bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of sunflower seed supplementation on the fatty acid composition of muscle and adipose tissue of pasture-fed and feedlot finished beef
Authors: Basarab J. A. , Mir P. S. , Aalhus J. L. , Shah M. A. , Baron V. S. , Okine E. K. , Robertson W. M.
Published: April 2011

This study examined the effects of whole sunflower seed (WSS) supplementation on pasture and in finishing diets on the fatty acid profile of muscle [gastrocnemius (GN), longissimus thoracis (LT), intercostals (IC)] and adipose tissue [subcutaneous (SQ), intermuscular (IM)]. Ninety-six yearling steers averaging 410 kg were randomly allocated to three pasture (P) dietary treatments: (1) supplemented with WSS (P-WSS, n = 48); (2) supplemented with cracked barley grain (P-BAR, n = 24), and (3) not supplemented (P-CON, n = 24). Steers rotationally grazed meadow bromegrass-alfalfa pasture for 66 d. After 66 d on pasture, half the steers from each dietary treatment were trucked to a feedlot where they were adjusted to finishing diets. The remaining 48 steers continued with their dietary treatment on stockpiled pasture for an additional 47 d (SD = 11) until they were slaughtered directly off pasture. In the feedlot, half the steers from each pasture dietary treatment were fed either a control (83% rolled barley, 10% alfalfa hay, 5% barley silage, 1% molasses and 1% vitamin/mineral premix; F-CON) or a WSS supplemented diet (68% rolled barley, 15% WSS, 10% alfalfa hay, 5% barley silage, 1% molasses and 1%; F-WSS). Provision of WSS to steers grazing pasture for 113 d followed by direct slaughter increased cis-9, trans-11 CLA content in the muscles by 17.0 to 29.1% (GN, 0.570 vs. 0.467; LT, 0.515 vs. 0.399; IC, 0.531 vs. 0.454 mg 100 mg-1 fat) and in adipose tissue by 32.0% in IM (0.636 vs. 0.482 mg 100 mg-1 fat) and 40.3% in SQ (0.839 vs. 0.598 mg 100 mg-1 fat) fat depots compared with control steer slaughtered directly off pasture. On pasture supplementation of WSS also increased C18:1 trans-11 content in muscle by 20.1 to 40.8% and in IM adipose tissue by 55.0%. The inclusion of WSS in finishing diets increased CLA cis-9 trans-11 content in muscle by 31.5 to 209.0% and in adipose tissue by 40.7% in the SQ fat and 25.6% in the IM fat. It also increased C18:1 trans-11 content in muscle by 80.0 to 207.3% and in adipose tissue by 181% in the IM fat and 224% in the SQ fat. Strong, positive relationships were observed between tissues in the concentration of CLA cis-9 trans-11, C18:1 trans-11 and C18:3 (R2, 0.69–0.88; P < 0.0001). The results indicate that increasing the dietary polyunsaturated fatty acids in beef cattle diets increased the levels of CLA cis-9 trans-11 and C18:1 trans-11 in muscle and fat tissues. Key words: Beef, pasture, feedlot, fatty acid profile, conjugated linoleic acids, vaccenic acid
Feeding a combination of lactate-utilizing and lactate producing bacteria modulates acute phase response in feedlot steers
Authors: Emmanuel D. G. V. , Jafari A. , Beauchemin K. A. , Leedle J. A. Z. , Ametaj B. N.
Published: April 2011

Six ruminally cannulated steers were used in a replicated 3 × 3 Latin square with 2 wk for adaptation and 1 wk for measurements to study the effects of Propionibacterium P15 (P15) alone or in combination with Enterococcus faecium EF212 (PE) on acute phase response. Treatments were: (i) carrier (control), (ii) P15, and (iii) PE. The bacterial treatments [109 colony forming units (CFU) d-1] mixed in whey powder (carrier), or whey powder alone for control animals, were top-dressed once daily at the time of feeding (10 g steer-1 d-1). Blood samples were obtained from jugular veins on the last day of each period at 0, 6, and 12 h after feeding of bacteria and serum amyloid A (SAA), haptoglobin, lipopolysaccharide de-binding protein (LBP) were measured by ELISA and alpha1-acid glycoprotein (α1-AGP) by radial immunodiffusion. Results indicate that feeding P15 alone increased SAA and lowered plasma haptoglobin, whereas, feeding PE elevated concentrations of SAA, but had no effect on plasma haptoglobin. No significant differences were obtained for plasma α1-AGP among the experimental groups. In conclusion, feeding direct-fed microbials induced an inflammatory response in feedlot steers. Key words: Acute phase response, feedlot steers, direct-fed microbials
The effect of concentration and form of dietary nitrogen on the utilization and excretion of nitrogen by lactating dairy cows
Authors: Fisher L. J. , Dinn N. E. , Shelford J. A. , Paul J. W.
Published: April 2011

Three total mixed rations containing differing sources and levels of protein were fed to 18 lactating cows in a 3 × 3 Latin square design with the objective of quantitating nitrogen losses for specific feeding regimes. Feeding a total mixed ration containing 12.3% crude protein reduced the amount of nitrogen excreted and increased the proportion of dietary nitrogen secreted in the milk. The diet supplemented with corn gluten meal resulted in high blood urea nitrogen levels and higher losses of nitrogen in the urine. It was concluded that diet formulation impacts on nitrogen wastage. Key words: Lactating cows, nitrogen source, level and wastage
Beta-adrenergic receptors in skeletal muscles of ruminants: Effects of temperature and feed intake
Authors: Ekpe E. D. , Moibi J. A. , Christopherson R. J.
Published: April 2011

Adrenergic receptors mediate effects of catecholamines on physiological processes including protein and energy metabolism. We determined the effects of temperature and feed intake on beta-1 and beta-2 adrenergic receptors (β1 AR and β2 AR) in skeletal muscle of lambs to assess the potential to modify physiological responses through adrenergic receptors. Twenty-four wether lambs received either restricted (R) or ad libitum (A) levels of feed intake, and were exposed to either cold (C; 0 ± 2 °C) or warm (W; 23 ± 2 °C) temperatures, resulting in four experimental treatment groups (WA, WR, CA and CR). At the end of 4 mo the lambs were slaughtered and biceps femoris, semitendinosus and gastrocnemius muscles were harvested for isolation of plasma membrane. Binding of [3H]dihydroalprenolol to crude plasma membrane was used to determine the β AR densities and binding affinities (Kd). The densities of β1 AR were 28.02 ± 4.17, 40.68 ± 2.26, 28.99 ± 4.68 and 55.56 ± 6.05 fmol mg−1 protein for biceps femoris, 29.35 ± 1.49, 35.34 ± 2.59, 28.36 ± 2.94 and 37.89 ± 3.30 fmol mg−1 protein for gastrocnemius, and 22.66 ± 2.66, 31.21 ± 4.65, 21.84 ± 1.81 and 38.62 ± 3.67 fmol mg−1 protein for semitendinosus, for WA, WR, CA and CR, respectively. The Kd values for all groups ranged from 1.7 to 8.5 nM for β1 AR. Feed restriction increased (P < 0.01) the density of β1 AR in both environments but there was no significant effect of temperature. β1 AR densities and binding affinities were significantly higher in biceps femoris than in gastrocnemius and semitendinosus muscles when feed intake was restricted. The densities of β2 AR ranged from 9.0 to 16.0 fmol mg−1 protein. There was no effect of treatments on the density or receptor binding affinity of β2 AR in muscles. It is concluded that feed restriction causes increased density of β1 AR in sheep and that feed restriction could potentially increase the metabolic responsiveness of skeletal muscle to elevated levels of catecholamines. Key words: Catecholamine receptors, skeletal muscle, temperature, feed
Effect of water restriction and environmental temperatures on metabolic rate and physiological parameters in sheep
Authors: Li B. T. , Christopherson R. J. , Cosgrove S. J.
Published: April 2011

The hypothesis that water restriction reduces metabolic rate and contributes to energy conservation of sheep, and induces changes in blood parameters was tested. Four of eight adult sheep were housed in either a warm (24.8 ± 1.5 °C) or cold (0.4 ± 1.2 °C) environment and fed a diet of alfalfa pellets at 1.2 × maintenance. Each sheep was fasted with or without water according to a crossover design. Average heat production (HP) and rectal temperature (Tr) were higher (P < 0.05) in the cold than in the warm. Fasting decreased HP and Tr (P < 0.05). Water restriction had no additional effect on HP and Tr. Fasting and fasting plus water restriction influenced plasma osmolality and creatinine concentration. Plasma creatinine concentration was lower (P < 0.01) and haemoglobin (Hb) concentration higher in the cold than in the warm environment. Hb concentration was increased with water restriction (P < 0.01) in the warm environment. Plasma cortisol concentration was altered by fasting. Packed cell volume (PCV) in blood, plasma volume and plasma aldosterone were not affected by treatments. The results suggest that water restriction, per se, for 3 d does not suppress metabolic rate in sheep below that resulting from fasting alone. Key words: Heat production, sheep, temperature, water restriction
The effect of phosphorus, phytase enzyme, and calcium on the performance of layers fed wheat-based diets
Authors: Scott T. A. , Kampen R. , Silversides F. G.
Published: April 2011

A trial was performed to test the effects of two levels of Ca (3.7 and 4.0%), two levels of available P (0.2 and 0.4% until 55 wk, 0.11 and 0.22% from 55 to 67 wk), and three levels of phytase enzyme (0, 250 and 500 FTU kg−1) on the performance of laying hens fed diets based on wheat and soybean meal. Phytase supplementation had only small effects, likely because the endogenous phytase in the wheat liberated sufficient phytate-bound P to compensate for only marginally deficient levels. In contrast to what has been found with corn-based rations, there were no negative effects of high levels of AP or of enzyme, suggesting that the effect of exogenous phytase was more complex than a simple liberation of phytate P. Endogenous phytase should be considered when formulating rations based on wheat. Key words: Phytase, layers, wheat, phosphorus, calcium
Rapid determination of total CLA concentration in beef fat
Authors: Aldai N. , Rolland D. C. , Kramer J. K. G. , Dugan M. E. R.
Published: April 2011

Conjugated linoleic acid (CLA) has many potential healthful properties, and beef is naturally enriched with CLA. Simple and rapid methods to measure total CLA were investigated to enable sorting of beef carcasses with potential enhanced economic value. Direct alcohol extraction combined with measuring absorbance was simple, accurate and perhaps the most viable method for rapid carcass sorting compared to methods using saponification or methylation followed by extraction. Key words: Beef, fat, conjugated linoleic acid, rapid methods
The effects of turnout date to pasture on cattle weight gain
Authors: Nams V. O. , Martin R. C.
Published: April 2011

The effects of multiple turnout dates on cattle weight gain were assessed in Nova Scotia in 1999 and 2000. Steers and heifers were released into pasture every 1 to 3 d from May 06 to May 28 in 1999 and from Apr. 26 to Jun. 05 in 2000. Cattle turned out to pasture later in the season gained less weight. Turnout date had a similar effect in both years, and 1 d of earlier turnout increased weight by 0.789 kg per animal over the summer. The time for cattle weight to recover after entering the pasture did not vary with turnout date, but it did differ significantly between years, with cattle recovering weight faster in 2000 than in 1999. Rate of weight gain decreased throughout the summer. The results suggest a mechanism for the turnout date effect: that cattle grow fastest on the pasture at the start of the season, and they grow faster on the pasture than in the barn. Thus, the earlier that they are introduced into the pasture, the more time they spend in the pasture during peak weight gain time. Rotational grazing maximizes the effect of turnout date by minimizing potential pasture degradation caused by early turnout. Key words: Pasture, cattle, rotational grazing, recovery period, turnout date, weight gain
Cloning and sequencing of GH, H-FABP and HSP72 genes in yak
Authors: Zhong Jin-cheng , Ma Zhi-jie , Ou Jiang-tao , Zhu Xiao , Liu Sheng-gang
Published: April 2011

The growth hormone (GH) gene, the heart fatty acid binding protein (H-FABP) gene and the heat shock protein 72 (HSP72) gene of the yak (Bos grunniens) were cloned and sequenced. The sequences were compared with those of other animals, and phylogenetic trees were constructed by the NJ (neighborhood joining) method. Results showed that the yak GH gene was composed of five exons (13, 161, 117, 162 and 198 bp) and four introns (248, 225, 229 and 275 bp). The cDNA of GH was a 654 bp nucleotide encoding a putative protein of 217 amino acid (AA) residuals, with a signal peptide of 26 AAs and the mature peptide of 191 AAs. The H-FABP gene was composed of four exons (73, 173, 102 and 54 bp) and three introns (3460, 1892 and 1495 bp). The cDNA was 402 bp encoding a putative protein of 133 AAs. The yak HSP72 gene was an intron-free 1926bp nucleotide, encoding a protein of 641 AAs. The data suggest that the three genes from the yak were highly conserved with other species at the nucleic acid level. The results of the phylogenetic trees reflect the molecular evolution relationship among these species, consistent with the zoological classification. The genetic distance calculated by the nucleotide sequence of the GH gene’s coding region indicated that genetic distances among yak, cattle, gayal and zebu were relatively small, but genetic distances between these four species and buffalo were relatively large. Therefore, it was more reasonable to consider yak, cattle, gayal and zebu as independent species of the genus Bos, while buffalo belongs to another category (Bubalus). Key words: Yak, GH gene, H-FABP gene, HSP72 gene, phylogenetic evolution
Milk production, milk composition, blood composition, and conception rate of transition dairy cows fed different profiles of fatty acids
Authors: Petit H. V. , Benchaar C.
Published: April 2011

A total of 153 lactating Holstein cows averaging 695 kg body weight (standard error = 11) were allotted 6 wk before the expected date of parturition to 51 groups of three cows blocked for similar calving dates to determine the effects of feeding different profiles of fatty acids from 6 wk before calving on feed intake, milk production and composition, conception rate, and embryo mortality in the subsequent lactation. Cows within each block were assigned to one of the three isoenergetic total mixed diets based on either whole flaxseed (FLA), Megalac® (MEG) or micronized soybeans (SOY). Diets were fed for ad libitum intake from 6 wk before calving to day 50 of pregnancy for pregnant cows, or 120 d postpartum for those not diagnosed pregnant after artificial insemination (AI). Diet had no effect on prepartum dry matter intake but postpartum intake was 9% higher for cows fed FLA than for those fed MEG or SOY. Milk production and fat concentration were similar among treatments. Conception rate at first AI was higher for cows fed FLA (54.3%) than for those fed SOY (26.9%). Conception rate at first AI was similar for cows fed FLA and MEG and it was similar for those fed MEG and SOY. Cows fed MEG tended to have higher embryo mortality than those fed FLA (41.7 vs. 10.5%, P = 0.06) and SOY (41.7 vs. 0%, P = 0.08) at first AI and there was no difference among treatments at second AI. Total embryo mortality was similar for cows fed FLA and SOY but cows fed MEG had higher total embryo mortality than those fed SOY (35.3 vs. 9.1%) and there was a trend (P = 0.07) when MEG was compared with FLA (35.3 vs. 9.5%). These data suggest that feeding flaxseed during the prepartum period has little effect on production in the subsequent lactation but could improve fertility of dairy cows. Key words: Dairy, flaxseed, milk production, reproduction, fatty acids
Growth performance, carcass characteristics and pork quality of pigs fed diets containing meal from conventional or glyphosate-tolerant canola
Authors: Caine W. R. , Aalhus J. L. , Dugan M. E. R. , Lien K. A. , Larsen I. L. , Costello F. , McAllister T. A. , Stanford K. , Sharma R.
Published: April 2011

Growth performance, carcass characteristics and pork quality were evaluated for pigs fed barley and wheat-based diets, which included meal from conventional or transgenic glyphosate-tolerant (Roundup-Ready®) canola. One hundred and forty-four pigs (72 gilts and 72 barrows) weighing 30 ± 3 kg were assigned, three to a pen, on the basis of gender and weight to receive one of four dietary treatments formulated using canola meal from two commercial sources (COM1 and COM2), non-transgenic parental control (PCC) or transgenic (RRC) canola. Pigs were fed a grower diet (75 g kg-1 canola meal) until 60.5 ± 4.0 kg and then a finishing diet (150 g kg-1 canola meal) to 108.6 ± 7.3 kg at slaughter. Pigs receiving the COM1 and COM2 diets had an overall higher (P < 0.0001) daily feed intake (DFI) compared with pigs fed the PCC and RRC diets. Corresponding average daily gain (ADG) was also increased (P = 0.02) for COM1-fed pigs, although feed conversion efficiencies (FCE) of the pigs were similar (P > 0.05) among diets. Gilts had lower overall DFI (P < 0.0001), ADG (P < 0.0001) and FCE (P = 0.04) compared with barrows. Pigs receiving the PCC and RRC diets had heavier (P = 0.002) liver weights than those pigs fed the COM1 and COM2 diets (2.06 and 2.05 kg vs. 1.95 and 1.96 kg, respectively). Postmortem decline in pH and temperature of the longissimus thoracis (LT) muscle from pigs were not different (P > 0.05) among the dietary treatments. Characteristics of pork quality for the LT muscle, which included objective colour and shear force were also not affected (P > 0.05) by dietary source of canola meal. Gross composition of commercial pork cuts were similar (P > 0.05) among the dietary treatments with the exception of small differences for intermuscular (P = 0.04) and body cavity (P = 0.02) fat in the picnic cut and body cavity (P = 0.02) fat in the loin cut. Differences in DFI, ADG and liver weights of the pigs may be related to higher content of antinutritional glucosinolates (µmoles g-1) in the PCC (20.20) and RRC (15.04) varieties compared with COM1 (7.55) and COM2 (7.46) sources of canola meal. Key words: Transgenic canola, growth, pork quality, pigs
Outcome of Bt transgenes and protein in corn silage, processed grains, and rumen content
Authors: Tremblay G. F. , Laberge S. , Castonguay Y. , Chiquette J. , Ouellet D. R. , Delaney S. , Petit H. V. , Michaud R.
Published: April 2011

The environmental impact of transgenic plants has been questioned due to the potential persistence of proteins encoded by transgenes and horizontal gene transfer from the plant to gut microbes. The outcome of the encoded Bt [cry1A(b)] protein and transgene fragments (CaMV-35S, cry1A(b), bar, and bla) was monitored in silage and processed grains of two commercial Bt11 (NK N44-P4 Bt LL and NK N27-M3 Bt LL) and one Bt176 (Elite N09-K9 Bt) corn hybrids. The three Bt-corn hybrids with their non-Bt isolines were field-grown in four replicates. Seven 1.4-kg capacity mini-silos were prepared per plot and then opened after 1, 2, 4, 8, 16, 32, and 64 d. For each hybrid, two 500-kg plastic bag silos were also prepared, sampled after 30 and 198 d, and used in a feeding trial. In the mini-silos, the transgene fragments could no longer be amplified 32 d after ensiling. In the 500-kg plastic bag silos, the transgene fragments were still detectable in the three Bt hybrid silages 30 and 198 d after ensiling. At ensiling, the Bt protein concentration was 2.69, 4.11, and 0.83 µg g-1 DM for the Bt hybrids N44-P4, N27-M3, and N09-K9, respectively. After 64 d of fermentation in the mini-silos, the concentration was 4, 2, and 1% of the initial concentration, respectively, but was 16, 9, and 9% after 198 d in the 500-kg silos. After stringent processing treatments, transgene fragments, except the bla gene fragment, could still be amplified from corn grains. The Bt protein concentration in corn grain of the three Bt hybrids (initially 61, 239, and 21 ng g-1 DM, respectively) decreased by 35, 74, and 67%, respectively, after micronization, by 92, 98, and 89% after extrusion, and by 100% after flaking. After 7 d of feeding Bt corn silage to six dairy cows, Bt protein increased in ruminal digesta with higher concentrations for Bt11 hybrids than the Bt176 hybrid; in all cases, however, concentrations were very low in forage digesta and below detection levels in rumen fluid. Key words: Transgenic maize, silage, processed grains, genetically modified plants, Bacillus thuringiensis endotoxin
Productivity and aggression at grouping of grower-finisher pigs in large groups
Authors: Samarakone Thusith S , Gonyou Harold W
Published: April 2011

A total of eight 11-wk trials were conducted to evaluate the productivity and aggression at grouping of grower-finisher pigs [initial body weight (BW) = 31.8 ± 5.4 kg (mean ± SD), n = 2304] in two group size treatments (18 and 108 pigs pen-1). Pigs were housed on fully-slatted floors, provided one wet/dry feeder space for every nine pigs, and a floor space allowance of 0.76 m2 pig-1 in both group sizes. The level of aggression at grouping was recorded for 2 h starting 0, 24 and 48 h following grouping into small and large groups. Pigs were weighed on weeks 0, 2, 5, 7 and 11, and average daily gain (ADG) was obtained. Average daily feed intake (ADFI) was recorded during two periods (weeks 2 to 5 and 7 to 11). There was no difference in percentage of time spent on aggression between two group sizes up to 48 h following grouping. ADG for the entire 11-wk trial was affected (2%) by large group size (0.971 and 0.955 kg d-1 for groups of 18 and 108, respectively; P < 0.05). However, the greatest effect on ADG was observed during the first 2 wk following grouping (0.919 and 0.833 kg d-1 for groups of 18 and 108, respectively; P < 0.001). There were no significant effects due to group size on ADFI, feed efficiency, variability in final BW within a pen, carcass traits or mortality and morbidity (P > 0.05). In summary, the overall productivity and aggression at grouping did not differ substantially between group sizes of 18 and 108 pigs pen-1. Key words: Large groups, grower-finisher, pigs, productivity, aggression
Cryopreservation of germplasm from chickens kept in Canadian research institutions
Authors: Silversides F. G. , Song Y. , Renema R. , Rathgeber B. R. , Classen H. L.
Published: April 2011

Twenty-three genetically distinct lines of chickens are maintained as living populations by Agriculture and Agri-Food Canada and Canada’s eight Faculties of Agriculture. Historically, cryogenic storage of avian genetic material has been difficult, but we have developed techniques of gonadal transplantation to allow recuperation of stored genetic material into living birds. Gonads from 1660 day-old chicks or late-term embryos (810 females and 850 males) from 18 chicken populations from four Canadian institutions were harvested and cryopreserved using dimethylsulfoxide as a cryoprotectant. Future efforts will be directed to completing the collection of the populations kept in Canadian publicly-funded institutions that conduct agricultural research. Key words: Chicken, genetic resources, cryopreservation, gonads
Developmental patterns in hormone and lipid metabolism of growing Jinhua and Landrace gilts
Authors: Miao Zhi-Guo , Wang Lei-Jie , Xu Zi-Rong , Huang Jin-Feng , Wang Yan-Rong
Published: April 2011

The aim of the present study was to investigate the developmental patterns of lipid metabolism, hormones and growth factor in Jinhua and Landrace gilts. Six purebred gilts of each breed were selected and slaughtered for analyses at 35, 80, and 125 d of age, respectively. Jinhua gilts contained less lean meat (P < 0.01), and more carcass fat (P < 0.05) compared with Landrace gilts. Serum leptin, insulin-like growth factor I (IGF-I) and insulin levels increased with age, whereas, free triiodothyronine (FT3) and free thyroxine (FT4) levels decreased with age in both breeds (P < 0.05). Jinhua gilts had lower (P < 0.05) serum IGF-I, FT3 and FT4 levels, and higher (P < 0.05) serum leptin and insulin levels compared with Landrace gilts. Fatty acid synthase (FAS) activity of Jinhua gilts was higher than that of Landrace gilts (P < 0.001), whereas Jinhua gilts had lower hormone-sensitive lipase (HSL) activity (P < 0.001). Jinhua gilts had lower (P < 0.05) levels of free fatty acid (FFA) and triacylglycerol (TG). These results suggest that hormone and growth factors could induce changes in lipid metabolism that inhibit fat synthesis through reducing lipogenic enzymes activities and promote fat degradation by increasing HSL activity, and therefore induce differences in carcass characteristics in the two breeds. Key words: Gilts, lipid metabolism, carcass characteristics, hormone, growth factor
Potential to double-crop plastic mulch
Authors: Waterer Doug , Hrycan William , Simms Theresa
Published: April 2011

Double-cropping of plastic (polyethylene) mulches has the potential to increase the cost-effectiveness while reducing the environmental impact of this technology for enhancing growth of vegetable crops. In regions with a short growing season, double-cropping of soil mulches hinges on being able to leave the plastic in the field over winter. This extended exposure to the elements may alter the physical and optical characteristics of the mulch, thereby influencing crop productivity in the second year of use. This study evaluated the physical characteristics and efficacy of black, clear and infrared transmitting (IRT) mulches over two cropping seasons in Saskatchewan. The crops planted were pepper (Capsicum annuum) and cucumber (Cucumis sativus) in the first year and tomato (Lycopersicon esculentum) in the second year. Early-season soil temperatures appeared highest under the clear mulch in the first year, but once the crop canopy was established there was little difference in soil temperature among plots having different mulches. Higher yields of both cucumber and pepper were produced in the first year by clear mulch than by black mulch or without mulch. All mulches were still physically sound at the end of the first growing season, but light transmission through the clear and IRT mulches was reduced relative to new mulch. Much of this change was due to soil and other debris on the surface of the mulches. There was little further change in the physical condition or light transmission characteristics of the mulches through the second year of use. Weed growth under clear mulch in its second year appeared to reduce soil temperatures, particularly relative to new clear mulch. Mulch type, either newly laid or year-old, had no impact on yields of marketable tomatoes. More fruit reached full red color prior to harvest in response to clear mulch than to no mulch (bare soil). Yields of marketable tomato fruit obtained on year-old mulch of all types were comparable to yields obtained with new mulch. These data suggest that double-cropping of plastic mulches can be done without loss of crop yield and provide significant savings in materials, labor and disposal costs. While clear mulch was generally the most beneficial for the production of warm season vegetable crops, it did not prevent weed growth in the second year which was problematic. Key words: Wavelength selective, light transmission, cucumber, pepper, tomato
N-alkane profiles of common rangeland species in northern China and the influence of drying method on their concentrations
Authors: Shu Bin , Lin Lijun , Zhang Yingjun , Wang Hai , Luo Hailing
Published: April 2011

Plant wax alkanes have been used as internal markers to estimate diet composition of grazing animals. However, alkane contents in samples may vary depending on the drying method used. This study was undertaken to determine the alkane profiles and concentrations of 17 common range land species in northern China with two different drying methods. The results showed that regardless of drying methods, the odd-chain alkanes, particular C29 and C33, predominated in cuticular wax in all 17 common species and their component plant parts. The alkane patterns of plant species within the same genus were relatively similar and the differences in alkanes between stem and leaf were generally smaller than those between inflorescences and leaf or stem. The influence of drying methods on alkane concentrations varied depending on family and individual alkane. The effect of drying methods on C29 seemed to be smaller than other alkanes in all the samples. The oven-dry method produced higher concentrations (P < 0.05) in the three major alkanes (C23, C31 and C33) in the Gramineae family than the freeze-dry method. Therefore, studies dealing with alkane concentrations should use the same drying method for all samples. Key words: Alkane pattern, steppe grassland, oven-dry, freeze-dry
Effects of ruminal fermentation, intestinal digestion and fecal contact on the survival of Fusarium graminearum on colonized barley grain
Authors: Wang Y. , McLaren D. L. , Scott S. L. , Inglis G. D. , Turkington T. K. , Matic Z. , McAllister T. A.
Published: April 2011

Barley grains were colonized in the laboratory with a mixture of three Fusarium graminearum (FG) strains and processed in five different ways. The survivability of FG on the surface of barley kernels in the rumen, lower digestive tract and after contact with feces was investigated. FG-colonized kernels were placed in nylon bags and incubated in the rumen of three steers for 0, 6, 12 and 24 h. Viability of FG was reduced (P < 0.001) after 6 h and FG was non-viable after 12 h in the rumen. To investigate viability in the lower digestive tract, FG-colonized kernels were placed in nylon bags, passed through the duodenum of three cows and recovered in the feces. No viable FG was found in any of the kernels that passed through the lower digestive tract. FG-colonized kernels were also embedded in cattle feces for 0, 2, 4, 7, 14 and 21 d. FG viability was reduced (P < 0.001) after 2 d and was not detected after 4 d of contact with feces. The likelihood of FG remaining viable after passage through the intestinal tract and excretion in the feces of cattle is exceedingly low. Key words: Fusarium graminearum, barley, cattle, digestive tract, survivability
Response of potatoes to reduced tillage and different nitrogen fertility levels
Authors: Ivany Jerry A , Arsenault Walter , Holmstrom Delmar
Published: April 2011

Conventional tillage in potato production can reduce organic matter levels and cause soil loss. This study compared effects of conventional tillage and zone tillage on plant emergence, weed control, and yield parameters of Russet Burbank potato at nitrogen rates of 0, 50, 100 and 150 kg ha-1. Inconsistent plant emergence across years was likely due to variable weather and planting dates rather than tillage treatment. There were no significant differences between conventional and zone tillage on weed species, weed numbers, weed biomass, or tuber French fry colour. Marketable tuber numbers and total yield were reduced by zone tillage. Nitrogen rate had no effect on any of the variables with the exception that 150 kg ha-1 nitrogen reduced tuber specific gravity compared to the lower rates. Key words: Potato, zone tillage, conventional tillage, nitrogen fertility, tuber number, tuber yield
Genetic structure and proposed conservation strategy for natural populations of Calycanthus chinensis Cheng et S.Y. Chang (Calycanthaceae)
Authors: Fan Chu-Chuan , Pecchioni Nicola , Chen Long-Qing
Published: April 2011

Calycanthus chinensis Cheng et S.Y. Chang, a tertiary relic species in China, is a shade-loving and deciduous bush withan elegant shape and beautiful flower of high ornamental value. It was widely planted in gardens and miniature scapes in China.The objective of this study was to characterize the genetic variation and structure in the three extant populations of the species, in order to provide useful information for a future conservation strategy. Twenty-two of 120 RAPD primers were selected and a total of 257 stable and clear DNA fragments were scored. Calycanthus chinensis showed a lower level of genetic diversity. At the population level, the percentage of polymorphic loci, Nei's gene diversity and Shannon’s information index were 40.9%, 0.1641 and 0.2386, respectively; while at the species level, the corresponding values were 59.1%, 0.2097 and 0.3123, respectively. The estimates of genetic differentiation based on Shannon’s information index (0.2360), Nei’s gene diversity (0.2175) and AMOVA (24.94%) were very similar, and significantly higher than the average genetic differentiation reported in outcrossed spermatophyte. So it suggested high genetic differentiation emerged among populations of C. chinensis. Genetic relationships among populations were assessed by Nei’s standard genetic distance, which suggested that the Tiantai population was genetically distinct from the other two populations. Moreover, the genetic distance was significantly correlated with geographical distance among populations (r = 0.997, t > t0.05). The gene flow (Nm) was 0.8994, indicating that gene exchange among populations was restricted. A conservation strategy was proposed based on the low gene flow and habitat deterioration, which are contributing to the endangered status of this species. Key words: Genetic diversity, endangered plant, population genetics, RAPD
Comparison of different methods for measuring leaf area index in a mixed grassland
Authors: He Yuhong , Guo Xulin , Wilmshurst John F
Published: April 2011

Available LAI instruments have greatly increased our ability to estimate leaf area index (LAI) non-destructively. However, it is difficult to infer from existing studies which instrument has the advantages in measuring LAI over other instruments for grassland ecosystems. The objective of our study was to compare the LAI estimates by two instruments (AccuPAR, and LAI2000), and correlate the LAI measurements to remote sensing data for a mixed grassland. Leaf area index of four grass communities was measured by both the destructive method and instruments. Ground canopy reflectance was measured and further calculated to be LAI-related vegetation indices. Statistical analysis showed that destructively sampled LAI ranged from 0.61 to 5.7 in the study area. Both instruments underestimated LAI in comparison with the destructive method. However, the LAI2000 is better than AccuPAR for estimating LAI. Comparison of four grass communities indicated that the lower the grass LAI, the greater the underestimated percentage of LAI values collected by both instruments. The adjusted transformed soil-adjusted vegetation index (ATSAVI), was the best LAI estimator in the mixed grassland. Key words: Leaf area index, sward structure, nondestructive vegetation sampling, hyperspectral remote sensing, mixed grass prairie
Effect of moisture regimes on combining ability variations of seedling traits in sunflower (Helianthus annuus L.)
Authors: Rauf Saeed , Sadaqat Hafeez Ahmad , Khan Iftikhar Ahmad
Published: April 2011

Seedlings traits provide a reliable and rapid technique for evaluating large numbers of genotypes for abiotic stresses. Experiments on sunflower were carried out under two moisture regimes in controlled conditions to study their modifying effect on phenotypic expression and combining ability of seedling traits such as root length (RL), shoot length (SL), root weight (RW), shoot weight (SW), root-to-shoot ratio (R:S), lateral root number (NLR), lateral root density (LRD), wilting rate index and recovery percent (R%), and their genotypic correlation with achene yield. Variation among breeding lines for relative decrease in the seedling traits under the moisture stress regime indicated their differences in moisture sensitivity. Genetic variation for all seedling traits was low over environments, but high within environments. Moisture regimes modified phenotype, ranking among parents, and combining ability of seedling traits. Relative contribution of specific combining ability to total variation decreased under the moisture stress regime for all root-based traits, with a corresponding increase in general combining ability due to either female, male or both. The moisture stress regime was favourable for the expression of additive genetic variability. All seedling traits except SL showed significant correlation with achene yield, which also signified their importance for improving achene yield under drought regimes. From the breeding point of view, R% and RW were more useful traits for evaluating genotypes for drought tolerance. Key words: Sunflower, seedling traits, genetic variability, drought tolerance
Fertilizer N management and P placement effects on yield, seed protein content and N uptake of flax under varied conditions in Saskatchewan
Authors: Malhi S. S. , Lemke R. , Mooleki S. P. , Schoenau J. J. , Brandt S. , Lafond G. , Wang H. , Hultgreen G. E. , May W. E.
Published: April 2011

In the Canadian prairies, producers prefer to seed and apply all fertilizer nutrients in one operation, but placement of fertilizers at high rates in the seed row can reduce crop emergence. Recently, specialized equipment has been developed to minimize or prevent damage to seedlings by maintaining a safe separation between seed and fertilizer. A 3-yr (2000 to 2002) field study was conducted to determine the effect of N formulation (urea and anhydrous ammonia), placement (broadcast, side-band and mid-row band), timing (fall and spring) and rate (0 to 90 or 120 kg N ha-1), and P placement (7–10 kg P ha-1) on plant density, seed and straw yield, seed protein content, and N uptake in seed and straw of flax (Linum ustatissimum L.) under no-till at four sites (Indian Head, Black Chernozem soil – Udic Boroll; Melfort, Dark Gray Luvisol soil – Mollic Cryoboralf; Swift Current, Brown Chernozem soil – Aridic Boroll; and Scott, Dark Brown Chernozem soil – Typic Boroll) in Saskatchewan. There was a significant increase at 10 of 12 site-years for seed yield, at 5 site-years for straw yield, at 12 site-years for seed protein content, at 11 site-years for seed N uptake, and at 8 site-years for straw N uptake with increasing N fertilizer rate, but the responses were generally small to moderate and varied with placement, form and timing of N application, and placement of P fertilizer in a few cases. Side-banded N fertilizer treatments reduced plant emergence at 3 site-years for urea and at 4 site-year for anhydrous ammonia, but the plant densities were considered adequate for optimum yield. Seed and straw yield, seed protein content, and N uptake in seed and straw were generally similar between side-banded and mid-row-banded N fertilizer, and also similar between urea and anhydrous ammonia in most cases.Occasionally, there was a trend of seed yield reduction with seed-placed P compared with side-banded P, side-banded urea was more effective than broadcast urea, and fall banded N less effective than spring side-banded N. In conclusion, there were few differences in the agronomic performance of urea vs. anhydrous ammonia and side-band vs. mid-row band. The findings did suggest that broadcast urea can be less effective than side-banded urea, fall banded N can be inferior to spring banded N, and seed-placed P can reduce seed yield compared with side-banded P. Key words: Anhydrous ammonia, flax, N application timing, N form, N and P placement, N uptake, protein content, urea, yield
Screening sweet cherry cultivars from the Pacific Agri-Food Research Centre Summerland breeding program for resistance to brown rot (Monilinia fructicola)
Authors: Kappeland Frank , Sholberg Peter L
Published: April 2011

Recently released cultivars and advanced selections of sweet cherries (Prunus avium L.) from the breeding program at the Pacific Agri-Food Research Centre at Summerland, British Columbia, were screened for resistance to brown rot [Monilinia fructicola (Wint.)]. From 2000 to 2003 a range of sweet cherries were inoculated by spraying with a conidial suspension of 1 × 104 colony-forming units per mL of Monilinia fructicola, placed in a growth chamber at 13°C and rated for rot at 8 and 11 d after inoculation. The response of cultivars or selections varied from year to year. In 2000, 10 of 14 cultivars had disease incidences of over 50% by day 8, whereas, in 2002, only 2 of 19 cultivars had disease incidences greater than 50%. Staccato™, Stardust and Sweetheart were in the least susceptible category, that is, the percent rot infection was significantly less than the mean of all genotypes in 2 of the 4 yr. Santina, Skeena, and 13N-07-32 were in the least susceptible category in 1 of 4 yr. The level of resistance to brown rot was not very high. For the least susceptible cultivars such as Staccato™, Stardust, or Sweetheart, the level of resistance was not high enough to grow the crop without fungicide applications. Key words: Prunus avium, resistance, inoculation
Identification of anthracnose resistance genes in dry bean cultivars grown in Manitoba
Authors: Dongfang Yang , Conner R. L. , Yu K. , Balasubramanian P. , Penner W. C. , Yager L. M.
Published: April 2011

Previously described random amplified polymorphic DNA (RAPD) and sequence characterized amplified region (SCAR) markers were used to identify specific genes for anthracnose resistance in 20 dry bean (Phaseolus vulgaris) cultivars and one breeding line. These included six navy bean, five black bean, three kidney bean, two great northern bean, two pinto bean, one cranberry bean, one pink bean and one small red bean cultivars. The reactions of these bean cultivars to five races (i.e., races 23, 31, 73, 81, 105) of Colletotrichum lindemuthianum were used to verify the results of the molecular marker tests. The combined analysis of genotypes estimated with markers and race reactions showed that navy bean cultivar Envoy carried gene Co-12, possibly in combination with other resistance genes, which conferred resistance to all the races except race 105. The bean cultivars Morden003, Messina and CDC Nordic carried Co-15, which provided resistance to only races 73 and 105. Resistance in AC Mariner appeared to be controlled by gene Co-2 either alone or possibly in combination with Co-11. The kidney bean cultivars Chardonnay and ROG 802 carried resistance gene Co-1. Eight other cultivars were resistant to races 23 and 31, which indicated that they carried resistance gene Co-3 or another unidentified resistance gene. Six dry bean cultivars were susceptible to all five anthracnose races. Genotype estimates were based primarily on the virulence pattern of the races on specific cultivars. The results from the molecular tests sometimes supported the proposed genotypes based on the results from the race inoculations, but false positive results often occurred with molecular markers for genes Co-2 and Co-4. Virulence pattern information allowed the detection of specific resistance genes in certain cultivars, but did not always rule out the presence of other genes. Key words: Disease resistance, gene identification, anthracnose (Colletotrichum lindemuthianum), dry bean (Phaseolus vulgaris), molecular marker
Productivity and quality of canola and mustard cultivars under weed competition
Authors: Beckie H. J. , Johnson E. N. , Blackshaw R. E. , Gan Y.
Published: April 2011

Competitive crops or cultivars can be an important component of integrated weed management systems. A study was conducted from 2003 to 2006 at four sites across semiarid prairie ecoregions in Saskatchewan and Alberta to investigate the productivity and quality of canola (Brassica napusL.) and mustard cultivars under weed competition. Four open-pollinated canola cultivars, four hybrid canola cultivars, two canola-quality mustard and two oriental mustard cultivars [Brassica juncea (L.) Czern. & Coss.], and two yellow mustard (Sinapis alba L.) cultivars were grown under weedy and weed-free conditions. When combined across site-years, crop aboveground biomass at maturity and seed yield were reduced by weed interference, except for yellow and oriental mustard. However, seed oil and protein content of cultivars were not affected by weed competition. Among crop types, yellow and oriental mustard were best able to maintain biomass and seed yield under weed interference, followed in decreasing order of competitiveness by hybrid and open-pollinated canola, then canola-quality mustard. Key words: Brassica napus, Brassica juncea, Sinapis alba, weed competition
Hochelaga lettuce
Authors: Jenni Sylvie , Emery George C
Published: April 2011

Hochelaga is an early and heavy crisphead lettuce highly tolerant to bolting under long-day growing conditions (more than 13-h). Hochelaga is the first variety released by the Horticultural Research and Development Centre (HRDC) lettuce breeding program of Agriculture and Agri-Food Canada (AAFC), Saint-Jean-sur-Richelieu, Quebec. Very similar in appearance to Ithaca, the regional standard, Hochelaga is well adapted to organic soils. Hochelaga is more tolerant than Ithaca to rib discoloration, a physiological disorder caused by high-temperature growing conditions. Key words: Lactuca sativa L., crisphead lettuce, rib discoloration, bolting, heat stress, organic soil
Genotype by environment interaction effect on yield and quality of potatoes
Authors: Affleck Ian , Sullivan J. Alan , Tarn R. , Falk D. E.
Published: April 2011

Colour is an important character in the processing of potatoes for French fries. French fry colour is closely associated with sugar content in the tuber. This study examines the stability of yield, sugar content and French fry colour for eight potato cultivars and advanced selections in four environments. Stability was determined using three approaches based on the Eberhart-Russell, Tai and GGE Biplot analyses. The GGE Biplot analysis provided a better characterization of stability than the other two analyses. The most stable and best performing genotypes for both French fry colour and total sugars were Russet Burbank and Umatilla Russet. Cal White had high yield and yield stability but had average stability for poor (dark) French fry colour. The GGE biplot analysis was able to identify mega-environments and those environments which optimized differentiation between genotypes. Both factors are important for the optimization of resources for testing new genotypes. Stability for quality factors in potato can be as important or more important than yield for some processing uses. In this study, genotypes with stability for sugar content and French fry colour were identified and these may be used as parents in breeding for stability. Key words: Potato, yield stability, quality, French fry