The development of a community may rightly be said to be reflected in its meat requirements. Primitive peoples are quite satisfied as long as their bulk needs are met, irrespective of quality. This condition may fairly be said to be representative of most of Africa today. A more developed community demands meat of high quality from young and properly finished animals, and this is the I'equirement of the European and emergent African communities, a steadily rising demand which must be met from within the Continent if possible.

Part I described the growth of Angoni cattle as shown by changes in live weight. This Part deals with proportional growth as shown by linear growth and carcass characters.

LINEAR GROWTH

A virtually complete summary of the basic work on linear growth has been given by Brody (1945) and specific references will therefore be quoted only as required for discussion.

1. Evidence is given of an association between the two loci governing inheritance of haemoglobin type and erythrocyte potassium concentration in Welsh Mountain sheep.

2. In the 1777 animals examined, there was an excess of high potassium types amongst carriers of the haemoglobin B gene.

3. At both high and low levels of potassium, sheep possessing haemoglobin A only had significantly more potassium in their blood than animals possessing haemoglobin B only. AB heterozygotes were intermediate in. value.

A population of 1549 Welsh Mountain sheep, typed for haemoglobin and blood potassium concentration, were examined for correlations with production traits.

The statistical analysis was carried out within years, to avoid seasonal effects, and constants were fitted for sire, parity of birth and sex, as well as for haemoglobin and potassium type.

Few of the associations dependent on haemoglobin and potassium level reached significance at generally accepted levels of probability but an underlying consistency existed in mean values. Generally, animals of LK phenotypes showed marginally better neo-natal growth than HK phenotypes and animals possessing haemoglobin A had greater fleece-weights than those which did not.

1. A feeding trial has been carried out with sixty-four individually fed Large White pigs offered eight different diets prepared at four energy levels and two levels of crude protein. A record was maintained of the rate of live-weight gain and food was given at a defined restricted level. Carcass quality was assessed by a procedure of complete dissection into visible fat, lean, etc.

2. Though differences in the rates of live-weight gain and food conversion efficiency were not statistically significant, the best performance was recorded when the diets contained 16 % crude protein and yielded the equivalent of 2950 kcal. digestible energy per kg. upon oxidation. The energy: lysine ratio (kcal. digestible energy per kg. per unit percentage lysine in the ration) was approximately 3500.

1. The literature on the early weaning of lambs has been reviewed.

2. Four experiments were carried out at the Grassland Research Institute, Hurley, during 1959, 1960 and 1961 on the early weaning of Suffolk x Half-Bred lambs. The technique used involved weaning one of a pair of twin lambs at ages varying from 15 to 28 days.

3. In 1959 oneof each of apair of six twin lambs was weaned on to grass alone at 15–20 days. No losses occurred, but the weaned lambs grew very slowly. The unweaned twin lambs remaining with the ewes (i.e. reared as singles) grew at rates comparable to those of single lambs.

1. Sixty-four Dorset Horn ewes and sixty Half- Bred ewes were X-rayed in the pelvic region at stages of pregnancy between 51 and 110 days.

2. Diagnosis of pregnancy and estimates of the number of foetuses carried were made from the X-ray film.

3. Over the range of gestation stages examined, interpretation of the number of foetuses present was found to be most accurate at stages between 91 and 110 days.

4. An accurate estimation of whether the ewe is pregnant or barren can be made from 50 days onwards.

Six factorial experiments, each lasting 3 years, were carried out to determine the effects of N, P and K on herbage cut five times each year.

Clover almost disappeared with the 87 lb. N treatment and none survived with the 174and 348 lb. dressings. N increased the proportions of rye-grass and cocksfoot in the sward. P had no influence on botanical composition. K usually increased the clover content in the absence of, but had practically no effect in the presence of, N.

1. The effects of seed size in the swede crop on germination, emergence, growth and final yield were studied during the period 1959 to 1962.

2. The germination percentage was similar for all sizes of seed, but the emergence percentage was slightly poorer for ‘large’ and ‘small’ seed than for ‘graded’ seed.

3. Leaf area in the early stages of growth was proportional to the seed size, but as the season advanced the plants from small seed grew at a relatively faster rate than those from large seed, so that at harvest the relative yield difference, although still in favour of large seed, was much smaller than the relative difference in seed weight or seedling leaf area. It was shown that the relatively faster growth rate from small seed was not due to a later onset of inter-plant competition.

1. A male-sterile winter bean, inherited as a simple Mendelian recessive, is described.

2. The sterility gene was shown to be expressed in the cytoplasm of eleven inbred lines of English winter beans, two varieties of English spring beans, six varieties of foreign spring beans and three varieties of broad beans (Vicia faba major). It is concluded that these varieties are unlikely to provide a fertility-inducing cytoplasm which would allow the development of a non-restoring pollinator.

3. Evidence of linkage between three chlorophyll-deficient mutants and the male sterility locus is given and circumstances are outlined by which a suitable marker gene could be employed to assist in large-scale production of hybrid seed.

1. F1 hybrids between inbred lines of winter beans were obtained by roguing male-fertile plants from segregating progenies of a genetic male-sterile line which had been interplanted with a pollinator.

2. In a series of trials the mean yields of many hybrids were significantly higher than those of open-pollinated varieties. Over the 4 years, 1959–62, with trials at three centres in each year, the mean advantages of all hybrids over the two control varieties was 6·4 cwt./acre over Gartons S.Q., 4·7 cwt./acre over Throws M.S.

1. Concentrations of ammonia, volatile fatty acids, and molar proportions of acetic, propionic and butyric acids were determined in the rumen liquor of sheep fed fresh herbage harvested in the first month of growth.

2. Concentrations ofammoniacal nitrogen ranged from 4·06 to 13·65 mg./1OO ml. rumen liquor with a mean value of 8·21.

3. Concentrations of volatile fatty acids ranged from 7·50 to 12·20 m-moles/100 ml. rumen liquor with a mean value of 9·81. Mean molar proportions of acids were: acetic 65·8%, propionic 19·5%, n-butyric 9·0 % and higher acids 5·7 %. Differences in the proportions of acids found at different sampling times were not statistically significant.

Results are given of 124 factorial experiments testing N, P and K fertilizers for maincrop potatoes; the experiments were done by N.A.A.S. Soil Chemists in the years 1955–61. The experimental sites were in sixteen groups, corresponding to particular soil series or complexes.

There were substantial differences in mean yield and in response to the lower levels of P and K between soil series; the influence of soil was less at higher rates of application. Alternative methods of soil classification which appeared to be associated with response were texture, experiments on the lighter-textured soils showing higher responses to K; and depth of freely drained soil, soils with impeded drainage being associated with larger P responses. Responses to P and K were particularly large on soils in Wales and N.W. Cumberland.

Photosynthetic rates of detached, mature tea leaves from four different sources were determined in excess CO2 and light of 4, 10, 16 and 32 klux intensities from a tungsten-filament lamp. Temperature was maintained at 25°C. The assimilation rates were significantly different for the four sources both in weak and in strong light. Neither thickness of the leaf lamina nor chlorophyll concentration could explain the cause of this difference.

The effect of shade adaptation on the subsequent rate of assimilation was examined in one of the four sources of leaf. Shade-adapted leaves had significantly higher rates of photosynthesis at the weakest light intensity of 4 klux and lower rates in 16 and 32 klux intensities than the corresponding sun leaves.

Natural infection by Verticillium albo-atrum occurred in two experiments, one comparing test crosses of inbred parents, the other a complete set of crosses between non-inbred parents. Although the uncontrolled variation was rather large, significant differences between progenies were detected in both cases. The differences were mainly accounted for by differences in general combining ability among the parents but not entirely so in the second experiment.

1. Groundnut meal and herring meal have been compared as protein sources for ruminants.

2. Herring meal caused less extensive formation of ammonia in the rumen than did groundnut meal.

3. Nitrogen-balance experiments showed that herring meal fed to lactating goats was used more efficiently than groundnut meal fed under the same dietary conditions.

4. Herring meal was superior to groundnut meal for milk production in dairy cows.

1. Groundnut meals subjected to different degrees of heat treatment during manufacture were fed to lactating goats on nitrogen-balance experiment. The ‘toasted’ groundnut meal was more effective than undenatured or air-dried meals in promoting nitrogen retention.

2. The heat treatment of the groundnut meals did not influence the digestibility of the protein.

3. The groundnut meals were typed by determining their salt-peptizability giving values ranging from 44% for the ‘toasted’ meal to 80% for the air-dried meal.