bluuebunny/crossref_metadata_2025 huggingface dataset:
ALKALINE PHOSPHATASE ACTIVITY ASSOCIATED WITH THE WALLS OF DIFFERENT ORGANS OF THE GASTROINTESTINAL TRACT IN NEWBORN, YOUNG AND YEARLING BOVINES: EFFECTS OF DIET AND FASTING
Authors: FAY J. P. , CHENG K.-J. , COSTERTON J. W.
Published: March 2010

Alkaline phosphatase (APase) activity was assayed in tissue samples from the gastrointestinal tract (GIT) of newborn Holstein calves, and of 3- to 10-mo-old calves fed on milk only or starter-grower ration plus alfalfa hay. Statistical analysis of APase activity from different regions of the GIT showed effects of diet and site (P < 0.01) and an interaction of diet × site (P < 0.01) on APase activity. APase was high in the reticulo-rumen: intermediate in the omasum and the intestinal region: and low in the tongue, esophagus and abomasum. Within the same organ. APase differed considerably according to the location of the sites. Calves fed the fiber-containing diet had higher APase than those fed milk only. APase activity in the reticulo-rumen was much lower in newborn calves than in older calves, but in the other regions of the GIT, values were similar for the two groups. The effect of fasting on APase activity in rumen and abomasum walls of 20 yearling Hereford and Angus bulls fed on two different diets was also studied. In most cases, fasting decreased wall-associated APase activities. Interactions for breed × diet × site (P < 0.01), for breed × fasting × site (P < 0.01), and for diet × fasting × site (P < 0.05) on rumen APase activity, and for breed × diet × fasting (P < 0.01) on abomasum APase activity, were detected in this experiment. These variations in APase activity within the digestive tract are discussed in relation to the absorption capacity, degree of abrasion, and degree of keratinization of the tissues involved.
VOLATILE FATTY ACID PRODUCTION IN THE HINDGUT OF SWINE
Authors: KENNELLY J. J. , AHERNE F. X. , SAUER W. C.
Published: March 2010

Volatile fatty acid (VFA) production was determined using a continuous cecal isotope infusion system. In experiment 1, a control diet (diet 1) containing 12.9 MJ digestible energy (DE) per kilogram, 2.3% nitrogen and 4.8% crude fiber (CF) was fed to four pigs fitted with cecal cannulac. In experiment 2, the same control diet plus two diets (diets 2 and 3) containing, respectively, 27.3 and 52.07 alfalfa, 10.9 and 9.1 MJ DE. 9.9 and 15.0% CF were fed. In experiment 1, pigs were fed 2.7 kg daily of diet 1 in 24 equal feeds. In experiment 2, pigs were fed 2.4 kg daily of the three diets in three equal feeds at 8-h intervals. Following a 15-wk adaptation to diet 3, VFA production rates were again determined (exp. 3). In experiment 1, average VFA concentrations, in cecal fluid, were 79.1, 33.0 and 9.9 mmoles/L while VFA molar percentages were 64.8, 27.1 and 8.1 for acetate, propionate and butyrate, respectively. Net production rates for acetate, propionate and butyrate, respectively, for pigs fed diet 1, were 42.6, 14.3 and 4.9 mmoles/h. The average contribution of VFA to the maintenance energy requirement of the pig was calculated as 19.7%. In experiment 2, total VFA concentrations for pigs fed diets 1 and 2 were not significantly different. Pigs fed 15% CF had significantly lower total VFA concentrations than those fed diet 2. No significant dietary differences were observed in VFA production rates. However, pigs fed the 10% CF diet tended to have the highest production rates, with intermediate levels for pigs fed diet 3. The energy contribution of VFA for pigs fed 5, 10 and 15% CF was calculated as 10.1, 15.5 and 11.1% of the maintenance energy requirements, respectively. Following a 15-wk adaptation period to the high fiber diets, there was no evidence of increased VFA production.
THE INFLUENCE OF DIETARY ROUGHAGE LEVEL ON EFFICIENCY OF GROWTH AND MUSCLE DEPOSITION IN BULLS AND STEERS
Authors: JONES S. D. M. , PRICE M. A. , BERG R. T. , HARDIN R. T.
Published: March 2010

Bulls and implanted steers fed three dietary roughage levels (20% 50%, and 80% alfalfa-brome hay) were compared for various measures of efficiency in beef production. Cattle were about 1 yr of age at the start of the trial and bulls were heavier than steers (290 kg vs. 269 kg). There were four pens, each containing three cattle in every sex × dietary roughage combination. Animals in a pen were slaughtered when pen means approximated 450 kg or 580 kg. Increasing the level of roughage in the diet (20% to 80%) resulted in a significant decrease (P < 0.05) in both daily gain and liveweight gain per 100 MJ DE. The 50% roughage diet produced intermediate results. At a constant liveweight there was no significant (P < 0.05) effect of dietary roughage level on carcass muscle. Bulls produced 9% more muscle than steers at a constant liveweight. Muscle gain per 100 MJ DE decreased significantly (P < 0.05) with roughage level, and was higher for bulls than steers. For a constant amount of feed energy (24 148 MJ DE) bulls fed the 20% roughage diets produced 26.8 kg more carcass muscle (P < 0.05) than bulls fed the 80% roughage diet. Similarly, steers fed the 20% roughage diet produced 16.1 kg more carcass muscle (P < 0.05) than steers fed the 80% roughage diet. Bulls produced 23% more muscle than steers for a constant digestible energy intake (24 148 MJ DE). The overall results thus indicate that dietary roughage and sex-type cause large differences in the amount of carcass muscle produced for a constant energy intake.
ESTIMATED WATER AND FORAGE INTAKES IN NURSING RANGE CALVES
Authors: BAILEY C. B. , LAWSON J. E.
Published: March 2010

The intakes of water and forage dry matter by Angus calves on range before weaning were estimated from total water intake, milk intake, and digestible energy (DE) requirement. Water intake, including that in milk, as estimated by injection of tritiated water, rose from 8.3 kg/day at 44 days of age to 17.5 kg/day at 114 days and then fell to 13.7 kg/day at weaning. Milk supplied 90% of the water at 44 days and 25% at weaning. About 600 kg of free water would have been consumed over the pre-weaning period. Milk supplied 86% of DE intake at 44 days of age and 19% at weaning. Over this period, the forage dry matter intake, estimated from the difference between DE requirement and DE obtained from milk, rose from 0.5 kg/day to 5.5 kg/day and an estimated 450 kg would have been consumed between birth and weaning. Water intake per unit forage dry matter intake fell below 3.5 in late August or early September at which time siliceous urinary calculi could begin to form. Plant fiber residues in feces of calves increased as a consequence of the increasing forage intake and declining milk intake. It is suggested that the fiber content of feces could be used as an index of the relative importance of grass and milk in the nutrition of nursing calves on different types of range.
THE EFFECT OF SODIUM BICARBONATE, CEMENT KILN DUST AND AMMONIUM PERCHLORATE ON THE GROWTH OF LAMBS
Authors: BUSH R. S. , NICHOLSON J. W. G. , McINTYRE T. M. , CALDER F. W.
Published: March 2010

Two experiments were conducted in which 20-kg feeder lambs were fed diets supplemented with sodium bicarbonate, cement kiln dust or ammonium perchlorate, or control diet in combination with long timothy hay until they reached a market weight of 40 kg. Lambs fed sodium bicarbonate or cement kiln dust grew faster (P < 0.05) than the control group and showed equal or superior feed efficiency. Cement kiln dust in the diet produced a higher fecal pH (P < 0.01) thus demonstrating a buffering effect in the lower digestive tract. Sodium bicarbonate or cement kiln dust had no effect on rumen pH. The control and ammonium perchlorate groups grew at the same rate but the control animals showed better feed efficiency.
SELF-SELECTION OF SALT BY GILTS DURING PREGNANCY AND LACTATION
Authors: FRIEND D. W. , WOLYNETZ M. S.
Published: March 2010

There were two feeding experiments, in which feed was available free choice with 18 gilts in the first and 14 gilts in the second, and a metabolism trial, in which feed was restricted, with two pairs of gilts. Equal numbers of pregnant (P) and non-pregnant (NP) gilts were used; the terms "farrow" and "lactation" were applied to the NP gilts on a time basis only. In the first experiment and the 16-wk metabolism trial, a salt-deficient diet was fed, but in the second experiment the diet contained 0.5% added salt; all gilts had access to both water and a 0.5% salt solution. Considerable variation among gilts in both water and salt solution intake was evident, and there seemed to be a response to a taste preference rather than to a dietary need. During lactation, the intakes of salt solution and of total salt by the P gilts were approximately twice that of the NP gilts. Although consuming 78% more sodium from the salt solution, the P gilts did not lose in the feces and urine much more sodium than did the NP gilts; therefore, with equal feed intake, sodium retention appeared greater in the P gilts.
EFFECTS OF DIETARY PROPIONIC ACID ON SERUM LIPIDS AND LIPOPROTEINS OF PIGS FED DIETS SUPPLEMENTED WITH SOYBEAN MEAL OR CANOLA MEAL
Authors: THACKER P. A. , BOWLAND J. P.
Published: March 2010

Sixty-four crossbred pigs averaging 24 kg liveweight at allotment were used to study the effects of dietary propionic acid (PA) on cholesterol metabolism. Isonitrogenous and isoenergetic diets were based on either barley-soybean meal or barley-canola meal and contained either 0, 3, 6 or 9% PA. Inclusion of PA significantly reduced the levels of total serum cholesterol, associated entirely with a reduction in the high density lipoprotein fraction. There was a slight increase in the lipid content of both hearts and livers due to PA inclusion; hearts showed slight elevations in triglycerides, and livers had slightly elevated cholesterol and phospholipid levels. Pigs fed diets supplemented with soybean meal had lower levels of serum calcium, higher serum urea nitrogen, lower total serum cholesterol, lower low density lipoprotein cholesterol and lower circulating triglycerides compared with those fed canola meal. Hearts from pigs fed soybean meal appeared to have higher levels of total lipid, indicated by increases in triglycerides and phospholipids. There were no differences in lipid composition of livers due to source of protein supplement.
HATCHABILITY OF EGGS AND PERFORMANCE OF SCWL AND BROILER BREEDER HENS FED SOYBEAN MEAL AND FABABEAN MEAL DIETS
Authors: GARDINER E. E. , DUBETZ S.
Published: March 2010

Two experiments were conducted to determine the effects of feeding fababean meal diets to laying hens. Body weight, feed consumption, egg production, egg weight, eggshell strength, and hatchability of eggs were the parameters recorded. In exp. 1, where two types of hens (Single Comb White Leghorn (SCWL) and broiler breeders) were maintained in floor pens, hens fed a diet containing fababean meal had lower final body weights, lower average egg weight, and lower percentage hatchability of eggs than those fed soybean meal. Feed utilization, egg production, and eggshell strength were not significantly affected by diets. In exp. 2, in which SCWL were maintained in cages, hens fed diets containing 29.75% fababean meal required more feed per dozen eggs, had lower egg weights and had lower percentage hatchability than hens fed diets containing 7.20% soybean meal. Body weights, feed per bird per day, egg production, and eggshell strength were not significantly affected by diets. Supplemental dietary lysine improved feed conversion and percent hatchability of eggs for hens fed the fababean diets. The combined number of early dead chicks and infertile eggs was higher for eggs from the hens fed fababean meal diets than those fed soybean meal diets.
LIVE ANIMAL ULTRASONIC MEASUREMENTS OF SUBCUTANEOUS FAT THICKNESS AS PREDICTORS OF BEEF CARCASS COMPOSITION
Authors: TONG A. K. W. , NEWMAN J. A. , MARTIN A. H. , FREDEEN H. T.
Published: March 2010

Data on the total dissectible muscle and fat tissue from primal cuts of the left hindquarters of 356 crossbred steers and heifers, and from the entire left side of 98 Shorthorn steer carcasses were used to evaluate the usefulness of subcutaneous fat depth measurements between the 11th and 12th ribs for predicting carcass composition. Analyses revealed that the use of multiple fat depth measurements from different sites on one or both sides conferred no advantage over the use of the best single measurement. The major sources of variation in total weight of muscle and fat tissue from the crossbreds were breeding group, sex and weight. The residual variances remaining after adjustment for these sources of variation were significantly reduced (P < 0.05) by inclusion of a single fat measurement with reductions of 12.5% (muscle) and 22.0% (fat) provided by the carcass fat measurement and 7.1% (muscle) and 13.1% (fat) for the Krautkramer measurement. For the Shorthorn steers, line and weight were the major sources of variation and larger reductions in the residual variances (16.3% for muscle and 24.6% for fat) were obtained by inclusion of carcass fat in the model. The ultrasonic fat measurements were less effective than carcass fat and the Scanogram gave larger reductions in residual variance than the Krautkramer (e.g., 8.1 vs. 3.9% for weight of muscle tissue). The results of this study suggest that live animal ultrasonic measurements of subcutaneous rib fat depth can be used to achieve modest improvement in predictors of beef carcass composition.
EFFECT OF A SKIM MILK SUPPLEMENT ON GROWTH AND BODY COMPOSITION OF SUCKLED PIGS
Authors: SARKAR N. K. , ELLIOT J. I. , LODGE G. A.
Published: March 2010

Sows’ milk contains more fat than is required for optimal growth of the baby pig. The possibility of diverting this excess energy from deposition as fat to promotion of protein synthesis by providing a high protein-low fat skim milk supplement from 2 to 20 days of age during the suckling period was investigated. Pigs that received the milk supplement gained 12.5% more (P < 0.05) from 2 to 20 days of age than those reared exclusively on the sow and reached market weight (90 kg) 7 days earlier. At 35 days of age there was no significant difference (P > 0.05) in weight gain between the two treatment groups. Although no significant differences were found (P > 0.05) in carcass composition between the pigs of the two treatment groups, there seemed to be a slightly greater tendency, based on protein: ether extract ratio, for the pigs on the milk supplement to synthesize more protein than the pigs of the control group between 2 and 35 days of age. There was no significant difference in carcass composition at market weight.
GENETIC CHANGES IN MEAT-TYPE CHICKENS IN THE LAST TWENTY YEARS
Authors: CHAMBERS J. R. , GAVORA J. S. , FORTIN A.
Published: March 2010

Three experimental strains and two modern commercial stocks of meat-type chickens were compared in 1978. One experimental strain, K, an unselected control, represented broilers of 20 yr ago. A second experimental strain, A, selected for high broiler weight and a third, D, selected for high broiler and low adult weights had been derived from strain K and represented experimental strains genetically improved by artificial selection. All stocks were hatched and reared simultaneously using modern industrial practices. At 47 days, 70 birds of each sex and stock were slaughtered and the carcasses chemically analyzed. Also, 25 hens of each of strains A, D and K were slaughtered when 68 wk old and abdominal fat and carcass weight data were analyzed. The selection for higher broiler weight in strain A increased both broiler and adult body weights more and percent carcass fat less than the selection for high broiler and low adult weight in strain D. Relative to strain A, carcass weight of strain D was 10% lower in broilers and 16% lower in adult hens. Respective means for the modern commercial broilers, strain A broilers, and "broilers of 20 years ago" were 1552, 1001 and 676 g dressed carcass weight; 2.4, 1.6 and 1.4% abdominal fat; 17.2, 15.4 and 12.4% carcass fat (wet basis) and 1.90, 1.92 and 2.01 feed conversion. Thus, the modern broilers have a dramatically increased growth rate accompanied by higher fat content. The greater fat deposition may at least partly account for the lack of significant improvement in feed conversion.
COMPARISON OF SINGLE AND MULTIPLE TRAIT BEEF SIRE EVALUATIONS
Authors: SCHAEFFER L. R. , WILTON J. W.
Published: March 2010

Beef bulls of 13 breeds were evaluated from progeny records for calving ease, weaning weight and yearling weight using single and multiple trait best linear unbiased prediction techniques. Multiple trait procedures allowed more bulls to be evaluated for all traits and gave slightly greater variances to sire evaluations than the single trait method. The correlations of proofs between single and multiple trait methods were above 0.9 for the majority of the breeds for each trait, with the lowest correlations being between yearling weight proofs from the two methods. The correlations of proofs between traits within the multiple trait analysis were greater in absolute magnitude than within the single trait analyses. Multiple-trait procedures seem to be advantageous for lowering the standard errors of prediction for young bulls with their first proof, and for removing the effects of selection for weaning weight from the yearling weight proofs.
EFFECT OF HIGH CONCENTRATE FEEDING ON THE CARCASS QUALITY AND FAT COLORATION OF GRASS-REARED STEERS
Authors: FORREST R. J.
Published: March 2010

Fifty yearling beef steers of primarily mixed British beef breeding, and averaging 237.8 kg (SD = 23.47) were reared on grass from April to October. They were then placed in a feedlot for finishing and serially slaughtered over a 112-day feeding period. Feedlot gains averaged 0.64 kg/day, while carcass weight increased from 380.8 to 450.2 kg and rib fat increased from 18.7 to 30.8%. After 56 days in the feedlot, all carcasses graded either A-1 or A-2. After 28 days, the amber fat color, as scored by Federal Government graders, had been reduced from 6.5 to 4.5 when rated on a scale ranging from 1 (white) to 9 (intense amber). Carotene analysis of the carcass fat demonstrated a significant reduction (P < 0.05) from 0.28 to 0.17 mg/100 g fat during the first 28-day feeding period. These findings indicate that yearling steers reared on grass and not carrying an excessive amount of subcutaneous fat can produce A-1 carcasses, with acceptable coloration, after a concentrate feedlot finishing period of 56 days.
THE EFFECT OF GRAIN FEEDING ON THE EATING QUALITY OF BEEF FROM CULLED COWS
Authors: HAWRYSH Z. J. , PRICE M. A.
Published: March 2010

The cooking and eating quality characteristics of rib-eye roasts obtained from cows after removal from the breeding herd and after 8 or 16 wk of realimentation were determined. Evaluations of the effects of maturity class (physiological age) and external fatness on meat quality were also made. Cooking losses from roasts were affected by maturity class, external fat "cover" and realimentation. The percentage of fat in raw muscle samples representing maturity classes II (intermediate) and III (mature) was similar and significantly higher than that of comparable maturity class I (youthful) samples. There were significant differences in percent fat due to realimentation. Trained panelists determined significant effects of maturity on tenderness, amount of connective tissue and amount of fat. Water-holding capacity data for roasts from maturity classes I and II were similar and significantly higher than comparable samples from maturity class III animals. However, objective measurements of tenderness, softness and color for roasts showed no differences due to maturity class. All palatability traits evaluated subjectively and objectively in roasts show no significant effects of either external fat or realimentation. Thus these studies suggest that rib-eyes obtained from culled cows with or without realimentation may be acceptable to Canadian consumers as a retail cut.
THE FEEDLOT PERFORMANCE AND CARCASS COMPOSITION OF YOUNG AND MATURE CULL HOLSTEIN COWS
Authors: JONES S. D. M. , MACLEOD G. K.
Published: March 2010

Twelve young and twelve mature lean Holstein cows were fed a high energy diet to appetite based on high moisture corn and haylage. In addition to the cows put on feed, six young and six mature cows were slaughtered at the start of the trial to estimate initial body composition. After 68 days on feed, two young cows and two mature cows were slaughtered on a weekly basis until the conclusion of the trial. Mature cows were initially 45 kg (P < 0.5) heavier than young cows and this difference had increased to 57 kg at the conclusion of the trial. There were no significant differences between young and mature cows in average daily gain (1.37 vs. 1.48 kg/day) or dry matter feed conversion rate (8.46 vs. 8.31 kg DM/kg gain). Average daily dry matter intake was higher (P < 0.05) for mature cows than young cows. There was no decline in average daily gain during the feeding period, although dry matter feed conversion increased for both young and mature cows. There were few differences between young and mature cows slaughtered initially and those slaughtered after the feeding period in carcass composition, and the carcass characteristics that were measured. Young cows, however, had significantly (P < 0.5) higher carcass grades after a feeding period. The feeding period resulted in a decreased proportion of lean and bone and an increased proportion of fat in all the major fat depots (subcutaneous, intermuscular, body cavity fat).
CHRONIC COPPER TOXICITY IN LAMBS: A SURVEY OF BLOOD CONSTITUENT RESPONSES
Authors: BUCKLEY W. T. , TAIT R. M.
Published: March 2010

Blood chemistry of lambs was studied during the period of liver copper accumulation in chronic copper toxicity. In trial 1, dietary copper was 10.9, 17.8 and 25.2 mg/kg. During a 10-wk feeding trial no mortalities due to copper toxicity and no differences in growth rate were found (P > 0.05). At slaughter, liver copper levels were 239, 454 and 721 μg/g of dry matter, respectively (P < 0.05). There was no response to added dietary copper for hematocrit, ferroxidase, aspartate aminotransferase, allantoin, plasma protein, catalase, molybdenum or plasma copper (P > 0.05). In trial 2, dietary copper was 9.1 and 37.3 mg/kg. Lambs were individually fed for an 11-wk feeding trial. No mortalities or difference in growth occurred (P > 0.05). At slaughter, liver copper levels were 372 and 1109 μg/g of dry matter, respectively (P < 0.05). Plasma aspartate aminotransferase was elevated in response to added dietary copper (P < 0.05). No effect due to added dietary copper was found with superoxide dismutase, alkaline phosphatase, ferroxidase, lactate dehydrogenase, plasma protein, hemoglobin, plasma copper, calcium, inorganic phosphate, cholesterol, triglyceride, uric acid, urea nitrogen or hematocrit (P > 0.05). Only plasma aspartate aminotransferase and liver copper concentration could be considered useful indicators of high copper status.
THE EFFECTS OF THE LEVEL OF IODINE IN CANOLA MEAL CONCENTRATE ON MILK IODINE AND THIOCYANATE CONTENT AND THYROID FUNCTION IN DAIRY COWS
Authors: LAARVELD B. , CHRISTENSEN D. A. , BROCKMAN R. P.
Published: March 2010

Six lactating heifers were used in a randomized block design to measure the effects of different levels of iodine supplementation in a canola meal (CM) based concentrate on milk iodine and thiocyanate content and thyroid function. The treatments were a pre-experimental control diet (diet C) and a concentrate containing 20% Tower CM (air-dry) with 1.2 (CM-1.2), 2.2 (CM-2.2), 3.3 (CM-3.3) and 4.5 (CM-4.5) mg supplemented iodine/kg concentrate dry matter. The same roughage mixture was fed with all diets. Cows were maintained on diet CM-1.2 for 5 wk, after which they were changed sequentially to diets CM-2.2, CM-3.3 and CM-4.5 at 3-wk intervals. Milk samples were taken and a thyrotropin-releasing hormone test was conducted before the start of the experiment and at the end of each period. Milk samples were also taken daily between days 2 and 6 after diet change-over during treatments CM-2.2, CM-3.3 and CM-4.5. Concentrations of iodide in milk (mean ± SE) for diets C, CM-1.2, CM-2.2, CM-3.3 and CM-4.5 were 42.0 ± 10.9, 9.2 ± 0.4, 11.1 ± 0.3, 14.5 ± 1.0 and 18.7 ± 1.2 μg/100 mL, respectively. Milk iodide content for the CM concentrate with different iodine levels was lower (P < 0.01) than the pre-experimental control value. However, diets CM-3.3 and CM-4.5 successively increased (P < 0.05) milk iodide content compared to diets CM-1.2 and CM-2.2. During the adaptation periods of diets CM-3.3 and CM-4.5, milk iodide content increased (P < 0.05) rapidly compared to the previous treatment mean. Milk thiocyanate concentrations for the CM-1.2, CM-2.2, CM-3.3 and CM-4.5 diets were 134.8 ± 4.6, 135.3 ± 7.4, 117.3 ± 5.0, and 156.0 ± 6.7 μmoles/L, respectively. Thyroid function of the cows was not different among the different diets, being influenced by neither the CM nor level of iodine. Iodine supplementation of CM based concentrate at 3.3 and 4.5 mg/kg concentrate DM increased milk iodide concentrations, but not to pre-experimental levels. Milk iodide concentrations were normal during any treatment.
TOXICITY AND METABOLIC EFFECTS OF INTRAVENOUSLY ADMINISTERED 3-NITROPROPANOL IN CATTLE
Authors: MAJAK W. , McDIARMID R. E. , UDENBERG T. , DOUWES H.
Published: March 2010

In vitro and in vivo metabolic studies were conducted with bovine blood to determine decay rates for 3-nitropropanol (NPOH), a toxic forage constituent occurring in many Astragalus species. Methemoglobin (metHb) and plasma nitrite [Formula: see text] levels were concomitantly determined and early signs of poisoning were recorded. Subtle increases in heart and respiration rates, development of a placid, stupefied state, frothy salivation and incoordination characterized early stages of intoxication. Animals with low decay rates for NPOH showed a gradual increase in the metHb and [Formula: see text]. When the decay rate was high, a rapid increase in netHb and [Formula: see text] was observed. Acutely poisoned animals showed the highest levels of metHb and [Formula: see text] but intermediate rates of decay for NPOH. When NPOH was incubated with bovine blood in vitro, [Formula: see text] was not detected and metHb was not significantly altered, indicating that NPOH is not metabolized in bovine blood. A new method is described for determining NPOH in bovine blood.
DIGESTIBILITY AND VOLUNTARY INTAKE BY WETHERS OF DIETS CONTAINING AMMONIATED OR HIGH-PRESSURE STEAM-TREATED NEEPAWA WHEAT STRAW FROM FIELDS FERTILIZED WITH MANURE OR CHEMICAL FERTILIZER
Authors: KNIPFEL J. E. , KERNAN J. A. , COXWORTH E.
Published: March 2010

High-pressure steam treatment and ammoniation were compared as procedures to improve the intake and digestibility of Neepawa wheat straw by wethers. In addition, the effects of hog manure or commercial fertilizer upon the nutritional value of Neepawa wheat straw were examined. Ammoniation increased the availability of energy and N of diets containing straw from both fertilizer treatments. Straw from the manured field was of slightly higher quality before and after ammoniation than was straw from the chemically fertilized field. High-pressure steam treatment increased the digestibility of energy-yielding components of diets containing chemically fertilized straw more than ammoniation, and increased intake of digestibile energy to levels significantly greater than those of untreated or ammoniated straw. In vitro forage evaluation consistently underestimated the nutrititive value of rations containing high levels of either untreated or processed straw.
THE EFFECT OF PROTEOLYTIC ENZYME AND VITAMIN-MINERAL SUPPLEMENTATION OF A SOY PROTEIN MILK REPLACER ON CALF PERFORMANCE AND NUTRIENT DIGESTIBILITY
Authors: HOOPER G. S. , WHEELER E. ELIZABETH , STONE J. B. , WITTY R.
Published: March 2010

Fifty-six newborn Holstein bull calves were fed a milk replacer containing 20% of protein from milk sources and 80% of protein from a soy isolate (Promine-F). Eight treatments were designed (seven calves per treatment) in a 4 (enzyme) by 2 (cofactor) experiment to investigate the effect of addition of four levels of proteolytic enzyme (0.0, 1.1, 2.2 or 4.4 million Delft Units (DU) per kilogram of milk replacer) and the presence or absence of a vitamin-mineral supplement (+ or − cofactor). Intake of dry matter from milk replacer or calf starter was not affected by enzyme level or cofactor addition. An increase in the level of enzyme resulted in a reduced rate of gain by calves during the preweaning (4–42 days) and postweaning (42–56 days) periods. Digestibility of dry matter and protein was improved when low levels of enzyme were fed (1.1 and 2.2 million DU/kg) in comparison to when no enzyme or the highest level of enzyme (4.4 million DU/kg) was fed. Addition of the cofactor supplement resulted in an improvement in rate of gain and nutrient digestibilities in comparison to the same ration containing no cofactor.
NUTRITIONAL EVALUATION OF MEALS AND MEAL FRACTIONS DERIVED FROM RAPE AND MUSTARD SEED
Authors: SARWAR G. , BELL J. M. , SHARBY T. F. , JONES J. D.
Published: March 2010

Low glucosinolate rapeseed meal (RSM) (B. napus 'Bronowski'), rapeseed meal fractions (hulls, detailed meal, dehulled and water-washed meal, lyophilized water extract) derived from Bronowski and from a high glucosinolate rapeseed (B. napus 'Oro'), yellow mustard (B. hirta) hulls and meal were subjected to chemical and nutritional evaluations. Oat hulls and soybean meal were included for comparison. Proximate, amino acid and glucosinolate analyses and feeding experiments were conducted. The processed meals, hulls and extracts were included in diets to provide 8, 12 and 16% dietary crude protein in conjunction with a purified basal fraction containing 5% casein. The toxic effects of glucosinolates fed with active myrosinase were confirmed. Glucosinolates included in soybean meal (SBM) control diets were innocuous. Removal of rapeseed hulls increased digestible (DE) and metabolizable energy (ME) and digestible crude protein contents, but the inclusion of the hulls in high energy, non-rapeseed meal (RSM) diets had no adverse effects on growth of mice or efficiency of feed utilization. Dehulled RSM had lower DE than SBM, partly due to lower digestibility of the non-hull, non-protein energy fraction. Dehulling increased the protein content of RSM, decreased the lysine content of the protein and improved the digestibility of protein. Protein quality tests (Protein Efficiency Ratio and Apparent Biological Value) showed protein of RSM to be equal to that of soybean meal.
EFFECT OF REARING DIET ON PERFORMANCE OF EARLY MATURING PULLETS
Authors: LEESON S. , SUMMERS J. D.
Published: March 2010

Leghorn chicks of a commercial strain were offered various feeding programs in an attempt to influence production and egg size of early maturing pullets. Feeding programs consisted of chick starter 0–8 wk, chick grower 8–15 wk; chick starter 0–8 wk, broiler starter 8–15 wk; broiler starter 0–8 wk, broiler grower 8–15 wk. Birds were housed either at 17 or 26 °C after initial brooding. Each treatment was represented by 10 cages of 10 birds each. After 7 days, 8 h of light at 10 lx intensity was provided daily. At 15 wk of age, birds were moved to laying cages (two birds per cage) and immediately subjected to a photoperiod of 14 h light. Birds were offered either a 17 or 20% crude protein (CP) diet. Rearing treatments and laying diets were arranged factorially, with each treatment represented by five replicate groups of four cages each. Conventional production parameters were measured throughout growth and a 36-wk laying period. Pullets fed broiler starter to 8 wk were heavier (P < 0.05) than birds fed chick starter, while regardless of diet, birds in the hot room were lighter (P < 0.05). At 15 wk, diet had no effect on body weight within the regular environment, while in the hot room birds fed broiler diets were significantly heavier (P < 0.05). Irrespective of diet, pullets consumed similar quantities of energy, but markedly different quantities of protein. In the first 28 days of egg production, birds reared on broiler diets produced more eggs (P < 0.05) of a heavier size (P < 0.05). These effects were not evident after this time and the magnitude of this early response was not of commercial significance. Egg production, shell quality, feed intake and mortaility were not influenced by rearing diet. Birds from the hot, rather than normal environment, consistently produced smaller eggs. It is concluded that high-protein, high-energy, broiler diets cannot by themselves be used successfully to induce early mature body size, and that the confounding factor for this is the pullets' voluntary limit to energy intake.
INFLUENCE OF FABABEAN FRACTIONS ON EGG WEIGHT AMONG LAYING HENS FED TEST DIETS FOR A SHORT TIME PERIOD
Authors: OLABORO G. , CAMPBELL L. D. , MARQUARDT R. R.
Published: March 2010

A short-term bioassay test using Single Comb White Leghorn (SCWL) laying hens was developed to study various fractions of fababeans, to determine the location of the egg-weight-depressing factor (EWDF), and to determine the effect of heat treatment on EWDF activity. A second objective of the research was to develop an extraction method to facilitate studies on identification and mode of action of the factor(s). The 14-day period proved useful in confirming that EWDF activity was concentrated in the cotyledon portion of fababean seeds and associated with the protein rather than the starch component. Ethanol-water extraction was effective in concentrating the factor.
RAM-INDUCED SYNCHRONIZATION OF ESTRUS IN CONFINED EWES UNDER CONTROLLED LIGHTING
Authors: MARCUS G. J. , HACKETT A. J. , ROBERTSON H. A.
Published: March 2010

Among totally confined ewes, the pattern of estrus occurrence after exposure to rams was similar to that produced by prostaglandin F2α-treatment, but differed from that occurring in ewes on pasture at the onset of the breeding season. The degree of synchronization of lambing was the same whether estrus was synchronized by rams or by prostaglandin, but no synchronization occurred among the ewes on pasture.
CHEMICAL CHARACTERIZATION AND FEEDING VALUE OF APOLL RADISH SEED SCREENINGS FOR CHICKS
Authors: SHEN HUILE , LEESON S. , SUMMERS J. D.
Published: March 2010

Proximate amino acid, fatty acid and mineral analyses of radish seed screenings were undertaken to ascertain potential as a feedstuff. Apart from the screenings containing about 3% erucic acid, no other deleterious constituents were observed. The product was found to have a metabolizable energy content of 18.13 MJ/kg, and broiler performance to 21 days was not affected when diets contained up to 5% of this ingredient.
MILK PRODUCTION AND WEIGHT OF COWS OF THE HEREFORD AND HIGHLAND BREEDS AND THEIR RECIPROCAL CROSSES
Authors: LAWSON J. E.
Published: March 2010

Highland, Hereford, Hereford × Highland, and Highland × Hereford dams were compared in a range of environment. At 12 mo, body weights of reciprocal cross heifers exceeded those of the Highland by 12.5%, and the Highland × Hereford surpassed the Hereford by 5.8%. Hereford and reciprocal cross cows exceeded the Highland by 15–20% at each of the bi-yearly weights between 18 and 60 mo. The 24-h milk yield of the Hereford × Highland (highest) exceeded that of the Highland (lowest) by 26, 35, and 40% in June, August, and October. Dam group means for percent milk fat did not differ and differences in percentages of SNF or protein were small. Rankings for weight of milk, fat, SNF, and protein over the last 21–22 wk of the lactation period were: Hereford × Highland = Highland × Hereford > Hereford > Highland. Highlands cannot be recommended for use as a pure breed under range conditions. However, in a first cross with the Hereford they restrict cow size and promote milk production and calf growth.
CHEMICAL COMPOSITION AND CARCASS SPECIFIC GRAVITY IN CATTLE: EFFECT OF LEVEL OF ENERGY INTAKE AND INFLUENCE OF BREED AND SEX
Authors: FORTIN A. , REID J. T. , SIMPFENDORFER S. , AYALA H. J. , ANRIQUE R. , KERTZ A. F. , MAIGA A. M. , SIM D. W. , WELLINGTON G. H.
Published: March 2010

Regression equations to predict the chemical composition of the carcass and empty body from carcass specific gravity were computed for Holstein and Angus cattle fed at two levels of energy (ad libitum or 65–70% of ad libitum). One hundred and forty-one Holstein and Angus bulls, steers and heifers were slaughtered at body weights ranging from 120 to 706 kg and at ages varying from 200 to 650 days. The specific gravity of the right side of the carcass and the chemical composition of the carcass and the empty body were determined. The linearities of the relationships between chemical composition and specific gravity were examined. Sex and breed did not influence (P > 0.05) the relationships between the water, ether extract and energy content of the carcass or empty body and specific gravity whereas the level of energy intake was found to have an effect (P < 0.01). The relationships between the percentage of empty body protein and specific gravity was influenced (P < 0.01) by sex and breed but was not altered (P > 0.05) by the level of energy intake. Relationships between composition and specific gravity were computed using animals containing a minimum of 12% ether extract in the carcass. However, the removal of the leaner animals did not markedly improve (in terms of residual standard error) the precision of prediction of carcass and empty body composition from specific gravity. It was suggested that carcass specific gravity be used to estimate the carcass and empty body composition of groups of animals rather than of individual animals.
COMPARISON OF NATURAL MATING AND ARTIFICIAL INSEMINATION ON REPRODUCTIVE PERFORMANCE OF THREE STRAINS OF SHEEP HOUSED IN TOTAL CONFINEMENT
Authors: HACKETT A. J. , WOLYNETZ M. S.
Published: March 2010

The reproductive performance (fertility, prolificacy and fecundity) of confined sheep was measured following natural mating or artificial insemination (AI) with 0.1 mL of unextended semen collected by artificial vagina or by electroejaculation. The estrous cycles of the ewes were synchronized in late summer using intravaginal sponges impregnated with fluorogestone acetate. Pregnant mares' serum gonadotrophin (PMSG) was administered intramuscularly to approximately half of the ewes. There was no significant difference in the reproductive performance of ewes bred by natural mating (45%) or AI (30%) or between the two methods of semen collection (30 vs. 29%). Fertility was greater (P < 0.05) in ewes treated with PMSG (33 vs. 11%) mainly because of a tendency for higher fertility in ewes bred by AI. PMSG also significantly (P < 0.01) increased prolificacy and fecundity, 1.8 vs. 1.5 and 58 vs. 16%, respectively.
PLASMA GLUCOSE, LACTATE AND FREE FATTY ACID RESPONSES TO ADRENALINE IN CHRONICALLY WARM- AND COLD-EXPOSED SHEEP
Authors: GRAHAM A. D. , PHILLIPS G. D.
Published: March 2010

The effects of chronic cold exposure, fasting, or both on the plasma metabolite responses to jugular infusions of adrenaline were studied in eight five-mo-old wether lambs. Following maintenance at 20–22 °C or −4 to 10 °C for 2–3 wk the sheep received adrenaline infusions (0.15 μg∙kg−1∙min−1) for 75 min prior to and following a 72-h fast. Plasma samples collected at intervals of 10–15 min before and during adrenaline infusion were analyzed for glucose, lactate and total free fatty acids. Chronic cold exposure had no effect on the pre-infusion plasma glucose, lactate or free fatty acid concentrations. Fasting decreased plasma glucose and lactate and increased plasma free fatty acid concentrations. The plasma glucose response to adrenaline was greater (P < 0.01) in cold- than warm-exposed sheep and fasting depressed this response to a greater extent in the cold-exposed sheep. The plasma lactate response to adrenaline was not influenced by temperature treatment or fasting. Both groups of fasted sheep showed a large increase in plasma free fatty acids during adrenaline infusion but when fed the response was minimal.
NUTRITIONAL VALUE OF UNEXTRACTED AND EXTRACTED DEHULLED CANOLA RAPESEED FOR BROILER CHICKENS
Authors: SHIRES A. , BELL J. M. , BLAIR R. , BLAKE J. A. , FEDEC P. , McGREGOR D. I.
Published: March 2010

Two experiments were conducted with broiler chickens from 1 day old to 4 wk of age to determine the nutritional value of unextracted and extracted dehulled canola rapeseed (DCS). In exp. 1, raw or autoclaved DCS at levels of 10 and 20% of the diet were compared with extracted DCS at levels of 5 and 10%. The inclusion of extracted DCS in the diet had no adverse effects on the performance of chicks. Dietary levels of 10 and 20% raw DCS resulted in a decrease in feed intake (P > 0.05) and weight gain (P < 0.05) and an increase in feed/gain ratio (P < 0.05). The performance of birds fed autocalved DCS was intermediate between that of birds fed raw or extracted DCS. Experiment 2 involved a comparison of extracted DCS at levels of 0, 10, 20 and 30% of the diet with variable or constant levels of dietary lysine and sulphur amino acids. Dietary levels of 20 and 30% extracted DCS resulted in a progressive decrease (P < 0.001) in feed intake and weight gain, and an increase (P < 0.001) in feed/gain ratio. Lysine supplementation improved the nutritional value of extracted DCS. It was concluded that canola rapeseed should be heated before feeding to broiler chickens. Autoclaved or extracted DCS may be included in the diet of broiler chickens at levels of 10% with no reduction in growth rate.
DROP FARROWING AS AN AID TO SOW MANAGEMENT
Authors: FRIEND D. W. , ELLIOT J. I.
Published: March 2010

A modified farrowing crate allowed piglets at birth to drop 25 cm to a well-bedded, warmed box. Piglets were returned to the so w 10 h after the birth of the first. Seven litters were drop-farrowed and seven conventionally farrowed. Drop-farrowed piglets were significantly lighter at 10 h (P < 0.05) but not at 7 days of age.
THE FUTURE OF MEAT AS A SUSTAINABLE FOOD SYSTEM
Authors: BUCKLAND R. B.
Published: March 2010

The theme of this year's Canadian Society of Animal Science Symposium was chosen in conjunction with the Agricultural Institute of Canada who selected "Sustainable Food Systems" as the theme for their Conference. In discussing the future of meat as a sustainable food system, three areas have been selected for attention: (1) grading systems and their effectiveness in identifying superior carcasses; (2) the challenges in improving meat quality and how improvements with respect to growth rate in the areas of genetics, nutrition and management have affected meat quality; (3) the future consumption patterns of meat and how these will be affected by other changes that are taking place regarding our eating habits.In setting the background for these papers, I will briefly mention a few of the important trends that have taken place in Canada with respect to meat consumption over the past 17 years. I will not attempt to interpret these changes in this introduction. Total meat consumption, excluding fish (which averages about 2 kg/yr/capita) has increased from 76.2 kg per capita per year in 1963 to a high of 99.6 kg in 1976 with the value for 1980 being 97.4 kg. Beef consumption has followed quite closely the pattern of total meat consumption with the per capita consumption being 33.7 kg in 1963, rising to 51.4 kg in 1976, but then declining much more sharply than did total meat consumption to a figure of 39.9 kg in 1980. This drop in consumption of beef has been almost completely compensated for by increases in pork and broiler chicken consumption. Pork consumption was 23.0 kg per capita in 1963 and it changed very little, except for fluctuations, up until 1976 when the figure was 25.2 kg but, since then, it has increased rapidly to an all-time high figure of 32.4 kg in 1980 which may be a cycle peak, a new trend or a combination of both. Over the years, broiler chicken meat has seen the greatest increase in consumption going from 8.9 kg per capita in 1963 to 14.6 kg in 1976 and for 1980, the figure is 17.3 kg. Veal consumption has declined from about 3 kg per capita in 1963 to 1.4 kg in 1980 with mutton and lamb showing a similar decline from just under 2 kg in 1963 to 0.8 kg in 1980. Turkey consumption has held relatively steady at about 4 kg per capita while fowl consumption showed a decline from about 2 kg in 1963 to 1.3 kg in 1980.
THE CHALLENGES OF IMPROVING MEAT QUALITY
Authors: SWATLAND H. J.
Published: March 2010

The most urgent challenge to improve meat quality in Canada at the present time is to attack the many causes of meat quality spoilage which exist in production, transport and slaughter methods. These factors operate through muscle metabolism. Rapid production of large amounts of lactate after slaughter causes pale meat with a high water loss. Inadequate lactate formation causes dark meat which appears dry because its water is tightly bound. These conditions are related to animal stress due to poor husbandry, transport and slaughter methods, but the susceptibility to stress is heritable. Key words: Meat quality, postmortem metabolism, muscle structure
ENVIRONMENTAL AND GENETIC EFFECTS ON PREWEANING PERFORMANCE OF CALVES FROM FIRST-CROSS COWS. I. CALVING EASE AND PREWEANING MORTALITY
Authors: FREDEEN H. T. , WEISS G. M. , NEWMAN J. A. , RAHNEFELD G. W. , LAWSON J. E.
Published: March 2010

Calving ease and calf mortality were studied for 4034 calves produced in second and later parities at two locations, Brandon and Manyberries, by contemporary populations of first-cross dams mated to four terminal sire breeds, Charolais (C), Chianina (Chi), Limousin (L) and Simmental (S). The dams represented 10 F1 crosses, the Hereford × Angus (HA) and nine crosses produced by mating C, L and S Bulls with Hereford, Angus and Shorthorn cows. Calving difficulty and mortality were higher among males (P < 0.0001) than females. Calving ease was not influenced by location, but postnatal mortality, particularly of males, was substantially less at Brandon (P < 0.0001). Differences in calving ease among terminal sire progeny groups were not significant when the four breeds were mated to HA dams, but all paired or three-way comparisons involving the Limousin indicated the highest proportion of unassisted births (P < 0.0001) and the lowest incidence of difficult births (P < 0.006) for this sire breed. Terminal sire differences in postnatal mortality were not present among progeny from the HA dams, nor were they observed in the paired comparisons involving progeny of the Chi vs. those of the other three terminal sire breeds. For this trait, however, the paired comparisons among progeny from C, S and L sires indicated a ranking of C > S > L (P < 0.04). Breed of dam's dam (Hereford, Angus, Shorthorn) had no influence of calving ease or mortality, but breed of dam's sire (C, L, S) was important with progeny from L-sired dams having the highest incidence of unassisted births (P < 0.01) and the highest incidence of postnatal mortality (P < 0.06). The proportion of unassisted births increased as the experiment progressed (P < 0.001) and may have been associated with advancing age of the dams. There was, however, a large location × year interaction for this trait (P < 0.002) with Manyberries recording substantially greater calving difficulty than Brandon during the first 3 yr. Interactions involving calf sex, year of birth, breed of terminal sire and location were identified for calving ease. Calf mortality generally increased with increasing calving difficulty but the relationship between calving ease and mortality was influenced by the degree of precalving environmental stress on the dam. Key words: Beef cattle, crossbreeding, calving ease, mortality