In twenty-nine experiments conducted in 1945, 1946 and 1947 placement of fertilizer in contact with the seed or in two bands each 2 in. away and 2 in. below the level of the seed gave average yields similar to those given by the standard practice of broadcasting after ridging but before planting. Placement in one band 2 in. below the seed was tested in four experiments and proved inferior to other placement methods and to broadcasting over the ridges.

1. Losses in carotene from fresh grass have been studied during the operations of wilting and drying and from bales of dried grass and dried grass meal during storage.

2. With good management wilting and drying need cause only 15–20% reduction in the carotene content of the fresh grass. In fine, sunny weather field wilting is likely to cause serious loss, and the period of wilting should not exceed 2–3 hr.

3. Production of dried grass meal by efficiently run commercial driers is unlikely to cause more than 5–10% loss in carotene content, whereas during storage for 6 months 30–40% of the carotene initially present in the dried product may be lost, depending on the temperature.

4. Exposure of the dried grass to sunlight quickly bleaches it, but carotene losses due to photochemical action will be confined to a thin surface layer.

1. It has been shown in a previous paper (Callow, 1948) that, with ‘standard’ carcasses of cattle, sheep and pigs containing more than 18 % of fatty tissue, FT/C, there is a close correlation between FT/C and MT/C, the percentage of muscular tissue. This is shown by the linear regression equation

MT/C = 76·1 — 0·684FT/C ± 1·0 (r= — 0·9782).

The reasons for this close correlation and the effects of varying rates of fattening on the constants of the generalized equation

MT/C = a — bFT/C

have been deduced by a mathematical and biological analysis of the data.

A study has been made of the extraction of organic carbon and nitrogen from soil by various inorganic reagents. The results show that the organic carbon and nitrogen of soil are so intimately associated that, under the influence of any one of the reagents tested, the organic carbon is dissolved only along with, and in proportion to, the organic nitrogen. The relative proportions of carbon and nitrogen extracted vary, however, with both the soil and the extractant.

A suitable modification of the microbiological method for assaying pantothenic acid was developed and the pantothenic acid content in various kinds of poultry-feeding stuffs determined by its use. To assure quantitative liberation of the total amount of the pantothenic acid from the samples it is recommended to digest the samples first with Clarase.

Pantothenic acid content was determined in poultry feeds of animal origin, such as fish-meal, meat-scrap, liver-meal and different kinds of milk-powder. It is remarkable that different kinds of fish-meal differ markedly in their pantothenic acid content.

Fertilizer placed in contact with the seed damaged the germination of sugar beet, mangolds, swedes and peas in 1947; damage was also caused by fertilizer placed directly below the seed. In 1947 and 1948 some damage to the germination of sugar beet was caused by fertilizer in bands 3 in. below the soil surface and 1 in. to the side of the seed; in both years bands of fertilizer 3 in. to the side of the seed were safe. Where placement of medium or full fertilizer dressings is adopted for row crops, the bands should be placed not less than 2 in. from the seed to avoid the risk of injury to germination.

All methods of placing gave consistently higher yields of peas than broadcasting fertilizer, the average advantage of placing being over 2 cwt. of peas per acre. In all the experiments on peas in 1948 early applications broadcast and worked deeply into the seed-bed were somewhat superior to late applications made at sowing time.

1. The acid hydrolysis of six soils with nitrogen contents ranging from 0·1 to 2·38% has been studied by determining the amounts of ammonia-, humin- and α-amino-N present in the soil hydrolysates after various periods of hydrolysis.

2. Under the conditions of hydrolysis employed (3 ml. of 6N-HCl/g. soil) the period required for maximum liberation of amino-acids from the soils was about 12 hr. 24·2–37·1% of the total-nitrogen of the soils examined was liberated as α-amino-N in this period. Further hydrolysis led to destruction of amino-acids. Similar amounts of α-amino-N were liberated by hydrolysis of the soils with alkali (5N-NaOH).

3. From 69 to 87% of the total-nitrogen of the soils was brought into solution by acid hydrolysis; the amount dissolved by hydrolysing with alkali or with alkali under reducing conditions (alkalistannite) was not significantly different. It is concluded that most of the insoluble-nitrogen found after acid hydrolysis is not derived from protein material, and it is suggested that some of this nitrogen is in the form of heterocyclic nitrogen compounds.

When growing Cheviot hoggs were wholly maintained indoors on a very poor quality hay fed ad libitum they had a low food intake and consequently were losing weight. A 40 g. supplement of ‘Fodder Yeast’ greatly increased the hay intake of the sheep, and this was accompanied by a steady gain in body weight. Increase in body weight appeared to be accountable for by the increase in food consumption. These findings, obtained in a pilot experiment, require confirmation with a larger flock of sheep.

1. The object of this investigation has been to advance knowledge of the methods necessary for the practical application of the transplantation of fertilized ova in cattle.

2. The induction of ovulation at any specific time can be produced by squeezing out the corpus luteum per rectum. Oestrus occurs from 2 to 4 days afterwards; this is accompanied by ovulation and the ova so produced are readily fertilized. The onset of oestrus after the expression of the corpus luteum is hastened by previous treatment with P.M.S.

3. The induction of multiple ovulations is necessary to produce an augmented supply of fertilized ova, but it is of primary importance that the ova so produced are fertilized, viable and capable of full development. Four methods of doing this have been tested.

In this study samples of the mixed milk from a herd of sheep were taken weekly for analysis throughout a season of approximately 7 months. The following are the mean values obtained: sp.gr. 1·0350, S.e.m. 0·0002; acidity 0·226%, S.e.m. 0·003; fat 8·00%, S.e.m. 0·07; S.n.f. 11·35%, S.e.m. 0·06; and total N 0·920%, S.e.m. 0·007.

Samples were also taken at 2-week intervals throughout the lactation period of six individual ewes of the Rahmany breed and of the same number of the Awsemy breed. The variation in the composition of their milk throughout lactation and also the variation due to individuality are discussed.

1. The bacteria commonly found in freshly collected fowl semen are coliform bacilli, staphylococci, diphtheroid bacilli and haemolytic streptococci. These organisms are probably derived from the cloaca, which usually has the same flora as the expressed semen, while the sperm mass from the vas deferens is sterile.

2. In diluted or undiluted semen stored for 24 hr. at room temperature, or 48 hr. at 2°C, there is a great increase in the bacterial population, especially of coliform bacilli.

3. Although the presence of egg white did not diminish the growth of bacteria in stored diluted semen it improved the motility of the spermatozoa.

4. Sulphathiazole in the concentrations used proved toxic to the spermatozoa, and unreliable for bacteriostasis.

1. Nine pig-rearing experiments designed to probe the causes of ill-health among young pigs farrowed and reared indoors suggested that the main cause of trouble was that the buildings were too cold, draughty and damp.

2. The superior health of pigs farrowed and reared outdoors appeared to depend less on their access to iron or unknown nutrients in soil and grass than to the greater comfort afforded by the wooden ark huts in which they were housed.

3. The clinical and pathological features of sick indoor pigs were essentially those of cardiac failure.

4. In a discussion of our own findings and the published reports of others we offer a working hypothesis to explain the sequence of events. We hope to explore its validity in future experiments.

Work on this subject was suggested by Mr Arthur Crichton and encouraged at all stages by his interest and advice.

The activity of spermatozoa in bull semen can be assessed by measuring the frequency of impedance changes in the semen. Such measurements necessitate the passage of a small electric current through the semen. The field experiment described in this paper shows that this electrical treatment is harmless. Measurements can therefore be made on samples of semen which subsequently will be used in artificial insemination.

The Journal of Agricultural Science

Vol. 38, Part 3

July 1948

Page 323

Fructose Content and Fructolysis in Semen. Practical Application in The Evaluation of Semen Quality

By T. Mann, Molteno Institute, University of Cambridge

The last sentence on p. 323 at present reads as follows: “0.25M phosphate buffer pH 7.4, prepared by dissolving Na2HPO4 (or Na2HPO4. 12H2O) in 190 ml. glass distilled water and adding 10 ml. IN-HCI.”

1. Seven matings in which there were sperm survival times of 66–76 hr. in a mixed group of pony mares resulted in seven pregnancies. Of six matings with an interval of 90–100 hr., five proved pregnant. One mare, mated with an interval of 126–138 hr., also became pregnant.

2. Where pregnancy urine extract is injected to bring about ovulation, the injection-ovulation interval can be accurately forecast at 40–48 hr. If the interval is longer the follicle was not sufficiently advanced to warrant injection, if shorter the follicle would have ovulated naturally in the same time.

A general account of investigations carried out at the Plant Breeding Institute, Cambridge, on winter oats was published by Hunter (1935). In it brief mention is made of the origin of a series of oats designated the ‘ex 109/1 series’. It is the purpose of this article to give a more detailed account of the origin and behaviour of this series, from which the winter variety Picton was selected, and to detail a further number of anomalous features which have arisen in the course of breeding work at Cambridge.

An adapted animal is one in perfect harmony with its environment. Of all the interrelated factors influencing the environment, climate is probably the most important, affecting not only the vegetation and parasitical fauna but likewise the density of human population, its needs and culture.

A study of the climatological influence on animals must be comprehensive and include species, breeds and types within breeds, land as well as aquatic animals, both steppe and mountain animals, and existing animals as well as those of historical importance. The climatology with which the animal breeder is concerned aims at establishing the influence of climate, with its constantly recurring phases, upon the animal (in this case the bovine). The reaction of any animal to a particular external environmental stimulus is closely correlated with the animal's efficiency of production.

Samples of bracken were taken at regular intervals between June and October from a hill grazing where losses of cattle from ‘bracken poisoning’ had occurred in previous years. These were separated into leaf and stem for analysis. Dry, mature bracken cut in October was examined for digestibility and nutritive value, and in the following season the digestibility of fresh, green bracken was determined for both cattle and sheep.

Chemical composition. Analyses of the fresh bracken fed in the digestibility trials were in line with those of the samples collected in the previous year. Crudeprotein content was high in June and July, but fell markedly in August and September, whilst the crude fibre varied in the opposite direction, increasing markedly in August. An increase in the tannin content was observed in September but this was not comparable with the increases reported by Shearer. An attempt to elucidate the significance of tannin in the in vitro digestion of bracken-leaf protein was unsuccessful. The potassium content was found to be rather lower than in good pasture grass, confirming the findings of Ferguson & Armitage. The potassium was highly soluble in water but the soluble part was not entirely in the form of chloride.

The records of the Home-Grown Wheat Committee, set up in 1901 by the National Association of British and Irish Millers, whose work continued up to 1938, dealt in the main with the trial of wheat for baking strength. Nevertheless, references to milling character were occasionally noted; for instance in 1923, Sir Albert Humphries, writing of his twenty-year trial on Red Fife wheat in England, states ‘Each lot, including those originally of very high moisture content, was found to possess the free milling characteristics of Manitoba wheat. … Stated differently, it may be said that each lot behaved in milling very differently from average English wheats, excluding Yeoman.’