bluuebunny/crossref_metadata_2025 huggingface dataset:
Heterosis and combining ability in hybrids ofAvena sativaL. andA. byzantinaC. Koch.
Authors: Jenkins G.
Published: March 2009

Three varieties ofAvena byzantinaC. Koch., Sierra, Avon and Anita, originating respectively in California, Australia and South Africa, together with the Dutch variety Condor (A. sativaL.) were used as ‘subject’ varieties in crosses with a range of nine tester varieties of mainly north-west European origin. The results of a yield trial of spacedF1transplants and a drilledF2trial are presented.

In theF1trial there was marked heterosis for grain yield, the thirty-six crosses yielding, on average, 109 % of the higher yielding parent, with individual cross values ranging from 68 to 139%. Heterosis was more marked insativa × byzantinacrosses than insativa × sativacrosses and the variety Sierra showed particularly high general combining ability. In theF2trial, heterosis was considerably reduced and the thirty-six crosses yielded, on average, only 96% of the higher yielding parent. In someF1crosses, heterosis for grain yield was accompanied by transgression of the higher yielding parent in number of panicles per unit area. The number of grains per panicle was positively correlated with grain yield in theF2trial but no heterosis was observed for this component. Grain size was negatively correlated with yield in theF2trial and heterosis for this component was observed in a few crosses in which yield heterosis occurred.

Straw height was positively correlated with grain yield in theF1trial but negatively correlated in theF2trial. Crosses showing heterosis for yield exceeded the mid-parent but not the taller parent in straw height. The ratio of grain yield to straw yield was higher for the progenies of thebyzantinavarieties Sierra and Avon than for the progenies of thesativasubject Condor. Grain yield was positively correlated with number of days to 50% panicle emergence in both trials.

It is concluded that theA. byzantinavarieties Sierra and Avon could, with advantage, be used for hybridization with adapted genotypes ofA. sativa, thereby enlarging the gene pool available to oat breeders in north-west Europe.
Effect of low skin surface temperature on wool growth
Authors: Downes A. M. , Hutchinson J. C. D.
Published: March 2009

The length of wool grown per day, on closely clipped patches of the skin of two sheep exposed to an ambient temperature of 2 °C for 4 days, was reduced to 30% of normal. For individual fibres, this decrease was directly proportional to their normal growth. Fibre diameter was not affected. Growth in a warm 4-day period succeeding the cold period returned to normal and remained normal thereafter.
The digestibility of oat hay
Authors: Walker H. F.
Published: March 2009

1. Digestibility trials, using sheep, were carried out on five batches of oat hay grown during 2 years; nitrogen balance experiments were made simultaneously.

2. The oat hay was not readily consumed by the sheep; this necessitated calculating the digestibility data on an ‘as consumed’ and on an ‘as offered’ basis; it also prevented a majority of the sheep from obtaining their maintenance requirements of energy or from maintaining nitrogen equilibrium.

3. Statistical analysis of the data revealed a downward drift in digestibility in the succeeding periods of the 1955 trial.

4. While stage of maturity had little consistent effect on digestibility or on the amounts of digestible nutrients present, the percentage digestible crude protein did increase with advance in maturity.

5. The amounts of digestible nutrients present in oat hay indicated that it had a nutritive value between those of oat straw and medium-quality meadow hay.

6. The data suggest that the maximum yield of digestible nutrients is obtained when the oat hay is cut at the ‘late cheesy’ stage of maturity.
The isolation of ‘pure lines’ fromF1hybrids of tomato, and the problem of heterosis in inbreeding crop species
Authors: Williams Watkin
Published: March 2009

1. The problem of inbreeding and the fixation of apparent heterosis in the cultivated tomato and in inbreeding crop species generally is discussed. The case is argued that ‘heterosis’ as normally understood in out-breeders is not likely to exist as a general phenomenon in inbreeding species.

2. Selections were made among segregating progenies of two successful, commercialF1hybrids, and the performance of the selected lines, up to theF4generation, shows that the superiority of the hybrids over their parents can be fixed in purebreeding lines.

3. Owing to selection effects in inbreeding species of crops the best parents will differ in respect of fewer quantitative loci than is to be expected from general experiments on quantitative inheritance. In the present material, desirable recombinants were isolated at a frequency of 1 in every 1000–1500F2individuals.

4. The utility ofF1hybrids in the tomato thus depends on the economy of effort involved in their development as compared with the isolation of pure lines. It is concluded that the production of hybrids is to be favoured only when reliable methods of prediction of their performance are available, and then as an interim measure while pure-line forms become available.
Grazing behaviour of calves reared at pasture
Authors: Chambers D. T.
Published: March 2009

1. Observations were made on the behaviour of young spring- and autumn-bom calves reared at pasture.

2. Bucket-fed calves rapidly learnt to graze, whereas single-suckled animals running with their dams made no serious attempt to graze until they were 6 weeks old.

3. The time spent in grazing was modified by the presence of hay and probably by that of concentrates, and it was influenced also by the quality and quantity of herbage on offer.
The effect of plant spacing on grain yield of tall and short sorghum in Nigeria
Authors: Goldsworthy P. R. , Tayler R. S.
Published: March 2009

The grain yield, head structure and components of yield of a Nigerian long-season sorghum (Farafara) and an American hybrid short-season type (NK 300) were compared at three populations. The effect of thinning at initiation and at heading was also examined.

At each population, the grain yield per plant of NK 300 was larger than that of Farafara, mainly due to differences in the number of grains per head. This factor was also the main one responsible for a decline in yield per plant with increase in population. At all populations, Farafara plants showed an appreciable increase in stem weight after heading.

The results from the thinning treatments suggest that the main difference between the two varieties is in the number of spikelets present at head emergence: the number and/or potential size of developing grains in Farafara appeared to be largely determined by the time of initiation and was probably too small to accept all the currently produced assimilate.
The effect of wilting berseem and lucerne herbage on voluntary dry-matter intake by buffalo heifers
Authors: Yoelao K. , Jackson M. G. , Saran Ishwar
Published: March 2009

Two changeover experiments, each on eight buffalo heifers, were conducted in two different years to determine the effect of wilting lucerne herbage (Exps. 1 and 2) and berseem herbage (Exp. 2 only) on voluntary dry-matter intake. The dry-matter content of the herbages increased by field wilting from 27 to 50 and from 26 to 44% for lucerne in Exps. 1 and 2 respectively, and from 21 to 31% for berseem. The drymatter intake, nutrient digestibility coefficients, nutritive value index and retention time of undigested residues were determined for each fresh and wilted herbage.

Wilting increased the dry-matter intake of lucerne from 2·3 to 2·8 and from 2·1 to 3·5 kg per 100 kg body weight in Exps. 1 and 2 respectively. Berseem dry-matter intake was increased from 2·2 to 3·1 kg per 100 kg body weight. Digestibility coefficients of all nutrients of both herbages increased by 6–20%. Retention times were unaffected by wilting. The nutritive value indices for lucerne and berseem in Exp. 2 increased by 160 and 60% respectively. In Exp. 2, the average loss of herbage dry matter due to wilting was 3·8%. The higher consumption of the wilted herbages is ascribed to their lower water content. The practical implications of these results are discussed.
Effects of experimentally produced local subdermal temperature changes on skin temperature and wool growth in the sheep
Authors: Lyne A. G. , Jolly M. , Hollis D. E.
Published: March 2009

A heat-exchange chamber made of perspex was inserted beneath the skin of a Merino sheep. By passing water at predetermined temperatures through the chamber, the normal subdermal temperature of 37°C was raised approximately 4°C for 4 days, then lowered approximately 5°C for 4 days.

In response to heating, the animal's temperature regulating mechanism was able to maintain a fairly constant subdermal temperature. However, it was unable to maintain as constant a subdermal temperature in response to cooling. There was, during the cooling period, an obvious nervous response to environmental disturbances manifested by sudden transient decreases in subdermal temperature over the chamber.

During the cooling period there was a decrease of 12% in mean length growth rate of wool over the chamber but mean fibre diameter was unchanged. Heating produced a small decrease in mean fibre diameter, but no change in mean length growth rate. Heating appeared to produce a slight reduction in pigmentation of some fibres but neither heating nor cooling produced demonstrable changes in crimping.
The potassium Q/l relationships of soils given different K manuring
Authors: Addiscott T. M.
Published: March 2009

The potassium quantity/intensity (Q/I) relationships, which relate change in exchangeable K content (Q) to change in activity ratio were measured in soil samples from manuring experiments at Rothamsted and Woburn. Within each experiment, Q/I curves for different K-manuring treatments were super-imposable on each other and on the curve relating exchangeable K to Io, the activity ratio at which the soil neither gains nor loses K. The distances on the Q axis between the curves were equal to the differences in exchangeable K.

The buffer capacity, dQ/dI, was related to the K saturation of the cation exchange capacity (CEC) by the equations

(Q and CEC in m-equiv/100 g)

Broadbalk and Hoosfield soil, and

for Barnfield soils (b= 3·08; m= 1·0) and for Woburn market garden soils (b =2·41; m= 0·6) but for soils from other Woburn experiments, dQ/dl did not vary significantly with Q/CEC.
Urinary phosphate excretion in the dairy cow
Authors: Manston R. , Vagg M. J.
Published: March 2009

Analyses of cow urine showed that about 10% of housed cows excreted phosphate greatly in excess of ‘normal’. The phosphaturia only occurred when the cows were permanently housed. No high phosphate concentrations were found in. urines from grazing cows although a significant increase in phosphate concentrations occurred when these cows were temporarily transferred to housed conditions.

No significant differences were detected between the high and low phosphate excreting cows with respect of urinary concentrations of creatinine, calcium, or chloride, urine specific gravity or pH, or plasma concentrations of calcium, inorganic phosphate, magnesium, sodium, potassium, alkaline phosphatase, chloride or bicarbonate.

Complete phosphorus balance measurements on four cows during the last six weeks of pregnancy showed that an increase in urinary phosphate excretion occurred in both high- and low-phosphate excreting cows when a dietary 'steaming-up' schedule was employed, and that the phosphaturia was accompanied by an increase in absorption of dietary phosphorus.

The cause of the phosphaturia does not appear to be acidosis. Little change in urinary phosphorus excretion occurred after oral doses of ammonium chloride but some increase occurred after equivalent doses of sodium and potassium carbonates. It is concluded that a small proportion of cows have a tendency to excrete relatively large amounts of phosphorus in the urine but that this only occurs under housed conditions.
Nutritional stress and pre-implantation mortality in Merino sheep, (1964–7). General discussion and conclusions
Authors: Edey T. N.
Published: March 2009

Collation and re-analysis of the results obtained in separate experiments investigating prenatal mortality in Merino ewes over a period of 4 years have made it possible to draw the following general conclusions:

Data from the control groups indicated that in 3 out of 4 years basal prenatal loss averaged approximately 25%, which agrees with a number of other estimates in the literature. Higher losses of ova in 1965 than in the other 3 years could not be partitioned accurately between fertilization failure and prenatal mortality.

Submaintenance nutrition apparently caused embryo mortality in 1964, and possibly in 1967, when underfeeding from day 7 to 37 was followed by an unusual number of long cycles; however, there was no evidence of increased mortality in 1965 and 1966.

Losses of ova shed as twins were significantly greater than amongst those shed as singles in 1964 and 1967. The higher loss of twin ova was clearly associated with the treated groups in 1964.

In each of the 4 years the left ovary produced more ova than the right, and when the 4 years' data were combined, survival of ova shed by the left ovary was significantly better than of those shed by the right. The type of twin ovulation, i.e. whether the two ova came from one ovary or two, had no consistent effect on prenatal mortality.

In 3 years there was no significant regression of prenatal mortality on body weight at mating. However, in 1965, when body weights were relatively low, there was a significantly negative regression. It is possible that there is a critical body weight below which poorer prenatal survival can be expected.

Ewes which suffered embryonic loss followed by a delayed return to service subsequently conceived less readily than those having a cycle of normal length following fertilization failure or early embryonic death. It is postulated that in some cases this may be because ovulation occurs while resorption is still incomplete. For some ewes having long cycles after embryonic death, anoestrus or removal of the fertile rams precluded subsequent conception in that season. This was an added reason for the season's lambing performance of ‘long cycle’ ewes being much worse than that of ewes re-mated after normal length cycles.
Seasonal and diurnal variations in body temperatures of Hereford and Brahman cross cattle in a cool temperate environment
Authors: Moran J. B.
Published: March 2009

Kendall (1948) suggested that the ability of cattle to thrive in tropical regions could be better indicated by the diurnal variation in body temperature rather than actual body temperature. However, Bligh & Lampkin (1965) found little difference in the nychthemeral variation in deep-body temperature of East African Zebus and Herefords grazing under conditions where the atmospheric shade temperature varied from 71 to 40 °F.
Metabolism of the soluble carbohydrates of grasses in the rumen of the sheep
Authors: Thomas Gwen J.
Published: March 2009

1. The bacteria and protozoa from the rumen of the sheep have been examined for their invertase activity.

2. Washed suspensions of protozoal fractions obtained from the rumen were rich in invertase, and the greater part of the total activity in the rumen could be ascribed to the holotrich protozoa.

3. Rumen streptococci capable of fermenting sucrose and fructan were isolated in pure culture. Their invertase was found to be an adaptive enzyme.

4. Fermentation of the soluble carbohydrates of grass was studied in an ‘artificial rumen’. The micro-organisms converted 30% of the substrates into storage starch.

5. Rumen contents from a grass-fed sheep were twice as active towards grass carbohydrates as those from hay-fed sheep.

6. The hay and grass fed to the sheep contained invertase activity.
Some genetic implications of maternal effects—an hypothesis of mammalian growth
Authors: Dickinson A. G.
Published: March 2009

In a cross-breeding experiment involving all types of matings among Friesian, Ayrshire and Jersey cattle, the effect of maternal size has been investigated, based on various comparisons of reciprocal crosses, using data on weight and body size from birth to 2 years of age. Among the thirteen characters analysed, there was a close relationship at I month old between the relative maturity of the characters and the relative extent of their maternal effects. This relationship showed that the more mature characters were the least affected by the maternal environment. Cross-bred calves out of a mother of the larger breed were larger at birth than the reciprocal crosses but in all cases this difference disappeared during the first year's growth.

The early expression of the offspring's genotype for body size depended on whether prenatal growth had been favoured or restricted by the maternal environment within limits. Maternal retardation of growth resulted in neonatal phenotypes closely related to their genetic ranking for mature body size, whereas early expression of the genotype is obscured by lavish prenatal conditions.

A mammalian growth model is presented and the results are interpreted in terms of this model. The explanation assumes that temporary advantage is taken, during growth, of variations in the environment, when the latter exceeds a minimal level demanded by the genotype for stable development to normal mature size. This supply and demand hypothesis of growth is discussed in terms of its implications for genetic selection of different types of body characters. The main conclusion is that an understanding of the early environment, particularly the maternal one, may permit selection for some adult characteristics to be carried out at an early age.
Nitrification of urea and its loss through volatilization of ammonia under different soil conditions
Authors: Wahhab A. , Khan Mahmud , Ishaq M.
Published: March 2009

Nitrification of urea and its loss through the volatilization of NH3were studied under different soil conditions. Under all conditions less urea was nitrified and more time was needed for its nitrification in sandy than in sandy loam soil. Nitrification was favoured at lower concentration of urea, onethird moisture of the moisture-holding capacity and at neutrality or the alkaline pH.

Loss of NH3was found to be twice as much from the sandy loam as from the sandy soil. It was also found that half of the total loss occurred during first drying. Loss of NH3from urea was found to be proportional to its concentration. The loss increased with the increase in soil moisture and temperature; but it decreased with the decrease in pH on the acid side and the increase in depth of its placement.
Cytological characteristics and fertilizing capacity of bull spermatozoa
Authors: Campbell R. C. , Hancock J. L. , Shaw I. G.
Published: March 2009

1. Two methods were used to estimate the frequencies of nine morphological classes of spermatozoa in 257 ejaculates from one Guernsey, five Friesian and seven Hereford bulls at an insemination centre. In nigrosin-eosin stained preparations and in fixed wet preparations the respective mean frequencies (%) were: malformed heads, 1·08 and 0·98; malformed middle pieces, 0·88 and 0·89; bent tails, 3·92 and 4·56; coiled tails, 0·60 and 0·43; free heads, 3·72 and 2·63; free tails, 1·79 and 1·85; neck beads, 0·87 and 0·93; middle-piece beads, 4·91 and 6·83.

2. There were close correlations between the two sets of measurements, but the differences of means were significant for free heads, bent tails, coiled tails, neck beads and middle-piece beads.

3. The mean percentage of dead (eosinophil) spermatozoa was 21·0.

4. The variations in the frequencies of each morphological class and of dead spermatozoa were divided within and between samples, ejaculates, bulls and breeds. The frequencies of all classes differed significantly between ejaculates within bulls; all but broken necks differed between bulls within breeds, and the Friesian and Hereford bulls differed in the frequencies of malformed heads, free heads, malformed middle pieces, free tails, neck beads and dead spermatozoa. The frequencies of bent tails, coiled tails and dead spermatozoa declined significantly with order of ejaculate.

5. The interrelationships of the frequencies of each class were examined. Two new methods used to measure the dead-sperm content of semen were shown to give results significantly correlated with those obtained by the conventional staining method and with motility ratings.

6. The interrelationships of measurements of the individual characteristics and conception rate were examined. Within-bull variations in conception rate showed a significant positive correlation (P < 0·05) with the frequencies of malformed heads and free heads. The between bull variation in conception rate showed a negative correlation with the frequency of neck beads (P < 0·05).
Dietary effects on beef composition: I. Quantitative and qualitative carcass traits
Authors: Garrigus R. R. , Johnson H. R. , Thomas N. W. , Firth N. L. , Harrington R. B. , Judge M. D.
Published: March 2009

Suppressed development of edible portion in carcasses from cattle fed hay during the early feeding period (216–340 kg live weight) was followed by compensatory growth during the intermediate (341–409 kg live weight) and final (410–454 kg live weight) periods. However, when silage in the early feeding period was followed by corn concentrate in the intermediate period, no increased ‘edible portion’ development was achieved beyond that produced by continuous silage. The final feeding period (corn concentrate) resulted in a decline in ‘edible portion’ percentage in cattle that previously received concentrate in the intermediate period whereas those that previously received silage remained at about the same percentage.

Cattle fed hay during the early period had less (P > 0·01) carcass weight, less (P > 0·01) fat cover, and more (P > 0·01) reticulo-rumen weight than those fed corn silage for the same period, regardless of slaughter weight.

In the heavy (409 and 454 kg) slaughter groups, cattle fed silage in the early period had higher (P > 0>05) marbling scores than those fed hay. Feeding silage in the intermediate period resulted in lower colour (P > 0·01) and firmness (P > 0·01) scores in the longissimus dorsi muscle than feeding concentrate at that time. The dietary regimes used in these studies resulted in widely varying growth rates among treatments with consequential differences in the average age of the animal groups at slaughter. Therefore, the treatment effects observed seem to be easily explicable on the basis of age differences.
The relationship between water and food intakes of european and zebu type steers
Authors: Phillips G. D.
Published: March 2009

1. The ratios of water drunk:hay eaten were studied for groups of Zebu and grade Hereford steers.

2. In all comparable conditions the ratio was significantly smaller for the Zebus.

3. Restricting water availability to about half significantly reduced the ratios for both types of steers.

4. The decrease in hay eaten resulting from restriction of water was less for the Zebus.

5. Restricting the hay intake to approximately half significantly increased the ratios for both groups.

6. The Zebus drank significantly less water than did the grades in relation to body weight.

7. It is concluded that the results of water restriction may not be as disastrous as would have appeared likely from the constant ratio relationship of water and food intakes previously suggested, particularly in the case of the Zebu steers who have been shown to be better adapted to dry conditions.
The effect of fallow hoeing on cotton yields in rotations in the Sudan Gezira
Authors: Ferguson H. , Kordofani A. Y. , Roberts P.
Published: March 2009

The average yields of irrigated long-staple cotton in the three-course rotations: dura, fallow, cotton, D-F-C; lubia, fallow, cotton, L-F-C; and fallow, fallow, cotton, F-F-C, were studied over 12 years in an experiment in the Sudan Gezira; the fallows (resting land) were either hoed or were left uncultivated during the rainy season, so that the effects of the operation of hoeing on the subsequent cotton yields could be measured.

Where the fallows were unhoed L-F-C yielded more cotton than F-F-C, which gave at first higher yields than D-F-C, although this difference had disappeared by the end of the period. Fallow hoeing increased yields in all rotations; this response was maintained in D-F-C and L-F-C. In F-F-C the response to hoeing either fallow diminished steadily in time and whilst the higher response to hoeing both fallows also decreased, its rate of decrease was no greater than when only one fallow was hoed. The response to hoeing fluctuated considerably from year to year. In all rotations these fluctuations were associated with rainfall and the relationships have been expressed in the form of regression equations; separate equations were necessary for each rotation as the relationships were quite distinct.

The variety X1730 A out-yielded Domains Sakel. There were interactions between the varieties and the other treatments, but these interactions were such that the varieties differed more at higher levels of yield and did not modify the above conclusions appreciably.
The effect of supplemental fat on the digestibility of the carbohydrates in compounded poultry diets
Authors: Bolton W. , Murty V. N.
Published: March 2009

1. The digestibility of diets supplemented with fat has been investigated.

2. For adult fowls and young chicks an increase in the fat content was accompanied by a decreased digestibility of the supplemental fat.

3. Supplemental fat depressed the digestibility of the carbohydrates when added to a chicks' diet, but had no such effect on a layers' diet.
The potency of balancing interactions between dietary proteins. Chick experiments on the significance for prior judgement and use of herring proteins
Authors: Laksesvela B.
Published: March 2009

1. The potency of balancing interactions between the protein of herring press-cake (dried) and solubles (condensed) on one side, and certain vegetable feeds on the other, has been examined on 2- to 4-week-old chicks:

(a) Initially by comparing the co-effect of a series of different combinations of the herring products when ingested together with certain cereals plus extracted ground-nut meal, to that estimated earlier when the same combinations of herring products formed the sole dietary protein.

(b) Thereafter by studying whether the co-effect of the herring products was influenced or not by substituting extracted soya-bean meal for the ground-nut meal.

(c) Further by tentative trials to show that registered interactions were caused by some keystone amino acids.

2. A special dietary system was devised for the purpose (a basal diet of actual feeds + a synthetic, practically protein-free basal diet + the tested feed, eventually + adjustments), the results being recorded as combinative protein value = c.p.v.

3. Interactions between dietary constituents not only were shown under the circumstances, but proved to be an easily acting factor of great power. Herring solubles in proportions of 15–45% were formerly found to bring about a statistically significant improvement of the meal when fed together with this as the only protein of the diet. But: (a) the introduction of certain cereals and ground-nut readily converted the beneficial effect of the solubles into a significantly negative one. (b) Whereas soya-beans instead of ground-nut evidently reversed the situation again. In this third grouping solubles at moderate levels appeared neutral, meaning that herring solubles combined significantly better with soya-bean than with ground-nut when fed to young chicks in presence of a set of cereals and herring meal, (c) Responses to supplemental, crystalline amino acids showed that the interactions between the protein sources could be attributed to their constituent amino acids. Thus the little efficient combination of solubles and ground-nut plus certain cereals could be greatly improved by small quantities of all ten essential amino acids together, and equally much by lysine plus threonine only. Contrarily, the diet appeared weakened when lysine, threonine or isoloucine were omitted singly or together from the whole ten. The same was the case with single addition of leucine.

4. The discussion stresses the pre-eminent importance of the diet in biological estimations of protein value. It also points out the practical significance of skilful combination of different protein sources.
Effects of egg-yolk-citrate and egg-yolk-glycine dilutors on the morphology of bovine spermatozoa
Authors: Mukherjee D. P. , Dott H. M.
Published: March 2009

Twenty semen samples were collected by means of the artificial vagina from three Friesian and two Dexter bulls. In each sample, thehead lengthandhead breadthof spermatozoa which did not take up the nigrosin-eosin stain, and their percentage before and after 72 hr. of preservation in egg-yolk-citrate and egg-yolk-glycine, were studied. The following results were obtained from the study:

1. No significant variation was found in the two measurements of sperm head before and after preservation in E.Y.C.

2. Both thehead lengthandhead breadthof spermatozoa preserved in E.Y.G. were significantly less than those before and after preservation in E.Y.C..

3. The change in size of the spermatozoa head in E.Y.G.. dilutor may be due to an alteration in the acrosome.
A comparison of the vegetative growth, development and seed yield of three varieties of cowpea, Vigna unguiculata (L.) Walp.
Authors: Ojehomon O. Ojeaga
Published: March 2009

The vegetative growth, flowering and seed yield of three cowpea varieties—Adzuki, Mala and New Era—with contrasting yields, were compared in one field and two greenhouse experiments. In the field the plants were spaced so far apart that they did not form a closed stand, but were effectively individuals, like the potted plants used in the greenhouse experiments. In all experiments New Era yielded most followed by Mala, although the differences between these two varieties were not significant, and Adzuki least.

Seed yield and vegetative growth were not simply related. New Era with the highest seed yield had the largest vegetative dry weight, leaf area and leaf area duration (D), followed by Mala, with Adzuki always least in each parameter. However, the superiority of New Era in total dry weight and leaf area was much greater than in seed yield. Mala and Adzuki were more efficient than New Era in converting dry matter into seed. Large fractions of current assimilates moved from the leaves to the seed of Adzuki and Mala than of New Era.

Varietal differences in relative growth rate, net assimilation rate, or leaf area ratio were too small to account for varietal differences in seed yield.

New Era and Mala produced more flower buds than Adzuki. However, Adzuki developed the largest proportion of ripe fruits, but had more aborted seeds/fruit than New Era and Mala. Thus, increased flower production and fruit formation did not increase the production of mature seeds. Therefore, little would be gained by breeding or selecting for increased flower production. The heavier seeds of Mala and New Era compared with those of Adzuki contributed greatly to their larger yields. At the spacing of 3 ft x 1 ft used in the field, the leaf area index (L) and leaf area duration (D) were suboptimal, and closer spacing should increase yield.
Changes in egg shell thickness and white and yolk weight and composition over a period of a year
Authors: Jenkins N. K. , Tyler C.
Published: March 2009

A study has been made of all eggs laid over a year (March-March) by twelve birds.

It was found that:

1. Shell thickness, yolk weight and white weight all increased with time.

2. For each individual bird a linear relationship existed between yolk weight and yolk calcium weight and between yolk weight and yolk phosphorus weight.

3. High calcium diets significantly increased shell thickness at the beginning of the experiment and yolk calcium around the middle of the experiment. Dietary calcium levels had no other effects and dietary phosphorus levels no effects at all.

4. The ‘curves’ relating shell thickness and time for each individual bird are discussed in relation to the relative merits of different birds as producers of thick shells.
Fission products and the dairy cow IV. The metabolism of 131I following single and multiple doses
Authors: Garner R. J. , Jones H. G.
Published: March 2009

1. The change in concentration of 131I with time in plasma, urine, milk and the thyroid gland has been followed in four cows after administration of either a single oral dose or of 131I from a decaying source every 6 hr. for 14 days.

2. The observed changes in concentration following multiple doses have been compared with those predicted from the single-dose experiments.

3. Small discrepancies were observed between the observed and predicted course of events in urine, milk and the thyroid gland: their significance is considered to be doubtful.
Labour saving in the feeding of sows
Authors: Barber R. S. , Braude R. , Hosking Zena D. , Mitchell K. G.
Published: March 2009

For 8 weeks after farrowing, sows were fed their standard ration (depending on the number of piglets being suckled) in either thirteen or fourteen feeds per week. The omission of one feed per week did not affect the performance of the 3-week-old litters whether reared indoors or outdoors. The response of the 8-week-old litters to sow-feeding system, however, appeared, from the limited data available, to be inconsistent over rearing environments, those reared outdoors being more affected by feeding system than those reared indoors. The outdoor reared litters consumed significantly more creep feed and were significantly heavier at 8 weeks of age than litters reared indoors, confirming previous observations. During the suckling period the sows lost on average 74·4 lb. in weight; weight loss was not influenced by environment or feeding system.
A study of various chemical treatments to remove lignin from coarse roughages and increase their digestibility
Authors: Chandra Suresh , Jackson M. G.
Published: March 2009

Several delignifying agents, used in various paper-making processes, have been compared for their ability to remove lignin and increase the digestibility of several roughages in laboratory experiments using a spray method of treatment recently suggested by Wilson & Pigden (1964). The chemicals were dissolved in small quantities of water which were then used to moisten the roughage. No washing was done after treatment. Sodium hydroxide was the most effective chemical; at a rate of 10 g per 100 g of roughage, the lignin content of ground maize cobs was reduced by 26% and rumen dry-matter digestibility increased by more than 100%. Bleaching powder was as effective as sodium hydroxide in removing lignin, but residual chlorine apparently inhibited rumen microbial digestion.

Maize cobs, wheat and paddy straws, sorghum stover and sugar cane tops, though of widely differing initial digestibility, were brought to an equal level of rumen digestibility if treated with 4% or more of sodium hydroxide. Drying the treated roughage at 100 degrees instead of at room temperature increased digestibility only in the case of maize cobs. The alkali spray treatment was as effective in increasing the digestibility of chaffed as of ground wheat straw. Data are presented which show the amounts of residual alkali in treated roughage as a function of time after treatment and of concentration of alkali used in the treatment. Further, data are presented which show the loss of nutrients from treated roughage if washed as in the traditional method.
The digestion of bacterial mucopeptide constituents in the sheep: 1. The metabolism of 2, 6-diaminopimelic acid
Authors: Mason V. C. , White F.
Published: March 2009

1. In a series of experiments with cannulated lambs the amounts of 2, 6-diaminopimelic acid (DAPA) and a-amino nitrogen passing daily through the abomasum, terminal ileum and rectum were measured. While there was a very significant net absorption of α-amino nitrogen between the abomasum and terminal ileum, there was no net absorption of DAPA between these points. Indeed, there was a tendency for more DAPA to leave the terminal ileum than entered the abomasum, though this was only significant at the 10% level. In all cases significantly less DAPA passed out of the rectum than passed through the terminal ileum, indicating extensive degradation of this amino acid in the hind-gut, probably as a result of microbial activity.

2. In adult sheep given control rations no DAPA could be detected in the blood, even when 643 ml plasma were analysed. These sheep usually excreted less than 5 mg DAPA daily in the urine.

3. When synthetic DAPA was introduced into the peritoneum, blood, abomasum, rumen or caecum of cannulated adult sheep in physiological amounts, approximately 80, 83, 53, 5 and 0 % of the administered dose was recovered in the urine. Furthermore, when introduced into the abomasum, DAPA could be measured in plasma from the anterior mesenteric and jugular veins.

4. It was concluded that in the normal sheep the DAPA-containing fraction of the bacterial cell-wall material synthesized in the rumen is not digested in the small intestine. In the caecum and colon, however, this fraction is extensively degraded by hindgut bacteria.
The relationship between soil phosphorus and response by sugar beet to phosphate fertilizer on mineral soils
Authors: Draycott A. P. , Durrant M. J. , Boyd D. A.
Published: March 2009

Results of two groups of experiments testing phosphate fertilizer for sugar beet were re-examined; there were 53 experiments made between 1957 and 1960 in group 1 and 25 experiments between 1957 and 1959 in group 2. The mean response of total sugar to 126 kg/ha P2O5 was only 160 kg/ha but on a few fields response exceeded 1000 kg/ha. Response seemed to be greater in 1958 than in the other years, but between-site variance accounted for most of the difference from year to year.

Stored soil samples were analysed for phosphorus by four methods; the results were compared and related to the yield response to phosphate fertilizer. After allowing for experimental error, the percentages of the between-sites variance of the responses accounted for by log (soil P) were (group 1 first): sodium bicarbonate, 60 and 62%; anion resin, 52 and 30%; ammonium acetate/acetic acid, 52 and 0%; and calcium chloride, 42 and 2%. When soil pH was included in the regression equation, prediction of response by anion resin much improved and equalled that of sodium bicarbonate. Ammonium acetate/acetic acid was ineffective on soils with much free calcium carbonate.

As two-thirds of the soils had sodium bicarbonate-soluble phosphorus concentrations between 15 and 45 ppm P with mean response 65 kg/ha sugar, there is only limited scope for increasing the profitability of the crop by improving P manuring. However, more P fertilizer can be recommended for the few soils with ≤ 10 ppm P and P fertilizer can be withheld from fields with more than 45 ppm. The dressings we recommend are 180, 120, 60, 30 and 0 kg/ha P2O5 (approximately 1·5, 1·0, 0·5, 0·25 and 0 cwt/acr P2O5) on soils with ≤ 10, 11·15, 16·25, 26·45 and ≥45 ppm sodium bicarbonatesoluble P respectively.
Repeatability and heritability of persistency of lactation and initial milk yield in the Egyptian buffaloes
Authors: Asker A. A. , Bedeir L. H.
Published: March 2009

The aim of this investigation was to study the repeatability and heritability of initial milk yield and persistency of lactation in buffaloes. The interrelationships between 305 days milk yield, initial milk yield and persistency were also investigated.
Nitrogen studies in a coffee soil II. The influence of mulch on natural and fertilizer levels of nitrate and ammonia in the top-soil
Authors: Robinson J. B. D.
Published: March 2009

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.
Nutrition and reproduction in the ewe
Authors: Allen D. M. , Lamming G. E.
Published: March 2009

1. A preliminary trial involving forty-six ewes demonstrated that when ewes in store condition were flushed for different periods, there was a marked increase in ovulation rate after 1 month with no further increase after 2 or 3 months. Flushing did not lead to ovulation rates higher than in ewes maintained in fat condition.

2. When similar ewes in fat condition were fed submaintenance diets there was no decline in ovulation rate while the animals had good body reserves, but as the period of submaintenance feeding was extended there was a gradual fall in ovulation rate.

3. In the main experiment forty-eight ewes were allocated to four groups of twelve ewes each. One group was fed a submaintenance diet till they were in moderately poor condition (submaintenance group). The other three groups were reduced to store condition and were then flushed on good pasture for 5–8 days, one oestrous cycle and two oestrous cycles, respectively. All ewes were slaughtered 2–5 days post-oestrus and half the ewes of each group were injected subcutaneously with 600 i.u. of P.m.s. on the twelfth or thirteenth day of the oestrous cycle prior to slaughter.
The nutrition of Zebu cattle Part III. Digestibility techniques: investigation of the effects of combination of dry faeces, length of digestibility trials and number of animals required
Authors: Bredon R. M. , Juko C. D. , Marshall B.
Published: March 2009

A method of combining dried faeces in order to reduce analyses of samples was investigated.

The effect of the length of digestibility trials and the number of animals required in relation to accuracy have been investigated and discussed.

As a result of our investigations the following procedure was adopted.
The development and function of the rumen in milk-fed calves II. Effect of wood shavings in the diet
Authors: Smith R. H.
Published: March 2009

1. Unmuzzled milk-fed calves which ate considerable amounts of wood shavings after they were a few weeks old showed a much bigger increase with age in volume of rumen fluid and in flow rate of fluid out of the reticulo rumen than did muzzled milk-fed calves. It is suggested that these differences were due mainly to increased saliva production in the calves eating shavings.

2. Milk leaked into the rumen at feeding in eight out of twenty-four experiments. There was no indication that shavings ingestion increased the incidence of leakage nor that age up to 16 weeks had any marked effect. The leakage appeared to be a consistent characteristic of certain calves rather than a random occurrence and did not appear to affect adversely growth or health.
The incidence of swayback among lambs with particular reference to genetic factors
Authors: Wiener Gerald , Sampford M. R.
Published: March 2009

The incidence of swayback among lambs in two flocks, previously reported, was reanalysed by a specially developed modification of the probit analysis technique in order to allow for the joint complications of an all-or-none trait and a large number of possible classifications for the animals in each flock. The form of analysis described yields predictions of the probability of swayback among lambs for the given circumstances.

Breed and sire within breed each affected the probability appreciably even when allowance for live weight of ewe and lamb was made. The effects of live weight, though significant in each flock, were not consistent in direction between the flocks. Other significant factors affecting swayback incidence were the manner of rearing the lambs, week of birth, and, in one flock, the sex of the lamb.
Infertile bulls versus steers: IV. Meat quality
Authors: Price M. A.
Published: March 2009

Meat quality comparisons were made between a total of 43 infertile bulls and 42 steers in five separate trials. Tenderness, juiciness and flavour were tested by taste panel for each of the five trials, making 15 subjective tests, while objective tests were made of tenderness (Warner-Bratzler shear) and juiciness (industrial press) in the five trials, making a further ten tests.

From this total of 25 different groups of assessments no significant difference between bull and steer meat was detected in 21; of the four groups of assessments where significant differences were detected, two favoured the bulls and two favoured the steers; the quality of all the samples was acceptable.

It is concluded from the overall results that in terms of practical meat quality there was no difference between the bulls and steers used in these five trials.
The relationship between various blood constituents of young Afrikaner bulls
Authors: Heyns H.
Published: March 2009

Considerable information is available in the literature concerning the levels of organic and inorganic constituents of blood of normal animals. It is well established that levels of many of these constituents are affected by season, age, breed, growth and other factors (Greatorex, 1957; Bhannasiri, 1960; Luitingh, 1962; Wilson, 1965). It is surprising, however, that little attention has been given to the relationship between these constituents of blood. Occasional reports on the relationship of a few constituents are available, but these were mostly studied in connection with the response of animals to a specific ration or certain ailment.
A study of the peat fenlands with particular reference to potato manuring
Authors: Pizer N. H. , Wright H. A. , Caldwell T. H. , Hargrave J. , Burgess G. R. , Cory V. , Boyd D. A.
Published: March 2009

Peat soils change gradually as a result of drainage and cultivation, losing depth through shrinkage, oxidation and blowing, changing in character through increases in mineral matter and ‘drumminess’, and changing in productivity and manurial requirements. The sequence of changes has been studied in the field and a number of stages distinguished which may be recognized quite simply from the texture of the ploughed layer. Texture is a field assessment of the type and condition of the peat and the proportion and nature of the mineral matter associated with it. The Fenland soils have been classified as follows: (1) peat soils, (2) peaty mineral soils, (3) organic mineral soils and (4) mineral soils. Further subdivision into textural classes depends on recognizing the mineral combinations or fractions as in texturing mineral soils

Analysis of samples of the ploughed layer in the laboratory has shown that organic matter or loss on ignition figures, expressed as a percentage of the oven-dried soil, can be used for recognizing the kind of soil; use is made of this in considering those earlier experiments for which organic matter figures could be calculated.
The availability of iron in certain grass, clover and herb species III. Burnet, chicory and narrow-leaved plantain
Authors: Raven A. M. , Thompson A.
Published: March 2009

1. The availability of iron in three herb species has been investigated, using the rat as the experimental animal.

2. Two procedures were employed, namely, the increase in blood haemoglobin concentration, and the gain in total grama of haemoglobin, by nutritionally anaemic rats.

3. Inorganic iron, as ferric chloride, was shown to be significantly more available than the iron contained in the three herbs.