The influence of sex and gonadectomy on liveweight growth and its components was examined in a comparative slaughter experiment using Southdown – Romney cross lambs run under New Zealand pastoral feeding conditions.

Twenty ram lambs were castrated and 20 ewe lambs spayed at docking, at approximately 4 weeks of age. Ten ram and 10 ewe lambs were killed at this age and 5 lambs from each of the four ‘sexes’ (entire and gonadectomized, male and female) were killed 4, 8,12 and 24 weeks after docking.

Live-weight gain was higher for males than females and higher for entire than gonadectomized lambs, with some evidence of a greater depression in growth associated with castration than spaying. Effects on carcass weight followed those on live weight; weights for entire rams, wethers, entire and spayed ewes were 16.92, 14.72, 14.02 and 12.46 kg. respectively at approximately 7 months of age.

The water content and turnover of six pairs of identical twin cattle were measured in the Kenya highlands. Three pairs were stall fed, and one twin of each pair received water daily. Their water turnover averaged 14.21./24 hr. while the others watered each 4 days had an average turnover of 12.41./24 hr. These stall-fed animals used 74-132 ml./kg.0.82/ 24 hr., about one-third the water turned over by grazing cattle (261-364 ml./kg.0.82/24 hr.). There was little relationship between estimates of water intake measured from the trough and that derived from tritium dilution.

Members of each grazing pair differed in weight by an average of 4.2% and their total body water by 5.9%, whereas the water turnover differed by only 2.2% amongst the twin pairs.

1. An account is given of the occurrence of copper deficiency in crops grown on the Fenland peats and glacial sands of East Anglia. Copper deficiency in the crops appears to be due to actual deficiency of available copper in the peat and sandy soils. The level of copper extracted from soils by an acid solution (pH 4.0) of the ammonium salt of E.D.T.A. provides a useful indication of soils deficient in copper, though the occurrence of the deficiency and its severity in crops is influenced by other soil factors, level of water-table in peats, species of crop and weather during the growing season.

2. Of the crops grown on the peat and sandy soils of East Anglia the most susceptible to copper deficiency are cereals. Visual symptoms of deficiency are described as these provide an important aid in diagnosis.

The influence of sex and gonadectomy on carcass grades, measurements and chemical composition is reported from a comparative slaughter experiment involving 100 Romney x Southdown cross lambs.

Grading results, although based on small numbers of carcasses, showed a tendency to down grade entire ram lamb carcasses.

Linear carcass measurements indicated some differences in conformation between the four ‘sexes’, although these were somewhat inconsistent over the two slaughter ages at which measurements were recorded. Relatively larger eye muscle areas were evident for gonadectomized than for entire lambs and for males than for females. Fat cover over the eye muscle was lower for entire rams than for the other ‘sexes’.

The great majority of the fibre-type arrays from the backs of eighty Merino lambs were Plain (including Coarse Plain); Plateau and other arrays also occurred. In most samples no medulla could be seen in the pre-natal parts of halo-hairs examined in benzene, but the presence of medullary substance was demonstrated. All HH were shed and apparently replaced by fine fibres. The shape of the tip curls of early CT fibres in some samples altered with age, apparently by 'setting' in a line of yolk. HH grades ranged from I to VII and there were probable strain differences in grade and medullation.

A total of 599 primary and 2595 secondary follicles and their fibres were identified by dissection. Primary follicles contained HH, SS, Sk, or early CT fibres, secondary follicles only CT or Hi. Sickle fibres commonly occupied most of the PL follicles except where the array was Plateau.

Evidence is provided that T. ambiguum, in common with other legumes, responds to inoculation with an effective strain of Rhizobium both in the field and in the glasshouse. There were consistent differences between the responses of 2x, 4x; and 6x: chromosome races to inoculation. Grass plants grown alongside effectively nodulated T. ambiguum plants gave significantly higher yields than those grown with ineffectively nodulated plants. The higher percentage germination associated with inoculation may be due to an effect of the skim milk used as inoculum carrier.

We wish to thank Professor P. T. Thomas and Mr W. Ellis Davies of the Welsh Plant Breeding Station, for their interest and advice, and Professor A. H. Bunting, of Reading University, for reading and correcting the manuscript.

1. The cutaneous evaporation rates of three animals of different genotype have been determined under artificial heating in a climate laboratory and during exposure to field conditions. Cutaneous evaporation rates were measured from the backthoracic region using a ventilated capsule technique.

2. In both climate-laboratory studies and field observations cutaneous evaporation showed little relationship with either rectal temperature, respiratory rate or skin temperature.

3. Basal cutaneous evaporation rates in the unheated chamber at 10 a.m. were found to be 40% lower in animals which were housed overnight than in those which entered the chamber following exposure to the early morning sunlight.

A study of the horizontal and vertical distribution of herbage in grass-dominant swards was made to assess the relative importance of different sources of wastage during grazing. A sward grazed by cattle under two contrasting managements was divided, for the purpose of herbage sampling, into two categories: ‘grazed’ herbage, on ground with no obvious dung contamination, and ‘dung patches’, which were of ungrazed or lightly grazed herbage resulting from the effects of faeces dropped at previous grazings. In each category, samples were cut at two successive heights to provide an estimate of the quantity of herbage in the upper region of the sward (over 2½ in. from ground level) and in the lower region (½-2½ in. from ground level).

After grazing, some 35% of the original crop remained in ‘grazed’ areas, and some 20% in ‘dung patches’. In terms of vertical distribution, most of the residue (40% of the original crop) was in the lower region, from ½ to 2½ in. above ground level.

Total production as live-weight gain was not significantly different, but the yield of conserved herbage was greater in treatment R (five rotations) than in treatment RR (nineteen rotations). Frequent grazing reduced herbage production, and this effect was not offset by any less intense defoliation of the frequently grazed sward. The average quantity of herbage residue was no higher in treatment RR than in treatment R, although the time of occupation per plot by the cattle in RR was only a quarter of that of the cattle in treatment R.

The half-carcasses from twelve Dorset Horn x Border Leicester-Merino lambs (3-5 months old) were used to investigate the relationships between the weight of the carcass and its cuts and their chemical composition. The specific gravity of the whole carcass and of the cuts was also measured.

Half-carcass weight and chemical composition were highly correlated. Weight could be used to predict the chemical composition with a reasonable degree of accuracy. The loin, the leg, the leg plus loin and the residual were shown to be highly correlated with the chemical composition of the halfcarcass. The loin and leg plus loin are the most convenient to use.

Since sugar beet was first grown on farms it has been difficult to establish single seedlings at the required spacing because each seed unit was liable to produce a cluster of seedlings. Plant breeders have introduced varieties with monogerm seed and these were used between 1960 and 1962 to see if they led to any savings in labour with hand and machine thinning and to determine the yields of beet after these treatments. The trials described show that, after machine thinning, predetermined final plant populations with 90% of single seedlings were obtained and, when a herbicide was effective in weed control, the labour requirement was about 5% of that required to hand single a crop from multigerm seed. When singled by hand the monogerm varieties required 90 % of the labour needed to single a multigerm crop but the mean yield per acre of the monogerm varieties used was at least six tons per acre less than that from a commercial variety with multigerm seed.

The inoculation of legumes is often carried out using skim-milk as the carrier for the nodule bacteria. Increased germination due to inoculation has often been reported but in this investigation the effects of the skim-milk and the bacteria have been separated. The results indicate that the early establishment of T. ambiguum was stimulated by the skim milk rather than the nodule bacteria. The mechanism of this effect is thought to be due to extra N present in the milk and possibly to an enhanced nitrogen-cycle in the inoculated soil and evidence is produced of increases in certain freeliving nitrogen fixing and nitrifying microorganisms.

The effect of stocking-rate was measured on growth of indigenous oxen grazing Hyparrhenia veld and dambo. Stocking-rate had a relatively small effect on weight gain per ox in the rainy season when veld was relatively nutritious, but had a significant linear effect and a lesser quadratic effect on weight loss per ox in the dry season. Oxen stocked leniently on veld in the dry season lost less weight than heavily stocked oxen. Oxen fed a protein supplement, maintained or gained weight when grazing veld in the dry season even at high stocking-rates.

In long-term trials, compensatory growth so affected cattle weight gains that heavily stocked oxen which had large weight losses in the dry season compared with leniently stocked oxen, had greater weight gains in the following rainy season. Stocking-rate had a highly significant, linear effect on cumulative weight gain per ox, which was more evident on dambo grazing than on Hyparrhenia veld.

Large-scale field trials in sugar beet were undertaken between 1961 and 1963 to examine the effects of chemical or mechanical weed control followed by machine thinning in terms of labour economy and yield of the crop. The seedling populations were left untrimmed by hand and, where the weed-control measures were completely effective or nearly so, the crops were left unweeded. Yield samples were taken both by hand and by machine so that the potential yield as well as the likely commercial yield might be determined. The chemical and mechanical methods that were studied saved about 75% of the normal labour demand and gave root yields 91.5% of those following hand work.

At Saxmundham Experimental Station in East Suffolk a four-course rotation experiment testing fertilizer treatments has continued with only minor modifications since the 1899/1900 crop year, the crops being wheat, roots (mainly mangolds), barley and either beans, peas or clover. Factorial combinations of nitrogen (N), phosphorus (P) and potassium (K), with two additional treatments testing farm-yard manure and bonemeal, are applied annually to the same plots regardless of crop.

All crops, particularly mangolds and sugar beet, yielded badly without P. N was as important as P for cereals, but had little effect on mangolds and sugar beet unless P was also applied; its effects on the legume yields were slight. On this heavy soil K had little effect on the yield of any crops except the legumes.

1. Three varieties of wheat with white grain and eleven with red grain were examined for a-amylase content of the grain and for resistance to germination in the ear when harvest was delayed.

2. There were large differences between varieties in a-amylase activity. These were due partly to differences in susceptibility to germination in the ear, which always resulted in increased a-amylase activity. There were also large differences between varieties in the a-amylase content of grain which had no visible indication of germination. These differences were not related to susceptibility to germination and were confirmed by a glass-house experiment in which the ears were always dry from emergence to harvest.

Six steers kept in an environment of 15°C. were deprived of water for four consecutive days. This treatment, by depressing appetite, caused a reduction in voluntary hay intake to one-quarter of its normal level and a decrease in body weight by 10%.

In spite of this reduction in feed intake, which must have been accompanied by a fall in metabolic heat production, the animals were less able to tolerate heat than when they were normally watered: during 4 hr. exposures to temperatures of 40.0°C. dry bulb and 32.5°C. wet bulb the waterdepleted animals showed higher values of rectal and skin temperature. This was associated with a slower initial rise and lower final values of respiratory rate (130 versus 155 respirations/min.).

The rotation II experiment at Saxmundham, which ran from 1899-1952, was designed to show how limited quantities of FYM, N and P could best be allocated to the crops of a four-course rotation; there were also tests of additional quantities of N and P. Both FYM and P fertilizer gave large increases in the yield of all crops, but the profitability of the rotation as a whole proved to be little affected by which crops received FYM or P fertilizer. The rates of N tested were too small to provide any information relevant to current farm practices. The optimal dressing of P fertilizer at 1965 prices was 0.5-0.6 cwt. P2O6 per acre.

1. Three creep feeds containing 14, 18 and 22% crude protein of similar protein quality (as measured by total lysine and total methionine plus cystino content) but with similar levels of other nutrients were given ad libitum to 210 pigs, the progeny of thirty large White sows from 21 to 56 days old.

2. At 21 days old, each litter was reduced to seven piglets by killing one, two or three pigs at random. The whole pig was analysed for protein, ether extract, ash and dry matter.

3. At 56 days, 3 further pigs were killed in each litter and analysed in a similar manner.

1. The yield and composition of milk from twenty Border Leicester x Cheviot ewes offered dried grass cubes, dried grass cubes and hay, hay or grazing was determined over a lactation period lasting 10 weeks. Milk yield was estimated by weighing the lambs before and after each suckling on one day each week. Samples of milk for analysis were obtained at fortnightly intervals by hand milking the left side of each udder before the mid-day suckling by the lambs.

2. Ewes receiving dried grass cubes and suckling twins and those receiving dried grass cubes and hay reached mean peak milk yields of 3470 and 2680 g./day, respectively, at 2-3 weeks after parturition, whilst the yields of the remaining ewes declined continuously from the beginning of lactation. The mean milk yield over the lactation of ewes receiving dried grass cubes and suckling twins was 2785 g./day, of those receiving dried grass cubes and suckling singles 1821 g./day, of those receiving dried grass cubes and hay 2119 g./day and of those receiving hay 1177 g./day. The yield of milk energy was highest for all ewes during the first week after parturition.