bluuebunny/crossref_metadata_2025_split huggingface dataset:
The phosphorus cycle in pig slurry measured from 32PO4 distribution rates
Authors: Gerritse R. G. , Zugec I. 
Published: March 2009

SUMMARYThe rate of isotopic distribution of labelled phosphorus, added as H332PO4, between inorganic and organic phosphates and phosphates contained in micro-organisms was measured in pig slurry. Incorporation of 32P in all these phosphates occurred quickly in both aerated and non-aerated pig slurry. On the basis of a simplified model, turnover times for phosphorus were calculated to be of the order of 10–20 weeks for both non-aerated and aerated pig slurry.Pig slurry contains 1–2% P (of dry matter) of which 10–30% is in organic molecules and 2–3% is in micro-organisms. About 10–20% of the organic phosphates is in solution, amounting to 10–20 mg P/l. The concentration of inorganic P in solution is of the order of 10–100 mg/1 though, at low Ca/P ratios in the feed, can be as high as 1000 mg/1.Organic phosphates in solution in pig slurry are of high molecular weight and probably consist of DNA complexes with polyphosphates, Ca and (if used in the feed) Cu.It is concluded that all organic phosphates in pig slurry are of microbial origin and that the feed composition has little influence on the organic phosphate content of the
slurry.Arguments for application of the results to pig slurry in general and to wastes from
other animals are given.
Effects of two paths of live-weight change on the efficiency of feed use and on body composition of Angus steers
Authors: Foot Janet Z. , Tulloh N. M. 
Published: March 2009

SUMMARYThis paper describes the effect of two paths of weight change on the total feed consumed and on body composition at slaughter of Angus steers. The treatments were: a 15% weight loss from 330 kg live weight, at 0·5 kg/day for 100 days, followed by recovery to 330 kg on ad libitum feed intake (WL/WG group), and constant weight at 330 kg for the same length of time as corresponding paired animals in the WL/WG group took to complete their treatment (constant-weight group). There were six animals in each group and they were slaughtered when the WL/WG steers reached 330 kg. At the beginning of the experiment four animals (preliminary group) were slaughtered at 330 kg.Intakes of feed were recorded and measurements of apparent dry-matter digestibility were made at intervals. Chemical analyses were carried out on the right side of each carcass and on the other components of the body.The mean total intake of the WL/WG group was 12% less than that of the constant-weight group. The daily dry-matter intake in the constant weight group decreased from 5·9 kg to 4·4 kg during the experiment.The time taken for the WL/WG steers to regain the 50 kg weight loss varied from 30 to 68 days. Their intakes at this time and their growth rates were similar to those that they experienced when they grew to 330 kg for the first time.Apparent digestibility varied between animals but was not influenced by treatment. The constant-weight group were fatter than the WL/WG group at slaughter and had heavier carcasses, both differences being significant (P < 0·05). The difference between groups in empty body weight was not significant. Animals from the final slaughter groups had significantly heavier heads and feet and a higher ash content than the younger steers of the preliminary group. Liver weights were reduced by nutritional restriction and did not fully recover in WL/WG steers.
Morphology and genetics of two gene markers, ‘Swollen stem base’ and ‘Hastate leaf’ in cowpea, Vigna Unguiculata (L) Walp.
Authors: Ojomo O. A. 
Published: March 2009

SUMMARYTwo gene markers were observed among cowpea breeding lines in Ibadan, Nigeria. One is the swollen stem base which is due to a larger quantity of phloem parenchyma in the bottom part of the stem below the first primary leaf than in the normal stem. It is inherited as a simple dominant trait and the symbol Sw is suggested. The other is the hastate-leaf which is expressed as extremely narrow trifoliate compared with the normal. It is inherited as a simple dominant trait and the symbol Ha is suggested. Dominance may not be complete in both cases as variable expressions of the marker genes were observed in F2. The effects of the marker genes on yield and other characters are currently being investigated.
The effects of breed, breeding system and other factors on lamb mortality: 4. Factors influencing the incidence of infectious and non-infectious diseases as causes of death
Authors: Macleod N. S. M. , Wiener G. , Woolliams Carol 
Published: March 2009

SUMMARYThe incidence of various infectious and non-infectious diseases as causes of death in lambs up to 8 months of age was studied in relation to breed, inbreeding and other factors. The data from an upland grazing flock covered 6 years and involved the Scottish Blackface, Cheviot and Welsh Mountain breeds and the crosses among them.Infectious and non-infectious diseases were directly responsible for almost a quarter of the mortality and their presence contributed to many more deaths. The organisms mainly responsible were Escherichia coli, Pasteurella spp. and Fusobacterium necrophorum.The incidence of infectious diseases in general and enteritis in particular varied significantly between the breeds and was lower in the cross-breds than in the purebreds. Variation between the breeds in the incidence of non-infectious diseases was statistically significant only in respect of digestive upsets for which there was a similar ranking of breeds to that for infectious disease.Inbreeding of the lamb (25–59%) significantly increased the incidence of infectious diseases, especially respiratory diseases, but not of non-infectious diseases. There was little difference between singles and twins in susceptibility to disease. The lower the birth weight of the lamb the greater the risk, particularly of non-infectious disease.
Prediction of carcass composition from carcass conformation in cattle
Authors: Bass J. J. , Johnson D. L. , Colomer-Rocher F. , Binks G. 
Published: March 2009

SUMMARYConformation of carcasses from 98 steers from ten different sire breeds was classified according to two visual systems and two objective measurements, which were related to both commercial and dissected carcass composition of their hindquarters. The visual carcass conformation systems, unlike the objective systems, accounted for only a small percentage of the variation in some carcass traits after adjusting for the weights of the right hindquarter and of dissected fat from that hindquarter. Of the carcass conformation systems tested, the objective measurement of area appears to be the best predictor of carcass traits, with the variation in the weight of meat being reduced by 13·4% (P < 0·001) by the inclusion of area measurements. It is suggested that an objective assessment of carcass conformation might be of use in a national carcass classification or grading system.
Regrowth of perennial ryegrass as affected by simulated leaf sheaths
Authors: Davies Alison , Evans M. Eleanor , Exley Janet K. 
Published: March 2009

SUMMARYSimulating the accumulation of dead leaf sheaths in perennial ryegrass by masking the tiller bases increased leaf and sheath length and tiller weight but decreased tiller production. Exposure of previously masked tiller bases or stripping back the subtending leaf and sheath to expose the tiller bud in its axil stimulated tiller production. A photomorphogenic effect is postulated which controls the partitioning of dry matter between the growth of new leaf and sheath tissue on existing tillers, and the development of new tillers from tiller buds.
Nutrition and growth of gnotobiotic lambs
Authors: Lysons R. J. , Alexander T. J. L. , Wellstead Patricia D. 
Published: March 2009

SUMMARYSeventeen gnotobiotic lambs were reared up to 21 weeks of age on cows’ milk followed by sterile solid diets similar to diets fed to conventional lambs. Seven were given limited defined populations of rumen bacteria, seven were left uninoculated and three were dosed with rumen contents from conventional sheep (‘conventionalized’). The lambs were reared in four groups corresponding to four lambing seasons.Gnotobiotic lambs fed cows’ milk ad libitumgrew at similar rates and converted feed into live-weight gain with similar efficiency to conventional lambs. The gnotobiotic lambs irrespective of inoculation and the two conventionalized lambs in the first three groups failed to maintain growth on solid diets when milk feeding had been stopped. However, three gnotobiotic lambs in the fourth group, two of which were inoculated, continued to grow satisfactorily for at least 6 weeks on a solid diet alone, and the inoculation of defined populations of bacteria appeared to confer an advantage. The conventionalized lamb in the fourth group suffered a severe temporary setback, following which it grew well.
The value of palm kernel meal in finishing diets for pigs: 1. The effect of varying the proportion of protein contribution from blood meal and palm kernel meal on the performance and carcass quality of finishing pigs
Authors: Fetuga B. L. , Babatunde G. M. , Oyenuga V. A. 
Published: March 2009

SUMMARYForty (20 barrows and 20 gilts) Large White and Landrace pigs allocated on the basis of litter origin, sex and initial weight to four treatment groups with mean initial weights of 50 kg were individually and semi-restrictedly fed to about 93 kg one of four diets containing 18·8, 28·5, 38·2 and 46·5% palm kernel meal (PKM) and 11·3, 8·4, 5·5 and 4·6% blood meal respectively such that the ratio of protein contribution to the diet from blood and palm kernel meals were 2·7:1, 1: 1·3, 1: 1·6 and 1: 2·30 for diets 1, 2, 3 and 4 respectively. Growth performance was measured over the liveweight range of 50·93 kg at which latter weight the pigs were slaughtered for carcass evaluation. Live-weight gain and feed efficiency were highly significantly influenced by varying the levels of palm kernel meal and blood meal, the lowest level of palm kernel giving significantly the best rate and efficiency of gain. There was a tendency for carcass leanness to improve as the proportion of dietary protein supplied by palm kernel meal was increased, only the differences for lean meat percentage were however significant. Carcass cuts as percentage of total carcass did not appear to be influenced by the level of palm kernel meal in diets except for percentage fat cuts which decreased significantly (P < 0·05) as the dietary levels of palm kernel meal were increased.
Physiological studies on the leaf blades of wheat (Triticum aestivum L.) in relation to nitrate assimilation and grain protein accumulation
Authors: Nair T. V. R. , Abrol Y. P. 
Published: March 2009

SUMMARYTwo wheat (Triticum aestivum L.) cultivars, Shera and Kalyansona, which differ in grain protein percentage and in its enhancement by fertilizer application were selected for the present study. The analysis was confined to the leaf blades of the main shoot of plants grown at three rates of application of urea giving 0 (N0), 90 (N90) and 180 (N180) kgN/ha. Cv. Shera produced ten leaf blades on its main shoot while cv. Kalyansona had 11. The total dry weight duration of the leaf blades of cv. Kalyansona was higher than that of cv. Shera, particularly at N90 and N180. This was due to a great increase in dry weight of the leaf blades in response to fertilizer nitrogen and to an additional leaf blade. In both the cultivars the in vivo nitrate reductase (NR) activity was highest in the first formed leaf blades and showed a gradual decline in the successively formed ones, at all three nitrogen levels. Cv. Shera showed higher NR activity than cv. Kalyansona in most of the weekly samplings (weighted mean values) through the season. Seasonal mean NR activity was higher in cv. Shera at all three rates of nitrogen application. The difference was, however, significant only at N90. The total amount of NO3- reduced by the leaf blades, which is a function of their NR activity and dry weight duration, was higher in cv. Shera than in cv. Kalyansona at N0. However, at N90 and N180 the differences decreased because of the higher dry weight duration of the leaf blades of cv. Kalyansona.The estimated amount of NO3- assimilated was less than the actual reduced N at harvest at N0 but at N90 and N180 there was an overestimation. The grains of cv. Kalyansona showed significantly lower protein percentage than cv. Shera at all three nitrogen levels. While low nitrogen per spike was the main cause of lower protein percentage in cv. Kalyansona at N0 as compared with cv. Shera, distribution of almost the same amount of nitrogen to a larger quantity of grains was largely responsible for the lower protein percentage in this cultivar at N90 and N180. The results are discussed in relation to selection criteria used in breeding programmes for the improvement of grain protein content of wheat cultivars
Studies of the cattle of Northern Rhodesia: I. The growth of steers under normal veld grazing, and supplemented with salt and protein
Authors: Walker C. A. 
Published: March 2009

1. With steers of indigenous cattle, the supplementation of veld grazing with two levels of salt with and without protein in the dry season has been investigated.2. The feeding of 1 oz. of salt speeded up growth to a strongly significant degree, but under the experimental conditions no benefit was obtained during the dry season from adding a protein supplement to the salt. Protein supplementation without salt produced no significant effects upon growth.3. The addition of 2 oz. of supplementary salt was found to give some increase in growth when compared with the control, but appeared to exert an inhibitory action as compared with the lower salt level, and again there was no benefit gained from the addition of a protein supplement in the dry season. No reason can yet be given for this.4. Additional evidence has been given to support the suggestion that the tropical indigenous animal possesses the capacity to stop growing during adverse nutritional conditions.
Seasonal variation in the egg production of fowls: effect of temperature and change of day length
Authors: Hutchinson J. C. D. , Taylor W. W. 
Published: March 2009

1. Two groups of pullets were reared on a 12 and a 23½ hr. day length respectively and at an environmental temperature of 64–65° F. Two months after the first bird came into lay, the day length of the second group was reduced to 12 hr. over a period of about 8 weeks (phase I).2. Both groups came into production at the same time, but the group reared on a 23½ hr. day grew more rapidly.3. The reduction in day length caused moulting and low production for several months, whereas the group which had been reared in a 12 hr. day continued to lay steadily.4. Soon after the reduction of day length half of each group (subgroups B and D) was exposed to an artificial thermal autumn and winter, which had no detectable effect on production (phase II). After this the temperature was allowed to rise to 64–65° F.5. When the day length of the remaining birds (subgroups A and C), still kept at 64–65° F., was increased to 23½ hr., there was no significant increase in production (phase III).6. When their day length was then reduced to 12 hr., they moulted heavily and went out of production (phase IV).7. Simultaneously the day length of subgroups B and D was increased to 16J hr. (phase IV). This had no significant effect on production.8. The yield of the birds which had their day length reduced at the beginning of the experiment was twenty-three ovulations less than that of the others at the end of the artificial winter, and nineteen less at the end of the laying year. The laying year was concluded before phase IV. There was no difference in yield between the birds which had an artificial autumn and winter and those which lived in a warm environment.9. Data are given on the frequency distribution of the yield after a reduction in day length, over the remainder of the year, and also on the correlation between the yields in these two periods.10. The eggs of the group reared in a 23½ hr. day length tended to be larger than those of the other group in conformity with their larger body weight. Apart from this the various treatments had no effect on egg weight.11. There was no relation between the egg yields and the variations in absolute and relative humidity.12. In a subsidiary experiment it was found that, if the reduction in day length was completed a month before the birds began to lay, there was no significant effect on subsequent production.13. In the light of these experiments it seems that the essential cause of winter pause and the annual rest, in birds given supplementary lighting, is the decline in day length in late summer and autumn.
The prediction of the voluntary feed intake of dairy cows
Authors: Vadiveloo J. , Holmes W. 
Published: March 2009

SUMMARYInformation on the total dry-matter intake (TDMI), concentrates supplied (C), live weight (LW), week of lactation (WL), milk yield (MY) and composition, quality of forage fed to, and parities of, 385 cows from five different sources were assembled to develop appetite prediction equations. The equations were based on multiple regression and least squares constants and were calculated using the data from each source and the data pooled from all sources. The major factors affecting total dry-matter intake (TDMI) were C, LW, WL and MY and for the pooled data these factors explained 73–76% (R2) of the total variation in TDMI. The predictive values of some of the equations were tested against independent sets of data and for groups of cows and individual cows, the equations predicted TDMI within ±1·1 and 1·6 kg, respectively. The application of the equations in the field is discussed and some suggestions made for increasing the R2 of future appetite equations.
Factors affecting the performance of ewes fed ad libitum until weaning and the performance of their lambs
Authors: Economides S. 
Published: March 2009

Nutritional and other physiological factors are causes of variation in milk yield. In particular, the energy intake and the suckling stimulus of lambs greatly affect the milk yield of ewes in early lactation (Treacher, 1978; Hadjipanayiotou & Louca, 1976; Peart, Doney & MacDonald, 1975).In most eastern Mediterranean countries ewes are milked after weaning and the weaning age and the suckling regime determine both the amount of saleable milk and the rate of growth of lambs. The aim of the present work was to study factors affecting the milk yield of Chios ewes fed ad libitum and the growth of their lambs.
The intensive production of herbage for crop-drying Part VI. A study of the effect of intensive nitrogen fertilizer treatment on species and strains of grass, grown alone and with white clover
Authors: Holmes W. , MacLusky D. S. 
Published: March 2009

1. An experiment is described which lasted for 5 years and in which a comparison was made of twelve grasses or grass mixtures under different fertilizer nitrogen treatments and also when grown with clover. The herbage was cut 4–6 times in each season. Adequate amounts of mineral fertilizers (280–340 lb. K2O and about 100 lb. P2O5 per acre per annum), and the following nitrogen treatments were applied: (1) no nitrogen, no clover, (2) grass sown with clover, (3) 140–208 lb. nitrogen per acre per annum in four to six equal dressings, (4) 350–416 lb. nitrogen per acre per annum in five and six equal dressings.In 1951, 1952 and 1953 the clover dominant swards (treatment 2) were split between the following treatments; (X) as (3) above, (Y) 35 lb. nitrogen per acre in spring and again in late summer, (Z) no nitrogen as (2) above.2. The average yields for the 4 years were 2180, 5940 and 8300 lb. dry matter per acre, and 290, 850 and 1460 lb. crude protein per acre for treatments 1, 3 and 4. With treatment 2 the average yields were 2830 lb. dry matter and 400 lb. crude protein in 1949 and 4270 lb. dry matter and 820 lb. crude protein in 1950. An approximate average yield for the 4 years from treatment 2 was 4630 lb. dry matter and 860 lb. crude protein. In 1951–3 average yields for treatments 2X, 2Y and 2Z were, 7240, 6340 and 5750 lb. dry matter and 1240, 1180 and 1100 lb. crude protein per acre.3. There were considerable differences between grasses in nitrogen response and compatibility with clover. The highest yields with fertilizer nitrogen were given by cocksfoot strains, but, in the presence of clover, ryegrass and timothy strains gave the highest yields. There were also differences between strains within each species.4. Mean crude protein contents were, for treatments 1, 3 and 4, 13·3, 14·3 and 17·6%, and for treatments 2X, 2Y and 2Z in 1951–3, 17·2, 18·6 and 19·1%. Differences between species were significant in only a few instances.5. The distribution of yield over the season was most regular with treatment 4. Cocksfoot species gave the least variable yields from cut to cut, while those from timothy and ryegrass swards were the most variable.6. Treatments 3 and 4 maintained a high proportion of sown grasses in the swards. In treatment 2 the clover percentage rose to a high level by 1950. A high percentage was maintained under treatment 2Z in 1951–3. Treatment 2Y depressed the clover content in some grasses, and treatment 2X further depressed it in those grasses. A fairly high clover content was maintained, however, even with treatment 2X with some timothy strains and meadow fescue.7. The mineral fertilizers applied maintained the soil analysis at a satisfactory level.8. The results are discussed with special reference to the relative merits of fertilizer nitrogen and clover nitrogen and to the differences between species and strains.