bluuebunny/crossref_metadata_2025 huggingface dataset:
The relationship between creep feeding behavior of piglets and adaptation to weaning: Effect of diet quality
Authors: Fraser David , Pajor E. A. , Feddes J. J. R.
Published: March 2010

Individual variation in creep feed intake and its relation to adaptation to weaning were studied in piglets weaned at 4 wk of age. The animals received either a "low-complexity" creep-starter diet based on corn, barley and soybean meal (12 litters), or a "high-complexity", medicated, commercial diet without soybean meal (12 litters). Diets were fed as creep feed during the 2 wk before weaning, and as the sole diet during the 2 wk after weaning. Creep feeding behavior of piglets was monitored by video recording. Pigs fed the high-complexity diet consumed more creep feed (P < 0.05), tended to gain more during the week before weaning (P < 0.10), and converted feed more efficiently and gained more weight in the 2 wk after weaning (P < 0.01). Use of creep feed varied greatly among individual littermates. Multiple regression analysis showed that on the high-complexity diet, pigs that used creep feed more than their littermates tended to be those with low gains in weeks 1–3 after birth (P < 0.001), and tended to gain more weight during the week before and during the 2 wk after weaning (P < 0.01). The trends were consistent but weaker with the low-complexity diet. However, predictive power was low, with creep feeding accounting for only 4% of individual variation in post-weaning gain on the high-complexity diet and 1% on the low. Regardless of diet quality, therefore, creep feeding remained highly variable and only weakly related to weight gains during the 2 wk after weaning. Key words: Piglets, creep feed, weaning, feeding behavior
Comparaison de l'effet de deux analogues de la prostaglandine F2α sur la synchronisation de l'œstrus chez la vache de boucherie
Authors: Laverdière G. , Dufour J. J. , Roy G. L. , Lavoie D. , Proulx J.
Published: March 2010

The objective of this study was to compare the efficiency of cloprostenol and fenprostalene in synchronizing estrus. Before treatment, estrus was detected during 4.5 d for multiparous cows in exp. 1 (n = 105) and 7.5 d for primiparous and nulliparous females in exp. 2 (n = 86). Females that were not in estrus (exp. 1: n = 74 and exp. 2: n = 58) received at random, either 500 μg of cloprostenol (i.m.) or 1 mg of fenprostalene (s.c). Cattle synchronized with cloprostenol or fenprostalene that presented estrus within 5 d showed similar fertility rates (exp. 1: 86.1% vs. 88.0% and exp. 2: 89.3% vs. 72.2% for cloprostenol and fenprostalene, respectively) and PGF2α-estrus intervals (exp. 1: 68 h vs. 73 h and exp. 2: 57 h vs. 57 h). However, the incidence of synchronization (exp. 1: 97.3% vs. 67.6%, P < 0.001; and exp. 2: 93.3% vs. 64.3%, P < 0.01) and pregnancy rates (exp. 1: 83.8% vs. 59.5%, P < 0.05; and exp. 2: 83.3% vs. 46.4%, P < 0.01) were statistically higher for cloprostenol than for fenprostalene. In exp. 2, primiparous cows and heifers obtained similar reproductive performances. The fertility rate of cattle treated with cloprostenol in exp. 2 was higher than that of untreated cattle (89.3% vs. 50.0%, P < 0.001, n = 56). In exp. 1, the variance of interval to estrus was similar for both analogues, but in exp. 2, it was less variable after the administration of cloprostenol (P < 0.05). Intervals between cloprostenol injection and estrus (0–10 and 0–15 d) were shorter (P < 0.05) and less variable (P < 0.001) than fenprostalene–estrus intervals. These results indicate that cloprostenol has a better potential for estrus synchronization than fenprostalene. Key words: Cloprostenol, fenprostalene, estrus synchronization, prostaglandin F2α, beef cattle
Cryopreservation alters the Ca2+ flux of bovine spermatozoa
Authors: Bailey J. L. , Buhr M. M.
Published: March 2010

Capacitation and the acrosome reaction are Ca2+-dependent events that must be properly timed for successful fertilization to occur. To test the hypothesis that the cryopreservation procedures alter the ability of bovine spermatozoa to regulate Ca2+, the ability of Percoll-washed fresh and cryopreserved spermatozoa obtained from the same ejaculate (four ejaculates from each of six bulls) to regulate Ca2+ over time was monitored using the fluorescent Ca2+ chelator indo-1. The ability of spermatozoa to control Ca2+ levels varied among ejaculates from a bull, and among bulls; these effects were statistically accounted for in the analysis of the effects of cryopreservation. Initially, cryopreserved spermatozoa had lower viability, motility, and normal acrosome scores and more intra- and extra-cellular Ca2+ than fresh spermatozoa. Intra- and extra-cellular Ca2+ was monitored for 150 min, with 1 mM exogenous Ca2+ or buffer being added at 30 min to the spermatozoa being used to monitor intracellular Ca2+. By 30 min, extracellular Ca2+ was higher for fresh cells and then remained constant. Intracellular Ca2+ of fresh and cryopreserved spermatozoa in Ca2+-free media slowly increased. While both fresh and cryopreserved cells in Ca2+-supplemented media accumulated Ca2+ more rapidly, cryopreserved spermatozoa did so faster than fresh. Post-experimental viability was lower in cryopreserved spermatozoa that had been exposed to exogenous Ca2+. In conclusion, cryopreservation affects initial intra- and extra-cellular Ca2+ levels of bovine spermatozoa, and their ability to control subsequent rates of Ca2+ accumulation. Key words: Bovine, cryopreservation, calcium, indo–1, spermatozoa
Relationships among in vivo fertility, computer-analysed motility and in vitro Ca2+ flux in bovine spermatozoa
Authors: Bailey J. L. , Buhr M. M. , Robertson L.
Published: March 2010

Correlations among computer-assisted spermatozoa motility analyses, Ca2+ fluxes and in vivo fertility of bovine spermatozoa based on a total of 4482 inseminations were investigated in each of four ejaculates from six bulls. The Ca2+ parameters assessed the rate of change in intra- and extracellular Ca + in fresh and cryopreserved spermatozoa from the same ejaculates and were described in another study. Of the seven motility parameters of cryopreserved semen investigated, all differed significantly among bulls but none were related to the in vivo fertility of cryopreserved semen. The amplitude of lateral head displacement, a motility parameter associated with hyperactivation, was positively correlated with the intracellular Ca2+ levels and the rate of Ca2+ accumulation of cyropreserved spermatozoa. The highest fertility was observed when initial extracellular Ca2+ for cryopreserved spermatozoa was high and when Ca2+ efflux rates of cryopreserved cells approached the higher efflux rates of fresh spermatozoa. Fertility was reduced when cryopreserved spermatozoa had initial internal Ca2+ levels greater than those of fresh spermatozoa or when cryopreserved spermatozoa internalized Ca2+ rapidly. Calcium flux, but not motility, may predict fertilizing capacity of cryopreserved bovine spermatozoa. Key words: Calcium, computer-analysed motility, fertility, spermatozoa, bull
Roasted, steeped soybeans for growing steers fed alfalfa–grass silage
Authors: Mosimanyana B. M. , Mowat D. N.
Published: March 2010

A 56-d growth trial was conducted to evaluate performance and plasma amino acid (AA) responses of 63 Charolais-crossed steer calves fed alfalfa–grass silage diets. The basal diet was supplemented with either high-moisture corn (control), roasted, flaked, steeped (1 h) soybeans or a 60:40 (dry basis) mixture of corn gluten and blood meal (CG–BM). All diets were balanced for net energy, while the steeped soybeans and CG–BM diets were balanced for rumen-undegradable protein (RUP). Dry matter intake was similar across diets (2.39% of BW). Weight gains were higher (P < 0.01) for the steers fed with CG–BM (12.6%) and soybean (6.9%) supplemented rations than control steers. Digestibilities of neutral and acid detergent fibre were not adversely affected by roasted, steeped soybeans. Plasma glucose was lower (P < 0.05) and plasma urea was higher (P < 0.05) in the soybean- and CG–BM-supplemented steers than in control steers. Supplementation with steeped soybeans or CG–BM increased (P < 0.001) total plasma essential AA, branched-chain AA (BCAA) and BCAA/glycine ratio and lowered the total nonessential AA (NEAA) to essential AA (EAA) ratio. Plasma AA parameters were directly related to the rumen undegradability of the protein supplements. A lower plasma NEAA/EAA ratio indicated improved protein nutrition. These results showed that roasted, steeped soybeans delivered needed protein to the small intestine of rapidly growing steers fed alfalfa–grass silage. Key words: Roasting, steeped, soybeans, protein
Apparent absorption and retention of nutrients during the postweaning period in sows fed supplemental fat or lysine
Authors: Grandhi R. R.
Published: March 2010

A total of 36 first-parity Landrace × Yorkshire sows and 17 second-parity Yorkshire sows were used in separate metabolism trials of a 2 × 3 factorial design with two lactation (21–d) weight-loss groups and three postweaning treatment diets to determine the effect of feeding supplemental fat or lysine on apparent absorption and retention of nutrients during the postweaning period. Following a 5-wk lactation, sows were housed in individual sow metabolism stalls equipped for separate collection of feces and urine. The three treatment diets fed during the postweaning period were (1) control — a barley – canola meal gestation diet (12.4 MJ DE, 4.7 g lysine kg−1, and 12% protein) fed 2 kg d−1, (2) fat — the control diet plus animal fat premix to provide approximately 50% more DE d−1, and (3) lysine — the control diet with supplemental lysine to provide approximately 50% more lysine d−1. Feeding supplemental fat increased (P < 0.05) fat absorption and energy retention in sows of both parities. Water intake and absorption were reduced by feeding supplemental fat in first-parity sows. Feeding supplemental lysine increased nitrogen absorption in first-parity sows. The absorption and retention of both Ca and P were also higher in first-parity sows fed supplemental fat or lysine. The results indicated that feeding supplemental fat or lysine during the postweaning period may improve the absorption and retention of certain nutrients in sows. Key words: Postweaning, sows, nutrients, absorption, retention
Performance of laying hens as affected by the supplementation of a barley-based diet with a crude enzyme preparation from Trichoderma viride
Authors: Brufau J. , Cos R. , Pérez-Vendrell A. , Esteve-Garcia E.
Published: March 2010

Two experiments were conducted to compare the performance of Leghorn hens fed a barley-based diet (68.93%) containing three levels of a Trichoderma viride enzyme supplement (0, 100 and 200 mg kg−1 as treatments T2, T3 and T4, respectively) with those obtained when fed a corn-based diet (Treatment T1). In exp. 1, 80 hens were used to determine performance during four 28-d periods, between 21 and 37 wk of age. Egg production, feed consumption, feed efficiency and egg weight of the hens were not affected by enzyme supplement and were similar to those of hens fed the corn diet (P > 0.05). There were also no significant effects on feed consumption per gram of egg or per bird per day (P > 0.05). There was a significant interaction for egg weight between enzyme addition and periods (P < 0.034), indicating that enzyme supplementation improved egg size in the early periods. In exp. 2, 20 hens were fed the same diets to measure water consumption and the ratio of water to feed consumption. Water consumption was not affected (P < 0.07) but the ratio of water to feed was significantly reduced (P < 0.0005) when enzyme was added to the barley-based diet. Water consumption in g d−1 was 172 for T1, 215 for T2, 211 for T3, and 195 for T4, and the water to feed ratios were 1.40, 1.85, 1.66, and 1.56, respectively. These results demonstrate that barley can replace corn in layer diets and that the addition of enzyme to barley-based diets appears to improve egg size and to reduce water consumption relative to feed intake in young laying hens. Key words: Laying hens, performance, water consumption, β-glucans, enzyme supplementation
A review of bovine growth hormone
Authors: Burton Jeanne L. , McBride Brian W. , Block Elliot , Glimm David R. , Kennelly John J.
Published: March 2010

Unprecedented numbers of technical papers, abstracts, and short communications have been published in the past decade regarding the effects of exogenous bovine growth hormone on milk production, health, and reproductive efficiency of treated dairy cows. In well-managed dairy herds, exogenous growth hormone increases milk production without altering normal variability in milk composition. This has held true regardless of dairy breed tested, geographical location studied, or feeding management system used. Also consistent across studies is the rapidity of the galactopoietic effect of administered bovine growth hormone, which arises from altered partitioning and use of post-absorptive nutrients and increased synthetic capacity of the mammary gland. Growth hormone and its associated peptide, insulin-like growth factor-I, are now known to provide chronic lipolytic, diabetogenic, and gluconeogenic signals to target tissues culminating in increased mammary gland availability of glucose and nonesterified fatty acids. Together with yet ill-defined effects on mammary secretory tissue, this homeorhetic control of metabolism elicited by exogenous growth hormone is so efficient that treated cows are not more susceptible to metabolic disorders than untreated cows. However, some studies have reported an increased frequency of mastitis in groups of treated cows. This has been attributed mainly to increased milk volume in the mammary glands of treated cows and no convincing data are available that show decreased mammary gland immunity as a result of growth hormone treatments. On the contrary, an expanding body of evidence implicates growth hormone as a key neuroendocrine factor that is required for immunological competence. Trends of decreased reproductive efficiency in cows treated with growth hormone have also been reported, but available data imply that this is probably an indirect effect via prolonged negative energy balance in cows treated in early lactation rather than a direct negative effect on estrous cycling via altered reproductive hormone profiles. The objectives of the present review are to bring into focus and summarize pertinent biological discoveries regarding the treatment of dairy cows with recombinant bovine growth hormone, and to explore areas where additional growth hormone research is needed or warranted. Key words: Growth hormone, somatotropin, dairy cows, insulin-like growth factor-I
Effects of a growth implant and age of dam on growth and fertility in heifer calves
Authors: Rutter L. M. , Day P. A.
Published: March 2010

A field trial was conducted to determine the effects of a growth implant on growth, pregnancy rate, calving difficulty and calf weaning weight in replacement beef heifers. Heifers were assigned equally to either a control (n = 43; no implant), Ralgro (n = 43) or Synovex-C (n = 42) treatment group based on age of dam and age and weight at the start of the trial (implantation at 45–90 d of age). Neither Ralgro nor Synovex-C enhanced heifer weight or average daily gain (ADG) from the start of the trial to weaning (approximately 7 mo of age), breeding, or pregnancy determination. At breeding, Synovex-C implanted heifers had greater pelvic area than controls while Ralgro implanted heifers were intermediate (control = 149.7, Ralgro = 154.7 and Synovex-C = 157.4 pooled SE of 2.2 cm2; P = 0.05). Pelvic dimensions were similar among treatments at pregnancy determination and there were no treatment effects on calving difficulty. Age of dam affected heifer weight (P = 0.0005) and ADG (P = 0.001) to weaning, with heifers from mature cows weighing more at weaning and having a higher ADG from the start of the study to weaning than heifers from either first- or second-calf cows. Post-weaning performance of heifers from first-calf cows was similar to heifers from mature cows while heifers from second-calf cows were lighter at breeding (P = 0.04) and had a lower ADG from weaning to breeding (P = 0.04). Age of dam did not influence pregnancy rate (P = 0.10), but more heifers from second-calf cows calved late in the calving season (≥ 64 d) compared with heifers from either first-calf or mature cows (P = 0.04). It appears from this field trial that use of a growth implant between 45 and 90 d of age neither enhanced growth nor impaired fertility in beef heifers bred as yearlings. It also appears that second-calf 3-yr-olds may need to be managed separately from the mature cow herd in order to optimize replacement heifer development. Key words: Bovine, replacement heifers, growth implant, age of dam, weight, pregnancy rate
Milk yield and composition in first-cross and backcross beef cows
Authors: McKay R. M. , Rahnefeld G. W. , Weiss G. M. , Fredeen H. T. , Newman J. A. , Lawson J. E. , Bailey D. R. C.
Published: March 2010

Milk yield and composition from three distinct milkings (spring, August, and fall) were evaluated on first-cross and backcross cows maintained under two contrasting environments. The dam crosses at Brandon (semi-intensive cultivated pasture management) were HA, SN, CN, ACA, CCA, ASA, SSA, HCH, CCH, HSH, SSH, NCN, CCN, NSN, and SSN with H = Hereford, A = Angus, N = Shorthorn, C = Charolais, S = Simmental and a SSA cross was 3/4 Simmental-1/4 Angus. At Manyberries (semi-arid and short grass rangeland) the dam crosses were HA, SN, ASA, SSA, HSH SSH, NSN, and SSN. All cows were bred to Limousin bulls and milkings took place from 1981 to 1985, inclusive. Definitive differences among the backcrosses and between the backcrosses and the F1 crosses were not present. Possible genotupe × environment interactins were observed for milk yield and composition. Milk yield and composition were affected by age of cow and influenced cow and calf weight changes. Key words: Beef cattle, crossbreeding, backcrosses, milk yield, milk composition
Developmental appearance of peptide-binding sites in the small intestine of the neonatal piglet
Authors: Tyler H. D. , Croom Jr. W. J. , Vigna S. R. , McVey D. C.
Published: March 2010

The ontogeny of the expression of specific binding sites for bombesin (BBS), vasoactive intestinal polypeptide (VIP), and gastrin in the neonatal pig was examined. Piglets were sacrificed at birth, 1 d, 1 wk, 3 wk and 4 wk, and samples of duodenal, jejunal and ileal tissue were harvested for autoradiographic analysis of saturable radioligand binding. Monoiodinated, biologically active 125I-Tyr4-BBS, VIP or gastrin (100 pM) was applied to slide-mounted sections of piglet intestinal tissue and localized using autoradiographic analysis of radioligand binding. Saturable binding sites for 125I-BBS first appeared in duodenal tissue of 7-d-old piglets, with evidence for continued presence in this tissue through 21 d. BBS binding sites were localized in duodenal mucosa, with no detectable binding in any other tissue layers. No evidence for saturable binding of 125I-Tyr4-BBS was found in intestinal sections from either newborn, 1-d-old or 4-wk-old piglets. Saturable binding sites for 125I-VIP were present in duodenal, jejunal and ileal tissues of piglets at all ages studied and were present in both the mucosa and the muscularis externa. No saturable binding sites for 125I-gastrin were observed in intestinal sections from piglets at any of the ages studied. These results suggest potential sites of direct action of VIP in newborn, suckling and newly weaned piglets. Bombesin, however, may have direct actions only on the duodenal mucosa at 7–21 d of age. Key words: Bombesin, vasoactive intestinal polypeptide, gastrin, piglet, small intestine, newborn
Supplemental chromium and bovine respiratory disease vaccines for stressed feeder calves
Authors: Wright A. J. , Mowat D. N. , Mallard B. A.
Published: March 2010

Performance, morbidity, serum Cortisol, plasma ascorbate (AsA) and serum tri-iodothyronine (T3) were evaluated in crossbred steer calves purchased at sales in Ontario. Thirty-three steers were randomly assigned to each of control; vaccination with Infectious Bovine Rhinotracheitis, Parainfluenza-3, Bovine Viral Diarrhea, and Bovine Respiratory Synctial Virus vaccine and P. haemolytica vaccine; 0.14 ppm supplemental chelated Cr; and Cr plus vaccines, for the 49 d trial. Supplemental Cr plus vaccine increased (P < 0.05) daily gain and feed intake during the first 28 d. Furthermore, vaccination increased (P < 0.05) 28 d gain for mid-performing steers. Vaccines, Cr and Cr plus vaccines did not reduce morbidity (P > 0.05); however, the Cr-supplemented group had fewer relapses (P < 0.05). Rectal temperature was reduced in both vaccinated and Cr-supplemented calves on days 10–16 post-arrival. Serum cortisol was reduced (P < 0.05) in vaccinated calves and morbid Cr-supplemented calves on day 28 post-arrival. The ratio of free to total T3 on day 7 and day 14 post-arrival, and AsA on day 14 post-arrival was greater (P < 0.05) for calves receiving supplemental Cr plus vaccines. Results confirm previous reports of the beneficial effect of Cr on performance, and indicate some additive effects of Cr and vaccines with respect to daily gain and plasma ascorbate. Key words: Chromium, vaccines, ascorbic acid, tri-iodothyronine, stress, calves
Seasonal variation in intake and digestion of a high-roughage diet by muskoxen
Authors: Adamczewski J. Z. , Flood P. F. , Chaplin R. K. , Schaefer J. A.
Published: March 2010

We studied changes in body weight, intake, retention time and apparent digestibility of a supplemented brome-alfalfa hay by mature muskoxen held near Saskatoon, Saskatchewan during two seasonal cycles. Body weights and voluntary intake were monitored during 16 trials from late March 1990 to December 1991, in four annually breeding females and in three hysterectomized females. Retention time of the hay and apparent digestibility of the diet were estimated in winter and summer 1991 from fecal excretion of chromium (Cr) after a pulse dose of Cr-mordanted hay, and from forage/fecal concentrations of chromic oxide, respectively, in six non-breeding muskoxen. Mean (±SE) body weights of breeding females were greatest in February and March (248 ± 5 kg) and lowest following calving in late May or early June (216 ± 6 kg), while mean weight of hysterectomized females declined little from a peak of 228 ± 21 kg in February-March to a low of 213 ± 21 kg in July. Mean dry matter intake of breeding females was highest in July and August (62 ± 3.6 g d−1 kg−0.75) then declined slowly to its lowest point in March and April (41 ± 0.7 g d−1 kg−0.75). Dry matter intake of hysterectomized cows was less clearly seasonal but averaged 42 ± 1.7 g d−1 kg−0.75 in late winter and 50 ± 4.9 g d−1 kg−0.75 in mid-summer. Mean retention time of hay, calculated using a noncompartmental model, declined significantly from 114 ± 4 h in March to 95 ± 4 h in July. Apparent organic matter digestibility decreased significantly from 73.8 ± 0.8% in winter to 61.7 ± 1.3% in summer. Compared with other ruminants, muskoxen are grazers exceptionally well-suited to digesting graminoid forage, with relatively low maintenance requirements and prolonged retention times. Most of the seasonal changes in weight and intake of breeding females could be ascribed to reproductive cost, but there also appeared to be seasonal effects on intake, retention time and body weight in non-breeding muskoxen. Key words: Digestibility, intake, maintenance requirements, muskoxen, retention time, seasonal variation
An investigation of the feasibility of predicting nitrogen-corrected true metabolizable energy (TMEn) content in barley from chemical composition and physical characteristics
Authors: Zhang W. J. , Campbell L. D. , Stothers S. C.
Published: March 2010

A study utilizing 91 barley samples was conducted to investigate the feasibility of predicting the nitrogen-corrected true metabolizable energy (TMEn) value of barley for poultry. The samples included three barley types (six-row malting and feed and two-row feed) that were grown at 12 different locations in Manitoba from 1986 to 1988. Substantial variation in chemical and physical measurements was evident among the barley samples studied, and data indicated TMEn of 13.10–14.59 with a mean of 13.97 (MJ kg−1 on dry matter). It was found that TMEn was negatively correlated with neutral detergent fibre (NDF) level (r = −0.784) and positively correlated with test weight (r = 0.627). Significant relationships also existed between TMEn and contents of starch and fat, but only 7–8% of the variation in TMEn was accounted for by those variables. Inclusion of NDF, gross energy (GE), fat, protein and starch terms in a multiple-regression equation resulted in a slight decrease in residual standard deviation and an increase in R2. The best combinations of predictor variables were, in decreasing order, NDF, GE and fat selected from stepwise regression and NDF, fat and starch selected from the Mallows Cp values. With the exception of the equation using test weight as sole predictor, the errors estimated from the simple- (NDF as sole predictor), multiple- and stepwise-regression equations or the equation selected according to the Mallows Cp value were similar to the error approached for the biological measure, TMEn. Key words: Rooster, barley, nitrogen-corrected true metabolizable energy, prediction
Effects of feeding diets containing Fusarium (naturally) contaminated wheat or pure deoxynivalenol (DON) in growing pigs
Authors: Trenholm H. L. , Thompson B. K. , Foster B. C. , Charmley L. L. , Hartin K. E. , Coppock R. W. , Albassam M. A.
Published: March 2010

Three experiments were conducted to determine the effects of feeding diets containing laboratory synthesized deoxynivalenol (DON), or Fusarium (naturally) contaminated wheat containing DON on performance and health of young pigs (32.8–41.1 kg body weight). Diets containing 3.4–19.1 mg DON kg−1 were fed to pigs ad libitum for 14 d (exps. 1 and 2) or 7 wk (exp. 3) after which time each pig was slaughtered and blood, tissue and organ samples taken for analysis. All pigs responded to DON-contaminated diets with an immediate reduction in feed intake and body weight gain followed by some degree of recovery that was dependent on the dietary DON concentration. Negative linear relationships were found between feed intake or body weight gain and dietary DON concentration with pure DON and naturally contaminated wheat diets. Feed intake and weight gain were, respectively, 18 and 23% lower when a diet containing naturally contaminated wheat was fed compared to a diet containing an equivalent concentration of pure DON. Effects of DON on organ weights, relative to body weight, were inconsistent among experiments. The gastric mucosa was thinner and more eroded and had a higher degree of folding in the esophageal region in most groups fed DON-contaminated diets compared to those fed the control diet. Effects of DON on the fundic and cardiac regions of the stomach were inconsistent among treatments and experiments. There was little or no effect of DON on most of the blood parameters measured. Key words: Pure deoxynivalenol, naturally contaminated wheat, swine, intake, gain, vomitoxin, mycotoxin, fusarium, trichothecene
Calving and weaning performance of calves from heifers bred to easy calving sires
Authors: Tong A. K. W. , Vincent B. C. , Newman J. A. , Jones S. D. M. , Price M. A.
Published: March 2010

In a calving ease comparison involving 106 calves born to first calf heifers, calves sired by Red Angus bulls were heavier at birth and required more calving assistance than Corriente-sired calves. However, the easier calving Corriente-sired calves experienced equivalent death loss and were significantly lighter at 3, 5 and 7 mo of age. Key words: Beef, ease of calving, birth weight, weaning weight, Red Angus, Corriente
Genetic parameter estimates of conformation and performance traits in station-tested Limousin bulls
Authors: Miglior Filippo , Burnside E. B. , Kemp R. A.
Published: March 2010

Genetic and residual parameters were computed for conformation and performance traits of Limousin bulls in Ontario central test stations. Following editing, data were available on 456 bulls tested in 1990. Genetic parameters for performance traits were similar to those reported in the literature. Heritability of bone score (1 — light to 9 — heavy) was 0.22 ± 0.23. Heritability of a composite muscular development score was 0.51 ± 0.14. Muscular development was positively correlated genetically with all traits studied, including average daily gain (140 d), height, scrotal circumference and bone, and very highly correlated genetically with backfat thickness and weight at end of test. Selection for muscular development using a linear scoring system is feasible, but consideration should be given to correlated responses in other economically important traits. Key words: Multiple-trait analysis, growth and type traits correlations, station-tested beef bulls
The effect of daily injections of prolonged-release implants of recombinant porcine somatotropin on behaviour in market-weight pigs
Authors: Schaefer A. L. , Jones S. D. M. , Tong A. K. W. , Passillé A. M. B. De , Rushen J.
Published: March 2010

Animal behaviour frequency data were collected on 92 ad libitum fed Yorkshire pigs (96 kg) allocated to one of three recominant porcine somatotropin (rpST) treatment groups (36 prolonged-release rpST implants at 2 mg d−1 pig−1, 40 daily injection rpST pigs at 2 mg d−1, and 16 control or sham-injected pigs). From time-lapse recordings of animal behaviour, ethogram analysis revealed that of the 10 behaviours studied, investigative behaviour, was the only trait affected by rpST treatment, with the daily injected pigs showing a slightly lowered percentage of time (P < 0.05) spent investigating their pen (7.3% d−1 vs. 13.6% d−1 in control and 10.1% d−1 in prolonged-release treatment group). Key words: Behaviour, porcine somatotropin, pigs
Evaluation of the lean meat colour of commercial pigs produced in Quebec
Authors: Hammell K. L. , Laforest J. P. , Dufour J. J.
Published: March 2010

Data from a total of approximately 2900 commercial pigs tested in 12 trials from 1987 to 1990 at the Beaumont test station in Quebec were used to determine the effect of sex, sire breed, cross type and parity number of the dam on meat colour. Pigs were housed four to a pen and fed commercial diets. Meat colour measurements were taken 24 h or 72 h after slaughter in a commercial abattoir. The sex of the pigs had no major effect on any of the meat colour measurements. Commercial pigs sired by Hampshire or Hampshire-Duroc boars had characteristics of the loin and ham associated with a paler meat (lower ultimate pH and a higher Luminosity L*) than pigs sired by Landrace, Yorkshire or Duroc boars. A Chi-square analysis of the data indicates that the meat from pigs sired by Hampshire or Hampshire-Duroc boars was more often classified within the colour standards 1 and 2, and less often classified within the colour standards 4 and 5 than the meat from pigs sired by Landrace, Yorkshire or Duroc boars. Four-way cross and especially synthetic cross pigs had a paler meat than single cross, backcross and three-way cross pigs. Overall, less than 3% and less than 1% of the pigs produced meat with a colour standard of 1 (extremely pale) or 5 (extremely dark), respectively. Parity number of the dam did not affect meat colour. A factor analysis and Pearson's coefficients of correlation between the meat colour characteristics indicate that taking the same measurements on both the loin and ham muscle add relatively little information on meat colour. It appears that measuring the pH, the luminosity L* and the chromaticity value a* on either the loin or the ham muscle could be sufficient for an acceptable estimation of meat colour of commercial pigs from the present study. Key words: Pig, meat colour, pH
Effect of level of dietary potassium on the absorption and excretion of calcium and magnesium by lactating cows
Authors: Fisher L. J. , Dinn N. , Tait R. M. , Shelford J. A.
Published: March 2010

This study was undertaken with the objective of providing more basic information on the absorption and excretion of calcium (Ca) and magnesium (Mg) by lactating cows when high levels of potassium (K) are fed. Employing potassium carbonate as the source of supplemental K, total mixed rations were formulated to contain 1.6 (low), 3.1 (medium) and 4.6% (high) K. The three rations were fed to 15 Holstein cows in mid-lactation in a 3 × 3 Latin square experiment replicated five times. The experimental periods were 21 d in length. Blood, rumen and milk samples were obtained during the 2nd and 3rd wk of each experimental period and two cows from each treatment group were subjected to total collection procedures for feces and urine during the last 4 d of each experimental period. Dry matter intake was 23.0, 23.8 and 22.3 kg d−1 for the cows fed the low, medium and high K diets, respectively. Milk yield was lower (P < 0.05) for cows fed the high compared to the low and medium K diets. Level of K in the diet did not influence the fat and protein content of the milk but Ca content was lower (P < 0.05) for cows fed the medium and high K diets compared with those fed the low K diet. Plasma K levels were 15.0, 15.7 and 16.2 mg dL−1 while plasma Mg levels were 2.35a, 2.25ab and 2.17b mg dL−1 for cows on the low, medium and high K diets, respectively. The acetate to propionate ratio in the rumen fluid was wider (P < 0.05) for the cows fed the medium and high K diets compared with those fed the low K diet. The apparent absorption of Mg but not Ca was reduced with increasing levels of K in the diet. Both water consumption and urine output were greater (P < 0.05) for the cows fed the medium and high K diet compared with those fed the low K diet. The concentration of Ca and Mg in the urine dropped markedly and total excretion of Ca and Mg was lower (P < 0.05) for cows fed the medium and high K diets compared with those fed the low K diet. It was concluded from the results of this study that high K levels in the diet interfere with absorption of Mg but not Ca. However, K did appear to interfere with the utilization of Ca as indicated by the lower amount of Ca in the milk and urine. Increasing K levels in the diet increased water consumption and urine output which has major implications for waste management. Key words: Lactating cows, excess potassium, calcium, magnesium
Effect of 2-row or 6-row barley and a commercial enzyme preparation on growing-finishing broiler chickens from 3 to 6 weeks of age
Authors: MacLean J. , Webster A. B. , Anderson D. M.
Published: March 2010

A study was conducted to determine the efficacy of barley-based diets with or without a crude enzyme preparation for male broiler chickens from 3 to 6 wk of age. Treatments consisted of feeding grower and finisher diets based on two locally grown cultivars of barley, 2-row (unspecified cultivar) and 6-row (Leger) added at 0, 20, 40 and 60%, with 0 or 1000 mg commercial enzyme preparation/kg diet. The starter diet contained no barley. Enzyme addition to the 2-row barley-based diets resulted in significantly heavier 6 wk body weights compared to the non-supplemented diets and significantly improved feed efficiencies during the 5- to 6-wk period indicating an enzyme response in older birds. Level of 2-row barley did not have significant main effects on 6 wk body weight, weight gain, feed consumption, feed efficiency, mortality, or live grade, except for leg abnormalities. A significant linear contrast revealed increased percentage of leg abnormalities as the level of barley in the diet increased. Significant interactions were found between level of 2-row barley and enzyme addition for feed consumption and feed efficiency from 3 to 5 wk of age. Significant quadratic contrasts for level of barley within non-supplemented treatments indicated lower feed consumption of the 20 and 40% barley-fed birds than the 0 and 60% barley-fed birds during the 3-to 5-wk period. During the 5- to 6-wk period, feed consumption of the enzyme-supplemented diets increased linearly with percentage of barley in the ration. Neither level of 6-row barley nor enzyme addition to the 6-row barley diets had significant main effects on 6 wk body weight, weight gain, feed consumption, feed efficiency, or live grade. Significant interactions were found between level of 6-row barley and enzyme addition for 6 wk body weight, 3–6 wk weight gain and feed consumption for the 5–6 wk period. A significant quadratic contrast for level of barley within non-supplemented treatments revealed lower feed consumption of the 20 and 40% barley-fed birds compared to the 0 and 60% barley-fed birds during the 5–6 wk period. Thus, for the diets without glucanase, there was an effect of barley percentage which became apparent at different ages depending on the barley cultivar. As with the 2-row barley diets, there was a significant linear increase in feed consumption of the enzyme-supplemented diets as the level of 6-row barley in the diet increased during the 5–6 wk period. It appears from the results that the grower and finisher diets could contain up to 60% barley without being detrimental to growth but incidence of mortality or leg abnormality may increase somewhat. Enzyme addition improved feed efficiency for the 2-row barley diets, and erased the quadratic effects of barley level apparent when diets did not include β-glucanase. Key words: Barley, broiler chicken, enzyme, growth
Performance, carcass and pork characteristics of castrates and gilts self-fed diets differing in protein content and lysine:energy ratio
Authors: Castell A. G. , Cliplef R. L. , Poste-Flynn L. M. , Butler G.
Published: March 2010

The effects of five diets, with 12–18% crude protein (CP) and 6.6–10.8 g lysine per MJ digestible energy (DE), on live performance, carcass and meat quality criteria were recorded for 90 pigs in a split-plot design involving male castrates and gilts and three replicates, with three pigs per pen. The five diets, differing in the ratio of barley:soybean meal, were fed as pellets, ad libitum from 25 to 98 kg liveweight. A balanced incomplete block design was used with four additional pens to assess the palatability of the diets offered in pairs sequentially over 10 wk. As expected, castrates had a higher intake (2817 vs. 2580 g d−1) and daily gain (888 vs. 800 g d−1) than gilts and were relatively fatter except when fed the lowest CP diet. While an increase in dietary CP, or lysine:energy ratio, led to significant improvements in growth rate, gain:feed and lean content, there was a concomitant reduction in marbling and sensory appeal. The palatability study suggested that both castrates and gilts tended to favour the intermediate diets (8.8 and 10.1 g lysine per MJ DE) over the others, with a preference for higher CP diets in the early growth period. Estimates of the lysine:DE ratio for maximum live performance indicated that gilts should receive > 10.8 in the pre- − 50 kg period and approximately 10.1 g lysine per MJ DE thereafter. For castrates, the respective ratios were 10.8 and 8.8 g per MJ DE. Split-sex feeding, with gilts receiving about 2% higher dietary protein levels than castrates, was also favoured by the estimates of economic benefits for the producer. Key words: Pigs, lysine, digestible energy, carcass, pork quality
45Calcium dynamics of hens laying thick- or thin-shelled eggs
Authors: Clunies Martin , Leeson Steve
Published: March 2010

An experiment was carried out to investigate rate of shell secretion in two groups of hens selected for differences in shell deformation. Forty 50-wk-old Single Comb White Leghorn hens from two groups shown to produce eggs differing in shell thickness were fed a 3.5% Ca diet. Hens in their third to fifth ovulatory cycle of a sequence were intubated with 15 μCi of 45Ca 0.5 h post-oviposition. At 6, 12, 15 and 24 h, post-intubation blood was collected from five hens, which were subsequently euthanized, and bone samples were taken.Hens producing thick shells had higher (P < 0.05) plasma proteins, although there was no difference (P > 0.05) in plasma Ca or plasma protein-bound phosphorus content. While plasma 45Ca specific activity decreased (P < 0.05) with post-intubation time, there were no differences (P > 0.05) in plasma 45Ca specific activity between the two groups of hens. There were no differences (P > 0.05) in Ca reserves of bone ends or medullary bone alone or combined for hens secreting either thick- or thin-shelled eggs, nor were there any changes (P > 0.05) in these parameters with post-intubation time. Total 45Ca and 45Ca specific activity of both bone ends and medullary bone decreased as the ovulatory cycle proceeded. Regression analysis showed that the rate of depletion of 45Ca from the bone compartment, as indicated by the slope coefficient, was greatest for hens selected to produce thicker shells (Y = 13.8 − 3.11X1, R2 = 0.351, RSD = ± 4.917 for thick-shelled hens; Y = 6.7 − 0.95X1, R2 = 0.360, RSD = 1.1479 for thin shelled hens, where Y is the percentage 45Ca-intubated bone; and X1 is the time in hours). Key words: Calcium, shell formation, bone
Effects of feeding added protein and fat on feedlot performance and carcass quality in large frame steers
Authors: Engstrom D. F. , Goonewardene L. A. , Volek R. , Grimson R. E. , Stilborn R. P. , McKinnon P. J.
Published: March 2010

Feeding added protein to large frame steers increased average daily gain (ADG) and intake but had no effect on dry matter:gain, carcass weight and carcass quality. Including 2% added fat had no effect on ADG and carcass traits. However, feeding 4% added fat increased ADG to 56 d, although ADG overall and carcass quality were not influenced. Key words: Feeding, protein, fat, steer, carcass quality, average daily gain
Effect of live-yeast culture and lasalocid supplementation on performance of growing–finishing steers fed alfalfa-silage, corn-silage and high-grain diets sequentially
Authors: Mir P. S. , Mir Z.
Published: March 2010

Trials were conducted to determine the effect of supplementing feedlot diets with live-yeast culture (YC), lasalocid (LAS) or YC + LAS on intake, growth and carcass characteristics of steers. Dietary additives in either 96% corn-silage or 75% dry-rolled barley-based diets increased (P < 0.05) final weights and carcass weights of steers. Key words: Yeast, lasalocid, steers, carcass quality, growth
The effect of mixing, feed restriction and genotype with respect to stress susceptibility on pork carcass and meat quality
Authors: Murray A. C. , Jones S. D. M.
Published: March 2010

The effects of genotype for stress susceptibility with respect to the halothane gene (PSS genotype: NN = homozygous normal, Nn = heterozygous, nn = homozygous recessive), in combination with fasting and mixing during the 24 h prior to shipping for slaughter upon the carcass traits and quality of the longissimus muscle were investigated using a total of 229 pigs. In comparison to pigs of the NN genotype, pigs of the nn genotype had higher warm carcass yield, cold carcass yield, yield of the major cuts and lean yield of the major cuts by 47, 39, 5 and 15 g kg−1, respectively. Pigs of the Nn genotype had 30 and 8 g kg−1 higher warm carcass yield and yield of major cuts, respectively, than did NN pigs. Pigs of the nn genotype had 178 g kg−1 and pigs of the Nn genotype had 66 g kg−1 more total lean in the major cuts than NN pigs but these differences were not detected by the carcass grading system. Mixing and fasting both caused live-animal weight losses and reduction of warm carcass yield. Fasting had the greater influence, decreasing live animal weight by 54 g kg−1 and the warm carcass yield by 12 g kg−1 in comparison to the unmixed, unfasted pigs. Combined fasting and mixing for 24 h decreased live animal weight by 62 g kg−1 and the warm carcass yield by 19 g kg−1 in comparison to the unmixed, unfasted pigs. Pigs of both nn and Nn genotypes produced poorer muscle quality than did those of the NN genotype. Fasting of pigs for 24 h pre-slaughter alleviated the PSE problem to a small extent. Mixing, with or without fasting, improved muscle quality of pigs of the Nn and nn genotypes. However, such gains in meat quality due to mixing and/or fasting are negated by the decreases in the carcass yield, by the additional carcass damage due to fighting and finally by their possible detriment to animal welfare. Key words: Mixing, fasting, halothane genotype, carcass, pork quality, pigs
Sialic acid contents in chicken eggs and tissues
Authors: Nakano K. , Nakano T. , Ahn D. U. , Sim J. S.
Published: March 2010

Sialic acid contents were determined as potential commercial sources in egg fractions (yolk, white, chalaza, yolk membrane and shell membrane), oviduct, and rooster comb and wattle tissues by the periodate–thiobarbituric acid method with a partial modification. In egg fractions, the concentration of sialic acid was highest (P < 0.05) in yolk membrane (13.7 ± 0.5 μg mg−1), higher (P < 0.05) in chalaza (5.1 ± 0.2 μg mg−1) and yolk (5.2 ± 0.4 μg mg−1) than in white (2.2 ± 0.3 μg mg−1), and lowest (P < 0.05) in shell membrane (0.6 ± 0.1 μg mg−1). In oviduct, the concentration of sialic acid was lower (P < 0.05) in magnum (3.7 ± 0.6 μg mg−1) than in the remaining regions, among which the concentration was similar (5.6 ± 0.3 μg mg−1). The sialic acid concentration was similar in comb and wattle tissues (2.6 ± 0.4 μg mg−1). Sialic acid containing glycopeptide fractions were isolated from yolk, white, and comb and wattle tissues by papain proteolysis and gel chromatography. Key words: Sialic acid, egg, oviduct, comb, wattle
Investigation of genotype-environment interaction by cluster analysis in animal experiments
Authors: Lin C. Y. , Lin C. S.
Published: March 2010

The conventional ANOVA (F ratio of GE interaction mean squares to error mean square) provides a means to test if GE interaction is significant, but it does not tell us which factor levels are significantly different or how they are interacting. To answer the latter question, plant researchers developed a technique to group genotypes for similarity of GE interactions and through the resulting groups to explore the GE interaction structure. The basic idea of the technique is to stratify genotypes (or environments) into subgroups such that GE interactions among genotypes (or environments) are homogeneous within groups but heterogeneous among groups. This technique is introduced in this paper using an animal experiment as an example for illustration. The possibilities and limitations of applying this technique to animal data are also discussed. Key words: Genotype-environment interaction, cluster analysis
Counteraction of the follicular inhibitory effect of follicular fluid by administration of FSH in heifers
Authors: Bergfelt D. R. , Plata-Madrid H. , Ginther O. J.
Published: March 2010

The hypothesis that a factor in follicular fluid suppresses follicular growth independently of reduced systematic FSH concentrations in cattle was tested in a 2 × 2 factorial designed experiment (n = 5 heifers group−1). Treatment, at 12-h intervals, began on day O (ovulation) and ended on day 1. Mean (± SEM) diameter of the largest follicle, averaged over all days, and maximum diameter attained on days 0–9 was smaller (P < 0.05) in heifers given follicular fluid (8.4 ± 0.4 and 12.4 ± 1.0 mm, respectively) than in heifers given either saline (10.3 ± 0.6 and 14.8 ± 0.6 mm) or follicular fluid plus FSH (10.7 ± 0.6 and 16.8 ± 0.4 mm). The day-to-day mean diameter profiles of both the largest and second-largest follicles for days 0–9 were similar among heifers given saline, follicular fluid plus FSH, and FSH alone, whereas the follicle profile was reduced in heifers given follicular fluid alone. Mean follicle diameters were smaller (P < 0.05) on days 4–9 and days 2 and 5 in heifers given follicular fluid than in heifers given either saline or follicular fluid plus FSH. The results did not support the hypothesis, since exogenous FSH overrode follicular inhibition induced by follicular-fluid treatment. Key words: Cattle, follicles, follicular fluid, FSH