bluuebunny/crossref_metadata_2025 huggingface dataset:
Some Factors Which Influence the Toxicity of UHF Energy to Weed Seeds
Authors: Rice Robert P. , Putnam Alan R.
Published: January 2018

UHF energy (2450 MHz) was applied to seeds and seed-soil mixtures with a waveguide under controlled conditions. After treatment, seeds were germinated at 27 C to determine viability. Seeds were either killed or seedlings grew normally with no intermediate levels of inhibition typical of that produced with sub-lethal dosages of herbicides. The energy required to kill several species of dry seeds ranged from 88 to 183 J/cm2and could be reduced 12 to 42% by a 24-hr imbibition period prior to treatment. When several seed-soil mixtures were treated, the greatest toxicity occurred in a moist muck and clay loam soil, with the least toxicity on a dry loamy sand soil. Although attenuation of activity occurred in dry soils of three types, less energy was required to kill seeds in moist soils than was required in the absence of soil. Increasing the power levels reduced the time of exposure necessary to kill barnyardgrass [Echinochloa crus-galli(L.) Beauv.] seeds. Less energy was required to kill seeds as the soil temperature was increased from −20 to +18 C.
Degradation and Field Persistence of Imazethapyr
Authors: Goetz Andrew J. , Lavy Terry L. , Gbur Edward E.
Published: January 2018

The volatilization, photolysis, microbial degradation, and field persistence of imazethapyr were studied using formulated and14C-labeled imazethapyr. Volatilization losses from soil were less than 2%. Photodecomposition losses of up to 8% occurred from soil and up to 52% from a glass slide with no soil. Significantly greater photodecomposition occurred with chain-labeled than ring-labeled14C-imazethapyr. The amount of14CO2evolution from soil treated with either ring- or chain-labeled14C-imazethapyr was not significantly different. The total14CO2evolved from the soils ranged from 2.4 to 3.6% of the total14C-imazethapyr applied to the soil. However, degradation of imazethapyr from the same soils, as determined by high-pressure liquid chromatography, indicated that 62 to 82% of the applied14C-imazethapyr had been degraded. The degradation rate increased as soil moisture was increased from −100 to −33 kPa. Imazethapyr was more persistent in soil with the higher clay and organic matter content.
High-Temperature Effects on Germination and Survival of Weed Seeds in Soil
Authors: Egley Grant H.
Published: January 2018

Seeds of eight weed species were heated for up to 7 days at 40, 50, 60, and 70 C in dry (2% moisture) and moist (19% moisture) Bosket very fine sandy loam to determine temperature-time treatments lethal to weed seeds. Seeds in dry soil were very tolerant to 60 C or less for up to 7 days but most seeds were killed at 70 C after 7 days. In moist soil, a few (1 to 12%) seeds of common purslane, redroot pigweed, johnsongrass, and spurred anoda survived for up to 3 days at 70 C. Some (4 to 30%) seeds of velvetleaf, pitted morningglory, and the above species survived up to 7 days at 60 C. No seeds of prickly sida and common cocklebur survived more than one-half day at 60 C. Three days at 50 C were lethal to all cocklebur seeds. Many of the sublethal treatments promoted germination of prickly sida, velvetleaf, spurred anoda, and pitted morningglory, presumably because high temperature broke dormancy of some hard seeds. The enhanced effect of heat treatments upon seeds in moist soil compared to seeds in dry soil was due to the higher moisture content of seeds, or in fruit tissues of dispersal units in moist soil. Because some seeds survived several days in moist soil at 60 and 70 C, it is unlikely that soil solarization or other natural methods of raising soil temperature will eliminate weed seeds from the field. However, high soil temperatures may reduce weed seed populations by killing heat-susceptible seeds and by breaking dormancy of hard seeds followed by thermal kill of seedlings.
Bioeconomic Weed Management Models for Sugarbeet (Beta vulgaris) Production
Authors: Shribbs John M. , Lybecker Donald W. , Schweizer Edward E.
Published: January 2018

Bioeconomic sugarbeet weed management models for preplant, postemergence, and layby herbicides, and late-season handweeding decisions are presented. The personal computer/spreadsheet models are based on number of weed seed in soil, field survey of weed populations, growth stages of weeds and sugarbeets, expected yield loss from weeds, herbicide weed control, weed control cost, and sugarbeet price. The models incorporate two producer risk levels. Several weed scenarios were used to verify the models for reasonable recommendations.
Germination and Emergence of Hairy Beggarticks (Bidens pilosa)
Authors: Reddy Krishna N. , Singh Megh
Published: January 2018

Effects of environmental factors on germination and emergence of hairy beggarticks were examined in laboratory and greenhouse studies. Optimum temperature range for germination of hairy beggarticks was 25/20 to 35/30 C (day/night, 12/12 h). Germination decreased above or below this range. Temperatures below 15/10 C and above 45/40 C were unfavorable for germination. Hairy beggarticks seed can germinate under both a 12-h photoperiod and a 24-h dark regime. Seed germinated 78 to 90% in buffer solutions of pH 4 to 9. Radicle growth was more sensitive to extreme pH than germination. Osmotic stress up to −0.1 MPa had little effect on germination, but less than 3% of the seed germinated at an osmotic stress of −0.75 MPa. Hairy beggarticks seed (13%) germinated at NaCl concentration of 100 mM but failed to germinate at 200 mM NaCl. Maximum emergence occurred when seed were planted less than 1 cm deep. No seedlings emerged when planted 10 cm deep. Flooding even for a day following planting decreased emergence to 25% compared to no flooding (56%). Seedling emergence decreased sharply with a further increase in duration of flooding, and no seedlings emerged when flooding was maintained up to 28 d after planting.
Competition for Light Between Tomatoes and Nightshades (Solanum nigrumorS. ptycanthum)
Authors: McGiffen Milton E. , Masiunas John B. , Hesketh John D.
Published: January 2018

The effect of black and eastern black nightshade on the amount of photosynthetically active radiation (PAR) intercepted by a processing tomato canopy was studied along with the correlation between PAR and tomato growth and yield. During 1989 and 1990, black and eastern black nightshade were established at densities of 0 to 4.8 m−2within rows of transplanted, irrigated processing tomatoes. Increasing the density of either nightshade species decreased the number of tomato fruit; however, eastern black nightshade reduced tomato yield more than black nightshade. Eastern black nightshade was taller than the tomatoes, reducing PAR reaching the top of the tomato canopy. PAR reaching the top of the tomato canopy was positively correlated with yield and negatively correlated with eastern black nightshade density. Eastern black nightshade intraspecific competition decreased both stem and berry weight. Black nightshade was never taller than tomatoes and did not affect PAR reaching the top of the crop canopy. Increasing the density of black nightshade decreased berry dry weight but increased the weight of stems and leaves.
Effect of Application Rate, Weed Species, and Weed Stage of Growth on Imazethapyr Activity
Authors: Klingaman Tracy E. , King Charles A. , Oliver Lawrence R.
Published: January 2018

Field experiments were conducted in 1986, 1987, and 1988 to evaluate imazethapyr rate and time of application on postemergence control of 24 weed species. Contour graphs were developed that predicted imazethapyr rates required for various levels of weed control based upon weed leaf number at application. Rates below the labeled rate (70 g ha−1) provided 90% or greater control of common cocklebur, smallflower morningglory, and smooth pigweed if applied to 3 true-leaf or smaller weeds and of barnyardgrass, seedling johnsongrass, and Palmer amaranth if applied while weeds were in the cotyledon or 1 true-leaf stage. A rate of 70 g ha−1provided 90% control of large crabgrass in the 1 true-leaf stage. Entireleaf morningglory, red rice, pitted morningglory, and velvetleaf are not susceptible enough to imazethapyr for 90% or greater control to be obtained with rates lower than 70 g ha−1at the 1 true-leaf growth stage. These data demonstrate how control data can be used for developing effective reduced-rate herbicide recommendations based on weed leaf number.
Cotton (Gossypium hirsutum) Yield Response to Mechanical and Chemical Weed Control Systems
Authors: Snipes Charles E. , Mueller Thomas C.
Published: January 2018

Cotton yield response was evaluated in 1987, 1988, and 1989 when weeds were managed with preemergence fluometuron [none (0%), band (50%), or broadcast (100%) surface coverage], cultivation (none, one, two, or three times), and postdirected fluometuron + MSMA. Weed densities (primarily prickly sida, morningglories, and hemp sesbania) varied widely among years and were directly related to early season rainfall. Postdirected herbicide application or cultivation(s) had little effect on weed density. The use of a banded fluometuron application reduced weed biomass 28 to 47%. A further decrease was observed when preemergence fluometuron was increased from banded to broadcast coverage. Seed cotton yields were low with no preemergence fluometuron. Banded fluometuron and at least one cultivation had yields similar to broadcast fluometuron only. Cotton yields were related to weed density and weed biomass in a hyperbolic relationship. Low weed densities caused more yield loss per unit weed density than higher densities.
Foliar Absorption and Translocation of Herbicides from Aqueous Solution and Treated Soil
Authors: Al-Khatib Kassim , Parker Robert , Fuerst E. Patrick
Published: January 2018

It has been suggested that soil treated with a herbicide and subsequently carried by wind and deposited on plant foliage can cause crop injury. This study compared foliar uptake and translocation of herbicides applied to plants as an aqueous solution or in herbicide-treated soil. Leaves of 3-wk-old seedling alfalfa, grape, and pea were treated with14C-labeled thifensulfuron, chlorsulfuron, glyphosate, 2,4-D, and bromoxynil. Significant amounts of all herbicides were absorbed by pea, alfalfa, and grape from the aqueous solutions, whereas very limited absorption occurred from herbicide-treated soil. Prolonged and multiple exposure to herbicide-treated soil did not increase herbicide uptake. High relative humidity enhanced herbicide absorption from aqueous solutions but not from herbicide-treated soil. All herbicides except bromoxynil were readily translocated in alfalfa, grape, and pea. Limited quantities of herbicides were absorbed from herbicide-treated soil by plant foliage, and this small amount is unlikely to cause crop damage.
Modeling the Effects of Weed Interference Periods and Insects on Bell Peppers (Capsicum annuum)
Authors: Frank J. Ray , Schwartz Paul H. , Potts William E.
Published: January 2018

Field experiments were conducted at Frederick, MD, in 1985 and 1986 to determine effects of weed-interference periods and insects on bell peppers. Weed-interference periods of approximately 40 and 60 d reduced both bell pepper fruit number and weight 10 and 50%, respectively. Bell pepper foliage weight was reduced 10 and 50% with approximately 20- and 50-day weed-interference periods. In 1985 and 1986, insect populations were low with an average of 10 and 3% of the pepper fruit infested, respectively. Most infested fruit was damaged by European corn borer. No significant differences in insect infestation of fruit as related to time of weed-interference periods were noted.
Propagation ofEuphorbia esulafor Leafy Spurge Biocontrol Agents
Authors: Lym Rodney G.
Published: January 2018

Efforts to screen and mass-rear insects and diseases for leafy spurge biocontrol agents have been hampered by low success in propagation and slow growth of leafy spurge in the greenhouse. The optimum greenhouse conditions for leafy spurge growth were determined. Leafy spurge was propagated from stem tip cuttings, with the basal end treated with 0.2% NAA, and the plants misted with water for 10 d. Optimum conditions for growth were 27 C air temperature, application of a complete fertilizer at 70 kg ha−1weekly or 135 kg ha−1biweekly 20 d after stem tip propagation, in a peat/perlite/vermiculite growth medium at pH 7 and a 16-h photoperiod. Regrowth from roots of parent plants was improved when cuttings were taken from plants at least 60 d old, and plants grew nearly twice as rapidly when the medium was maintained at 30 C compared to 22 C. Refrigeration of stem tip cuttings or roots before planting did not affect survival or growth vigor. Only gibberellic acid of nine plant growth regulators evaluated increased growth, but plants were etiolated. Biotypes from Nebraska and South Dakota were shorter than five others from the United States or Austria but had similar root and shoot dry weight. The time required to propagate vigorous leafy spurge was reduced to 2 mo compared to 6 mo required prior to the study.
Comparative Detoxification of Chlorsulfuron in Leaf Disks and Cell Cultures of Two Perennial Weeds
Authors: Swisher Beth A. , Weimer Monte R.
Published: January 2018

Phytotoxicity of chlorsulfuron {2-chloro-N-[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino] carbonyl] benzenesulfonamide} in cell cultures of Canada thistle [Cirsium arvense(L.) Scop. # CIRAR] was approximately 30-fold greater than in leafy spurge (Euphorbia esulaL. # EPHES) cultures. Differences in chlorsulfuron phytotoxicity in these two species were attributed to large differences in cellular metabolism of the herbicide. Leafy spurge cells metabolized all of the applied14C-chlorsulfuron within 72 h of treatment, while Canada thistle metabolized less than 2%. Acid hydrolysis of the metabolic products isolated from leaf disks and cell cultures of leafy spurge yielded a radioactive product that cochromatographed with a 2-chlorobenzenesulfonamide standard. Therefore, metabolic transformation occurred on the heterocyclic portion of the molecule. A major metabolite was further characterized as 2-chloro-N-[[4-(hydroxymethyl)-6-methoxy-1,3,5-triazin-2-yl]aminocarbonyl]-benzenesulfonamide by cochromatography with the authentic standard.
Postemergence Grass Control in Peanut (Arachis hypogaea)
Authors: Grichar W. James , Boswell Thurman E.
Published: January 2018

CGA 82725 {2-propynyl [2-[4-[(3,5-dichloro-2-pyridinyl)oxy)] phenoxy] propanoate}, haloxyfop {2-[4-[[3-chloro-5-(trifluoromethyl)-2-pyridinyl] oxy]phenoxy] propanoic acid}, sethoxydim {2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one}, and fluazifop {(±)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl] oxy] phenoxy] propanoic acid} were applied postemergence to Texas panicum (Panicum texanumBuckl. # PANTE), large crabgrass [Digitaria sanguinalis(L.) Scop. # DIGSA], and broadleaf signalgrass [Brachiaria platyphylla(Griseb.)Nash. # BRAPP] in peanut (Arachis hypogaeaL. ‘Florunner’). Fluazifop applied at 280 and 410 g ai/ha, sethoxydim at 340 g ai/ha, haloxyfop at 140 g ai/ha, and CGA 82725 at 280 g ai/ha usually gave better control when applied to annual grasses in the two- to four-leaf stage than when applied at the six- to eight-leaf stage. Higher rates of application were required to provide acceptable weed control at the later stage of growth. Peanut yields were usually higher following the early applications, indicating that timing of application is important in obtaining improved yields.
Allelopathic Effects of Sweet Potatoes (Ipomoea batatas) on Yellow Nutsedge (Cyperus esculentus) and Alfalfa (Medicago sativa)
Authors: Harrison Howard F. , Peterson Joseph K.
Published: January 2018

Greenhouse and laboratory studies were conducted to determine the allelopathic potential of two sweet potato [Ipomoea batatasL. (Lam.)] cultivars, ‘Regal’ and ‘SC 1149-19’. Yellow nutsedge (Cyperus esculentusL. # CYPES) and alfalfa (Medicago sativaL.) plants grown in soil from sweet potato field plots accumulated less dry matter than plants grown in soil from adjacent weedy plots. Growth of yellow nutsedge and alfalfa plants was also reduced when grown in a potting medium containing decomposing sweet potato plants in comparison to plants grown in potting medium alone. When the sweet potato potting medium mixture was incubated at 25 C and tested weekly using an alfalfa growth bioassay, inhibition was high initially but decreased over time and was not observed after a 12-week incubation. Aqueous methanol (50%)-soluble extracts of sweet potato periderm were inhibitory to yellow nutsedge root growth in vermiculite and alfalfa seed germination on filter paper. Regal extracts were inhibitory to yellow nutsedge root growth at a concentration of 2.5 mg periderm extracted/ml, but SC 1149-19 extract was inhibitory only at a concentration eight times higher. Similar differences between cultivars were observed with the alfalfa germination bioassay. Preliminary separation of the Regal periderm extract by paper chromatography indicated the presence of phenolic compounds with a wide range of polarities. Several of these UV-visible compounds were inhibitory to alfalfa germination.
Historicizing Iron: Charles Driver and the Abbey Mills Pumping Station (1865-68)
Authors: Dobraszczyk Paul
Published: January 2018

Victorian architects and architectural theorists made a clear distinction between ‘building’ and ‘architecture’; for them, a building became architecture when historical references were invoked. The development of new constructive materials, in particular cast iron, directly challenged this perceived distinction. A new material possessed no history; how, therefore, could it be architectural? This paper will address this question by focusing on the treatment of cast iron in a particular building – the Abbey Mills pumping station, of 1865–68 (Fig. 3) – assessing, for the first time, the contribution of its architect Charles Driver (1832-1900). By also referring to Driver’s published writings, this paper will assess how he sought, in this building, to invest cast iron with architectural, and therefore historical, meaning.
Bi-criteria minimization with MWVN–INAM type for motion planning and control of redundant robot manipulators
Authors: Guo Dongsheng , Li Kene , Liao Bolin
Published: January 2018

This study proposes and investigates a new type of bi-criteria minimization (BCM) for the motion planning and control of redundant robot manipulators to address the discontinuity problem in the infinity-norm acceleration minimization (INAM) scheme and to guarantee the final joint velocity of motion to be approximate to zero. This new type is based on the combination of minimum weighted velocity norm (MWVN) and INAM criteria, and thus is called the MWVN–INAM–BCM scheme. In formulating such a scheme, joint-angle, joint-velocity, and joint-acceleration limits are incorporated. The proposed MWVN–INAM–BCM scheme is reformulated as a quadratic programming problem solved at the joint-acceleration level. Simulation results based on the PUMA560 robot manipulator validate the efficacy and applicability of the proposed MWVN–INAM–BCM scheme in robotic redundancy resolution. In addition, the physical realizability of the proposed scheme is verified in practical application based on a six-link planar robot manipulator.
The Hidden Gaps in Rural Development: Examining Peasant–NGO Relations through a Post-earthquake Recovery Project in Sichuan, China
Authors: Liu Qing , Wang Raymond Yu , Dang Heping
Published: January 2018

While much of the scholarly work on the development of non-governmental organizations (NGOs) in China focuses on their relations with the state, this paper adopts an anthropological approach to explore previously understudied peasant–NGO relations through the lens of a village-level post-earthquake recovery project in Sichuan. The findings highlight three main types of gaps between the NGO and local villagers: the gaps between the villagers’ immediate needs and the NGO's long-term development plan; the gaps between the villagers’ pragmatic concerns and the “building a new socialist countryside” campaign; and the gaps between the private and collective economies. In spite of the project's unsatisfactory outcome, the NGO did not consider the project a failure. We argue that these gaps were, to a great extent, attributable to the continuing development of the institutional values of NGOs, which guide the transition of Chinese NGOs from traditional charities to modern philanthropic organizations.
Effect of Feeding Juice Extracted from Ensiled Grass after Varying Times of Fermentation on the Voluntary Food intake of Chopped Hay by Sheep
Authors: Rooke J.A. , Offer N.W.
Published: January 2018

The voluntary intake of grass silage (VFI) is influenced by the presence of silage fermentation products. Ammonia-N concentration has been used in prediction equations for silage VFI as an indicator of the negative effects of fermentation products upon VFI but accounts for only a small proportion of the variance. The objective of this experiment was to improve understanding of the factors in silage that limit VFI by relating the time-course of the silage fermentation to the development of intake characteristics.

Second cut perennial ryegrass was precision chop harvested without wilting. The grass was ensiled untreated (C) or treated (I) with 106Lactobacillus plantarum / g grass (Ecosyl, Zeneca Bio-Products) in 200 l containers (10 / treatment). Two containers / treatment were frozen immediately (0) or after 0.2, 1, 2 or 42 days fermentation to give 10 treatments. Juice was extracted using a cider press from silage immediately on thawing, bulked and then re frozen until required for feeding. For feeding, juice was thawed and maintained at 4° until fed.
The Effects of Dietary Addition or Intraruminal Infusion of Amines or Juice Extracted from Grass Silage on the Voluntary Intake of Steers Offered Grass Silage
Authors: Dawson L E R , Mayne C S
Published: January 2018

The dry matter (DM) intake of ruminants offered grass silage is normally less than that of animals offered fresh grass or hay produced from the same sward. End products of fermentation including acids and nitrogenous constituents have been implicated in this depression (Gill, Rook and Thiago, 1988). The aims of the present study were to examine the possible role of amines and juice expressed from silage in silage intake control and to determine if their effect, if any, was due to either oropharyngeal factors or post ingestive mechanisms.
The Effect of a Teaser Bull on the Return to Oestrus of Postpartum Spring Calving Suckler Cows
Authors: Pullar Duncan , Rowlinson Peter , Miller Cheryl , Scatcherd Joanne
Published: January 2018

The successful re-breeding of suckler and dairy cows is vital to the economics of farming cattle. The gestation length of cows is 280-290 days, so the optimum interval after calving for the subsequent mating is 75-85 days if a 365 day calving interval is to be achieved. Average calving rates to a given service are of the order of 0.5 to 0.6 (Diskin and Sreenan, 1980). Most practical management strategies allow cows to be mated during a 7-10 week period (giving 3 or 4 opportunities to show oestrus). The chance of conception improves with each oestrus cycle following calving, so the earlier a cow begins to show oestrus activity after calving the more likely she is to be successfully mated, because the early, less fertile oestrus cycles, are likely to happen before the planned mating period.
Whole-body fat metabolism in cattle fed forage-based diets.
Authors: Greathead H.M.R. , Dawson J.M. , McAllan A.B. , Buttery P.J.
Published: January 2018

The production performance of cattle fed forage-based diets, particularly conserved forages, is poor and unpredictable. It has been shown that protein deposition is limiting in silage-fed cattle (Gill et al., 1987). It has also frequently been reported that the ratio of carcass fat:protein in silage-fed cattle is high (Baker, Young & Laws, 1992). There are few comparative dietary studies on whole-body fat metabolism in cattle. It was therefore the aim of this study to measure some of the parameters of whole-body fat metabolism in cattle fed forage-based diets and thus to determine if the high fat:protein ratio of silage-fed cattle is due to altered rates of whole-body fat metabolism. It was also our aim to determine whether the well-documented effects of β-agonists on fat metabolism are dependent on dietary status.
The Effect of Concentrate Type and Supplementary Lactic Acid or Soya-Oil on Milk Production in Dairy Cows Offered Restricted or Extensively Fermented Grass Silages
Authors: Doherty J G , Mayne C S
Published: January 2018

Several studies have shown increased silage dry-matter intake (SDMI) and improved milk fat concentrations in dairy cows offered restricted fermented grass silages compared to more extensively fermented silages. A recent study suggested that differences in silage intakeper serather than an alteration in rumen fermentation may be responsible for the changes in milk composition observed in the previous studies (Doherty and Mayne, 1993). The aim of the present study was to examine the effect of changes in concentrate composition on milk production parameters in dairy cows offered grass silages of contrasting fermentation type.

Two direct cut grass silages were prepared using either an inoculant, containing a single strain ofLactobacillus plantarum, (Ecosyl, 3 1/t fresh weight, Zeneca Products Ltd) or a mixture of aliphatic carboxylic acids (Maxgrass, 6 1/t fresh weight, BP Chemicals Ltd). Two concentrates (high starch or high fibre) were formulated containing either: barley, 300; wheat, 355; and soyabean-meal, 270 g/kg (high starch) or unmolassed sugar-beet pulp, 555; citrus pulp, 100; and soyabean-meal, 270 g/kg (high fibre).
The response of dairy cows given high levels of molasses to dietary levels of fermentable
metabolisable energy
Authors: Yan T. , Roberts D.J.
Published: January 2018

Unprotected tallow is used as a feed ingredient to meet the energy requirement of high milking dairy cows, but its hydrolysed free fatty acids in the rumen can inhibit microbial activity and dietary fibre digestion. However, the negative effects of the tallow could be minimized when high levels of molasses are also fed since feeding molasses could shorten the retention time of the hydrolysed free fatty acids in the rumen. In addition, molasses contains a large proportion of non-structural carbohydrates (sugars) which have fast fermentation rates in the rumen. When a diet is formulated to have a low fermentable metabolisable energy (FME) concentration, supplementing with a high molasses level may partially make up the deficiency of the energy requirement of the microorganisms in the rumen of dairy cows. Previous experiments have showed that molasses could be fed to dairy cows up to 312 g/kg DM without adverse effect (Yan and Roberts, 1992) and a crude protein level at 160 g/kg DM in the diet containing 310 g/kg DM of molasses was satisfactory for feed intake and milk production of dairy cows (Yan and Roberts, 1993). The current experiment was subsequently undertaken to investigate the response of dairy cows given high levels of molasses to dietary levels of FME produced by altering unprotected tallow concentrations in diets.
The Effect of Food Deprivation on the Expression of Foraging and Exploratory Behaviour in the Pig
Authors: Day J. E. L. , Kyriazakis I. , Terlouw E. M. C. , Lawrence A. B.
Published: January 2018

Growing pigs spend considerable time orally manipulating their environment, which can include their pen-mates. In certain situations this leads to problems such as tail-biting. It is unclear if this active behaviour represents foraging or exploratory motivation, a problem exacerbated by the possibility that both share certain behavioural elements. The aim of this experiment was to distinguish appetitive foraging (extrinsic exploration) from intrinsic exploration by manipulating both feeding motivation and the content of the external environment. The objective was to discover which behavioural elements are common to either behavioural category. This would allow hypotheses to be proposed concerning the causation of oral-manipulation of the environment and inappropriate stimuli such as pen-mates, and furthermore to control for the effects of intrinsic exploration in continuing experiments concerning foraging behaviour.
Effect of Supplementing grass Silage with Sugar beet feed on Methane Production by Sheep
Authors: Moss Angela R. , Deaville E. R. , Givens D. L
Published: January 2018

Methane production by ruminant animals is an important anthropogenic source of methane to the atmosphere and is considered an important source to more accurately estimate and to control. It has been known for some time that, in ruminants, diet type and composition can influence methane production, yet there is little quantitative information for contemporary diets used in the UK. Attempts to predict methane production from either diet chemical composition or digestibility have not been successful (Moss and Givens, 1990; Johnson et al., 1991). In order to estimate more accurately the amount of methane produced by a ruminant on a given diet, it is essential to establish whether there are interactions of various substrates with forage and to relate this to the rumen environment. Previous work showing interactions has used mainly hay-based diets (Blaxter and Wainman, 1964); as grass silage is now the major forage in the UK, work with this forage was undertaken.
Effect of Diet on Behaviour of Individually Penned Sheep
Authors: Cooper J.J. , Emmans G.A. , Friggens N.C.
Published: January 2018

A number of abnormal activities had been observed in a group of 30 lambs (R lambs; 10 Shetland (SH),10 Scottish Blackface (SB) and 10 Welsh Mountain (WM), half females and half entire males), on a restricted allowance (about mature maintenance intake and 0.5 of ad libitum intake), of a high quality pelleted diet (Diet A; 200g/kg crude protein, HMJ/kg ME). The lambs had been individually housed since 8 weeks of age, in pens (2m x lm), made up of metal barred gates with wooden slatted floors. Abnormal oral activities included some that caused obvious husbandry problems, such as wool-biting and slat chewing, and others which caused no overt damage, but may nevertheless be associated with impaired welfare (Cooper and Nicol 1993), such as bar-biting and repetitive licking. In a preliminary observation at 22 weeks of age, lambs only ate in the hour following food presentation (Fig 1), after which all of the allowance had been eaten, and abnormal oral activities were recorded in 30% of scans. Similar repetitive activities, described as “stereotypies” have been associated with food restriction in dry sows (Appleby and Lawrence 1987). In a series of observations, we investigated the effect of increasing weight and nutrient value of the lamb's diet on the incidence of oral stereotypies, whilst minimising any influence on the ongoing feed trial.
Non-Ruminant Production and its Effects on the Environment
Authors: Lee Pauline , Tucker Sue
Published: January 2018

Pollution problems caused by monogastrics occur primarily because of the high numbers of pigs and poultry either in a given area or on individual intensive units. There is a total of approximately 7.6M pigs and 162M poultry which have a total excreta output of about 9.4M tonnes from pigs and 4.6M tonnes from poultry. This is equivalent to a total nitrogen content of approximately 76 and 112 thousand tonnes and a total phosphate content of 47 and 96 thousand tonnes for pigs and poultry respectively. These levels of nitrogen and phosphate are based on chemical analyses of large numbers of slurry and manure samples as spread.
Feed intake and growth rate in growing and finishing steers offered a diet of silage plus concentrates with varying levels of ardacin.
Authors: Keane M.G. , Read M.P.
Published: January 2018

Ardacin is an antibacterial glycopeptide effective against gram positive bacteria. Research elsewhere has shown that in growing calves, it increased the efficiency of microbial protein synthesis and protein flow to the duodenum. In goats it reduced methane production but did not affect the site or extent of organic matter digestion. Results on its effects on feed intake are equivocal but it has been shown to increase liveweight gain in finishing cattle. The objective of the present study was to ascertain the effects of Ardacin on feed intake and growth rate of growing and finishing steers.

Two experiments were carried out simultaneously using the same feeds and Ardacin dose levels. In Experiment 1, 72 Friesian and Charolais x Friesian growing steers (8 months old and 240 kg initial weight) were blocked to 4 treatment groups, tied in individual stalls, and offered grass silage ad libitum plus 1 kg ground barley containing Ardacin per head daily.
Effect of undernutrition on corpus luteum function, jugular and ovarian venous progesterone profiles and endometrial progesterone concentration in sheep
Authors: J.A. Abecia  , S.M. Rhind  , P.J. Goddard  , S.R. McMillen
Published: January 2018

Reduced rates of embryo survival have been shown to be associated with both low levels of food intake and high concentrations of progesterone (P4) in peripheral circulation and high levels of intake with low P4 concentrations.

There is evidence that P4 is transferred from the ovarian vein to the ovarian artery and a branch of this artery supplies the oviduct and upper uterine horn. Thus, P4 profiles in the peripheral circulation may not be indicative of the pattern of P4 supply to the uterus. Since undernutrition results in a reduced LH pulse frequency, which in turn can reduce the secretion of P4, it was postulated that the effect of undernutrition on embryo survival could be mediated through changes in the profiles of LH and so of P4 secretion. It was further suggested that the effects of undernutrition on P4 profiles in the ovarian venous plasma may differ from the effects on jugular venous profiles, and that it is the latter which determines embryo survival rates.
Pregnancy associated glycoprotein and progesterone concentrations in plasma of sheep during gestation and postpartum period
Authors: Ranilla M.J. , Sulon J. , Carro M.D. , Mantecón A.R. , Beckers J.F.
Published: January 2018

During normal pregnancy in human and various animal species, several proteins and hormones either appear for the first time or are greatly increased in the maternal circulation. One of them, PAG (Pregnancy-Associated Glycoprotein) has been found in cattle, in sheep and in goats (Benitez-Ortiz, 1992). The PAG is now well characterized and highly purified in cattle (bPAG), but there is no information in the literature about its serum concentration profile during gestation in sheep (oPAG). This study was carried out with the aim of studying the pattern of plasma oPAG and progesterone concentrations throughout gestation in two breeds of sheep (Churra and Merino) and to investigate the relationships between PAG and progesterone production.
The Effects of Ewe Diet on Progesterone Concentration and Colostrum Production
Authors: O’ Doherty J.V. , Whittle C.T. , O’ Callaghan D. , Quinn P. J. , Crosby T.F.
Published: January 2018

In well fed ewes with one or two lambs, large volumes of colostrum accumulate in the mammary glands during the last few days of pregnancy and copious milk secretion begins soon after birth. In underfed ewes, prenatal colostrum accumulation is reduced markedly, lactogenesis is delayed. (Mellor and Murray, 1985). Robinson (1985) has shown that there is a sharp increase in the ewe's net protein requirements for udder growth and colostrum production in the last two weeks pre-partum. McPherson, Robinson and Fraser (1981) found that the detrimental effects of a maternal energy deficit on the ewes colostrum supply at parturition can be ameliorated by increasing her supply of amino acids through the provision of a dietary supplement of rumen UDP. The peri-parturient transitions from udder growth to colostrum accumulation and then milk secretion depend largely on withdrawal of progesterone and surges in prolactin, Cortisol and oestrogen, with the progesterone inhibiting and Cortisol potentiating the lactogenic actions of prolactin (Delouis, 1978). The slower progesterone withdrawal in the underfed ewes was associated with a delay in lactogenesis. Thus the objective of this experiment was to study the effects of feeding different diets on ewe colostrum production and quality, and on progesterone concentration pre and post lambing.
The gas production capacity of purified chemicals and feedstuffs when incubated in vitro with rumen microbes as a possible indicator of energy availability in the rumen
Authors: Chamberlain A.J.
Published: January 2018

The metabolisable protein system (AFRC, 1992) introduced the term Fermentable Metabolisable Energy (FME) as a measure of the amount of energy that was available in the rumen to support microbial activity. FME is currently derived from theoretical considerations rather than direct measurement; it is on based metabolisable energy (ME) but does not take into account rumen outflow rates and gives limited consideration to the chemical composition of feeds. Gas production from in vitro fermentation of feeds is an indicator of microbial activity which might be a suitable assessment of the rumen available energy content of feeds.
The use of neural networks to derive prediction relationships for feed composition from near-infra-red monochromator scans
Authors: Chadoulos E A , Bishop J M , Chamberlain A T , Piotrowski C
Published: January 2018

The derivation of predictive relationships from near-infrared scan results is generally performed using regression analysis but for this technique relationships must be a continuous function. Neural networks allow non-functional relationships to be investigated and in other fields have improved prediction quality by 10% - 25%.

Neural networks are an artificial intelligence tool and can be represented as a multi-layered network of nodes connected by vectors (Figure 1), each node receiving one or more inputs which are transformed and combined and then passed on to one or more nodes in the next layer.
Use of the rumen simulation technique (rusitec) to provide micro-organisms for assessing forage rate-of-fermentationin vitro:effect of soluble carbohydrate inputs to rusitec
Authors: Barbi J H T , Owen E , Theodorou M K
Published: January 2018

In previous experiments (Barbi, Owen & Theodorou, 1993; Barbi, Owen & Theodorou, 1994), to minimize the reliance on fistulated animals in feed evaluation, effluent fluid from thein vitrorumen simulation technique (RUSITEC - Czerkawski & Breckenridge, 1977) was used to replace strained rumen liquor as the inoculum for the Pressure Transducer Technique (PTT - Theodorou, Brooks, Dhanoa, McAllan & Gill, 1993). In Barbiet al(1993), two different dilution rates in RUSITEC were compared, whereas in Barbiet al(1994), the effect of increasing the solid food input to RUSITEC was assessed. In both experiments low microbial activity in the RUSITEC effluent fluid affected the PTT results, reducing rates and extent of fermentation profiles to below those in the rumen-liquor inoculated control cultures.

In the present study, mixtures of glucose and xylose, as sources of liquid-phase nutrients, were infused, in differing quantities, into RUSITEC vessels. Also, the effect of adding or not adding a source of solid nutrient (hay) to the effluent collection vessels, was investigated. The objective, in both treatments, was to increase the cellulolytic microbial activity of RUSITEC effluent fluid.
Purine derivatives in urine and plasma of lactating cows given different levels of feed intake
Authors: Daniels Z. M. , Chen X.B. , Kyle D.J. , Sinclair K. , Ørskov E.R.
Published: January 2018

It has been demonstrated in previous work (Chen et al 1993) that the molar ratio of purine derivatives (PD) to creatinine (C) in spot urine samples can be used as an index of microbial protein supply in sheep. This study was to examine the feasibility of using this approach in cattle.

Twelve lactating beef cows were allocated into three groups and each group was fed one of the following levels of restricted feeding: (1) 13 kg fresh weight (FW)/d (high), (2) 10 kg FW/d (medium); (3) 7 kg FW/d(low), given in two equal meals. The diet was pelleted and contained (on fresh weight basis): 0.40 sodium hydroxide treated straw, 0.24 barley, 0.10 soya, 0.25 molassed sugar beet pulp and 0.01 urea. Daily urinary excretion of PD was measured for a week. Two-hourly collections of urine (regarded as ‘spot urine’) were also made over the same period for measurement of PD/C molar ratio. Plasma PD concentration was measured in three jugular blood samples taken on the last day of urine collection. Milk yield was indirectly measured by calf weights before and after suckling. The results were analysed to examine the variability of PD/C in spot samples and the relationship of the spot PD/C measurement with the daily PD output.
Analysis of undried grass silage by near-infrared spectroscopy
Authors: Morris H W , Fisher S , Newbold J R , Wilson S , Ashby C W , Reece M N
Published: January 2018

The analysis of grass silage by near-infrared spectroscopy (NIR) of dried samples is established as a valid alternative to wet chemical methods. Analysis of undried samples offers potential advantages in terms of :d of analysis and accuracy of determination of volatile components, provided calibration equations can be validated against independent populations of silage. Accumulation of analyses for a large number of pies allows relationships between silage nutrient value and management factors such as additive use, which are poorly understood, to be examined.
The effect of concentrate level on performance of dairy sheep offered grass silage ad-libitum
Authors: Ewbank C. , Minter C.M. , Wilkinson R.G.
Published: January 2018

The response of dairy cows offered grass silage to increases in the level of concentrate supplementation is well documented. However little information exists for dairy sheep. The aim of this trial was to assess the impact of concentrate level on silage dry matter intake, milk production and quality and daily liveweight change in milking ewes.

After weaning at 8 weeks, 24 mature Friesland ewes were individually penned. Ewes were offered precision chopped grass silage: (dry matter (DM) 203 g/kg; ph 3.4; ammonia nitrogen 58 g/kg total N; crude protein (CP) 164 g/kg DM; metabolisable energy (ME) 10.9 MJ/kg DM) ad-libitum and concentrate DM (CP 194) g/kg DM; ME 12.8 MJ/kg DM) at daily rates of 0; 0.7, 1.4 and 2.1 kg/day with no more than 0.6 kg per feed. Water was available ad libitum. All animals were milked twice daily through a Fullwood parlour and weighed weekly. Silage was fed daily and refusals removed twice weekly. The experiment lasted 6 weeks and was analysed as a random block design.
Organic dairy farming (ukrofs standards): milk production and stocking rates during the first year of conversion
Authors: Weller R F , Cooper A , McAllan A B
Published: January 2018

The production of organic milk as defined by UKROFS (United Kingdom Register of Organic Food Standards) requires set production standards, the registration of approved producers and a minimum conversion period before the sale of the product. During the period when a farm is being converted to organic milk production the change from using large quantities of inorganic fertiliser to the establishment of swards containing white clover can reduce both the stocking rate and total milk output (Houghton and Poole, 1990), reducing the income from the farm.

An experiment was designed to study the effects of both grazing to pre-determined sward heights and feeding a concentrate supplement on the stocking rates and milk production of a spring-calving dairy herd.
Restricted suckling of dairy cattle in the humid tropics
Authors: Margerison J. K. , Preston T. R. , Phillips C. J. C.
Published: January 2018

Restricted suckling systems are one the most common forms of livestock production in developing countries. In these systems partial milk extraction and calf suckling are combined, resulting in a multi-commodity (milk and meat) production system. These are now being recognised as some of the most efficient and sustainable uses of the available resources in developing countries. These systems provide a more ‘natural’ method of calf rearing, thus maximising animal welfare.

The aim of this experiment was designed to investigate the maternal relationship between cow and calf within a restricted suckling system and evaluate its effect on milk production and reproduction.
The effect of different genetic lifts and gains on milk production on the long term benefits of using new breeding technologies in commercial dairy herds.
Authors: Yates C. M. , Chamberlain A. T. , Rehman T. , Neal H. , Frost B. J.
Published: January 2018

There are now a range of new breeding technologies which are actually or potentially available for use in commercial dairy cows. In order to give a socioeconomic evaluation of these new technologies the effects of the achievable genetic lift and gain must be estimated and their effect upon milk production. This paper has evaluated these effects from both artificial insemination and embryo transfer based technologies.

A simulation model was constructed to estimate the consequences of adopting either A.I. or embryo based technologies on milk production. The model simulated a 100 cow herd over a period of fifteen years, to allow the delayed benefits of using such technologies to reach maturity. The initial herd structure was calculated using a range of estimates of technology success rates (probability of successfully conceiving after one service) and culling rate (14%).
The effect of plane of nutrition on the response by Trypanotolerant cattle to infection with Trypanosomiasis
Authors: Romney D L , Njie A , Holmes P , Gill M
Published: January 2018

Tse-Tse flies inhabit over 11 million km2 of Africa and are vectors of trypanosomes which cause trypanosomiasis in domestic livestock. The disease has a negative effect on productivity and is fatal in non tolerant breeds. The effect of nutrition on response to the disease was studied.

Thirty two N'Dama heifers (initial mean liveweight 113 + 17.0) were offered ad libitum andropogon hay plus 10.2 g/kg LW groundnut hay (GNH) (L) or GNH and 3.9 g/kg LW groundnut cake (GNC) (H). After 4 weeks on diet, half of each group were inoculated intradermally with trypanosomes (T. Congolense) (LI and HI). Intake was measured daily and liveweights weekly, while thrice weekly blood samples were examined for parasitaemia and packed cell volume (PCV).
Response of breeding sows to long term dietary supplementation with folic acid
Authors: Lynch P.B. , Sheehy P.J.A.
Published: January 2018

Dietary supplementation with folic acid has been shown to improve reproductive performance in sows (Lindemann 1993). However most studies have been for one cycle only and few have examined the effect of supplementation over several parities.

One hundred and thirty four crossbred sows ranging in parity from 2 to 4 were selected at farrowing and randomly allocated to two dietary treatments of low and high supplemental folic acid (0 and 10 g per tonne, Roche Products Ltd.). Treatments were applied for the following three lactations and post weaning periods, two full pregnancies and to day 30 of the pregnancy following the third lactation. The diet fed contained barley, wheat, soyabean meal and meat and bone meal with nutrient levels of 14.0 MJ DE/kg and 1.02% lysine. Sows were individually penned throughout with restricted feeding in pregnancy (2.2 kg/day increasing to 2.5 kg/day in the final month), and ad libitum in lactation (approx 5.0 kg/day) and post weaning (approx 3.4 kg/day). Blood samples for determination of plasma and red cell folate were taken from 14 sows per treatment on days 4, 50 and 110 of one cycle. These were determined by a microbiological assay (modification of methods of Scott et al 1974 and Wilson and Home 1982).