement being very different functions of moisture content and moisture gradient.
Compressibility curves as a quantitative measure of soil tilth
Authors: Blair G. W. Scott
Published: March 2009

1. A preliminary account is given of experiments on the compressibility of soils in field condition, and two methods for obtaining compressibility curves, one for the field and one for the laboratory are described. The laboratory apparatus automatically draws a curve relating deformation to the square root of the load built up.

2. The theoretical relationship between load and deformation is discussed, the conclusions reached being at this stage semi-quantitative.

3. Laboratory compression curves are shown to indicate the characteristics of soils in various states of tilth, and the effects of drainage condition, frost action, etc. are discussed.

4. Such factors as size of soil crumb, depth of layer tested, and moisture content of soil samples for laboratory studies are considered.

5. Preliminary field experiments are described in which the effect of simple cultivation processes on soil compressibility were measured.

6. Tentative conclusions about the significance of the differences in the shape of the laboratory curves are given, though these may need to be modified, and will certainly be extended following further experimentation.
Digestibility trials with poultry: VII. The digestibility of wheat offals, with a note on the apparent discrepancy between the digestibility coefficients and nutritive values of these products
Authors: Halnan E. T.
Published: March 2009

1. Digestibility determinations of broad bran, straight-run middlings and fine middlings are here reported.

2. On the basis of these determinations bran would appear to be a relatively dear feeding stuff for use with poultry, as compared with the finer grades of milling offals.

3. In the case of chick feeding mixtures, the finer milling offals suffer from the disadvantage of causing pasting in the mouth, this disadvantage militating against their too extensive inclusion in chick feeding mixtures. From the evidence obtained in these experiments it would appear that this disadvantage would come into play when more than 40 per cent of the total mixture consists of the finer offals.

4. From the point of view of economy and efficiency of utilization, a mixture of bran and middlings would appear to be of more value than either of these foods fed separately.

5. The inclusion of bran in chick feeding mixtures would appear to be justified on dietetic grounds, in spite of its relatively poor value measured by digestibility trials.

6. From a biological standpoint, bran and bran-weatings mixtures appear to be definitely superior to wheat itself when used exclusively as a source of food and supplemented with 1·5 per cent cod-liver oil and 2 per cent oyster shell.