bluuebunny/crossref_metadata_2025 huggingface dataset:
Reproduction in farmed red deer. 1. Hind and stag fertility
Authors: Hamilton W. J. , Blaxter K. L.
Published: March 2009

The fertility of a stock of red deer kept under farming conditions on hill land over a period of 7 years has been assessed. The stock consisted of five cohorts of hinds born in successive years from 1971 to 1975. The fertility of hinds was related to their body weight by the general relationship P = 1 – exp(– 0·085(W– 52)) where Pis the probability that a hind will calve and W is her weight in kg at the time of the rut. When body weight was taken into account in this way, age had no effect on hind fertility. Fertility was, however, poor in one year following a rut which occurred in bad weather. Separation of calves from hinds at the time of the rut had no effect on fertility, and under the farm conditions there was no increase in fertility of hinds which had been barren the previous year above that expected from their body weight. Date of calving was slightly skewed, but 63 % of all calves were born in the first 20 days of June. Smaller hinds calved later; 1 kg body weight increased date of calving by about 0·3 days. Evidence of stag infertility was obtained and it was shown that one stag could effectively mate with 28 hinds such that they mostly calved within a 20-day period. It was possible to run 60 hinds with three stags and obtain calving rates which were similar to those for the hind population as a whole. There were no differences in fertility between matched groups of hinds exposed to one or two stags. The results are compared with those obtained by observation of wild stocks in Scotland.
Growth and development of bush tomatoes in relation to temperature
Authors: Gray D. , Ward J. A. , Steckel Joyce R. A.
Published: March 2009

Data are presented relating various stages of growth of field-grown bush tomatoes cv. Sleaford Abundance established from dry and pre-germinated seeds and from transplants to accumulated day-degrees. In general, Ontario units predicted the dates of 50% flowering, of the first harvest and the date when 37·5 t/ha of ripe fruit had been picked, more accurately than day-degrees above 10 °C or calendar days. The number of Ontario units from sowing to 50% flowering for dry and pre-germinated seeds were 956 ± 35 and 871 ± 85, respectively. The corresponding figures from sowing to first harvest were 1958 ± 59 and 1867 ± 85. For transplanted crops the number of Ontario units from planting to 50 % flowering and from planting to first harvest were 322 ± 62 and 1352 ± 133, respectively. For transplanted crops the number of Ontario units required to give a yield of ripe fruit of 37·5 t/ha (the minimum level currently necessary on economic grounds for tomatoes for processing) was 1937 ± 112. Using this figure in conjunction with long-term meteorological records it was estimated that crops established from transplants at East Mailing, Kent (latitude 51° N), would fail to give yields of ripe fruit of 37·5 t/ha by late September on only 1–6 occasions in 100 whereas at Wellesbourne, Warwickshire (52° N) and Warsop, Nottinghamshire (53° N) crops would fail to reach this yield on 13–53 occasions in 100. Crops established directly from seeds would fail to give this yield on more than 50 occasions in 100 at all three sites.
The effect of changes in the intestinal flow of nucleic acids on allantoin excretion in the urine of Sheep
Authors: Antoniewicz Anna M. , Heinemann W. W. , Hanks E. M.
Published: March 2009

Three ewes were intraduodenally infused with yeast RNA (15, 20 and 30 g/day) or control solutions for 3 days and the net changes in urinary allantoin excretion determined. Four mature wethers fitted with a re-entrant cannula in the proximal duodenum were fed two levels (0·66 and 1 × maintenance) of pelleted lucerne hay. Allantoin excretion was compared with total nucleic acid (NA) flow in the small intestine.

The average proportion of the recovery of the infused RNA-N dose as urinary allantoin–N amounted to 0·119 ± 0·0046. The values of the net increase of allantoin-N (Y, g/day) above control levels were highly significantly correlated (n= 12,r= 0·98) with amounts of RNA-N infused (X, g/day):y= 0·1185 (± 0·0086)X–0·004 (P< 0·001). The average ratio of urinary allantoin-N to NA-N passing the duodenum during 24 h was 0·173. A difference between the two conversion factors is discussed in relation to endogenous allantoin excretion and purine base composition of yeast and bacterial RNA.
The digestibility of the carbohydrate complex of barley, wheat and maize by adult fowls
Authors: Bolton W.
Published: March 2009

1. The digestibility of the carbohydrates in barley, wheat and maize has been determined, using both conventional methods and individual methods for sugar, starch, pentosan, cellulose and lignin.

2. Sugar and starch were completely digested; cellulose and lignin were indigestible and the pentosan was about one-third digested.

3. Digestible pentosan accounted for about 3% of the total digestible carbohydrate.

4. The ratios of the available carbohydrate, i.e. the total of sugar plus starch expressed as starch, was almost exactly the same as that of the digestible carbohydrate and could be used as a measure of the relative amounts of digestible carbohydrate in the foods.
Studies on lucerne and lucerne-grass leys III. The effect of variety of lucerne and strain of grass
Authors: Ridgman W. J. , Hanley F. , Barker M. G.
Published: March 2009

1. An experiment comparing the growth and productivity of six varieties of lucerne representing a wide diversity of ecological conditions grown in association with S 37 Cocksfoot, S143 Cocksfoot and a commercial cocksfoot/timothy mixture is described and the results discussed.

2. Variety of lucerne had a marked effect on establishment, persistence, recovery from defoliation, early spring growth, yield of total dried produce, proportion of lucerne in that produce and on yield of nitrogen.

3. There was no evidence of differing degrees of compatibility of varieties of lucerne with the three strains of grass used.
Repeated backcrossing and hybrid vigour in poultry
Authors: Blyth J. S. S.
Published: March 2009

Using two inbred lines of Brown Leghorns, B and I, a backcrossing experiment was set up to test whether inherent rate of production was a simply inherited trait. Female progeny of each generation, selected for high rate, were mated to males of the B (lower rate) line. The pullet records now available, for 2 full years' production and to 31 March in the third generation, have yielded unexpected results.

In each backcross generation mean egg production has been at least as good as in the better parent, line I. This is not wholly accounted for by the behaviour of rate, since measurements of the trait in the cross approximate to the average of the two inbreds in each year. High viability and absence of very poor layers were also determining factors.

Backcross egg weight remained intermediate between the widely differing parent lines, and the cross produced the greatest total weight of egg material in each set of comparisons. Body weight was also intermediate, but sexual maturity was comparable with that of line B.

It was deduced that selecting the backcross breeding females for high rate had led to the retention of a greater proportion of the original I genotype than would normally have been expected, and so maintained continued heterozygosity in succeeding generations.

Practical implications of the results and interpretation are discussed.
Synthetic soil conditioners
Authors: Emerson W. W.
Published: March 2009

The ability of various high polymers to stabilize soil crumbs has been investigated using the sodium saturation technique. The soil used came from two plots on the Rothamsted classical fields, Barnfield and Hoosfield, which have received no fertilizer either organic or inorganic for 80 years, but whereas the former contains free CaCO3 the latter is acid.

The polymers tested were poly vinyl alcohol, sodium alginate, a vinyl acetate-maleic acid co-polymer, polyacrylic acid and a dextran. It was necessary to add 0·2–0·5% weight of the polymers in solution to the calcareous soil to produce crumbs of maximum stability, i.e. not dispersing the distilled water. The alginate, however, was effective only if the crumbs were first sodium saturated. With the acid soil, the amount of polyvinyl alcohol necessary for maximum stability was slightly reduced, corresponding to the lower clay content of the soil, whereas only one-tenth the concentration of the maleic acid co-polymer was required. Sodium alginate had no effect on the acid soil.

From the swelling pattern of the sodium-saturated crumbs in dilute salt solutions it was inferred that the non-ionic polymers, polyvinyl alcohol and the dextran form interlamellar complexes, whereas the carboxylated polymers are joined to the edge faces of the crystals. The presence of divalent cations is unnecessary for this edge linkage, as the polymers are equally effective when sodium ions only are present. It is suggested that the polymers form a series of hydrogen bonds with the exposed oxygen and hydroxyl atoms of the octahedral layer. Since these atoms have a greater tendency to co-ordinate a hydrogen ion as the pH is lowered, the carboxylated polymers would be expected to be more efficient on acid soils.

A simplification of the sodium saturation technique for the evaluation of potential soil conditioners is given.
Studies on the milk yields of Scottish Blackface ewes
Authors: Munro Joan
Published: March 2009

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.
Puberty in the buffalo-cow
Authors: Hafez E. S. E.
Published: March 2009

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.
Inter-breed ovum transfer in sheep
Authors: Hunter G. L. , Adams C. E. , Rowson L. E.
Published: March 2009

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.
The effect of testosterone and pregnant mare serum on semen production of rams of low libido
Authors: Ahmed S. I.
Published: March 2009

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.
Meiotic irregularities in hexaploid oats IV. Hybrids between Avena sativa (spring and winter varieties) A. fatua, A. sterilis, A. byzantina and A. nuda
Authors: Joshi A. B. , Howard H. W.
Published: March 2009

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.
Studies on soil humic acids: I. The chemical nature of humic nitrogen
Authors: Bremner J. M.
Published: March 2009

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.
Intervals of superphosphate application to downland permanent pasture
Authors: Norman M. J. T.
Published: March 2009

1. Superphosphate, at two levels and three intervals of application, was applied to calcareous downland pasture grazed by sheep over a period of 3 years.

2. At the high level, total dry-matter and crudeprotein yields were higher from a single initial application and from thrice-yearly applications than from annual applications.

3. At the high level, mean herbage phosphate content and total phosphate yield were higher following a single initial application than when superphosphate was applied at shorter intervals.

4. Superphosphate increased the cover of grasses and legumes and reduced the cover of herbs.

5. Superphosphate affected the cover of individual species in the following manner:

(a) Favourably: Dactylis glomerata, Festuca rubra, Arrhenatherum elatius, Poa trivialis, Holcus lanatus, Lolium perenne and Trifolium repens.

(b) Unfavourably: Agrostis stolonifera, Leontodon spp., Prunella vulgaris, and other minor herbs.

(c) No measurable effect: Poa pratensis, Plantago lanceolata, Ranunculus bulbosus and Crepis capillaris.
Subclinical copper deficiency in crops on the Breckland in East Anglia
Authors: Tills Alison R. , Alloway B. J.
Published: March 2009

Visible symptoms of copper deficiency in cereals have been observed in several parts of Britain and described by Caldwell (1971) and others. However, several cases have also been reported where yield increases of up to 20% or more have been obtained in response to copper treatment in several types of crops which did not show any symptoms of deficiency. These subclinical deficiencies are frequently not recognized under ordinary farming conditions where poor yields can often be ascribed to other causes, such as water stress. Copper applied as a foliar spray has powerful fungicidal properties but the yield responses discussed here were only due to the nutritional effects of the element. In trials with foliar applications of copper, Reith (1968) reported yield increases averaging 20% in oats and barley at different sites in Scotland on sandy soils formed on glacial drift.
Growth, development and yield of pigeon pea (Cajanus cajan (L.) Millsp.) in the lowland tropics:2. Effect of reduced assimilatory capacity
Authors: Tayo T. O.
Published: March 2009

In two field trials in 1980, 33, 67 or 100% of the leaves on pigeon pea (cv. Cita-1) plants were removed either at the vegetative stage, the onset of flowering, or at the rapid pod-filling stage, in order to evaluate the effect of reduced assimilatory capacity on the growth and yield characteristics of the crop.

Reduction in the assimilatory capacity of the plant led to significant reduction in the vegetative growth, dry-matter accumulation and seed yield of the defoliated plants compared with the undefoliated control such that 33, 67 or 100% defoliation led to 15–55, 40–60 and 75–80% reduction in seed yield respectively, at both trials. Also, defoliation was more damaging to crop performance if carried out from the onset of flowering than at the vegetative stage. Thus, the seed yields of plants defoliated at the onset of flowering and the rapid pod-filling stage were 30–80 and 40–45 % lower than the yield from plants defoliated at the vegetative stage in both trials.
Growth, development and yield of pigeon pea (Cajanus cajan (L.) Millsp.) in the lowland tropics:3. Effect of early loss of apical dominance
Authors: Tayo T. O.
Published: March 2009

In a pot experiment and two field trials, the apical portionof the main stem of a dwarf variety of pigeon pea (ev. Cita-1) was removed at 3 or 7 weeks after sowing in order to evaluate the effect of apical bud removal, during the vegetative stage of growth, on the subsequent growth, development and yield of the crop.

The early loss of apical dominance led, in all cases, to increased vegetative development, reduced plant height (except in one of the field trials), higher dry-matter accumulation and more pods per plant, with the treatment effect on number of pods being related to the number of branches developed. The yield of seeds was significantly increased by the early loss of apical dominance in the pot experiment and second field trial.

The results therefore show that an early loss of apical dominance, as could happen with insect and pest attack, may not be damaging to the vegetative growth and seed yield of pigeon pea under the prevailing lowland humid tropical conditions.
Control of Zn, Cu and Mn activities in alkaline and calcareous soils equilibrated with EDTA
Authors: Singh S. P.
Published: March 2009

The modified EDTA (ethylenediaminetetraacetic acid) method of determining the ionic activities in soils developed by Norvell was used to measure Zn2+, Cu2+ and Mn2+ activities including the competition of Ca and Mg for the chelating ligand EDTA. In the Zn-EDTA system, the equilibrium mole fraction of CaL2− + MgL2− increased with an increase in pH of the soil solution, thereby leading to a decrease in the concentration of transition metal ions. In view of the pH dependence of the metal ion activities, the values of the expression pM + 2 pOH (where M may be Zn, Cu or Mn) were used to discuss the possible role of various oxides, hydroxides, carbonates, sulphides and unknown solid phases in regulating the activities of Zn2+, Cu2+ and Mn2+ ions in alkaline and calcareous soils.
Evaluating methods of nitrogen application for efficiency of water use and yield of rainfed barley
Authors: Mahey R. K. , Cheema S. S.
Published: March 2009

Response of rainfed barley to different methods of nitrogen application was studied on a loamy sand soil in 1974–5 and 1975–6. The nitrogen fertilizer was applied by broadcasting, side drilling, drilling below the seed and in solution. In a year of lower rainfall, applying the fertilizer below the seed or in solution produced significantly more grain yield than broadcasting or side drilling. In a year of higher and well-distributed rainfall, applying the fertilizer below the seed was significantly better than other methods of nitrogen application. The magnitude of the response to applied nitrogen increased with increase of crop season rainfall and its better distribution. Placing N below the seed improved water use. It was followed in order by applying in solution, side drilling and broadcasting in both the years.
Coat colour in cattle: effect on thermal balance, behaviour and growth, and relationship with coat type
Authors: Finch Virginia A. , Bennett I. L. , Holmes C. R.
Published: March 2009

The effects of coat colours on thermal balance, behaviour and weight gain were studied. Measurements of thermal balance were made over 36 days in strong sunshine on highly contrasting coat colours of three white and three dark steers in each of two breeds, Brahman (B) and Shorthorn (S), and three light- and three medium-red steers in Brahman Hereford-Shorthorn cross breed (BX) where there was less contrast in coat colour. Each steer was measured for 30 min on six occasions randomly distributed among 6 h between 08.00 and 13.00 h, and on six occasions between 11.00 and 16.00 h, all on different days. For B, the difference between colours in mean rate of environmental heat gain at the skin was 64 ± 22·5 W/m2 and for S, 44 ± 20·5 W/m2, while the difference in mean rate of evaporative heat loss, between colours for B and S respectively was 44 ± 15·1 and 42 ± 14·3 W/m2. However, only within S was rectal temperature significantly higher in steers which were dark red and the reasons for this are discussed. Within BX the range of colour shades diminished during the experiment so thermal effects of colour were small. Colour had significant effects on growth; these effects were greatest in S where white steers gained 0·13 kg more per day than dark red ones. There were also differential effects within colour groups on activities at pasture; light steers spent more time in the sun and grazing than dark ones. In addition to colour, deep or woolly type coats negatively affected growth (P < 0·05), time spent in the sun (P < 0·05), and grazing time (P < 0·05); however, between animals within breeds the magnitude of the adverse effect of coat type on growth and behaviour was greater in dark- than light-coloured steers. These results provide evidence that coat colour is a trait which, interacting with coat type, exerts an influence on performance of cattle under heat stress.
Haemagglutinin extracts from raw, sprouting and differently processed limabeans
Authors: Ologhobo A. D. , Fetuga B. L.
Published: March 2009

The nutritional importance of a foodstuff in a diet depends on the composition of the raw foodstuff, the amount that is usually consumed and the extent to which nutrients are destroyed or lost during preparation of the diet.

Most Nigerian foods have to be prepared and cooked before they can be eaten. A lot of food preparation in Nigeria involves soaking, steeping, boiling, frying and roasting; at each stage of the preparation, some of the nutrients may be discarded or destroyed, while in some cases toxic substances may be discarded (Oke, 1968)
Genetic and phenotypic parameters of some measures of lifetime production and their relationship with milk yield in the first three lactations in Tharparkar cows
Authors: Taneja V. K. , Basu S. B. , Bhatnagar D. S.
Published: March 2009

The genetic parameters of lifetime production traits and their relationship with milk yield in first, second and third lactations were estimated from information on 753 Tharparkar cows. The heritability estimates for milk yield in first, second and third lactations were 0·22 ± 0·10, 0·33 ± 0·14 and 0·49 ± 0·17 and for number of lactations completed, lifetime milk production, number of days in milk and herd life 0·58 ± 0·23, 0·51 ± 0·22, 0·54 ± 0·22 and 0·34 ± 0·20 respectively. The genetic and phenotypic correlations among the four lifetime production traits were in the range of 0·83–1·0 and 0·84–0·85 respectively. The phenotypic correlations of milk yield in first, second and third lactations with lifetime production traits were significant and ranged between 0·15 and 0·56. The corresponding genetic correlations ranged between 0·26 and 0·83. For the first three lactations, the genetic correlations of lifetime traits with the third lactation were high and that between lifetime milk yield and yield in third lactation the highest (0·83 ± 0·17). The direct and correlated responses from single trait selection were also estimated.
A missing value technique for the analysis of data with repeated measurements on each experimental unit
Authors: Walters D. E. , Rowell J. G.
Published: March 2009

A missing value technique for the analysis of data where repeated measurements are taken on each experimental unit is proposed. The method suggested, which is a natural multivariate analogue of the well-known technique for univariate analyses, fits those missing values which minimize the determinant of the sums of squares and products matrix and provides the necessary downward adjustment to the residual degrees of freedom. A simulation exercise provides evidence that the method is fairly reliable.
The effects of monensin on the pool size and turnover rate of protozoa in the rumen of sheep
Authors: Leng R. A. , Nolan J. V. , Cumming G. , Edwards S. R. , Graham C. A.
Published: March 2009

The effects of including monensin in the diet on the dynamics of protozoa in the rumen of sheep were investigated using injections of protozoa labelled with14C-choline.

The half time of rumen fluid was higher in sheep receiving monensin but neither the pool size nor the composition of protozoa species (mainly smaller entodiniomorph ciliates) was significantly affected.

More protozoa passed out of the rumen as liquid outflow rate increased and there was a tendency for the apparent production rate of protozoa to be higher with the resulting increase in washout of protozoa.
The timing of nitrogen application for spring barley
Authors: Easson D. L.
Published: March 2009

Three experiments were carried out in which nitrogen was applied to spring barley (cv. Midas) either all in the seed bed or as a divided dressing with 10 or 25 kg/ha in the seed bed and 50 or 60 kg applied at emergence or 10, 20, 30, 40, 50, 60 or 70 days after emergence. Applying part of the nitrogen as a top dressing up to 30 days after emergence and 50 days after emergence had no significant effects on the grain and straw yields respectively, compared with applying all the nitrogen in the seed bed. Grain yields were progressively reduced with top dressings from 40 days after emergence (first node stage) onwards. Applications at 60 or 70 days did not give more grain yield than the no-nitrogen control, but gave straw yields which were intermediate between the no-nitrogen and seed-bed nitrogen treatments. Top dressing at 40 days after emergence stimulated tiller survival but did not improve grain yield because there were fewer grains per ear. Thousand-grain weights were lowest with top dressings at 50 days after emergence and grain nitrogen increased progressively with delay in top dressings from 30 days after emergence onwards.
The growth of three crisp lettuce varieties from different sowing dates
Authors: Wurr D. C. E. , Fellows Jane R.
Published: March 2009

Three American crisp lettuce varieties Ithaca, Pennlake and Saladin, formerly called Salinas, were sown on three occasions between April and July in 1980 and 1981 and on six occasions in 1982 between March and July. The rate of emergence of all three varieties increased with mean soil temperature at seed depth. The number of leaves was linearly related to air temperature measured on an accumulated day-degree scale > 0 °C from emergence. Pennlake had the highest rate of leaf production and Saladin the lowest rate. The relative growth rate of Ithaca increased with later sowing, while that of Pennlake declined. The time of maturity of one variety relative to another changed with sowing date but in all three varieties a quadratic curve relating the time of maturity to the time of sowing accounted for a high proportion of the variance in the time of maturity. When the times of sowing and maturity were both expressed on a day-degree scale > 0 °C a linear relationship accounted for more than 98% of the variance in time of maturity. These data provide the basis for planning a continuity programme. Within a variety there was considerable variation in mean head weight between sowings in the same year and different responses of head weight to sowing date from year to year. Using data from all 12 sowings, there was shown to be a significant association between head weight and the mean temperature up to 42 days from emergence but there was no association with radiation. Low mean temperatures (< 12 °C) were associated with lower head weights of Ithaca but higher head weights of Saladin. The opposite was true for mean temperatures greater than 16 °C. The reasons for this are discussed.
Evaluvation of artificially dried grass as a source of energy for sheep:II. The energy value of cocksfoot, timothy and two strains of rye-grass at varying stages of maturity
Authors: Armstrong D. G.
Published: March 2009

1. Four cuts of rye.grass S 23, three cuts each of cocksfoot S 37 and timothy S 48 and two cuts of rye-grass S 24 taken at different stages of growth and artificially (heat) dried were fed to mature sheep in a series of experiments designed to measure their value as sources of energy. The four cuts of rye-grass S 23 were each given to three sheep–two of the animals receiving it at five different levels of intake and the third at two levels. The other grasses were each given to four sheep at two levels of intake. The fasting heat productions of the sheep were measured at the beginning and end of the grass feeding periods. Altogether 152 experiments were made.
The effects of nitrogenous manuring, inter-row distance and method of sowing on the yields of a lucerne-cocksfoot ley
Authors: Hanley F. , Jarvis R. H. , Ridgman W. J.
Published: March 2009

1. An experiment designed to investigate the effects of heavy dressings of nitrogen, inter-row distance and ‘method’ of sowing on the yield of a lucerne-cocksfoot ley is described and the results discussed.
Effects of fluid drilling germinating onion seeds on seedling emergence and subsequent plant growth
Authors: Finch-Savage W. E.
Published: March 2009

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.
Oestrous activity of Suffolk, Mutton Merino and their crosses with subtropical Ossimi sheep
Authors: Aboul-Naga A. M. , Aboul-Ela M. B. , Hassan F.
Published: March 2009

Two trials were conducted to study the seasonal variation in oestrous activity over the year in Suffolk (S) or mutton Merino (M) temperate breeds, and their crosses with the local Ossimi (O) sheep under the prevailing subtropical conditions. In the first trial, groups of S, 75% S, 50% S, and O were used and the second trial involved groups of M, ¾M, ½M, ½M and O. The incidence of oestrus was measured by teasing with vasectomized rams. Suffolk ewes had a restricted period of oestrous activity (August–January) whereas M had a longer breeding season (August–March) with high incidence of long and double cycles. Local O showed irregular oestrous activity almost around the year, with particular decline in April. In both trials, all crosses had better oestrous activity than the pure parents, with the 50% S and the ½M having the best performance in the two trials, respectively. The period from September to February seemed to be the period of normal cycling activity in all breed groups, whereas the period from March to May was associated with marked breed-group variation in oestrous activity. Normal cycle length of the S was significantly (P< 0·01) shorter than the local O (16·0v.17·7 days) and was more consistent than other breed groups. In the two trials, normal cycle length of the cross-breds was ranked between the two purebred parents.
Energy and protein content and intake by stall-fed lambs of pure and mixed swards of Centrosema pubescens Benth., Pueraria phaseoloides Benth. and Brachiaria mutica Stapf. under a mango plantation
Authors: Asiedu F. H. K. , Karikari S. K.
Published: March 2009

Pure and mixed swards of Centrosema pubescens (centro), Pueraria phaseoloides (puero) and Brachiaria mutica (para grass) established under a 12-year-old mango plantation were sampled at 6-week intervals for 2 years to determine crude-protein (CP) content, dry-matter (D.M.) and CP yields and apparent digestible energy and apparent digestible crude-protein (DCP) contents. Daily dry-matter intake (DMI) and apparent digestible energy and digestible crude-protein intakes (DEI and DCPI), as well as live-weight gain (LWG) by 11·5 kg penned West African cross-bred weaner lambs, were also determined.

The pure legumes were better than the mixed swards in respect of CP (mean: 22·1, 18·8, 14·4 and 13·8% for centro, puero, centro-para grass and puero-para grass respectively) and DCP (mean: 16·2, 13·4, 10·4 and 10·0% respectively) contents, and daily DMI (mean: 50·8, 49·7, 41·8 and 41·3 g/kg W0·75 respectively), DEI (mean: 562, 531, 418 and 410 kj/kg W075 respectively) and DCPI (mean: 8·09, 6·55, 4·04 and 3·94 g/kg W0·75 respectively). On the other hand the legume-grass mixed swards, especially puero-para grass, were superior to the corresponding pure-legume swards with regard to D.M. yield (mean: 11·90, 7·69, 7·13 and 4·54 t/hafor puero-para grass, centro-para grass, puero and centro respectively) and CP yield(mean: 1·62,1·09, 1·32 and 0·99 t/ha respectively). The pure-legume stands gave the highest LWG per lamb (mean: 45·7, 3·89, 2·63 and 25·3 g/day for centro, puero, centro–para grass and puero-para grass respectively) but it was estimated that the legume-grass mixed swards would give higher returns in terms of lamb LWG on forages harvested per unit sward area than the corresponding pure-legume cover.

It was concluded that legume-grass covers would be preferred to all-legume covers if livestock were to be integrated into tree crop farming systems. However, the choice of companion grass would have to be given proper consideration as shade-intolerant grass species, such as para grass, would detract from profit maximization.
Effect of sowing date and cultivars of sorghum on infestation by Atherigona yorki, Sesamia cretica and Chilo partellus in Yemen
Authors: Ba-Angood S. A. , Hubaishan M. A.
Published: March 2009

Several introduced high-yielding varieties of grain sorghum were screened for natural infestation of shootfly Atherigona yorki Deeming, and stem borers, Sesamia cretica Led. and Chilo partellus (Swinhoe), at different sowing dates in 1980–1 and 1981–2 sowing seasons in People's Democratic Republic of Yemen (PDR Yemen).

The recently introduced high-yielding variety Dwarf White Milo (DWM) was found to be more prone to infestation by shootfly and stem borers than the local variety ‘Baini’ although it gave higher yield. All varieties tested gave higher yields when sown in March, August, September than when sown in April, May, October or November; 26 August and 16 September sowings gave the highest yields. B815, W823 and 8454 gave higher yields than the recently recommended high-yielding variety DWM, in response to lower infestation with the shootfly and stem borers; B815 and 8454 gave higher yields when sown on 26 August than when sown on 16 September. On the contrary, W823 gave higher yield when sown on 16 September than when sown on 26 August. This information could be used in formulating insect pest management programmes for sorghum pests in PDR Yemen.
The effects of direct drilling, shallow cultivation and ploughing on some soil physical properties in a long-term experiment on spring barley
Authors: Chaney K. , Hodgson D. R. , Braim M. A.
Published: March 2009

Physical measurements were made on the soil of a long-term cultivation experiment comparing direct drilling, tine cultivation and mouldboard ploughing for spring barley to investigate possible reasons for differences in yield. The soil was a typical argillio brown earth, approximately 90 cm of sandy clay loam topsoil and clay loam subsoil overlying magnesian limestone. For the three periods 1971–4, 1975–7 and 1978–80 the mean grain yields were marginally lower after direct drilling than after shallow cultivation or ploughing. There was an average decline in yield of 1·33 t/ha from the first to the last period, the decline being greater for direct drilling than the other two tillage systems. Although the surface horizon (0–5 cm) of direct-drilled soil had a higher content of organic matter than the ploughed, this did not increase the stability of the aggregates. Slaking tests had shown the soil to be inherently unstable and likely to suffer from structural problems. After the first 3 years bulk density of direct-drilled soil (0–15 cm) increased markedly toca.l·5 g/cm8and then remained relatively stable. In the ploughed soil, density increased steadily over the period to an average value of co. 1·45 g/cm8. Tine cultivation to 7–8 cm reduced cone resistance values in the surface compared with direct-drilled soil but below 15 cm there were no significant differences. Ploughing gave significantly lower values than direct drilling to a depth of 30 cm. Measurements of pore sizes in direct-drilled and ploughed soil were highly variable with few significant differences. Mean air capacity values (1978–80) tended to be lower in direct-drilled than in ploughed topsoil particularly for plots direct drilled after 7 years of deep tine cultivation. A limited number of root measurements in 1978 and 1980 showed that the length of root per unit of ground area was much less after direct drilling than after ploughing. Shallow cultivation, surprisingly, gave most root with a greater proportion of the root system below 20 cm than in the other two treatments. The classification of this soil according to its suitability for direct drilling cereals is discussed.
Studies on associative nitrogen fixation by antibiotic-resistant mutants ofAzospirillum brasilensewith genotypes of lentil (Lens culinaris)Rhizobiumstrains in calcareous soil
Authors: Rai R.
Published: March 2009

Nitrosoguanidine-induced mutation frequencies for resistance to streptomycin, spectinomycin, erythromycin and novomycin were studied inAzospirillum brasilense.Lentil inoculated withA. brasilenseand its mutants andRhizobiumstrains produced increased nodule dry weight, nitrogenase activity of nodules and roots and grain yield compared with an uninoculated control.
Viability of Litchi chinensis seeds when stored in air and in water
Authors: Ray P. K. , Sharma S. B.
Published: March 2009

India is the second largest litchi producing country in the world after China (Syamal & Mishra, 1984), yet the number of litchi cultivars grown in the country is quite small compared with mango (Mangifera indica). In mango most of the choicest Indian cultivars have been obtained from chance seedlings (Singh, 1960) grown in the past without any definite aim in mind. Litchi, as a result of crosspollination (Chaturvedi, 1965), is a highly heterozygous fruit, and as such, its seedlings, like those of mango, exhibit a wide range of variation which helps in the selection of new desired types. It has, thus, been emphasized that litchi should be grown in bulk from seeds to introduce genetic variability (Kumar & Thakur, 1981). Kadman & Slor (1974), encouraged by excellent success in grafting, have also stressed the need for raising plants through seeds for rootstocks.
Weed management in sorghum-legume intercropping systems
Authors: Abraham C. T. , Singh S. P.
Published: March 2009

The field experiments were conducted at the Indian Agricultural Research Institute, New Delhi in summer-rainy seasons of 1980 and 1981 to study the effect of different sorghum-legume intercropping systems and weed control methods on growth, yield and nutrient uptake by different crops and on weeds. The intercropping of legumes increased growth, uptake of N, P and K and yield of sorghum compared with sole sorghum. However, maximum increase was obtained when it was grown in association with fodder cow pea. All intercrops smothered the weeds but maximum suppression was by fodder cow pea. The total uptake of nutrients (N, P and K) was also greater in intercropping systems. Pre-emergence application of fluchloralin at 0·5 kg/ha was most effective in all intercropping systems followed by nitrofen at 1·0 kg/ha. Hand weeding and fluchloralin application also led to higher nutrient uptake by sorghum and the whole system than the unweeded control. Application of fluchloralin and nitrofen controlled most of the weeds and reduced nutrient removal compared with the control but was less effective than hand weeding.