bluuebunny/crossref_metadata_2025 huggingface dataset:
The behaviour of pigs weaned at 12 and 21 days of age from weaning to market
Authors: Gonyou H. W. , Beltranena E. , Whittington D. L. , Patience J. F.
Published: March 2010

Segregated early weaning (SEW) of piglets at less than 21 d of age is becoming an increasingly common procedure in North America. Such early weaning has become commercially feasible through the use of highly palatable nursery diets, which increase intake during the week following weaning. A study was conducted to determine the effects of such early weaning on the behaviour of piglets. Thirty-two litters were weaned at either 12 or 21 d of age. During the subsequent 48 h, pigs were videotaped and the tapes used to determine the development of eating behaviour using scan sampling. Pigs weaned at 21 d of age spent more time eating than those weaned at 12 d of age (P < 0.05). Although both age groups ate little (<3% of time) during the initial 12 h, those weaned at 21 d of age began increasing time spent eating during the subsequent 12 h and reached a normal level of approximately 9% of time spent eating by 36 h post-weaning. No noticeable increase in eating occurred among those weaned at 12 d of age until after 36 h, at which point the level quickly increased to 10% of time. During the subsequent 6 wk, live scan sampling revealed that pigs weaned at 12 d of age spent more time eating (11.6 vs. 10.5%; P < 0.05), drinking (1.65 vs. 1.22%; P < 0.01), nosing other pigs (1.23 vs. 0.74%; P < 0.01), and chewing on objects (2.48 vs. 2.33%; P < 0.01) than did those weaned at 21 d of age. Nosing of other pigs peaked during the 2nd and 3rd weeks after weaning in both weaning age groups, but the maximum level was approximately twice as high for piglets weaned at 12 as for those weaned at 21 d of age. Piglets weaned at 12 d of age continued to nose and chew other piglets more during the growing/finishing period than did those weaned at 21 d of age (P < 0.05). Partial, within-pen, correlations indicated that less-active pigs grew faster (r = 0.18) and were less likely to nose or chew other pigs (r = –0.15 and −0.26, respectively). Nosing other pigs and being nosed were negatively correlated (r = −0.17), but neither was correlated with rate of gain (P < 0.05). The delay in eating and the higher incidence of anomalous behaviours by the earlier weaned pigs suggest that additional improvements in early weaning management are desirable. Key words: Pigs, behaviour, weaning, age
Cannulation of the distal ileum in ponies
Authors: Coleman R. J. , Mathison G. W. , Ingram J. , Bell D.
Published: March 2010

A simple "T" cannula was placed in the distal ileum of nine mature pony geldings. With the animal under general anesthesia, the plastisol (polyvinyl chloride) cannula was placed in the distal ileum, and exteriorized caudal to the 16th rib. The cannula surgery was simple and recovery was rapid, resulting in ponies that could be used in nutritional studies within 1 mo of surgery. With regular maintenance cannulated ponies can remain viable for periods of time greater than 1 yr. Key words: Equine, distal ileum, small intestine, cannulation simple "T" cannula
Influence of dietary selenium source on growth performance, and carcass and meat quality characteristics in pigs
Authors: Wolter B. , Ellis M. , McKeith F. K. , Miller K. D. , Mahan D. C.
Published: March 2010

Inorganic (sodium selenite) and organic (selenium-enriched yeast) dietary selenium sources were compared in a performance study using 48 growing–finishing pigs. There was no effect of selenium source on growth and meat-quality traits. The organic selenium source reduced backfat thickness at the last lumbar vertebra, but not at other positions, and increased loin-eye area. Key words: Meat quality, pigs, selenium source
Bunk attendance of feedlot cattle monitored with radio frequency technology
Authors: Gibb D. J. , McAllister T. A. , Huisma C. , Wiedmeier R. D.
Published: March 2010

Bunk attendance of 72 feedlot cattle (412 ± 23.6 kg) was monitored for 86 d using radio frequency technology. Late morning and late afternoon were confirmed as primary ad libitum feeding periods. The system detected differences (P < 0.005) in feeding behaviour in response to level of feeding and frequency of meals. Key words: Feeding behaviour, limit feeding, feeding frequency
Degradability of alfalfa saponins in the digestive tract of sheep and their rate of accumulation in rumen fluid
Authors: Mathison G. W. , Soofi-Siawash R. , Klita P. T. , Okine E. K. , Sedgwick G.
Published: March 2010

Two experiments were conducted to examine the fate of alfalfa saponins in the digestive tract of sheep. In the first experiment 14.4 or 28.8 g saponins were administered intraruminally daily, which provided 62 and 78% of the total saponin entering the rumen. Degradabilities of the saponins in the total digestive tract were 96.0 and 97.9% (P = 0.13), respectively, but no attempt was made to determine how closely the products of degradation were related to the original molecules. In the second experiment, the rate of release of saponins from alfalfa into rumen fluid was measured in the presence and absence of viable bacteria. When no viable bacteria were present 74% of the saponins in the alfalfa appeared in rumen fluid after 8 h of incubation and this amount was unchanged at 24 h. Rate of release did not follow first order kinetics, rather an amount equivalent to approximately 8% of the original saponin concentration accumulated in the fluid each hour over the 8-h period. After 4 h, saponin concentrations in rumen fluid were decreased in the presence of viable bacteria indicating microbial metabolism was occurring. Final accumulation of saponins in the rumen fluid after 24 h incubation was 62% of that originally present in alfalfa samples when viable bacteria were present. It was concluded that saponins were rapidly released into rumen fluid and extensively degraded in the digestive tract. The implications of these observations on ruminant bloat are discussed. Key words: Alfalfa, saponins, digestibility, bloat, rumen fluid, bacteria
Assessment of inhibitory effects of ruminal fluid on biological activity of steroidal saponins using hemolytic assay
Authors: Wang Y. , McAllister T. A. , Cheeke P. R. , Cheng K.-J.
Published: March 2010

In vitro studies demonstrated that cell-free ruminal fluid inhibits the saponin-based hemolytic activity of yucca extract, and that the inhibitory factor isolatable with the protein fraction of ruminal fluid is not heat labile. Hemolysis assay is not reliable for assessing saponin activity in ruminant nutrition applications. Key words: Yucca extract, ruminal fluid, hemolysis, saponins
Whole-body protein metabolism and plasma profiles of amino acids and hormones in growing barrows fed diets adequate or deficient in lysine
Authors: Roy N. , Lapierre H. , Bernier J. F.
Published: March 2010

Eighteen growing barrows (body weight: 26.6 ± 1.4 kg) were assigned (day 0) to one of three levels of dietary lysine: to be deficient (0.45%; L1), to achieve (0.75%; L2), or to exceed (0.98%; L3) National Research Council (NRC) (1988) lysine requirements (as-fed basis), according to a completely randomized block design. Nitrogen balance was measured over a 6-d period (days 10 to 16). On day 16, pigs were moved into respiratory chambers and received a 6-h continuous i.v. infusion of NaH13CO3 (1.66 µmol h−1 kg−1, preceded by a priming dose of 2.35 µmol kg−1) on day 17. The following day, pigs received an i.v. infusion of L-[1-13C]leucine (11.07 µmol h−1 kg−1, preceded by a priming dose of 11.07 µmol kg−1). Average daily gain and nitrogen retention increased (P < 0.10) by 36 and 20%, respectively, as dietary lysine content increased from L1 to L3. Leucine irreversible loss rate increased (P < 0.05) by 14% from diets L1 to L3, while leucine oxidation remained constant (P > 0.10) between diets. In consequence, fractional oxidation decreased (P < 0.05) by 20%, from L1 to L3. Protein synthesis and degradation increased (P < 0.05) from diets L1 to L2, but the values for the diets L2 and L3 were similar. Insulin levels tended to increase from L1 to L3 (P < 0.10), while that of triiodothyronine decreased from diets L1 to L3 (P < 0.05). Daily feed intake, nutrient digestibility, energy metabolism and plasma concentrations of insulin-like growth factor 1 and growth hormone were not affected (P > 0.10) by treatments. In conclusion, the improvement in protein gain associated with increasing lysine supplementation to achieve lysine requirement involved a general stimulation of whole-body turnover, protein synthesis being increased to a larger extent than protein degradation. Key words: Pigs, protein, metabolism, hormone, lysine, leucine
Cellular, molecular and physiological aspects of leptin: Potential application in animal production
Authors: Hossner Kim L.
Published: March 2010

This review encompasses the biochemistry and physiology of the newly discovered adipose hormone, leptin. Leptin appears to fulfill the role of the long sought after "lipostat", which functions to regulate energy intake in relation to body stores in the form of fat. Leptin is a 16 000 Dalton polypeptide which interacts with specific receptors in the hypothalamus to regulate food intake and body fat stores. Leptin receptors exist in several forms, which can be divided into those with small cytoplasmic domains and one with a single long cytoplasmic tail. The latter is thought to mediate most of leptin's effects, acting through the JAK-STAT signal transduction pathway. Several reports have shown direct effects of leptin on tissues with the short form of the leptin receptor. Specific effects of leptin on appetite, energy metabolism and reproduction are reviewed. Leptin may prove to be most useful to animal producers as a stimulant of the reproductive system or as a molecular marker to genetically select livestock for improved reproductive capacities or carcass characteristics, while leptin antagonists may improve metabolic rate and body composition. Key words: Leptin, obese protein, leptin receptor, review, livestock production
A simple, on-line processing method for improving beef tenderness
Authors: Aalhus J. L. , Best D. R. , Costello F. , Jeremiah L. E.
Published: March 2010

Traditional beef carcass suspension by the Achilles tendon allows considerable rigor shortening and decreased tenderness in some of the major muscles of the back and hindlimb. To reduce this effect, 60 market-weight (480 ± 42 kg) Hereford Angus cross cattle (30 steers and 30 heifers) of an estimated Canada 1 yield grade were used to compare the effects on meat quality of an on-line altered suspension (OLAS) under CC (2 °C for 24 h) and BC (−20 °C for 3 h with wind speed of 2.32 m s−1) conditions. Regardless of the rate of chilling, OLAS resulted in significant improvements in shear force in the longissimus thoracis et lumborum and inside round (decreases ranged from 1.13 kg to 2.38 kg in the muscles studied). Longissimus thoracis et lumborum steaks from OLAS sides were rated significantly higher by a laboratory panel for initial tenderness, amount of connective tissue, overall tenderness and overall palatability (P ≤ 0.01). In addition, compared with conventional suspension, OLAS reduced (P ≤ 0.01) the proportion of unacceptable scores for initial tenderness (28.3 to 7.5%), overall tenderness (19.2 to 2.5%) and overall palatability (17.5 to 3.3%). Hence OLAS appears to have considerable potential to improve tenderness in the major muscles of the back and hip without compromising the quality of the smaller, contralateral muscles. Key words: Altered suspension, beef tenderness, blast chilling
Effect of feed form, formulation, and restriction on the performance of laying hens
Authors: Scott T. A. , Silversides F. G. , Tietge D. , Swift M. L.
Published: March 2010

A laying trial was performed with 1440 DeKalb® hens caged at 18 wk of age to test the effect of feed form (expanded pellets or mash) and type of formulation (for crude protein [CP] or for specific amino acids[AA]), and five levels of feed restriction applied at either 24 wk or 32 wk of age. Formulation for CP rather than AA content resulted in 4.4% greater egg production and 7.1% greater production of egg mass in hens fed mash and 4.0% better feed efficiency in hens fed both mash and pellets. Hens fed mash had 2.3% higher feed consumption, suggesting that the hens may prefer mash. Feed restriction reduced body weight and hen–day egg production proportionate to the restriction level, but egg weight was reduced only slightly. These data suggest that care should be exercised in formulating for AA content rather than for CP, especially if feed intake is reduced. This strain of hens was very successful at regulating its feed intake for maximum production, and even a slight feed restriction produced a negative effect on production. Key words: Laying hens, feed restriction, feed form, feed formulation, protein level
Maximum loading density of loose horses
Authors: Whiting Terry
Published: March 2010

An observational study was conducted to document common space allowance given to horses safely transported en masse. Observations of loaded vehicles support increasing the maximum density in mass-per-area as the average horse body weight increases are safe. The recommended loading density for horses loaded in groups is y = (54.837)W0.325, where y = density in kg m−2 and W = average animal weight in kilograms. Key words: Animal transportation, space allowance, loading density, horse
The calpain system and skeletal muscle growth
Authors: Goll Darrel E. , Thompson Valery F. , Taylor Richard G. , Ouali Ahmed
Published: March 2010

The first protein of a group of proteins now identified as belonging to the calpain system was purified in 1976. The calpain system presently is known to be constituted of three well-characterized proteins; several lesser studied proteins that have been isolated from invertebrates; and 10 mRNAs, two each in Drosophila and C. elegans and six in vertebrates, that encode proteins, which, based on sequence homology, belong to the calpain family. The three well-characterized proteins in the calpain family include two Ca2+-dependent proteolytic enzymes, µ-calpain and m-calpain, and a protein, calpastatin, that has no known activity other than to inhibit the two calpains. A substantial amount of experimental evidence accumulated during the past 25 yr has shown that the calpain system has an important role both in rate of skeletal muscle growth and in rate and extent of postmortem tenderization. Calpastatin seems to be the variable component of the calpain system, and skeletal muscle calpastatin activity is highly related to rate of muscle protein turnover and rate of postmortem tenderization. The current paradigm is that high calpastatin activity: 1) decreases rate of muscle protein turnover and hence is associated with an increased rate of skeletal muscle growth; and 2) decreases calpain activity in postmortem muscle and hence is associated with a lower rate of postmortem tenderization. This article summarizes some of the known properties of the calpain system and discusses the potential importance of the calpain system to animal science. Key words: Calpain, calpastatin, postmortem tenderization, skeletal muscle growth
Effects of dietary fish silage and fish fat on growth performance and sensory quality of growing-finishing pigs
Authors: Kjos N. P. , Skrede A. , Øverland M.
Published: March 2010

Thirty-six growing-finishing pigs, with an average initial weight of 24.8 kg ± 2.6 SD, were allocated to six groups to determine the effect of fish silage and fish fat in the diet on performance, carcass characteristics and sensory quality. The treatments were either a control diet, or one of three diets containing 50 g kg−1 fish silage and different levels of fish fat (2.5, 5.5 or 9.5 g kg−1). The diets were either fed until the time of slaughter (treatments CO, FSA1, FSB1 and FSC1), or until 60 kg liveweight followed by the control diet (the diets with 5.5 [treatment FSB2] and 9.5 g kg−1 fish fat [treatment FSC2]). Pigs were slaughtered at 98.7 kg ± 4.5 SD. No significant differences in growth performance or carcass quality were found among diets. The contents of the fatty acids C20:1 and C22:6 in the subcutaneous fat was increased by the dietary inclusion of fish silage. The total level of omega-3 fatty acids were highest for the 9.5 and the 5.5 g kg−1 fish fat diets when they were fed until slaughter. High blood plasma levels of vitamin E in pigs fed diets containing fish silage and 5.5 g kg−1 fish fat may explain these differences, and thus indicate the importance of vitamin E status when feeding diets containing fish silage and fish fat. The diets containing 2.5 and 9.5 g kg−1 fish fat until slaughter caused off-flavour of bacon after both 1 and 6 mo of frozen storage, and of loin muscle after 6 mo frozen storage. Curiously, the diet with fish silage and 5.5 g kg−1 fish fat could be used in diets for growing-finishing pigs without adverse effects. Key words: Fish silage, fish fat, growing-finishing pigs, growth performance, carcass characteristics, sensory quality
Impact of pasture type on methane production by lactating beef cows
Authors: McCaughey W. P. , Wittenberg K. , Corrigan D.
Published: March 2010

In order to determine the quantity of methane (CH4) produced by lactating beef cows on pasture, 16 Hereford–Simmental first-calf heifers with a mean weight of 511.2 ± 5.8 kg were randomly selected from a larger group of cows (n = 60) on a grazing management experiment and used to evaluate the effects of pasture type on ruminal CH4 production using the sulfur hexafluoride (SF6) tracer-gas technique. Pasture treatments consisted of two pasture types, alfalfa-grass [78% alfalfa (Medicago sativa L.) – 22% meadow bromegrass (Bromus biebersteinii Roem and Schult.)] or 100% meadow bromegrass at each of two fertility levels (either unfertilized or soil test recommended fertilizer levels) with two replications of each pasture treatment (8 pastures). Cows were managed using a "put and take" stocking system to leave equal residual herbage mass on all treatments following the grazing period in each paddock. During the 69-d grazing season, two cows from each pasture were sampled to determine daily forage intake and CH4 production on four occasions. The chemical composition of diets differed between pasture types and sampling periods. Dry matter intake was greater for cows grazing alfalfa–grass pastures than for cows grazing grass-only pastures (11.4 vs. 9.7 kg DM d−1. P < 0.018). However, methane production was greater for cows grazing alfalfa–grass pastures than for cows grazing grass-only pastures (373.8 vs. 411.0 L CH4 d−1. P < 0.008). Consequently, energy lost through eructation of CH4 was less for cows grazing alfalfa–grass pastures than it was for cows grazing grass-only pastures (7.1 vs. 9.5% of GEI; P < 0.001). Key words: Methane, cattle, environment, digestion efficiency, pasture, forage
Direct transesterification of lipids from feedstuffs and ruminal bacteria
Authors: Whitney M. B. , Hess B. W. , Kaltenbach J. E. , Harlow H. J. , Rule D. C.
Published: March 2010

Direct transesterification of feedstuffs, browse plants, and ruminal bacteria was compared to transesterification of solvent extracted lipids. Weight percentages were of similar magnitude between procedures. Direct transesterification often produced higher concentrations of fatty acids. Results indicate that direct transesterification is an acceptable method for analysis of total fatty acids. Key words: Transesterification, lipids, feedstuffs, bacteria
The use of double-muscled cattle breeds in terminal crosses: Animal performance and blood metabolites
Authors: Seoane J. R. , Lapierre H. , Roy G. L.
Published: March 2010

Eighty-nine calves born of dams from British (50% Hereford and 50% Red Angus) and Continental (50% Simmental and 50% Maine Anjou) breeds crossed with Charolais (CH), Belgian Blue (BB) and Piedmontese (PM) sires were used to evaluate the productivity of using double-muscled cattle in terminal crosses. Breed of sire did not exert a significant effect on any parameter measured before weaning. Calving difficulty was related to breed of dam, being higher in British than in Continental dams (P < 0.05) and tended to be higher for male than for female calves (P < 0.10). Average daily gains to weaning and weight corrected at 200 d were higher for male than for female calves (P < 0.05), and for calves from Continental dams than for those from British dams (P < 0.05). Average daily gain during backgrounding was higher for CH than for PM-sired calves (P < 0.05). Also, ADG in feedlot (backgrounding + fattening) was higher for male than for female calves (P < 0.05). Slaughter weight and dressing percentage were higher in calves from Continental dams than in those from British dams (P < 0.05). At similar backfat thickness, slaughter weight was higher in male than in female calves (P < 0.05). Total plasma cholesterol, HDL cholesterol and triglycerides were higher in PM sired cattle than in those sired by CH (P < 0.01 to 0.10). Similarly, cattle from British dams presented higher values of plasma cholesterol, HDL cholesterol and LDL cholesterol than cattle from Continental dams (P < 0.01 to 0.05). Insulin and IGF-I values increased with age (P < 0.01). Plasma insulin concentrations during fattening were higher for PM than for BB or CH sired cattle (P < 0.05), for cattle from Continental than from British dams (P < 0.01) and for males than for females (P < 0.01). During fattening, IGF-I values were higher in male than in female cattle (P < 0.01). The use of double-muscled sires in terminal crosses resulted in little effect on performance of the progeny. Key words: Double-muscled, terminal crosses, Belgian Blue, Piedmontese
Genetic and phenotypic parameter estimates between production, feed intake, feed efficiency, body weight and linear type traits in first lactation Holsteins
Authors: Kennedy B. W. , Dekkers J. C. M. , Moore R. K. , Jairath L.
Published: March 2010

Production and feed intake data on 36 115 first lactation Holstein cows obtained from Quebec Dairy Herd Analysis Service were combined with conformation data from the Holstein Association of Canada to estimate genetic correlations among production, energy intake, and conformation traits. Traits considered were 305-d milk yield, 305-d grain energy and total energy intake, feed efficiency (fat corrected milk yield/total energy intake), body weight at calving, capacity, size, stature, rump width and final score. Genetic and phenotypic parameters were estimated using Restricted Maximum Likelihood based on two-trait animal mixed model analyses. The model contained fixed effects of herd-year, season of calving, age of calving, sire group and a random animal genetic effect. Estimates of heritability were within the published range for all traits. Of the conformation traits examined, capacity, size and stature had the highest correlations with body weight, with phenotypic correlations between 0.36 and 0.43, and genetic correlations between 0.61 and 0.79. Feed efficiency was negatively correlated to all body size measures, both phenotypically (−0.01 to −0.29) and genetically (−0.31 to −0.53), but most significantly with body weight, capacity, size, and stature. Fat-corrected milk yield showed negligible phenotypic and low to moderately negative genetic (−0.07 to −0.29) correlations with body weight and related type traits. Total energy intake was positively related to all measures of body size, most notably body weight, while grain energy intake had moderately negative genetic correlations (−0.20 to −0.40) with the same body size traits. Because of their detrimental relationships with feed efficiency, negative selection emphasis should be placed on body weight and the related type traits capacity, size and stature. Capacity, size and stature are of moderate utility when selecting indirectly for body weight, total energy intake and feed efficiency. Key words: Dairy cattle, genetics, production, conformation, feed efficiency
Quality control and safety of animal products
Authors: Miller M. A.
Published: March 2010

This paper discusses the new animal drug approval process regulated by the Center for Veterinary Medicine (CVM), Food and Drug Administration (FDA) of the United States. The Center for Veterinary Medicine of FDA considers two criteria in ensuring the human food safety of edible animal products: i) safety of the chemical residues and ii) for antimicrobial products, microbiological safety including changes in bacterial pathogen load and resistance pattern. The hazard associated with animal drug products of non-carcinogenic compounds is assessed by conducting a standard battery of toxicology test, whereas the hazard from the carcinogenic potential of compounds is evaluated based on structure, results of genetic toxicity tests, and toxicology studies. Post approval monitoring is carried out to ensure that the animal drugs are being used properly after their approval. Particular concern is given to those eliciting an "acute" toxic reaction at relatively low levels. The other aspect of food safety regulated by CVM of FDA is microbiological safety, especially to antimicrobial drugs used at subtherapeutic levels in feeds. The studies are designed by FDA to ensure that antibiotic treatment of food-producing animals does not alter pathogen load or resistance pattern of pathogens. Two studies are generally performed: i) the salmonella shedding study, which addresses the effect of drug treatment on the excretion of salmonella in the feces of animals artificially infected with salmonella; and ii) the coliform resistance study, which monitors the effect of the drug on the resistance pattern of E. coli present in the endogenous fecal flora. After a retrospective study of the microbiological safety over past 20 yr, CVM of FDA is planning to revise some microbiological safety studies with focuses on: i) pathogen load, pathogen excretion and microorganism resistance pattern at the time of slaughter; and ii) susceptibility studies on products that have utility in human medicine. Key words: Animal drug, food safety, antibiotic
Use of forage inoculants with or without enzymes to improve preservation and quality of whole crop barley forage ensiled as large bales
Authors: Nia S. A. Moshtaghi , Wittenberg K. M.
Published: March 2010

The effects of forage additives, applied to bales wrapped at either 2 or 10 h post-baling, on preservation and quality of whole barley crop ensiled as large bales were investigated. Forage was cut at the early milk stage and allowed to wilt over a 24-h period to 47% DM. Bales were allocated on the basis of baling sequence to one of three additives treatments: without inoculant (Control); treated with a microbial inoculant, Lactobacillus plantarum and Pediococcus cerevisiae (LpPc); or treated with Lactobacillus plantarum and Pediococcus cerevisiae, plus cellulase and pectinase (LpPcE). An equal number of bales (n = 18) representing each treatment group were wrapped at either 2 or 10 h post-baling. All bales were core sampled at baling and on days 1, 2, 3, 6, 9, 13, 17, 29, 64, 92, 252 and 308 post-baling. Bales were weighed prior to being wrapped and when removed from storage to measure DM and nutrient losses during storage. During wrapping, a thermocouple wire was inserted in each bale to monitor bale temperature. Time of wrapping did not affect nutrient composition or ensiling characteristics of silage. Application of forage additives had no effect on nutrient profile or recovery, however, silage treated with LpPc inoculant had lower (P < 0.05) ammonia N compared with untreated or treated with LpPcE silage. Storage temperature of bales representing all treatments did not exceed 28 °C but were approximately 2 to 3 °C higher in the Control than treated silage for the first 3 d post-ensiling. Silage treated with forage additives had a lower (P < 0.05) pH and an increase (P < 0.05) in concentrations of lactic and total acids. Ethanol and 2,3 butanediol levels were higher (P < 0.05) in untreated silage compared with inoculated silage. Silage treated with forage additives were more stable and took 5, 9 and 12 d to heat after exposure to air for Control, LpPc and LpPcE silage, respectively. Results from this study indicated that treatment with microbial inoculants was beneficial in preserving whole crop barley ensiled as large bales. Addition of enzymes to microbial inoculant did not have further beneficial effect on quality of large bale silage. Key words: Silage, large bale, whole crop barley, forage additives, ensiling characteristics
Effects of exogenous fibrolytic enzymes, α-bromoethanesulfonate and monensin on fermentation in a rumen simulation (RUSITEC) system
Authors: Dong Y. , Bae H. D. , McAllister T. A. , Mathison G. W. , Cheng K.-J.
Published: March 2010

The effects of exogenous fibrolytic enzymes, α-bromoethanesulfonate (BES) and monensin on fermentation and digestibility of grass hay were examined using two rumen simulation technique (RUSITEC) devices, each equipped with eight 820-mL fermenters with a liquid dilution rate of 0.73 d−1. Grass hay (10 g d−1) was fed either untreated or pre-treated with 0.2 g each of cellulase and xylanase, and in combination with no chemical or daily dosing of 20.5 µmol monensin, 20.5 µmol BES or 41 µmol BES. Pretreatment of hay with the fibrolytic enzymes increased (P < 0.05) organic matter (OM), cellulose and hemicellulose digestibilities by 9, 15, and 20%, respectively, and increased (P < 0.05) methane production per gram digestible OM by 43%. With the enzyme treatment, both β-endoglucanase and xylanase activities were enhanced (P < 0.05). Application of the enzymes promoted (P < 0.05) the growth of methanogenic bacteria, with no effect on total bacterial or cellulolytic bacterial populations. α-Bromoethanesulfonate did not influence digestibility, but depressed (P < 0.005) methane production by 51%. Addition of BES inhibited (P < 0.05) growth of methanogenic bacteria, with no effect on either the total or cellulolytic bacterial populations. Monensin depressed (P < 0.05) OM, cellulose and hemicellulose digestibilities by 15, 27 and 17%, respectively, and methane production by 78%. Treating grass hay with fibrolytic enzymes enhanced fiber digestion but also methane production. Including BES counteracted the methane production without affecting fiber digestion whereas monensin decreased both fiber digestion and methane production. Key words: Fibrolytic enzymes, α-bromoethanesulfonate, monensin, digestibility, methane, RUSITEC
Dexamethasone ester treatment alters insulin-like growth factor-I, its binding proteins and thyroid status in finishing calves
Authors: Bertozzi C. , Portetelle D. , Massart S. , Prandi A. , Darras V. , Room G. , Tassinari M. , Vleurick L. , Parmentier I. , Haezebroeck V. , Decuypere E. , Burny A. , Renaville R.
Published: March 2010

To improve carcass quality in finishing calves, some breeders use preparations containing corticoids alone or in association with other growth promoters. We have investigated the effects of dexamethasone treatment on insulin-like growth factor-I (IGF-I), IGF-binding proteins (IGFBP-2 and 3) and thyroid hormones (T3, T4, free T4). Limousine male calves were allocated to a control group (C) (n = 18) and a group (n = 18) that received dexamethasone esters (DEX). Blood and hepatic tissue samples were collected at slaughtering. Thyroid hormones and IGF-I plasma levels were measured by RIA and IGFBPs were evaluated by immunoblotting. Hepatic type I 5′deiodinase (5′D-I) activity was determined by enzyme assay and hepatic expression of mRNA for GH receptor, IGF-I, IGFBP-2, IGFBP-3 and type I deiodinase (D-I) was evaluated by dot blot analysis. Plasma IGF-I and IGFBP-3 levels were reduced by the DEX treatment (P < 0.001 and P < 0.01, respectively) while IGFBP-2 was unaffected. Significant plasma changes for IGF-I and IGFBP-3 were not corroborated by hepatic mRNA levels, for which only a slight non-significant decrease was noted. Growth hormone receptor mRNA expression was increased after treatment (P < 0.01). T3 plasma level was higher in DEX animals (P < 0.05) than in C calves. Finally, treatment increased 5′D-I activity in the hepatic tissue (P < 0.001) and seemed to also affect D-I mRNA expression (P = 0.1). In conclusion, dexamethasone ester injection in calves altered some of their endocrinological parameters; this could explain the catabolic action of corticoids in the bovine species. Key words: Calves, corticoids, IGF-I, IGFBPs, thyroid axis
The performance of primiparous and multiparous beef cows rearing single and simulated-twin calves
Authors: Small J. A. , Charmley E. , Kennedy A.D.
Published: March 2010

One hundred and eighteen Hereford-cross heifers (n = 70) and cows (n = 48) and their offspring were used to evaluate the impact of simulated twinning on weaned calf production and reproductive performance. Twin-calf rearing was simulated by the adoption of a second calf born within 24 h of the birth of the dam's natural calf. In each of 4 yr, cows calved in winter (January–February), were turned out in spring (late May) to rotationally graze grass-legume pastures until weaning in the fall (late September). From calving until turnout cows were given a forage-based diet consisting of either grass-legume silage or hay offered free choice, plus concentrate, the amount of which was 75 or 100% higher for dams in the simulated-twin (ST) than the single (S) treatment. All calves had access to the conserved forage and were given the concentrate ration as creep feed. Estrus detection was performed twice daily beginning 3 wk before and continuing for 4 wk into the breeding season, which consisted of AI for the first 25 d and bull service for the remaining 22 d. In years 2 and 3, the postpartum anestrous period was determined by serum progesterone concentrations. At weaning, S calves weighed more than natural or adopted calves in the ST treatment because weight gain was greater for S calves from birth to turnout. However calf production efficiency (total kilograms calf weaned per kilogram dam weight) was greater for primiparous and multiparous ST than S groups (primiparous 0.85 vs. 0.43 and multiparous 1.62 vs. 0.49; P < 0.05). The ST treatment had no negative effect (P > 0.05) on reproductive performance. As a research tool, this study suggests there are large potential benefits to beef cows raising two, as opposed to one calf. Simulated twinning poses severe management challenges and is not being proposed as a commercial option. However, advances in reproductive technology that could control twinning (e.g., transfer of an embryo a week following AI or twin-transfer of sexed embryos) mean that in future, twin rearing of beef calves may become a feasible option and this study provides valuable information on the post-natal management of cows rearing two calves. Key words: Simulated-twin, progesterone, post-partum, weaning, cow-calf, calves
Monitoring cattle behavior and pasture use with GPS and GIS
Authors: Turner L.W. , Udal M.C. , Larson B. T. , Shearer S.A.
Published: March 2010

Precision agriculture is already being used commercially to improve variability management in row crop agriculture. In the same way, understanding how spatial and temporal variability of animal, forage, soil and landscape features affect grazing behavior and forage utilization provides potential to modify pasture management, improve efficiency of utilization, and maximize profits. Recent advances in global positioning system (GPS) technology have allowed the development of lightweight GPS collar receivers suitable for monitoring animal position at 5-min intervals. The GPS data can be imported into a geographic information system (GIS) to assess animal behavior characteristics and pasture utilization. This paper describes application and use of GPS technology on intensively managed beef cattle, and implications for livestock behavior and management research on pasture. Key words: Livestock behavior, electronics, grazing, forage, global positioning system, geographic information system
Farming the waters: Bringing aquatic plant and animal species to agriculture
Authors: Castell John
Published: March 2010

Aquaculture has a long history, with carp culture in Asia starting before 2000 BC and oyster culture in the Roman Empire before the time of Julius Caesar. However, it is clearly the past 40 yr that have seen the most dramatic expansion of aquaculture. The world's population now exceeds 6 billion people and is still growing at an alarming rate. The world's wild fish harvest has clearly peaked at or above the maximum sustainable yield of about 90 million t. Many fish stocks are suffering from over-fishing and there is little hope of any increase in the capture fisheries production. Though modern agricultural practices have been very efficient at increasing the per acre yields, the world is experiencing an alarmingly steady decrease in the amount of agricultural land devoted to food production. In the past 20–30 yr production of fish, molluscs, crustaceans and aquatic plants (aquaculture) has become an increasingly important means of producing food, and in some countries aquaculture production accounts for more than half of the total fishery harvest and is even as high as 90% in a few countries. I have reviewed the historical growth of aquaculture, compared the product value in various countries and reviewed aquaculture practices for a number of plant, molluscan, crustacean and fish species around the world. These culture technologies were compared and contrasted with agricultural practices. Finally, some predictions for the future of aquaculture development in Canada and the world have been made. Key words: Canadian aquaculture, history, salmon, fish farming, production statistics, fish culture technology
Ileal amino acid digestibility and estimates of endogenous amino acid losses in pigs fed rapeseed meal, sunflower meal and soybean meal
Authors: Jondreville C. , Broecke J. van den , Gâtel F. , Grosjean F. , Cauwenberghe S. Van , Sève B.
Published: March 2010

Four commercial samples of rapeseed meal (RSM), four of sunflower meal (SFM) and nine of soybean meal (SBM) were analysed and their ileal N and amino acid (AA) digestibilities in growing pigs were studied. Each batch was tested on four castrated male pigs weighing between 40 and 100 kg and fitted with an end-to-end ileo-rectal anastomosis. True ileal digestibility (TD) of AA was calculated by correcting apparent ileal digestibility (AD) for basal endogenous AA losses, measured by means of a protein-free diet. For RSM and SBM, total endogenous gut AA losses were estimated by a multiple regression model and real ileal digestibility (RD) of AA was calculated. In RSM, average TD of lysine, threonine and methionine were 70.7, 73.2 and 86.0%, respectively. These values were 80.0, 81.8 and 91.9%, respectively in SFM and 90.5, 86.8 and 93.0%, respectively, in SBM. In SBM, TD decreased (P < 0.05) with increases in the ratio of dietary acid detergent fibre (ADF) to AA contents. Expressed as g kg−1 dry matter (DM) intake, total endogenous gut N losses reached 4.7 to 6.4 for RSM and 1.9 to 3.5 for SBM. For SBM, they increased (P < 0.001) with dietary ADF concentration and RD of most AA decreased (P < 0.05) with the increase in the ratio of dietary neutral detergent fibre (NDF) to AA concentrations. Key words: Oilseed meal, ileal digestibility, amino acid, endogenous losses, pig
Effect of family housing of farmed silver foxes (Vulpes vulpes) in outdoor enclosures on some behavioural and physiological parameters
Authors: Ahola L. , Harri M. , Kasanen S. , Mononen J. , Pyykönen T.
Published: March 2010

Group housing of silver foxes in large housing systems has been claimed to promote the welfare of the species since it provides foxes with the possibility to express species-specific social and locomotor behaviour. In our study, silver foxes were housed in outdoor enclosures in family units consisting of a vixen and her four cubs. Foxes housed alone in traditional fox cages were used as control animals. Light hour activity, rectal temperature during human handling and restraint, activity of the HPA axis, heart and gastrocnemius muscle mass, succinate-dehydrogenase activity in gastrocnemius muscle and mechanical properties of tibia were determined from the foxes. The effect of different housing systems was more pronounced in the cubs than in the vixens, indicating the importance of earlier experiences on animals' performance. Both the increased rectal temperature and the increased activity of the HPA axis especially in the cubs housed in enclosures show that the foxes housed in enclosures had a greater fear level towards man than the foxes housed in cages. Furthermore, the foxes, especially the male cubs, raised in groups may have experienced stress due to social tension. Although the exercise-related parameters may indicate that a larger available space could be beneficial for the foxes' physical endurance, these parameters had no clear correlation with physiological welfare parameters. Key words: Behaviour, fear, physical endurance, HPA axis, stress-induced hyperthermia, Vulpes vulpes
In situ rumen degradation characteristics of sixty cultivars of barley grain
Authors: Khorasani G. R. , Helm J. , Kennelly J. J.
Published: March 2010

Our objectives were to determine the extent of genetic variability in the rate and extent of ruminal digestion among 60 cultivars of barley, and to evaluate the correlations between ruminal digestion characteristics and chemical composition and test weight of barley cultivars. Barley samples were ground through a 2-mm screen, and bags containing 1 g of ground grains were incubated in the rumen of three late-lactation Holstein cows with rumen cannulae for 0, 1, 2, 4, 8, 12, 16, and 24 h. The rate and extent of ruminal digestion were estimated. The insoluble DM fraction ranged from 33.4 to 56.4%, the degradable DM fraction ranged from 34.1 to 60.2%, and the rate of degradation of DM ranged from 0.200 h−1 to 0.624 h−1. Hulled barley cultivars had lower (P < 0.05) soluble and degradable fractions than hulless cultivars. The soluble fraction was positively correlated to starch content of barley cultivars (P = 0.01) and the degradable fraction was correlated to the test weight and CP content (P < 0.01). The observed variability in the ruminal digestion characteristics of barley cultivars indicates that genetic selection holds promise as a means of enhancing the nutritional quality of barley for ruminants. We also observed that 70% of the variation in digestibility could be explained by measures of bulk density, starch content, and kernel weight. Key words: Barley cultivars, in situ degradability
The effects of cross-fostering on growth rate and post-weaning behavior of segregated early-weaned piglets
Authors: Giroux S. , Robert S. , Martineau G.-P.
Published: March 2010

Cross-fostering involving piglets older than 2 d of age is often used in segregated early weaning (SEW) units to increase piglets' body weight homogeneity. This study was conducted to document the effects of such cross-fostering on weight gain, skin lesions, and post-weaning behavior of SEW piglets. Cross-fostering was done at 6 ± 1 d of age, in half of the 32 litters studied, by exchanging two piglets between pairs of litters. Piglets (n = 256) were weighed at birth, fostering, weaning (day 18 ± 1), and every week during the next month. The behavior of piglets was video-recorded during 3 h after weaning, and during 1 h on days 19, 20, 22, 24, 31, 38 and 45. Adopted piglets gained only 76% of the weight of non-adopted piglets between fostering and weaning (P < 0.001) and this difference persisted until day 45 (P < 0.05). Piglets from fostered litters fought less than control piglets during their first 2 d in nursery pens (P < 0.01) and skin lesions tended to be less frequent (P < 0.1). In all treatment groups, eating frequency was low on days 18 and 19 and increased abruptly on day 20. In conclusion, fostering impaired growth of piglets, but also facilitated their adaptation to unacquainted piglets after weaning. Key words: Pig, fostering, behavior, growth, welfare, segregated early weaning
Efficacy of new bacterial phytase in poultry diets
Authors: Leeson S. , Namkung H. , Cottrill M. , Forsberg C. W.
Published: March 2010

Phytase produced by Escherichia coli was fed to broiler chicks fed graded levels of available phosphorus (0.25–45%). A positive control involved Natuphos® a fungal phytase commonly used in poultry nutrition. Feeding diets with only 0.25% available phosphorus from 1 to 13 d of age resulted in reduced feed intake and weight gain, with associated loss in tibia weight, tibia ash and tibia phosphorus content (P < 0.01). Adding 600 IU phytase kg−1 diet corrected these problems, and both sources were equally efficacious for most parameters studied. Key words: Phosphorus, phytase, chicken
Selection for cow lifetime pregnancy rate using bull and heifer growth and reproductive traits in composite cattle
Authors: Mwansa P. B. , Kemp R. A. , Crews Jr D. H. , Kastelic J. P. , Bailey D. R. C. , Coulter G. H.
Published: March 2010

Genetic correlations of lifetime pregnancy rate with bull and heifer growth and reproductive traits in a beef composite population were estimated. Yearling scrotal circumference had an unfavorable genetic correlation (rg = −0.25) while yearling tonometer score was favorably related (rg = 0.22) to lifetime pregnancy rate. Heifer pregnancy rate, birth weight, weaning weight, yearling weight and age at puberty in heifers had significant genetic correlations (rg = 0.97, 0.58, 0.57, 0.33 and −0.21, respectively) with lifetime pregnancy rate. Lifetime pregnancy rate may be successfully predicted by easy-to-measure heifer growth traits. Using indices including scrotal and heifer growth traits, annual genetic change in lifetime pregnancy rate may be increased 3.1 times compared with direct selection. Key words: Scrotal circumference, tonometer, pregnancy, reproduction, puberty
Factors affecting productivity of sheep flocks in Ontario
Authors: Fiss C. F. , Sullivan P. G. , Kemp R. A.
Published: March 2010

Ontario Sheep Flock Improvement Program records from 1985 to 1989 on 216 670 lambs in 4894 flocks were used for this study. Flocks were required to have progeny from at least five ewes and the lams were grouped by breed type, ram breed, ewe size and birth year, all within producer. Death loss, percent of lambs fostered and effects associated with ewe age and size accounted for a significant portion of the variation in flock productivity. The ranking of breeding system and ram breed effects varied among mating programs. Flock productivity increased with increasing number of lambs born per ewe and ewe size. Flocks with ewes that averaged 59 mo of age had the highest productivity. Flock productivity increased 60 kg flock−1 (2.6 kg ewe−1) from 1985 to 1989. Key words: Sheep, flock productivity