1. Milk yields of thirteen Blackface ewes with single lambs were estimated over a period of 6 weeks at the hill farm of Glensaugh (Kincardineshire) and a further twenty-nine at Stanhope (Peeblesshire).

2. The estimated average total milk yield over 6 weeks was 159 lb. at Glensaugh and 96 lb. at Stanhope. Recorded yields ranged from 86 to 220 lb. at Glensaugh and from 65 to 131 lb. at Stanhope.

3. The average daily live-weight increase of lambs was 0·72 lb. at Glensaugh and 0·43 lb. at Stanhope. Daily live-weight increases ranged from 0·23 to 0·91 lb.

4. At Glensaugh the average lactation curve reached a maximum 24 days after lambing. At Stanhope, the average lactation curve showed a peak 10 days after lambing and another peak 32 days after lambing. The lack of uniformity in this curve was attributed to changing conditions of nutrition.

5. Linear regression was found between ewe milk yield and daily live-weight increase in lambs, and the correlation between ewe milk yield and ewe live weight was highly significant, though the regression coefficient is fairly small.

6. Four samples of ewe's milk were analysed.

7. The correlation between ewe milk yield and daily live weight increase in lambs persisted when figures representing other breeds of ewes (with single lambs) were included in the calculations.

Thirty-five buffalo heifers were tested daily with fertile males to ascertain the age and live weight at first possible oestrus and conception. Patterns of sexual behaviour were recorded while rectal palpation was carried out to define the conditions of the ovaries and to diagnose pregnancies. The mammary gland development, as well as the intensity of lactation, were noted post partum.

1. Pubertal matings were allowed with less certainty than adult matings. The signs of oestrus were intensified by the recurrence of heat and association with the male. Homosexuality was only observed in the first and second oestrus.

2. The average age of first oestrus, first conception and first calving were 406, 647 and 963 days respectively. The body weight at first oestrus and first conception were 198 and 319 kg. respectively.

3. The number of services/conception ranged from 1 to 7 with an average of 4·25. The number of silent heats/female ranged from 1 to 4 with an average of 1·65. The period elapsing from first oestrus to first conception ranged from 52 to 438 days. Before conception, there was a period of anoestrus which ranged from 115 to 314 days, this was probably due to weak oestrus symptoms.

4. The live weights at 28, 84, 140, 196, 252 and 308 days were correlated with the age and live weight at first oestrus as well as the live weight at first conception.

5. All the buffalo-cows except two which showed oestrus conceived. Fourteen animals calved normally while fourteen aborted after 131–318 days. The gestation period ranged from 312 to 321 days with an average of 316 days. The birth weight of young ranged from 33 to 40 kg. Seven animals were not lactating while seven gave 1–2 kg. of milk.

6. Puberty phenomenon is a gradual phenomenon and is attained in steps: sexual desire, ovulation, oestrus, conception, pregnancy then lactation.

Fertilized ova have been transferred from Border Leicester to Welsh Mountain ewes, and vice versa. The oestrous cycles of the ewes were synchronized by progesterone treatment, and donor ewes were super-ovulated with PMS. 68–90 hr. after the onset of oestrus in the donors, thirty-seven ova, representing 58% of the ovulations, were recovered in vivo from thirteen ewes. Nineteen ova were transferred to eighteen recipient ewes and a total of eight pure-bred lambs were born to ewes of the opposite breed.

Transfers resulted in pregnancy when oestrus in the recipients commenced from 16 hr. before to 20 hr. after that in the donors; two of the ova which developed to term were 4-cell, five were 8-cell and one was a 16-cell ovum at the time of transfer. Four out of seven and four out of eleven transfers, using blood serum and Ringer's solution respectively, resulted in the birth of lambs. Prior to transfer to the recipients seven of the ova which developed to term were exposed for 30–45 min. at room temperature, whilst one developed after exposure for 70 min.

1. Under normal English storage conditions, the heat production of mature potatoes drops rapidly from a value of probably about 150 b.th.u./ton/hr. immediately after harvest to about 30–50 b.th.u./ton/hr. Sprouting is accompanied by an increase in the rate of heat production. The initial heat production of immature potatoes may be of the order of 250 b.th.u./ton/hr.

2. As a result of the production of heat, the temperatures in stacks of potatoes will tend to rise to levels above that of the outside air which are just sufficient to cause the convection and conduction necessary to remove the metabolic heat as fast as it is produced.

3. The difference in temperature between the potatoes and the ambient air is a function of the heat production of the potatoes and of the height of the stack, and is practically independent of its other dimensions if these exceed twice the height. Under average conditions during the middle of the storage season, and for heights of storage of from about 6 to 12 ft. it may be taken as a rough practical guide that the average and maximum temperatures of the potatoes will tend to exceed the average temperature of the store air by about 2/3 and 1° F. respectively for every foot of height.

4. Overheating is possible at both the beginning and end of the storage season, when heat production is high and the outside temperatures also possibly high. In general it is safe to store unventilated potatoes to a height of about 6 ft. if they are mature, though if they are harvested with a great deal of earth late storage should not be attempted. If there is no intention of storing late, and the potatoes are fairly clean, storage to aheight of 12 ft. may be permissible. Immature potatoes should not be stored to a height of more than 3 ft.

Ram semen was stored at 4° C. in a standard citrate-egg-yolk diluent, which served as a control, and in various diluents in which: (a) the citrate buffer was replaced by various concentrations of glycine in water (2, 3, 4 and 6%); (b) the ratio of semen to diluent was altered from 1:20 to 1:40; (c) the glycine buffer was augmented by the addition of fructose; and (d) the concentration of egg yolk in the diluent was reduced from 50% to 33·3 and 25%.

Replacing citrate buffer by 4% glycine considerably improved survival as against other concentrations of glycine and the citrate buffer control. Better survival in 4% glycine-egg-yolk buffer was obtained with a semen dilution ratio of 1:20 than with a ratio of 1: 40. The addition of fructose to the glycine buffer did not improve survival. The 50% concentration of egg yolk in 4% glycine buffer-eggyolk diluent was reduced to 33·3% without affecting either motility or survival, and to 25% with no effect on survival but with slight reduction in motility.

Experiments were made on twelve rams to determine the effects of hormonal treatment on rams with poor libido. Testosterone and PMS were used and sexual behaviour, and semen characteristics such as volume, motility, impedance-change frequency and dead percentage were studied. The libido was higher in testosterone-treated rams than in the PMS-treated, or in the control rams. Volume of ejaculate was also higher in the former group. There was not much difference in the motility ratings. Impedance change frequency was slightly lower and dead percentage higher in the semen produced by testosterone-treated rams than in other groups.

1. Certain carcass measurements (length, shoulder and mid-back fats, belly thickness and dressing percentage) made on a total of 402 bacon pigs from four antibiotic feeding trials have been analysed.

2. The length of the carcasses showed more variation between pens treated with various doses of penicillin than between control pens or pens treated with aureomycin. This greater variation in length was related to the greater variation in growth rate between the penicillin treatments. No differences in the mean lengths of control, penicillin and aureomycin treatments were found.

3. Back fat measurements and belly thickness showed no differences between aureomycin, penicillin and control treatments in overall tests.

4. Aureomycin consistently gave higher dressing percentages than penicillin. Animal protein also gave higher dressing percentages than vegetable protein, but no effect of vitamin B12 on this quantity was found.

An inquiry has been made to determine whether shearling rams sire more good-quality offspring than would be expected from the proportion of them used in Swaledale flocks in northern England, 1951–3.

Quality was assessed at two levels, both concerning shearling rams: those passed for registration in the Flock Book, and those making £50 or more at Kirkby Stephen ram sale.

The expected percentage of lambs, and hence good-quality offspring, by shearling rams was estimated from the practice on a sample group of farms, using the formula

where E is the estimated percentage of lambs by shearlings, x the proportion of shearlings to all rams in use, and y the fractional value in numbers of ewes served where aged rams are regarded as having unit value.

The estimated percentage of lambs by shearlings is 28·7, with s.e. = 2·444.

The actual percentage of registered shearlings sired by shearlings in 1951–3 was 35·7 with s.e. = 0·764, and the actual percentage of shearlings sold for £50 or more in the same years was 32·8 with s.e. = 3·313.

That shearlings sire a slightly, but significantly, higher number of registered shearlings than would be expected is probably due to the transmission of earlymaturing qualities, since shearlings of high quality are consistently used in early-maturing, and therefore shearling-producing, flocks. Those likely to sire ‘£50’ shearlings often remain in early-maturing flocks throughout life and, by continuing to sire this high-quality progeny, depress the percentage of such shearlings sired by shearlings to a figure not significantly higher than the ‘expected’ figure.

1. Pollen mother cells with irregularities of meiosis were rare in the parent species and varieties, being usually less than 0·5% and the highest found being only 1·57% in the variety Grey Winter.

2. F1A. fatua C.S. 473 (from Afghanistan) × Grey Winter had 33·5% of pollen mother cells with irregularities. On the other hand, the F1 hybrids of A. fatua (C.S. 46 (from Asia Minor) × both spring and winter varieties of A. sativa showed between 2·45 and 12·81% of irregular cells and were thus more regular than F1 spring variety of A. sativa × Grey Winter.

3. F1A. sterilis × spring and winter varieties of A. sativa showed between 5·56 and 6·67% of cells with irregularities of meiosis.

4. F1A. fatua C.S.46 × A. sterilis and F1A. nuda × A. sterilis had 5·65 and 7·60% of irregular cells respectively, but F1A. nuda × A.fatua C.S. 46 had 46·05%.

5. All F1 hybrids with A. byzantina as one parent had high frequencies of pollen mother cells (from 59·12 to 88·45%).

6. The commonest irregularity of meiosis was the occurrence of univalents. Multivalents were found at a high frequency only in the A. byzantina hybrids. Bridges and fragments were uncommon, occurring in not more than 2% of cells.

7. The limitations of the cytological results in assessing the relationships between the different hexaploid species of oats are discussed. It would, however, appear that there is a close relationship between A. sativa (both spring and winter varieties), A.fatua (C.S. 46) and A. sterilis, but that A. byzantina is not closely related to that group.

8. The importance of the results to the plant breeder is briefly indicated.

A brief account is given of the accepted view that riboflavin supplements in the diet of breeding stock lead to improved hatchability and that clubbed down is specific for a deficiency of this vitamin. Attention, however, is drawn to the apparent failure of various workers to achieve a hatching rate with a riboflavin supplemented diet substantially in excess of 80% of fertile eggs which appears to be the national average figure. An experiment is described in which range managed breeding stock received diets supplemented with riboflavin at varying levels, the lowest of which, in the light of available evidence, would be sufficient for good hatchability having regard to the riboflavin obtained by the stock from grass and their own droppings. The hatching rate of fertile eggs was maintained at about 80% with all rations and little change took place consequent on changing over from high to low or vice versa. Only a very small improvement was observed with a very high level of riboflavin. It is therefore concluded that either a figure around 80% hatchability represents the maximum influence of riboflavin on hatching rates or that there are generally other factor(s) present (or absent) in the embryo that prevent a higher rate being achieved. The evidence submitted suggests that this factor may be B12 or more probably, one of the unidentified factors in the A.P.F. complex, and that for hatching rates materially above 80% the A.P.F. complex must be increased above the levels presently supplied to range managed breeding stock, or the high hatching rates induced by high levels of riboflavin may greatly increase the birds' requirements for this factor(s) to a level well above that normally necessary.

Attention is also drawn to the incidence of clubbed down among dead-in-shell with varying levels of dietary riboflavin. It is concluded that the presence of this embryonic abnormality is rapidly and almost completely influenced by changes in the level of dietary riboflavin and that these changes take place much more rapidly than changes in hatchability, once a moderately high hatching rate has already been reached. It is also contended that high riboflavin levels will almost eliminate the incidence of clubbed down, although an already moderately high hatching rate will remain unaffected. For this reason it is argued that the presence of clubbed down in some dead-in-shell is no conclusive evidence that an improvement in hatchability will follow supplementation of the diet with riboflavin unless the hatching rate is below average.

1. In general the juvenile growth of interspecific Triticum and intergeneric Tritioum-Aegilops amphidiploids, was normal and did not deviate from the parental behaviour. However, in the case of the interspecific hexaploids derived from T. monococcum and T. aegilopoides there was an early check in growth, and all the amphidiploids derived from A. caudata developed more or less severe chlorosis.

2. Most amphidiploids were intermediate between their parents in mature plant characters. However, in the hexaploid Triticum interspecific amphidiploids there was a transgressive increase in plant height, and whilst the derivatives of Triticum x Aegilops crosses fell within the range of their parents, they were closer to one or other parent depending upon the Aegilops species involved.

3. The ear morphology of the Triticum interspecific amphidiploid was generally a composite of that of the parents, the influence of each parent being detectable. In the Triticum-Aegilops amphidiploids, however, ear morphology was so strongly influenced by the Aegilops species, that there was frequently no obvious difference between the ears of amphidiploids with a common Aegilops parent but different wheat parents.

4. The fertility of the amphidiploids was low and there was no significant correlation between the fertility of amphidiploids and parents. There was a significant correlation between both the grain weight, and number of spikelets per ear, in parents and amphidiploids, but whilst the mean grain weight was about that of the parent with the heavier grain, the mean of spikelets per ear was about that of the parent with the fewer spikelets.

1. Observations have been made of the seedling reactions of species of Triticum and Aegilops and of amphidiploids between them to races of Puccinia glumarum, P. triticina, P. graminis and Erysiphe graminis. These observations have been compared with field observations on mature plants. The work on P. graminis and much of that on P. triticina was carried out by Dr R. C. McGinnis of the Dominion Rust Research Laboratories, Winnipeg, Canada.

2. Seedling and mature plant resistance to P. glumarum has been found in Triticum monococcum, Aegilops caudata and A. ovata. Resistance was not shown by amphidiploids of T. monococcum and A. caudata with susceptible species of Triticum, but was shown by some amphidiploids involving A. ovata; T. timopheevi and A. speltoides were susceptible to certain races as seedlings but resistant as mature plants in the field.

3. Seedling resistance to all the races of P. triticina used in these investigations was shown by A. caudata and resistance to certain races by certain other species. Amphidiploids involving A. caudata were resistant to all races, but other amphidiploids were resistant to some races and susceptible to others.

4. Seedling and mature plant resistance to P. graminis was shown by A. caudata. A. ovata and A. speltoides were resistant as mature plants, and only slightly infected as seedlings. None of the amphidiploids tested was completely resistant at the seedling stage; certain amphidiploids involving these three species were, however, only slightly infected as mature plants, and may be useful as sources of resistance to race 15B.

5. Resistance to E. graminis was shown by T. carthlicum, T. dicoccum, T. timopheevi and by numerous species of Aegilops. Amphidiploids of T. carthlicum, T. dicoccum, T. timopheevi and A. caudata with diploid wheat species were resistant to E. graminis, but those with susceptible tetraploid wheats were susceptible. Other intergeneric amphidiploids (with two exceptions) were resistant.

1. The chemical nature of the nitrogen in humic acid preparations isolated from 0·5M-sodium hydroxide and 0·1M-sodium pyrophosphate (pH 7·0) extracts of nine different soils has been studied by determining the amounts of acid-soluble-N, ammonia-N, amino-sugar-N and α-amino-N liberated by acid hydrolysis of the preparations and by paper chromatographic analysis of their acid hydrolysates.

2. Humic acid preparations isolated from alkali and pyrophosphate extracts of the same soil differ markedly in total nitrogen content and in nitrogen distribution after acid hydrolysis. The alkali-extracted preparations have a higher nitrogen content and a higher proportion of acid-soluble-N and α-amino-N.

3. A considerable fraction (20–60%) of the nitrogen in the preparations examined was not dissolved by acid hydrolysis. The major fraction of the nitrogen dissolved was in the form of amino-acids.

4. At least 31–48% of the nitrogen in the alkaliextracted preparations and 20–35% of the nitrogen in the pyrophosphate-extracted preparations was in the form of protein. From 3 to 10% of the nitrogen in the preparations was in the form of amino-sugars.

5. The results obtained by paper chromatographic analysis of acid hydrolysates of the preparations indicated that the protein materials in humic acids isolated from different soils by alkali or pyrophosphate are similar in their amino-acid composition. The following nineteen amino-acids were detected in every hydrolysate examined: phenylalanine, leucine, isoleucine, valine, alanine, glycine, threonine, serine, aspartic acid, glutamic acid, lysine, arginine, histidine, proline, hydroxyproline, α-amino-n-butyric acid, β-alanine, γ-aminobutyric acid and tyrosine. Two unidentified ninhydrin-reacting substances, oxidation products of cystine and methionine, and amino-sugars were also detected in every hydrolysate examined. A third unidentified ninhydrin-reacting substance and a substance provisionally identified as α,ε-diaminopimelic acid were found in some of the hydrolysates.

An account is given of experimental work carried out at Jealott's Hill on bloat.

Bloat was produced in dairy cows and sheep by dosing with lucerne juice. Sheep proved convenient test animals and were used in most of the tests described.

Parenteral and intravenous administration of the flavone quercetin, which inhibits the activity of smooth muscle, did not cause bloat even in the presence of cyanide. It is unlikely that flavones are concerned in bloat.

Fractionation of bloat-provoking lucerne juice showed that activity was retained after (a) precipitation of chloroplastic material, and (b) passage of clear juice through an anion or cation exchange resin. This suggests that the bloat-provoking factor is non-ionic and not adsorbed on resins—properties shown by saponinis.

Dosing sheep with lucerne saponins, four other saponins, egg albumin and a synthetic foaming compound failed to produce bloat.

Two household detergents and a number of surface-active agents did not relieve bloat, but foam-breaking compounds were very effective.

A synthetic inorganic saliva and cow's saliva did not prevent bloat in sheep and from the single test made with cow's saliva it is not possible to say if it increased the severity of bloat.

It is concluded that the formation of a stable foam is a major factor in lucerne bloat and that food constituents, other than saponins, and the physical condition of the rumen ingesta probably influence the stability of the foam.