Several models for simulating the growth and nutritive value of forage crops have been developed ... more Several models for simulating the growth and nutritive value of forage crops have been developed in past decades but most of them are specific to one crop species and focus only on agronomic outputs. In this study, we calibrated and evaluated the performance of the STICS crop model for the simulation of the growth and nutritive value (cell wall concentration and digestibility, in vitro true dry matter [DM] digestibility, and N concentration) of timothy (Phleum pratense L.) under Canadian growing conditions. Equations used for calculating nutritive value attributes were derived from the CATIMO model (CAnadian TImothy MOdel). The calibration included two datasets, one for eastern Canada (cultivar Champ) and one for western Canada (cultivar Climax). Very good agreement between simulations and measurements was obtained for the calibration dataset (RMSE% ≤10% for all variables). Twenty-two datasets including leaf area index (LAI), forage DM yield, N concentration, cell wall concentration and digestibility, and in vitro true DM digestibility were then used to evaluate model performance. The model simulated LAI, forage DM yield, nitrogen concentration and nutritive value of the primary growth fairly well for all sites (RMSE% <30%), but was less successful for the regrowth (i.e. average RMSE of forage DM: 66.5 and 85.9 g m −2 for primary growth and regrowth, respectively). The next step in this research will be to perform, multiannual simulations to evaluate crop reserve simulations and improve regrowth simulation.
The development of short-season hybrids has made corn (Zea mays L.) silage (CS) production possib... more The development of short-season hybrids has made corn (Zea mays L.) silage (CS) production possible in cooler areas. This work aimed at determining biomass yield and nutritive quality of short-season corn CS hybrids. Six corn hybrids were grown in three years at four locations within the Canadian prairies with four field replications. Hybrids were harvested before occurrence of frost at a target dry matter (DM) content of 300 to 400 g kg−1. Corn heat units (CHU) from seeding to harvesting (CHUseed-harv) and water supply were recorded. Samples were analysed for nutrient content; i.e., DM, neutral detergent fiber (NDF), crude protein (CP), starch, and in vitro DM and NDF digestibilities (48 h incubation). Then, CHUseed-harv, water supply, whole plant DM, CHU rating of the hybrid, and cob percentage were assessed as predictors of nutrient content. Location, hybrid, and year affected nutrient composition and yield. Overall, CP and NDF were positively correlated (r = 0.48, p < 0.01), ...
Doce, R. R., Baron, V. S., and Dick, A. C. 2015. Estimating swath-grazed carrying capacity from p... more Doce, R. R., Baron, V. S., and Dick, A. C. 2015. Estimating swath-grazed carrying capacity from plot-scale data. Can. J. Plant Sci. 95: 647–651. A spreadsheet calculator was developed to estimate farm-scale carrying capacities for swath grazing beef cows with forage yield and quality data from small areas within fields or paddocks. It could be used to compare agronomic treatments for swath grazing potential from plot data when combined with existing beef nutrition equations. Examples using either in vitro true digestibility at 30-h digestion or acid detergent fiber (ADF) in equations to estimate digestible energy were compared with actual field-scale carrying capacities to evaluate the ability of the methods to meet requirements of scale, precision and accuracy. Both methods were capable of estimating carrying capacity at a realistic whole-farm scale, but the ADF-based method was superior with respect to accuracy and precision characteristics.
Manafiazar, G., Basarab, J. A., Baron, V. S., McKeown, L., Doce, R. R., Swift, M., Undi, M., Witt... more Manafiazar, G., Basarab, J. A., Baron, V. S., McKeown, L., Doce, R. R., Swift, M., Undi, M., Wittenberg, K. and Ominski, K. 2015. Effect of post-weaning residual feed intake classification on grazed grass intake and performance in pregnant beef heifers. Can. J. Anim. Sci. 95: 369–381. There is limited knowledge of how cattle tested for feed efficiency under drylot conditions perform when they graze on summer pasture. Residual feed intake adjusted for end of test backfat thickness (RFIfat) was determined on 171 beef crossbred heifers under drylot conditions over 2 yr using an automated system. Upon completion of the test, the 10 lowest and 10 highest RFIfat (–0.54±0.17 vs. 0.58±0.15 kg DM d−1) heifers in 2012, and the 14 lowest and 14 highest RFIfat (−0.47±0.16 vs. 0.53±0.19 kg DM d−1) heifers in 2013 were selected and placed on meadow bromegrass pasture to investigate the effect of RFIfat ranking on their grass intake and performance on the pasture. The pasture adaptation period (8 ...
Spring-planted mixtures of spring and winter cereals in a silage/fall pasture system have been sh... more Spring-planted mixtures of spring and winter cereals in a silage/fall pasture system have been shown to extend the grazing season in the Parkland of the Canadian prairies. Experiments were conducted at Lacombe, Alberta to determine the effects of planting date on yield and yield components of spring-seeded spring oat (Avena sativa L.), winter wheat (Triticum aestivum L.), winter triticale (X Triticosecale Wittmack) and winter rye (Secale cereale L.). The cereals were grown as monocrops or as binary mixtures of the oat and winter cereals. Treatments were planted in early May and mid-June and harvested twice for forage. The initial harvest for early and late planting dates occurred when oat reached the early-milk and heading stages, respectively. Regrowth was harvested in mid- to late September. The planting date x treatment interaction did not affect (P ≤ 0.05) annual yield (initial + regrowth) even though oat was harvested at different developmental stages. Averaged over treatments,...
The response in composition, in vitro dry matter digestibility (IVDDM), and enzymatic saccharific... more The response in composition, in vitro dry matter digestibility (IVDDM), and enzymatic saccharification, of alfalfa and various grasses to selective solvent delignification (SSD), as well as the nutritive value of the residual biomass (co-product), was determined. The SSD pretreatment reduced lignin concentrations in grasses but not in alfalfa. Associated effects were increases in concentrations of neutral detergent fiber (NDF) due
larly well adapted for grazing, but are sometimes used for hay in the western parkland of Alberta... more larly well adapted for grazing, but are sometimes used for hay in the western parkland of Alberta (Baron and Grasses adapted to both hay and pasture are lacking in the prairie Knowles, 1984; Knowles and Baron, 1990; Knowles et parkland. 'Regar' meadow bromegrass (Bromus riparius Rhem.), 'Manchar' smooth bromegrass (B. inermis Leyss.), S9044 (a smooth-al., 1993). Meadow bromegrass-smooth bromegrass meadow bromegrass cross), common meadow foxtail (Alopercurus crosses have been made to develop dual-purpose grazpratensis L.), and 'Kay' orchardgrass (Dactylis glomerata L.) were ing/hay type cultivars for the Canadian Prairies evaluated for traits useful in dual purpose grass species at early (late (Knowles and Armstrong, 1984). During the late 1980s May), late (late June), and regrowth (early September) harvests. and through the 1990s, orchardgrass has been grown Herbage, leaf, and stem nutritive value; mass; and leaf/stem ratio were extensively in the more moist areas of Alberta. These determined. Differences among species were related more to herbage genotypes have been compared for seasonal herbage mass and morphology than to leaf and stem quality. Early harvest mass when cut frequently and infrequently (Knowles orchardgrass herbage mass was low at 55% of meadow foxtail (2.9 and Baron, 1990; Knowles et al., 1993), but comprehen-Mg ha Ϫ1). However, stem content of meadow foxtail represented 60% of early herbage mass, limiting its potential. Regrowth mass of sive evaluation of their potential is required to provide meadow bromegrass, S9044, and orchardgrass exceeded 2.5 Mg ha Ϫ1 , improved seasonal utilization. whereas smooth bromegrass and meadow foxtail were as low as 2.1 When characterizing forage potential of grass species Mg ha Ϫ1. Regrowth leaf mass of the former species exceeded 1.9 Mg used for hay and grazing, it is important to evaluate ha Ϫ1. Late herbage mass of smooth bromegrass was always greater traits such as mass, sward structure, plant morphology, than the other species. Leaf acid detergent fiber (ADF) of S9044 and and nutritive value of leaf and stem materials. Defining smooth bromegrass was lower (range 189-242 g kg Ϫ1) than meadow forage quality potential for hay (often initial growth) is bromegrass (range 217-284 g kg Ϫ1). By contrast, late and regrowth relatively simple compared with pasture, since hay can harvest stem ADF of meadow bromegrass was lower (range 237-360 be fed ad libitum in stalls to estimate intake, and digestg kg Ϫ1) than S9044 (range 257-366 g kg Ϫ1). Variation among Bromus types for late and regrowth yield, and leaf fiber may influence manage-ible dry matter intake is directly related to forage qualment strategies. ity. Some selection of leaf material occurs, but most of the entire plant is consumed. Under grazing, the relationships between forage mass, sward structure, and nutritive value are important M atching forage nutritive value and availability with livestock production goals is a challenge, aspects of forage potential. Forage mass and sward especially in areas with short growing seasons. In central structure (leaf/stem ratio, leaf mass, etc.) may influence Alberta, Canada, grass species with regrowth characteranimal intake (Coleman, 1992) and must be taken into istics necessary in intensive pasture management were consideration together with conventional nutritive panot available until the last decade. Species and genorameters. As pasture mass increases animal intake levels types within species with adequate regrowth characterisoff, and forage nutritive value becomes more important tics have been identified and developed during the last than sward structure. The pasture mass at maximum 10 to 15 yr. Examples are meadow foxtail, meadow intake is often obscure, varying from 1.2 Mg ha Ϫ1 of bromegrass, and crosses between meadow and smooth green leaf material in cool-season grasses to 3.5 Mg ha Ϫ1 bromegrass. in warm-season grasses (Coleman, 1992; Forbes and Meadow foxtail and meadow bromegrass are particu-Coleman, 1993; Penning et al., 1994). Also, ruminant animals tend to select leaves instead of stems (Poppi et V.S. Baron and A.C. Dick, Agriculture and Agri-Food Canada, 6000 al., 1980) and select live material instead of dead mate
Regrowth in pastures is critical to economic production in short‐season areas. This study compare... more Regrowth in pastures is critical to economic production in short‐season areas. This study compared regrowth characteristics among three Bromus genotypes and meadow foxtail (Alopecurus pratensis L.) during late summer and fall. Growth analyses were conducted and yield components were determined in ‘Carlton’ smooth bromegrass (B. inermis Leyss.), ‘Regar’ meadow bromegrass (B. riparius Rhem.), an experimental strain (S9044) derived from F2 plants of a smooth ✕ meadow bromegrass cross, and common meadow foxtail. Seven weeks of plant regrowth after severe defoliation were characterized during 1985 and 1986 at Lacombe, AB, Canada (52° 28' N lat). The variation among the three grass species and the interspecific hybrid that was most critical to regrowth yield occurred during the first 21 to 28 d after defoliation. Smooth bromegrass consistently yielded less dry matter (DM) and had lower crop growth rates (CGR) than the other genotypes. Smooth bromegrass seemed limited most by a slowly ...
Currently, there is interest in Western Canada in extending the grazing season using perennial an... more Currently, there is interest in Western Canada in extending the grazing season using perennial and annual forages. Of greatest concern is the environmental sustainability of these grazing systems, with emphasis on their ability to withstand erosion. A study to examine the runoff and sediment yields of annual and perennial forages in central Alberta was initiated in 1994. Runoff and sediment yield were quantified under snowmelt and rainfall events for two seasons. Rainfall simulation was used to further examine runoff under growing season conditions. Four forage treatments (two annuals: triticale and a barley/triticale mixture and two perennials: smooth bromegrass and meadow bromegrass) and three grazing intensities (light, medium and heavy) were studied, each replicated four times. Total annual runoff was dominated by snowmelt. Generally runoff volumes, sediment yields, sediment ratios and runoff coefficients were all low. Bare ground increased with increasing grazing intensity and ...
Increasing yield for silage and grazing in cool, short-season areas may be possible by planting c... more Increasing yield for silage and grazing in cool, short-season areas may be possible by planting corn (Zea mays L.) at high population densities and at narrow row spacing. The objective was to determine how population density (75 000, 100 000, and 125 000 plants ha-1) and row spacing (standard: 76 cm and narrow: 38 cm) affected whole-plant yield, yield-related parameters, and nutritive value of two corn hybrids grown at Brooks and Lacombe, Alberta during 2 yr. The hybrids (Pioneer 39F45 and 39N03) were rated at 2000 Ontario corn heat units (CHU). Trial, hybrid, population density and row spacing interacted to influence whole-plant yield. Population density had a greater impact on whole-plant yield than row spacing and hybrid choice. Generally, yield leveled off at 100 000 plants ha-1 when the interaction of all effects was considered. Leaf area index (LAI) and whole-plant yield at this density were 2.68 and 12.0 Mg ha-1, respectively. Narrow compared with standard row spacing had pos...
The aim of this study was to identify SNP markers that associate with variation in beef heifer re... more The aim of this study was to identify SNP markers that associate with variation in beef heifer reproduction and performance of their calves. A genome-wide association study was performed by means of the generalized quasi-likelihood score (GQLS) method using heifer genotypes from the BovineSNP50 BeadChip and estimated breeding values for pre-breeding body weight (PBW), pregnancy rate (PR), calving difficulty (CD), age at first calving (AFC), calf birth weight (BWT), calf weaning weight (WWT), and calf pre-weaning average daily gain (ADG). Data consisted of 785 replacement heifers from three Canadian research herds, namely Brandon Research Centre, Brandon, Manitoba, University of Alberta Roy Berg Kinsella Ranch, Kinsella, Alberta, and Lacombe Research Centre, Lacombe, Alberta. After applying a false discovery rate correction at a 5% significance level, a total of 4, 3, 3, 9, 6, 2, and 1 SNPs were significantly associated with PBW, PR, CD, AFC, BWT, WWT, and ADG, respectively. These SN...
A series of studies was conducted to determine the efficacy and possible modes of action of a wat... more A series of studies was conducted to determine the efficacy and possible modes of action of a water-soluble mixture of alcohol ethoxylate and pluronic detergents (AEPD; Blocare 4511, ANCARE, Auckland, NZ) in preventing pasture bloat in ruminants grazing or fed freshly harvested alfalfa. Ten cannulated Suffolk wethers were offered freshly harvested alfalfa; five were given a daily intraruminal dose of 40 ml of 50% AEPD (vol/vol) 1 h before feeding, and five (controls) were dosed with water. Viscosity of ruminal fluid was reduced (P < 0.001) in AEPD-treated wethers, relative to the controls, for the first 2 h after feeding but not at 4 h after feeding and beyond. Treatment with AEPD did not affect dry matter (DM) intake, digestibility of DM, acid detergent fiber, or neutral detergent fiber, or N digestion and retention, implying that AEPD likely would not affect milk production. In a crossover grazing study, five of the wethers were given AEPD in drinking water (0.1%, vol/vol); tre...
The current study compared beef production, quality and fatty acid (FA) profiles of yearling stee... more The current study compared beef production, quality and fatty acid (FA) profiles of yearling steers fed a control diet containing 70 : 30 red clover silage (RCS) : barley-based concentrate, a diet containing 11% sunflower seed (SS) substituted for barley, and diets containing SS with15% or 30% wheat dried distillers’ grain with solubles (DDGS). Additions of DDGS were balanced by reductions in RCS and SS to maintain crude fat levels in diets. A total of two pens of eight animals were fed per diet for an average period of 208 days. Relative to the control diet, feeding the SS diet increased (P<0.05) average daily gain, final live weight and proportions of total n-6 FA, non-conjugated 18:2 biohydrogenation products (i.e. atypical dienes) with the first double bond at carbon 8 or 9 from the carboxyl end, conjugated linoleic acid isomers with the first double bond from carbon 7 to 10 from the carboxyl end,t-18:1 isomers, and reduced (P<0.05) the proportions of total n-3 FA, conjuga...
The American journal of clinical nutrition, Jun 1, 2004
Canadian beef consumption is approximately 31 kg per annum, or a third of all meats consumed. Bee... more Canadian beef consumption is approximately 31 kg per annum, or a third of all meats consumed. Beef is a nutrient-rich food, providing good quality protein, vitamins B-6 and B-12, niacin, iron, and zinc. However, animal fats have gained the reputation of being less healthy. The identification of the anticarcinogenic effects of beef extracts due to the presence of conjugated linoleic acid (CLA) has heightened interest in increasing the amount of CLA deposited in beef. Beef cattle produce CLA and deposit these compounds in the meat; thus, beef consumers can receive bioformed CLA. Beef contains both of the bioactive CLA isomers, namely, cis-9, trans-11 and trans-10, cis-12. The relative content of these CLA isomers in beef depends on the feeds consumed by the animals during production. Feeding cattle linoleic acid-rich oils for extended periods of time increases the CLA content of beef. Depending on the type and relative maturity of the pasture, beef from pasture-fed cattle may have a h...
To elucidate the effects of dietary vitamin E with or without flaxseed on beef fatty acid composi... more To elucidate the effects of dietary vitamin E with or without flaxseed on beef fatty acid composition, 80 feedlot steers were fed 4 diets: Control-E (451 IU dl-α-tocopheryl acetate/head/day), Control+E (1051 IU dl-α-tocopheryl acetate/head/day), Flax-E (10% ground) and Flax+E. Vitamin E had no effect on animal growth or carcass weight (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;0.05), while flaxseed-fed steers had greater average daily gain (p=0.007), final live weight (p=0.005) and heavier carcasses (p=0.012). Feeding flaxseed increased the total n-3 fatty acid content of beef and this response was further accentuated by the inclusion of high levels of vitamin E in the diet. Feeding flax increased levels of some 18:3n-3 partial hydrogenation products including c15- and t13/14-18:1 and several 18:2 isomers (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001) but decreased t10-18:1 (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001). Vitamin E enhanced intramuscular levels of 18:3n-3 and its biohydrogenation products leading to greater accumulations of total n-3 fatty acids in lean ground beef. The consequences of increasing the concentrations of partially hydrogenated products on human health have yet to be investigated.
Several models for simulating the growth and nutritive value of forage crops have been developed ... more Several models for simulating the growth and nutritive value of forage crops have been developed in past decades but most of them are specific to one crop species and focus only on agronomic outputs. In this study, we calibrated and evaluated the performance of the STICS crop model for the simulation of the growth and nutritive value (cell wall concentration and digestibility, in vitro true dry matter [DM] digestibility, and N concentration) of timothy (Phleum pratense L.) under Canadian growing conditions. Equations used for calculating nutritive value attributes were derived from the CATIMO model (CAnadian TImothy MOdel). The calibration included two datasets, one for eastern Canada (cultivar Champ) and one for western Canada (cultivar Climax). Very good agreement between simulations and measurements was obtained for the calibration dataset (RMSE% ≤10% for all variables). Twenty-two datasets including leaf area index (LAI), forage DM yield, N concentration, cell wall concentration and digestibility, and in vitro true DM digestibility were then used to evaluate model performance. The model simulated LAI, forage DM yield, nitrogen concentration and nutritive value of the primary growth fairly well for all sites (RMSE% <30%), but was less successful for the regrowth (i.e. average RMSE of forage DM: 66.5 and 85.9 g m −2 for primary growth and regrowth, respectively). The next step in this research will be to perform, multiannual simulations to evaluate crop reserve simulations and improve regrowth simulation.
The development of short-season hybrids has made corn (Zea mays L.) silage (CS) production possib... more The development of short-season hybrids has made corn (Zea mays L.) silage (CS) production possible in cooler areas. This work aimed at determining biomass yield and nutritive quality of short-season corn CS hybrids. Six corn hybrids were grown in three years at four locations within the Canadian prairies with four field replications. Hybrids were harvested before occurrence of frost at a target dry matter (DM) content of 300 to 400 g kg−1. Corn heat units (CHU) from seeding to harvesting (CHUseed-harv) and water supply were recorded. Samples were analysed for nutrient content; i.e., DM, neutral detergent fiber (NDF), crude protein (CP), starch, and in vitro DM and NDF digestibilities (48 h incubation). Then, CHUseed-harv, water supply, whole plant DM, CHU rating of the hybrid, and cob percentage were assessed as predictors of nutrient content. Location, hybrid, and year affected nutrient composition and yield. Overall, CP and NDF were positively correlated (r = 0.48, p < 0.01), ...
Doce, R. R., Baron, V. S., and Dick, A. C. 2015. Estimating swath-grazed carrying capacity from p... more Doce, R. R., Baron, V. S., and Dick, A. C. 2015. Estimating swath-grazed carrying capacity from plot-scale data. Can. J. Plant Sci. 95: 647–651. A spreadsheet calculator was developed to estimate farm-scale carrying capacities for swath grazing beef cows with forage yield and quality data from small areas within fields or paddocks. It could be used to compare agronomic treatments for swath grazing potential from plot data when combined with existing beef nutrition equations. Examples using either in vitro true digestibility at 30-h digestion or acid detergent fiber (ADF) in equations to estimate digestible energy were compared with actual field-scale carrying capacities to evaluate the ability of the methods to meet requirements of scale, precision and accuracy. Both methods were capable of estimating carrying capacity at a realistic whole-farm scale, but the ADF-based method was superior with respect to accuracy and precision characteristics.
Manafiazar, G., Basarab, J. A., Baron, V. S., McKeown, L., Doce, R. R., Swift, M., Undi, M., Witt... more Manafiazar, G., Basarab, J. A., Baron, V. S., McKeown, L., Doce, R. R., Swift, M., Undi, M., Wittenberg, K. and Ominski, K. 2015. Effect of post-weaning residual feed intake classification on grazed grass intake and performance in pregnant beef heifers. Can. J. Anim. Sci. 95: 369–381. There is limited knowledge of how cattle tested for feed efficiency under drylot conditions perform when they graze on summer pasture. Residual feed intake adjusted for end of test backfat thickness (RFIfat) was determined on 171 beef crossbred heifers under drylot conditions over 2 yr using an automated system. Upon completion of the test, the 10 lowest and 10 highest RFIfat (–0.54±0.17 vs. 0.58±0.15 kg DM d−1) heifers in 2012, and the 14 lowest and 14 highest RFIfat (−0.47±0.16 vs. 0.53±0.19 kg DM d−1) heifers in 2013 were selected and placed on meadow bromegrass pasture to investigate the effect of RFIfat ranking on their grass intake and performance on the pasture. The pasture adaptation period (8 ...
Spring-planted mixtures of spring and winter cereals in a silage/fall pasture system have been sh... more Spring-planted mixtures of spring and winter cereals in a silage/fall pasture system have been shown to extend the grazing season in the Parkland of the Canadian prairies. Experiments were conducted at Lacombe, Alberta to determine the effects of planting date on yield and yield components of spring-seeded spring oat (Avena sativa L.), winter wheat (Triticum aestivum L.), winter triticale (X Triticosecale Wittmack) and winter rye (Secale cereale L.). The cereals were grown as monocrops or as binary mixtures of the oat and winter cereals. Treatments were planted in early May and mid-June and harvested twice for forage. The initial harvest for early and late planting dates occurred when oat reached the early-milk and heading stages, respectively. Regrowth was harvested in mid- to late September. The planting date x treatment interaction did not affect (P ≤ 0.05) annual yield (initial + regrowth) even though oat was harvested at different developmental stages. Averaged over treatments,...
The response in composition, in vitro dry matter digestibility (IVDDM), and enzymatic saccharific... more The response in composition, in vitro dry matter digestibility (IVDDM), and enzymatic saccharification, of alfalfa and various grasses to selective solvent delignification (SSD), as well as the nutritive value of the residual biomass (co-product), was determined. The SSD pretreatment reduced lignin concentrations in grasses but not in alfalfa. Associated effects were increases in concentrations of neutral detergent fiber (NDF) due
larly well adapted for grazing, but are sometimes used for hay in the western parkland of Alberta... more larly well adapted for grazing, but are sometimes used for hay in the western parkland of Alberta (Baron and Grasses adapted to both hay and pasture are lacking in the prairie Knowles, 1984; Knowles and Baron, 1990; Knowles et parkland. 'Regar' meadow bromegrass (Bromus riparius Rhem.), 'Manchar' smooth bromegrass (B. inermis Leyss.), S9044 (a smooth-al., 1993). Meadow bromegrass-smooth bromegrass meadow bromegrass cross), common meadow foxtail (Alopercurus crosses have been made to develop dual-purpose grazpratensis L.), and 'Kay' orchardgrass (Dactylis glomerata L.) were ing/hay type cultivars for the Canadian Prairies evaluated for traits useful in dual purpose grass species at early (late (Knowles and Armstrong, 1984). During the late 1980s May), late (late June), and regrowth (early September) harvests. and through the 1990s, orchardgrass has been grown Herbage, leaf, and stem nutritive value; mass; and leaf/stem ratio were extensively in the more moist areas of Alberta. These determined. Differences among species were related more to herbage genotypes have been compared for seasonal herbage mass and morphology than to leaf and stem quality. Early harvest mass when cut frequently and infrequently (Knowles orchardgrass herbage mass was low at 55% of meadow foxtail (2.9 and Baron, 1990; Knowles et al., 1993), but comprehen-Mg ha Ϫ1). However, stem content of meadow foxtail represented 60% of early herbage mass, limiting its potential. Regrowth mass of sive evaluation of their potential is required to provide meadow bromegrass, S9044, and orchardgrass exceeded 2.5 Mg ha Ϫ1 , improved seasonal utilization. whereas smooth bromegrass and meadow foxtail were as low as 2.1 When characterizing forage potential of grass species Mg ha Ϫ1. Regrowth leaf mass of the former species exceeded 1.9 Mg used for hay and grazing, it is important to evaluate ha Ϫ1. Late herbage mass of smooth bromegrass was always greater traits such as mass, sward structure, plant morphology, than the other species. Leaf acid detergent fiber (ADF) of S9044 and and nutritive value of leaf and stem materials. Defining smooth bromegrass was lower (range 189-242 g kg Ϫ1) than meadow forage quality potential for hay (often initial growth) is bromegrass (range 217-284 g kg Ϫ1). By contrast, late and regrowth relatively simple compared with pasture, since hay can harvest stem ADF of meadow bromegrass was lower (range 237-360 be fed ad libitum in stalls to estimate intake, and digestg kg Ϫ1) than S9044 (range 257-366 g kg Ϫ1). Variation among Bromus types for late and regrowth yield, and leaf fiber may influence manage-ible dry matter intake is directly related to forage qualment strategies. ity. Some selection of leaf material occurs, but most of the entire plant is consumed. Under grazing, the relationships between forage mass, sward structure, and nutritive value are important M atching forage nutritive value and availability with livestock production goals is a challenge, aspects of forage potential. Forage mass and sward especially in areas with short growing seasons. In central structure (leaf/stem ratio, leaf mass, etc.) may influence Alberta, Canada, grass species with regrowth characteranimal intake (Coleman, 1992) and must be taken into istics necessary in intensive pasture management were consideration together with conventional nutritive panot available until the last decade. Species and genorameters. As pasture mass increases animal intake levels types within species with adequate regrowth characterisoff, and forage nutritive value becomes more important tics have been identified and developed during the last than sward structure. The pasture mass at maximum 10 to 15 yr. Examples are meadow foxtail, meadow intake is often obscure, varying from 1.2 Mg ha Ϫ1 of bromegrass, and crosses between meadow and smooth green leaf material in cool-season grasses to 3.5 Mg ha Ϫ1 bromegrass. in warm-season grasses (Coleman, 1992; Forbes and Meadow foxtail and meadow bromegrass are particu-Coleman, 1993; Penning et al., 1994). Also, ruminant animals tend to select leaves instead of stems (Poppi et V.S. Baron and A.C. Dick, Agriculture and Agri-Food Canada, 6000 al., 1980) and select live material instead of dead mate
Regrowth in pastures is critical to economic production in short‐season areas. This study compare... more Regrowth in pastures is critical to economic production in short‐season areas. This study compared regrowth characteristics among three Bromus genotypes and meadow foxtail (Alopecurus pratensis L.) during late summer and fall. Growth analyses were conducted and yield components were determined in ‘Carlton’ smooth bromegrass (B. inermis Leyss.), ‘Regar’ meadow bromegrass (B. riparius Rhem.), an experimental strain (S9044) derived from F2 plants of a smooth ✕ meadow bromegrass cross, and common meadow foxtail. Seven weeks of plant regrowth after severe defoliation were characterized during 1985 and 1986 at Lacombe, AB, Canada (52° 28' N lat). The variation among the three grass species and the interspecific hybrid that was most critical to regrowth yield occurred during the first 21 to 28 d after defoliation. Smooth bromegrass consistently yielded less dry matter (DM) and had lower crop growth rates (CGR) than the other genotypes. Smooth bromegrass seemed limited most by a slowly ...
Currently, there is interest in Western Canada in extending the grazing season using perennial an... more Currently, there is interest in Western Canada in extending the grazing season using perennial and annual forages. Of greatest concern is the environmental sustainability of these grazing systems, with emphasis on their ability to withstand erosion. A study to examine the runoff and sediment yields of annual and perennial forages in central Alberta was initiated in 1994. Runoff and sediment yield were quantified under snowmelt and rainfall events for two seasons. Rainfall simulation was used to further examine runoff under growing season conditions. Four forage treatments (two annuals: triticale and a barley/triticale mixture and two perennials: smooth bromegrass and meadow bromegrass) and three grazing intensities (light, medium and heavy) were studied, each replicated four times. Total annual runoff was dominated by snowmelt. Generally runoff volumes, sediment yields, sediment ratios and runoff coefficients were all low. Bare ground increased with increasing grazing intensity and ...
Increasing yield for silage and grazing in cool, short-season areas may be possible by planting c... more Increasing yield for silage and grazing in cool, short-season areas may be possible by planting corn (Zea mays L.) at high population densities and at narrow row spacing. The objective was to determine how population density (75 000, 100 000, and 125 000 plants ha-1) and row spacing (standard: 76 cm and narrow: 38 cm) affected whole-plant yield, yield-related parameters, and nutritive value of two corn hybrids grown at Brooks and Lacombe, Alberta during 2 yr. The hybrids (Pioneer 39F45 and 39N03) were rated at 2000 Ontario corn heat units (CHU). Trial, hybrid, population density and row spacing interacted to influence whole-plant yield. Population density had a greater impact on whole-plant yield than row spacing and hybrid choice. Generally, yield leveled off at 100 000 plants ha-1 when the interaction of all effects was considered. Leaf area index (LAI) and whole-plant yield at this density were 2.68 and 12.0 Mg ha-1, respectively. Narrow compared with standard row spacing had pos...
The aim of this study was to identify SNP markers that associate with variation in beef heifer re... more The aim of this study was to identify SNP markers that associate with variation in beef heifer reproduction and performance of their calves. A genome-wide association study was performed by means of the generalized quasi-likelihood score (GQLS) method using heifer genotypes from the BovineSNP50 BeadChip and estimated breeding values for pre-breeding body weight (PBW), pregnancy rate (PR), calving difficulty (CD), age at first calving (AFC), calf birth weight (BWT), calf weaning weight (WWT), and calf pre-weaning average daily gain (ADG). Data consisted of 785 replacement heifers from three Canadian research herds, namely Brandon Research Centre, Brandon, Manitoba, University of Alberta Roy Berg Kinsella Ranch, Kinsella, Alberta, and Lacombe Research Centre, Lacombe, Alberta. After applying a false discovery rate correction at a 5% significance level, a total of 4, 3, 3, 9, 6, 2, and 1 SNPs were significantly associated with PBW, PR, CD, AFC, BWT, WWT, and ADG, respectively. These SN...
A series of studies was conducted to determine the efficacy and possible modes of action of a wat... more A series of studies was conducted to determine the efficacy and possible modes of action of a water-soluble mixture of alcohol ethoxylate and pluronic detergents (AEPD; Blocare 4511, ANCARE, Auckland, NZ) in preventing pasture bloat in ruminants grazing or fed freshly harvested alfalfa. Ten cannulated Suffolk wethers were offered freshly harvested alfalfa; five were given a daily intraruminal dose of 40 ml of 50% AEPD (vol/vol) 1 h before feeding, and five (controls) were dosed with water. Viscosity of ruminal fluid was reduced (P < 0.001) in AEPD-treated wethers, relative to the controls, for the first 2 h after feeding but not at 4 h after feeding and beyond. Treatment with AEPD did not affect dry matter (DM) intake, digestibility of DM, acid detergent fiber, or neutral detergent fiber, or N digestion and retention, implying that AEPD likely would not affect milk production. In a crossover grazing study, five of the wethers were given AEPD in drinking water (0.1%, vol/vol); tre...
The current study compared beef production, quality and fatty acid (FA) profiles of yearling stee... more The current study compared beef production, quality and fatty acid (FA) profiles of yearling steers fed a control diet containing 70 : 30 red clover silage (RCS) : barley-based concentrate, a diet containing 11% sunflower seed (SS) substituted for barley, and diets containing SS with15% or 30% wheat dried distillers’ grain with solubles (DDGS). Additions of DDGS were balanced by reductions in RCS and SS to maintain crude fat levels in diets. A total of two pens of eight animals were fed per diet for an average period of 208 days. Relative to the control diet, feeding the SS diet increased (P<0.05) average daily gain, final live weight and proportions of total n-6 FA, non-conjugated 18:2 biohydrogenation products (i.e. atypical dienes) with the first double bond at carbon 8 or 9 from the carboxyl end, conjugated linoleic acid isomers with the first double bond from carbon 7 to 10 from the carboxyl end,t-18:1 isomers, and reduced (P<0.05) the proportions of total n-3 FA, conjuga...
The American journal of clinical nutrition, Jun 1, 2004
Canadian beef consumption is approximately 31 kg per annum, or a third of all meats consumed. Bee... more Canadian beef consumption is approximately 31 kg per annum, or a third of all meats consumed. Beef is a nutrient-rich food, providing good quality protein, vitamins B-6 and B-12, niacin, iron, and zinc. However, animal fats have gained the reputation of being less healthy. The identification of the anticarcinogenic effects of beef extracts due to the presence of conjugated linoleic acid (CLA) has heightened interest in increasing the amount of CLA deposited in beef. Beef cattle produce CLA and deposit these compounds in the meat; thus, beef consumers can receive bioformed CLA. Beef contains both of the bioactive CLA isomers, namely, cis-9, trans-11 and trans-10, cis-12. The relative content of these CLA isomers in beef depends on the feeds consumed by the animals during production. Feeding cattle linoleic acid-rich oils for extended periods of time increases the CLA content of beef. Depending on the type and relative maturity of the pasture, beef from pasture-fed cattle may have a h...
To elucidate the effects of dietary vitamin E with or without flaxseed on beef fatty acid composi... more To elucidate the effects of dietary vitamin E with or without flaxseed on beef fatty acid composition, 80 feedlot steers were fed 4 diets: Control-E (451 IU dl-α-tocopheryl acetate/head/day), Control+E (1051 IU dl-α-tocopheryl acetate/head/day), Flax-E (10% ground) and Flax+E. Vitamin E had no effect on animal growth or carcass weight (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;0.05), while flaxseed-fed steers had greater average daily gain (p=0.007), final live weight (p=0.005) and heavier carcasses (p=0.012). Feeding flaxseed increased the total n-3 fatty acid content of beef and this response was further accentuated by the inclusion of high levels of vitamin E in the diet. Feeding flax increased levels of some 18:3n-3 partial hydrogenation products including c15- and t13/14-18:1 and several 18:2 isomers (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001) but decreased t10-18:1 (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001). Vitamin E enhanced intramuscular levels of 18:3n-3 and its biohydrogenation products leading to greater accumulations of total n-3 fatty acids in lean ground beef. The consequences of increasing the concentrations of partially hydrogenated products on human health have yet to be investigated.
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