(1) Distinct changes take place in the tissues of the mammary region in sows during the period of heat. These changes consist mainly of congestion of the glands. Moreover the part affected is in the pig of much commercial value.

(2) The black pigment often found in the mammary tissue of black sows is not associated with the recurrence of heat, and the bacon manufacturer who wishes to differentiate between sows slaughtered at this period and other sows must not rely on this pigment as a guide.

(3) Since ovulation occurs during oestrus and not during prooestrum it is advisable to “hog” the sow towards the end of her heat period.

Data concerning a random sample of flocks in Yorkshire and Lancashire were collected, in the form of answers to a questionnaire. Information was received from 88% of the 272 farms approached.

The present survey, a more detailed repetition of one performed in 1952–53, has extended the information already collected and enabled deductions to be made regarding the relationship between disease losses, breed and husbandry methods. The advantages and disadvantages of this type of survey are discussed.

1. Two series of simple nitrogen manuring trials, one on level of sulphate of ammonia applied to the seedbed at twenty-two centres and the other on the time of top dressing with ‘Nitro-Chalk’ at nineteen centres, were conducted on commercial farms in south-east Scotland during 1954 to 1957.

2. The optimum level of sulphate of ammonia varied with season and farm type. The optimum dressing was at least 0·9 cwt. N/acre in the dry season of 1955, and in the other years was estimated to be 0·9 cwt. N/acre on arable farms and about 0·-25–0·4 cwt. on ley rotation farms when the barley did not follow sheeped turnips. In the latter event no fertilizer was best.

3. The nitrogen content of the grain increased little until after the 1 cwt. sulphate of ammonia level, although the optimum yield was not obtained in many experiments without some rise in the grain nitrogen content.

1. A study has been made of the relative development of some regions in the fleece of twin lambs of a Suffolk ♂ × Suffolk (Border Leicester-Cheviot) ♀ cross during growth. The different regions develop in the following order: shoulder → leg → belly → tail. It is concluded that an improved animal is one in which the latest developing part of the fleece has the least possible number of undesirable fibres at the earliest possible age. The breeds of sheep begin their wool improvement by changes in the earliest developing regions (shoulder) and finish it in the latest (tail).

2. The properties of the fleece studied were the colour of the fibres, the medullated fibres, the fineness of the fibres, and uniformity of fibre size. In general a relationship is found between the stage and rapidity of development of the area, and the properties of the fibre. The intensity of the colour is stronger during the early active stages of development. There is a tendency to lose some kinds of coloured fibres, and to diminish the intensity of the colour in others as the development of each region in which the fibres grow proceeds.

The medullated fibres appeared in greatest quantities in the later developing regions, except the belly which presents few medullated fibres.

The staple is much finer at the first month of growth than in the later stages. Frequency curves of fibre size are of more value than average fibre size in estimating the value of the fleece.

3. It is suggested that the examination of the fleece of the lamb will give some idea of its genetic constitution and will reveal defects which would be concealed in the adult. Such a “phaeno-genetic” selection can be made best in a “late developing” area of the body such as the tail of the lamb at one month old.

An experiment designed to show the effects of a complete fertilizer and of water applied extra to the rainfall on the yield of carrots grown on a gravel soil in good heart, has demonstrated that the fertilizer mixture was entirely without effect. The interaction water level × fertilizer was not significant, so that the increases in yield of carrot roots (increases which were 61·46 and 127·5 ― above the mean of the plots for rainfall only in the case of the total crop, and 61·73 and 111·5 ― for ware carrots, for 3 and 6 in. of water extra to the rainfall, respectively) were due entirely to the additional water. The response in yield of the roots of the total crop and of ware to the second application of extra water showed no falling off compared with the response to the first extra application. There was evidence to prove that additional water caused heavier infestation of the roots by aphis.

Two sets of experiments were carried out to compare methods of selecting Festuca arundinacea (tall fescue) for improved seedling vigour.

In the first, germination and seedling growth of four varieties (Goar, Lironde, S. 170, and ZW 42–6) were compared in hydroponic growth tanks. From each variety, groups of seedlings were selected for each of four vigour characters (speed of germination, leaf length, root length and speed of production of the second leaf) and a fifth group was selected at random as a control. Plants of each group were intercrossed in isolation and their progeny compared.

In the second, S. 170 was studied through two cycles of selection in a soil-based compost. In the first cycle, groups of seedlings were selected for each of five characters (speed of emergence, leaf length, and speed of production of the second leaf, first axillary tiller and coleoptile tiller). Two further groups were selected randomly. In the second cycle, the progeny of each group were reselected for the same character as their parents. Both first- and second-cycle progeny were compared among themselves.

Significant direct responses to selection were obtained in all characters except speed of germination in hydroponics. Indirect responses also occurred but were mostly smaller and in response to selection for a related character, e.g. selection for early tillering resulted in early second leaves and vice versa. Two cycles of selection raised the frequency of coleoptile tillers from about 5 to 55 %, but the concomitant advances in vigour characters were smaller than those achieved by direct selection. It is argued that for practical purposes the basic criterion in selecting for improved seedling vigour should be rapid attainment of a particular growth stage such as appearance of the first tiller. Since speed of emergence itself responded to selection, the attainment of such a stage should be related to date of sowing rather than of emergence or germination.

In the progeny of the hydroponic selections, all characters showed significant varietal differences, some of them the reverse of differences between the parent populations of the varieties. These results illustrated the importance of seed provenance as a determinant of seedling vigour, and suggest that choice of parent material is important in breeding for improved vigour.

1. The effects of the addition of a non-ionic, anionic or cationic detergent to a diet containing 10% added fat on the digestibility of the protein, fat and carbohydrate have been studied.

2. The non-ionic detergent aided the digestion of fat, but protein and carbohydrate digestibility were unaffected.

3. An anionic detergent slightly, and a cationic detergent seriously, impaired the absorption of fat, and the cationic detergent also had an adverse effect on carbohydrate digestion. Neither affected protein digestion.

The aim of the research was to describe and characterize the physiological basis of Mn use efficiency among a range of old and modern UK wheat cultivars grown in Mn-depleted solution culture and to ascertain whether the existence of Mn use efficiency conferred a yield advantage under manganese stress conditions in the field. Results of solution culture experiments demonstrated that the old spring wheat cv. Maris Butler is relatively Mn efficient when grown in Mn-deficient conditions in comparison with both a modern winter wheat, cv. Claire, and a modern spring wheat, cv. Paragon. The mean dry weight gain of plants of cv. Maris Butler grown in Mn-depleted nutrient solution was 0·49 of that shown by plants in Mn-sufficient culture, whereas in cvs. Paragon and Claire the equivalent values were 0·38 and 0·21 respectively. When grown in Mn-deficient soil in a farm-based field trial, cv. Maris Butler showed significantly improved (P<0·05) dry matter accumulation and grain yield compared with other spring wheats including cv. Paragon. There was no significant variation in leaf Mn content between the cultivars examined, either under sufficient or depleted Mn supply; however, cv. Maris Butler showed both a relatively high maximum light-saturated rate of photosynthesis and a high photosynthetic apparent quantum yield (based on O2 evolution) when grown under Mn deficiency. It is argued that the apparent Mn use efficiency of cv. Maris Butler is related to superior internal utilization of Mn, resulting in an increased photosynthetic photosytem II efficiency rather than improved Mn uptake and accumulation. The results suggest that the wheat cultivar Maris Butler may provide a potentially useful source of parental material for future crop improvement programmes designed to produce wheat lines resistant to depleted Mn supply.

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.

Compositional analysis of feeds and other materials by near-infrared reflectance (NIR) has been proposed as a cheap and rapid alternative to traditional wet chemical methods. A theoretical basis for NIR measurements is needed and may be obtained from the study of artificial mixtures of pure chemicals.

Mixtures of lactose, casein and sodium oleate, in widely differing concentrations, were analysed by NIR. Principal component analysis was used to study the variations between spectra, and multiple linear regressions gave predictors of sample compositions from the spectra. Optical densities at most combinations of wavelengths gave good predictions of sample compositions because there was much less unexplained variation between NIR spectra than would occur between natural samples.

Much work has been done with regard to the elements necessary for plants, their function in the plant, methods of absorption, amounts necessary, nutrient solutions, etc. The following is particularly, concerned with nutrient solutions, including their composition, concentration, methods of application, and the general methods of dealing with sand and water cultures. The work is confined mainly to a study of the major elements.

A total of 1180 1-day-old Japanese quail (Coturnix japonica) chicks were used to investigate the effect of feathering rates on growth and slaughter traits. Feathering rates were classified based on the results of stepwise regression using numbers and lengths of both primaries and secondaries and tail length at 7 and 10 days of age as predictors. At 7 and 10 days old, number of primary feathers had phenotypically positive low correlations (rps) with body weight (BW), whereas number of secondaries had positive medium rps with BW at different ages. Lengths of primary, secondary and tail feathers had highly positive rps with BW traits at different ages. Results of stepwise multiple regressions indicated that BW at 14, 21 and 28 days of age can be predicted using lengths of secondary and tail feathers at 10 days old, number of secondaries at 7 days old and length of secondaries at 7 days old, respectively. Body weight at 35 days of age can be predicted using number of primaries, lengths of secondaries and tail at 10 days of age and number of secondaries at 7 days of age. Higher BWs were obtained in the fast-feathering class from 21 up to 35 days of age than in other groups, whereas the slow-feathering class had the lowest BW. Significant class differences were found for carcass weight, feather weight and dressing% favouring the fast- over the slow-feathering class. Therefore, early feathering rates improved BW at later ages and slaughter traits in Japanese quail.

In a previous paper (Davies, 1926) the author studied the differences in the compositions of protoplasmic proteins of plants within a Natural Order (Leguminosae). The Natural Order Cruciferae afforded a means of developing the study in the direction not only of ascertaining differences, if any, of protoplasmic protein of plants within a genus, but also of differences possible within a species. Thus proteins were studied from the following varieties of the cabbage species (Brassica oleracea L.): Cabbage (B. oleracea var. capitata), Marrow stem kale (B. oleracea var.) from the stems and leaves separately, Kohl rabi (B. oleracea var. caulorapa). Also, the proteins from the leaves and roots respectively of white turnips (B. napo-brassica) were isolated and studied. In order to compare the protoplasmic proteins with those of seed of a plant of the same species, a globulin from rapeseed (seed of Brassica Napus L.) was prepared and analysed.

A half-diallel design, with parents, involving a random sample of nine partially inbred (S1) lines was used to examine the genetic control of bolting in a broad-based North-West European sugarbeet breeding population. The diallel was analysed using the Hayman (1954a) and Jinks & Hayman (1953) analyses. Additive genetic effects were shown to be highly important and significant dominance effects were found. A general trend for bolting resistance to be dominant was detected but there was also evidence that the control was ambidirectional. Furthermore, the dominance effects seemed only partially effective. Some indication of epistatic effects was found, although the possibility that this was spurious, caused by failures in the genetic assumptions required by the analyses, is discussed. The genetic control of bolting in the breeding population appeared complex.

The experiments described below have been carried out to confirm some results obtained by F. Löhnis, who made it appear highly probable that soil bacteria were concerned in rendering calcium cyanamide assimilable for crops. It had been supposed that the reaction of calcium cyanamide in the soil was a purely chemical one. The material used was taken from a supply of “Kalkstickstoff” received at the Rothamsted Experimental Station from the “Cyanid Gesellschaft” of Berlin early this year. Nitrogen determinations by the Kjeldahl method showed the crude fertiliser to contain 20.3 per cent, nitrogen, equal to 58 per cent, pure calcium cyanamide.

An experiment is described in which four pairs of individually fed identical twin calves were used to investigate the effects of castration at 1 and 7 months, on growth, efficiency of food utilization and carcass composition and conformation.

The results indicate that up to 28 weeks of age the late-castrated animals wore superior in liveweight increase, width of head and efficiency with which they converted food to live weight. By slaughter time, at about 18 months, these differences, except width of head, had been eliminated.

The carcasses from both treatments were very similar except that a slightly greater percentage of the total muscle occurred in the thoracic and abdominal muscles of the late-castrated animals than in the early-castrated ones. A statistically significant higher percentage of the total fat occurred as subcutaneous fat in the late-castrated animals than in the early-castrated ones.

The gradual loss of efficiency of certain alkaline arsenite dipping baths has been traced by Brünnich to the oxidation of the arsenite to arsenate (Australian Association for the Advancement of Science, 1909). In this latter form, arsenic is not nearly so efficacious for the eradication of ticks, as in the reduced condition.

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

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

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

1. A sample of marine silt taken from the foreshore of the N.W. coastal belt of the Wash was found as the result of a mineralogical examination to contain dolomite in its mineral assemblage.

2. It was surmised from this discovery that should dolomite be a normal constituent of soils derived from marine silts, its presence might modify in them certain processes such as nitrification in which the neutralising effect of a quick acting base is an essential factor.

3. This supposition was strengthened by certain culture experiments on nitrification, and was to some extent established as a fact by a detailed chemical investigation into the nature of the carbonate content of several soils of known geological and agricultural history.

In three factorial growth experiments and a metabolism experiment pigs of approximately 25 kg initial live weight were given on a restricted scale of feeding simple diets, based on barley, a vitamin and mineral supplement and either soya-bean meal (SBM) or a low glucosinolate rapeseed meal (cv. Tower; TRSM). Variations in these two basic diets were produced by adding different quantities of tannic acid, polyethylene glycol (PEG) and copper (Cu).

Diets based on soya-bean meal were used in the first experiment. There were no significant interactions. Tannic acid added at 3·75 and 7·50 g/kg air-dry matter was without significant effect on performance compared with no tannic acid addition, but PEG at 17 g/kg air-dry matter significantly improved growth rate compared with no PEG addition to the diet (P < 0·05). In the second experiment TRSM-based diets were used. There were no significant interactions and no significant effects on performance from adding 0, 8·5 and 17·0 g PEG/kg air-dry matter. Increasing Cu from 17 to 54 mg/kg air-dry diet significantly improved growth rate (P < 0·05). In the third experiment TRSM and SBM based diets, of similar digestible energy (DE), crude protein and lysine content, and containing either 19 or 202 mg Cu/kg air-dry matter, were used. Pigs were slaughtered at 87·5 kg live weight and hand joints dissected. Pigs given the TRSM diet containing 19 mg Cu/kg grew significantly more slowly than pigs given the three other diets between which there were no significant differences. There were no other significant interactions and no significant differences between Cu concentrations for the growth, carcass and efficiency of conversion results. Compared with TRSM diets, SBM diets at similar slaughter weights gave significantly greater carcass weights, killingout proportions and backfat thicknesses. Also the efficiencies with which dietary protein and DE were used to promote units of carcass growth were significantly better for the SBM diets, but there were no significant differences in the estimated weights of lean in carcasses.

In the metabolism experiments the effects of adding PEG to diets similar to those used in the growth experiments were examined. The apparent digestibilities of dry matter, gross energy and nitrogen and the nitrogen retentions were significantly greater for the SBM diets than for the TRSM diets. The addition of PEG to the SBM and TRSM diets significantly decreased the apparent digestibilities of dry matter and gross energy, and significantly increased the apparent digestibility of nitrogen in the SBM diet but not in the TRSM diet.