bluuebunny/crossref_metadata_2025 huggingface dataset:
Weed Control in Soybeans by Glyphosate Applied in the Recirculating Sprayer
Authors: McWhorter C.G.
Published: January 2018

Field experiments were conducted to study the feasibility of applying glyphosate [N-(phosphonomethyl)glycine] postemergence for the control of johnsongrass [Sorghum halepense(L.) Pers.], redroot pigweed (Amaranthus retroflexusL.), and hemp sesbania [Sesbania exaltata(Raf.) Cory] in soybeans [Glycine max(L.) Merr.]. Herbicide sprays were directed across the row to weeds growing taller than soybeans in June, July, and August. Herbicide not sprayed on weeds was trapped and reused. Glyphosate at 1.12 and 1.68 kg/ha effectively controlled johnsongrass with little soybean injury and with greatly increased soybean yields. The use of 0.1% surfactant frequently increased the toxicity of glyphosate at 1.12 and 1.68 kg/ha to soybeans, but this adverse effect was overcome by the use of 0.1% anti-drift polymer in sprays. Control of redroot pigweed with glyphosate at 1.12 kg/ha was improved by the use of 0.1% surfactant, but surfactant did not increase control with glyphosate at 1.68 kg/ha. Glyphosate at 1.68 kg/ha, with 0.1% surfactant, was required to provide more than 80% control of hemp sesbania. Glyphosate applied at 1.12 kg/ha in the recirculating sprayer provided equal johnsongrass control, increased soybean yields and caused less soybean injury than when glyphosate at 0.56 kg/ha was applied over-the-top in water or in foam.
Competition of Spurred Anoda, Velvetleaf, Prickly Sida, and Venice Mallow in Cotton
Authors: Chandler J.M.
Published: January 2018

Spurred anoda [Anoda cristata(L.) Schlecht.], velvetleaf (Abutilon theophrastiMedic), prickly sida (Sida spinosaL.) and Venice mallow (Hibiscus trionumL.) competition in cotton (Gossypium hirsutumL. ‘Stoneville 213′) was studied during 1973 and 1974. Cotton height was reduced by full-season competition of all species at a density greater than 32 plants/12 m of crop row. Full-season cotton competition reduced the dry matter production of velvetleaf, spurred anoda, prickly sida, and Venice mallow at weed densities less than 8, 16, 32, or 64 plants/12 m of crop row, respectively. Full-season competition resulted in seed cotton yield reductions by spurred anoda, velvetleaf, and prickly sida at 8, 16, and 64, plants/12 m of crop row, respectively. Competition from 2 weeks after cotton emergence until harvest by spurred anoda at 16 plants/12 m, and velvetleaf or prickly sida at 64 plants/12 m, reduced yields. Spurred anoda, velvetleaf, or prickly sida competition 4 to 6 weeks after cotton emergence until harvest did not reduce the seed cotton yields. Venice mallow competition did not reduce yields at any density or competition period.
Mobility of Dicamba, Picloram and 2,4-D in Soil Columns
Authors: Grover R.
Published: January 2018

The movement of dicamba (3,6-dichloro-o-anisic acid), picloram (4-amino-3,5,6-trichloropicolinic acid), and 2,4-D [(2,4-dichlorophenoxy)acetic acid] was studied in five Canadian prairie soils using soil columns. The three acid herbicides showed the following general order of decreasing mobility in the five soils: Asquith sandy loam > Indian Head loam > Regina heavy clay > Weyburn Oxbow loam > Melfort loam, thus indicating an inverse relationship between adsorption and mobility. In general, the distribution coefficients (kd) were comparable to the corresponding Freundlich constants (k) and these were significantly related to the soil organic matter content, to a lesser extent to soil pH, and not correlated with soil clay content. The maximum concentrations of all three herbicides in the column effluents were well below their respective water solubilities and were inversely related to the distribution coefficients. The calculated values for the amounts of precipitation required to leach the three herbicides to a depth of 10 cm showed the following order of mobility: dicamba > picloram > 2,4-D.
Competition of Late-Emerging Weeds with Sugarbeets
Authors: Dawson J.H.
Published: January 2018

Weed-free sugarbeets [Beta vulgaris(L.) Beauv.] growing at a spacing of 60 cm (1/2 stand) yielded the same weight of roots as those spaced 30 cm (full stand), and those spaced 90 cm (1/3 stand) yielded about 90% as much. Gross sucrose yield was reduced somewhat more, because the larger roots growing in partial stands contained a lower percentage of sucrose than the roots in full stands. Annual weeds that emerged after July 1 were suppressed and. killed by competition from sugarbeets of normal vigor in a full stand, but became competitive when the sugarbeets were spaced at 1/2 or 1/3 of a full stand. Competition from barnyardgrass [Echinochloa crus-galli(L.) Beauv.] and pigweed (mixture ofAmaranthus retroflexusL. andA. powelliiS. Wats.), which reached a height of 150 cm, reduced root yields 5 to 39% in 1/2 stands and 19 to 49% in 1/3 stands, as compared with weed-free sugarbeets in the same stands. Hairy nightshade (Solarium sarachoidesSendt.) was abundant but never became taller than the sugarbeets. Its competition had no measurable effect on the sugarbeets.
Sorption, Movement, and Dissipation of Tebuthiuron in Soils
Authors: Chang S.S. , Stritzke J.F.
Published: January 2018

Adsorption of tebuthiuronN-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N’-dimethylurea appeared to be related to organic matter and clay content. After six successive desorption extractions, 40% of the tebuthiuron was adsorbed in soil with 4.8% organic matter but less than 1% was adsorbed in soil with 0.3% organic matter. Differences in adsorption were also reflected in the activity of tebuthiuron on soybeans [Glycine max(L.) Merr.] and corn (Zea maysL.) where it took 4.9 and 9.5 times as much tebuthiuron, respectively in soil with the greater adsorption to reduce growth by 50%. Soil mobility of tebuthiuron was identical to fluometuron[1,1-dimethyl-3-(α,α,α-trifluoro-m-tolyl),urea] in three soils tested. Soil mobility of herbicides was greater in soil with low organic matter and low clay content. Both temperature and soil moisture had an effect on persistence of tebuthiuron. Greater dissipation occurred at 15% soil moisture and 30 C than at lower moisture and temperature levels.
Response of Two Adenostoma Species to Several Herbicides
Authors: Radosevich S.R. , Graves W.L. , Agamalian H.A.
Published: January 2018

Single applications of several herbicides were compared after 12 to 48 months for control of chamise (Adenostoma fasciculatum H. & A.) and redshank chamise (Adenostoma sparsifolium Torr.). Glyphosate [N-(phosphonomethyl)glycine] provided more effective control and canopy reduction than any other herbicide tested. Triclopyr {[(3,5,6-trichloro-2-pyridinyl)oxy] acetic acid} and DX-1108 (ammonium ethyl carbanoylphosphonate) were also effective for control of chamise. Reduction in chamise canopy without leaf necrosis was observed with DPX-1108. Any herbicide tested could provide an alternative to currently used herbicides for chamise suppression.
Droplet Makeup and the Effect on Phytotoxicity of Glyphosate in Velvetleaf (Abutilon theophrasti)
Authors: Cranmer John R. , Linscott Dean L.
Published: January 2018

Velvetleaf was treated at the three and one-half leaf stage with one, three, or nine drops (1 μl each) of glyphosate and an amphoteric surfactant with the concentration of the droplets adjusted so that the total amount of active ingredient applied to each plant was constant. The phytotoxicity of glyphosate to velvetleaf was dependent on both the concentration of glyphosate and surfactant within the droplet A single concentrated droplet of glyphosate and surfactant was more effective in reducing the growth of velvetleaf than were more dilute droplets in greater number but with the same total quantity of herbicide. If the surfactant concentration was increased, the loss in efficacy was negated, provided the glyphosate concentration in the droplet was sufficiently high. Also, loss in efficiency was negated at increased glyphosate concentration and diluted surfactant level per droplet. The phytotoxic response of velvetleaf treated with one or three drops was greater at 45 than 90% relative humidity. This greater response at low relative humidity continued with increased surfactant concentration in each drop. However, the phytotoxic response was greater at 90 than 45% relative humidity when velvetleaf plants were treated with nine drops. When the surfactant concentration in each drop was increased, the plant's response at the two relative humidity levels did not differ.
Dissipation of Flurtamone in Three Georgia Soils
Authors: Mueller Thomas C. , Banks Philip A. , Bridges David C.
Published: January 2018

The dissipation of flurtamone was determined in three Georgia soils in 1987 to 1989. Flurtamone dissipation in soil was initially rapid but gradually slowed throughout the sampling interval. Dissipation was not affected by rate (0.8 or 1.7 kg ai ha-1) or application method (PPI or PRE). Dissipation rates were slightly more rapid in the Greenville and Dothan soils than in the Cecil soil, with calculated initial half-lives for each respective soil being 6 to 7, 8 to 10, and 9 to 23 days. There was no effect of previous flurtamone exposure on the dissipation rate in soil at any location.
Growth Response of Wheat (Triticum aestivum) Callus to Imazapyr and in Vitro Selection for Resistance
Authors: Heering David C. , Guenzi Arron C. , Peeper Thomas F. , Claypool P. L.
Published: January 2018

Intact wheat plants and wheat calli responded similarly to varying concentrations of imazapyr. Fifty percent growth inhibition of wheat callus occurred with 0.05 μM imazapyr after 70 d. As imazapyr concentration increased from 0 to 10 μM, the free isoleucine, leucine, and valine decreased from 160 to 35, 260 to 49, and 310 to 59 pmol mg−1, respectively. Resistant calli, which had relative growth rates exceeding a calculated upper prediction interval, were obtained by in vitro selection at 2 and 5 μM imazapyr. Resistant calli growing on 2 μM imazapyr had free isoleucine, leucine, and valine concentrations intermediate to the control and susceptible callus.
Dynamics of Yellow Starthistle (Centaurea solstitialis) Achenes in Field and Laboratory
Authors: Joley Donald B. , Maddox Donald M. , Supkoff David M. , Mayfield Aubrey
Published: January 2018

Studies were conducted to compare changes in germinability and/or viability of yellow starthistle achenes buried (in packets) in soil or stored dry in the laboratory, and to determine the rate of achene depletion from a soil seed bank. In one study, after 72 mo, 0 to 96% germinable achenes remained in packets buried 5 cm deep, and a mean above 99% after dry storage. In another study, total live (germinable plus viable) achenes declined from 100% at harvest to 77.6% after 24 mo of burial. Germinable pappus-bearing achenes remaining in packets increased with depth of burial. After 12 mo of burial, maximum survival of achenes occurred at depths of 5 cm or more. The density of yellow starthistle achenes and seedlings in a natural soil seed bank declined, when achene rain was prevented, to 3.9 and 1.1% of initial density, respectively, after 36 mo. Decline was attributed primarily to seedling emergence and achene death. Achene density in the upper 2.5 cm of soil appeared to be a good predictor of seedling emergence after autumn rains.
Population Dynamics and Control of Annual Weeds in Corn (Zea mays) as Influenced by Tillage Systems
Authors: Buhler Douglas D.
Published: January 2018

Field research was conducted at Hancock, WI, from 1985 through 1987 to evaluate effects of conventional tillage, chisel plow, ridge tillage, and no-tillage systems on population dynamics and control of annual weed species in corn grown continuously on a loamy sand soil without irrigation. In all years of the study, green foxtail densities were greater in chisel plow and no-tillage than in the conventional tillage system, while ridge tillage had densities lower than all other tillage systems. Common lambsquarters density in the chisel plow system reached nearly 500 plants m−2compared to less than 75 plants m−2in the other tillage systems when averaged over years. Average redroot pigweed densities in the no-tillage and chisel plow systems were 307 and 245 plants m−2compared to less than 25 plants m−2in the conventional and ridge tillage systems. Horseweed was observed only in no-tillage and ridge tillage plots. Green foxtail and redroot pigweed were more difficult to control in chisel plow and no-tillage than in the conventional and ridge tillage systems with several herbicide treatments. Corn yields were not affected by tillage systems under weed-free conditions. Corn yield differences among tillage systems when the same herbicide treatment was applied appeared to be due to differences in weed control.
Herbicide Programs in No-Tillage and Conventional-Tillage Soybeans (Glycine max) Double Cropped After Wheat (Triticum aestivum)
Authors: Sims Barry D. , Guethle David R.
Published: January 2018

Postemergence and commonly used preemergence plus postemergence herbicide programs were evaluated for weed control in conventional and no-tillage soybeans double cropped after winter wheat in the northern Mississippi River Delta. Broadleaf weed species present varied with tillage, location, and year. Large crabgrass was present in both tillage systems for all locations and years. Conventional tillage usually resulted in higher densities of large crabgrass, common cocklebur, and smooth pigweed. Soil-applied preemergence herbicides alone did not provide season-long ivyleaf and entireleaf morningglory or common cocklebur control in either tillage system. For weed control and soybean yields comparable to weed-free controls, postemergence broadleaf herbicides were required in both tillage systems following the soil-applied herbicide programs, alachlor plus linuron and alachlor plus metribuzin. Postemergence herbicide programs provided excellent season-long annual grass and broadleaf weed control when sethoxydim was applied separately from the broadleaf herbicides. Antagonism of large crabgrass control resulted when sethoxydim was tank mixed with postemergence broadleaf herbicides, compared to separate applications of the postemergence grass and broadleaf herbicides. In three out of four studies, soybean yields in handweeded controls were similar between tillage systems.
Photoperiod Responses in Monoecious and DioeciousHydrilla verticillata
Authors: Spencer David F. , Anderson Lars W.J.
Published: January 2018

Thirty-eight percent of monoecious hydrilla [Hydrilla verticillata(L.f.) Royle # HYLLI] grown from tubers produced new tubers after 28 days exposure to a 10-h photoperiod. One hundred percent of the plants grown at a 10-h photoperiod produced tubers by 56 days while only thirty-eight percent of those grown at a 12-h photoperiod did so. Plants grown at 14- or 16-h photoperiods did not produce tubers. Tubers appeared to be produced at the expense of new root and shoot tissue. Dioecious hydrilla (female) grown under similar conditions did not produce tubers by 56 days at any photoperiod examined. Relative growth rates (total dry weight) for both types did not differ with photoperiod and ranged between 81 ± 63 and 284 ± 52 mg·g-1·wk-1(regression coefficient ± standard error; n = 30). In general, total chlorophyll (a+b) was greater for dioecious than for monoecious plants. The ratios of chlorophyll “a” to chlorophyll “b” and carotenoids to chlorophyll a changed with increasing photoperiod and plant age in a similar manner for both monoecious and dioecious plants.
Persistence of Norflurazon in Five Georgia Soils
Authors: Schroeder Jill , Banks Philip A.
Published: January 2018

Norflurazon [4-chloro-5-(methylamino)-2-(3-(trifluoromethyl)phenyl)-3(2H)-pyridazinone] persistence in five Georgia soils after application to the same plots in 1982 and 1983 was characterized by rapid initial degradation followed by slow loss of the herbicide. The rate of norflurazon loss at each location for each year was not affected by application rate (1.7 or 3.4 kg ai/ha). Relative rates of norflurazon loss were Dothan loamy sand ≥ Greenville sandy clay loam ≥ Rome gravelly clay loam = Appling coarse sanely loam > Bradson clay loam. The rate of dissipation was slower in 1983 than 1982 in the Greenville and Appling soils. Cool and/or dry environmental conditions combined with higher soil organic matter content caused slower herbicide loss. Norflurazon residue 1 yr after treatment in all soils was greater in 1983 than in 1982. Significant injury to grain sorghum [Sorghum bicolor(L.) Moench. ‘BR 64’) was observed in the spring of 1984 at all locations in all plots that were treated with norflurazon for the previous two seasons. The degree of injury corresponded to the concentration of norflurazon detected at that sampling date. Leaching did not appear to be an important method of norflurazon loss.
Persistence and Activity of Norflurazon and Fluridone in Five Georgia Soils Under Controlled Conditions
Authors: Schroeder Jill , Banks Philip A.
Published: January 2018

Response of grain sorghum [Sorghum bicolor(L.) Moench. ‘BR 64’] to norflurazon [4-chloro-5-(methylamino)-2-(3-(trifluoromethyl)phenyl)-3(2H)-pyridazinone] and fluridone {1-methyl-3-phenyl-5-[3-(trifluoromethyl) phenyl]-4(1H)pyridinone} and the effect of previous treatment on the persistence of herbicide activity in five soils were determined in the greenhouse. Relative phytotoxicity of fluridone in the soils was ordered as Greenville sandy clay loam > Appling coarse sandy loam > Dothan loamy sand = Rome gravelly clay loam > Bradson clay loam. Phytotoxicity of norflurazon was ordered as Greenville = Appling = Dothan > Rome > Bradson. Fluridone was more phytotoxic than norflurazon. Field soil that has been previously treated with norflurazon or fluridone (500 days earlier at 1.7 kg ai/ha) still had low concentrations of each herbicide present at the time of retreatment in the greenhouse. Previous treatment of norflurazon did not affect the rate of decline in activity in any of the soils compared to previously nontreated soils except for Appling. Significantly higher concentrations of norflurazon remained in all previously treated soils 297 days after treatment (DAT) compared to previously nontreated soil. Residual carryover of norflurazon was greater in the Bradson soil (2.8% O.M.) than soils having less than 2% O.M. Fluridone dissipation was significantly faster in previously treated soil than in previously nontreated soil, indicating enhanced microbial degradation of the herbicide.
Modelling reversible execution of robotic assembly
Authors: Laursen Johan Sund , Ellekilde Lars-Peter , Schultz Ulrik Pagh
Published: January 2018

Programming robotic assembly for industrial small-batch production is challenging; hence, it is vital to increase robustness and reduce development effort in order to achieve flexible robotic automation. A human who has made an assembly error will often simply undo the process until the error is undone and then restart the assembly. Conceptually, robots could do the same. This paper introduces a programming model that enables robot assembly programs to be executed in reverse. We investigate the challenges in running robot programs backwards and present a classification of reversibility characteristics. We demonstrate how temporarily switching the direction of program execution can be an efficient error recovery mechanism. Moreover, we demonstrate additional benefits arising from supporting reversibility in an assembly language, such as increased code reuse and automatically derived disassembly sequences. As a default approach to reversibility, we use program inversion and statement-level inversion of commands, but with a novel override option providing alternative sequences for asymmetric reverse actions. To efficiently program for this model, this paper introduces a new domain-specific language, SCP-RASQ (Simple C++ Reversible Assembly SeQuences). In initial experiments, where 200 consecutive assemblies of two industrial cases were performed, 18 of 22 errors were corrected automatically using only the trial-and-error capabilities that come from reverse execution.
Effects of Ensilage and Silage Fermentation Pattern on the Intake and Performance of Lactating Dairy Cows
Authors: Cushnahan A , Mayne C S
Published: January 2018

It is generally acknowledged that lactating dairy cows offered grass silage consume less dry matter (DM) and produce less milk with a lower protein concentration than cows offered fresh pasture. However, there is little evidence to indicate whether these effects are due to the influence of ensiling per se or to differences in herbage composition. The aims of the current experiment were to evaluate the effects of ensiling per se and silage fermentation pattern on forage intake and dairy cow performance.

A perennial ryegrass sward (Lolium perenne cvs Barlenna and Talbot) was divided into 4 areas (A, B, C and D) comprising one area of 6.7 ha (area A) and three areas of 0.7 ha (areas B, C and D). Each area received a total of 361 kg N, 74 kg P2O5 and 144 kg K2O/ha over the season. From 1 June 1993, herbage was harvested once daily from areas B, C and D using a double chop forage harvester and offered to dairy cows housed indoors during weeks 1, 2 and 3 respectively (Treatment G).
Selection for components of efficient lean growth in Large White pigs
Authors: Cameron N.D.
Published: January 2018

An experiment was started in 1984 at Edinburgh and Wye to study responses to divergent selection for lean growth rate (LGA), lean food conversion ratio (LFC) and daily food intake (DFI). This paper measured the selection pressure applied, the responses in the selection criteria and estimated the genetic and phenotypic relationships between the selection criteria with ad-libitum feeding of Large White pigs after four generations of selection.

Selection objectives and criteria. The LGA (LFC) selection objective was to obtain equal correlated responses in growth rate (food conversion ratio) and carcass lean content, measured in phenotypic s.d. The LGA, LFC and DFI selection criteria had phenotypic s.d. of 27, 29 and 250 units and results are presented in s.d. units.
Responses in performance test traits to selection on components of efficient lean growth
Authors: Cameron N.D. , Curran M.K.
Published: January 2018

This study determined the responses in performance test traits after four generations of divergent selection for lean growth rate (LGA), lean food conversion ratio (LFC) and daily food intake (DFI) in Large White and Landrace pigs.

Within each of the three selection groups, there were high and low selection lines with a control line, each consisting of 10 sires and 20 dams, with an average of 3 boars and 3 gilts tested per litter. A total of 3537 Large White and 2642 Landrace pigs were performance tested in Edinburgh and Wye, respectively. The performance test was over a fixed weight range of 30±3 kg to 85±5 kg. All pigs were individually penned, with ad-libitum feeding of a high energy (13.8 MJ DE/kg DM) and high protein (210 g/kg DM crude protein) pelleted ration.

Correlated responses in performance test traits to selection on LGA, LFC and DFI were estimated from the mean within-generation selection line breeding values for each trait, determined with the additive genetic and common environmental (co)variances for performance test traits, which were estimated using multivariate derivative-free residual maximum likelihood analyses.
Reproductive performance of pigs selected for components of efficient lean growth
Authors: Kerr J. C. , Cameron N. D.
Published: January 2018

This study determined the correlated responses in reproductive performance after five generations of divergent selection for components of efficient lean growth rate in Large White pigs.

Data were collected from five generations of pigs divergently selected for daily food intake (DFI), lean food conversion (LFC), lean growth rate on ad-libitum feeding (LGA) and lean growth rate on restricted or scale feeding (LGS). In each selection group, there were high, low and control lines, each consisting of 10 boars and 20 gilts. Animals were mated at around 9.5 months of age. Pregnant gilts were fed 2.5 kg daily and farrowed sows up to 3.5 kg twice daily of a 160 g/kg DM crude protein and 132 MJ/kg DM digestible energy ration. Animals were farrowed at 414 (s.d. 19.7) days of age, on average. No cross fostering was practised. Piglets were offered creep feed containing 235 g/kg DM crude protein and 160 MJ/kg DM digestible energy from 14 days and were weaned at an average of 35 (s.d. 3) days. Litter traits were measured on 1220 selected Large White gilts, with 13030 piglet birth weights and 9951 weaning weights.
Preselection of pigs for performance testing
Authors: Grundy B.
Published: January 2018

An important aspect of animal improvement is the correct identification of those individuals with superior genetic merit. Testing to accurately assess merit, however, can be a costly component of improvement. In the Group Nucleus there is a substantial number of potential offspring to be tested even within a system where the farrowing and testing is practised continuously throughout the year. In order, therefore, to reduce costs it could be beneficial to accurately predict genetic worth prior to test on either mean parental breeding value or a trait expressed early before test.

A Group Nucleus population was modelled by stochastic simulation with selection at two stages The model for the trait(s) selected comprised animal, common environment, herd-year-season and error components. A multivariate animal model BLUP routine was used for the evaluation.
Effects of Performance Testing on Superovulatory Response in Juvenile Simmental Heifers
Authors: Tregaskes L.D. , Broadbent P.J. , Roden J.A.
Published: January 2018

Multiple ovulation and embryo transfer (MOET) is being used by the Scottish Agricultural College, Aberdeen to accelerate genetic change in the Simmental breed. The selection goal of the project is improving the efficiency of lean meat production. The factors in this goal are saleable meat (predicted from liveweight, fat depth and muscling score), food intake and calving difficulty (predicted from gestation length and birth weight). Success of the project depends on the generation of sufficient grade 1 embryos from selected donor heifers in a 12 week period following a performance test. Performance testing to assess beef characteristics can produce precociously fat heifers which may be detrimental to embryo production. The onset of puberty in heifers is also highly variable and influenced by many factors including body weight and nutrition. The objective of this study was to examine the relationship of superovulatory response to performance on test and age at the onset of puberty.
Effect of enzyme supplementation on intestinal parameters in the pig
Authors: Inborr J. , Bedford M. , Graham H.
Published: January 2018

Reducing foregut digesta viscosity is the primary mode of action of feed enzymes in improving performance in broilers fed wheat and barley based diets (Bedford & Classen, 1991, Graham et al, 1992). In pigs, inclusion of appropriate fibre-degrading enzymes can improve the apparent digestion of nutrients in the small intestine (Graham et al, 1988). This has been attributed to both reduced digesta viscosity and an opening up of the feed cell walls enclosing the nutrients. However, the exact mechanism of this effect is unknown. This trial was designed to investigate the influence of enzyme supplementation on gut parameters in the pig.

A total of 40 crossbred pigs were weaned at about 9.5 kg and placed into 5 blocks of 8 individual metabolism cages based on litter origin, sex and liveweight. There were 2 treatment replicates per block. The mash diets were based on barley (751 kg/t), soyabean meal (150 kg/t), fish meal (40 kg/t) and soya oil (20 kg/t), with 1 kg/t chromic oxide as a marker. A hulled, low β-glucan (2.9 % of DM; Arra, Finland) and a naked, high β-glucan (5.3 % of DM; Condor, Canada) barley were used, and diets were fed without or with added /3-glucanase. Pigs were fed for 21 days, then sacrificed. Digesta was collected from the stomach, 4 equal lengths of the small intestine, the caecum and 2 equal sections of the colon plus rectum.
The Influence of Genetic Merit For Milk Production on the Response to Complete Diet Feeding
Authors: Patterson D.C. , Gordon F.J. , Mayne C.S.
Published: January 2018

In two previous studies at this Institute, premixing of the silage and concentrate elements of the diet prior to feeding (complete diet feeding) produced either no increase in intake and milk production (Agnew and Mayne, 1992) or a slight increase in intake with no response in milk production (Agnew and Mayne, 1990). However the maximum proportions of concentrate dry matter intake (DMI) in the diets used in these experiments were 0.54 and 0.51 respectively. With the present rapid increases in cow genetic merit, across the industry, coupled with possible changes in the relative costs of feed grains and ensiled grass, there is a need to explore the response to complete diet feeding with animals of high genetic merit receiving higher proportions of concentrates. The current study therefore examined the response to complete diet feeding and its interaction with genetic merit of the cow, when using high concentrate diets.
The Effect of Processing Technology on Feed Content of Vitamin A and its Retention in the Livers of Broiler Chicks
Authors: Kenny M S , Williams P E V , Overend M A , Scaife J R
Published: January 2018

Modem feed processing techniques, designed to reduce the microbial burden of compounded animal feedstuffs, subject feed ingredients to high temperatures and pressures. Certain feed components are labile under these conditions and may be destroyed or undergo chemical modification during processing reducing their availability. A number of vitamins, added as supplements to diets, are known to be sensitive to aggressive processing methods. Vitamin A is particularly sensitive to oxidation and losses are increased in the presence of high humidity and temperature. A study was carried out to examine the effects of two processing technologies, the Anaerobic Pasturisation Conditioner (APC) and the Expander (EX), upon the content and bioavailability of vitamin A in poultry diets.
The effect of rumen pH or osmolality upon the diet selections made by sheep
Authors: Cooper S. D. B. , Kyriazakis I , Nolan J. V. , Anderson D. H. , Oldham J. D.
Published: January 2018

We have shown previously (Cooper and Kyriazakis, 1993) that lambs offered a choice between a low energy density (ED) food and a high ED food, do not solely consume the high ED food, as it would have been expected from an optimal foraging perspective. It is proposed that the lambs offered this choice have to balance the benefits of consuming a high ED food (high growth rate) against the metabolic costs incurred, which may be excessive disturbances to the rumen environment, such as a low rumen pH and an increased osmolality (this has been shown to be the case in the diet selection of sheep between concentrates and hay in an experiment by Engku Azahan and Forbes (1992)). The aim of this experiment was to test which of these two rumen conditions have an influence upon diet selections made by sheep offered foods of different ED.
Factors affecting the prediction of organic matter Digestibility of grass silage by near infrared reflectance spectroscopy
Authors: Deaville E. R. , Givens D. L
Published: January 2018

Earlier studies (Barber et al., 1990) showed the superiority of near infrared reflectance spectroscopy (NIRS) for predicting the organic matter digestibility (OMD) in vivo of grass silage over fibre and in vitro procedures. However, during routine application occasional erroneous values were predicted for which there were no obvious reasons. Baker and Barnes (1990) reported that the likely sources of the problems contributing to the errors were instrumental and environmental noise, sample particle size effects and variable moisture content of the samples. These authors also reported that standard normal variate - detrend (SNV-D) scatter correction procedure of Barnes et al. (1989) could be used to reduce the effects of particle size variation and they also emphasised the need to test NIRS calibrations for repeatability. The purpose of the present work was to evaluate the use of the SNV-D scatter correction procedure, the techniques for reducing the sensitivity of calibrations to residual moisture and methods to improve the repeatability of the predicted OMD in vivo values of grass silage. In addition, a further objective was to compare three calibration methods, namely modified stepwise regression (MSR), modified partial least squares (MPLS) and principal component analysis (PCA).
Observations on the stability of rumen metabolism and their implications for experimental design
Authors: Huntington J.A. , Offer N.W.
Published: January 2018

The rumen in situ technique has been adopted as the standard method (AFRC, 1992) for the characterisation of nitrogen in feedstuffs for ruminants. Differences in the degradation characteristics of identical samples both within and between laboratories have been observed (Madsen and Hvelplund, 1985; Oldham, 1987; Kandylis and Nikokyris, 1991). These variations may relate to a number of variables including, cloth type, weave, pore size, sample preparation, basal diet of host and post-incubation washing procedure. Another of the possible causes of variation between similar measurements may be dynamic changes in rumen metabolism. Wilson and Briggs (1955) observed that the day-to-day variation in viable bacterial counts in animals fed a fixed diet was even greater than those observed with gross changes in basal diet. The aim of the present experiment was to observe the day-to-day variation in the rumen of sheep fed a constant diet over 18 weeks.
Total phenols and protein precipitation assays as indicators of the inhibitory effects of phenols on rumen micro-organisms
Authors: Wood C D , Plumb V E
Published: January 2018

Phenolics, such as tannins, have been implicated as inhibitors of digestibility. A wide range of assays for measuring phenols have been proposed (reviewed by Hagerman and Butler, 1989) but there is little experimental evidence to indicate which are most appropriate for assessing nutritive value. The objective of this study was to investigate correlations between phenol assays and the effects of phenolics on in vitro fermentation by rumen micro-organisms to identify which assays most reliably indicated the extent of these effects.

Extracts were prepared from 12 Bolivian tree leaf samples using 70% aqueous acetone (500mg dried sample extracted with 5 ml solvent) and analysed for total phenols (TP) by the Prussian Blue method (Price and Butler, 1977), protein precipitation activity (PPA) by a radial diffusion technique (Hagerman, 1987) and condensed tannins (CT) by acid butanol (Porter et al, 1986). The samples used are listed in Table 1.
The Ability of Polyethylene Glycol to Enhance the Digestion of Tropical Forage Legumes of Varying Tannin Content
Authors: Longland A.C. , Theodorou M.K. , Listerl S.J. , Morris P. , Gill M.
Published: January 2018

Condensed tannins have been implicated in reducing the nutritive value of potentially important feedstuffs, largely through reducing protein and fibre digestion. Tannins can mediate their effects directly by binding to the protein or fibre fraction rendering them resistant to digestion, or indirectly by binding with digestive enzymes, preventing their catalytic action. These adverse effects of tannins, however, can be mitigated by the use of agents such as polyethylene glycol (PEG) which form complexes with condensed tannins rendering them less effective as protein and fibre-binding agents. In this study, the effects of polyethylene glycol on (a) the in vitro fermentability and (b) the digestibility of the fibre fraction (= non-starch polysaccharide; NSP) of leaves of six tropical forage legumes varying in condensed tannin content was investigated.

The species used, chosen for their varying tannin contents, were Sesbania goetzei (SG), S. seban (SS), Leucaena leucocephala (LL), Dioclea guianensis (DG) Calliandra sp. (C) and Tadehagi sp. (T23).
The effect of exogenous melatonin and the plane of nutrition after weaning on ovulation rate in salz ewes lambing in the seasonal anoestrus
Authors: Zarazaga L. , Forcada F. , Abecia J.A. , Mozota J.
Published: January 2018

Induction of oestrus and pregnancy in the seasonal anoestrus permits lambing during the breeding season and mating in a short period of time after weaning, but after spring lambing postpartum anoestrus is longer than it is in autumn lambing, and no breeds are able to resume cyclic activity two months after lambing. Nutrient status has been shown to be a major factor affecting the onset of ovarian cyclicity in postpartum ewes. On the other hand, melatonin implants were demonstrated to be efficient in advancing the annual breeding season, but the efficiency of this treatment could be modified by the nutritional status of the animals. The aim of this experiment was to determine the effect of exogenous melatonin, connected with the plane of nutrition after weaning, on the resumption of sexual activity and ovulation rate (OR) in a synthetic Spanish sheep breed lambing in spring.
Response of autumn calving suckler cows to the feed additive Avotan
Authors: Lowman B G , Scott N A , Mudd A J
Published: January 2018

Avotan is a feed additive commonly used in finishing and growing beef cattle systems to improve feed efficiency - producing higher liveweight gains on similar feed intakes. The active ingredient is a glycopeptide antibiotic (Avoparcin, Cyanamid UK) active against Gram - positive bacteria. In 1991 Avotan received an EEC product licence for use in dairy cows. Extensive trials showed that on average Avotan gave a 5% response in milk yield on the same level of feed intake with no effect on milk composition. No information was however available on the use of Avotan in beef cows. This trial reports on the response of autumn calving suckler cows to Avotan in terms of both cow and calf liveweight change and cow fertility.
Use of Fresh or Frozen Cow Faeces Instead of Sheep Rumen Liquor to Provide Mocroorganisms for in Vitro Digestiblity Assays of Forages
Authors: Akhter S , Owen E , Fall A , O'Donovan F , Theodorou M K
Published: January 2018

Current techniques for in vitro digestion of forages depend on the use of rumen fistulated animals to supply microbial suspensions in rumen liquor. The objective of the present study is to develop a noninvasive alternative to rumen liquor as a source of micro-organisms in the two-stage, in vitro digestion technique of Tilley and Terry (1963).

EL Shaer, Omed, Chamberlain and Axford (1987) showed a high correlation between digestibility in vitro determined using micro-organisms from rumen liquor and from freshly-voided sheep faeces. The disadvantages of using sheep faeces are (a) the need for fresh faeces, (b) the small quantities voided at any given time and (c) the difficulty of enticing sheep to defaecate at a specific time.

Cow faeces as a source of micro-organisms was investigated in the present study because of the ease of collecting a large quantity of freshly-voided faeces at a given time. Another objective of the present study was to investigate whether faeces could be frozen and stored for future use as a source of micro-organisms for the in vitro digestibility assay. A further objective was to investigate whether rumen liquor could be frozen and stored for future use.
Differentiation of Yeast Cultures in Ruminant Feedingstuffs Using a Rapid DNA Fingerprinting Technique
Authors: Moore Elizabeth , Headon Denis R.
Published: January 2018

Research indicates that certain yeast strains are beneficial in their capacity to stimulate key microbial populations. This stimulation is strain specific with similar yeast strains exerting their effect on totally different microbial populations. Future yeast culture supplements may contain mixtures of different strains designed to suit specific diets. This, therefore, requires the development of a rapid sensitive technique to differentiate among taxonomically similar yeast strains in animal diets. This technique, termed the Randomly Amplified Polymorphic DNA (RAPD) assay, is based upon the use of randomly designed short polynucleotide primers to amplify genetic sequences from the DNA of the desired yeast strain. Our objective involves the development of this technique to distinguish between closely related yeast strains present in feed. The feed sample investigated was a standard cattle ration containing three strains of Saccharomyces cerevisiae (1026, 2045 and 2020) and Candida utilis 3001 at a concentration of 106 CFU/g respectively. Isolation of single colonies of yeast strains present was achieved by feed extraction in dilution buffer followed by plating a series of dilutions on rose-bengal agar. Thirty randomly selected colonies were cultured in YPD (1% yeast extract, 2% peptone, 2% glucose) broth for 24 - 30 hours at 30°C. Genomic DNA was isolated from yeast cells by standard methods based on subjection of the cells to vortex mixing in the presence of glass beads, triton X-100, sodium dodecyl sulphate, phenol and chloroform. Isolated DNA from randomly selected colonies was amplified by Polymerase Chain Reaction (PCR) for 45 cycles of 1 min at 94°C, 1 min at 36°C and 1 min at 72°C using randomly designed 10 bp primers.
Predicting the voluntary intake of barley straw with near infrared reflectance spectroscopy (NIRS)
Authors: Goodchild A V , Jaby El-Haramein F , Treacher T T
Published: January 2018

In developing countries, straws, stovers and stubbles provide a large proportion of the nutrient intake of ruminants. Cereal breeders working for these countries need a rapid test to predict the nutritional value of straw. An important component of nutritional value of straw is voluntary intake (Goodchild et al. 1992). Voluntary intake (DMT) is usually measured in samples of straw weighing 100 kg or more: in contrast, only a few plants weighing tens of grams are available for each genotype in the early stages of breeding. Indirect methods of estimating voluntary intake, like in vitro gas production, are available but relatively costly. For these reasons, and because selecting for grain yield and stem stiffness has been a priority in developed countries, breeders have tended to ignore straw quality.
A comparison of whole crop fodder beet atand grass silages when fed to Ewes in late pregnancy
Authors: Whittle C.T. , O'Doherty J.V. , Crosby T.F.
Published: January 2018

Whole crop fodder beet silage is a highly nutritious feed for both cattle and sheep. It is also considered that the addition of an absorbent further enhances both the feeding value and its palatability. The objective of this experiment was to compare the nutritive value of two types of whole crop fodder beet silage with that of grass silage when fed to ewes in late pregnancy.

Twenty two oestrus synchronised, twin bearing, mature ewes (2-7 yrs) of mixed lowland breeds were selected for the trial. They were housed on December 17th, approximately 10 weeks prior to their expected mean lambing date. Following pregnancy scanning, the ewes were allocated to their respective treatment groups. Each of the three treatment groups were balanced for breed, age and live weight. The ewes were individually penned with peat moss as the bedding material.
A comparison of grass silage and whole crop fodder beet Silage when fed to sheep.
Authors: O'Doherty J.V. , Callan J.J. , Quinn P.J. , Crosby T.F.
Published: January 2018

The use of fodder beet in diets fed to cattle and sheep has always been valued highly. Recent long-term experiments have shown that the palatability and high feeding value of fodder beet is fully preserved during the ensiling process. The objective of this experiment was to compare the nutritive value of whole crop fodder beet silage with that of grass silage when fed to sheep.

The grass silage was harvested from a primary growth of perennial ryegrass, which had a dry matter (DM),water soluble carbohydrate and crude protein contents of 191,137, and 53 g/kg DM respectively on 30/31 May following a 12 hour wilt and had 2.5 litres of formic acid applied in the field via the forage harvester. The whole crop fodder beet (var. Amigo, DM 155 g/kg; CP. 65 g/kg DM) was harvested on 30 October using a whole crop harvester. Eight cheviot cross castrated male sheep weighing on average 47 kg were randomly allocated to the two silage treatments, and then housed in metabolism cages fitted with urine and faeces separators. The trial consisted of an initial 10 day acclimatisation period and a further 10 days during which feed intake, faeces and urinary output were recorded.
The effects of ensiling molassed sugar beet pulp with grass and protein supplementation on pregnant ewe performance.
Authors: O'Doherty J.V. , Crosby T.F. , Quinn P.J.
Published: January 2018

There is increasing interest in the addition of dry feed materials to grass at ensiling, primarily as a means of reducing effluent production although other benefits claimed include improvements in silage fermentation and animal performance. The objective of the present study was to examine the possible use of molassed sugar beet pulp fed either separately or ensiled with grass at the time of silage making on ewe and lamb performance, and with or without protein supplementation.

Grass from a primary growth of perennial ryegrass with dry matter, water soluble carbohydrate and crude protein contents of 13.2%, 24 g/kg and 106 g/kg DM respectively was mowed on June 2nd and was picked up using a precision chop harvester on the 4th and 5th of June. The weather during this period was extremely unfavourable for good silage making. There were 7.5, 1.5 and 2.8 mm of rainfall on the 3rd, 4th and 5th of June. The temperatures (0 C) on these days were: 2nd June - 12.9: 3rd -10.6: 4th - 10.7. There was no bright sunshine hours on either the 3rd or 5th of June and only 2.1 hours on June 4th. Two treatments were imposed (i) formic acid (2.5 litres/t) applied in the field via the forage harvester (GS) (ii) molassed sugar beet pulp (MSBP)(50 kg/t) applied by hand in the silo on top of each load of grass(GSP).The two silos were filled .consolidated and sealed within 24 hours.
Methane production in cattle and sheep fed grass silage plus a barley based concentrate
Authors: Newbold C.J. , Moss A.R. , Mollinson G.S.
Published: January 2018

Increasing concern over the role of greenhouse gases in global warming has lead to a renewed interest in the production of methane by ruminants. Sheep are routinely used to study digestibility, however their use as a model to study methane production by cattle has received only limited attention (Blaxter and Wainman, 1964). The objective of the current study was to establish whether differences in methane production exist between sheep and cattle and to measure the magnitude of these differences under various dietary situations.