bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic relationships between seed yield components and earliness in Vicia faba L. and the breeding implications
Authors: Poulsen M. H.
Published: March 2009

Data are presented on the relationship between seed yield, its distribution and the duration of growth. A plant model is proposed to achieve earlier ripening as well as high yield. The possibility of achieving this model is evaluated.

The F1 and F2 progenies of a complete diallel cross between seven inbred lines of field beans (Vicia faba spp. minor) were studied in order to elucidate the possibilities for breeding for earlier ripening without sacrificing seed yield. In a space-planted field trial the inheritance of and relationship among yield and earliness characters were examined.

On average the F1 generation was superior to F2 in seed yield as well as earliness of flowering and ripening. General combining ability (g.c.a.) effects were highly significant for all the characters studied and very high narrow-sense heritabilities were found for most characters. Specific combining ability (s.c.a.) effects were significant for all characters except for number of inflorescences, and significant reciprocal effects were found for seed yield and date of anthesis.

Because of the importance of g.c.a. effects, the phenotypic correlations were mainly determined by, and therefore similar to, the additive genetic correlations in showing a positive relationship between yield and the duration of pre- as well as postanthesis growth. However, a relatively strong negative non-additive genetic correlation was found between yield and duration of post-anthesis growth.

Path analysis showed that 70–82% of the variation in post-anthesis growth was accounted for by the distribution of seed yield described by four yield components, thus supporting the hypothesis that the duration of post-anthesis growth is highly dependent on the distribution and size of the seeds.

Two possibilities for breeding earlier-ripening, high-yielding cultivars are suggested: (1) exploiting hybrid vigour in terms of earlier ripening and (2) reducing the duration of post-anthesis growth byselecting for more seeds per pod and more pods per inflorescence.
Comparative retentions of fluorine and phosphorus by growing sheep given either defluorinated rock phosphate or dicalcium phosphate of different particle sizes
Authors: Hemingway R. G. , Finn Allison M.
Published: March 2009

A low phosphorus diet given to growing sheep in metabolism cages was supplemented with different sized fractions of either defluorinated phosphate or dicalcium phosphate. For material of particle size between 0·50 and 0·25 mm diameter, significantly less fluorine was present in the urine and more in the faeces of sheep given defluorinated phosphate than for those given dicalcium phosphate. The fluorine present in coarser defluorinated phosphate was of similar availability to that smaller than 0·50 mm. Finer grade defluorinated or dicalcium phosphates smaller than 0·25 mm diameter were not more biologically available in respect of either fluorine or phosphorus than those of particle size 0·50 to 0·25 mm. The availability of the phosphorus in defluorinated phosphate was reduced when material coarser than 0·50 mm was given to the sheep.
The use of electrophoretically labelled populations for intra-specific competition studies in perennial ryegrass (Lolium perenne L.) swards
Authors: Quaite Elsie , Camlin M. S.
Published: March 2009

Genotypes homozygous for specific PGI2 alleles were selected from four existing cultivars of different maturities, Gremie, Aberystwyth S.321, Barlenna and Melle. Each of three groups of plants (early BB selected from Gremie, intermediate CC selected from Aberystwyth S.321 and Barlenna and late AA selected from Melle) was isolated and allowed to interpollinate producing three experimental seed lots or populations. These populations, screened for their electrophoretic purity, were found to exhibit only the selected parental PGI2 genotype.

The three labelled populations were sown in boxes in September 1982 as monocultures, as all possible 50:50 mixtures, and as a three-way mixture to produce miniswards. Following one harvest in the establishment year these were harvested and dry-matter yields determined on a monthly basis from April to October 1983, two horizons in the sward being examined separately at harvests 1–5. Changes in the proportions of populations in each mixture were monitored by random subsampling of the cut herbage and subsequent electrophoretic testing.

The ability to dominate productivity in the top horizon in mixtures was dependent on the timing of reproductive development of any particular population. The patterns of productivity in the bottom horizon and in both horizons combined showed the early population dominating the mixed swards briefly at the beginning of the harvest but the late population dominating from June–July onwards. The intermediate population, although the most productive in monoculture, did not reveal any tendency to dominate productivity in any of the mixtures.

The potential use of electrophoretically labelled cultivars to study complex aspects of plant competition is discussed, along with the possible application of results from these studies to agricultural practice.
Relative effects of Azolla pinnata and its combination with chemical nitrogen fertilizer on growth, yield and N uptake of rice
Authors: Singh D. P. , Singh P. K.
Published: March 2009

Field experiments conducted during wet and dry seasons with Ratna and Jaya varieties of rice (Oryza sativa Linn.) indicated that the use of Azolla pinnata as fertilizer increased growth in terms of number of tillers, leaf area index, dry-matter production, grain yield, N uptake and its accumulation in different plant parts. Azolla incorporation before planting in addition to 30 kg N/ha produced higher grain yields of both the rice varieties than 60 kg N / h a during the two seasons, while Azolla grown as an intercrop with rice plus 30 kg N/ha was superior to the 60 kg N treatment in grain production of Jaya during the wet season. Azolla incorporation before planting and also once intercropped with rice produced more grain yield than 60 kg N during the wet season. Among Azolla treatments, Azolla twice intercropped with rice produced comparatively lower grain yield. Azolla application increased the number of panicles/m2, number of grains/panicle and reduced sterility during both seasons. The N uptake of the rice crop in the treatments of Azolla incorporation before planting or intercropped once with rice in combination with 30 kg N/ha was similar to that of the 60 kg N/ha whereas the treatment of Azolla incorporation before planting plus once intercropped was similar during the wet season only.
Water deficit during panicle development in pearl millet: yield compensation by tillers
Authors: Mahalakshmi V. , Bidinger F. R.
Published: March 2009

Water deficit during the panicle development stage reduced the grain yield of the main shoot panicle of pearl millet but this loss was compensated by increased grain yield of the tillers. The potential extent of compensation in grain yield components by tillers was investigated by removing the main shoot at panicle initiation (PI) and flowering stages respectively, for both irrigated and water-stressed plants. Grain yield loss by removal of the main shoot of plants at PI was fully compensated by tiller grain yield in both the irrigated and water-stressed plants. The compensation was, however, only partial when the main shoot was removed at flowering. The compensation for the grain yield loss in the main shoot due to either water stress or removal was through an increase in number of grains on the tillers. This increase was due to an increase in the number of productive tillers in the case of water stress and to both an increase in the number of productive tillers and an increase in the number of grains per panicle in the case of main shoot removal. This compensatory mechanism by tillers plays an important role in overcoming the effects of pre-flowering water stress damage to the main shoot.
Compensatory growth in immature sheep: I. The effects of weight loss and realimentation on the whole body composition
Authors: Drew K. R. , Reid J. T.
Published: March 2009

Forty-eight cross-bred wether lambs were used to measure the effects of severe feed restriction and realimentation on the body and carcass composition of immature sheep. Ten of the total number of sheep were used as an initial slaughter group, 12 were continuously fed (six at the ad libitum level of intake and six at 70% ad libitum), 26 were progressively underfed and 18 of them were realimented after a mean loss of about 25% empty body weight (EBW).

Shrunk body weight (SBW = weight after an 18-h fast with access to water) was a good predictor of empty body weight (EBW = SBW minus gastro-intestinal contents) and the EBW of continuously growing sheep was a good predictor of body water, protein, fat, energy and ash, but it was not precise after realimentation, particularly in the early stages of refeeding. Restricted continuous supermaintenance feeding did not alter the body composition of the sheep from that of the sheep on the ad libitum intake at any given EBW except slightly to increase the carcass protein content.

Although underfeeding to produce an EBW loss of 25% generally produced changes in the chemical body components which were similar to a reversal of normal growth, body fat did not decrease during the first half of the submaintenance feeding and did not increase during the first 2 weeks of realimentation. Under all circumstances percentage body fat was very closely related to percentage body water.

Sheep realimented at 26 kg (after losing 25% EBW) contained, at 45 kg EBW, more bodywater and protein and less fat and energy than continuously-fed animals of the same EBW. The treatment effects were greater in the carcass and had little effect on the non-carcass EBW, with th e result that the refed sheep had 1800 g more water × protein in a carcass that weighed 700 g more than one from a normally grown sheep of the same EBW. The regression of calorific value of th e ash-free dry matter on body fat as a percentage of ash-free dry matter gave calorific values of body protein and fat as 5·652 and 9·342 kcal/g of ash-free dry matter, respectively.
The growth of maize: III. The effect of date of sowing and bitumen mulch on dry-matter yields
Authors: Osafo D. M. , Milbourn G. M.
Published: March 2009

Experiments are described which analyse the effects of date of sowing and of a black petroleum soil mulch on the growth of two maize hybrids. The two hybrids used were Anjou 210, which is late maturing in S.E. England, and Kelvedon 75A, which is an early hybrid.

As sowing was delayed from mid-April until the end of May, so there was a greater development of vegetative tissue (mainly stem) and leaf area which reached peaks at a later stage after silking. In Anjou 210 early sowing led to higher grain yields (12%) as the production of peak vegetative weight near to the time of silking allowed dry matter produced after that stage, still at a time of high radiation, to move direct to the oars. Also, the remobilization of the secondary source of grain dry matter, namely previously stored photosynthate from the stem, occurred earlier with early sowing and to a greater extent when a longer grain-filling period was allowed.

The hybrid K 75A had a lower vegetative weight, and earlier silking coincided with higher levels of radiation, and the resultant increase in net assimilation rate led to a higher proportion of dry matter being partitioned into the ear. Because this hybrid flowered and senesced early, reserves of stem carbohydrate were low and the time available to transfer carbohydrate to the ear was short, resulting in lower yields than in the later maturing Anjou 210. K 75A also responded unexpectedly to the sowing treatments. Although late sowing gave higher grain yields in both hybrids up to 156 days after sowing, in the case of K 75 A, the early senescence curtailed the continuation of grain fill that would normally give early sowing an advantage and hence the late sown K 75 A produced 10 % more grain.

The application of a black petroleum mulch to the surface of the soil to raise soil temperature enhanced the benefits derived from early sowing. Plants given this treatment produced greater leaf areas and vegetative dry weights. As a result more carbohydrate was translocated from the stem during the grain-filling period, increasing grain yield by 13% following an increase in both number of grains and individual grain weight.
Components of test weight of ten varieties of winter wheat grown with two rates of nitrogen fertilizer application
Authors: Pushman Fiona M. , Bingham J.
Published: March 2009

Varietal and environmental factors which influence test weight were investigated in a field trial with ten varieties of winter wheat and two rates of nitrogen fertilizer. Varietal differences in test weight were correlated positively with the protein content of the grain and inversely with grain yield but they were not related to 1000-grain weight or to flour yield. Variation in test weight associated with varietal and environmental effects in protein content was due to differences in the density of the grain, as measured by displacement of xylene. Separation into density grades within a sample by a flotation method showed a similar relationship with protein content. There were also varietal differences in packing efficiency of the grain. In the case of Maris Huntsman a poor packing efficiency was considered to stem from morphological features of the floret and developing grain which lead to characteristic transverse folds in the ventral surface of the mature grain. For wheat grown in the United Kingdom, test weight may provide a useful guide to flour yield for samples of one variety but it is likely to be misleading for comparisons between varieties.
The effects of delayed planting and soil consolidation on potato yields
Authors: Beveridge J. L.
Published: March 2009

1. Two series of experiments designed to investigate the effects of delaying planting potato seed tubers after drawing ridges in preparation for planting and of consolidation of soil beneath seed tubers on the growth and yield of potatoes are described and the results discussed.

2. Delayed planting reduced the yield of saleable ware-size (> I¾ in.) tubers in one year by as much as 1.7 + 0.59 tons/acre, but had little effect in the other years, and it is argued that the effect was dependent on the tilth obtained in preparation for planting, the soil moisture content at the time the ridges were drawn, the amount of moisture lost during the delay period, and the rainfall after planting.
The effect of trienbolone acetate on glucose metabolism in normal and ketotic sheep pregnant with twins
Authors: Ford E. J. H. , Samad A. R. , Pursell Hilary
Published: March 2009

Normal and ketotio ewes pregnant with twin lambs were injected intramuscularly with 0·5 mg/kg body weight of trienbolone acetate. In the normal animals there was no significant change in the concentration of glucose, ketones, glycerol or NEFA in plasma.

Induction of ketosis by starvation produced a significant fall in the concentration of glucose in plasma and significant increases in the concentration of ketones, glycerol and NEFA. Trienbolone caused no further significant changes in the concentration of the four metabolites in the plasma of ketotio sheep.

Primed continuous simultaneous intravenous infusions of tracer amounts of [2-3H] and [U-14C]glucose were used to measure total entry rate and irreversible loss of glucose. Trienbolone caused significant decreases in both these measurements in normal pregnant sheep. Production of ketosis by starvation had the same effect. Trienbolone produced no significant additional effect in the ketotic sheep and no alleviation of the clinical signs of the hyperglycaemic ketosis.

These results are discussed in relation to the assessment of the potential value of trienbolone as a treatment of pregnancy toxaemia of sheep.
Effects of severe food restriction on bone growth and distribution in pigs
Authors: Carden A. E. , Goenaga P. R.
Published: March 2009

The effects of food restriction on the growth and distribution of bone and on the relation between changes in long bone lengths and changes in limb muscle proportions were studied in 32 Duroc Jersey barrows. Sixteen pigs were fed ad libitum (H group) whilst the other 16 received the same diet on a restricted scale related to live weight.

Animals in each group were slaughtered at times such that the weights of bone in their half carcasses were spread evenly over the range 1·5–4·O kg. The right half carcasses were completely dissected using strictly anatomical criteria.

The results on the relative growth of bone were examined by covariance analysis using the allometric equation.

After adjusting for equal weight of total bone in the side L pigs had heavier femur, tibia-fibula, humerus and radius-ulna and lighter scapula and ribs than H pigs.

Relative to their weights all appendicular long bones were longer in L pigs than in H ones, while there was no such effect on spinal column length.

The effects of the treatment on fore limb muscle proportions relative to total muscle were significantly correlated (P < 0·01) with the changes observed in the lengths of the long bones forming their osseus bases. However, in the case of the hind limb the regression and correlation coefficients were not significantly different from zero.
The development of plant components and their effects on the composition of fresh and ensiled forage maize: 1. The accumulation of dry matter, chemical composition and nutritive value of fresh maize
Authors: Phipps R. H. , Weller R. F.
Published: March 2009

Results from two trials, in which the effects of genotype, plant density and harvest date on the accumulation of dry matter and the chemical composition and nutritive value of plant components, are presented. Inra 200, LG11, Maris Saffron, Caldera 535, Anjou 210 and White Horse Tooth were established at 5·0, 9·8 and 13·5 plants/m2in factorially designed experiments.

In vitrodigestible organic matter in the dry matter, water-soluble carbohydrates, starch, total nitrogen, acid-detergent fibre, cellulose, lignin, phosphorus, magnesium, potassium, calcium, sodium, zinc, manganese and copper were analysed for the whole crop and plant components.

With the exception of White Horse Tooth, stem yields declined after reaching a peak 2–3 weeks after mid-silk. This was attributed to movement of water-soluble carbohydrates from the stem to the ear, with greater movement being associated with a larger ear component. As a result thein vitrodigestible organic matter in the dry matter value of the stem component was greater for crops containing a small proportion of ear. The higher stem digestibility value compensated for the small ear component, with the result that the varying proportions of plant components did not markedly affect whole-crop digestibility prior to ensiling.

The greater deposition of starch in crops with a large ear component caused a significantly more rapid rise in whole-crop D.M. content than in crops with a small ear component.

Acid-detergent fibre and lignin values for the whole crop were much lower than those recorded in the U.S.A. Genotype and plant density had no effect on mineral content but phosphorus and potassium concentrations declined dramatically after frost.
Anaerobic proteolytic bacteria in caecal contents of ponies
Authors: Reitnour C. M. , Mitchell G. E.
Published: March 2009

The numbers of viable anaerobic proteolytic bacteria were determined from the caecal fluid of three ponies fed diets based on maize, oats or barley. In anaerobic conditions selected to promote the growth of those bacteria capable of utilizing protein, between 2 × 105and 8 × 105of viable anaerobic proteolytic bacteria/ml of caeoal fluid were observed. Time of sampling post feeding did not appear to affect the numbers observed. These numbers would appear adequate to make an important contribution to protein digestion.
Male sterility in field beans (Vicia faba L.). II. Yield trials of F1 hybrid winter beans produced with the aid of male sterility
Authors: Bond D. A. , Fyfe J. L. , Toynbee-Clarke Gillian
Published: March 2009

1. F1 hybrids between inbred lines of winter beans were obtained by roguing male-fertile plants from segregating progenies of a genetic male-sterile line which had been interplanted with a pollinator.

2. In a series of trials the mean yields of many hybrids were significantly higher than those of open-pollinated varieties. Over the 4 years, 1959–62, with trials at three centres in each year, the mean advantages of all hybrids over the two control varieties was 6·4 cwt./acre over Gartons S.Q., 4·7 cwt./acre over Throws M.S.
The effect of heat treatment in the processing of groundnut meal on the value of the protein for ruminants with some additional experiments on copra
Authors: Chalmers Margaret I. , Jayasinghe J. B. , Marshall S. B. M.
Published: March 2009

1. Groundnut meals subjected to different degrees of heat treatment during manufacture were fed to lactating goats on nitrogen-balance experiment. The ‘toasted’ groundnut meal was more effective than undenatured or air-dried meals in promoting nitrogen retention.

2. The heat treatment of the groundnut meals did not influence the digestibility of the protein.

3. The groundnut meals were typed by determining their salt-peptizability giving values ranging from 44% for the ‘toasted’ meal to 80% for the air-dried meal.
Metabolism of the gravid uterus, foetus and utero-placenta at several stages of gestation in cows
Authors: Reynolds L. P. , Ferrell C. L. , Robertson Debra A. , Ford S. P.
Published: March 2009

To quantify changes in rates of metabolism and nutrient uptake of gravid uteiine, foetal and utero-placental tissues throughout gestation, mature Hereford cows received surgery at 132 ± 0·6 (n= 12), 176 ± 0·5 (n= 8), 220 ±0·4 (n= 11) and 245 ±1·5 (n= 7) days after mating. Indwelling catheters were implanted into a uterine artery and vein of all cows. Foetal catheters also were implanted into an umbilical vein and foetal femoral artery and vein (days 176 and 220) or into a placental artery and two placental veins (days 132 and 245). Approximately 5 days after surgery, deuterium oxide was infused into a foetal femoral venous or placental venous catheter during a 3 h period to quantify uterine and umbilical blood flows by steady-state diffusion methods. Oxygen, glucose, lactate and α-amino acid nitrogen concentrations were determined for uterine and foetal blood samples collected during this procedure.

Uterine blood flow increased 4·5-fold (2·92–13·181/min) and umbilical blood flow increased 21-fold (0·28–5·861–min) during the interval of gestation studied. The relative rate of increase of umbilical blood flow was about twice as great as that of uterine blood flow. Uterine arterial and umbilical venous concentrations as well as uterine arterial-venous and umbilical venous-arterial concentration differences in metabolites changed little with stage of gestation. However, because rates of blood flow increased, uptakes of O2, glucose and α-amino N by the gravid uterus and foetus increased as gestation advanced. The proportion of gravid uterine uptakes utilized by the foetus increased from day 137 to 226 for O2(24–58%) and from day 137 to 180 for glucose (4–19%), then remained relatively constant. The proportion of gravid uterine α-amino N uptake utilized by the foetus remained relatively constant and averaged 60%. A net secretion of lactate from the utero-placenta to the uterine and foetal circulations was observed and increased as gestation advanced. These data indicate that increased rates of uptake or secretion of metabolites by tissues of the gravid uterus can be explained primarily by increased rates of uterine and umbilical blood flows.
Comparative studies of sheep and goats: milk yield and composition and growth rate of lambs and kids
Authors: Economides S.
Published: March 2009

Two trials were carried out to compare the milk yield, milk composition and the rate of growth of naturally or artificially reared kids and lambs of Damascus goats and Chios sheep.

Milk yield until weaning was similar in sheep and goats, but goats produced significantly more milk after weaning. Sheep milk was higher in total solids, fat, protein, lactose, ash and calorific value.

Lambs and kids grew similarly during thead libitummilk feeding period but lambs grew faster during the restricted milk feeding period. Solid feed intake of lambs until weaning was higher than that of kids and the results indicated that the rumen develops later in kids than in lambs. During the post-weaning period lambs consumed more feed, grew faster and utilized feed more efficiently than kids. Lambs were more sensitive to high copper supply than kids.
Male sterility in field beans (Vicia faba L.). III. Male sterility with a cytoplasmic type of inheritance
Authors: Bond D. A. , Fyfe J. L. , Toynbee-Clarke Gillian
Published: March 2009

1. Male-sterile plants were discovered in the progeny of an open-pollinated plant which had undergone a much higher level of natural crossing than any of a group of fifty plants drawn from the same population.

2. Some male-sterile plants produced a few viable pollen grains under some conditions but these rarely permitted self-fertilization. A few plants had both sterile and fertile tillers. Male sterility was not transferred by grafting. No effect on the proportion of fertile plants could be found, when progenies were observed early and late in the season, sown in the autumn and spring or grown at contrasting plant densities.

3. Inbred lines, unrelated to the male-sterile plants and their derivatives, varied greatly in their ability to restore male fertility. Some lines maintained the sterility almost completely, two consistently gave all male-fertile offspring, but the majority were partial restorers.
The response of plasma minerals, free fatty acids and glucose to adrenaline and cortisol infusion in sheep
Authors: Bolton Sarah C. , Weekes T. E. C.
Published: March 2009

Adrenaline was infused at three rates, 40, 15 or 3 μ/kg/h, in normal sheep and in sheep rendered hypercortisolaemic by infusion of cortisol at 150 μg/kg/h. In both normal and hypercortisolaemic animals, plasma concentrations of glucose and free fatty acids were increased by adrenaline treatment; plasma phosphate decreased with all treatments; plasma magnesium and potassium decreased on infusion of adrenaline at 40 or 15, but not at 3 μg/kg/h; plasma calcium decreased only on infusion of adrenaline in hypercortisolaemic animals, and plasma sodium concentration was unaffected by treatment.

Induction of a degree of lipolysis likely to occur in the field was not associated with a marked decrease in plasma magnesium.
Hormone changes in milk at the onset of lactogenesis and parturition in Friesland sheep
Authors: Heap R. B. , Fleet I. R. , Hamon M. , Booth J. M. , Chaplin V. M.
Published: March 2009

Oestrone sulphate, progesterone, total protein, Na and K concentrations in mammary secretions of Friesland sheep have been determined from 11 days before until 8 days after parturition. Mammary secretions were obtained on most days for at least 1 week before parturition in 9 of 14 ewes, and in all animals after lambing. Oestrone sulphate concentration had doubled on the morning of parturition compared with the value 24 h earlier, and this sharp rise was a useful indicator that delivery was imminent. Values continued to rise during the day of delivery, remained high for a further 24 h and then declined over the next 2 days. Progesterone, in contrast, decreased linearly between day –2 and day +2 when it reached baseline values.

Total protein concentration in pre-colostral and colostral mammary secretion (10–15 g/100 ml) was higher than that in goats, and decreased to a mean value of about 6 g/100 ml by day +8 after delivery. Na declined from about 55 mM on day –10 to 36 mM on day 0, whereas K increased from 20 to 29 mM. There was a sharp rise in K/Na, but this occurred after rather than before parturition and was not a useful predictor of parturition.

The onset of copious milk secretion occurred when oestrone sulphate in mammary secretions was high and progesterone was low, which is consistent with the hypothesis that the cessation of progesterone secretion is an important regulator of the onset of lactogenesis in sheep. Efficiency of milk secretion in the first 14 days of lactation was correlated, however, with the maximum oestrone sulphate concentration in colostrum on the day of parturition.
Manganese-mediated resistance to aluminium and antibiotics in strains ofAzospirillum brasilenseand their interaction with rice genotypes in acid soil
Authors: Rai R.
Published: March 2009

Manganese-tolerant strains Mnr-1 and Mnr-5 ofAzospirillum brasilense(RAU 1075) were isolated through step-wise transfer to higher levels of manganese chloride. One of the strains (Mnr-5) showed more growth at low pH and greater nitrogenase activity in 10 mM MnCl2. 4H2O than parental and Mnr-1 strains. These tolerant strains also showed cross-resistance to antibiotics such as gentamycin and neomycin but not to streptomycin. Mn-adapted strains also tolerated elevated levels of aluminium (2·5–3·5 mg/kg) and the stability of the Mn-resistance required the presence of Mn2+ ions in the growth medium. It has been demonstrated that the effect of inoculation with Mn-adapted strains was variable with different genotypes of rice in acid soil and that initial low level of nitrogen was essential for maximum associative N2-fixation.
Allogamy, varietal adulteration and the breeding of okra (Abelmoschus esculentus(L.) Moench.) in Nigeria
Authors: Akoroda M. O.
Published: March 2009

Field assessments of varietal contamination from entomophilous outcrossing in okra revealed that the plant characters employed in such assessments influenced the estimate of contamination expressed as percentage of offtypes. In Nigeria, complex cropping systems, land use patterns and the abundance of insects associated with okra flowers make the effective isolation of seed crops difficult. Also, the largely subsistence production where annual seed purchase is infrequent, and consumers' acceptance of variable and ungraded edible okra fruits, imply that breeding for uniform or pure varieties may not be appropriate. Consequently, a composite bulk variety is proposed for growing or seed multiplication in areas where edible fruit production is envisaged. In this way, the difficulty of pure seed production or unwanted adulteration of varieties will not pose problems to breeders or farmers.
Zinc pools and their availability to maize-wheat rotation
Authors: Brar S. P. S. , Singh B. , Deol Y. S.
Published: March 2009

In a long-term experiment with maize-wheat rotation, no response to zinc application was observed, even after 13 years of cropping though the status of zinc had decreased to a deficient level (0.35 mg/kg; DTPA). A study was, therefore, planned to find the reasons for lack of response, and the zinc fractions in the soil were analysed to assess their contribution to plant growth. All the zinc fractions other than organic zinc decreased as a result of continuous cropping without zinc application. Depletion was from the 0-30 cm layer and mainly from acid-soluble and weakly adsorbed Zn fractions. Applied zinc remained mainly in the 0-30 cm layer as acid soluble and weakly adsorbed Zn pools. All the fractions were strongly related to each other. The acid-soluble zinc fraction contributed 54 % to zinc uptake by the crops. Thus release of zinc from this pool was perhaps the main reason for lack of response to zinc.
Efficiency of the utilization of the energy of food in laying hens
Authors: Burlacu Gh. , Baltac Margareta
Published: March 2009

The efficiency of utilization of the energy of food in White Leghorn laying hens for egg production was measured. A ration with a gross energy of 4469 kcal/kg dry matter and 19·4% crude protein had a metabolizable energy of 80·1±1·7% of the gross energy, and 78·5±5·3% of the metabolizable energy was present as net energy.

The maintenance requirement of metabolizable energy of White Leghorn hens weighing 1·723±48·5 kg and a production of 19·3±0–49 eggs per month was 125·8 kcal/kg0·75/24 hr.

The energy cost per g of protein and fat synthesized by laying White Leghorn hens was estimated to be 7·20 and 12·13 kcal metabolizable energy respectively.
Total serum protein and immunoglobulin concentrations in Scottish Blackface and Merino lambs at birth and during the first two days of suckling
Authors: Halliday R.
Published: March 2009

Merino lambs had higher serum protein concentrations at birth than Blackface lambs. In both breeds single lambs had higher concentrations than twins. The maximum mean immunoglobulin concentrations in Merino singles, Blackface singles and Blackface twins were 2·50±0·12, 2·50±0·19 and l·96±0·15 g/100 ml serum respectively, and were recorded 18 or 21 h after birth.
Inheritance of resistance to bacterial blight of cotton: I. Allen (Gossypium hirsutum) derivatives
Authors: Innes N. L.
Published: March 2009

In a replicated trial the high resistance to bacterial blight of the Allen derivatives Reba W296 and Albar strains was confirmed. Only one major gene, Lagière's B9, was detected in Reba W 296. The very high resistance of this variety is due to B9 fortified by genes of small effect.

The key to resistance in Albar derivatives is the major gene B2: the presence of B3 awaits confirmation. It was found that Albar 49, maintained in Uganda, had deteriorated in resistance to leaf infection in the Sudan. Possible reasons for this change are discussed. All Albar derivatives selected in East Africa for stem and boll resistance were found to be variable for leaf resistance under Sudan conditions.
Effect of the apetalous flower character on radiation distribution in the crop canopy, yield and its components in oilseed rape (Brassica napus)
Authors: Rao M. S. S. , Mendham N. J. , Buzza G. C.
Published: March 2009

A Brassica napus line that produces flowers with virtually no petals (Apetalous) was compared for its physiological significance with Marnoo, a related cultivar bearing conventional yellow petals. Experiments between 1984 and 1987 used different growth regulators, plant population densities and irrigation treatments. Apetalous allowed 30 % more short-wave radiation to reach the base of the inflorescence, and reflected only half as much radiation as Marnoo at peak flowering. This allowed leaves to persist and remain active for longer. Apetalous then consistently retained more seeds/pod, each of greater mean weight, at all heights within the crop canopy, resulting in substantially greater yields than Marnoo in most instances. At the highest population density, it retained productive secondary branches, whereas Marnoo had none. Irrigation after flowering increased the yields of both lines by allowing more seeds/pod to be retained, particularly at lower heights in the canopy. In Apetalous, however, even without irrigation, yields remained high. Apetalous does have larger flower parts, other than petals, which could contribute to the larger pods and seeds. This, combined with lower plant populations than Marnoo in some experiments, could have explained some of the effects seen, but the characteristic is worthy of further study in a range of genetic backgrounds and environments.
Effects of sodium hydroxide and of energy and protein supplements on the voluntary intake and digestibility of barley, oat and wheat straw by cattle
Authors: Ng'ambi J. W. W. , Campling R. C.
Published: March 2009

Three change-over experiments with yearling cattle examined the effects on voluntary intake and digestibility of treating barley, oat and wheat straws with NaOH. Increases in intake due to the NaOH treatment were: with barley straw 31 %, oat straw 9% and with wheat straw 1 %, and the corresponding improvements in digestibility were 36, 13 and 24%. A further three experimentswith yearling heifers and steers measured the effects of supplements on the responsein feeding value to NaOH treatment of wheat straw. Increasing the daily supplement of rolled barley from 10 to 3·4 kg led to a decrease in voluntary intake of treated straw from 4·6 to 3·6 kg organic matter (OM), while including urea, to increase the concentrationof nitrogenin a beet pulp supplement from 19 to 24 gN/kg dry matter (DM), gave an increasein intakeof straw from 3·4 to 4·8 kg OM. Providing more than c. 15 gN/kg dietary DM did not lead to a significant increase in voluntary intake or digestibility. In a further experiment, isonitrogenous supplements of rolled barley and soyabean meal, or rolled barley and fishmeal, led to similar intakes and digestibilities of treatedstraw. The variation in response to NaOH treatment is discussed.
Environmental and managerial factors affecting the growth of Friesian heifers from six months of age to calving
Authors: Ridler B. , Broster W. H.
Published: March 2009

The growth of 120 Friesian heifers born into one herd over a period of 12 years was studied for the period from 6 months of age to calving at about 30–35 months of age. Live weights were recorded weekly and rates of live-weight gain were calculated for each 3-month period for each animal. Δt 6, 12, 18, and 24 months of age the heifers weighed 360, 590, 800 and 950 lb. The coefficients of variation of live weight did not vary with age and averaged ±10·0%. Coefficients of variation of live-weight gain increased from ± 20% at 6–9 months of age to ±60% at 24–27 months of age. Growth rate declined by 0·02 lb/day from 12 months to 30 months of age for animals under constant managerial conditions. Heifers wintered indoors grew faster than those wintered outdoors. The growth of younger animals was decreased more by outdoor wintering (a reduction of 0·6 lb/day at 15 months) than was the growth rate of older animals (a reduction of 0·3 lb/day at 21 months of age). When live-weight gain was low in winter there was marked compensatory growth at grass the following summer. Pregnant heifers grew 0·1 lb/day faster in early pregnancy and 0·6 lb/day faster in the last 4 months of pregnancy than did barren heifers.

There was no appreciable difference between the live-weight gain of spring- and autumn-born heifers. With an autumn calving policy spring-born heifers were served and conceived 135 days earlier and weighed 106 lb less at calving than did autumn-born heifers. There was little difference in the milk yield of the two groups in 305 days of the first lactation.

The regression equation of live weight (lb) on age (months) to 3rd calving was W = 1449 – 2027 e-0·042t. It was concluded that in the interests of economic rearing the dairy farmer could with advantage exercise greater control of the relationship between nutrition and growth during high cost winter periods and low cost summer periods.
The application of an improved artificial rumen technique to the study of the effects of non-protein nitrogen on fermentation and nitrogen distribution in the rumen
Authors: Griffiths T. W.
Published: March 2009

An artificial rumen technique which simulated in vivo conditions was applied to the study of the effects of non-protein nitrogen on fermentation and nitrogen distribution in the rumen. Using this technique it was possible to reproduce in vitro a series of biochemical and other effects on fermentation that had been produced in vivo by the addition of various sources and levels of non-protein nitrogen to the rumen. It was shown that with a basal diet of cellulose, protein was synthesized from urea both in the presence and absence of starch over a period of 24 h and a typical rumen fermentation pattern was maintained.
Nutritional evaluation of kale (Brassica oleracea) diets:2. Copper deficiency, thyroid function, and selenium status in young cattle and sheep fed kale for prolonged periods
Authors: Barry T. N. , Reid T. C. , Millar K. R. , Sadler W. A.
Published: March 2009

Animals fed sole diets of kale (Brassica oleracea) were compared with animals fed ryegrass-clover pasture grown on the same soil type in two experiments. In Expt 1 young cattle grazed the two forages for 24 weeks, with supplementary copper and iodine being administered by injection. In Expt 2 young sheep were individually fed the two forages indoors at equalD.m.intake.

Animals grazing kale in Expt 1 showed the characteristic symptoms of haemolytio anaemia from ruminal fermentation ofS-methyl cysteine sulphoxide (SMCO) (Smith, 1974). This was most severe over the first 6 weeks, during which live-weight gains were very low (250 g/day). In the absence of copper supplementation animals grazing kale showed symptoms of copper deficiency. This was characterized by live-weight gain remaining low throughout the experiment (mean 280 g/day), rapid depletion of liver copper reserves, progressive reductions in serum copper concentration, reductions in erythrocyte copper and reduced glutathione (GSH) concentrations and a massive hepatic accumulation of iron. Copper deficiency only slightly lowered heart muscle copper concentration in kale-fed cattle, and this was counteracted byheart hypertrophy. The major effects of copper deficiency in kale-fed cattle were in erythrocytes, and a metabolic diagram is presented showing these effects to be biochemically similar to those produced by ruminal fermentation of SMCO.

Copper supplementation of animals grazing kale increased live-weight gain (mean 425 g/day), reduced Heinz body formation, allowed the animals to recover gradually from the haemolytic anaemia and prevented other symptoms of copper deficiency. In contrast, animals grazing ryegrass-clover pasture showed only a very mild depletion of copper, there being no response in live-weight gain to copper supplementation.

Activity of the enzyme glutathione peroxidase (GSH-Px) in whole blood was dependent upon blood selenium concentration in cattle fed both diets. In cattle fed on kale, bub not on pasture, reductions in erythrocyte GSH due to ruminal fermentation of SMCO and to copper deficiency were also associated with depressed blood selenium status.

Glucosinolates were present in the kale (11μM/g D.M.) but absent from the pasture diet. Despite this, neither T4production from the thyroid gland nor the conversion of T4to T3appeared to be impaired by kale feeding in either Expt 1 or Expt 2. In Expt 1 serum T3concentration was better relatedto live-weight gain than was serum T4concentration, in accord with T3being the active form of the thyroid hormone.

It is concluded that supplementation with copper but not iodine is essential where growing cattle are fed sole diets of kale for periods in excess of 12 weeks
Nitrogen metabolism in indigenous Malawi goats
Authors: Reynolds L.
Published: March 2009

Four mature castrate Malawi goats, mean live weight 29·66 kg, were offered diets of poor quality Rhodes grass hay, or hay plus a concentrate comprising either maize bran or maize bran-cotton seed cake mixed in varying proportions, so that N intake varied from 4·76 to 20·81 g/day in a series of four metabolism trials.

By extrapolation metabolic faecal N loss was estimated to be 9·94 g/kg faecal D.M. and that of endogenous urinary N to be 0·121 g/kg W0·75. The daily maintenance requirement for nitrogen was shown by a factorial method to be 0·682 gN/kg W0·75, and by use of regression equations to be 0·688 g N/kg W0·75 or 0·314 g apparent digestible N/kg W0·75. The mean daily requirement was 8·8 g N, with a mean apparent digestibility of N of 43·4%, and a true digestibility of 80·0%.
Effects of infusing the rumen with acetic acid and nitrogenous constituents in maize silage extracts on food intake, ruminal osmolality and blood acid–base balance in sheep
Authors: Phillip L. E. , Buchanan-Smith J. G. , Grovum W. L.
Published: March 2009

Four experiments were conducted to determine whether the products of fermentation in maize silage could limit food intake by lambs. In all experiments the lambs were fed ad libitum adietoi dried and pelleted lucerne, but were deprived of food for 4 h on the morning of intraruminal infusion. The infusions were made according to latin-square designs and commenced after 1 h of food deprivation. In Expt 1, the infusion of 3·5 I acetic acid solutions to provide 15, 30 and 60 g acetic acid had no effect (P > 0·05) on cumulative food intake compared with water. In Expt 2 infusion of three maize silage extracts differing in their composition of nitrogenous constituents suppressed (P < 0·05) food intake relative to acetic acid alone, but there were no significant (P < 0·05) differences among the extracts. When 2·71 of an extract from a low dry matter (D.M.) maize silage were infused in Expt 3 cumulative food intake was significantly (P > 0·05) decreased compared with acetic acid, but ruminal osmolality was increased to 430 mosmol/kg and ruminal pH declined to less than 5·5. In Expt 4, 1·5 1 of the low D.M. maize silage extract, an amount actually consumed by lambs during 4 h, decreased voluntary intake by 25% compared with the control but the effect was not statistically significant. Estimates of ruminal osmolality and pH ranged between 250 and 360 mosmol/kg and between 68 and 6·2 respectively. Measures of acid-base status were not affected (P < 0·05) by the infusion of acetic acid or maize silage extract. Whether specific soluble constituents of maize silage fermentation could limit food intake by ruminants was not proven.
Relationship between the blood composition of Friesian (Holstein) bulls and their improved contemporary comparisons for production traits
Authors: Rowlands G. J. , Bunch Kathryn J. , Brookes P. A. , Manston R.
Published: March 2009

Blood samples were taken from 428 Friesian (Holstein) bulls on three occasions, on average at approximately 3-monthly intervals, between 3 and 15 months of age, and also from 214 of them on three occasions at 6-monthly intervals when they were between 2 and 6 years of age.The average concentrations of blood glucose and haemoglobin and of serum cholesterol, urea, albumin, globulin, inorganic phosphate, Ca, Mg, Na, K and Cu were calculated for each of these periods and correlated with improved contemporary comparisons of milk yield and quality.

Repeatability estimates were similar within each of the two periods but were lower when mean concentrations calculated between 3 and 15 months of age were compared with those between 2 and 6 years. The main exceptions were cholesterol (0·52) and Cu (0·54) for which repeatability estimates were similar to those derived within the above two periods. The constituents with the next highest levels of repeatability were magnesium (0·44), globulin (0·43) and inorganic phosphate (0·39), which were approximately 30% lower than those obtained within the two periods.

Correlations between blood concentrations and improved contemporary comparisons were negligible, indicating that it is not possible to use these blood constituents to predict the milk production potential of a bull's daughters.
The use of soil solution K value for assessing the K status of soil during a rotation of crops
Authors: Sharma K. N. , Singh Bijay , Rana D. S.
Published: March 2009

In the last two decades significant progress has been made in understanding the factors and processes affecting the K requirement of crops. Simultaneously analytical techniques to study the behaviour of K in soil have been developed, on the understanding that soil controls the supply of nutrients to crop plants by adsorbing and sometimes fixing nutrients. As in solution culture, the concentration of K in the soil solution governs the uptake of K by plants. The soil matrix serves as a reservoir from which the soil solution is replenished. Monitoring K status of the soil solution under fixed crop sequences can provide a useful basis for improving fertilizer recommendations. Kconcentrations in the soil solution have, therefore, been measured on a soil in which a number of crops have been grown in fixed annual sequences in field experiments.