Using microbiological methods, thiamin, riboflavin and niacin have been determined in individual milk samples taken from a number of ewes at intervals during their lactation. Although considerable individual variations were found, the average values of 0.67μg./ml. for thiamin, 5.68μg./ml. for riboflavin and 4.80μg./ml. for niacin in New Zealand ewes' milk are somewhat higher than those reported by overseas workers. No lactational effects are apparent from the results presented.

A new, rapid method for the determination of cellulose has been investigated, and has been shown to yield a fraction composed mainly of hexosan. The method has been shown to be applicable to feeding-stuffs and faecal material, with a satisfactory degree of accuracy.

Three methods for the determination of cellulose have been compared for their value in nutritional studies, and have indicated the applicability of the procedure of Druce &Willcox (1949) in this connexion.

The use of the method of Crampton & Maynard (1938) has been shown to give an erroneous picture of the extent of cellulose digestibility, and it has been concluded that the procedure is not satisfactory.

1. Records of mortality of Dairy Shorthorn heifer calves in the N.I.R.D. herd from 1924 to 1946 were analysed and show a total loss of 16·3%. Losses due to abortions amounted to 5·1%, to stillbirths 6·3%, and post-natal losses in calves up to 6 months of age, 4·8%.

2. The mean adjusted length of gestation period for 230 Dairy Shorthorn cows was 285·6 days.

3. Calves carried longer were heavier at birth, the average increase in weight amounting to 0·91 lb. per day of gestation.

4. The adjusted mean birth weight of the calves was 81·68 lb. Bull calves are carried longer than heifer calves by about 1·68 days and they are heavier at birth by about 3·29 lb.

5. The birth weight of 111 heifer calves born between 1940 and 1947 was 79·9 lb. as compared with the value obtained before the war of 87·0 lb. for 285 heifer calves.

Some factors affecting the weight of the calf at birth were studied; including the effect of artificial mating.

An analysis of the breeding of 130 kinky-tailed pigs of Large White and Wessex origin indicates that the character is genetic in nature and is of variable penetrance and expressivity. The hypothesis is put forward that pigs, in general, may be charcterized by a slight tendency to this defect which is exhibited when the appropriate accidents of development occur. In addition, there may be genes which raise the overall frequency and severity of the defect. In the Large White inbred strain studied, it is thought that there were minor genes with a recessive effect as well as a major gene with incomplete dominance. In the inbred strain several litters were obtained which included no normal pigs although both parents were apparently normal. In outcrosses, kinky tails appeared less frequently. Inbred, kinky-tailed pigs were difficult to rear and of those kept for breeding most proved sterile. Post-mortem examination of a number of affected pigs showed a high incidence of abnormalities of the kidneys, ureters and genitalia. The suggestion is made that kinky tails are but a minor manifestation of an early developmental disorder.

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. 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.

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. 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.

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.

Cows were treated with various doses of pregnant mare serum gonadotrophin given either towards the end of the normal cycle, or prior to expression of the corpus luteum. The animals were kept under normal farm conditions; the object of treatment was to obtain twin ovulations and calvings.

Some success was achieved, but of the treatments tried none could be considered commercially worth while; many variants of treatment are possible and much more requires to be done. For practical application it is important that a treatment should not, or only rarely, result in more than three ovulations. The few cows reported in this paper which were pregnant and which had more than three corpora lutea aborted at about 5 months.

This work was carried out from the School of Agriculture, Cambridge, during tenure of a grant from the Agricultural Research Council. It was possible only through the help of those farmers who provided animals for experiment; I here record my indebtedness to them.

1. A study has been made of the effect of conditions of growing and of maturity on the concentration of total carotenoids (t.c.) in the root of the carrot, Daucus carota L.

2. Carotene comprised nearly 90% of the total carotenoids in all categories of carrot roots except the very small seedlings. Hence t.c. concentration may be used as an index of carotene concentration.

3. In order to develop their full t.c. concentration by autumn, carrot varieties with normal t.c. values must be sown before the end of May. High-carotene varieties must be sown at least a month earlier. ‘Stecklings’ grown from summer-sown seeds and examined in spring had only about a third of their fully mature t.c. value.

Milk production is of fundamental and practical importance to the sheep industry. Reports indicate considerable differences in milking ability between ewes of different breeds as well as between ewes of the same breed.

Milking capacity of ewes is dependent on both nutritional and hereditary factors, probably the nutritional factor being the more important. Under commercial farming conditions milk yield might affect not only the growth rates of ‘fat’ lambs and the quality of their carcases, but eventually also the constitution of the ewe lambs retained in the flocks for breeding purposes. It therefore appeared that milking ability of Romney ewes in New Zealand would be a matter worthy of investigation.