bluuebunny/crossref_metadata_2025_split huggingface dataset:
Decline in plant and animal production from ageing pastures of green panic (Panicum maximum var. trichoglume)
Authors: Robbins G. B. , Bushell J. J. , Butler K. L. 
Published: March 2009

SummaryThe impact of age on the productivity of sown pastures of green panic (Panicum maximum var. trichoglume cv. Petrie) growing on black earth soil in south-east Queensland was measured from 1976 to 1981. During winter and spring, weaner steers grazed at 2·4 animals/ha on summer-spelled pastures which, in each year, were 1, 2, 3, 4 and 5 years old. Pastures were given 58 kg N/ha as urea each year. Live-weight gain averaged 74 kg/head on 1-year-old pasture but only 35 kg/head on 5-year-old pasture, with most of the reduction in weight gain in winter (June to August) occurring up to age 3 years, and with most of the reduction in spring (September to November) occurring for pastures older than 3 years.The decline in animal production was not caused by changes in species composition of the pasture. Rather, weight gain on older pastures was restricted by pasture quality in winter and by reduced pasture growth in spring, but not by presentation dry-matter yield. The decrease in pasture productivity seemed to be primarily due to reductions in available soil mineral N with age, since the N concentration of plant shoots decreased as a pasture aged. Tt is postulated that the immobilization of N in decomposing grass litter is a primary cause of productivity decline in ageing pastures.
Desodification of a salt-affected soil in plots of various sizes under two modes of water application
Authors: Dahiya I. S. , Grewal K. S. , Dahiya D. J. 
Published: March 2009

SummaryDesodification of a highly saline-sodic, permeable, sandy loam soil was accomplished in 2 × 2 m (S1), 4 × 4 m (S2) and 6 × 6 m (S3) plots under continuous and intermittent ponding. The soil contained large amounts of soluble salts and exchangeable sodium throughout the profile to the water table. The chief salts were chlorides and sulphates of sodium, calcium, and magnesium. The leaching curves with respect to desodification did not differ significantly between the S1, S2 and S3 plots under continuous ponding but did under intermittent ponding. With intermittent ponding, the efficiency of leaching exchangeable sodium in the S1 plots was very significantly higher than that in the S2 and S3 plots, i.e. the leaching efficiency decreased sharply with increased plot size. The leaching efficiency in the S1 plots was significantly greater with intermittent than with continuous ponding, but the reverse was true in the S2 and S3 plots. The results further indicated that there is no need to apply an amendment such as gypsum, mainly because calcium and magnesium present in such soils are adequate to replace the initially high exchangeable sodium during leaching. The displacement of exchangeable sodium in the S1 plots under intermittent ponding was nearly piston-like. With increased plot size, it tended to deviate from this behaviour. It is concluded that under practical situations in which reclamation is accomplished in large plots, the practice of leaching the saline constituents with intermittent ponding would be less effective. Thus, leaching of salts down into the soil with a single heavy irrigation would be more desirable.
Comparative efficiency of different planting methods in intermediate deepwater (15–50 cm) rice
Authors: Reddy M. D. , Ghosh B. C. 
Published: March 2009

SummaryIn rainfed lowland rice areas of intermediate deepwater (15–50 cm), transplanting in greater depths of water (50–60 cm) with clonal tillers (double transplanting) from 20 or 40- to 50-day-old-transplanted crops of similar environment increased grain yield significantly compared with seedlings of the same age (60 or 80- to 90-day-old) from a nursery. The grain yield did not decrease significantly when the clonal tillers were removed at 20 or 40 days after transplanting compared with that of the undisturbed crop. The practice of double transplanting (clonal propagation) increased tiller production and the number of panicles, and the crop could tolerate better the greater depths of water and thereby give greater grain yield.
Effect of preceding legume or cereal on barley grain and nitrogen yield
Authors: Papastylianou I. 
Published: March 2009

SummaryTwo separate short-term rotation experiments were conducted during 1982–5 in order to study the production and effect on subsequent barley of legumes grown in Cyprus. The treatment crops, seven legumes and three cereals, were grown in 1982–3 and in 1983–4 growing seasons and barley was grown in the subsequent growing seasons (1983–4 and 1984–5).Among the treatment crops, cereals gave equal or higher dry-matter yields, but equal or lower nitrogen yields compared with legumes. Barley, the test crop, which followed the treatment crops, gave lower grain and nitrogen yields when following cereals than after legumes. There were differences among legumes in their residual effect on the subsequent crop.
The digestion by cattle of silage and barley diets containing increasing quantities of fishmeal
Authors: Rooke J. A. , Armstrong D. G. 
Published: March 2009

SummaryA 4 × 4 latin-square design experiment was carried out to determine the effects of increasing nitrogen (N) intake by feeding diets containing increasing amounts of fishmeal upon the digestion of organic matter (OM) and N by cattle equipped with rumen and duodenal cannulae. A basal diet (B) containing 600 g silage and 400 g ground barley/kg diet and three diets (BF1, BF2 and BF3) in which increasing amounts of the silage and barley basal diet were proportionately replaced by fishmeal were fed. The mean daily intakes of OM and N when each diet was fed were 4·29, 4·28, 4·22 and 4·20 kg OM and 90, 108, 125 and 143 g N for diets B, BF1, BF2 and BF3 respectively.Neither the amounts of OM entering the small intestine nor those voided in the faeces were altered by the diets fed. Thus mean apparent OM digestibility for all the diets fed was 0·74 ± 0·007 and the proportion of digestible OM intake apparently digested in the rumen was 0·83±0·011.Mean daily concentrations of ammonia N in the rumen were significantly(P <0·01) increased from 85 mg N/l (diet B) to 129 mg N/1 (diet BF3) as fishmeal intake increased.The quantities of non-ammonia N (P<0·05) and of amino acid N (P<0·001) entering the small intestine were significantly increased as more fishmeal was added to the diets fed. As fishmeal intake increased apparent N digestibility was significantly (P<0·001) increased.Neither the quantities of microbial N entering the small intestine daily nor the apparent efficiency of microbial N synthesis within the rumen were increased by the diets fed. The quantities of feed N entering the small intestine daily were significantly (P<0·01) increased as fishmeal intake increased; thus apparent feed N degradability in the rumen was significantly (P<0·05) decreased from 0·84 (diet B) to 0·73 (diet BF3) as fishmeal intake increased. Similarly, the rates of disappearance of N from each of the four barley or barley and fishmeal concentrates when incubated in the rumens of the cattle in porous synthetic fibre bags were decreased as the proportion of fishmeal in the concentrates increased. Thus, the rumen N degradability of the diets fed, when calculated from the rates of disappearance of N from porous synthetic fibre bags placed in the rumen, decreased as fishmeal intake increased.As fishmeal intake increased the amino acid composition of duodenal digesta (expressed as g/kg determined amino acids) changed such that the content of arginine increased (P<0·01) and the content of isoleucine decreased (P<0·01). The concentrations of arginine (P<0·01), leucine and lysine (P<0·05) in blood plasma increased as fishmeal intake increased.
The effect of a light pulse and melatonin, alone or in combination, on the reproductive performance of Finn-cross ewes in spring in Israel
Authors: Amir D. , Thimonier J. , Gacitua H. 
Published: March 2009

SummaryAdult Finn-cross ewes, pregnant from September matings, were kept under natural photoperiod (control, 30 animals) or with an additional exposure to a 1 h long. 300 lux light pulse, 16–17 h after an artificial dawn (light-pulse treatment, 32 ewes) for 2·5 months. After lambing, the supplementary light was discontinued and half of the ewes from each group were injected daily with 2 mg melatonin for an additional 2·5 months.The light-pulse ewes produced heavier lambs and more milk, as can be deduced from the higher rate of growth of their lambs during the first 10 days of life, than the control animals. The light-pulse and/or melatonin treatments delayed the occurrence of the first post-partum ovulation and oestrus (which occurred in the untreated animals about 4 and 6 weeks, respectively, after lambing), by 1–3 weeks. However, more ewes exhibited oestrus and cyclic activity in the light-treated than in the other groups. The fertility in the light-treated group was, consequently, superior to that in the group kept under natural photoperiod, in spite of the similar lambing rate of the mated ewes of the different groups.It is concluded that the light-pulse, but not the melatonin treatment, had a beneficial effect on the reproductive performance of the ewes, as measured by the weight of the newborn lambs, the milk production of the dams during the first 10 days post-partum, and the cyclic activity of the ewes after February lambing in Israel.
The effect of dietary molybdenum and iron on copper status, puberty, fertility and oestrous cycles in cattle
Authors: Phillippo M. , Humphries W. R. , Atkinson T. , Henderson G. D. , Garthwaite P. H. 
Published: March 2009

SummaryTwo experiments were conducted to examine the effects of supplementation of a control diet of barley grain and barley straw containing 4 mg copper (Cu)/kg dry matter (D.M.) either with 5 mg molybdenum (Mo)/kg D.M. or with 500 or 800 mg iron (Fe)/kg D.M. on puberty, fertility and oestrous cycles of cattle. Puberty occurred normally in control, Fesupplemented and control animals on a restricted intake whereas it was delayed by 12 and 8 weeks respectively by Mo supplementation. This effect of Mo was not due to the low Cu status since this was equally low in the Fe-supplemented animals, nor was it due to the reduced growth rate since puberty occurred normally in control animals that had a similar live-weight gain. A significant reduction in the pulsatile release of luteinizing hormone was observed within 11 weeks of the Mo supplementation and before any of the other clinical signs were evident, suggesting that Mo may be affecting puberty by altering the release of luteinizing hormone either directly or indirectly.Mo supplementation significantly reduced the percentage conception rate to 12–33% compared with 57–80% in control and Fe-supplemented animals. This effect was not dependent on the rate of live-weight gain which was standardized across the different treatments at approximately 0·6 kg/day. Within 12 weeks of the replacement of dietary Fe by Mo a lower conception rate occurred; replacing dietary Mo by Fe led to a normal conception rate within 12 weeks without any accompanying changes in Cu status or in the rate of live-weight gain. The plasma Mo concentrations, however, changed significantly during these alterations in dietary supplementation. The pre-ovulatory peak height of luteinizing hormone was significantly lower in animals on the Mo-supplemented diet compared with control and Fe-supplemented animals, but the administration of LHRH did not alter the conception rate.More Mo-supplemented animals failed to ovulate following prostaglandin induced synchronization in comparison with the other treatments, and by the 84th week a significantly greater number of Mo-supplemented animals (12/18) had become anoestrous compared with the other groups (2/30). Cu repletion of these anoestrous Mo animals for a period of 20 weeks did not result in resumption of normal oestrous cycles, but ovulation and oestrus were induced by progesterone and LHRH treatment. Results in the latter part of the study indicated that Mo caused superovulation.These data show that Mo supplementation delayed the onset of puberty, decreased the conception rate and caused anovulation and anoestrus in cattle without accompanying changes in Cu status or in live-weight gain. It is suggested that these effects of Mo are associated with a decreased release of luteinizing hormone that might be due to an altered ovarian steroid secretion.
The influence of anaerobic fungi on rumen volatile fatty acid concentrationsin vivo
Authors: Elliott R. , Ash A. J. , Calderon-Cortes F. , Norton B. W. , Bauchop T. 
Published: March 2009

SummaryElimination of the rumen anaerobic fungi from sheep fed chemically-treated barley straw diets resulted in elevated proportions of propionic acid in rumen liquor (fromca. 0·15 to 0·30). Subsequent inoculation of these sheep with a pure culture of fungus decreased propionate concentrations within 3 days to the levels observed in control animals that possessed abundant fungal populations throughout the experiment.Confirmation that propionate itself was not responsible for the elimination of the fungi was provided by the results of a second experiment in which intraruminal infusions of propionic acid failed to reduce fungal growth or prevent recolonization in sheep previously rendered fungi-free.In a third experiment with sheep fed untreated barley straw, monensin supplementation produced the well known elevation of propionate concentrations. However, this treatment also resulted in the elimination of rumen anaerobic fungi from the animals. The magnitude of the increased concentration of rumen propionic acid, resulting from the elimination of the anaerobic fungal flora, indicates an important role for the fungi in the fermentation of high-fibre diets. In addition, these findings indicate that the well known elevation of propionate levels produced by monensin may likewise be effected directly by removal of the rumen anaerobic fungi.
Effect of preceding crops on the nitrogen requirement of pearl millet and phosphorus requirement of chickpea
Authors: Narwal S. S. , Malik D. S. 
Published: March 2009

SummaryA 2-year field study indicated that pearl millet yielded more when sown after fallow, cow pea and green gram than after maize. Preceding fallow, cow pea and green gram reduced the nitrogen requirement of pearl millet by 40 kg/ha compared with maize. Pearl millet responded linearly up to the highest rate of nitrogen (80 kg/ha). N applied to millet had no residual effect on the subsequent crop of chickpea. The chickpea yield followed the order fallow > green gram ≥ cow pea > maize. Chickpea responded to phosphorus up to 40 kg/ha. Green gram-pearl millet-chickpea proved the most profitable cropping sequence. Continuous cropping and application of nitrogen and phosphorus improved the organic carbon and available phosphorus but decreased the available potassium status of the soil.
High-temperature-adaptedAzospirillum brasilensestrains: growth and interaction response on associative nitrogen fixation, mineral uptake and yield of cheena (Panicum miliaceumL.) genotypes in calcareous soil
Authors: Rai R. 
Published: March 2009

SummaryHigh-temperature-adapted strains RAU 1, RAU 2 and RAU 3 ofAzospirillum brasilenseC 7 were isolated from stepwise transfer to higher temperature (30 to 42 °C). One of the strains (RAU 1) showed more growth, greater nitrogenase and hydrogenase activities at 30 and 42 °C than parental and other temperature-adapted strains. This strain also showed growth and more nitrogenase activity from pH 6·5 to 8·0. Strain RAU 1 showed cross-resistance to penicillin (300/µg/ml) but not to streptomycin, kanamycin, viomycin and polymixin B at 30 and 42 °C. It was demonstrated in field plots in calcareous soil that seed inoculation with RAU 1 enhanced mineral uptake of cheena. Inoculation with RAU 1 led to a significant increase in associative nitrogen fixation, dry weight of roots, grain and straw yield of cheena compared with the uninoculated control with or without applied N, but the effect of seed inoculation with high-temperature-adapted strains was variable with different genotypes of cheena.
The digestion, by sheep, of diets containing different physical forms of rapeseed
Authors: Pallister S. M. , Smithard R. R. 
Published: March 2009

SummaryThe effect of including full-fat rapeseed (Brassica napus, cv. Jet Neuf) into diets for mature wether sheep was studied. A 4 × 4 latin square was carried out with diets containing 4% rapeseed oil in different physical forms: as intact seeds; as a mixture of rapeseed oil and rapeseed meal; or as an extruded rapeseed product. A control diet, containing rapeseed meal but no added oil, was also fed.There was no effect of added oil on rumen fermentation or dietary fibre digestibility. Extrusion had the effect of lowering nutrient availability, both in the rumen and in the small intestine. Total nitrogen digestibility for the diet containing the extruded product was 5% lower than any other diet.All diets produced apparent net gains between mouth and duodenum of ether extract; however, the diet containing dispersed oil and meal was the only one that did not show apparent synthesis of long-chain fatty acids in the forestomach. Apparent disappearances of fatty acids in the small intestine were highest, at 56 and 58 g/day respectively, for the diets containing the extruded product and the intact whole seeds. Extrusion had the effect of reducing apparent biohydrogenation of 18:1 in the forestomach.The use of extruded rapeseed in this experiment showed little benefit over that of intact rapeseed, for sheep, owing to the lower digestion of nutrients for the heated supplement. The free-dispersal of rapeseed oil in the diet, however, may inhibit microbial synthesis in the rumen.
Effect of nitrogen and energy supplements on intake and digestion of oat straw by non-lactating dairy cows
Authors: Fadel J. G. , Udén P. , Robinson P. H. 
Published: March 2009

SummaryUrea with molasses and starch, casein, and fish meal with maize gluten meal were compared with a urea control as different nitrogen and energy sources in straw diets fed ad libitum to four mature non-lactating Swedish Red and White cows in a 4 × 4 latinsquare design. Cows fed fish meal with maize gluten meal had increased neutral detergent (ND) fibre intake, digestibility, and total digestion compared with those fed the urea control. When fed casein, cows tended to have higher ND fibre intake, lower ND fibre digestibility, and higher total ND fibre digestion than the urea control. Cows fed urea with molasses and starch had the same ND fibre intake, lower ND fibre digestibility, and lower total ND fibre digestion than the control. Treatments had no influence on rumen pH, rumen in sacco ND fibre kinetics, rumen residence times and median faecal particle size. Rumen ammonia concentrations were lower for the urea with molasses and starch as well as for the fish meal with maize gluten meal treatments when compared with the urea control. Rumen volatile fatty acid concentrations for supplemented diets were either unchanged or higher than for the control diet.
Effects of farmyard manure and green manures on crop yields and nitrogen needs of potato-based cropping systems in Punjab
Authors: Sharma R. C. , Govindakrishnan P. M. , Singh R. P. , Sharma H. C. 
Published: March 2009

SummaryThe results of a long-term field experiment conducted from 1977 to 1984 on alluvial (Ustochrept) soil of Jalandhar showed positive responses of the crops to N. The responses of potatoes to N were reduced by farmyard manure (FYM), green manure of dhaincha and moong and the responses to the organic manures were also reduced by N. The N responsesof potatoes were, however, not affected by the N applied to preceding maize. FYM was better than the green manures in augmenting total tuber yield, large-grade tuber yield and K concentration in the plants.The N applied to the potatoes showed significant residual effect on succeeding wheat crops, reducing its optimum dose of N by about 50%. The residual effect of N on wheat was highly correlated with nitrate status of the soil. The organic manures applied to potatoes improved the yield of the succeeding wheat but did not differ from each other.The fodder crop of pearl millet raised after 7 years also indicated the superiority of FYM to the green manures. There was a build-up of organic carbon, N, P and K in soil and the build-up was maximal with the use of FYM. The application of N had no effect on the organic carbon and nitrogen status of the soil. N improved the availability of P but decreased that of K.
Phosphorus and calcium metabolism in growing calves with special emphasis on phosphorus homoeostasis: 3. Studies of the effect of continuous intravenous infusion of different levels of phosphorus in ruminating calves receiving adequate dietary phosphorus
Authors: Challa J. , Braithwaite G. D. 
Published: March 2009

SummaryCalves were fed continuously at 4 h intervals an adequate-P diet and were infused intravenously with a solution of phosphate supplying either 0, 3, 6 or 9 g P/day in a 4 x 4 latin-square design experiment. Once steady-state conditions were achieved, rates of flow of P at the reticulum, serum P and Ca concentrations, and urinary excretion rates of P and Ca were measured.The concentration of serum P increased significantly with increased intravenous infusion of P as also did the salivary P secretion. Results suggest that it is the serum P concentration that regulates the secretion of P through saliva. Urinary P excretion, which was low in the control group, increased significantly with increased intravenous loading of P. Substantial urinary P excretion occurred, however, only when the serum P concentration exceeded 2·30 mmol/1, which is probably the renal threshold for P. The serum Ca concentration was unaffected by the intravenous infusion of P and urinary Ca excretion remained negligible on all treatments.
Chlorophyll fluorescence as a rapid test for reaction to urea herbicides in winter wheat
Authors: Harris Margaret , Camlin M. S. 
Published: March 2009

SummaryA simple and rapid test is described which can be used to determine tolerance to metoxuron and chlortoluron herbicides in winter wheat (Triticum aestivumL.) cultivars. Seedlings 5 days old were treated by root application of herbicide for 24 h and tolerant and susceptible cultivars were identified by comparing the chlorophyll fluorescence induction curves for both herbicide-treated and control plants after 7 days. The method was thus capable of detecting cultivar tolerance or susceptibility to the herbicides within 12 days of sowing the seed, providing a rapid and effective screening method. Possible uses for this new test are discussed.