bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of once daily 5-h or 10-h cold-exposures on body temperature and resting heat production of beef cattle
Authors: Kennedy A. D. , Bergen R. D. , Christopherson R. J. , Glover N. D. , Small J. A.
Published: April 2011

Twelve yearling crossbred beef heifers weighing 454 ± 31 kg were randomly assigned to either 0 h (control), 5 h (5CE; 0800 to 1300) or 10 h (10CE; 0800 to 1800) of cold exposure (-20°C) daily to determine the effect of daily cold exposures of different durations on body core temperature and resting heat production of beef cattle. Treatments were imposed for a 21-d period (seven intervals of 3 d duration) using two replications with two heifers per treatment × replication combination. Heifers were group housed outdoors in a pen with overhead shade at one end and were moved daily at 0800 to a group pen in either a control room or an environmental chamber set at -20°C. After the 21-d period was completed, resting heat production was measured in a thermal neutral environment for 5 h. Vaginal temperature (Tvag) was continuously monitored using radiotransmitters. Treatment did not affect daily maximum, mean or minimum Tvag, the amount of time spent at Tvag exceeding daily mean Tvag, or the variability of Tvag (P ≥ 0.29). However, when examined within specific phases of the day, treatment effects on Tvag were found. Tvag was elevated 0.24°C (5CE) and 0.35°C (10CE) during the daily first 5 h of cold-exposure (10CE = 5CE > control; P = 0.02) throughout the entire 21-d trial. During other times of the day there was no effect of treatment on Tvag but treatment × interval was significant (P ≤ 0.02) during the 6–10 h from initiation of cold-exposure when the 10CE group remained in the cold but the 5CE group had been returned to the outdoor pen. The Tvag of the 10CE and 5CE heifers was elevated at this time of day compared to control heifers, but only during the first 4 to 6 d (5CE) or 7 to 9 d (10CE) of the trial. These results indicate that thermoregulatory mechanisms that control core body temperature undergo habituation and the timecourse of habituation depends on the duration of daily cold- exposure. Resting heat production was unaffected by the two durations of cold-exposure examined (P = 0.55), suggesting that metabolic acclimation does not occur in response to intermittent cold-exposure of beef cattle. Key words: Beef heifers, vaginal temperature, resting heat production, environment, cold duration
Microarray analysis of gene expression following preparation of sterile intestinal “loops” in calves
Authors: Aich Palok , Wilson Heather L , Rawlyk Neil A. , Jalal Shakiba , Kaushik Radhey S , Begg Ashley A , Potter Andrew A , Babiuk Lorne A , Abrahamsen Mitchell S , Griebel Philip J
Published: April 2011

The surgical preparation of multiple, sterile intestinal “loops” has provided an effective model for the analysis of vaccine-induced mucosal immune responses in ruminants. The objective of the present investigation was to evaluate intestinal “loops” as a model for genomic analyses of mucosal immune responses. Immunohistochemistry revealed no significant changes in mucosal epithelial cell architecture but microarray analyses were completed to determine if surgery and elimination of microflora significantly altered gene expression in the small intestine of one month-old calves. RNA was isolated from intestinal “loops” (Sample) and adjacent, intact intestine (Control) of each animal at 48 h (n = 3) and 12 d (n = 3) postsurgery. Total RNA from control and sample tissues was hybridized on Pyxis Genomics bovine cDNA microarrays (7884 ESTs) to identify differentially expressed genes. We observed only 2.3% (180/7884) of ESTs were significantly and differentially changed in expression at 48 h post-surgery and approximately 80% (143/180) of these genes were up-regulated. A subset of these differentially expressed genes was validated by quantitative Real Time PCR and these analyses demonstrated that many genes were returning to baseline expression levels at 12 d post-surgery. Notable among differentially expressed genes were gene clusters involved in apoptosis, cell cycle, and cell differentiation. Surgery and elimination of microflora in 1-mo-old calves significantly altered the expression of a relatively minor number of genes but these genes were implicated in important aspects of normal mucosal function. Therefore, intestinal “loops” that control for the effects of surgical manipulation and commensal microflora must be included when conducting mucosal gene expression analyses within this animal model. Key words: Bovine, Cy-dye fluorescence, immunohistochemistry, intestine, microarray, microflora, resonance light scattering, qRT-PCR
Effects of feeding wheat straw and middlings ensiled with whey on digestibility and growth of cattle
Authors: ZoBell D. R. , Okine E. K. , Olson K. C. , Wiedmeier R. D. , Goonewardene L. A. , Stonecipher C.
Published: April 2011

Two studies were conducted with the objective of evaluating the effects of feeding different levels of whey ensiled with wheat straw and wheat middlings (whey silage) compared to control diets on production parameters in growing cattle. Whey silage was included in diets at 55 and 65.5% on a dry matter basis with net energy for maintenance and crude protein calculated to be similar to control diets containing a combination of alfalfa hay, corn silage and wheat middlings at 1.74 Mcal kg-1 and 13.4%, respectively. Dry matter intake averaged 8.41 versus 8.91 kg d-1 (P < 0.05) and 8.68 versus 7.09 kg d-1 (P < 0.05) when whey silage was included at either 55 or 65.5% of the diets compared to the control diets. Average daily gains of cattle fed whey silage incorporated at 55% was 1.00 versus 1.14 kg d-1 (P < 0.05), and reflected the difference in dry matter intake; no differences (P > 0.05) in feed efficiency (8.73:1 versus 8.71:1) were observed. However, the higher dry matter intake (DMI) of cattle fed diets with whey silage incorporated at 65.5% did not (P > 0.05) translate into higher average daily gain (1.23 versus 1.18 kg d-1), resulting in a higher (P < 0.05) feed to gain (7.00:1 versus 6.01:1) for the whey-based silage diets. Incorporation of whey silage in diets at 55% increased (P > 0.05) the dry matter digestibility by 12%, whereas incorporation at 65.5% decreased (P < 0.05) dry matter digestibility by 12% compared to control diets, with no differences (P > 0.05) in percent neutral detergent fiber digestibility (NDFD) at either level. We conclude that whey silage can be included at between 55 and 65.5% of the total dry matter in diets with no adverse effects on production compared to cattle fed diets containing a combination of alfalfa hay, corn silage and wheat middlings. Key words: Agricultural by products, crop residues, digestibility, growing cattle, production, whey silage
Effect of stocking rate on pig performance in a wean-to-finish production system
Authors: DeDecker J. M. , Ellis M. , Wolter B. F. , Corrigan B. P. , Curtis S. E. , Hollis G. R.
Published: April 2011

Crossbred pigs (n = 1,296) were used in a randomized complete block design to evaluate three stocking rate treatments (22, 27, or 32 pigs pen-1) on growth performance from weaning [5.0 ± 0.01 kg body weight (BW); 15 ± 1 d of age] to 24 wk post-weaning. Floor and feeder spaces per pig were 0.78 m2 and 4.2 cm, 0.64 m2 and 3.4 cm, and 0.54 m2 and 2.9 cm for group sizes of 22, 27, and 32, respectively. During the first 8 wk postweaning there was a tendency for average daily gain (ADG) (511, 505, and 497 g d-1, respectively; P = 0.07) and BW (35.1, 34.7, and 34.3 kg, respectively; P = 0.08) to decrease linearly as stocking rate increased. Moreover, from week 8 to 18, week 18 to 24, and for the overall period (weaning to week 24) both ADG (688, 660, and 635 g d-1 for the overall period, respectively) and BW (121.8, 117.1 and 113.1 kg at week 24, respectively) decreased linearly (P < 0.001) with increasing stocking rate. There were no treatment differences in the coefficient of variation in pig BW within a pen at any stage of the study. Morbidity and mortality rates increased linearly (8.5, 10.2, and 12.7%; P < 0.05) with increasing stocking rate. In conclusion, decreasing group size, thereby increasing floor and feeder space pig-1, reduced morbidity and mortality and increased growth rate after 8 wk post-weaning resulting in heavier pigs at 24 wk post-weaning for the smaller groups. Key words: Pigs, stocking rate, weaning, finishing
Dietary amino acids affect intestinal Clostridium perfringens populations in broiler chickens
Authors: Wilkie Darryl C , Van Kessel Andrew G , White Lisa J , Laarveld Bernard , Drew Murray D
Published: April 2011

An experiment was performed to examine the effect of protein source and dietary amino acid profile on intestinal levels of C. perfringens in broiler chickens. Broiler chickens (age = 14 d; n = 192) were fed diets containing 400 g kg-1 crude protein with fish meal, meat/bone meal, feather meal, corn gluten meal, soy protein concentrate, pea protein concentrate, or potato protein concentrate as the primary protein source along with a control diet containing 230 g kg-1 crude protein. The birds were orally inoculated daily, with 1 mL (~1.0 × 108 CFU mL-1) of an overnight culture of C. perfringens between 14 and 21 d of age, killed at 28 d of age and C. perfringens numbers in ileum and cecum were enumerated. Birds fed fish meal, meat/bone meal, feather meal and potato protein concentrate had significantly higher intestinal C. perfringens counts than the birds fed corn gluten meal, soy or pea protein concentrates or the control diet (P < 0.05). The glycine content of the diets and ileal contents was significantly, positively correlated with C. perfringens numbers in ileum and cecum. Dietary glycine may be an important factor in the intestinal overgrowth of C. perfringens in broiler chickens. Key words: Clostridium perfringens, broiler chicken, amino acid, glycine, necrotic enteritis
Effect of supplemental copper proteinate on reproductive performance of first- and second-parity sows
Authors: Yen J. T. , Ford J. J. , Klindt J.
Published: April 2011

The effects of copper supplementation in the form of copper proteinate (CuP) on sow reproductive performance were determined. In Trial 1, 140 parity-1 and parity-2 sows received basal (B) or CuP treatment from day 108 of gestation through day 14 after weaning. Each CuP-fed sow received daily 40 g dried molasses that contained 0.32% CuP, which supplied 14 mg d-1 Cu as CuP; B-fed sows received no dried molasses. After weaning, sows were housed in large breeding pens (3.6 m × 6.6 m). Weaning-to-estrus interval was shorter (P < 0.05) and percentage bred by day 7 postweaning was greater (P < 0.05) for CuP-fed than for B-fed sows. Trials 2 and 3 used 110 and 56 parity-1 sows, respectively. Treatments (40 g of dried molasses, B, or 40 g of CuP-supplemented dried molasses, which provided 14 mg d-1 Cu) were administered from day of farrowing to day 7 postweaning. Weaned sows were housed in small breeding pens (2.4 m × 3.6 m) in Trial 2, and in large pens (the same as used in Trial 1) in Trial 3. No treatment differences (P ≥ 0.48) were detected in Trial 2. In Trial 3, CuP supplementation tended to increase (P = 0.09) percentage of sows bred by day 7 postweaning. In conclusion, supplemental Cu as CuP fed to sows housed in large breeding pens can increase the percentage bred by day 7 postweaning. Key words: Copper proteinate, reproductive performance, sows
Detection of feed-ingested plant DNA fragments in a raw meat product for human consumption
Authors: Reuter T. , Aulrich K. , Schnäckel W. , McAllister T. A.
Published: April 2011

To investigate the potential for foreign DNA in swine tissue to persist in foods for human consumption, a raw meat product (gammon) was prepared from gluteus maximus samples in which plant DNA was present. Degradation of DNA during salt-curing was evident, but a 140-bp fragment of maize chloroplast DNA remained detectable in 6 of 12 samples analyzed. Key words: Food, gammon, genetically modified organism, maize, PCR, pig
Effect of dietary Ca manipulation, anionic salts and supplemental vitamin D3 on calcium homeostasis of finishing steers
Authors: Aranda-Osorio G. , Van Kessel A. , Olkowski A. A. , McAllister T. A. , McKinnon J. J.
Published: April 2011

The objective of this study was to evaluate the effects of a low-Ca diet, followed by a high-Ca diet in combination with feeding of anionic salts and/or vitamin D3 on Ca and acid-base homeostasis of finishing steers. Twenty Hereford steers (448 _ 26 kg) were individually penned and fed at 0800 and 1600 with a ration consisting of 90% barley grain-based concentrate and 10% barley silage (DM basis). The experimental protocol included a 19-d adaptation period, a 14-d period of low Ca feeding, a 10-d supplemental period and a 5-d withdrawal period. During the supplemental period, anionic salts (MgSO4 and NH4Cl) were incorporated into the diet at -1500 and -3000 mEq steer-1 d-1 for 3 and 7 d, respectively. The cattle were also supplemented with one of four vitamin D3 treatments: 0, 0.6, 1.2 and 2.4 million IU (MIU) of vitamin D3 steer-1 d-1. Blood samples were obtained for measurement of total and ionized Ca, parathyroid hormone (PTH) and calcitonin, vitamin D3, 25(OH)D3 and 1,25(OH)2D3. Feed intake was depressed (P < 0.05) by anionic salt feeding but not vitamin D3 treatment. Cattle supplemented with vitamin D3 had higher total (P < 0.05) and ionized (P < 0.05) serum Ca levels than the control cattle that were only supplemented with anionic salts. Higher (P < 0.04) ionized Ca levels were seen in cattle fed 2.4 versus those fed 0.6 MIU vitamin D3. Maximum total serum Ca values were 10.11, 10.97, 11.43 and 12.24 mg dL-1 for the 0, 0.6, 1.2 and 2.4 MIU vitamin D3 treatments, respectively. Respective maximum values for ionized Ca were 5.43, 5.90, 5.98 and 6.25 mg dL-1. These values represent increases, relative to the adaptation period of 3, 12, 16 and 25% for total and 9, 18, 20 and 31% for ionized Ca for the 0, 0.6, 1.2 and 2.4 MIU D3 treatments, respectively. Circulating concentrations of vitamin D3, 25(OH)D3, and 1,25(OH)2D3 were increased (P < 0.05) by vitamin D3 feeding, however, PTH was decreased (P < 0.05), while calcitonin was not affected (P > 0.05). Anionic salt feeding induced (P < 0.05) a mild systemic acidosis. The results indicate that anionic salt feeding enhanced the response of serum Ca to vitamin D3 supplementation. Higher serum Ca levels prior to slaughter may increase intra-muscular Ca levels and enhance postmortem activity of Ca-dependant proteases responsible for myofibril degradation. The results point to a dietary strategy that with further research may prove useful in enhancing beef tenderness. Of particular interest is that serum Ca levels were elevated when vitamin D3 was supplemented at levels 25 to 50% or less than levels used in previous research. Key words: Calcium homeostasis, vitamin D3, anionic salts, beef tenderness
Rapid, sensitive and versatile determination of selenium in different biological samples
Authors: Giguère Alain , Fortier Marie-Ève , Matte J. Jacques
Published: April 2011

The reliable assessment of selenium in biological samples is generally technically difficult to achieve and requires a large amount of material. The described fluorometric method was validated using certified standard material of Durum Wheat Flour, Bovine Muscle Powder, Whole Egg Powder and serum and was tested on pig whole blood and fresh egg. The technique was found to be fast, sensitive and robust for a reliable determination of Se in small amounts (< 50 mg or 100 µL) of biological samples. Key words: Selenium, analysis, biological samples
The impact of antemortem nutrition in beef cattle on carcass yield and quality grade
Authors: Schaefer A. L. , Stanley R. W. , Tong A. K. W. , Dubeski P. , Robinson B. , Aalhus J. L. , Robertson W. M.
Published: April 2011

Three thousand and thirty-six crossbred steers and heifers averaging 570 ± 7.1 kg were used in the present study to test the efficacy of providing antemortem nutrition for 12 to 24 h pre-slaughter on carcass yield, grade and meat quality. All cattle were transported for up to 6 h prior to being held overnight at one of three midwestern USA abattoir sites. While at the abattoir, the cattle were randomly assigned to one of three treatments: control (offered water only 12 to 24 h pre-slaughter, which is industry standard practice); placebo (offered 2 kg per head of a rice hull-corn-based pelleted feed for 12 to 24 h pre-slaughter plus ad libitum water); or nutritional therapy (offered 2 kg of an energy/amino acid/electrolyte product plus ad libitum water for 12 to 24 h pre-slaughter). The cattle offered antemortem nutritional therapy displayed a 20% or greater retention of quality grade score (P < 0.01) and a significant reduction in dark-firm-dry beef (P < 0.05) compared with either the placebo or control animals. In addition, animals receiving nutritional therapy treatment had a greater retention of carcass weight (≥ 2 kg, P < 0.05) compared with control cattle. Data from the present study suggest that the use of antemortem nutrition, especially for overnight-held cattle, may be effective in reducing carcass loss and quality grade reduction. Key words: Antemortem, nutrition, beef, cattle
Nutritional value of wheat and corn distiller’s dried grain with solubles: Digestibility and digestible contents of energy, amino acids and phosphorus, nutrient excretion and growth performance of grower-finisher pigs
Authors: Widyaratne G. P. , Zijlstra R. T.
Published: April 2011

Two experiments were conducted to evaluate the nutritional value of distiller’s dried grains with solubles (DDGS) samples derived from corn, wheat and a wheat/corn blend (4:1). Specifically, the digestibility and digestible contents of energy, amino acids (AA) and P, N and P excretion, and growth performance were determined in grower-finisher pigs. In exp. 1, 12 ileal cannulated barrows (64.6 ± 6.4 kg) had restricted access (2.6 × maintenance) to a wheat-control diet or one of three diets containing 40% DDGS sample of corn, wheat or wheat/corn origin that replaced wheat. For energy, apparent total tract digestibility was highest for wheat (85%; P < 0.05) and did not differ among the DDGS samples (77 to 79%; P > 0.10). Total tract digestible energy (DE) was higher for corn DDGS (4292 kcal kg-1 DM; P < 0.05) than wheat/corn DDGS, wheat DDGS and wheat samples (4038, 4019 and 3807). For lysine, apparent ileal digestibility (AID) was highest for wheat (71%; P < 0.05) and did not differ among DDGS samples (59 to 63%; P > 0.10). The AID lysine content was highest for corn DDGS (0.51% DM; P < 0.05), intermediate for wheat/corn DDGS and wheat DDGS (0.45 and 0.42), and lowest for wheat (0.37%). For P, total tract digestibility was lowest for wheat (15%; P < 0.05) and did not differ among DDGS samples (53 to 56%; P > 0.10). Total N excretion was highest for wheat/corn DDGS and wheat DDGS (55 and 58 g d-1; P < 0.05), intermediate for corn DDGS (44) and lowest for wheat (36). Total P excretion did not differ among DDGS (11 g d-1) and was lowest for wheat (8; P < 0.05). In exp. 2, 100 pigs (52.0 ± 3.3 kg) were fed a wheat-pea control diet or one of three diets containing 25% of the three DDGS samples (3.375 Mcal DE kg-1; 2.50 g SID lysine Mcal-1 DE) for 5 wk. Overall, average daily feed intake (ADFI) and daily gain (ADG) were higher for pigs fed the wheat control diet than the DDGS-containing diets (P < 0.05), but feed efficiency did not differ (P > 0.10). In summary, the digestible nutrient content of wheat DDGS is lower than corn DDGS and higher than wheat. Followin g pre-characterization of digestible nutrient profile, feeding DDGS reduced growth performance indicating that further research is required to improve the nutritional value of DDGS. Key words: Distiller's dried grains with solubles, pig, digestibility, energy, amino acid
Sequence characterization, tissue-specific expression and polymorphism of the porcine intestinal-type fatty acid binding protein gene
Authors: Jiang Y. Z. , Li X. W.
Published: April 2011

The intestinal fatty-acid-binding protein (IFABP) shows binding specificity for long-chain fatty acids and is proposed to be involved in the uptake of dietary fatty acids and their intracellular transport. In this study, the full-length cDNA of porcine I-FABP gene was obtained by the rapid amplification of cDNA ends (RACE). The nucleotide sequence and the predicted protein sequence share high sequence identity with its mammalian counterparts. Northern hybridization and semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) revealed that porcine I-FABP is expressed in all 12 tissues studied (heart, brain, kidney, skeletal muscle, testis, liver, skin, small intestine, fat, stomach, lymph and pituitary), but a transcript of approximate 620 bp is more abundant in small intestine than in other tissues. The full-length genomic DNA of the porcine I-FABP gene was amplified by PCR. The coding region of the pig IFABP gene is organized in four exons and spans an approximate 3.5-kb genomic region. Comparative sequencing of four pig breeds revealed a single nucleotide polymorphism (SNP) within exon 1 of which an A→G substitution at codon 21 changes a codon for lysine into a codon for arginine. The distribution of allele and genotype frequencies differed significantly between indigenous Chinese Zang, Dahe and Yanan breeds (higher frequencies of A and AA) and Western Large White breed (higher frequencies of G and GG, P < 0.01). The association analysis using five pig populations suggested that A21G polymorphism was associated with intramuscular fat content, indicating that the I-FABP gene A21G SNP can be a potential molecular marker for intramuscular fat content. Key words: Association analysis, cloning, gene expression, I-FABP gene, polymorphism, porcine
Effect of pasture type (alfalfa vs. grass) on methane and carbon dioxide production by yearling beef heifers
Authors: Chaves A. V. , Thompson L. C. , Iwaasa A. D. , Scott S. L. , Olson M. E. , Benchaar C. , Veira D. M. , McAllister T. A.
Published: April 2011

The objective of this study was to determine effect of pasture type on methane and carbon dioxide production by heifers grazing alfalfa or grass pastures at three sites across western Canada. All pastures were intensively managed so that heifers had ad libitum access to new forage material each day, and pastures were back-fenced to prevent the heifers accessing previously grazed areas. As measured using the sulfur hexafluoride (SF6) tracer technique, total methane production at the Brandon, MB, and Swift Current, SK, sites was unaffected by pasture type (averaging 157.4 g CH4 head-1 d-1), whereas at Lethbridge, AB, heifers grazing alfalfa produced more methane than did those on the grass pasture (162.8 vs. 113.5 g CH4 head-1 d-1; P < 0.05). Calculated with dry matter intake (DMI) estimated by alkane analysis, methane production per unit DMI was 3 9% lower from heifers consuming grass compared with alfalfa (P < 0.001). When intakes were estimated by the Cornell Net Carbohydrate and Protein System (CNCPS) model, CH4 production kg-1 DMI did not differ (P > 0.05) between pasture types. Loss of gross energy intake (GEI) to methane, as estimated by alkane analysis, was 6.9% for heifers grazing grass, and 9.6% for heifers grazing alfalfa (P < 0.001). Calculated using CNCPS, losses were similar (P > 0.05) between grass and alfalfa (5.8 vs. 6.2% of GEI, respectively). Carbon dioxide production per unit DMI did not differ between pasture types, irrespective of method used to estimate intake (alkanes or CNCPS). The method used to predict intake can have a major influence on calculated values when methane emissions are expressed as a percentage of GEI in grazing ruminants. At each site, CH4 emissions and in vitro digestibility of the forage were influenced by the composition of the stand and the maturity of the forage at the time of harvest. Key words: Alfalfa, grass, grazing, legume, methane emissions
Effects of raising lambs in a cold or a warm environment on animal performance and carcass traits
Authors: Vachon M. , Morel R. , Cinq-Mars D.
Published: April 2011

A 2 x 2 x 2 factorial arrangement was conducted over two consecutive winters to compare growth and carcass traits of ram and ewe lambs in a cold or warm environment (noninsulated, unheated vs. an insulated and heated barn with minimum inside temperature (T) between 5 and 10°C). Each winter, 14 pairs of lambs of each sex were randomly allocated to either a cold or warm environment (average weight of 23.8 kg ± 0.6 and 22.4 kg ± 2.0 in 2003 and 2004, respectively). They were fed hay and concentrate ad libitum until they reached 42 to 48 kg body weight (BW) when they were slaughtered. Carcass traits were then evaluated. The average temperature in the cold environment was -7.49 and -4.74°C in 2003 and 2004, respectively, vs. +6.25 and +10.50°C, respectively, in the warm environment. There were no differences (P > 0.05) in growth performance and carcass traits between lambs raised in a cold or a warm environment. However, there was a tendency for lambs raised in a cold environment to have higher average daily gain (ADG) (P = 0.06) and to take less time to market (P = 0.09). Results suggest that it is possible to raise lambs in a cold environment without having any detrimental effect on performance and carcass quality. Key words: Lamb, environment, cold, performance, growth, carcass
Apparent and true total tract digestibility of phosphorus in field peas (Pisum sativum L.) by growing pigs
Authors: Stein H. H. , Boersma M. G. , Pedersen C.
Published: April 2011

The apparent (ATTD) and true (TTTD) total tract digestibility of P in field peas were measured using growing pigs. Two diets based on field peas without or with microbial phytase were formulated. A P-free diet was also formulated to measure endogenous losses of P. Results of the experiment showed that the ATTD and TTTD of P in field peas with microbial phytase (65.9 and 72.3%, respectively) were greater (P < 0.01) than in field peas without microbial phytase (55.0 and 60.8%, respectively). The addition of microbial phytase to field peas also reduced (P < 0.01) the excretion of P in the feces (from 5.77 to 4.09 g/5 d). Key words: Digestibility, endogenous losses, field peas, phosphorus, pig
The performance of early-weaned piglets following transport: Effect of season and weaning weight
Authors: Wamnes S. , Lewis N. J. , Berry R. J.
Published: April 2011

Two groups of 48 Cotswold piglets weaned at 17 ± 1 d of age were assigned to road or simulated transport during summer or winter. Following transport [Control (<20 min), 6 h, 12 h or 24 h], piglets were grouped by weaning weight (light, medium and heavy) in pens of four. Body weights were recorded on days 1–8, 10, 12 and 14. From an average weaning weight of 6.28 ± 0.09 kg, piglets lost on average 0.4 ± 0.1 kg. The minimum weight of 5.88 ± 0.1 kg was reached 2.24 ± 0.13 d post weaning and weaning weight was recovered at 3.55 ± 0.16 d post weaning. As transport duration increased from 6 to 24 h, total weight loss increased from 0.33 to 0.45 ± 0.022 kg (P < 0.01). Piglets transported by road in winter had a longer growth check (4.08 vs. 3.18 ± 0.18 d, P < 0.05) showed reduced percent ADG (5.37 vs. 6.61 ± 0.26%, P < 0.05) and lower feed conversion efficiency (FCE) (0.87 vs. 0.96 ± 0.01 kg, P < 0.01) than piglets transported by road in summer. Heavy piglets continued to lose weight longer than light piglets (2.26 vs.1.7 ± 0.16 d, P < 0.02), although relative weight loss was not affected. During winter piglets exposed to road transport required more time to recover their weaning weight than piglets exposed to simulated transport (4.08 vs. 3.04 ± 0.18 d, P < 0.05). While weaning is a confounding effect, these results suggest that longer transport (>12 h) and transport in winter may cause additional stress to early-weaned piglets. Some factors of road transport in winter, possibly driving differences or fluctuating temperatures also negatively affected piglet recovery from weaning. Key words: Early weaning, transport, pigs, season
Comparison of alfalfa and mixed alfalfa-sainfoin pastures for grazing cattle: Effects on incidence of bloat, ruminal fermentation, and feed intake
Authors: Wang Y. , Berg B. P. , Barbieri L. R. , Veira D. M. , McAllister T. A.
Published: April 2011

Grazing experiments were conducted over two years to evaluate the effects of incorporating sainfoin (Onobrychis viciifolia) into alfalfa (Medicago sativa) pasture on bloat, ruminal fermentation, and feed intake. Pastures of alfalfa (Alf) and alfalfa-sainfoin (AS) were established by cross-seeding (in 1998) or parallel-seeding in (1999) sainfoin into strip-seeded alfalfa. The pastures were used in grazing studies in 1999 and 2000. For periods of 4 or 5 d, 12 ruminally cannulated Jersey steers were turned out into pastures from 0830 to 1430 daily (without access to water) then were moved to a fenced area (with free access to water but no feed) until the next morning. Feed intake during grazing was estimated using alkane markers, development of bloat was assessed, and ruminal fluid (RF) fermentation properties were determined. Incidence of bloat on first-growth pastures grazed at early bloom in 1999 was unaffected by sainfoin (at 8.3%, DM basis) but was reduced by 80% (P < 0.001) in AS pasture compared with Alf, when grazed at full-bud in 2000 (12.1% sainfoin). With re-growth forage, bloat incidence was decreased by 77% (P < 0.05) on pasture containing 35% sainfoin, but treatment effect was not observed on pastures containing < 23% sainfoin. Incidence of bloat was reduced as the proportion of sainfoin in herbage mass increased. In 2000, ruminal ammonia concentrations were reduced (P < 0.05) with mixed forage containing ≥ 12.1% sainfoin, compared with Alf. Protozoal numbers, RF viscosity, and total volatile fatty acids (VFA) were unaffected by sainfoin in the forage, but acetate:propionate ratios were consistently reduced (P ≤ 0.036). Extracellular polysaccharide-degrading enzyme activities in RF were increased (carboxymethylcellulase and β-glucanase, P ≤ 0.034; xylanase, P = 0.008 and 0.08) by sainfoin at ≥ 12.1%, and proteolytic activities (intracellular and extracellular) were reduced (P ≤ 0.01). Enzyme activities were unaffected by sainfoin at ≤ 9.1%. Sainfoin did not affect (P ≥ 0.202) organic matter intake from any of the pastures surveyed. Sainfoin was more effective for reducing bloat when cattle were grazing first growth pastures than when grazing re-growth. Including 35% sainfoin in mixed alfalfa-sainfoin pastures reduced, but did not eliminate, bloat in beef cattle and enhanced protein utilization by decreasing proteolytic activity. Feed efficiency may be improved through associative effects of the two forages. Key words: Alfalfa, beef cattle, feed intake, grazing, pasture bloat, sainfoin
Omega-3 enriched broiler meat: The influence of dietary α-linolenic-ω-3 fatty acid sources on growth, performance and meat fatty acid composition
Authors: Azcona Jorge O , Schang Marcelo J , Garcia Pilar T , Gallinger Claudia , Ayerza Jr. Ricardo , Coates Wayne
Published: April 2011

Western diets are typically low in ω-3 fatty acids, and high in saturated and ω-6 fatty acids. There is a need to increase dietary ω-3 fatty acid content. Chia (Salvia hispanica L.) has the highest botanical source of alpha-linolenic acid (ALA) known, and recently has been receiving more attention because of this. Feeding ALA to animals has been shown to increase the ω-3 fatty acid content of the foods they produce, and hence offers consumers an easy way to increase their intake of ω3 fatty acids without altering their diet. Broilers were fed rapeseed, flaxseed, chia seed and chia meal to assess the ability of these feed ingredients to increase the ω-3 fatty acid content of the meat, and also to determine whether any negative effects on bird production would arise. Flaxseed produced significantly (P < 0.05) lower body weights, weight gains and poorer conversion ratios than did the other feeds. Except in the case of the chia meal with the dark meat, the chia seed significantly (P < 0.05) reduced the saturated fatty acid (SFA) content of the white and dark meats compared with the control diet. Adding ALA increased the ALA, LCω-3 fatty acid and total polyunsaturated fatty acid (PUFA) ω-3 fatty acid content of both meat types, except in the case of the white meat of the birds fed rapeseed. Chia seed gave the highest total PUFA ω-3 increase, yielding 157 and 200% increases for the dark and white meat, respectively, compared with the control. The ω-6:ω-3 and SFA:ω-3 ratios dramatically improved in both types of meat when chia seed, chia meal or flaxseed was added to the diet. The study also showed that not all ALA-rich seeds are biologically equivalent sources in terms of producing ω-3 enriched broiler meat. Chia proved to be superior to the other sources examined in this trial. Key words: Chia seed, flaxseed, rapeseed, omega-3, alpha-linolenic, broiler meat, fatty acid
Phenotypic study of body condition scores in Canadian dairy cattle
Authors: Moro-Méndez J. , Cue R. I. , Monardes H. G.
Published: April 2011

The objective of this study was to characterize body condition score (BCS) in dairy cattle recorded under commercial conditions in Quebec. There were 354 958 BCS records from Holstein cows and 15 334 records from Ayrshire cows available, from first to fifth parity, recorded by producers using a scale of 1 to 5. A classification model was fitted including fixed effects of herd, year of calving, month of calving, age at calving, and days in milk (DIM); another model substituted the Wilmink function on days in milk to model lactational BCS curves. Both models used the spatial power covariance structure to account for correlation between BCS recorded on the same cow along the lactation and were fitted using the Mixed procedure of SAS software (version 9.1.3). Body condition score was significantly affected by month of calving, age at calving and DIM. Average BCS (SD) for Holstein cows from first to fifth lactation were: 2.95 (0.46), 2.90 (0.53), 2.93 (0.56), 2.94 (0.57), and 2.93 (0.57), respectively; the estimates for Ayrshire cows from first to fifth lactation were: 2.99 (0.47), 3.06 (0.54), 3.15 (0.56), 3.11 (0.57), 3.13 (0.58). Lactation curves for BCS were generated for each breed and parity. The routine collection of BCS in individual cows is recommended to ensure close monitoring of energy balance during the lactation. The BCS information analyzed in this study is suitable for modeling changes throughout the lactation with the application of the Wilmink function. Key words: Body condition score, Canadian dairy cattle
Pancreatic mass, cellularity, and α-amylase and trypsin activity in feedlot steers fed increasing amounts of a high-moisture-corn based diet
Authors: Swanson K. C. , Kelly N. , Wang Y. J. , Ko M. , Holligan S. , Fan M. Z. , McBride B. W.
Published: April 2011

Twenty-four yearling beef steers (initial BW = 467 ± 3.6 kg), predominately of Angus breeding, were used in a randomized complete block design to determine the effect of dietary intake on pancreatic cellularity, mass, and α-amylase and trypsin activity. Steers were individually fed a high-moisture corn-based diet at 1.25, 1.50, 1.75, and 2.00% of BW (DM basis) using Calan gates. After 28 d on treatment, the heaviest steer from each dietary treatment was slaughtered per wk and pancreata collected. Average daily gain (kg) and pancreatic weight (g) increased linearly (P ≤ 0.01) with increasing DM intake. Pancreatic DNA and RNA concentration and content, and RNA:DNA and protein:DNA did not differ (P > 0.05) between treatments. This suggests that the observed increase in tissue weight was due to increases in both cell size and number. Total pancreatic α-amylase activity (kU pancreas-1) increased linearly (P = 0.04) with increasing DM intake. These data indicate that total pancreatic α-amylase activity (kU pancreas-1) linearly increases with increasing intake of a high-moisture corn-based finishing diet and that dietary intake-dependent changes in total pancreatic α-amylase activity are primarily due to changes in pancreatic weight rather than changes in the concentration of pancreatic α-amylase activity (U g-1 pancreas). Key words: Beef cattle, pancreas, α-amylase, trypsin, feed intake
Evaluation of leaf physiological and biochemical traits during senescence of the wheat core collection in the southwest of China
Authors: Shu Kai , Luo Pei G , Zhang Huai Y , Yan Ben J , Zhang Jie , Zhang Huai Q , Ren Zheng L
Published: April 2011

Agronomical, physiological, and biochemical analysis of the Chinese wheat (Triticum aestivum L.) core collection revealed abundant variation in the indices examined, both within and between ecotype regions. The genotypes from the Yellow-Huai Rivers (YH) region, the Middle and lower reaches of the Yangtze River (MY) region and the Southwest China (SWC) region showed good adaptation as measured by heading date, malondialdehyde content (MDA), and superoxide dismutase (SOD) and catalase (CAT) activities and would have good potential for wheat improvement in SWC. Key words: Adaptability, core collection, diversity, leaf traits, southwest China, wheat
Adaptation of alternative pulse and oilseed crops to the semiarid Canadian Prairie: Seed yield and water use efficiency
Authors: Angadi S. V. , McConkey B. G. , Cutforth H. W. , Miller P. R. , Ulrich D. , Selles F. , Volkmar K. M. , Entz M. H. , Brandt S. A.
Published: April 2011

Diversification and intensification of the cropping systems in the traditional wheat-fallow area of the semiarid Canadian prairie is necessary to improve sustainability. Selection of alternate crops to include in cropping systems requires information on production risks with different climate regimes. To understand water use/yield relationships of alternate crops, three pulse crops (leguminous grain crops) [chickpea (Cicer arietinum L.), pea (Pisum sativum L.) and lentil (Lens culinaris Medik.)], three oilseed crops [canola (Brassica napus L. and B. rapa L.) and mustard (B. juncea L.)], and one cereal crop [wheat (Triticum aestivum L.)] were studied under varying water regimes: during 1996–1998 under well-watered, rainfed, imposed drought conditions, and in 2001 under rainfed conditions. Generally, the relative ranking between crops for water use was maintained across water regimes, such that the crops separated into three general groups of water users (high: wheat, B. napus, mustard; medium: chickpea, B. rapa, lentil; low: pea) with pea using an average of 34 mm and 13 mm less water than high- and medium-water-using crop groups, respectively. The exceptions included desi chickpea, which tended to use less water and B. rapa, which tended to use more water relative to the other crops as water use decreased. Generally, pea and wheat produced the most grain and biomass, had the highest water use efficiency, and had moderately high to high harvest indices. Wheat and pea are well adapted to variable rainfall amounts inherent in semiarid climates. Desi chickpea and lentil produce good grain yields under dry conditions, and grain yields relative to those of other crops can be increased by some drought stress, especially mid- to late-season stress. Therefore, because of their relatively good performance under water-stressed conditions, they are also well adapted to semiarid climates. Conversely, the Brassica oilseeds yielded relatively poorly compared with wheat and pulse crops under severe water-stressed conditions, so they are not as well adapted to the semiarid climate. In 2001, grain yield of wheat and pulses seeded on stubble was ≥30% of the yield on fallow, whereas stubble-seeded Brassica oilseeds yielded only about 10% of that on fallow. Compared with stubble seeding, production of Brassica oilseeds on fallow will decrease the risk of very low yields under drought. We found little indication that mustard was more drought tolerant than B. napus. Key words: Yield, water use efficiency, oilseeds, pulse, semiarid prairie
Reduced herbicide rates provide acceptable weed control regardless of corn planting strategy in Ontario field corn
Authors: Sikkema Peter H , Nurse Robert E , Welacky Tom , Hamill Allan S
Published: April 2011

A study was conducted at three locations in central-southwestern Ontario from 1996 to 1998 to determine if corn (Zea mays L.) productivity and weed control can be maintained when row spacing is narrowed, crop density is increased and herbicide rate is reduced. Post-emergence herbicides [(rimsulfuron + nicosulfuron) plus (dicamba + atrazine)] at four rates (full label rate (1×), 75% full rate (0.75×), 50% full rate (0.5×) and an untreated check) were tested at three corn row-spacings (38, 50, and 75 cm) and two plant densities (75 000 and 90 000 plants ha-1). Herbicide application at the 0.5× rate versus an untreated check still allowed for increased corn yield (8.3 vs. 4.9 t ha-1) and decreased weed dry weight (9.4 vs. 240.4 g m-2), weed plant density (11.0 vs. 52.6 plants m-2) and weed seed density (239 vs. 14 241 seeds m-2). Corn LAI was not affected by decreasing herbicide rate. In this study, increasing corn plant density and decreasing corn row spacing were not factors in reducing herbicide inputs in corn cropping systems in central-southwestern Ontario. Herbicide rate could be reduced by up to 50% while maintaining corn grain yield, weed density, weed dry weight, and the number of weed seeds entering into the soil seed bank. Implementation of these reduced rates will help to increase the economic and environmental sustainability of the Canadian field corn industry. Key words: Agricultural systems, crop yield, seeding rate, sustainability, weed biomass
Who’s invading what? Systems thinking about invasive species
Authors: Larson B. M. H.
Published: April 2011

While invasive plant species have dramatic and varied effects, this paper examines the focus of this symposium on their “threat to native biodiversity and ecosystems”. This claim implies that there is (i) an enduring something, (ii) it is native, and (iii) it is under threat from invasive species. I examine these implications in turn, first considering the role of the observer in invasion biology, particularly in preferring a nature characterized by stability rather than flux. Second, I examine the concept of “native” given that humans are thoroughly embedded within natural ecological systems. Third, I demonstrate how our exclusion of humans conditions us to consider invasive species a primary threat rather than one among many interacting causal agents of global change; in particular, recent evidence indicates that these agents, which include human-caused disturbances and global warming (not to mention human population growth and global trade), may overwhelm the effects of invasive species per se. For these and other reasons, some ecologists have argued that ecological change is inevitable and that our concerns about invasive species are unjustified. I discuss these issues and suggest ways for ecologists to conduct engaged research through appropriate advocacy and engagement with stakeholders dealing with local invasive species. Key words: Advocacy, culture, philosophy of nature, sociology of science
Yield and nutritive value of the spring growth of an ageing timothy sward
Authors: Bélanger Gilles , Tremblay Gaëtan F , Mongrain Danielle
Published: April 2011

The decline in productivity of forage grasses with age since establishment has been recognised for several years, but this yield reduction and its consequences on nutritive value have not been studied in timothy (Phleum pratense L.). Our objective was to characterize the dry matter (DM) yield and nutritive value during spring growth of an ageing timothy sward grown under non-limiting N conditions. A timothy sward, seeded in 1998, was harvested at four developmental stages (stem elongation, early heading, late heading, and early flowering) during spring growth from 1999 to 2005. The average DM yield observed in production years 5, 6, and 7 was 43% of that measured in the first 4 production years when timothy was harvested at stem elongation or early heading, 52% when harvested at late heading, and 74% when harvested at early flowering. The yield potential of timothy during spring growth decreased with ageing at a rate of 0.66 and 0.91 Mg DM ha-1 yr-1 with harvests at early and late heading, respectively. The nutritive value of timothy harvested at stem elongation was greater in older (production years 5, 6, and 7) than in younger (first 4 production years) swards as indicated by in vitro true digestibility of DM (+ 48 g kg-1 DM), in vitro digestibility of NDF (+ 77 g kg-1 NDF), and neutral detergent fibre (NDF) concentration (-62 g kg-1 DM); this difference, explained mostly by the lower DM yield of older swards, disappeared when timothy was harvested later on in the growth cycle. Rates of change in nutritive value observed during the phase of reproductive development in spring growth were, therefore, greater in older than in younger swards. Our results demonstrate clearly the decline in timothy productivity with age and its consequences on nutritive value. Key words: Phleum pratense, harvesting year, stages of development, yield, digestibility
Puroindoline allele diversity in Canadian and northern US hard spring wheat varieties differing in kernel hardness
Authors: Matus-Cádiz M. A. , Pozniak C. J. , Hucl P.
Published: April 2011

Kernel hardness, one of the most important factors in determining the end-use suitability of wheat (Triticum aestivum L.), is largely influenced by puroindoline proteins a (PINA) and b (PINB). Soft texture is wildtype (Pina-D1a/Pinb-D1a) with hard texture being determined by either Pina-D1 gene deletion or point mutations in Pinb-D1a. The objectives of this study were to determine kernel hardness indices (HI) and Pina-D1/Pinb-D1 allelic diversity in a diverse set of 81 Canadian (representing eight wheat classes) and 49 US hard spring wheat varieties. Varieties were grouped into two experimental sets grown in replicated trials in 2004–2006 at Saskatoon, SK. Variation existed among varieties with HI means ranging from 21.7 (CDC Zorba) to 72.7 (AC Morse) in exp. 1 and from 25.0 (HY320) to 66.1 (Norlander) in exp. 2. Only AC Andrew, CDC Zorba, and Red Fife were soft kernel textured and carried the wildtype Pina-D1a/Pinb-D1a alleles. The majority of Canadian varieties were Pina-D1a/Pinb-D1b (69%), while a greater frequency of US varieties was Pina-D1b/Pinb-D1a (55%). Only four varieties, all from Quebec-based breeding programs, carried the Pinb-D1c allele. On average, varieties with the Pina-D1b allele had significantly harder kernels than those carrying the Pinb-D1b mutation. Durum wheat (T. turgidum L. var durum) varieties, included as hard-kernelled controls, possessed significantly harder kernels (average HI = 71.2) than spring wheat varieties with Pina-D1b (65.3). Varieties carrying Pina-D1b (null PINA) were harder than those carrying hardness mutations at the Pinb-D1 locus, but considerable overlap in hardness was evident among genotypic classes. This work represents the first extensive Pin genotyping combined with HI phenotyping survey of Canadian wheat varieties, which is expected to aid breeders in understanding how Pina-D1/Pinb-D1 allele composition is currently associated with kernel hardness across Canadian wheat classes. Key words: Triticum aestivum, kernel hardness, puroindolines