bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on goat nutrition Part I. Minimum protein requirement of goats for maintenance-endogenous urinary nitrogen and metabolic faecal nitrogen excretion studies
Authors: Majumdar B. N.
Published: March 2009

1. EUN and MFN excretions have been determined in goats on a N-low ration and also on a N-free ration. The values obtained were,

EUN = 0·052 g./kg. live weight and

MFN = 0·41 g./100 g. dry-matter feed intake.

2. The values so determined with the two feeding regimens, for both the EUN and MFN agreed very closely.

3. The minimum protein requirement of goats for maintenance, as calculated from the EUN value, is 0·65 lb./1000 lb. live weight.

4. The formula for calculating the utilizable protein requirement for this species is found to be P = 0·89. W0.734, and is almost identical with the one given by Mitchell.

5. The usefulness of the above formula in predicting the EUN of immature goats is discussed.
Effect of humidity and exposure to sun on the pulse rate, respiration rate, rectal temperature and haemoglobin level in different sexes of cattle and buffalo
Authors: Mullick D. N.
Published: March 2009

Observations in the shed were made for 3 years on groups of cattle and buffaloes of both sexes for pulse rate, respiration rate, rectal temperature and haemoglobin level during the summer months under low and high humid conditions.

The average figures for these physiological reactions were always less for buffaloes than for cattle under both dry and humid conditions.

Under high humidity conditions cattle cows showed a significant increase in the pulse rate and decrease in rectal temperature whereas respiration rate remained unchanged. In the buffalo cows these physiological reactions showed less change. In both the haemoglobin level was significantly lower during the rainy season.

On exposure to direct sun, the buffalo reacted very badly; the Iberia index was 88 for cattle and 61 for buffalo.

Because of the smaller variation in the physiological reactions due to increase in humidity at higher temperature in buffaloes (85–93° F.), this species may be considered a better dairy animal than cattle in humid tropical zones if they are protected from direct sun, which can be easily done by altering the time of grazing from day to night.
Cotton crop environment, growth and yield in the Sudan Gezira: II. The causes of variation in yield from year to year
Authors: Jackson J. E.
Published: March 2009

At three sites in the Sudan Gezira the variations in seed cotton yields between 1941 and 1961 were due, in the main, to variations in insect pest damage and, at one site only, to a downward trend in soil nitrogen level.

At each site seed cotton yield was predetermined by total plant top dry weight before the opening of the first cotton bolls. The cotton crop was sown in August. At Turabi in the northern Gezira and at the Gezira Research Station in the south-central Gezira, variations in plant growth up to early October had little effect on subsequent yield. The yield was determined by growth during October, November and December; the total top dry weight at the end of December was much more important than the pattern of growth by which this weight was attained. At these sites yield was much more closely dependent on the amount of leaf recorded as free from pest and disease damage than on total leaf weight. Damage due to jassid (Empoasca lybica), thrips (Caliothripsspp.) and leaf curl accounted for 69% of the year to year yield variation at Turabi. Damage due to jassid and thrips accounted for 56% of the year-to-year variation at the Gezira Research Station.

Severe pest damage was associated with low July plus August rains and high temperatures during the growing season but was not found to be dependent on leaf nitrogen levels.

At Hag Abdulla in the southern Gezira, there was a general downward trend in yields over the years as well as variation from year to year consequent on variations in thrips damage. The downward trend inyields was associated with a trend to lower soil nitrate and plant nitrogen levels which resulted in anearlier cessation of leaf growth in recent years than hitherto.

Variation in the level of pest attack accounted for 61% of the year-to-year variation in nitrogen response at Turabi, while at Hag Abdulla the response to nitrogen was determined by the deleterious effect of thrips and by a trend to increasing response as natural soil nitrate levels declined.

Gezira commercial crop yields were closely correlated with those of the appropriate experimental plots for the years considered (r= 0·859 for the S-type crop, 0·736 for the L-type crop) inspite of some differences in cultural practice. This suggests that the major causes of variation were the same in both cases and that adequate protection against insect pests should do much to prevent the recurrence of seasons of extremely low yield with their serious economic consequences.
Effect of environment on competitive ability of two natural populations of Dactylis glomerata L.
Authors: Eagles C. F. , Williams D. H.
Published: March 2009

The competitive ability of two natural populations of Dactylis glomerata, one from Norway and the other from Portugal, was investigated by growing them in monoculture and together in a mixed sward under different temperature and light regimes. At 7 °C and 8 h photoperiod, the performance of the prostrate Norwegian population grown in mixture with the erect Portuguese population was suppressed as compared with its performance in monoculture. However, at 30 °C and 16 h photoperiod, when the growth habits of these two populations were reversed in comparison to those at 7 °C, the dry weight per plant of the erect Norwegian population was significantly greater in the mixed sward than in monoculture. The dry weight per plant of the Portuguese population did not differ significantly in the two types of sward at either temperature. The results are discussed in relation to competition for light.
Effects of different protein contents in the rations of growing-fattening pigs
Authors: Braude R. , Townsend M. Jill , Harrington G. , Rowell J. G.
Published: March 2009

1. A co-ordinated trial has been carried out at eighteen centres to study the effects of feeding various quantities of high-protein supplement to growing-fattening pigs. In treatment 1, 10% white fish meal was included from weaning to 150 lb. live weight and 3% soya-bean meal was included from 150 lb. live weight to slaughter (approximately 210 lb.). Treatment 2 was the same as treatment 1 except that only 7% white fish meal was included during the first stage. Treatment 3 was the same as treatment 2 except that the rations were changed at 1001b. live weight instead of 1501b. Treatment 4 was the same as treatment 3 except that highprotein supplement was omitted altogether after 1501b. live weight; thus there were three rations involved in treatment 4—7% white fish meal from weaning to 100 lb. live weight, 3% soya-bean meal from 100 lb. to 150 lb. and no high-protein supplement thereafter.

2. Growth rate and feed conversion both differed significantly between treatments. Pigs on treatment 1 grew 5·0% faster than those on treatment 4; the average growth rate for treatments 2 and 3, the difference between which was negligible, was 3·3% higher than for treatment 4. Feed conversion for treatment 1 was 5·4% better than for treatment 4 and the average for treatments 2 and 3 was 3·8% better than for treatment 4.

3. Treatment differences were not significant for killing-out percentage, length, quality of fat, proportions of gammon, middle and fore-end of the cured side, thickness of streak, size of eye muscle and amount of fat over it. Some of the fat measurements differed significantly between treatments; differences in fat thickness at the shoulder, middle and rump between treatments 1, 2 and 3 were generally small, but the lowest protein level (treatment 4) resulted in carcasses with about 2% more fat along the back than the average of treatments 1, 2 and 3. These slight differences in back-fat thickness did not result in significant differences in the percentage of pigs in the highest grades.

4. An economic appraisal of the results suggested that under the conditions prevailing at the time of the experiment treatment 3 would have resulted in the greatest profit per year, and the greatest profit per pig. This ration was relatively cheap compared with those of treatments 1 and 2 but it did not lead to a seriously impaired performance, as did that of treatment 4, the cheapest ration.
Experimental design for grazing trials
Authors: Conniffe D. , Browne D. , Walshe M. J.
Published: March 2009

Animal production in grazing experiments depends both on treatment and on stocking rate. Production at optimum stocking rate is the only valid measure of treatment effect and treatment comparisons should be based on this criterion. Since optimum stocking rates are unknown these comparisons cannot be made directly, instead they must be inferred from the results obtained with the stocking rates actually used. This requires that some form of production stocking rate relationship be postulated. This paper suggests a form for this relationship and considers its implications on experimental design and particularly on the number of stocking rates per treatment.
The growth of vining peas
Authors: Meadley J. T. , Milbourn G. M.
Published: March 2009

When incoming radiation was reduced artificially to 50% daylight during the postflowering period in peas, the rate of abscission of flowers and pods increased in the same way as when the density of planting is raised. Shading from flowering onwards reduced yield almost to the level of peas that were shaded throughout the growing season, even though peas that received full daylight until flowering had many fertile tillers and a greater reproductive potential in terms of the total number of flowers produced. Conversely, when shades were removed at flowering time the crop was able to compensate and yields approached those of peas grown entirely in full daylight, this was mainly due to a reduction in absoission losses of flowers and pods so that the majority of pods formed on the main stem contributed to final yield.

It is suggested from these results that the major source of dry matter for pea yield is the photosynthate produced during the post-flowering period rather than that translocated from roots or stems following storage during the vegetative period.
Post partum conception in lactating Awassi and East Friesian × Awassi dairy ewes
Authors: Morag M. , Eyal E.
Published: March 2009

Two attempts were made to increase the number of lamb crops in intensively managed dairy sheep flocks. Rams were introduced into the flocks for the first 100 days after lambing. The ewes were milked twice daily from parturition. In the first flock of 188 ewes, the lambs were weaned at birth. Half the ewes received a course of progesterone and PMS in the third week post partum. 49% of the treated ewes conceived at average of 49 days post partum, and 59% of the non-treated ewes at an average of 53 days post partum. The hormone treatment reduced milk yield by 17% in the ewes which conceived and by 26% in those which did not conceive. Milk yield was 7% lower in those ewes which conceived a second time. Yield in the subsequent lactation was very low. In the second flock, the lambs of 83 ewes were weaned 40 days after lambing. 89% of the sheep conceived at an average of 64 days after lambing. The pregnant ewes yielded 6% less milk than those ewes which did not conceive. Yield in the following lactation was satisfactory. The practical implications of the results in terms of the possibilities of future production in dairy flocks are discussed.
The nutrition of Zebu cattle Part I. Equipment for the separate collection of urine and faeces from steers
Authors: Bredon R. M. , Marshall B. , Juko C. D.
Published: March 2009

The theory of conducting trials of apparent digestibility is simple but the practical side is expensive and requires well-trained staff. In Uganda there is a very pronounced shortage of skilled technical staff and, because of this, equipment used must be as simple as possible to avoid errors of handling and analysis of herbage and faeces. The series of investigations carried out by the authors was planned to simplify the techniques and equipment used without decreasing accuracy to any significant extent. This paper deals with the simplified apparatus which was finally used.
A note on seasonal and age changes in the calcium, phosphorus and magnesium content of the blood of Scottish Blackface ewes, as influenced by calcium and phosphorus supplementation
Authors: Gunn R. G.
Published: March 2009

In the course of an experiment designed to study the effects of calcium and phosphorus supplementation on the performance of Scottish Blackface hill ewes, with particular reference to the premature loss of permanent incisor teeth (Gunn, 1969), blood samples were taken from 40 ewes on ten occasions per year over a 4-year period. These were drawn equally from a control and three treatment groups. The control group followed the existing pattern of ewe management on the farm in question by utilizing improved pastures in the spring and early summer, and the treatment groups were a calcium dosed group (12 g calcium carbonate) and a phosphorus dosed group (13 g monosodium phosphate), both of which received the same management, and an undosed group run permanently on the hill. Details of the management and feeding are given in a previous paper (Gunn, 1969). It is sufficient to say here that mineral dosing took place three times per week between mid-February and the end of May and no minerals except salt were added to the concentrated ration fed to all groups at the rate of 10 oz (283 g)/head/day from mid-February to early May. Lambing commenced at about the end of the first week in April.
Total protein and immunoglobulin concentrations in sera from 2-day-old Finnish Landrace × Dorset Horn lambs
Authors: Halliday R.
Published: March 2009

Immunoglobulin concentrations in 2-day-old Finnish Landrace × Dorset Horn lambs were remarkably high and uniform and were unrelated to litter size. The mean concentrations in singles, twins, triplets and quadruplets were 2.95 ± 0.215, 2.95 ± 0.099, 2.94 ± 0.105 and 3.03 ± 0.142 g/100 ml respectively.
Some observations on the high level copper supplementation of pig rations
Authors: Fagan V. J. , Iles R. D. , Slowitsky Z. , Brocksopp R. E.
Published: March 2009

1. Ten experiments are reported in which the effect of high-level copper supplementation of pig rations on growth rate and food conversion was observed. In three of the experiments the study included observations on carcass quality.

2. In nine of the ten experiments a positive increase in the growth rate of the pigs receiving copper was recorded but the magnitude of this increase was markedly variable.
Environmental and genetic effects upon reproductive growth in tall fescue (Festuca arundinaceaSchreb.)
Authors: Bean E. W.
Published: March 2009

The environmental and genetic control of reproductive growth was studied in S. 170 a variety ofFestuca arundinaceaSchreb. The variety had induction requirements for short days and low temperatures before inflorescence production could occur, but some genotypes became induced with only short-day treatments. Low temperatures and short days in controlled environment rooms were less effective in bringing about induction than winter conditions in an unheated glasshouse. Only non-additive genetic effects could be shown to be significant in the control of induction requirements. Field studies showed that all inflorescence characters were subject to genetic and genetic x environmental control, and they also indicated that seed weight per inflorescence and seed fertility were most likely to show a response to selection. Diallel analysis under glasshouse conditions showed that the seed fertility and 1000 seed weight of the parental crosses were subject to maternal control, but these effects were not detectable in the next generation. Genetic control of seed fertility and 1000 seed weight in the diallel progeny was mainly additive.
Subjective assessment of body fat in live sheep
Authors: Russel A. J. F. , Doney J. M. , Gunn R. G.
Published: March 2009

Subjectively assessed body condition scores, determined on the live animal, were related to the percentages of chemical fat in the fleece-free empty bodies of 30 adult Scottish Blackface ewes. The results show that body condition scores can provide an acceptable and useful estimate of the proportion of fat in the live animal, and that the level of prediction is superior to that afforded by live weight.
An analysis of the growth of inbred progeny ofLolium
Authors: Bean E. W. , Yok-Hwa Chen
Published: March 2009

The growth of the progeny from self-pollination was studied in seven cultivars ofLolium perenneand five cultivars ofLolium multiflorum. All cultivarsotLolium perenneshowed a reduction in the dry weight of the selfed progeny after one generation of inbreeding, although only four of these attained statistical significance. By contrast the reduction inLolium multiflorumwas less marked with only one cultivar showing a significant reduction on inbreeding. An analysis of the growth of two of theLolium perennecultivars which showed reduced vigour in progeny from self-pollination suggested that a lower germination rate and a slower development of leaves in the seedling were two factors which resulted in reduced weights in inbred progeny. The possible effect of the environment in which the inbreds were produced on seedling performance is discussed.
The effect of level of intake and free fatty acid content on the metabolizable energy value and net absorption of tallow by the laying hen
Authors: Shannon D. W. F.
Published: March 2009

The metabolizable energy (ME) values and net absorption of tallows containing 20, 40, 60, 80 or 98% free fatty acids were determined using mature laying hens. By restricting food intake, the intake of the tallows was controlled to 3, 5, 10 or 20 g per bird d. The tallows were added to a diet of known ME content and the ME's of the tallows were calculated from the data collected from 6- or 7-day energy balances.

ME and net absorption values of the tallows were significantly (P < 0·001) lowered when the level of intake was increased from 3 to 20 g/bird d. The values were also significantly (P < 0·001) lowered when the free fatty acid content was increased from 20 to 98%. The effects of free fatty acid level (F) and level of intake (L) on the ME and net absorption values were considered in terms of curved surfaces represented by equations embracing the factors and their product. The equations obtained were:

ME(kcal/g) = 8·745 – 0·004F – 0–361 log10L–0·011 F log10L,

Net absorption (%) = 95·82 + 0·02F – 4·65 log10L – 0.13F log10L.
The analysis and prediction of some two factor interactions in grass breeding
Authors: Wright A. J.
Published: March 2009

A method of analysis of two factor experiments is given. This involves a development of the regression analysis used by Finlay & Wilkinson (1963) and others, and allows for the regression of interaction components onto both main effects. The usefulness of the single joint regression parameter for prediction is outlined.

The applicability of the analysis to three situations commonly found in grass breeding is illustrated by means of examples. It is concluded that the model may frequently describe variation due to genotype-environment interactions, and among diallel arrangements of binary mixtures of genotypes, but is likely to be of little utility for genetic diallel or other mating schemes unless the genes have a strongly correlated distribution among the parent plants.
Changes associated with pregnancy and lactation in some extra–reproductive organs of the ewe
Authors: Fell B. F. , Campbell Rosa M. , Mackie W. S. , Weekes T. E. C.
Published: March 2009

The food intake, the apparent digestibilities of dry matter, and of nitrogen were measured in housed Blackface ewes during late pregnancy, lactation, and after the lambs were weaned. The ewes were slaughtered serially together with non-breeding controls, and the liver, ruminal mucosa, intestines, CNS and carcass were weighed. In association with differing reproductive status marked changes occurred in the content of dry matter and protein in the alimentary organs, but not in the CNS, and the mean weight of DNA in the CNS for all the animals was 130 ± 20 (S.D.) mg.

All of the alimentary organs became hypertrophied during lactation, and regressed after weaning. Maximum values for the liver and ruminal mucosa occurred in the sixth week of lactation, and were maintained until weaning. The small intestine reached maximum weight after 4 weeks of lactation.
Effects of pregnancy and lactation on the activities of some gluconeogenic and urea-cycle enzymes in sheep liver
Authors: Mackie W. S. , Campbell Rosa M.
Published: March 2009

The effect of reproductive state on the activity in sheep liver of the gluconeogenic enzymes glucose-6-phosphatase and fructose-1,6-diphosphatase, and of the urea cycle enzymes arginase and the arginine synthetase system, was investigated. The sheep were Blackface ewes that were killed during pregnancy, lactation and after the lambs were weaned, together with non-breeding controls.

The total activities in the liver of glucose-6-phosphatase, and of arginase, fell during pregnancy and rose during lactation in proportion to liver hypertrophy, reaching maximum values late in lactation.

In breeding ewes total hepatic fructose-l,6-diphosphatase activity differed little from that in the controls except in the period 14 days before to 13 days after parturition, during which the activity was 10 times higher than at other times. The arginine synthetase system declined in activity during late pregnancy. There were 2 peaks in activity after parturition, one at 30 dayspost partumand one at 30 days after the lambs were weaned. The peaks possibly were associated with periods of resorption of maternal proteins.
A source of error in the estimation of the organic matter content of samples containing calcium carbonate
Authors: Hovell F. D. DeB. , Ørskov E. R.
Published: March 2009

The conventional method for the determination of the organic matter content of diets and faeces is by ashing the sample at 550 °C (A.O.A.C, 1965)

Organic matter (O.M.) = dry matter (D.M.)–ash.

If the sample contains calcium carbonate, then some of this carbonate will be converted to oxide (Vogel, 1951) and the weight of carbon dioxide evolved will be calculated as organic matter. The amount of carbonate converted will be dependent upon the temperature at which the sample is ashed and the duration of the ashing process. We have found (Ørskov, Hovell & Allen, 1966; Hovell & Greenhalgh, 1972) that when calcium salts of volatile fatty acids are included in diets given to sheep, most of the calcium is excreted in the faeces as carbonate, and since apparent digestibility is the difference between the amounts of nutrient ingested and excreted, the estimation of the apparent digestibility of organic matter will be in error if no correction is made for the high calcium carbonate content of the faeces. For example, a diet which contained 9·2% of calcium acetate had a true organic matterapparent digestibility of 86·8%. Had no correction been made this would have been estimated as 84·9%.
Prediction of the body composition of live cattle
Authors: Little D. A. , Morris J. G.
Published: March 2009

Two methods of determining body composition in live cattle have been compared with the composition of the cattle as determined by chemical analysis. Total body water (TBW) was estimated from tritiated water (TOH) dilution, and circulating redcell volume (RCV) estimated from measurements of plasma volume and haematocrit. TBW was very closely related to fat-free weight and fat weight as a percentage of live weight (LW) in eight cattle ranging from 3 to 34% fat. TOH space was more precise than RCV in the estimation of the various chemical fractions of the live animal.

TOH injected intravenously equilibrated with ruminal water in 8–10 h; one could be confident that equilibration had occurred 10 h after injection, and equilibration time was not affected by previous restriction of feed and water. The mean biological half life of TOH was 4·2 ± 0·4 days. Equations are presented for the practical determination of the various compartments.
The effect of interval between harvests and nitrogen application on the numbers and weights of tillers and leaves in four ryegrass varieties
Authors: Wilman D. , Koocheki A. , Lwoga A. B. , Droushiotis D. , Shim J. S.
Published: March 2009

The effect of six intervals between harvests and three levels of N application on the number of tillers was studied in four ryegrass (Lolium) varieties in the first harvest year and in two varieties in the second and part of the third harvest years in a field experiment. Weight/tiller was recorded in the first 2 years and weight/green leaf and number of green leaves harvested were recorded in the first year.

There was a large negative interaction between level of N and interval between harvests in respect of number of tillers, the number being increased by N with short intervals and tending to be reduced by N with long intervals. The interaction was larger in the second and third years than in the first. The negative interaction in respect of number of tillers and number of green leaves harvested was associated with a reduction in the percentage increase in yields of dry matter, digestible organic matter and N due to the application of N as the interval was increased. It is suggested that one should in general avoid a combination of high N and long intervals between harvests with present varieties of perennial ryegrass.

The effects of interval between harvests, N application, variety and time of year on number of tillers and weight/tiller are discussed in relation to their effects on yield to show how tiller information can contribute to a better understanding of the ways in which yields are achieved. Rather low yields in the late summer and early autumn of the second harvest year were in many instances attributable to a rather low number of tillers rather than to low weight/tiller.

There was a considerable increase in number of tillers between the end of one growing season and the early part of the next, suggesting that the period in which this increase is achieved may be an important one in relation to the continued vigour of the sown species.

A reduction in annual yield of green leaf with extension of interval from 6 to 10 weeks with N applied resulted from a reduction in the number of green leaves harvested/harvest and in the number of harvests, which outweighed an increase in number of green leaves harvested/tiller and in weight/green leaf. Increasing the level of N with intervals of 3–6 weeks increased the number of tillers, the number of green leaves harvested per tiller and per unit area of ground and weight/green leaf and hence consistently increased green leaf yield.
Yield potential in a dwarf spring wheat and response to crop thinning
Authors: Fischer R. A. , Laing D. R.
Published: March 2009

Experiments with wheat describing the effects of crop thinning on grain yield and its components are presented. These were carried out over 5 years in northwest Mexico, using a high-yielding dwarf spring-wheat variety (Triticum aestivumcv. ‘Yecora 70’) grown under irrigation and high fertility. It was shown that thinning largely relieved competition for light, thus increasing photosynthate levels in the plants remaining after thinning. The objective was to evaluate this simple technique as a guide to understanding when grain yield and its components were determined and, in particular, the extent to which post-anthesis photosynthate supply limited yield.

There were major responses in grain yield with thinning between about 50 and 100 days after seeding, and in number of spikes and of grains with thinning between 50 and 90 days (50% anthesis was reached at 87 days). Number of spikelets per spike showed small responses to early thinning (before 50 days). Number of grains/spikelet and kernel weight snowed positive responses to thinning between 65 and 90 days, and 90 and 115 days, respectively. These results agreed with adjacent shading and CO2fertilization studies but, because of certain difficulties in interpretation of responses, pre-anthesis thinning was not considered a very useful technique.

Anthesis thinning was carried out on 21 separate crops: the kernel weight increase relative to the unthinned control ranged from 6 to 41%, averaging 20%. Anthesis thinning led to increases in stem weight during the first half of the grain filling period, followed by increases in grain growth rate in the latter half. The increase in final kernel weight was greater with higher temperature and lower radiation during grain filling; these variables explained 64% of the variation in kernel weight response. It is suggested that the kernel weight response does indicate the degree of photosynthate limitation during grain filling, showing reasonable agreement with adjacent shading and CO2fertilization studies. It was concluded that anthesis thinning, because of its relative simplicity, is a useful technique. Implications for yield improvement in Yecora of the results provided by this technique are discussed.
A comparison of the effect of straw incorporation and CO2 enrichment on the growth, nitrogen fixation and yield of soya beans
Authors: Shivashankar K. , Vlassak K. , Livens J.
Published: March 2009

In a glasshouse pot culture experiment, the effect of adding straw at 3 and 6 t/ha with and without CO2 enrichment treatments at 1000 mg/1 from flowering to the pod-filling stage in open top chambers was evaluated on the growth and yield of soya beans in relation to nitrogen fixation. N2-ase activity of the soya-bean root nodules as determined by the acetylene reduction technique indicated that (1) straw on average gave significantly 34 and 43% higher N2-ase activity at 3 and 6 t/ha respectively than the controls; (2) CO2 treatments on average increased the activity by 34% compared with the no CO2 treatments; and (3) the mean N2-ase activity nearly doubled from 9·7 μg/h/plant in the control to 18·7 and 19·7 μg/h/plant with straw incorporation in conjunction with CO2 enrichment. High correlations were observed between weight of nodules and dry weight of leaves, between dry weight of nodules and grain yield and between dry weight of leaves and grain yield. Incorporation of straw was found to be beneficial in increasing CO2 content of soil air and in improving the growth and development of the plants. This study lends support to a hypothesis that straw can be considered to provide a partial substitute for the expensive CO2 enrichment treatment for improving N2(C2H2) fixation capacity and thereby the general growth and yield of crops.
Effect of the amount and form of roughage in the diet on digestibility of whole maize grain in cows and steers
Authors: Nordin M. , Campling R. C.
Published: March 2009

Four experiments investigated some of the factors affecting the digestion of whole maize grain in non-lactating cows and yearling steers. With steers, but not cows, maize in diets containing small amounts of hay (14%) and large amounts of whole grain were better digested than those with 37 or 48% hay. The higher digestibility of maize in steers was associated with a greater time spent ruminating per kg feed and a longer retention time of maize in the gut than in cows. Replacing long roughage with ground and pelleted roughage in diets for steers improved the digestion of whole maize but not as well as reducing the hay to 14% of the diet. Finely grinding the maize produced a large increase in digestibility of the feed in cows and steers and both digested it to the same extent. It was concluded that the motility of the reticulo-rumen during eating and ruminating largely determines the extent of the digestion of whole maize grain.
The deposition of sulphur in dust in northern Nigeria
Authors: Bromfield A. R.
Published: March 2009

The deposition of dust and the sulphur it contained were measured at 10 sites for three dry seasons in northern Nigeria. Amounts of dust deposited varied between seasons and sites depending on the concentration of dust in the air and the duration of dust storms. Deposits ranged from 226 to 52 kg/ha (mean value 146) measured in a south-westerly direction across the area studied; the S deposition ranged from 0·099 to 0·429 kg/ha (mean value 0·226). The most south-westerly sites received plant ash from clearing fires which increased the S deposited, but not the net gain of S to the whole area. The agricultural significance of the results is briefly discussed and other sources of atmospheric-S are considered.
The frequency of natural cross-fertilization in a composite cross of barley grown in Scotland
Authors: Giles R. J. , McConnell Gillian , Fyfe J. L.
Published: March 2009

The frequency of natural crossing in 1972 was estimated, in two subsets of a composite cross grown inF6in Nairn and in Fife, as 2·61±0·25% and 4·59±0·35% respectively. The estimated inbreeding coefficients of the parental generations were less than would be expected if all types of pollination were equally fertile and gave equally fertile offspring.
The effect of plant density, date of apical bud removal and leaf removal on the growth and yield of single-harvest Brussels sprouts (Brassica oleraceavar.gemmiferaD.C.): II. Variation in bud size
Authors: Fisher N. M.
Published: March 2009

A method is suggested for estimating the mean bud size and standard deviation of a sample of sprout buds, separated into size grades by the use of riddles. From the standard deviation a potential size fraction is estimated, being the fraction of the buds occurring in a size grade of 10 mm width if the mean bud size were located at the mid-point of the grade. This estimate of bud size uniformity was independent of date of sampling for a period of at least 4 weeks.

The potential size fraction was increased by stopping (apical bud removal) and in some cultivars an optimum stopping date was indicated. Increased plant density also increased the potential size fraction, particularly in unstopped crops. Between-plant variation in bud size was significantly greater for the hybrid Thor than the outpollinating Seven Bills but within-plant variation was the more important component of overall bud size variation and was greatly reduced by stopping and by increased plant density in unstopped crops. Mean bud size at any harvest date was increased by early stopping and lower plant density.

It is concluded that the date of stopping should be chosen to minimize bud size variation and the plant density varied to spread maturity.
Effect of flower or pod removal on the performance of soya beans (Glycine max. L.)
Authors: Tayo T. O.
Published: March 2009

All flowers were removed daily on soya-bean plants (cv. Hampton) for 1, 2, or 3 weeks and all pods developed on the plant were removed after 1, 2 or 3 weeks of pod development, in two field trials, in order to evaluate the effects of removing flowers or pods on the growth, development and yield of the cultivar. Removal of flowers or pods led to less dry-matter accumulation, longer leaf area duration and delayed maturity of the plants and these became more pronounced with the severity of the removal.

Number of mature pods per plant, number of seeds per plant, pod yield per plant and seed yield both per plant and per hectare, were significantly reduced when flowers were removed for 1 week or pods removed after 2 or 3 weeks of development in the early season crop. Yield was reduced by 27%, 35% and 40% respectively both per plant and per hectare. In the late season crop, removing flowers for 3 weeks or removing pods after 3 weeks of development led to significant reduction in number of mature pods per plant, number of seeds per plant, number of seeds per pod, pod yield per plant and seed yield both per plant and per hectare. The magnitudes of yield reduction were 40% and 49% respectively.

The ability of the variety of soya bean used in this study to prevent significant reduction in seed yield by compensatory development, following flower or pod removal, depends on the severity of the removal vis-d-vis the stage of development of the plant and its vigour.
Seasonal dependence of wheat variety response to superphosphate
Authors: Jessop R. S. , Palmer B.
Published: March 2009

Two field experiments were made to examine differences in wheat variety response to applied superphosphate. In the first experiment, conducted under dry conditions, both yield and yield response to superphosphate were low; in the second experiment some semi-dwarf wheats showed a greater response than standard-height wheat varieties. The semi-dwarf wheats had a greater proportion of plant phosphorus in the reproductive sections of the plant at maturity. The semi-dwarf variety Israel M 68 also showed the greatest increase in root production following the application of superphosphate.
Evaluation of nitric phosphates differing in water solubility of their phosphorus fraction
Authors: Singh Bijay , Hundal H. S. , Sekhon G. S.
Published: March 2009

Three nitric phosphate fertilizers with 30, 60 and 70% of their phosphorus in watersoluble form were evaluated relative to superphosphate and rock phosphate on neutral to alkaline soils. The test crops were wheat, paddy and berseem. Linear grain yield and dry-matter yield responses were obtained up to 100 kg P2O5/ha for wheat and berseem, respectively. Quadratic response functions were fitted to paddy grain yield. Yields of the various crops were well related to the water solubility of the P fraction in different sources. Availability coefficient ratios were calculated for each fertilizer. These indicated that the minimum water solubility of the phosphorus fraction in nitric phosphates required for high crop yields is dependent on the nature of the crop, on soil characteristics and on the method of application which together determine the shape of the response curve. Band placement of sources with higher water solubility of their P fraction (70% or more) resulted in fertilizer efficiency similar to wholly water-soluble sources. Nitric phosphates of 30 and 50% water-solubility were inferior to water-soluble sources when applied broadcast. However, where curvilinear responses were obtained, low water-solubility sources (30 or 50% water-solubility) performed better at higher than at lower rates of application.
The effects of milk feeding on the pre- and post-weaning growth of calves, and on stomach development at weaning
Authors: Kaiser A. G.
Published: March 2009

The pre-weaning and post-weaning gain, oaroass production and stomach development of oalves fed four levels of whole milk (8%, 10%, 12% and 14% of live weight daily) was studied in two experiments. Calves had access to pasture at all times and were weaned at 12 weeks. Pre-weaning gain, weaning live weight, and carcass weight at weaning all increased as the quantity of milk increased. At the 14% level, male calves reached heavier weaning live weights and produced heavier carcasses than females. Reticulo-rumen weight, when expressed as a percentage of total stomach weight, was significantly reduced with increased milk feeding. Calves reared on the higher quantities of milk gained more slowly after weaning, this being attributed to their poorer reticulo-rumen development at weaning.
Analysing data with repeated observations on each experimental unit
Authors: Rowell J. G. , Walters D. E.
Published: March 2009

Split-plot (or split-block) analyses are commonly applied to experimental results where several successive observations of the same variable have been recorded on each experimental unit. The assumptions required for such analyses receive scant attention and it often seems unlikely that these assumptions would be satisfied in experimental situations. Five sets of results are presented to support this proposition. An alternative analytical approach is suggested in which contrasts over time are analysed; such a method is always valid, computationally simple, and readily interpretable, and may also be used to gauge the validity of the split-plot analysis.
The effect of compensatory growth in sheep on empty body weight, carcass weight and the weights of some offals
Authors: Winter W. H. , Tulloh N. M. , Murray D. M.
Published: March 2009

The effects on the body composition of Corriedale wethers of weight loss, compensatory gain and constant body weight are described. Three groups of sheep were grown from 35–63 kg by different paths. The first grew continuously (fedad libitum). The second and third groups lost 20% and 28% of body weight (restricted intake), respectively, from 48 kg and were then fedad libitumuntil they reached 63 kg. Pairs of animals were slaughtered at intervals in each group. A fourth group of sheep was maintained at 48 kg. Analyses of covariance comparing regression equations were used to determine differences in body composition between the first three groups.

The compensatory growth rates of both groups which had lost weight were 1·5–2 times those during continuous growth. These increases were associated with an increased gut content of these animals and a concomitant reduction in the proportion of empty body weight (EBW) and carcass weight (CW) in t he full body weight (FBW). Thus, the apparent dressing percentage (CW/FBW x 100) was reduced by 2% during compensatory growth. The carcass length was not reduced during weight loss and its growth in relation to the CW was not affected by treatment. Thus compensatory growth animals had longer carcasses. Similar increases in gut contents and carcass length were found for animals maintained at constant body weight.

During developmental growth the proportions of the external offals, organs and gut tissue decreased in relation to the EBW; notable exceptions were the large intestine and caul fat where the proportions remained constant and increased, respectively.

The growth of the CW, lungs, large intestine and head were not reversed during weight loss whilst the liver, heart, hide and gut tissues (except the large intestine) all lost more weight during weight loss than they had gained during the growth phase. The proportions of these latter components were increased in relation to the EBW during the ensuing compensatory growth.

In general, the composition of animals held at constant body weight was similar to that of animals experiencing compensatory growth at the same weight and age.
Heterosis and combining ability in a diallel cross of chilli (Capsicum annumL.)
Authors: Soh A. C. , Yap T. C. , Graham K. M.
Published: March 2009

In a 7×7 diallel-cross experiment utilizing parents with varying resistance to mosaic virus disease and of different horticultural types significant heterosis over the better parent was found in number of days between sowing and flowering and over the mean of the two parents in other characters. The combining ability analysis revealed that genetic control of most character variation was due to additive effects.

It is suggested that pedigree and/or backcross methods are most appropriate for improving this chilli population.
Heat tolerance of different genetic groups of sheep exposed to elevated temperature conditions
Authors: Singh M. , More T. , Rai A. K.
Published: March 2009

Indian Chokla and Malpura and their crosses with exotic Rambouillet and pure bred Rambouillet sheep were exposed to increasing temperature (20, 25, 30, 35 and 42 °C), or to 40 °C for 6 ha day for about a week, or suddenly to 40·4 or 44·2 °C to study their relative heat tolerance. Pronounced increase in the frequency of respiration under hot conditions together with increase in rectal temperature (under 44·2 °C) of Rambouillet contrasted with the physiological responses of the native breeds of sheep. Under thermal stress the Chokla and Malpura consumed more feed than the Rambouillet or the half breds. The Rambouillet × Chokla or the Rambouillet × Malpurahalf breds were apparently more heat tolerant than the Rambouillet sheep.
Evaluation of protein quality of poultry feedingstuffs. 1. Comparison of chick bioassays
Authors: Zombade S. S. , Lodhi G. N. , Ichhponani J. S.
Published: March 2009

Body-weight gain, protein efficiency ratio (PER), standardized protein efficiency ratio (Std PER) and gross protein value (GPV, GPV1and GPV2) bioassays were compared with nitrogen incorporation efficiency (NTE) for their accuracy and precision to determine protein quality of fish meal (FM), groundnut cake (GN), mustard cake (MS) and cottonseed cake (CS) for poultry. Results showed that all the bioassays were significantly (P < 0·05) correlated with NIE and were equally effective in ranking the samples of FM, GN, MS and CS according to their protein quality although body-weight gain procedure was less sensitive.
Evaluation of protein quality of poultry feedingstuffs. 3. Expeller-processed oilseed cakes
Authors: Zombade S. S. , Lodhi G. N. , Ichhponani J. S.
Published: March 2009

A study was made to evaluate the protein quality of groundnut cake (GN), mustard cake (MS) and cottonseed cake (CS) and to find a suitable laboratory test for predicting the protein quality of these cakes for chicks. Different oilseed cakes varied considerably in their crude protein, true protein and crude fibre content. The nitrogen solubility was higher in GN (87·7%) followed by MS (78·7%) and CS (60·9%). A similar trend was evident with regard to in vitro protein digestibility. The GN protein was, however, lower in available lysine (2·54%) than MS (3·97%) or CS (3·19%). The albumin, globulin, prolamin and glutelin fractions accounted for 74·1, 57·0 and 48·0% in GN, MS and CS, respectively. The nitrogen solubility, globulin content and modified relative nutritive value (RNV) correlated (P < 0·05) with gross protein value (GPV). The accuracy and precision of various regression equations for predicting the quality of protein in GN, MS and CS are discussed.
Water uptake and trans-potential in sunflower roots as influenced by ammonium ions
Authors: Ragab S. M.
Published: March 2009

The effect of ammonium ions on artificially imposed water flux and trans-root potential difference was studied in excised sunflower roots. Water movement through the root system decreased and the potential of the xylem sap became less negative with respect to the external medium as the ammonium ion concentration in the external medium increased. It is suggested that ammonium ions appeared to inhibit water uptake either wholly or partially through a general or specific blockage of root metabolism which reflected on the permeability of water through root membranes. The reduction in the trans-root potential was due to the effect of ammonium ions on the original trans-root potential of epidermal root cells. This may indicate that the site of water uptake inhibition lies within the root epidermis.
Nutritional studies with sheep fed conserved ryegrass. 2. Silage supplemented with dried grass or barley
Authors: Wernli C. G. , Wilkins R. J.
Published: March 2009

Grass silage (21.0 % D.M.) was given ad libitum to sheep together with supplements of rolled barley, dried-grass pellets or dried-grass wafers at 12 and 25 g organic matter (OM)/kg0·75.

Intake of silage was greater with supplement at 12 g/kg0·75 but total intake of OM and digestible organic matter (DOM) increased with increasing supplement. Intake of OM was higher with the pellet supplement than with other supplements. Intake of DOM, however, did not differ between the pellet and barley treatments, but was lower with wafers.

Concentrations of ammonia and total volatile fatty acids and the molar proportions of butyric and higher volatile fatty acids were higher when silage was supplemented with barley than with dried grass. Mean rumen retention times of silage and of supplement were highest in the barley-supplemented treatments. Dried-grass wafers were retained longer than dried-grass pellets. Supplement treatments did not differ significantly for eating and ruminating times, rumen fluid volume and pH, digestion rate in the rumen and nitrogen retention.

At the low supplement rate silage consumption may have been controlled by factors associated directly with the silage, whereas at the high rate intake was limited either by physical factors or by the potential energy demand of the animals.