bluuebunny/crossref_metadata_2025 huggingface dataset:
A new species of Androprosopa from Mexico (Diptera: Thaumaleidae)
Authors: Sinclair Bradley J. , Huerta Herón
Published: April 2011

Two species of Androprosopa Mik are reported from Mexico, one of which is newly described (A. zempoalasp. nov.). This new species is related to a small group of western Nearctic species defined by a pair of posterolateral hook-like epandrial processes.
Application of pig growth models in commercial pork production
Authors: de Lange C. F. M. , Marty B. J. , Birkett S. , Morel P. , Szkotnicki B.
Published: April 2011

Pig growth models can be useful tools for identifying optimum management strategies for individual grower-finisher pig units, by integrating knowledge of nutrient utilization for growth and animal-environment interactions into one system. In addition, these models can be used to demonstrate basic principles of nutrient utilization for growth in the pig, to examine “what-if” scenarios, to aid in the development of pig breeding programs and to develop effective research programs. Models used in commercial pork production should represent the biology of growth in the pig and should be flexible, so that they can be focused easily on the needs and special conditions pertaining to particular growing–finishing pig units. For proper application of pig growth models in practice, pig units should be characterized reasonably accurately. This applies in particular to the upper limit to body protein deposition that pigs can achieve under practical conditions, feed intake at various stages of growth and the alternative feeding strategies that can be considered. Some illustrative examples of the commercial application of a pig growth model under Canadian conditions are provided. Key words: Pig, growth, models, application
Effects of pre-slaughter administration of oral calcium gel to beef cattle on tenderness
Authors: Duckett S. K. , Andrae J. G. , Pritchard G. T. , Skow T. A. , Cuvala S. L. , Thorngate J. H. , Sanchez W. K.
Published: April 2011

The effects of pre-harvest administration of oral calcium gel to beef cattle on longissimus pH, calpain activity, and tenderness were examined. Thirty steers (539 kg) were randomly assigned to one of the following treatments: control (CON, n = 15) and calcium gel administered (CA, n = 15). At 3 to 6 h prior to slaughter, the calcium gel steers were dosed via a rumen tube with calcium propionate (150 g of calcium and 630 g propionate) and propylene glycol (600 g) in a liquid suspension. Calcium gel administration prior to slaughter increased (P < 0.05) m-calpain and m-calpain activity (caseinolytic activity per gram of muscle) with no change (P >0.05) in calpastatin activity. Total mineral (%) and calcium (mg g–1) contents of the longissimus muscle were greater (P <0.05) for CA than CON. Steaks from CA steers had Warner-Bratzler shear force (WBS) values lower (P < 0.05) than CON after4 and 7 d of aging. No differences (P > 0.05) were noted in WBS values at days 2, 14, or 28 of aging between the treatments. Sensory panel ratings were higher (P < 0.05) for tenderness of CA steaks than CON after aging for 7 d, and juiciness and flavor ratings were similar (P > 0.05). Pre-harvest calcium gel administration elevated longissimus muscle calcium content, increased calpain activity, and accelerated postmortem aging to improve tenderness. Key words: Beef, calcium, tenderness, calpain
Feeding motivation in swine: Relation with insulin, glucose and free fatty acids in portal and jugular blood, and involvement of cholecystokinin
Authors: Farmer C. , Roy N. , Rushen J. , Robert S.
Published: April 2011

The control of feeding motivation was studied in eight castrated male pigs (92.9 ± 1.5 kg) surgically fitted with jugular and portal vein catheters. The first part of the experiment was set up as a cross-over design. Two weeks after surgery, four pigs were fasted for 24 h (FAST) while the remaining four were fed ad libitum (CTL). Three days later, the same procedure was repeated with the treatments reversed. Blood samples were collected every 4 h during the first 16 h of these two 24-h periods. After each 24-h period, pigs were subjected to a feed motivation test during which blood samples were obtained every 5 min for 60 min for CTL pigs and until 30 min after cessation of eating in FAST pigs. Three days later, the second part of the experiment was conducted. Five of the eight pigs were fasted for another 24 h, injected i.v. with 70 μg kg–1 BW of a cholecystokinin (CCK) receptor antagonist (MK-329), and subsequently subjected to a feed motivation test. Insulin, glucose and FFA concentrations were greater (P < 0.001) in portal than jugular blood. Fasting decreased insulin concentrations in both portal and jugular blood, decreased glucose in portal blood only, and increased FFA in jugular blood only. The number of pushes (P < 0.05), duration of eating (P < 0.001) and amount of feed eaten during the feed motivation test (P < 0.01) were all increased by fasting, and were further increased with MK-329 injection. Results indicate that CCK is involved in the control of satiety in pigs and that concentrations of insulin, glucose and FFA in the jugular vein may not always be representative of concentrations in the portal vein. Key words: Swine, insulin, glucose, cholecystokinin, feeding motivation, fast
Effect of the dietary supplementation of fructooligosaccharides and Bifidobacterium longum to early-weaned pigs on performance and fecal bacterial populations
Authors: Estrada A. , Drew M. D. , Van Kessel A.
Published: April 2011

Two experiments were conducted to evaluate the effect of administration of fructooligosaccharides (FOS) and Bifidobacterium longumon growth performance and fecal bacterial populations in pigs weaned at 18 d of age. In exp. 1, two groups of 20 pigs each were fed diets containing 0 or 0.5% FOS for 21 d. On days 1 and 3, pigs receiving FOS were administered an oral dose of 1010 B. longumcells. During week 1, average daily gain was higher and feed efficiency was improved (P < 0.05) in pigs fed FOS and bifidobacteria relative to the control. On day 7, supplemented pigs had reduced numbers of total anaerobes and clostridia, and increased numbers of bifidobacteria in faeces (P < 0.05). In exp. 2, 80 pigs were divided into four groups of 20 animals each in a 2 x 2 factorial design. Main effects included FOS supplementation (0 or 0.5% of diet) and B. longum supplementation (0 or 107 cells per gram feed). FOS supplementation reduced growth while B. longum supplementation increased growth (P< 0.05). On days 12 and 19, serum insulin-like growth factor I (IGF-I) was reduced with FOS supplementation and increased with B. longum supplementation (P < 0.05). It was concluded that the continuous administration of bifidobacteria provided a beneficial effect on growth parameters studied in this experiment. Key words: Pigs, fructooligosaccharides, bifidobacteria, Bifidobacterium longum, performance
Effect of dietary ideal amino acid ratios, and supplemental carbohydrase in hulless-bar ley-based diets on pig performance and nitrogen excretion in manure
Authors: Grandhi R. R.
Published: April 2011

Two experiments were conducted, using a total of 224 (112 barrows + 112 gilts) crossbred pigs, to determine the effect of dietary ideal amino acid ratios, and supplemental carbohydrase in hulless barley (HB) diets, on pig performance and N excretion in manure. The four experimental grower and finisher diets were 1) a covered-barley (CB) control diet, 2) a HB (cv. Condor) diet, 3) same as diet 2 except that the soybean meal was replaced with supplemental lysine, threonine, methionine and tryptophan, to provide ideal amino acid ratios of 0.65 for threonine to lysine and 0.30 for methionine to lysine, and 4) same as diet 3 with supplemental carbohydrase (RonozymeTM W) enzyme at 350 g t–1. All diets were fed ad libitum as pellets with free access to drinking water. The average daily gain (ADG) was not different (P > 0.10) between diets 1 and 2, or among diets 2, 3 and 4 during the grower or finisher periods. The feed conversion efficiency was higher (P < 0.01) for diets 3 and 4 than for diet 2 during the grower period, but it was higher (P < 0.05) only for diet 4 than diet 2 during the finisher and combined grower-finisher periods. Backfat thickness, carcass index and dressing % were not different (P > 0.10) among the diets. The absorption of dry matter (88.9 vs. 83.7%) and energy (87.8 vs. 84.1%) was greater (P < 0.05) for diet 2 than diet 1. The excretion of faecal dry matter was 31.6% lower (P < 0.01) for diet 2 than diet 1 during the finisher period. The N excretion was 22.0% lower in pigs fed diet 3 than diet 2. Ammonia, carbon dioxide and hydrogen sulphide concentration in stored manure were not different (P > 0.10) among the diets, but ammonia production was positively correlated with urinary N excretion. These results indicated that feeding HB diets with supplemental amino acids minimises the excretion of both faecal dry matter and N with no adverse effect on the performance of lean-genotype pigs. Key words: Pigs, hulless-barley, amino acids, carbohydrase, nitrogen, manure
Effects of feeding different levels of conjugated linoleic acid and total oil to pigs on live animal performance and carcass composition
Authors: Dugan M. E. R. , Aalhus J. L. , Lien K. A. , Schaefer A. L. , Kramer J. K. G.
Published: April 2011

The effects of feeding different dietary levels of conjugated linoleic acid (CLA) and total oil (TO) were evaluated using 216 barrows fed from 36 to 115 kg body weight. A 3 × 2 factorial design was used with three levels of dietary CLA (0, 0.25, and 0.5%), two levels of dietary TO (2 and 5% made up with canola oil) and 12 pens of three barrows fed per diet. Pigs on all diets gained weight at the same rate from 0 to 4 wk (36 to 61 kg) and from 4 wk to slaughter (61 kg to 115 kg) (P > 0.05). Pigs fed 5% versus 2% TO had 6.6% lower feed intake from 0 to 4 wk (P = 0.02) and 5.9% lower feed intake from 4 wk to slaughter (P < 0.003), while feeding CLA had no effect on feed intake (P = 0.70). A CLA by TO interaction for feed intake was not found for 0 to 4 wk but from 4 wk to slaughter a tendency for an interaction (P = 0.06) was found indicating 0.25% CLA may depress feed intake at 2% TO while stimulating intake at 5% TO. Increasing TO and CLA increased the lean content in commercial cuts by 1.6% (P = 0.06) and 2.7% (P = 0.008), respectively. A CLA by TO interaction (P = 0.012), however, indicated CLA was less effective at increasing lean when added to 5% TO diets than to 2% TO diets, with pigs fed the 0% CLA/2% TO diet yielding 5% less lean than pigs fed any of the other diets (P < 0.05). Interestingly, a main effect for TO was not found for subcutaneous fat (SCF), but adding CLA reduced SCF (6.6%; P = 0.002). Again, a CLA by TO interaction (P = 0.008) indicated adding CLA was less effective at reducing SCF in 5% TO than 2% TO diets, with pigs fed the 0% CLA/2% TO diet having 9.7% more SCF than pigs fed any of the other diets (P < 0.05). The difference in effectiveness of CLA at different TO levels might be due to dilution of CLA by canola oil fatty acids and/or canola oil having fat to lean repartitioning effects of its own. A comparison of fats and oils with differing chain lengths and degrees of saturation would, therefore, be of interest to further define their potential differential effects on growth and metabolism. Key words: Pig, pork, swine, conjugated linoleic acid, CLA, canola oil
The effect of dietary level of soybean oil and palm oil on apparent ileal amino acid digestibility and postprandial flow patterns of chromic oxide and amino acids in pigs
Authors: Albin D. M. , Smiricky M. R. , Wubben J. E. , Gabert V. M.
Published: April 2011

A study was conducted to evaluate the apparent ileal digestibilities of amino acids in pigs (initial weight 78 kg) fed diets supplemented with either soybean or palm oil, at either 100 or 200 g kg–1 diet. A control diet with no added fat was also evaluated. All diets contained 5 g chromic oxide kg–1. The pigs were surgically fitted with a simple T cannula at the distal ileum, and were allowed to adapt to each experimental diet for 5 d. This was followed by 1 d of continuous collection of ileal digesta between feedings, and a second day of continuous collection separated into six 2-h postprandial time blocks to determine postprandial flow patterns of chromic oxide and amino acids. The apparent ileal leucine and arginine digestibilities were improved (P < 0.05) by 3.8 and 3.6%, respectively, with 200 g soybean oil kg–1 diet. Linear improvements (P < 0.05) were found in the apparent ileal digestibilities of serine, histidine, arginine, tyrosine, and leucine when 100 and 200 g soybean oil kg–1 diet were supplemented to the control diet, and for serine, histidine, arginine, and phenylalanine with the addition of 100 and 200 g palm oil kg–1 diet. Quadratic responses (P < 0.05) were found in the apparent ileal digestibilities of isoleucine and leucine with the addition of 100 and 200 g palm oil kg–1 diet. The postprandial flow patterns of chromic oxide and amino acids were very stable despite the different dietary treatments. Also, amino acid digestibility coefficients determined at different postprandial sampling times had low variability. In conclusion, the addition of high levels of soybean and palm oil to a semipurified swine diet increased the apparent ileal digestibilities of some amino acids. Also, the two fat sources affected some apparent ileal amino acid digestibility coefficients differently. Key words: Pigs, ileal, amino acid digestibility, fat, postprandial flow patterns
Welfare of farmed silver foxes (Vulpes vulpes) housed in sibling groups in large outdoor enclosures
Authors: Ahola L. , Harri M. , Mononen J. , Pyykönen T. , Kasanen S.
Published: April 2011

The aim of the present study was to evaluate the effects of housing farmed silver foxes in large outdoor enclosures with less abundant human contacts on some behavioural and physiological welfare parameters. Farmed silver fox cubs were housed either singly in traditional fox cages or in sibling groups in enclosures. Mass of adrenals, serum cortisol level after adrenocorticotrophic hormone (ACTH) administration and stress-induced hyperthermia, as well as 24-h activity measures and the number of bite scars, were used to draw conclusions on the welfare effects of housing farmed silver foxes in the two experimental housing systems.

The housing system had significant effects neither on the serum cortisol level after ACTH administration nor on the mass of adrenals. This result shows that intra-group social tension and non-habituation to humans, both leading to increased long-term stress in foxes housed in large outdoor enclosures, can be partly overcome by, respectively, altering the group composition and keeping the cubs for a longer time in cage conditions with close human contact. However, a large number of bite scars and increased stress-induced hyperthermia (SIH) in the foxes housed in enclosures, indicating an acute stress response to the presence of humans, may not be overcome. Furthermore, the 24-h activity rhythm changed in the foxes housed in large enclosures resembling, especially in November, the nocturnal activity pattern of the wild red fox, indicating that the foxes in enclosures became at least to some extent feral. Key words: Activity rhythm, aggression, hypothalamic-pituitary-adrenal axis, human-animal relation, stress-induced hyperthermia, Vulpes vulpes
Prevalence of Giardia and Cryptosporidium andersoni and their effects on performance in feedlot beef cattle
Authors: Ralston B. J. , Cockwill C. L. , Guselle N. J. , Van Herk F. H. , McAllister T. A. , Olson M. E.
Published: April 2011

Sixty individually housed Charolais crossbred steers originating from one ranch source had a 12-d (days 0–12) adaptation period in their pens to adjust to their ration and surroundings, followed by two consecutive backgrounding periods (85.5% roughage, 12% concentrate rations) with durations of 84 d (days 13–97) and 63 d (days 98–153), respectively. Steers had a 21-d adaptation period (days 154–174), followed by a 77-d (days 175–257) finishing period (20% roughage, 75% concentrate ration). Fecal samples and animal weights were collected from each steer every 28 d initially, then every 21 d during a test duration of 257 d. Feed weigh-backs were performed weekly for each steer. Fecal samples were processed, and Giardia duodenalis cysts and Cryptosporidium andersoni oocysts were counted. ADG, DMI and FE were calculated for each of the periods (Backgrounding Period 1, Backgrounding Period 2, Finishing Period 3 and Overall). Overall prevalence of C. andersoni and G. duodenalis was 85 and 82%, respectively. There was a decrease (P < 0.05) in the percentage of G. duodenalis infected steers from day 132 to the completion of the trial. The percentage of C. andersoni infected steers decreased (P < 0.05) from day 97 to the completion of the trial (day 257). Shedding of G. duodenalis cysts and C. andersoni oocysts in the feces was intermittent throughout the trial period. A comparison between the ADG, DMI and FE of G. duodenalis infected and non-infected steers demonstrated no overall differences (P > 0.05). A similar comparison between C. andersoni infected and non-infected steers showed no overall difference (P > 0.05) with the exception of a lower (P < 0.05) DMI for infected steers. The degree of Giardia or C. andersoni infection observed in the present study did not effect DMI, ADG or FE of feedlot steers. Key words: Giardia, Cryptosporidium andersoni, feedlot performance, cattle
An evaluation of models predicting beef cattle performance using data from bulls on performance testing
Authors: Duynisveld J. L. , Charmley E.
Published: April 2011

Data from 372 bulls on performance testing were used to compare predictions of intake and gain with observed performance when the forage-to-concentrate ratio (F:C) in the ration ranged from 57:43 to 45:55. Predictions were derived from the National Research Council (NRC 1996) and the Agricultural and Food Research Council (AFRC 1993) models. Increasing the F:C resulted in a decline in dry matter intake as a percent of body weight, but did not influence observed average daily gain (ADG). The NRC (1996) model increasingly under-predicted ADG as forage inclusion in the ration increased, whereas AFRC (1993) was a better predictor of daily gain as F:C increased. Contrary to predictions, inclusion levels of silage can be increased in totally mixed rations without compromising animal performance. Key words: Forage-to-concentrate ratio, bulls, performance, model
Lactational performance, nursing and maternal behavior of Upton-Meishan and Large White sows
Authors: Farmer C. , Palin M. F. , Sorensen M. T. , Robert S.
Published: April 2011

The growth of litters from 19 Upton-Meishan (UM) and 16 Large White (LW) sows was recorded from birth to weaning (25 d of age). Water and feed intake of sows were recorded. Suckling behavior was studied on days 5 and 20 of lactation. Milk yield was measured on day 22 and a milk sample was obtained the next day. Water intakes were similar (P = 0.947) for both breeds, yet UM sows consumed less feed throughout lactation (P = 0.0002). Average piglet (P < 0.05) and total litter (P < 0.001) weights were greater as of day 7 in UM compared to LW sows. Mean piglet weight on day 24 was 6.13 ± 0.16 kg for UM litters and 5.33 ± 0.33 kg for LW litters. Suckling interval was similar for UM and LW litters on day 5 (P = 0.533), but was shorter for UM litters on day 20 (41.4 ± 1.2 vs. 48.3 ± 2.8 min; P= 0.060). On day 22, daily milk yield corrected for actual suckling interval was greater (10.59 ± 0.47 vs. 8.03 ± 0.65 kg; P = 0.003) in UM sows. Milk from UM sows contained more fat (P= 0.042) and lactose (P = 0.005). In conclusion, the greater growth rate of piglets from UM sows is mainly due to a higher frequency of nursings and to greater energy content of milk. Key words: Sows, lactation, breed, Meishan, behavior, nursing
In vitro embryo production using ovaries removed from culled cows
Authors: Giritharan G. , Rajamahendran R.
Published: April 2011

The objective was to utilize in vitro maturation and fertilization to maximize embryo production from culled dairy cows. Ovaries were removed (via a colopotomy technique) from culled Holstein cows (n = 21) 2 d after standing estrus (T1), 2 d after treatment with 40 mg follicle stimulating hormone (FSH) given at standing estrus (T2), or at an unknown stage of the estrous cycle (T3).Treatment with FSH increased (P < 0.05) oocyte recovery rate (mean ± SEM, 14.6 ± 2.2, 25.4 ± 3.4, and 11.1 ± 2.6 oocytes ovary–1), for groups T1, T2 and T3, respectively, and the number of blastocysts obtained (1.6 ± 0.5, 4.4 ± 0.4 and 1.6 ± 0.6 blastocysts ovary–1). Culled dairy cows of high genetic merit are potential embryo donors, with an average of six to eight transferable embryos obtained from each FSH-treated cow. Key words: FSH treatment, oocyte recovery, IVM, IVF, culled cows
Small intestinal morphology and bacterial populations in ileal digesta and feces of newly weaned pigs receiving a high dietary level of zinc oxide
Authors: Li B. T. , Van Kessel A. G. , Caine W. R. , Huang S. X. , Kirkwood R. N.
Published: April 2011

A study was carried out to determine the effect of dietary supplementation of 3000 mg kg–1 zinc oxide (ZnO) on the small intestinal morphology and populations of enterobacteriaceae, lactobacilli and clostridia in ileal digesta and feces of weaned pigs. At 17 d of age, 36 pigs from nine litters were fitted with simple T-cannulae at the distal ileum and after a 2-h post-surgery recovery returned to their sows. At 21 d of age, the pigs were weaned and housed in individual metabolism crates. Pigs were allocated to receive a standard starter diet supplemented with or without 3000 mg kg–1 of ZnO. Ileal digesta and fecal samples were collected immediately before weaning and then on days 2, 4, 7, 9, and 11 after weaning and were used to quantify enterobacteriaceae, lactobacilli and clostridial populations by colony enumeration on selective media. Pigs were euthanized following the final sampling, and 2 cm sections of tissue were collected from sites 25, 50 and 75% along the length of the small intestine for determination of mucosal thickness (MT), crypt depth (CD), villous height (VH) and villous width (VW). Zinc oxide supplementation altered the mucosal morphology of the small intestine. Mucosal thickness (P < 0.08) and VH (P < 0.05) were increased at sites 25 and 50% along the length of the small intestine by ZnO supplementation. Overall VW also increased (P < 0.01) with ZnO supplementation. Crypt depth decreased (P < 0.05) at 75% along the length of the small intestine with ZnO supplementation. The ratio of VH to CD was higher (P < 0.05) for ZnO-supplemented than for control-fed pigs at sites 25, 50 and 75% along the length of the small intestine. There was no effect (P > 0.05) of supplementary ZnO on bacterial populations in ileal digesta or feces. The present study indicates that supplementing ZnO in starter diets changes the epithelial morphology of the small intestine, which may affect nutrient digestion and absorption in newly weaned pigs. Key words: Pigs, zinc oxide, bacteria, intestinal morphology
Effect of heat processing on nutrient digestibility in pea and supplementing amylase and xylanase to raw, extruded or micronized pea-based diets on performance of early-weaned pigs
Authors: Owusu-Asiedu A. , Baidoo S. K. , Nyachoti C. M.
Published: April 2011

Two experiments were conducted to investigate the effect of heat processing on nutrient digestibility and of both processing and exogenous feed enzymes on growth performance of 16-d-old weaned piglets fed pea-based diets. In exp. 1, 12 Cotswold pigs [4.5 ± 0.5 kg initial body weight (BW)] fitted with simple-T cannulae were used to determine apparent and standardized ileal amino acid (AA) digestibilities in raw, extruded, and micronized peas supplemented with amylase and xylanase. In exp. 2, 70 16-d-old weaned pigs were randomly assigned to a soybean-meal- (SBM)-based control and six pea-based diets during two consecutive periods (Phase 1, 4.5–10.0, Phase 2, 10.0–20.0 kg BW). The pea- (raw, extruded and micronized) based diets were fed with or without enzyme supplementation. Pigs were weighed weekly and feed intake was monitored daily. Blood samples were obtained from 10 pigs per treatment on days 0, 7 and 14 for plasma urea nitrogen (PUN) analysis. Heat processing improved (P < 0.05) apparent ileal digestibilities (AID) of most AAs, including lysine, methionine, threonine, and valine in extruded and micronized peas, but not raw peas. The AID was higher (P < 0.05) in enzyme-supplemented extruded and micronized peas than in raw peas. Micronization improved (P < 0.05) AID of lysine from 82 to 91%. The standardized ileal digestibilities (SID) of arginine, lysine, methionine and threonine were higher (P < 0.05) in extruded and micronized pea-based diets than in raw pea-based diets. Mean AID of indispensable AA was numerically improved (P < 0.08) from 79 to 88.0% following micronization. Feed efficiency was improved (P < 0.05) from 1.4 to 1.20 by supplementing raw pea-based diet with amylase and xylanase in phase 1. Supplementing raw pea-based diet with enzyme resulted in reduced (P < 0.05) PUN levels from 9.01 to 5.73 mg dL-1. The results demonstrate that compared to raw peas, extrusion and micronization improved AA digestibilities of amylase and xylanase supplemented pea-based diets and efficiency of feed utilization from 4.5 to 10.0 kg BW. However, feed intake and growth performance were not affected. Key words: Amylase, xylanase, early-weaned pig, amino acids, micronization, extrusion, digestibilities
Effects of delaying the LH surge and altering LH secretion on plasma hormones and embryo production in heifers superstimulated with FSH
Authors: Carrière P. D. , Kohram H. , Price C. A. , Durocher J. , Guilbault L. A.
Published: April 2011

Ovarian follicles were ablated by ultrasound-guided transvaginal aspiration in 20 Holstein heifers allocated to four groups (n = 5 per group). The first group (SOV) was superstimulated conventionally with FSH. In the other superstimulated groups, the LH surge was delayed by 24 h with progesterone (CIDR) and 100-μg injection of GnRH. The second group (CIDR-3.5d) received the CIDR on the second day of superstimulation. To increase LH pulsatility, the third group (CIDR-3.5d-GnRH-Pulsed) received repeated 5-μg injections of GnRH during superstimulation and the fourth group (CIDR-7d), received the CIDR with a first prostaglandin, 2 d prior to superstimulation. The number of corpora lutea (CL) and embryos was not significantly different (P > 0.1) in CIDR-3.5d compared to SOV (9.4 ± 2.0 vs. 13.8 ± 2.0 CL and 3.6 ± 1.2 vs. 5.8 ± 1.2 embryos, respectively). In the CIDR-3.5d-GnRH-Pulsed group, the 100-μg injection of GnRH failed to induce an LH surge and there were no CLs and no embryos recovered. In the CIDR-7d group, the number of CLs (5.6 ± 2.0, P < 0.05) and embryos (1.8 ± 1.2, P < 0.01) were reduced compared to SOV. In conclusion, a 24-h delay of the LH surge with a CIDR did not improve embryo production. In this delayed-surge model, increasing LH pulsatility prior to or during superstimulation resulted in a decrease in ovulation rate and embryo production. Key words: Superstimulation (FSH), GnRH, LH, CIDR, progesterone, oestradiol, embryo
The effects of feeding conjugated linoleic acid on pig liver vitamin A and retinol binding protein mRNA
Authors: Dugan M. E. R. , Rolland D. C. , Best D. R. , Meadus W. J.
Published: April 2011

Banni et al. (1999) indicated feeding conjugated linoleic acid (CLA) increases rat liver retinol and retinyl-ester levels. We wanted to determine if feeding CLA would affect pig vitamin A status. Feeding 0.5% CLA did not increase pig liver retinyl-palmitate but did increase retinol from 1.56 to 2.56 109g g-1 (P < 0.05) and the level of retinol binding protien mRNA relative to actin mRNA (P < 0.05). Key words: Conjugated linoleic acid, pig, vitamin A, retinol, retinol binding protein
The n-alkane profile of some native and cultivated forages in Canada
Authors: Boadi D. A. , Moshtaghi Nia S. A. , Wittenberg K. M. , McCaughey W. P.
Published: April 2011

Frage samples were collected from swards growing in Carberry, Manitoba, Brandon, Manitoba, Saskatoon, Saskatchewan, and St. John’s, Newfoundland, and the alkane concentrations were determined by gas chromatography. Considerable differences were observed in almost all odd-numbered alkanes and in their total content between species. The odd-numbered alkanes were always present in high concentrations compared to the even-chain alkanes in both native and cultivated species. Of the cultivated grasses, the fescues had very high concentrations of CN31 among the odd-chain alkanes, while the legumes tended to have higher concentrations of C29 than C31 or C33. The low concentrations of odd-chain alkanes (< 50 mg kg-1 DM) in little bluestem, indiangrass, reed canarygrass, orchardgrass, timothy and Russian wildrye forages could bias intake calculations of these forages when the double alkane technique is used. Differences between location and cultivar were observed for C29 in timothy and C31 in meadow bromegrass (P < 0.05). There were no effects of location and cultivar on n-alkane concentrations for orchardgrass (P > 0.05). Key words: n-alkanes, forage species, cultivar, location
Effect of temperament and behavioural reactions to the presence of a human during the pre-mating period on reproductive performance in farmed mink (Mustela vison)
Authors: Korhonen H. T. , Jauhiainen L. , Rekilä T.
Published: April 2011

The present study sought to evaluate the relationship between temperament, pre-mating behaviour and reproductive performance in farmed female mink (Mustela vison). Temperament was measured by using a stick test and behavioural reactions to the presence of a human during pre-mating period by a walking test. The experimental animals comprised 100 confident and 100 fearful scanblack female mink. In each temperament group, 58% of female mink were primiparous and 42% were multiparous. The length and timing of mating periods and the length of the gestation period were similar in all groups. Pooled data showed that the length of the gestation period correlated negatively with litter size (r = -0.17, P = 0.03). The whelping proportions for confident and fearful primiparous female mink were 81% and 74% (P = 0.37), respectively, and for multiparous females 83% and 81% (P = 0.78), respectively. The number of kits per mated and whelped female at parturition (P < 0.01 and P = 0.04, respectively) and at weaning (P < 0.01 and P = 0.07, respectively) was significantly higher in confident than in fearful females. A significant correlation between kit losses and litter size was found only in primiparous and multiparous confident females (r = 0.35, P = 0.02; r = 0.32, P = 0.07). Postnatal kit mortality was higher in primiparous confident females than fearful females. During walking tests, fearful animals, irrespective of age, remained in side the nest box more frequently than did confident ones. Stationary behaviour outside the cage (lying, sitting, standing, etc.) was more common in confident than in fearful animals (P < 0.001). Significant differences in locomotor activity or stereotypies were not found between the groups. In multiparous fearful females, the whelping result declined significantly with the increasing incidence of stereotypies (r = -0.37, P = 0.04). In primiparous fearful female mink, the relationship was the reverse (r = 0.37; P = 0.01). We conclude that the significant temperament dichotomy (confident vs. fearful) found in farmed mink stock has a marked effect on the reproductive performance of this species. Key words: Farm-bred mink, personality trait, temperament, reproductive performance, domestication
The digestibility and content of amino acids in toasted and non-toasted canola meals
Authors: Newkirk R. W. , Classen H. L. , Scott T. A. , Edney M. J.
Published: April 2011

A study was conducted to determine the level and digestibilities of amino acids and the level of glucosinolates in toasted and non-toasted canola meal samples produced in commercial crushing plants in western Canada. A total of 26 non-toasted and 31 toasted canola meals samples were analyzed for apparent ileal amino acid digestibilities using broiler chickens between 21 and 28 d of age. Commercially toasted canola meal contained 5.6 g 16 g-1 N (range 5.3–5.9) of Lys with a digestibility ranging from 65.5 to 85.7% (mean = 78.0%). Non-toasted canola meal contained 6.0 g 16 g-1 N (range 5.7–6.3) Lys with digestibility values ranging from 87 to 92% (mean = 89.7%). Toasted canola meal had an average total digestible amino acid content (not including Tyr and Trp) of 69.6 g 16 g-1 N (range 56.6–75.6) while non-toasted canola meal had 77.6 g 16 g-1 N (range 73.1–82.0). The levels of aliphatic glucosinolates in the toasted (6.16 μmol g-1 meal, range 1.2–12.5) and non-toasted meals (10.5 μmol g-1 meal, range 7.8–15.1) were low and likely of nonutritional consequence. In conclusion, non-toasted canola meal contains higher levels of digestible amino acids than conventional toasted canola meal and therefore consideration should be given to modifying commercial systems to produce a non-toasted meal. Key words: Canola meal, toasting, amino acid, digestibility, glucosinolates
Effects of synthetic conjugated linoleic acid (CLA) or bio-formed CLA as high CLA beef on rat growth and adipose tissue development
Authors: Mir P. S. , Okine E. K. , Goonewardene L. , He M. L. , Mir Z.
Published: April 2011

Two rat feeding experiments were conducted, concurrently, for 48 d, to determine the effects of feeding synthetic food-grade conjugated linoleic acid (CLA) containing 53% cis 9, trans 11 CLA and 44% trans 10, cis 12 CLA or bio-formed CLA as high CLA beef on adipose tissue development. In exp. 1, 30 (10/diet) weaned male Wistar rats (51 ± 0.65 g) were fed, ad libitum, a control diet, control with sufficient added synthetic CLA to achieve CLA concentrations of 1.1% of diet DM or the control, where the soybean oil in the diet was replaced with sunflower oil. In exp. 2, 20 (10/diet) weaned male Wistar rats (52.5 ± 2.5 g) were fed, ad libitum, diets in which freeze dried beef replaced the casein as the protein source. The meat in the two diets was derived either from steers raised without dietary oil or from beef from steers fed oil to increase CLA content by 144% from 3.36 to 8.20 mg g-1 lipid (high CLA beef). At the end of the experiment the rats were humanely sacrificed and the organs, muscles and the retro-peritoneal and inguinal fat pads were retrieved and weighed. A portion of the fat pad was processed for enumeration of adipocytes while a second portion was used for lipid extraction, and fatty acid composition was determined. In both experiments, diets fed to the rats did not affect rate of growth or carcass, muscle and organ (liver, heart and kidney) weights. In exp. 1, dietary synthetic CLA reduced (P < 0.01) the weight of the retro-peritoneal fat pad and this may have been related to a numerical (-9.8%) but non-significant reduction in feed intake. Although fat pad weight in rats fed sunflower oil was similar to that of rats fed the control diet, the adipocyte number was increased (P < 0.05) by 37%. Dietary supplementation with synthetic CLA, increased (P < 0.05) the CLA concentration in lipids from liver, inguinal fat and retroperitoneal fat of rats. In exp. 2, muscle, organ and fat pad weights were similar for the two meat treatments, but adipocyte number in both pads was lower (P< 0.05) in rats fed the high CLA beef by 40%, which may be a response to dietary CLA and/or a lower protein intake. The lipid from liver and fat tissues of rats fed CLA enhanced beef contained a higher (P < 0.05) CLA concentration than tissues from rats fed the control beef. Data suggest that dietary CLA from either synthetic or high CLA beef may decrease lipid storage potential in fat pads. Key words: Rat, adipose, development, conjugated linoleic acid, high CLA beef
Effects of feeding transgenic canola on apparent digestibility, growth performance and carcass characteristics of lambs
Authors: Stanford K. , Aalhus J. L. , Dugan M. E. R. , Wallins G. L. , Sharma R. , McAllister T. A.
Published: April 2011

This study evaluated the effects of including meal from glyphosate-tolerant (Roundup-Ready®) canola (RRC) in barley-based diets for lambs on apparent digestibility of the diets, growth performance of the lambs, and carcass quality and composition. Four isonitrogenous diets were prepared that included canola meal [6.5%, dry matter (DM) basis] from four different sources (two commercially available canola blends, COM1 and COM2; a transgenic line, RRC and the parental non-transgenic line from which RRC was derived, PAR). Apparent digestibilities of the four diets were determined using eight mature wethers (67.8 ± 2.3 kg) in a replicated Latin square with four 21-d periods. No aspect of digestibility (DM, fibre, or nitrogen balance) was influenced by canola source. The growth trial involved 60 early-weaned Arcott lambs (30 ewes; 30 wethers; initial age approximately 2 mo; initial weight 21.5 ± 1.0 kg). The lambs were blocked by weight and gender for assignment to treatments, and fed the diets until reaching or exceeding 45 kg body weight. Intake of DM was similar among lambs fed COM1, COM2 and PAR diets, and between PAR and RRC (COM1, COM2 > RRC, P < 0.05). Diet did not affect (P > 0.05) average daily gain or feed efficiency. Carcass yield grade was higher (P < 0.05) for COM1 and COM2 diets than for PAR or RRC, although carcass composition did not differ (P > 0.05) between PAR and RRC. Canola source did not affect (P > 0.05) meat tenderness, as determined by shear force, drip loss or intramuscular fat content. Meat colour o f RRC-fed lambs did not differ from that of all other treatment groups. In this study, including canola meal prepared from glyphosate-tolerant canola did not alter diet digestibility, feed efficiency, growth performance, carcass characteristics or meat quality of lambs. Key words: Growth, lambs, meat quality, ruminant, transgenic canola
Response of early weaned piglets to graded levels of dietary cobalamin
Authors: House J. D. , Fletcher C. M. T.
Published: April 2011

The water-soluble vitamin cobalamin plays a central role as a co-factor in key pathways of energy and protein metabolism. The dietary requirement of this vitamin for the young pig (5–10 kg) has been estimated at 17.5 μg kg-1, but it is derived from estimates made over 40 yr ago. In light of changes in swine production, including the selection for high lean potential genotypes and the move to earlier weaning times, a reassessment of the adequacy of current cobalamin estimates is warranted. To this end, two trials were conducted to test the following alternate hypothesis: The current National Research Council (NRC 1998) estimated cobalamin requirement for the 5- to 10-kg early-weaned piglet is inadequate to maintain optimal cobalamin status, as reflected by growth, feed conversion efficiency, plasma cobalamin and plasma homocysteine concentrations. In trial 1, 60 Cotswold pigs (17 ± 1 d, equal males and females) were randomly assigned to receive diets, formulated with ingredients essentially devoid of cobalamin, and containing either 0, 35, 70, 105, or 140 g crystalline cobalamin kg-1. After 15 d, growth, feed intake and feed conversion efficiency were not significantly different (P > 0.05) between the dietary cobalamin levels. However, plasma cobalamin was significantly lower (49.9 vs 186.7, 168.0, 164.7, and 178.7 pg mL-1; SEM 17.3; P < 0.05) and homocysteine was significantly higher (34.5 vs. 22.5, 26.0, 24.7, and 23.4 μmol L-1; SEM 2.9; P < 0.05) in piglets consuming diets containing 0 vs. 35, 70, 105 and 140 μg crystalline cobalamin kg-1, respectively. Trial 2 retained the same study design as trial 1, but added dietary cobalamin concentrations were equivalent to 0, 10, 20, 30, and 40 g kg-1. The observed pattern of responses in plasma cobalamin and homocysteine support a requirement of added cobalamin in excess of 30 μg kg-1 of diet. Taken together, the data support a requirement for the addition of 35 μg crystalline cobalamin kg-1 of a diet formulated with ingredients essentially devoid of natural cobalamin for the early-weaned piglet between 5 and 10 kg, a value that is double the current NRC requirement. In addition, the current study uses changes in the plasma concentration of the metabolite homocysteine as a novel approach for the estimation of the dietary requirement for cobalamin in animals. Key words: Cobalamin, early weaned pig, homocysteine, dietary requirement
Interaction of wheat micronization and cultivar on its feeding value for broilers
Authors: Niu Z. Y. , Classen H. L. , Scott T. A.
Published: April 2011

Three experiments were conducted to investigate the interaction between micronization and cultivar of wheat on grain chemical composition and feeding value for chickens. Micronized whole grain feeding was evaluated in one experiment using inclusion levels of 10 and 50% for starter and grower diets, respectively. Dietary enzyme was used in two other experiments to study its interaction with micronization and genotype of wheat. Wheat cultivars Genesis, Kyle, and Katepwa were micronized at 100°C for 50 s and incorporated into broiler diets. Micronization improved overall feed efficiency, but did not always increase body weight. When feeding whole grain to birds, micronization improved feed efficiency from 21 to 42 d and 0 to 42 d, but did not affect final body weight. Micronization of wheat cultivars reduced early growth rate of all birds, regardless of wheat form in the diets. Micronization did not impact AME and digesta viscosity. Cultivar Kyle had a higher dietary AME and a lower digesta viscosity, and resulted in feed efficiency and weight gain values superior to those of either Genesis or Katepwa (exps. 2 and 3). Enzyme increased weight gain, feed efficiency and dietary AME, and decreased digesta viscosity. Key words: wheat, cultivars, micronization, AME, broilers
Age of dam and age at measurement adjustments and genetic parameters for scrotal circumference of Canadian Hereford bulls
Authors: Crews Jr. D. H. , Porteous D. J.
Published: April 2011

The objective of the study was to estimate age of dam and age at measurement as adjustment factors for scrotal circumference in Canadian Hereford bulls (n = 9029) and to estimate genetic parameters for scrotal circumference, and birth and yearling weights. Quadratic effects of age at measurement and the interaction of age of dam with age at measurement were not important. Adjustment factors recommended for yearling bulls were 1.02, 0.33, 0.10, and 0.16 cm to adjust scrotal circumference of sons of 2-, 3-, 4-, and ≥ 10-yr-old cows to a mature dam (5 to 9 yr of age) equivalent. The linear partial regression coefficient for age at measurement was 0.036 cm d-1. Genetic parameters were estimated using a multiple trait animal model and REML. The heritability estimate for (age of dam and age at measurement) adjusted scrotal circumference was 0.40 ± 0.03, and heritability estimates were 0.43 ± 0.05, 0.21 ± 0.09, and 0.36 ± 0.03 for direct birth weight, maternal birth weight, and yearling weight, respectively. The genetic correlation of adjusted scrotal circumference with direct birth weight was low (0.15), and was moderate (0.38) with yearling weight, but was near zero (-0.01) with maternal birth weight. Environmental and phenotypic correlations of adjusted scrotal circumference were low with birth weight, and were high with yearling weight. These results indicate that there was a positive association between adjusted scrotal circumference and body weight. Genetic improvement of fertility through the use of adjusted scrotal circumference as an indicator trait would not be expected to be antagonistic to that for body weight. Key words: Beef cattle, fertility, Hereford, scrotal circumference
Copper and health status of cattle grazing high-molybdenum forage from a reclaimed mine tailing site
Authors: Gardner W. C. , Broersma K. , Popp J. D. , Mir Z. , Mir P. S. , Buckley W. T.
Published: April 2011

High concentrations (21–44 mg kg-1 dry matter) of Mo have been identified in forage in several reclaimed mining areas in British Columbia. Since Mo concentrations greater than 5 mg kg-1 in forage dry matter may result in molybdenosis because of a secondary Cu deficiency in ruminants, a study was undertaken to determine if cattle can safely graze the reclaimed land. For 12-wk grazing periods in 1994, 1995 and 1996, 32 cow/calf pairs grazed high-Mo forage at a reclaimed mine tailings site located at the Highland Valley Copper mine near Logan lake, BC. Half of the animals in the trial received a Cu supplement (All-Trace copper bolus) and the other half served as a control group. There were no significant differences (P < 0.05) in weight gain, liver Mo, serum Cu and Mo, and milk Cu and Mo between the two treatment groups of cows. Liver Cu was higher for the Cu bolus group at certain time periods in 1994 and 1995, indicating that the bolus was effective at supplying Cu. At all times, the liver Cu levels for the animals remained above the recommended critical level of 25 mg kg-1 dry matter. Animals appeared healthy and no signs of Cu deficiency were observed. Key words: Molybdenum, molybdenosis, copper, mine tailings, reclamation, animal health
Steer performance grazing hybrid bromegrass pastures
Authors: Thompson L. C. , Lardner H. A. , Cohen R. D. H. , Coulman B. E.
Published: April 2011

Producers in Saskatchewan require grazing information on new grass cultivars to improve production and quality of existing forage stands. Animal data are ultimately needed to validate the performance of these new varieties under grazed conditions. A 2-yr field experiment was conducted (2000–2001) to determine steer performance and species utilization when grazing crested wheatgrass (Agropyron pectiniforme R. & S.), smooth bromegrass (Bromus inermis Leyss.) and meadow bromegrass (Bromus riparius Rehm.) compared to hybrid bromegrass (Bromus riparius × Bromus inermis) pasture on an Orthic Black soil in east central Saskatchewan. Weight gain (kg d-1) was greater (P < 0.05) for steers grazing hybrid bromegrass pasture than crested wheatgrass pasture in the first year. However, in 2001, steers grazing crested wheatgrass pastures had greater (P < 0.05) average daily gain (ADG) than those grazing other pasture types. Total beef production (TBF) was greatest in both years (160 and 185 kg ha-1) from the hybrid bromegrass pastures. The greatest (P < 0.05) animal grazing days (AGD) were observed on hybrid bromegrass pastures. These results suggest that AC Knowles hybrid bromegrass is a suitable species for pasture use in Saskatchewan. Key words: Grazing, utilization, steer, grass pasture