Live-weight gain of beef cattle grazing all-grass or grass-clover pastures, details of which have been reported previously, was significantly (P < 0·01) correlated with pasture growth rate, but not with pasture dry matter on offer (either total or green), or with dietary-energy concentration. From ideas generated from the relationship between live-weight gain and pasture growth rate, and using intake values measured from the number and size of prehension bites, it is shown how high live-weight gain for measured dietary-energy concentration could be explained by differential contribution to digestibility and voluntary intake from pasture new growth.

The present paper is an account of observations and experiments in connexion with Silver-leaf Disease which have been made since the publication of my paper on the same subject in the Journal of Agricultural Science for 1911. I am indebted to the Board of Agriculture for giving a grant to assist this work and to the Cambridge University School of Agriculture for placing at my disposal a plot of land on its farm for most of the fruit trees used in the experiments. I have also to thank Mr R. I. Lynch, Curator of the Botanic Gardens, Cambridge, for providing accommodation for other trees.

An investigation on the different environmental and genetic causes of variation in the birth weight of Black Bengal goats was conducted at the Central Livestock Research-cum-Breeding Station, Haringhata, India. The data consisted of 1375 birth weight records of kids from 284 does and 20 bucks during the period from 1955 to 1961. The goats were maintained under standard farm management throughout the period.

Year had significant effect on birth weight, while the effect of season was insignificant. The interaction was, however, significant. Male kids were significantly heavier at birth than the females. Age of dam and litter size also caused significant variation in birth weight of kids.

From paternal half-sib analysis the heritability of birth weight was estimated to be 0·01. Full sib and maternal half sib analyses estimated the maternal environment common to litter mates to account for 60 % of the variance, out of which 25 % were due to permanent differences between dams. The remaining 39 % were attributed to individual environment, including most of the non-additive genetic variance. The heritability of maternal environment was estimated to be 0·2.

The partial correlation coefficient between birth weight of kids and post-kidding body weight of their dam, independent of litter size and age of dam, was 0·175. Thus, body size of dam, as indicated by post kidding body weight, did not reveal much information about maternal environment.

The work undertaken in 1922 was in the main a continuation of that done in 1920 and 1921, the results of which have already been published, and the object of which had been to determine the relation between the size of the seed tuber-sets and their resultant crop, and the further relation between the amount of heavy ware in the crop and the size of the seed.

Copy number variations (CNVs), as an important source of genetic variation, can affect a wide range of phenotypes by diverse mechanisms. The somatostatin receptor 2 (SSTR2) gene plays important roles in cell proliferation and apoptosis. Recently, this gene was mapped to a CNV region, which encompasses quantitative trait loci of cattle economic traits including body weight, marbling score, etc. Therefore, SSTR2 CNV may exhibit phenotypic effects on cattle growth traits. In the current study, distribution of SSTR2 gene CNVs was investigated in six Chinese cattle breeds (XN, QC, NY, JA, LX and PN), and the results showed higher CNV polymorphisms in XN, QC and NY cattle. Next, association analysis between growth traits and SSTR2 CNV was performed for XN, QC and NY cattle. In NY, individuals with fewer copies showed better performance than those with more copies. Further, the effects of SSTR2 CNV on the SSTR2 mRNA level were also investigated, but revealed no significant correlation in either muscle or adipose tissue of adult NY cattle. The results suggested the potential for use of SSTR2 CNV as a marker for the molecular breeding of NY cattle.

The discovery that partial sterilisation by heat is capable of greatly increasing the fertility of the soil, opens up possibilities full of interest both to agriculturist and to horticulturist. Steaming the soil has already become a common practice by growers of tomatoes under glass, where the soil in the houses when “sick,” that is, infertile no matter how heavily manured, is treated with steam, whereby its fertility is completely restored.

Rapeseed and mustard crops are the second most important source of edible oil after groundnut in India. The average yield of these crops is around 600 kg/ha which has been static for several years. These low yields are of increasing concern in view of the short supply of oil seeds in India. Considerable breeding efforts are being directed to improving production potential as well as stability of yield in these crops (Prakash, 1980). An understanding of the physiological basis of yield formation can be of great help in selecting for high and stable yields. However, there is little information available on the production physiology of these crops (Mehrotra, Saxena & Moosa, 1976; Bhargava & Tomar, 1982).

Six hundred and sixty-two sheep in twenty-two farm flocks were treated in June/July (period of late anoestrus) with intravaginal sponges impregnated with 30 mg ‘Cronolone’ (9α-fluoro-11β-hydroxy-17α-acetoxy-progesterone; G. D. Searle) or ‘Cronolone’ plus 400 mg progesterone and incorporating doses of 0-800 μg oestradiol-17β. Treatment was for 12 days; a single dose of 500 i.u. PMS (Burrough's Wellcome) was injected at pessary withdrawal. Seventy rams were joined to breed the ewes at first and second heats.

Oestradiol treatment resulted in a significantly higher incidence of sponge loss, a lower mating response, a lower conception rate and a lower number of lambs/conception. There was also a tendency for onset of oestrus to be delayed. Such effects were confined to first services and were much less evident in sheep receiving doses of 50 μg oestradiol or below. Data indicate that an intravaginal treatment for the induction of early breeding should consist of progestagen alone rather than progestagen in combination with oestradiol. The addition of 400 mg progesterone to the ‘Cronolone’ sponges appeared to reduce the adverse oestrogenic effects. Sheep treated with ‘Cronolone’/progesterone pessaries in the absence of oestradiol showed a mating response of 97%, a conception rate of 64% and 1·7 lambs/conception at the controlled oestrus.

Since its inception in 1894 the American Soil Bureau has investigated many important problems and obtained results which are now common knowledge in this country, but its earlier Bulletins are altogether eclipsed in interest and far-reaching significance by a series recently published. In presenting an account of these it will be most convenient to set out first the purely scientific part of the work, and then the practical applications. This is the logical order and also the order in which the results were actually obtained.

In a previous experiment we investigated the effects of a restricted intake of dietary energy, protein or both on carcass anatomy in pigs (Carden & Goenaga, 1977). Contrary to results of Elsley, McDonald & Fowler (1964) and of Richmond & Berg (1971) we found several changes in muscle distribution, which gave rise to differences in the proportion of the commercially valuable muscles in the carcasses. The treatments had no effect on an important trait, the muscle: bone ratio.

A hand injector was used to inject ammonia into soils in pots in which ryegrass was subsequently grown and under grass in the field; the spacing was varied.

Injecting ammonia or applying ammonium nitrate at one point or three points in the middle of a clay-loam and a sandy-loam soil in pots did not affect the growth of grass or its uptake of N. Grass with ammonium nitrate grew slightly better than with ammonia on the sandy loam and slightly worse on the clay loam.

Best yields of dry matter and most uptake of N were obtained from grass swards having ammonia injected in lines 23 and 30 cm apart and the injection points from onequarter to one-half of the distance between rows. Increasing the distance between lines from 30 to 45 cm diminished total yield and uptake because the strip 15·2 to 22·8 cm from the line of injection grew less than grass nearer to the line of injection.

With grass grown in rows 12·1 cm apart, yields were greatest with the lines of injection perpendicular to the rows of grass and least with the ammonia injected along and into the rows. The yield of dry matter of the row with ammonia injected into it was usually less than of the adjacent row and the percentage N in the grass was usually more, so that the weight of N in the grass sometimes increased and sometimes decreased with distance from the line of injection depending on the relative changes in yield of dry matter and of percentage N.

Phaseolus vulgaris is grown in the U.K. primarily for its edible immature pods (dwarf French beans). The possibility of also using this species as a combinable break crop in south-east England was investigated during 1972–80 when trials were undertaken on the nitrogen fertilizer requirement for commercial seed production.

The practical advantages accruing from the use of lime are now generally recognised, but on account of the complexity of the changes induced it is by no means easy to determine, in the case of a field soil, the exact extent to which one effect or set of effects has contributed to the general improvement of the soil in relation to its crop-producing power.

The seedling emergence from fluid-drilled germinating and natural onion seeds was compared at five sowing dates between 10 February and 18 May on irrigated and unirrigated plots in two experiments. In the second experiment fluid-drilled seeds selected for uniform germination were also included. There were few significant differences between the emergence of seedlings from germinating and natural seeds in the field sowings of Expt 1. However, a reduction in mean emergence time at the earliest sowing led to an increase in bulb weight while a reduction in the spread of emergence at sowing 3 led to a reduced coefficient of variation of bulb diameter at harvest. Under the less variable conditions on the irrigated plots of Expt 2 germinating seeds reduced mean emergence time and increased percentage emergence compared with natural seed at some sowings. Fluid-drilled selected germinated seeds, however, reduced mean emergence time and increased percentage emergence at every sowing and reduced the spread of emergence at all but the first sowing compared with natural seed.

Low soil moisture content made seedling emergence more unpredictable and reduced the benefits gained by sowing germinated seeds. The results presented suggest that techniques to increase the proportion of germinated seeds at the point of sowing and economical methods of applying water during periods of low soil moisture following sowing are needed if the full benefits of fluid drilling are to be realized.

1. After synchronization of oestrus by treatment with progesterone before tupping small groups of ewes were slaughtered at approximately monthly intervals from 5 weeks post-conception to around 3 months post-weaning on two widely differing Scottish hill farms. A few barren ewes were also slaughtered.

2. Ash analysis of the 3rd, 4th and 5th cervical vertebrae of the breeding ewes indicated that there was a striking similarity between the flocks in the mean percentage ash values of these bones and also in the decline in these values which occurred between early gestation and 12 weeks after lambing.

1. Evidence is presented to show that compared with an unmulched soil, a surface mulch reduces the nitrate-N levels significantly following an application of a nitrogen fertilizer during the rains.

2. Natural nitrate-X values in the top-soil were lower under a gravel mulch than a Napier grass mulch. It is concluded that the effect of a Napier grass-mulch cover in lowering natural soil nitrogen-N is offset in part by nitrates formed from the nitrogen it contains.

The question of the composition of sugar beet tops and their utilisation for feeding purposes has been dealt with in a recent publication (l). The purpose of the present communication is to record the results of investigations into the problem of the preservation of sugar beet tops by the method of ensilage. The account falls naturally under four headings:

I. Ensilage of sugar beet tops alone.

II. Ensilage of sugar beet tops mixed with wheat chaff.

III. Ensilage of sugar beet tops mixed with wet sugar beet pulp.

IV. Nutritive value, as determined by digestion trials on sheep, of the silage obtained from the mixture of tops and pulp.

The problems involved in estimating the food intake of the grazing animal are considered and an account is given of studies made on eighteen Clun ewes and six Hampshire × Clun wethers. Results are given from sixty-eight observations on the relationship between food intake and a fraction dissolved in the faeces when a milled sample is left to stand in 0·2N-HCl for 18 hr. Using, in addition, data from grazing ewes subjected to total faeces collection during winter and spring 1959–60 it is concluded that 4 consecutive days of collection give a reasonable estimate of faecal output, and that where similar groups of sheep are grazing on the same pasture at the same time it is unnecessary to convert faeces output data to intake figures in order to compare intake-production relationships between individuals within a group. Where, however, comparisons are to be made between individuals or groups of sheep grazing different pastures at different times then it becomes necessary to allow for differences in food-faeces ratios; for this purpose the dissolved fraction discussed here is likely to prove a useful faecal indicator eliminating many disadvantages of earlier methods and some of the seasonal bias inherent in other indicators at present in use.

The formation of Iron Pan or Ortstein is of fairly frequent occurrence both in Britain and on the Continent of Europe. It is of some economic importance, for where it occurs considerable expense has to be incurred before it is possible to grow a crop of any kind on the soil. The Pan consists of a hard layer of material which has to be broken through for successful cultivation, as it is cemented together in such a manner as to prevent any penetration of plant roots and to limit the circulation of air and water.