bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of including chopped alfalfa hay in barley-based total mixed rations on production and rumen fermentation of lactating dairy cows
Authors: Einarson M. S. , Plaizier J. C. , Wittenberg K. M.
Published: April 2011

Alfalfa silage [13.6% dry matter (DM)] was replaced with chopped alfalfa hay in barley silage and barley-grain-based total mixed rations. This replacement increased DM from 45.2 to 54.9%, decreased physical effective fibre, determined as the proportion of the DM passing through the 8- and 19-mm screens of the Penn State Particle Separator multiplied by dietary neutral detergent fibre (peNDF), from 21.9 to 16.2% DM, increased dry matter intake from 19.1 to 21.2 kg d-1, numerically reduced milk protein yield from 1.01 to 0.93 kg d-1, but did not affect milk yield, milk fat, rumen pH, and rumen ammonia. Key words: Alfalfa silage, chopped alfalfa hay, milk production, feed intake
The responseof plasma leptin and feed intake to growth hormone administration in Holstein calves with different planes of nutrition
Authors: Lee H. G. , Hong Z. S. , Kim M. K. , Kang S. K. , Xu C. X. , Cho J. S. , Seo K. S. , Rho S. G. , Choi Y. J.
Published: April 2011

This study was conducted to observe the effect of the growth hormone (GH)/insulin-like growth factor-1(/IGF-1) axis on leptin and feed intake of 15 Holstein calves in three groups. One group was fed a normal diet (control); the second group, with high nutrition after low feeding with bovine growth hormone (bGH), and a third group, without high nutrition (saline) after low feeding. Each group was intramuscularly (i.m.) injected daily with bovine GH (200 µg kg-1 d-1) or saline solution for 10 d. No significant differences were found in the concentrations of plasma leptin over time for a 24-h period. Plasma leptin was decreased in both saline and GH groups during low and high nutrition regimes, respectively, while IGF-1 levels increased for both nutrition regimes (P < 0.05). With GH treatment during refeeding periods (P < 0.05), leptin levels increased and feed intake decreased; however, the plasma leptin levels slightly decreased with GH treatment during low feeding periods. The plasma IGF-1 concentration increased with GH administration during normal and refeeding periods (P < 0.05). These results indicate that the response of plasma leptin levels to GH varied according to the nutritional condition. In addition, the GH/IGF-1-induced increase in leptin production during the refeeding period may serve as a signal to reduce the feed intake or to increase dramatically after feed restriction in cattle. Key words: Feed intake, growth hormone, leptin, insulin-like growth factor-1, Holstein calves
Measuring and simulating the urination frequency of grower-finisher pigs
Authors: Cortus E. L. , Gonyou H. W. , Lemay S. P. , Barber E. M.
Published: April 2011

Male and female pigs were observed three times during their finishing phase to determine their urination frequency over the course of a day (0.62 ± 0.11 U pig-1 h-1). A single dromedary model is used to describe the daily variation in urination frequency for male and female pigs between 51 and 78 kg. Key words: Urination, grower-finisher pigs, animal activity
Effect of early dietary amino acid restrictions on serum metabolites in pigs selected for lean growth efficiency
Authors: Mule H. R. , Chiba L. I. , Fabian J. , Kuhlers D. L. , Jungst S. B. , Frobish L. T. , Nadarajah K. , Bergen W. G. , Welles E. G.
Published: April 2011

Thirty-two select line pigs for lean growth efficiency and 32 control line pigs (average 20 kg) were used in each of the two experiments to assess the effect of dietary amino acid restrictions during the grower phase on serum cholesterol, triglycerides, total protein, albumin, and glucose concentrations. In each experiment, 16 pens with two gilts and 16 pens with two castrated males per pen were assigned within the genetic line to grower (6.1 or 11.1 g lysine kg-1) and finisher diets (6.1 or 8.9 g lysine kg-1) in a 2 × 2 × 2 factorial arrangement in exp. 1, or grower diets (5.0, 7.0, 9.0, or 11.0 g lysine kg-1) in a 2 × 4 factorial arrangement of treatments in exp. 2. Pigs were offered common finisher diets in exp. 2. Serial blood samples were collected in both experiments. Serum cholesterol at the end of the grower phase was greater in the select line pigs in exp. 1 (P = 0.009) and pigs fed diets low in amino acids in exp. 2 (P = 0.005, 0.026, and 0.039 for linear, quadratic, and cubic, respectively). Serum cholesterol was correlated negatively with lysine intake (r = -0.38; P = 0.039) and serum urea nitrogen (r = -0.39; P = 0.032) in exp. 1 and positively with ultrasound backfat (r = 0.78; P = 0.001) in exp. 2. Serum cholesterol, however, may not reflect the cholesterol content of tissues or pork, except liver. At the end of the grower phase, pigs fed grower diets high in amino acids had greater serum total protein in exp. 2 (P = 0.040 and 0.093 for linear and quadratic, respectively) and albumin concentrations in exp. 1 (P = 0.001) and exp. 2 (linear, P = 0.001), and, at the end of the finisher phase, they had greater serum albumin in exp. 1 (P = 0.001) and seemed to have more total protein in exp. 2, even though there was a trend for the grower diet × genotype interaction (P = 0.095). The carryover effects of the grower diet during the realimentation phase seem to be contrary to the expected positive metabolite status of pigs exhibiting compensatory growth after a period of early dietary amino acid restrictions. On the other hand, higher serum total protein in exp. 2 (P = 0.041 and 0.001 at the end of the grower and finisher phases, respectively) and albumin concentrations at the end of the finisher phase in exp. 1 (P = 0.016) and exp. 2 (P = 0.059) in pigs selected for lean growth efficiency may be an indication that pigs utilized amino acids more efficiently for growth and protein accretion. Exploring fully the effect of dietary manipulations and genotypes on serum metabolites is obviously important, and the results of the present research may contribute to the development of the environmentally friendly, optimal feeding strategies for successful and sustainable pig production. Key words: Amino acid restrictions, genotypes, pigs, serum metabolites
Dietary oil rich in polyunsaturated fatty acids for ruminants: Post-ruminal digesta characteristics and their implications on production
Authors: Mir P. S. , McAllister T. A. , Gibb D. J. , Okine E. K.
Published: April 2011

Maximizing the production of ruminants requires high intakes of feeds that are energy dense, therefore feeds that are usually high in starch. Under these conditions there can be significant passage of partially digested feed starch and fibre to the small intestine. These digesta components interact in a manner that can diminish post-ruminal digestion and absorption. However, in ruminants, the effects of digesta composition on causing physical constraints to digestion and absorption, via increased digesta viscosity have not been given adequate consideration. While elevation of digesta viscosity as a means of reducing rate of nutrient absorption and re-absorption of compounds detrimental to health is a valid approach in humans, digesta viscosity may reduce the production potential of livestock. Thus, there is merit in reviewing the feeding strategies that lead to increased viscosity and how its mitigation can be managed through inclusion of oil in ruminant diets. The interactions between digesta composition and the resultant viscosity with digestive physiology and production factors are examined. This review also highlights the associated benefits of dietary oil for ruminants, such as enhancement of bio-active lipids in ruminant products, health benefits directly to the animal, through decreasing incidence of liver abscesses and effects on production and possibly on the environment (reduction of enteropathogenic bacterial shedding and methane emissions). Key words: Ruminant, starch, digesta characteristics, viscosity, cholecystokinin
Enhancing the vitamin content of meat and eggs: Implications for the human diet
Authors: Sahlin A. , House J. D.
Published: April 2011

Enhancing the vitamin content of meat and eggs provides an opportunity to increase the levels of key nutrients-especially those deemed to be at marginal or insufficient levels-in the human diet for optimal health and well-being. In general, enhancement efforts have focussed on developing feeding strategies to achieve optimal vitamin levels in meat and eggs. The definition of an optimal strategy is influenced by factors such as: (1) the efficiency of vitamin transfer into the final product, (2) the impact on animal performance or health, (3) the impact on the quality characteristics of the final product and (4) economic considerations. Vitamins are an extremely diverse class of nutrients in terms of their chemical and physical properties. Each vitamin differs with respect to stability during processing, susceptibility to bioconversion within the intestinal tract, digestibility, transport and storage in tissues. It follows that the development of vitamin-enriched meat and eggs will be highly dependent on the interaction of multiple factors. Ultimately, the success of such strategies must be judged against the contributions that the enriched products make to the human diet in terms of vitamin intake and consumer acceptance of the products. Key words: Meat, eggs, vitamin enhancement, bioavailability, dietary reference intakes
The effect of dietary energy concentration and total lysine/digestible energy ratio on the growth performance of weaned pigs
Authors: Oresanya T. F. , Beaulieu A. D. , Beltranena E. , Patience J. F.
Published: April 2011

Amino acids should be defined in relation to dietary energy concentration in diets for young pigs. However, the literature contains diverse estimates of the optimum lysine:digestible energy (DE) ratio for weanling pigs performing at levels commonly observed in commercial practice. Further, there is a poor understanding of the reponse of the weanling pig to dietary energy concentration. A growth experiment was conducted to define the optimum total lysine:DE ratio for pigs from 4 to 8 wk of age. Dietary treatments were arranged as a 2 × 5 factorial: low (LDE, 3.4 Mcal kg-1) or high DE (HDE, 3.6 Mcal kg-1) and the following total lysine:DE ratios: 3.7, 4.0, 4.3, 4.6, or 4.9 g Mcal-1). The experiment ran for 28 d, beginning 7 d post-weaning, using four pigs per pen and six pens per diet for a total of 240 pigs (27 ± 2 d; 7.5 ± 1.1 kg). No DE × lysine:DE ratio interactions were detected for any performance parameter (P > 0.05). The average daily feed intake (ADFI) was 4% greater with pigs on LDE than HDE diets (DE,P < 0.05), but was not affected by lysine:DE ratio (P > 0.05). Conversely, DE did not affect average daily gain (ADG) (P > 0.05), but increased quadratically (day 0 to 14; P < 0.05) and (day 0 to 28; P < 0.10) with increasing lysine:DE ratio. Feed efficiency increased linearly with increasing lysine:DE ratio (P < 0.05) and was 4% greater with the HDE than LDE diets (P < 0.05). The optimum total lysine:DE ratio for ADG was determined to be 4.46 and 4.27 g Mcal-1 for pigs between 7.5 to 13 kg and 7.5 to 22.5 kg BW, respectively. Key words: Pig, total lysine, digestible energy, growth
The effects of phytase supplementation on nutrient digestibility, plasma parameters, performance and carcass traits of pigs fed diets based on low-phytate barley without inorganic phosphorus
Authors: Thacker P. A. , Rossnagel B. G. , Raboy V.
Published: April 2011

A total of 80 crossbred pigs (25.5 ± 2.6 kg) were assigned to one of eight dietary treatments. A positive control, based on Harrington barley, was formulated to meet requirements for total phosphorus. Three experimental diets (low in total phosphorus) were formulated based on either Harrington barley (0.28% phytate phosphorus) or the low phytate genotypes LP422 (0.14% phytate phosphorus) and LP 635 (0.09% phytate phosphorus). The four diets were fed with and without 1000 FTU kg-1 phytase. Calcium and phosphorus digestibility were significantly higher (P < 0.05) as a result of supplementation with phytase. For the barley diets formulated without dicalcium phosphate, calcium digestibility averaged 69.6, 73.3 and 72.2% while phosphorus digestibility averaged 36.5, 50.5 and 57.7% for pigs fed the Harrington, LP 422 and LP 635 diets, respectively. The addition of phytase to the diet consistently reduced the percentage of phosphorus excreted in feces and fecal phosphorus excretion declined as the level of phytate in the barley declined. The addition of phytase tended to improve weight gain (P < 0.10) and significantly improved feed conversion (P < 0.05). For pigs fed the barley diets formulated without dicalcium phosphate, daily gain averaged 0.90, 0.99 and 1.01 kg d-1 while feed conversion averaged 2.70, 2.39 and 2.38 for the Harrington, LP 422 and LP 635 diets, respectively. The overall results of this experiment indicate that the performance of pigs fed diets containing low-phytate barley formulated without a source of inorganic phosphorus is at least equal to that of pigs fed diets containing normal-phytate barley and inorganic phosphorus. In addition, the increased availability of organic phosphorus reduced the amount of phosphorus excreted thus reducing the amount of phosphorus that can potentially pollute the environment. Key words: Low phytate barley, phytase, pigs, performance, digestibility
Growth, pork quality, and excretion characteristics of pigs fed Bt corn or non-transgenic corn
Authors: Custodio M. G. , Powers W. J. , Huff-Lonergan E. , Faust M. A. , Stein Jeff
Published: April 2011

Two experiments (exp. 1 and exp. 2, respectively) were conducted to compare performance, pork quality, and excretion characteristics of pigs fed diets containing Bt 11 (Bt) or control corn (C: non-transgenic inbred lines for exp. 1, and a non-transgenic isoline for exp. 2). Experiment 1 involved barrows and gilts (total n = 64; initial BW = 64 kg and 60 kg), while in exp. 2, 120 barrows were used (initial BW = 17 kg). Pigs were allocated to pens, blocked by sex and BW. Isocaloric, isolysinic diets contained an indigestible marker in exp. 1. Feed disappearance and weight gain data, and excreta samples were collected weekly in exp. 1. Feed disappearance and weight gain data were collected weekly in exp. 2. No difference in ADG was observed, however, feed efficiency was greater for pigs fed the C diet. No corn effects were observed for hot carcass weight, loin eye area, or backfat depth. Hunter color ‘b’ values and values for chroma were significantly greater for pigs fed C diets (P = 0.02, < 0.01, respectively) in exp. 1. In contrast, Hunter color ‘b’ values were significantly lower for pigs fed C diets (P = 0.05) in exp. 2. No corn effects were observed for proximate analyses of meat samples, N or P content of fecal and urine samples, nor N digestibility. Pigs fed C diets had greater apparent P digestibility (57.8% vs. 40.2%; P < 0.0001). Key words: Bt corn, animal performance, excretion
Influence of feeding level and dietary oil supplementation on apparent ileal and total tract digestibilities of phosphorus and calcium in pigs fed low-phosphorus diets supplemented with microbial or wheat phytase
Authors: Steiner Tobias , Mosenthin Rainer , Greiner Ralf
Published: April 2011

Two experiments were conducted with pigs fitted with simple T-cannulas at the distal ileum to evaluate the effect of energy (ME) intake implemented by variation of feeding level (FL) (exp. 1) or dietary plant oil content (exp. 2), on apparent ileal (AID) and total tract digestibilities (ATTD) of phosphorus (P) and calcium (Ca), including measurements of lower myo-inositol phosphates at the ileal and fecal level. In exp. 1, 14 barrows (BW 7.3 kg) were fed one of two low-P corn-soybean meal diets providing either 600 U kg-1 microbial (Natuphos® 5000 G) or native wheat phytase at two FL (2.0 vs. 2.8 × ME maintenance requirement) according to a two-period cross-over design. The AID and ATTD of P and Ca were higher (P < 0.05) in pigs fed microbial phytase compared with wheat phytase. Furthermore, the recoveries of lower myo-inositol phosphates in the feces, but not in the ileal digesta, were higher (P < 0.05) when microbial instead of wheat phytase was added to the diet. Increasing the feed intake improved (P < 0.05) overall AID and ATTD of P, independent of the origin of the supplemental phytase. Additionally, the increase in FL improved (P < 0.05) AID of P in pigs fed wheat phytase. There was no effect (P > 0.05) of FL on ileal or fecal recovery of myo-inositol phosphates. In exp. 2, eight barrows (BW 20.3 kg) were fed a low-P corn-soybean meal diet providing 600 U kg-1 microbial phytase (Natuphos® 5000 G) supplemented without or with 6% plant oil according to a two-period cross-over design. There was no effect (P > 0.05) of oil supplementation on AID and ATTD of P or Ca. In conclusion, an increase in FL improves AID and ATTD of P in pigs fed diets supplemented with microbial or wheat phytase, while increasing energy density had no effect. Key words: Feeding level, phytase, phosphorus, calcium, pigs, digestibility
Effect of feeding sunflower seeds on the performance, carcass characteristics, meat quality, retail stability and sensory characteristics of pasture-fed and feedlot finished beef
Authors: Basarab J. A. , Aalhus J. L. , Shah M. A. , Mir P. S. , Baron V. S. , Dugan M. , Okine E. K. , Robertson W. M.
Published: April 2011

This study examined the effects of whole sunflower seed (WSS) supplementation on production parameters, carcass traits, and organoleptic characteristics of beef from steers slaughtered directly off pasture or after receiving a finishing diet. Ninety-six yearling steers (410 kg; SD = 44 kg) were randomly allocated to three pasture (P) dietary treatments: (1) supplemented with 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 during the summer and consumed WSS and BAR at a rate of 0.75 and 1.79 kg head-1 d-1, respectively. At the end of summer grazing half the steers from each pasture dietary treatment group were moved to a feedlot (F) where they were fed high barley-based finishing diets. The remaining 48 steers continued with their dietary treatments 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 mix on a dry matter (DM) basis; F-CON] or a F-WSS diet (68% rolled barley, 15% WSS, 10% alfalfa hay, 5% barley silage, 1% molasses and 1% vitamin/mineral mix on a DM basis) for a further 94 d until slaughter. Supplementation of BAR on pasture increased average daily gain (ADG), while supplementation of WSS had no effect on ADG compared with no supplementation (0.73 vs. 0.58 vs. 0.55 kg d-1, P = 0.023). Inclusion of 15% WSS in the finishing diet decreased ADG (1.46 vs. 1.72 kg d-1, P = 0.038), dry matter intake (DMI) (11.6 vs. 12.6 kg d-1, P = 0.058) and had no effect on feed to gain ratio (8.0 vs. 7.4 kg d-1, P = 0.160). Provision of WSS on pasture or in finishing diets had no effect on carcass traits and organoleptic characteristics of beef from steers slaughtered directly off pasture or after receiving a finishing diet. Slaughtering steers directly off pasture, regardless of pasture dietary treatment, adversely affected most carcass merit, meat quality and retail appearance and acceptability parameters compared with steers finished on a high-barley grain diet. These results indicate that increasing the dietary polyunsaturated fatty acids threefold in the pasture dietary treatment or greater than eightfold in the finishing diets had a small negative effect on animal growth rate and no adverse effect on carcass merit, meat quality and retail acceptability. Key words: Polyunsaturated fatty acids, retail acceptability, beef cattle
A DdeI PCR-RFLP detecting genetic variation of goat POU1F1 gene
Authors: Lan X. Y. , Pan C. Y. , Chen H. , Lei C. Z.
Published: April 2011

We described a DdeI PCR-RFLP method for detecting silent allele at goat POU1F1 locus: p.S241S. Frequencies of D1 allele varied from 0.600 to 1.000 in eight Chinese native breeds. Association of DdeI RFLP genotypes with milk yield of dairy goat was significant (P < 0.05). Key words: Goat, POU1F1 gene, polymorphism, association, milk yield
Influence of dietary methionine to methionine plus cysteine ratios on nitrogen retention in gilts fed purified diets between 40 and 80 kg live body weight
Authors: Gillis A. M. , Reijmers A. , Pluske J. R. , de Lange C. F.M.
Published: April 2011

The relationship between the ratio of available methionine (MET) to methionine plus cysteine (TSAA) intake and wholebody protein deposition (PD) was established using the nitrogen (N) balance technique in gilts between 40 and 80 kg live body weight (BW), according to a repeated 5 × 5 Latin square design. Pigs were fed casein- and cornstarch-based diets that supplied equal moles of TSAA supporting a PD of approximately 80% of the gilts’ PD potential. On a weight basis, the target ratios of MET to TSAA were 42, 47, 52, 57 and 67% for the five experimental diets, respectively. This calculated to 37, 42, 47, 52 and 62.5% on a molar basis. Total N excretion (urine plus feces) was reduced (linear; P < 0.001) and PD was increased (linear; P < 0.001) when the available MET to TSAA ratio was increased to 52%; these values did not change (P > 0.05) when the MET to TSAA ratio was further increased. A number of statistical models were fitted to the data to establish the best fit of the model parameters. The greatest proportion of the variation (R2 = 0.990) was explained with an asymptotic model; based on this model the optimum available MET to TSAA ratio (supporting 90% of the asymptotic value for PD) was 55% on a weight basis or 50.5% on a molar basis. The results indicate that the minimum contribution of available MET to TSAA requirements of growing pigs is higher than the value currently suggested by the National Research Council (46 to 48% on a weight basis). Key words: Methionine, cysteine, pigs, nitrogen balance, protein, deposition
Mammary gland involution and endocrine status in sows: Effects of weaning age and lactation heat stress
Authors: Farmer C. , Knight C. , Flint D.
Published: April 2011

The effects of lactation length and/or heat stress on endocrine status of sows and indicators of mammary involution at weaning were studied. Twenty-eight first parity Yorkshire × Landrace sows were housed at 21 (CTL) or 29°C (HS) throughout lactation. Within each temperature group, half the sows were randomly assigned to a weaning age of 22 (W22: CTL, n = 7; HS, n = 8) or 44 d (W44: CTL, n = 6; HS, n = 7). Litter size was standardized to 10 or 11 on day 2 and to 9 on day 23 of lactation. Blood and milk samples were collected on days -1, 1, 2 and 3 relative to weaning (day 0). Concentrations of prolactin, IGF-I and lactose were measured in both fluids and concentrations of Na, K and IGFBP-5 were measured in milk. Standard milk composition was also determined. Lactose was lower (P < 0.001) and protein greater (P < 0.05) in all milk samples from W44 compared with W22 sows. Percentages of milk fat and dry matter were lower (P < 0.05) in W44 than in W22 on days 2 and 3 post-weaning. Milk lactose was reduced (P < 0.05) with heat stress on days 2 and 3. The day before weaning, concentrations of prolactin in blood (P < 0.001) and lactoserum (P < 0.01) were lower and those of IGF-I in lactoserum were greater (P = 0.01) in W44 than in W22. Values of IGFBP-5 in milk were drastically lower (P < 0.001, more than a fourfold difference), those of Na greater (P < 0.001) and those of K unchanged (P > 0.1) for W44 compared with W22. Post-weaning, evidence of leaky tight junctions (increased milk Na, decreased K) was evident a day earlier (2 vs. 3) in W44 compared with W22 and was most marked in HS. In support, plasma lactose concentrations increased transiently on the same day in HS W44. The greater Na/K ratio in W44 compared with W22 taken together with increased plasma lactose particularly in HS shows that mammary epithelial cell tight junctions become leaky as lactation advances. Weaning age therefore has an impact on milk variables which are indicative of the status of mammary involution in sows and some of these effects are exacerbated by heat stress. Key words: Heat stress, lactation length, mammary involution, sows, weaning
The effect of dietary linola oil on CLA and other fatty acids in bovine milk
Authors: Doepel L. , Toronchuk G. P. , Crowe J. R. E.
Published: April 2011

To evaluate the effects of fat source on milk fat composition and milk conjugated linoleic acid (CLA) concentration, cows were fed diets that were high in either C18:2 or C18:0. Twenty-two Holstein cows were blocked by parity and milk production and randomly assigned within block to one of two dietary treatments containing either 3% pork fat (LARD) or 3% linola oil (OIL) on a dry matter (DM) basis. The diets were fed for 21 d. Feed intake and milk and milk component yields were unaffected by treatment, whereas milk fat percent was decreased with the linola oil treatment. The cis-9, trans-11 CLA concentration of milk from cows fed linola oil was significantly higher than from cows fed pork lard. Key words: CLA, fatty acids, linola oil, milk
The SF6 tracer technique for measurements of methane emission from cattle – effect of tracer permeation rate
Authors: Pinares-Patiño C. S. , Machmüller A. , Molano G. , Smith A. , Vlaming J. B. , Clark H.
Published: April 2011

Previous experiments have suggested that estimates of methane (CH4) emissions from ruminant animals made using the sulphur hexafluoride (SF6) tracer might be influenced by the permeation rate of SF6 (PR). This study examined the latter issue with cattle. For this, analyses of data sets from two grazing trials involving large herds (exps. 1 and 2) and a specifically designed controlled trial (exp. 3) were conducted. Individual daily CH4 emissions from 296 (exp. 1) and 388 (exp. 2) Friesian × Jersey cows in mid-lactation were measured with herds subdivided into four (exp. 1) or five (exp. 2) measurement groups and dry matter intake (DMI) estimated by energy metabolism algorithms. The ranges of tracer PR in exps. 1 and 2 were 2.624–5.689 and 2.214–3.594 mg d-1, respectively. Experiment 3 was conducted using 12 rumen-fistulated beef steers pen-fed on lucerne silage and design arranged as a 4 × 4 Latin square with three replications. Permeation tubes with four levels of nominal PR (three tubes each): low (L), medium (M), medium-high (MH) and high (H) were randomly assigned to four rumen deployment sequences (L-M-MH-H, H-MH-M-L, MH-L-H-M and M-H-L-MH). The grazing experiments revealed a positive effect of PR on the CH4 emission estimates (1 mg SF6 d-1 accounting for 0.6–2.3 g kg-1 DMI), but this effect was significant (R2 = 0.06–0.23, P < 0.05) only when there was a large range in PR (exp. 1), whereas with a narrower PR range (exp. 2) the effect was not significant (R2 < 0.04, P > 0.05). Experiment 3 revealed that the influence of PR upon CH4 emission estimates was linear. It is concluded that despite an influence of PR on CH4 emission estimates, accuracy and precision of the tracer technique is warranted provided that PR are used in a narrow range and balanced between the experimental treatments. Key words: Methane, permeation rate, SF6 tracer, cattle, variation
Delayed harvest affects mineral and NDF concentrations, and digestibility of timothy
Authors: Pelletier S. , Tremblay G. F. , Bélanger G. , Seguin P. , Drapeau R. , Allard G.
Published: April 2011

A 1-wk delay after late heading in the harvest of timothy spring growth reduced dietary cation-anion difference (-17%), in vitro digestibilities of dry matter (-7%) and neutral detergent fiber (-10%), and increased neutral detergent fiber concentration (+5%). In summer regrowth, the harvest delay tended to have similar effects, but variations (1-6%) were smaller. Key words: Nutritive value, stages of development, Phleum pratense L., metabolic disorders
Effects of water and nitrogen on seed production of creeping red fescue
Authors: Fairey N. A.
Published: April 2011

In order to address a paucity of information, a study was conducted in the Peace River region of northwestern Canada to determine the effects on seed production of creeping red fescue (Festuca rubra L. var. rubra) of six water treatments [natural precipitation and 100, 125, 150, 175 and 200% of the average, cumulative, long-term precipitation (LTP) of 459 mm yr-1] in combination with four N-fertilization regimes (zero + 102, 34 + 68, 68 + 34, and 102 + zero kg ha-1 N for the first + second crops, respectively). The 2-yr seed yield exceeded 2900 kg ha-1 when N was supplied to just one of the two seed crops, viz. with 150 to 200% LTP when N was applied only to the first seed crop, and with 125 to 150% LTP when N was applied only to the second seed crop. Under the prevailing, long-term, moisture environment at the study site (100% LTP), total seed yield over two production years was greatest (2136 kg ha-1) with 68 + 34 kg ha-1 N. The effects of the water and N treatments on seed yield were not associated with the mass of root organic matter recovered after the harvest of the second seed crop. These results confirm, and begin to quantify, numerous visual observations in the Peace River region that seed yields of creeping red fescue are restricted by insufficient precipitation. Key words: Creeping red fescue, Festuca rubra, grass seed production, nitrogen fertility, water, soil moisture
Time of nitrogen application affects nitrogen use efficiency of wheat in the humid pampas of Argentina
Authors: Barbieri P. A. , Rozas H. S. , Echeverría H. E.
Published: April 2011

Nitrogen (N) fertilization is an important management practice to increased grain yield; however, it is imperative to increase nitrogen use efficiency (NUE) in order to diminish risks of environmental pollution. The objective of this study was to determine the effect of fertilization times on wheat grain yield, grain N accumulation and grain N recovery efficiency (RE) in different sites and years at the south-eastern wheat belt of the Pampas. The experiments were a factorial combination of N rates and fertilization times (sowing and tillering). Grain yield ranged from 1600 to 7900 kg ha-1 and fertilization at tillering increased grain yield compared with fertilization at sowing (5465 vs. 5110 kg ha-1), similar behavior was observed for grain N accumulation (95 vs. 86 kg ha-1) and RE (0.41 vs. 0.32). Predicted grain yield by CERES-Wheat model for different N rates and fertilization times was correlated with observed grain yield (r2 = 0.71). While fertilization at tillering significantly increased grain yield, CERES-Wheat model estimated nitrate leaching losses that ranged from 12 to 62 kg N ha-1 and from 7 to 16 kg N ha-1 for fertilization at sowing and tillering, respectively. However, denitrification losses ranged from 1.2 to 3.9 and from 0.5 to 2.4 kg N ha-1 for fertilization at sowing and tillering, respectively. Leaching losses for fertilization at sowing are a consequence of water excess early in the growing season and would be the main N loss factor. Therefore, N application at tillering is an appropriate strategy to improve NUE in the south-eastern wheat belt of the Pampas. Key words: Wheat, fertilization time, nitrogen use efficiency, N losses, CERES-Wheat
First year growth response of selected hybrid poplar cuttings to root-zone salinity
Authors: Steppuhn H. , Kort J. , Wall K. G.
Published: April 2011

Cuttings from four hybrid poplar clones (Walker, CanAm, Manitou, and Assiniboine) used in plantations and windbreaks on the Canadian Prairies were evaluated in their response to sulphate-based, root-zone salinity at Canada’s Salt-Tolerance Testing Facility. Vernalized, hardwood cuttings were planted in inert sand flushed four times daily with salinized, nutrient hydroponic solutions ranging in electrical conductivity from 2.2 to 30.9 dS m-1. The response in new growth was measured by the total summed length of new shoot growth, new shoot biomass, and the length of the main stem from its initial point as a bud on the cutting to its terminal tip. Based on these measurements analyzed statistically, Assiniboine cuttings out-performed those from the other clones. At 30.9 dS m-1, none of the cuttings from any clone sprouted new growth. At 21.4 dS m-1, poor growth and considerable dieback characterized all clones. At 13.8, 8.3, and 4.5 dS m-1, all cuttings subjected to root-zone salinity registered less growth compared with those cuttings growing in nutrient-only solutions (2.2 dS m-1), although the Assiniboine cuttings declined least. Based on this experiment, the descending salinity-tolerance order for the hybrid poplar clones tested using first-year growth from hardwood cuttings is: Assiniboine > Walker = CanAm = Manitou. Key words: Sulphate salinity, agroforestry, windbreak, Populus, shelterbelt, hybrid poplar
Integrating climate and trait models to predict the invasiveness of exotic plants in Canada’s Riding Mountain National Park
Authors: Otfinowski R. , Kenkel N. C. , Dixon P. , Wilmshurst J. F.
Published: April 2011

Invasive exotic species threaten the biodiversity and function of native ecosystems. Existing models, attempting to predict successful invaders, often emphasize isolated stages of biological invasions and fail to formalize interactions between exotic species and recipient environments. By integrating the native climatic range and biological traits of exotic vascular plants reported inside and outside Riding Mountain National Park, Manitoba, Canada, we present a model where invasion risk is predicted using the likelihood of establishment and proliferation of exotic species. Exotic vascular plants constituted 11.5% (77/669) of the total vascular flora of Riding Mountain National Park and approximately 14.2% (202/1418) of the flora of Manitoba. Based on their climatic range in Europe, 155 among 174 exotic species absent from the Park, including those found in Manitoba and other natural areas in Canada, were predicted to establish within its boundaries. Among the biological traits of exotic plants, perenniality and vegetative reproduction correctly identified 61% of documented invaders of natural areas in Canada and helped to further define a subset of 40 exotic plants with the highest potential to proliferate within the Park’s natural areas. Among these, 11 are still absent from inside its boundaries and 17 are not yet reported in Manitoba. Our results demonstrate that Riding Mountain National Park and natural areas in western Canada will continue to be impacted by exotic vascular plants. By integrating establishment and proliferation, key stages in the progress of biological invasions, our model offers a synthetic approach to the prediction and management of biological invasions inside natural areas; such integration is critical to the protection of Canada’s endemic biodiversity. Key words: Biological invasions, invasive alien plants, climate-matching model, life history, natural areas, risk assessment
Divergent phenotypic selection for alfalfa cell wall fractions and indirect response in digestibility
Authors: Tecle I. Y. , Hansen J. L. , Pell A. N. , Viands D. R.
Published: April 2011

An alfalfa (Medicago sativa L.) breeding strategy to decrease slowly digestible or indigestible fiber and simultaneously increase digestible fiber could improve forage quality without reducing total fiber. The objectives were: (1) to estimate selection responses from divergent and opposite direction selections of (i) hemicellulose (HEM) and acid detergent fiber (ADF), (ii) acid detergent lignin (LIG) and HEM + cellulose (CEL) and (iii) CEL and HEM + LIG, and (2) to determine correlated responses in in vitro true digestibility (IVTD). Selection progress was evaluated in replicated plot trials at two locations, sampled for 2 or 3 yr. Selection for divergent HEM and ADF resulted in change only for ADF [10.9 g kg-1 dry matter (DM)]. Selection for divergent LIG and HEM + CEL, resulted in same direction change in LIG (3.3 g kg-1 DM). Selection for divergent CEL and HEM + LIG resulted in change only in CEL (5.1 g kg-1 DM). Low LIG and high HEM + CEL, and low ADF and high HEM populations had 9.7 and 8.3 g kg-1 DM higher IVTD than their counterparts, respectively. The first cycle of selection for the fiber components simultaneously in the opposite directions was not successful. However, reduced LIG or ADF concentration appears to increase alfalfa forage digestibility and decrease total fiber concentration. Key words: Alfalfa, cell wall, hemicellulose, cellulose, lignin, digestibility
The effect of seeding rate, seeding date and seeder type on the performance of Camelina sativa L. in the Maritime Provinces of Canada
Authors: Urbaniak S. D. , Caldwell C. D. , Zheljazkov V. D. , Lada R. , Luan L.
Published: April 2011

The hypothesis of this study was that spring camelina (Camelina sativa L.) could be grown as a high-value crop under the moist, cool conditions of the Maritime Provinces in Canada and seeding date, seeding rate, and type of seeder will modify productivity and oil composition. The objectives were (1) to determine the optimum seeding date and seeding rate for camelina production in the Maritimes; and (2) to evaluate the effect of seeder type (seed drill and forage seeder) on camelina establishment and seed yield. A seeding date and rate experiment and a seeder type and seeding rate experiment were conducted in 2005 and 2006 in Nova Scotia and Prince Edwards Island. Seeding date did not affect camelina emergence, plant height, seed yield and oil content. The earlier seeding date increased the concentration of stearic acid in the oil compared with the later seeding date. Seed yield of camelina was not affected by seeding rate in the seeder type by rate trial but higher yields were observed up to 600 seeds m-2 in the seeding date by rate trial. The weak yield response to seeding rate could be explained by the high yield compensation ability of camelina through branching. It was suggested that seeding rates in the range of 400 to 600 seeds m-2 would likely be best for camelina grown in the Maritime region. The forage seeder provided a better crop stand compared with the seed drill, although both seeders provided satisfactory crop establishment. Camelina has the potential to be produced successfully in the Maritime Provinces due to its adaptability to seeder type, low seeding rate requirements, and a wide window for seeding date. Key words: Camelina, seeding date, seeding rate, seeder type
Response of irrigated soft white spring wheat to seeding date, seeding rate and fertilization
Authors: McKenzie R. H. , Middleton A. B. , Dunn R. , Sadasivaiah R. S. , Beres B. , Bremer E.
Published: April 2011

Irrigated production of soft white spring wheat (Triticum aestivum L. Em Thell.) (SWSW) for pastry flour or ethanol production is feasible if the high yield potential of recently released cultivars can be realized. Field studies were conducted at three locations over a 3-yr period to determine the response of irrigated SWSW to seeding date, seeding rate and fertilization (N, P and K) in southern Alberta. The highest yield was obtained for the first seeding date (Apr. 20 to 24). Seeding 2 wk later reduced ave rage grain yield by 3%, while seeding 4 wk later reduced average grain yield by 15%. The optimum seeding rate was 200 to 240 viable seeds m-2 (84 to 101 kg ha-1). Maximum yields were achieved when total available N (fertilizer + residual soil NO3-N + mineralized N) was greater than 26 kg N Mg-1 of potential yield. Mineralized N ranged from 45 to 183 kg N ha-1 (mean 125 kg N ha-1). Grain protein concentration did not exceed the maximum allowed for protein premiums (99 g kg-1) when total available N was less than 27 kg N Mg-1 of potential yield. The optimum P fertilizer rate was approximately 13 kg P ha-1 unless extractable soil P was very high. No response to K fertilizer was observed. Maximum grain yields of 7.3 to 10.6 Mg ha-1 were achieved by seeding early with a minimum of 200 viable seeds m-2 and application of sufficient N and P fertilizer. Key words: Triticum aestivum, nitrogen fertilizer, N mineralization, grain protein concentration, phosphorus
Leaf epicuticular wax and glaucousness in Altai wildrye grass: which trait is most important to water status?
Authors: Jefferson Paul G
Published: April 2011

Epicuticular wax (EW) concentration on the outermost layer of the plant cuticle increases in response to drought stress for many xeric plant species. Glaucousness, or the visible (blue) waxiness of leaf surfaces, is associated with greater EW concentration compared with nonglaucous (green) plants of Altai wildrye grass [Elymus angustus (Trin.) Pilger] (AWR). The contributions of EW concentration and glaucousness to drought stress response have been confounded in previous research. The objective of this study was to determine the effects of EW concentration and glaucousness on water relations of AWR. Water loss rate (WLR) of excised leaves was determined for 180 half-sib AWR lines in 1988, 1989 and 1990 at Swift Current, Saskatchewan, Canada. The mean WLR of blue half-sib lines was 36% less than green half-sib lines (P < 0.05). Among blue (n = 60) or among green (n = 60) half-sib lines, however, there was no significant correlation between WLR and EW concentration. Leaf water potential (Ψ) was determined for 10 blue and 10 green half-sib lines in 1988, 1989 and 1990. Predawn leaf Ψ was 18% higher for blue half-sib lines than for green half-sib lines (P < 0.01), but there was no correlation between Ψ and EW concentration within either group of half-sib lines. Four contrasting synthetics were generated by inter-crossing parent plants that had high or low EW production within either phenotype. The EW concentration, forage yield, predawn Ψ, and midday Ψ were determined for these four synthetics for three sampling dates per year from 1996 to 2001. Selection for high and low EW concentration shifted this trait (P < 0.01) by 0.19 g m-2 between glaucous synthetics and by 0.07 g m-2 between nonglaucous synthetics. Glaucous synthetics exhibited improved predawn Ψ by 0.05 MPa and predawn turgor potential (P) by 0.08 MPa (P < 0.05) compared with nonglaucous synthetics. However, selection for high and low EW concentration did not affect predawn Ψ nor predawn P in either glaucous or nonglaucous synthetics. Selection for blue glaucousness in AWR altered water relations, but selection for EW concentration did not. Key words: Forage breeding, range improvement, forage yield, drought stress, water potential, turgor potential, epicuticular wax
Flavour volatile production and regulation in fruit
Authors: Song Jun , Forney Charles F
Published: April 2011

Consumption of fresh fruits is increasing as consumers become more aware of their nutritional value and role in disease prevention. Improving the flavour properties of fresh fruit reaching the consumer would add value, increase consumption, and create new markets for these commodities. One of the important characteristics of fruit ripening is volatile aroma production. Using apples (Malus domestica), strawberries (Fragaria ananassa Duch.) and melons (Cucumis melo L. var. reticulatus Naud; C. melo L. inodorus; C. melo L. cantalupensis) fruit as examples, this review focuses on recent developments in fruit aroma research. Both sensory studies and instrumental analysis confirm the importance of volatile production in fruit and its contribution to eating quality. Sensory analysis should further define the contribution of individual volatile compounds to total flavour quality. Volatile biosynthesis and its contribution to fruit eating quality is very complex, and is influenced by many factors, such as genome, harvest maturity, and postharvest handling and storage. Application of 1-methylcyclopropene (1-MCP) and transgenic lines suppressing ethylene action and biosynthesis demonstrate ethylene involvement in volatile formation and provide useful research tools to elucidate the volatile production process during fruit ripening. Cloning of genes and characterization of enzymes responsible for volatile production helps us to understand the biochemical pathways and control mechanisms. Despite the exciting developments in flavour research, several challenges still remain to be solved. An understanding of the fundamental mechanisms controlling changes in flavour quality is limited, and most biochemical pathways determining this quality trait are still unknown. As part of secondary metabolism, volatile production in fruit is a complex process with tightly controlled systems involving substrates, enzymes and energy from many pathways. It is our hope that the biochemical pathways regulating the synthesis of volatile compounds in fruit will be determined using integrated approaches, including biochemical, genomic, proteomic and microscopy tools to determine fundamental metabolism and its localization. Combining these efforts with direct measurement of sensory properties will lead us to new methods to optimize and retain fruit flavour in the market place. Key words: aroma, fruit ripening, volatile analysis, sensory, apple, strawberry, muskmelon
Dalton alfalfa
Authors: Acharya S. N.
Published: April 2011

Dalton alfalfa (Medicago sativa) was developed by the Agriculture and Agri-Food Canada Research Centre, Lethbridge, Alberta. This cultivar, tested as LRC01CR in western Canada, is derived from parental clones that are both bacterial wilt (BW) and verticillium wilt (VW) resistant. When grown under irrigated and rainfed conditions for forage it out yielded Beaver (check) by 3%, for seed it out yielded Beaver on irrigation by 19%. Dalton is well suited to forage and seed production in western Canada where VW may be of concern. Key words: Cultivar description, alfalfa, Medicago sativa
Effect of planting bed shape, mulch and soil density on root yield and shape in North American ginseng (Panax quinquefolius L.)
Authors: Roy R. C. , Ball Coelho B. R. , Reeleder R. D. , Bruin A. J. , Grohs R. , White P. , Capell B.
Published: April 2011

Ginseng root value varies with shape. To increase understanding of factors affecting root shape and growth, we conducted a 4-yr field experiment with three planting bed shapes with and without straw mulch cover, and 3-yr duplicate experiments with varied soil textures and bulk densities (BD). Panax quinquefolius L. plants either remained undisturbed for 3 yr in vertical tiles where sand or loam soil was compacted to differing BD, or were transplanted into low BD soil after 1 yr. Transplanting aimed to demonstrate the influence of conditions encountered in the first year of growth on mature root shape, and to explore opportunities to manage beds and manipulate root shape in transplanted ginseng, which may be a common practice in future. Without mulch, 4th year root yields were reduced by 65%, primarily due to a 60% reduction in plant stand which occurred by the end of the seedling year. Seeding directly into the ground resulted in yields similar to conventional rounded beds and a greater proportion of roots of favourable shape, likely due to greater soil BD in ground plots than round beds. Relative to low BD, high BD soil resulted in shorter, rounder "chunk" grade roots after 1 and 3 yr growth in situ. After 3 yr, roots were shorter and rounder in loam than in sand. Soil BD effects were not retained after 3 yr for replants, so high BD pre-treatment of transplants will not improve root shape over the longer term. Moderate soil compaction may reduce production of undesirable pencil-grade roots, but there is a yield trade-off with high BD soils. A high BD must be maintained for >1 yr, and a decline in stand is likely in compacted loam soil which has slow drainage. Key words: Root grade, North American ginseng, American ginseng