bluuebunny/crossref_metadata_2025 huggingface dataset:
EFFECT OF GROWTH HORMONE-RELEASING FACTOR (1–44)NH2 ADMINISTRATION ON SOMATOTROPIN IN PIGS
Authors: JOHNSON J. L. , COFFEY M. T. , ESBENSHADE K. L. , SCHRICKER B. R.
Published: March 2010

Two experiments were conducted to examine the dose response and optimum pattern of subcutaneous (s.c.) administration of human growth hormone-releasing factor [hGRF (1–44)NH2]on serum somatotropin (ST) in barrows. In exp. 1, 10 barrows (79.9 ± 3.3 kg) were used in a replicated 5 × 5 Latin square and blood samples were collected for 300 min from a single injection of hGRF. Injecting 0, 1, 10, 40 or 100 μg hGRF kg−1 resulted in dose related increase (P < 0.01) in peak concentrations of pST (3.93, 4.41, 10.61, 16.01 and 23.56 ng mL−1), and area under the ST response curve (AUC) (565.4, 546.2, 757.5, 1048.0 and 1314.0 ng min mL−1, respectively). The 40 μg kg−1 dose resulted in a higher (P < 0.05) peak pST and AUC than 0 or 1 μg hGRF kg−1. Peak concentration and AUC were greater (P < 0.05) for the 100 μg hGRF kg−1 dose compared with the 0, 1 and 10 μg hGRF kg−1 doses, but there was no difference between the 40 and 100 μg kg−1 doses. In exp. 2, eight barrows (85.4 ± 8.0 kg) were used in a replicated 4 × 4 Latin square to examine the relationship between pattern of hGRF administration and serum ST. Blood samples were collected −15, 0 and 15 min from initiation of administration and then hourly for 24 h. Treatments were designed to deliver 160 μg hGRF kg−1 every 24 h and were administered as 40 μg kg−1 injected four times daily, 80 μg kg−1 injected twice daily or by continuous s.c. infusion. There was no difference (P > 0.10) between treatments for peak ST concentration, AUC or area above the ST baseline. These data indicated a dose response to s.c. hGRF injections and ST in barrows. Further, ST response was not altered by the pattern of s.c. administration when barrows received 160 μg hGRF kg−1 daily by either 4 or 2 discrete injections or by continuous infusion. Key words: Swine, somatotropin, growth hormone-releasing factor
THE EFFECT OF THE ALPHA ADRENERGIC AGONIST CLONIDINE ON THE GROWTH, CARCASS YIELD, MEAT QUALITY AND PHYSIOLOGICAL-ENDOCRINOLOGICAL RESPONSE IN STEERS
Authors: SCHAEFER A. L. , JONES S. D. M. , TONG A. K. W. , KENNEDY A. D. , ONISCHUK L. A.
Published: March 2010

A pilot trial with the alpha-2 agonist clonidine hydrochloride, administered as a feed additive at three levels to crossbred steers (427 kg), was conducted to examine the effectiveness of this class of products as a repartitioning agent. The steers, averaging 427 kg, were divided into four treatment groups of eight animals each, and were individually fed to appetite a balanced diet to which clonidine had been added at levels of 0.0 (C), 1.0 (H), 0.5 (M), or 0.25 (L) g kg body weight−1 d−1. From venous blood samples collected after approximately 12 wk of feeding clonidine, treatments H and M increased serum glucose levels (P ≤ 0.05) by up to 50% above controls (C). In addition, compared to the control steers, the high clonidine dose raised the serum insulin values within 5 h of consuming clonidine (P ≤ 0.03). However, this change was not observed in either the M or L groups. Heart weights increased by up to 15% (P ≤ 0.07) in the H, M and L treatments compared to treatment C. In contrast, at doses of 0.25–1.0 g kg−1 orally administered clonidine displayed little or no consistent carcass repartitioning effect in steers. Key words: Beef cattle, clonidine, physiology, carcass yield
EFFECT OF SUDDEN LOSS OF CALCIUM FROM THE EXCHANGEABLE CALCIUM POOL ON BONE CALCIUM RESORPTION IN MATURE SHEEP
Authors: FREDEEN A. H. , KESSEL J. S. VAN
Published: March 2010

Two groups of three mature, nonlactating, nonpregnant ewes were used to assess the capabilities of sheep to meet their metabolic Ca requirements when fed recommended levels of Ca and confronted with a sudden Ca loss. Irreversible Ca loss was established at 1 g Ca d−1 in three ewes via continuous infusion of an isotonic solution of ethylene glycol-bis (β-amino ethyl ether) N,N,N1,N1- tetraacetic acid (EGTA). Calcium absorption and metabolism were monitored using a radiodilution technique in which a four-compartment model of Ca metabolism was fit to plasma Ca specific activity decay and urinary and fecal radiocalcium excretion data. All ewes exhibited positive Ca balance (averaging 1.34 g d−1). Efficiency of dietary Ca absorption (averaging 46%) approached maximum, indicating that level of dietary Ca used in this trial was near requirement. Bone Ca resorption increased (P < 0.05) in infused sheep (1.82 g d−1) compared to controls (− 1.38 g d−1) while rate of Ca absorption showed a nonsignificant change (1.80 and 1.94 g d−1 in control and infused ewes, respectively). Key words: Calcium, absorption, metabolism, sheep, requirement
INTAKE AND DIGESTIBILITY IN STEERS FED GRASS HAY SUPPLEMENTED WITH CORN OR BARLEY AND FISH MEAL OR SOYBEAN MEAL
Authors: SEOANE J. R. , CHRISTEN A.-M. , DION S.
Published: March 2010

Twenty crossbred steers (493 ± 6 kg) were used to study the effects of two types of cereal (cracked corn or rolled barley) and two protein supplements (fish meal or soybean meal) on voluntary intake and apparent digestibility of grass hay based diets for beef steers. Diets contained 65% concentrate and 35% roughage as fed. Daily digestible energy intake, expressed as MJ kg−0.75 body weight, was 15% higher in steers fed barley (P < 0.01) and 10% higher when fish meal was fed instead of soybean meal (P < 0.04). Apparent digestion coefficients of DM and acid detergent fiber were similar for the four diets. Apparent protein digestibility was 30.5% higher in steers receiving barley (P < 0.01). Energy digestibility was slightly higher (6.5%, P < 0.14) for animals receiving barley compared with those receiving corn, probably because digestibility of barley starch was 7.3% higher (P < 0.01). Thus, digestible energy values of barley diets were 6.3% higher than those of corn diets. The results suggest that rolled barley was superior to cracked corn and fish meal superior to soybean meal when fed with grass hay to steers. Key words: Cattle, fish meal, soybean meal, corn, barley
CHANGES IN APPARENT ABSORPTION AND RETENTION OF NUTRIENTS DURING GESTATION IN GILTS FED TWO DIETARY CALCIUM-PHOSPHORUS LEVELS
Authors: GRANDHI R. R. , IBRAHIM E. A.
Published: March 2010

Twenty-seven Landrace × Yorkshire gilts were used in three trials to determine the influence of feeding more Ca-P from breeding through gestation on changes in apparent absorption and retention of energy, nitrogen, Ca, P, Mg, K, Mn, Cu and Zn, at the 5th, 8th, 11th, 13th and 15th wk of gestation. The gilts were housed during gestation in individual sow metabolism stalls equipped for separate collection of feces and urine. In trial 1, feeding more Ca-P (26.2–23.8 vs. 21.2–15.4 g d−1) during gestation reduced (P < 0.05) the percent absorption and retention of Ca, Mg, Zn and Cu at certain stages of gestation but the overall differences between the two diets were not significant. In trial 2 feeding more Ca-P (26.8–15.8 vs. 20.4–10.4 g d−1) also reduced the percent absorption and retention of Ca, Mg, Zn and Cu at certain stages of gestation and the overall differences between the two diets were not significant. In trial 3, feeding more Ca-P (23.6–18.2 vs. 17.8–12.4 g d−1) reduced the percent absorption and retention of energy, Ca, P, Mg, K, Zn, Mn and Cu at several stages of gestation and the overall differences between the two diets were significant for these nutrients. The percent absorption and retention of Ca, P and Mn progressively increased while that of nitrogen, K and Zn decreased with the advancement of gestation. The mineral levels of femurs and metacarpals of gilts and their piglets at birth were similar for both diets. The results indicated that feeding more Ca-P during gestation had minimal influence on amount of energy, nitrogen Ca and K absorption and retention but it increased the amount of P absorption and retention; however, the reduction of Zn, Mn and Cu absorption may cause deficiencies with inadequately supplemented diets. Key words: Gilt, gestation, minerals, energy, nitrogen, absorption, retention
STEREOTYPIC BEHAVIOR AND PRODUCTIVITY OF SOWS
Authors: BORELL E. VON , HURNIK J. F.
Published: March 2010

The behavior of 37 gestating sows in different parities was observed around day 85 of pregnancy. Seventeen sows exhibited stereotypic behavior for 54.9 ± 4.8% of the 8-h observation period. The total time the sows spent standing and sitting was correlated with age (rs = 0.43, P < 0.01) and was significantly different (P < 0.001) for sows which performed stereotypic behavior S than for sows that did not N. S sows had fewer piglets born alive (P < 0.1) but mean litter weights at 3 wk (P = 0.48) did not differ from those of N sows. The time spent on stereotypic behavior within the S group, however, was positively correlated with the number of piglets born alive (rs = 0.5, P < 0.05). Results indicate that the performance of stereotypic behavior in individually housed gestating sows correlates with litter size. Key words: Stereotypic behavior, gestating sow, productivity, housing
THE INFLUENCE OF GONADOTROPHIN-RELEASING HORMONE AT ESTRUS ON OVULATION RATE AND THE DEVELOPMENT OF CORPORA LUTEA IN EWES
Authors: KIRKWOOD R. N. , THACKER P. A. , RUTTER L. M. , AHERNE F. X.
Published: March 2010

Twenty-two ewes received either 30 μg GnRH or saline at the onset of estrus. Blood samples were obtained on days 1–7 (day 0 = estrus) and corpora lutea recovered surgically at day 7. There was no effect of GnRH on the number or weight of corpora lutea nor on the concentrations of progesterone in either corpora lutea or plasma. GnRH treatment caused an increase (P < 0.07) in luteal hCG binding capacity (0.66 ± 0.12 vs. 0.34 ± 0.12 nmol mg−1 protein). Key words: GnRH, estrus, corpora lutea, hCG binding
PROGESTERONE PRODUCTION IN VITRO BY LUTEAL CELLS FROM HORMONALLY-INDUCED PREPUBERTAL GILTS
Authors: AGU G. O. , BUHR M. M.
Published: March 2010

Cultured, unstimulated, large and small luteal cells from day 15 prepubertal gilts (day 0 = PMSG/hCG injection) produced significantly more progesterone than corresponding day 18 cells. Progesterone production by large and small day 15 and day 18 cells was stimulated by lipoproteins (P < 0.05) but not LH. Luteal cells from induced prepubertal CL therefore can respond to certain luteotropins. Key words: Progesterone, induced puberty, lipoproteins, luteal cells
THE INFLUENCE OF GROWTH HORMONE TREATMENT ON THYROID FUNCTION IN SWINE
Authors: KIRKWOOD R. N. , THACKER P. A. , LAARVELD B.
Published: March 2010

Twelve castrated male pigs of Yorkshire and Landrace breeding were selected at 95.9 ± 1.6 kg body weight (BW) and allocated equally to receive daily injections of either porcine growth hormone (pGH) at 90 μg kg−1 BW or vehicle buffer for four consecutive days. Following the last pGH injection, the pigs were infused via indwelling vena caval cannulae with thyrotropin-releasing hormone (TRH) at 0.5 μg kg−1 BW. Blood samples were obtained at 10 and 0 min before TRH and thereafter at 10-min intervals for 90 min. Serum concentrations of thyroxine and thyrotropin were lower (P < 0.06 and P < 0.1, respectively) but those of triiodothyronine higher (P < 0.01) in pGH-treated pigs throughout the sampling period. There were no significant treatment-by-time interactions indicating that the thyroid response to TRH was not influenced by pGH treatment. Key words: Swine, thyroid, growth hormone, somatotropin
THE USE OF RAPID ON-FARM MILK PROGESTERONE TESTS AS AN AID TO REPRODUCTIVE MANAGEMENT IN DAIRY CATTLE
Authors: RAJAMAHENDRAN R. , KEELING B. J. , ROBINSON J. , RAVINDRAN V.
Published: March 2010

A field study was conducted in 11 commercial dairy herds to test the accuracy and ease of use of a rapid enzyme-linked immunosorbent assay (ELISA) kit for on-farm milk progesterone analysis. Milk samples were collected at milking following detection of estrus and on day 21 postbreeding. Progesterone was measured on-farm by producers using an ELISA kit and by a technician in the laboratory using a radioimmunoassay (RIA). Of the 256 samples collected at suspected estrus, estrual concentrations of progesterone (≤ 2 ng mL−1) were detected in 246 samples by the farmer and in 253 samples by laboratory analysis. Nonestrual concentrations (> 2 ng mL−1) were detected in 10 samples by the farmer and in three samples by RIA. At 21 d, there was 94% agreement between the two methods in detecting high (> 2 ng mL−1) milk progesterone concentrations (n = 149). The corresponding figure for low (≤ 2 ng mL−1) milk progesterone was 88% (n = 73). Seventy-two percent of the cows with high milk progesterone (by RIA) at 21 d were subsequently diagnosed pregnant by rectal palpation. The overall agreement between ELISA and RIA was 96.6% (453/469 samples). No significant differences were observed among farmers in their ability to perform ELISA tests on-farm. The results indicate that the ELISA kits can be used with ease by producers and are comparable in accuracy to RIA performed in the laboratory for detection/confirmation of estrus and diagnosis on nonpregnant/possibly pregnant cows at 21 d postbreeding. Key words: On-farm tests, progesterone, reproductive management, dairy cattle
EFFECT OF SOMATOSTATIN AND CHRONIC COLD EXPOSURE ON HORMONAL AND METABOLITE CONCENTRATION, METABOLIC RATE, THERMOREGULATION, AND GUT MOTILITY IN SHEEP
Authors: CHRISTENSEN R. A. , CHRISTOPHERSON R. J. , KENNELLY J. J.
Published: March 2010

The effect of somatostatin-14 (SS-14) (6.7 ng min−1 kg−1 BW) on hormone and metabolite concentrations, gastrointestinal motility, thermoregulation, and heat production was studied in five ewe lambs (45.8 ± 2.8 kg BW) adapted to either thermoneutral (TN) (17.4 °C) or chronic cold (CC) (− 0.9 °C). Lambs received a barley:soybean diet at 25.6 g DM d−1 kg−1 BW. Environmental temperature and SS-14 infusion had no effect on the frequency or duration of components of the duodenal migrating myoelectric complex (MMC), although cold exposure increased (P < 0.05) total number of contractions within the MMC. CC increased (P < 0.05) heat production by 41%, while SS-14 decreased (P < 0.05) heat production by 4% in both environments. Plasma concentrations of free fatty acids (P < 0.05) were increased during cold exposure. In response to SS-14 infusion plasma free fatty acid levels increased (P < 0.05) in the TN environment, while their level declined in the cold environment. Growth hormone, glucagon, and insulin concentrations were not influenced by cold exposure or SS-14 infusion. CC increased plasma T3 concentration but this response was abolished by SS-14. Thus, in lambs fed a concentrate diet, somatostatin at low doses slightly reduces whole body metabolism, possibly by an influence on thyroid hormones. Key words: Cold, somatostatin, gastrointestinal motility, sheep, metabolism, thyroid
THE INFLUENCE OF DIETARY MONENSIN ON THE LH RESPONSE TO GnRH OR ESTRADIOL AND THE OVULATORY RESPONSE TO PMSG IN GILTS
Authors: KIRKWOOD R. N. , THACKER P. A. , KORCHINSKI R. S.
Published: March 2010

To test the effects of monensin on endocrine responsiveness, 43 gilts of Yorkshire and Landrace breeding were individually fed a 16% crude protein basal diet (CT, n = 22) or the basal diet incorporating 33 mg kg−1 monensin (M, n = 21) for 25 d. Gilt weights and feed intakes were recorded at 7-d intervals for 21 d. Monensin did not significantly affect weight gain or feed intake but feed conversion was improved (P < 0.03). At 21 d, M (n = 6) and CT (n = 7) gilts were fitted with vena caval canulae and infused with 50 μg GnRH. Blood samples were obtained at 10-min intervals from 30 min before to 60 min after GnRH infusion. After a 48-h recovery period, these gilts received an injection of estradiol-17 B (E2) and further blood samples taken at the time of injection, at 24 and 36 h then at 6-h intervals until 78 h. All serum samples were assayed for LH and FSH concentrations. The LH response to GnRH was not affected by monensin, peak values being achieved in both groups 30 min after infusion. Serum FSH was not significantly influenced by GnRH in either group. Following E2 injection, the LH surge height was greater (P < 0.09) in monensin-fed gilts and a treatment by time interaction was evident (P < 0.001). Serum FSH was elevated in both groups but was unaffected by monensin. At 21 d, non-blood sampled gilts received an injection of 750 IU PMSG and were slaughtered 10 d later. An ovarian examination indicated that monensin-fed gilts tended (P < 0.1) to have a lower ovulation rate (13.2 ± 1.0 vs. 17.4 ± 1.9 for M and CT gilts, respectively). These data suggest that the feeding of monensin to gilts alters hypothalamic/pituitary responsiveness to stimulation and may enhance growth performance. Key words: Gilts, monensin, LH, FSH
BUOYANCY SEPARATION OF PARTICLES OF FORAGE, FECES, AND RUMINAL CONTENTS AND NUCLEAR MAGNETIC RESONANCE EXAMINATION
Authors: LIRETTE A. , MILLIGAN L. P. , CYR N. , ELOFSON R. M.
Published: March 2010

The relationships between buoyancy of soaked particles and chemical composition of bromegrass hay stems and ruminal and fecal particulate matter from a steer fed brome hay were studied. Ruminal fluid from one steer fed at maintenance was put in a cylinder and particles previously soaked in physiological saline were added to the top of this fluid. The cylinder was then emptied from the bottom with each 200-mL stratum being collected separately. The dry matter content of each stratum was determined and used to construct buoyancy curves. The shape of the particles in the different strata was examined and their chemical composition determined by high resolution solid state 13C-NMR. The particles from ground bromegrass hay stems, rumen and feces which sank most slowly were long and thin and contained a high proportion of proteins. In the rumen, the large particles (> 3.35 mm) from the upper stratum, which is the floating mat, appeared to contain more peptides and proteins, and less lignin. The feces particles contained a low concentration of proteins and a relatively large amount of lignin, and had a lower buoyancy than hay stems and ruminal particles. It was concluded that there are relationships between buoyancy, physical attributes and chemical and nutritive composition of different types of particles. Key words: Buoyancy, feed, NMR, nutritive value, shape, ruminants
INTERACTIVE EFFECTS OF LOW VOLTAGE ELECTRICAL STIMULATION AND LEG RESTRAINT ON MEAT QUALITY OF CHAROLAIS CROSSBRED STEER CARCASSES
Authors: BRUCE H. L. , JONES C. R. , BALL R. O.
Published: March 2010

The meat quality of the longissimus muscle of 12 Charolais crossbred steers that were electrically stimulated on randomly selected sides approximately 1 h postmortem was investigated. Temperature and pH measurements were taken on each side at 5 min prior and 1, 4, 24 and 48 h subsequent to stimulation and analyses performed following 7-d ageing for soluble, insoluble and total collagen and muscle protein solubility. Although there were no significant differences between the treatments for pH and temperature decline and collagen and protein characteristics, the unrestrained, stimulated sides had significantly lower shear force values than restrained, stimulated sides. Key words: Collagen solubility, electrical stimulation, beef, Charolais
NUCLEAR MAGNETIC RESONANCE IMAGING AND PROTON SPECTROSCOPY USED AS A TECHNIQUE TO ASSESS MAMMARY GLAND COMPOSITION IN HOLSTEIN HEIFERS
Authors: STELWAGEN K. , McBRIDE B. W. , GRIEVE D. G. , TOWNER R. A.
Published: March 2010

Mammary glands of eight nonpregnant, nulliparous Holstein heifers (416 ± 11 d) were used to study the potential for nuclear magnetic resonance (NMR) imaging and proton spectroscopy as a technique to assess mammary gland composition. It was concluded that the NMR technique has the potential to quantitate mammary gland composition in heifers. Key words: Nuclear magnetic resonance imaging and spectroscopy, mammary composition, Holstein heifers
THE EFFECTS OF WITHHOLDING FEED AND WATER ON SELECTIVE BLOOD METABOLITES IN MARKET-WEIGHT BEEF STEERS
Authors: SCHAEFER A. L. , JONES S. D. M. , TONG A. K. W. , LEPAGE P. , MURRAY N. L.
Published: March 2010

Eighty crossbred beef steers weighing an average of 493.4 ± 3.2 kg were allocated to five treatment groups of 0, 12, 24, 36 or 48 h off feed and water in order to examine the effects on selective blood metabolites. Progressive increases (P = 0.01) were observed in serum chloride, red blood cells, hemoglobin and hematocrit simultaneously with reductions in serum glucose and, by implication, plasma volume. Changes were most noticeable between 24 and 36 h off feed and water. Key words: Cattle, fasting, metabolites, carcass
THE GENESIS OF A GRAY LUVISOL WITHIN THE BOREAL FOREST REGION. II. DYNAMIC PEDOLOGY
Authors: HOWITT R. W. , PAWLUK S.
Published: March 2010

An undisturbed site under forest cover near Breton, Alberta, was chosen to study the dynamics of a Gray Luvisol. Soil moisture and temperature were monitored at selected depths over a 2-yr study period. Canopy drip collectors and gravity lysimeters were used to study soil solution transport and the process of lessivage. The order of cation concentration for canopy drip, LFH and Ae lysimeter samples was K+ > Ca++ > Na+ > Mg++. The lysimeter samples from the Bt showed Na+ > Ca++ > K+ > Mg++. Lysimeter studies further indicated that micaceous clays were being illuviated into the upper Bt horizon. Water movement into the Ae horizon was found to be regulated by the LFH horizon; ice lensing in winter appeared to enhance the formation of the platy structure. The major processes in this soil are the translocation of Fe, Al and organic constituents both in solution and in colloidal form; the concentration of these elements was a function of the rate of water movement. The concentration of other cations was independent of the rate of water movement. Key words: Genesis, pedogenesis, Gray Luvisol, dynamic pedology, clay migration, lessivage, illuviation
MICRONUTRIENT STATUS OF SELECTED CACAO-GROWING SOILS IN SOUTHWESTERN NIGERIA: PROFILE DISTRIBUTION OF TOTAL AND AVAILABLE ZINC
Authors: CHUDE V. O. , OBIGBESAN G. O. , EGBE N. E.
Published: March 2010

A study was conducted to determine the content and distribution of total 1.0 M NH4OAc-, 0.1 M HCl-, 1 M MgCl2-, and 0.005 M DTPA-extractable Zn in the genetic horizons of 16 soil profiles from major cacao-growing areas in Southwestern Nigeria. The content of total Zn for all the soils varied from 12 to 92 μg/g with soils derived from igneous and metamorphic rocks containing more than those of sedimentary origin. Most of the soils had the highest concentration of total Zn in the surface horizons. There was a strong association between total Zn and organic matter, total Zn and silt/clay content. The 1 M NH4OAc-, 0.1 M NCl-, 1 M MgCl2- and 0.005 M DTPA-extractable Zn in all the soils and horizons varied from 0.17 to 5.6, from 0.06 to 2.37, from 0.20 to 1.20 and from 0.022 to 1.14 μg Zn/g, respectively. The NH4OAc generally removed more Zn than the other three extractants. The amount of Zn extracted showed a general decrease with depth. A significant amount of MgCl2-extractable Zn appeared to be associated with silt content while soil pH influenced the quantity of Zn extracted by the NH4OAc method. Key words: Total Zn, NH4OAc-extractable N, HCl-extractable N, MgCl2-extractable N, DTPA-extractable Zn, soil profile
COMPARAISON DE DIFFERENTES METHODES D’EXTRACTION DU P ASSIMILABLE EN RELATION AVEC LES PROPRIETES CHIMIQUES ET PHYSIQUES DES SOLS DU QUEBEC
Authors: TRAN T. SEN , GIROUX M.
Published: March 2010

The objective of this study was to compare different available-P extracting methods on 83 Québec soils. The alkaline Olsen’s method and five acid chemical extractants (Bray-1, Bray-2, new Mehlich, North Carolina double acid DA-4 and DA-10) were compared with each other and with two anion-exchange resin methods. The ratio of P-HCl/P-DAF of Mehlich was used to identify the group of soils with predominant P-Ca forms [Formula: see text]. Within this soil group, the Bray-2, DA-4 and DA-10 methods extracted more P and they were less correlated with all the other methods (r = 0.01 to 0.48*). The Bray-1 and Mehlich methods showed good relationships with Olsen, F−- and HCO3−-form resin methods (r = 0.80** to 0.89**) for this soil group, with the exception that Bray-1 solution was more affected by the presence of free carbonates. In the soil group containing more than 0.6% oxalate-Al, the Bray-1, Bray-2 and DA-10 methods extracted more P than the Mehlich, DA-4 or Olsen methods. The F−-form exchange resin extracted more P than that in the HCO3− form. The depressing effect of free iron oxides on the DA-4 method was also observed with the soil group containing more than 0.6% oxalate-Fe. The contents of DA-4-P were less correlated with those of other methods (r = 0.74** to 0.88**) in this soil group. On the other hand, the Olsen, F− and HCO3− resins extracted more of the P-Fe forms from these soils. The DA-4 method was further influenced by the soil organic matter (OM) contents. The relationships between P-Olsen, P-HCO3−-resin with the other chemical methods were also improved by taking into account the contribution of OM contents. Soil texture influenced mostly Bray-2, Bray-1, DA-4 and DA-10 extractable P. The Mehlich, Olsen and F−-resin extractable P was less affected by clay contents while the HCO3−-resin was the most consistant over a wide range of soil textures. Key words: Available-P, anion-exchange resins, new Mehlich extractant, P-forms, soil testing
CHEMICAL CHARACTERISTICS OF SOILS UNDER SPRUCE-FIR FORESTS IN EASTERN MAINE
Authors: FERNANDEZ I. J. , STRUCHTEMEYER R. A.
Published: March 2010

Soils supporting even-aged spruce-fir stands in eastern Maine are highly acid with soil pH often found to be a useful indicator of potential tree growth. This investigation examined the chemical characteristics of these soils at 22 spruce-fir sites and the relationship between soil chemical properties and site productivity. Each major soil horizon exhibited a distinctly different chemical environment. Spruce-fir site productivity was found to be significantly correlated with B horizon organic-P, O horizon pH, and the total organic matter content of the mineral soil horizons. Soil pH increased with depth in the profile ranging from a mean value of 3.13 in the O horizon (i.e. F + H) to 4.91 in the C horizon. Significant correlations were exhibited between pH and exchangeable Ca, exchangeable Al, and extractable Al throughout the profile. Fractionation of P in the B horizons demonstrated that occluded-P was the most concentrated of the fractions measured, with the order of relative abundance for the P fractions being occluded-P > Al-P > organic-P > Fe-P > Ca-P > extractable-P. Sampling of soils for evaluating the potential for forest growth in this region must be carried out by horizons, as these differ remarkably with respect to those variables that have been shown to have an influence on tree growth. Key words: pH, site quality, organic matter, phosphorus, aluminum, spruce-fir
SHOOT AND ROOT RESPONSE OF WHEAT TO BAND AND BROADCAST PHOSPHORUS AT VARYING SOIL TEMPERATURES
Authors: SHEPPARD S. C. , RACZ G. J.
Published: March 2010

Response of spring wheat (Triticum aestivum) to varied amounts of broadcast and band-applied phosphorus (P) was examined at soil temperatures of 10, 15, 20 and 25 °C. The research emphasized the response of shoot yields with time and the root proliferation in the band-applied P. A non-destructive technique to measure growth with time was developed. This method allowed interpretation of plant responses even though the temperature treatments markedly changed the rate of physiological development. The relative plant-shoot response to P application did not change with time or developmental stage in this experiment. There was a marked effect of temperature on plant response to band-applied P. Band application was more efficient than broadcast P at 10 °C soil temperature, but less efficient at 25 °C soil temperature. Root proliferation in the fertilizer band was significantly different from the control soil-zone only at 10 °C and was not diminished by concurrent application of broadcast P. The efficiency of band application was confirmed with 32P labelling of the banded P. Banded P accounted for more of the total plant P at lower soil temperatures than at higher soil temperatures, regardless of concurrent application of broadcast P. Temperature had little effect on yield response to broadcast P at the final sampling or throughout the growth period. Tissue P concentrations decreased with increases in temperature and with time. Key words: Temperature, root proliferation, band, broadcast, phosphorus
THE COPPER FERTILITY OF SASKATCHEWAN SOILS
Authors: KRUGER G. A. , KARAMANOS R. E. , SINGH J. P.
Published: March 2010

A survey of the DTPA-extractable Cu levels of approximately 1000 fields representing a large number of soil types in Saskatchewan suggested that, under current cropping systems, Cu deficiencies appear to be concentrated in the Grey Soil Zone. They are especially probable in seven soil associations, which include light Transition of Grey and Brownish-Grey Podzolic soils. Soil criteria for detecting Cu deficiencies in cereal crops cannot be fully documented using conventional calibration tests and techniques. However, data from 21 field trials and a growth chamber study indicated that the critical level of DTPA-extractable Cu in these soils is approximately 0.4 mg∙kg−1 for cereals. Large spatial variability of DTPA-extractable Cu levels has been found to occur in a level field, thus suggesting that the Cu status of a field may not be adequately described by assessing the Cu levels of composite field samples. Key words: DTPA-extractable Cu, soil survey, critical level, spatial variability
EFFECT OF IONIC STRENGTH AND SOLUTION pH ON P EXTRACTABILITY AND LEACHING IN COARSE-TEXTURED SOILS
Authors: EVANS Jr. A. , SORENSEN R. C.
Published: March 2010

A laboratory study was conducted using columns of Valentine loamy sand to determine the effect of ionic strength (I) and solution pH of a leaching solution on P distribution and extractability with depth. Solutions of KCl at concentrations of 1.0, 10−2, 10−4 and 10−6 mol∙L−1 with a pH of either 4.0, 6.0, or 8.0 were added to the column after the application of 0.3 g diammonium phosphate to the surface of each column. Approximately two pore volumes, 500 mL of solution, were added to the columns, after which they were sectioned and the amount of Bray extractable P in each section was measured. Increasing I resulted in an increase in the total amount of Bray extractable P per column while extractable P increased with column depth for decreasing I. The pH of the leaching solution did not influence the total amount of Bray extractable P per column, but appeared to influence P distribution for the I = 10−2 treatment. Dissolved organic carbon in the leachate was found to increase with decreasing I. Changes in the distribution of extractable P with depth were attributed to increased competition for P adsorption sites by various organic molecules, which were released into the bulk solution when the organic matter coatings underwent a transition from the spherocolloid to the linear flexible molecule configuration. Key words: Ionic strength, P movement, organic matter coatings, spherocolloid, anion competition
COMPARISON OF OBSERVATIONS AND MACROCLIMATIC MODEL ESTIMATES OF MONTHLY WINTER SOIL TEMPERATURES AT OTTAWA
Authors: DWYER L. M. , HAYHOE H. N.
Published: March 2010

Estimates of monthly soil temperatures under short-grass cover across Canada using a macroclimatic model (Ouellet 1973a) were compared to monthly averages of soil temperatures monitored over winter at Ottawa between November 1959 and April 1981. Although the fit between monthly estimates and Ottawa observations was generally good (R for all months and depths 0.10, 0.20, 0.50, 1.00 and 1.50 m was 0.90), it was noted that midwinter estimates were generally below observed temperatures at all soil depths. Data sets used in the development of the original Ouellet (1973a) multiple regression equations were collected from stations across Canada, many of which have reduced snow cover. It was found that the buffering capability of the snow cover accumulated at Ottawa during the winter months was underestimated by the pertinent partial regression coefficients in these equations. The coefficients were therefore modified for the Ottawa station during the winter months. The resultant regression models were used to estimate soil temperature during the winters of 1981–1982 and 1982–1983. Although the Ottawa-based models included fewer variables because of the smaller data base available from a single site, comparisons of model estimates and observations were good (R = 0.84 and 0.91) and midwinter estimates were not consistently underestimated as they were using the original Ouellet (1973a) model. Reliable monthly estimates of soil temperatures are important since they are a necessary input to more detailed predictive models of daily soil temperatures. Key words: Regression model, snowcover, stepwise regression, variable selection
PHOTOGRAMMETRIC DETERMINATION OF TERRAIN SLOPE USING SIMPLE EQUIPMENT
Authors: WILSON G.
Published: March 2010

Slope is an important factor in terrain mapping and can be determined from contour maps or aerial photographs. Previously methods have been proposed to reduce the time element using contour maps. This paper describes and demonstrates a technique whereby aerial photographs can be used effectively when photogrammetric equipment and reliable contour maps are not available. Accuracy with the method is illustrated by comparison to slope determined from a contour map and a single computation sheet is provided for inclusion in a handbook or field guide. Key words: Slope measurement, terrain analysis, pedotechnical interpretations, aerial photos, photo interpretation, photogrammetry
THE SULPHUR STATUS OF EASTERN CANADIAN PRAIRIE SOILS: THE RELATIONSHIP OF SULPHUR, NITROGEN AND ORGANIC CARBON
Authors: BAILEY L. D.
Published: March 2010

Surface and subsurface samples of 17 of the most agriculturally important soils of the eastern Canadian prairies were analyzed for total S, sulphate S, total N and organic C. The soils varied in texture from sandy loam to clay loam. Fifteen of the soils were of the Chernozemic order, one was Brunisolic and the other Luvisolic. The subgroups included were Orthic Blacks, Gleyed Rego Blacks, Orthic Dark Greys, Eluviated Eutric Brunisol and Orthic Luvisol. The total S of the soils decreased with depth and was significantly correlated with total N and with organic C. The sulphate sulphur extracted with 0.1 M CaCl2 accounted for an average of 2.6% of the total S in each of the three soil depths analyzed. The calculated N:S and C:N ratios averaged 8.3 and 1.25 (0–15 cm), 7.2 and 14.1 (15–30 cm), and 6.5 and 11.0 (30–60 cm), respectively. The N:S ratios, and to limited extent the C:N ratios, were used to describe the sulphur status of the soils. Soil with N:S and C:N ratios 6.0 and 12.5 (0–15 cm), 5.2 and 13.5 (15–30 cm), 4.7 and 11.4 (30–60 cm), respectively, could have a high potential to supply sulphate S to plants and may not be deficient in plant-available S. Soils with N:S and C:N ratios of 8.7 and 13.5 (0–15 cm), 7.2 and 14.7 (15–30), 6.3 and 11.2 cm (30–60 cm), respectively, may be deficient in sulphur for some crops. However, they may have a high potential to convert total S to sulphate S. Soils with N:S and C:N ratio of 12.4 and 11.2 (0–15 cm), 11.1 and 13.0 (15–30), 10.2 and 9.9 (30–60 cm), respectively, may be deficient in plant-available S and could have a low potential for conversion of total S to sulphate S. Key words: Sulphur status of soils; potential available sulphur
GASEOUS NITROGEN LOSSES FROM CONVENTIONAL AND CHEMICAL SUMMERFALLOW
Authors: AULAKH M. S. , RENNIE D. A.
Published: March 2010

The gaseous losses of N (N2O + N2) measured for 130 days (May-September 1983) from conventional fallow at Yorkton, Oxbow and Weyburn soil sites ranged from 9 to 11, 15 to 31 and 60 to 87 kgN∙ha−1 for upper, middle and lower slope positions, respectively. The corresponding values for chemical fallow were 18–28, 24–51, and 69–98 kgN∙ha−1. In both tillage systems, gaseous N losses increased in the order of upper < middle < lower slope positions and were associated with the variations in soil moisture. The results obtained from additional widely scattered field studies on chernozemic soils further confirmed that the more dense surface soil and relatively higher soil moisture (lower air-filled porosity) were the major factors affecting increased denitrification under chemical fallow. Volumetric soil moisture was the only factor which showed a very highly significant correlation with N2O emmisions. Key words: Acetylene inhibition-soil core technique, chemical fallow, denitrification, nitrification
AZIDE EFFECTS UPON N2O EMISSION AND TRANSFORMATIONS OF N IN SOILS
Authors: AULAKH M. S. , RENNIE D. A.
Published: March 2010

N2O emissions from soils under aerobic conditions were severalfold higher in the presence of azide (1 mM) than in its absence. Nitrogen, added either as NH4+ or NO3−, had no effect on the azide’s induced N2O production. Although the physiological basis by which azide induces the very high evolution of N2O remains unknown, it cannot be attributed to nitrification as a source of N2O emission in the presence of azide, the inhibitory effect of azide on the reduction of N2O to N2, or to the extensive destruction of azide by nitrite under the conditions of the present study. A possible explanation may lie in the stimulation of denitrification processes due to the azide’s role in the synthesis of denitrifying enzymes. This study has reconfirmed that, like N-serve and C2H2, azide (1 mM) is a very effective inhibitor of nitrification. However, azide had no effect on the oxidation of NO2− to NO3−, and was also shown not to be a general inhibitor of microbial activity. Key words: Denitrification, nitrification, dissimilatory nitrase reductase, denitrifying enzymes
RELATIONSHIPS BETWEEN LEAF AND SOIL BORON AND BORON TOXICITY OF PEACHES IN BRITISH COLUMBIA
Authors: NEILSEN G. H. , HOYT P. B. , YORSTON J. , LIEROP W. VAN
Published: March 2010

Soil and leaf boron were determined in British Columbia peach orchards exhibiting a range of B concentration, including suspected toxicity. B toxicity always occurred when leaf concentration in May exceeded 130 mg/kg, and frequently occurred when leaf B concentration in July was between 50 and 83 mg/kg. Revised leaf standards were suggested to indicate a desirable range of 26–50 mg/kg leaf B in July. Leaf and soil B for peaches were generally correlated. Exceptions occurred when soil B was concentrated near the soil surface or deep in the soil profile. Leaf B in July was from 26 to 50 mg/kg when soil B to a 90-cm depth ranged from 0.2 to 0.4 mg/L of soil. Key words: Boron toxicity, leaf and soil B, peaches
EVALUATION OF THE EROSION INDEX FOR THE PRAIRIES
Authors: KACHANOSKI R. G. , JONG E. de
Published: March 2010

Ateshian’s (1974) equation, used by Wall et al. (1983) to calculate the USLE rainfall erosion index (R) for Canada, appears to considerably overestimate the actual R value for Saskatchewan. An alternative equation derived using a generalized distribution curve for prairie rainstorms given by McKay (1970) predicted an R value of 350 for Saskatoon which was close to the 12-yr average (R = 340) for Saskatoon calculated from tipping bucket rain data. More R values need to be calculated from existing climatological data to determine which (if any) estimation equation is satisfactory. Key words: Rainfall factor, prediction, USLE
PREDICTING VOLUMETRIC WATER RETENTIONS FOR SUBSOIL MATERIALS FROM COLCHESTER COUNTY, NOVA SCOTIA
Authors: BEKE G. J. , MacCORMICK M. I.
Published: March 2010

Relationships between soil water retention and soil properties were developed for subsoil materials from Colchester County, Nova Scotia. The significant variables in the regression equation for soil water content at a suction of 33 kPa were the sand content and the product of silt content and bulk density of the soil. The variables for water retention at 1500 kPa suction were the clay content and the product of organic matter content and bulk density. The multiple correlation coefficients were 0.87 and 0.92 for suctions of 33 and 1500 kPa, respectively. The developed equations were comparable to ones derived elsewhere. Key words: Water retention, texture, organic matter, bulk density
EFFETS DES DOSES DE MANGANESE, D’ALUMINIUM, DES REGIMES HYDRIQUES ET DU pH DES SOLS SUR LES RENDEMENTS DE LUZERNE ET SUR L’ASSIMILABILITE DU MANGANESE ET DE L’ALUMINIUM
Authors: DIONNE J. L. , PESANT A. R.
Published: March 2010

Alfalfa (Medicago sativa L. ’Saranac’) was grown on Ste. Rosalie clay, Greensboro loam and St. Jude sand adjusted to about pH 5.0, 6.5 and 7.5 in a greenhouse experiment, to determine the changes in response of alfalfa to aluminum and manganese resulting from variations in soil pH and soil moisture. Rates of Mn were equivalent to 0 and 200 kg∙ha−1 and rates of Al were 0, and 100 kg∙ha−1. Three soil moisture regimes were used: (1) Optimum with soil moisture between field capacity (FC) and 70% of this value. (2) Wet: with soil moisture between saturation point (SP) and FC. (3) Very wet: with soil moisture between saturation point and a value half way between SP and FC. Manganese applied on acid soils (pH 5.2) under optimum soil moisture regimes decreased alfalfa yields by 3% only, compared to a 62% decrease in alfalfa yields by Mn applied on acid soils of the two high soil moisture regimes. This was due to a high level of Mn in alfalfa on the wet acid soils. A large quantity of aluminum was also found in alfalfa grown in acid soils along with a high concentration of "extractable" aluminum. This resulted in a 54% reduction of alfalfa yields. Content of Al and Mn in alfalfa top and in soils was decreased sharply by liming soils at pH of 6.5 or 7.5. On soils limed to a pH of about 7.0 alfalfa survived at high levels of Mn and Al such as frequently encountered in some acid and very wet soils. Key words: Soil Mn, soil Al, soil pH, soil moisture, alfalfa
SOIL TEMPERATURE UNDER ZERO TILLAGE SYSTEMS FOR WHEAT IN SASKATCHEWAN
Authors: CARTER M. R. , RENNIE D. A.
Published: March 2010

Soil temperature profiles and the aerial growth of wheat were characterized over portions of the growing season in 1980 and 1981 under zero and conventional tillage systems in a semi-arid region of Saskatchewan. Differences in maximum and minimum soil temperature, accumulative heat sums and thermal diffusivity over the 2.5-cm to 20-cm soil depth were related to variations in surface crop residues, soil moisture and crop canopy. Generally, maximum soil temperatures were 1–5 °C lower under zero tillage compared to conventional tillage during the first 30 days of crop growth for spring wheat. Similar soil temperature differences were evident between winter wheat zero tilled on stubble or chemical fallow during the period of early spring growth. Subsequent differences in crop canopy (shoot height), between tillage systems, tended to modify the soil temperature profile. Soil temperature differences were not associated with differences in yields of spring or winter wheat. Key words: Soil temperature, soil thermal properties, zero tillage systems, wheat,semi-arid climate
FALL AND SPRING SOIL SAMPLING FOR MINERAL N IN NORTH-CENTRAL ALBERTA
Authors: MALHI S. S. , WALKER D. R. , NYBORG M. , LAVERTY D. H.
Published: March 2010

The timing of soil sampling for mineral N was investigated by sampling in fall and in spring from the 0- to 30-cm depth in 100 field experiments. On the average of the 100 experiments, the NO3 – N in soil increased from 16 kg N∙ha−1 in fall to 34 kg N∙ha−1 in spring and the mineral N in soil increased from 28 kg N∙ha−1 in fall to 49 kg N∙ha−1 in spring. In 18 of the experiments, fall to spring increase in NO3 – N ranged from 31 to 90 kg N∙ha−1, and 16 of these experiments were among the 56 Black Chernozemic soils in the study. The correlation coefficient (r) between soil NO3 – N in fall and grain yield in check plots was 0.55, while the r value between soil NO3–N in spring and grain yield in check plots was 0.72. When mineral N was used instead of NO3 – N, the r values were similar. The relationship between fall NO3 – N (X) and spring NO3 – N (Y) was best described by the linear regression equation (Y = 14.84 + 1.22 X) with an r value of 0.66. Of the 100 experiments, 26 were sampled twice in the fall (early fall and late fall) and once in the spring. The increase in soil NO3 – N from early fall to spring was 33 kg N∙ha−1, but from late fall to spring was only 15 kg N∙ha−1. The linear regression equation to predict the spring NO3 – N values (Y) from early fall NO3 – N (X) was Y = 27.50 + 1.29 X (r = 0.63) and from late fall NO3 – N (X) was Y = 20.47 + 0.88 X (r = 0.76). The relationship of grain yield (or N uptake) with soil NO3 – N in late fall samples was much closer than with NO3 – N in early fall soil samples, and the correlation was similar to that obtained with soil NO3 – N in spring samples. Even though NO3 – N was substantially less with late fall sampling, as compared to spring sampling, the correlation with the two times were moderately close (r = 0.76). Soil test programs in the Prairie Provinces are based primarily on field experiments with only spring sampling, while farm sampling is mostly conducted in the fall. At least in north-central Alberta, fall sampling for soil test for NO3 – N apparently should be restricted to the late fall and probably an adjustment to N recommendations should be made for the smaller amounts of NO3 – N found in fall rather than spring. Key words: Early fall, late fall, mineral N, nitrate N, N recommendations, soil sampling, spring
COLOR AS A CRITERION FOR THE RECOGNITION OF PODZOLIC B HORIZONS
Authors: EVANS L. J. , CAMERON B. H.
Published: March 2010

Three hundred and fifty-three B horizons from acidic, well- to imperfectly drained soils from northern Ontario were sampled in an effort to test and possibly refine the current color and pyrophosphate-extractable Fe and Al criteria as presently used in the Canadian System of Soil Classification. Each of the soils sampled displayed podzolic morphology in the form of reddish brown to brown B horizons that became yellower and/or paler with depth and underlay LFH and Ae horizons. The soils belonged to the Podzolic (171 sites) and Brunisolic (182 sites) Orders. It was found that as the hues became redder and the values darker there were increases in the means of pyrophosphate-extractable Fe (Fep), and Al (Alp) and of C (Cp). Soils with sand textures (sands and loamy sands) required less Fep plus Alp to give the same colors as finer textured soils. Using two schemes for attributing color codes to the Munsell Colour Chips, Cp was found to be the soil property most highly correlated with soil color. By revising the current color and Fep and Alp criteria it was found that the soils could be correctly classified using color 78% of the time, compared with only 52% using the present criteria. Key words: Soil color, soil classification, pyrophosphate-extractable Fe, Al, C
ATRAZINE HYDROLYSIS IN SOILS: CATALYSIS BY THE ACIDIC FUNCTIONAL GROUPS OF FULVIC ACID
Authors: GAMBLE DONALD S. , KHAN SHAHAMAT U.
Published: March 2010

The catalysis of atrazine hydrolysis at 25.0 °C by the types of acidic functional groups found in humic materials has been investigated. No evidence of catalysis by carboxylate ions was observed. From a knowledge of the types and numbers of acid functional groups in a quantitatively characterized fulvic acid, and the distributions of their KA values it was found that hydrogen ions and undissociated carboxyl groups were the only catalytic agents. The carboxyl groups have a second-order kAH of 7.88 days −1∙M−1. Weakly acidic functional groups having [Formula: see text]showed no catalysis. A predictive equation has been produced for the half-life of atrazine in fulvic acid solutions at 25.0 °C. It represents a general class of equations which should permit the practical prediction of atrazine persistence in soil solutions and other natural waters. Key words: Atrazine hydrolysis, atrazine persistence, fulvic acid, fulvic acid carboxyls, acid catalysis, carboxyl catalysis