bluuebunny/crossref_metadata_2025 huggingface dataset:
EFFECT OF ALTERING THE RUMEN LOAD ON THE FEEDING BEHAVIOR IN SHEEP
Authors: HIDARI H.
Published: March 2010

Fistula feeding before a morning meal increased rumen load and suppressed feeding of the sheep. The removal of food residues from the rumen decreased rumen load and stimulated subsequent feeding. The rumen load, estimated from the torque values of rumen content, seems to affect the tension receptor in the rumen. Key words: Sheep, rumen load, rumen digesta, food intake
RUMEN DIGESTA LOAD IN RELATION TO VOLUNTARY FEED CONSUMPTION AND RUMINATION IN ROUGHAGE-FED YOUNG SHEEP
Authors: WESTON R. H.
Published: March 2010

Rumen digesta load was inversely related to estimated net energy intake and positively related to time spent in ruminating and bolus chewing duration in young sheep fed medium and low quality roughage diets; an interplay between rumen transactions and energy metabolism in roughage intake regulation is suggested. Key words: Roughage intake, rumen digesta, rumination, young sheep
SITES OF ORGANIC MATTER AND PROTEIN DIGESTION IN LACTATING COWS FED FRESH GRASS FROM SPRING TO AUTUMN
Authors: VERITE R. , JOURNET M. , REMOND B.
Published: March 2010

Broad seasonal variations in duodenal NAN flow were observed with lactating cows fed fresh ryegrass. Lower values were observed during summer when rumen ammonia might have been limiting and during autumn when protein degradability was likely high. Key words: Protein digestion, fresh grass, dairy cows, seasonal variations
EFFECTS OF SUPPLEMENTATION WITH SILAGE ON FORAGE INTAKE AND KINETICS OF DIGESTA FLOW OF CATTLE ON PASTURE
Authors: HORN G. W. , FORD M. J. , PHILLIPS W. A.
Published: March 2010

Effects of increasing silage intakes by growing cattle grazing wheat and bermudagrass pastures on forage intake, flow, turnover, fill and fecal output were studied. Increasing intakes of silage increased flow of wheat forage and appeared to have associative effects on wheat forage intake, whereas intake of bermudagrass decreased linearly as silage intake increased. Key words: Forage intake, grazing cattle, silage
A CONTROLLED RELEASE INTRARUMINAL DEVICE FOR THE ADMINISTRATION OF FECAL DRY-MATTER MARKERS TO THE GRAZING RUMINANT
Authors: LABY R. H. , KAUTZNER B. , GRAHAM C. A. , EDWARDS S. R.
Published: March 2010

A general purpose controlled release (CR) intra-ruminal device (CRD) containing chromium sesquioxide (Cr2O3) was used to measure mean daily fecal dry matter excretion (FE). The FE of penned sheep, estimated using the CRD, was 1.02 ± 0.04 of actual FE, independent of diet. A single, uniform release rate for the CRD was observed in grazing and penned sheep. Key words: Controlled release, fecal marker, chromic oxide
REDUCTION IN PARTICLE SIZE DURING RUMINATION IN CATTLE
Authors: CHAP K. , MILLIGAN L. P. , KENNEDY P. M.
Published: March 2010

Measurements of chewing behavior and of large particle breakdown during rumination were made with two steers given chaffed alfalfa or brome grass once daily for 4 h. Large particle content of boli retained in the mouth for chewing was enhanced by 38% compared to that in the regurgitated bolus, since some small particles were swallowed immediately with fluid. 58–75% of this coarse material was reduced to small particles by rumination. Specific fragility of both roughages was doubled at 16 vs. 4 h after feeding. Key words: Rumination, chewing, cattle
CONTROL OF THE MIGRATING MYOELECTRIC COMPLEX IN SHEEP
Authors: RAYNER D. V. , GREGORY P. C. , WENHAM G.
Published: March 2010

Chronically vagotomized sheep exhibit a normal MMC pattern but with slower propagation through the intestine. However, vagotomy abolishes premature MMCs induced by duodenal acidification, and initially greatly increases the frequency of the MMC. This suggests that both the CNS and intrinsic nerves are normally involved in control of the MMC. Key words: Sheep, migrating myoelectric complex, vagus nerve
CONTROL OF RUMEN TURNOVER IN NORTHERN RUMINANTS
Authors: WHITE R. G. , HOLLEMAN D. F. , SCHWARTZ C. C. , FRANZMAN A. W. , REGELIN W. L.
Published: March 2010

Turnover of liquid and solid components in the rumen of reindeer and muskox fed high-quality diets change markedly in relation to intake on a seasonal basis. In moose variable intake induced by digestibility differences caused changes in rumen turnover similar to those induced by seasonal effects in the reindeer and muskoxen. Key words: Northern ruminants, rumen turnover, seasonal food intake
GROWTH, PRODUCTION AND REPRODUCTION CHARACTERISTICS OF THE CANADIAN BREED OF CATTLE AND ITS FIRST CROSS AND BACKCROSS WITH BROWN SWISS. II. PRODUCTION AND REPRODUCTION
Authors: RONY DOMINIQUE D. , FAHMY MOHAMED H. , HOLTMANN WILFRIED B.
Published: March 2010

Milk and fat production, number of inseminations per conception, age and weight at calving and kilograms of calf born were studied on 21 Canadian (C); 25, 3/4C 1/4 Brown Swiss (3/4C) and 22, 1/2C 1/2 Brown Swiss (1/2C) cows raised at the Deschambault station and 20 cows each of C and 1/2C raised at the La Pocatiere Station. The cows were born between 1973 and 1977 and producted from 1975 to 1981 inclusive. Average 305-day milk production for the first two lactations was 4746 kg for 1/2C, 18% higher than 3/4C and 29% higher than C cows at Deschambault and 26% higher than C cows at La Pocatiere (P < 0.01). At Deschambault, fat percentage was 4.8% in C cows, 8 and 4% higher (P > 0.05) than in 1/2C and 3/4C cows, respectively. However, at La Pocatiere, fat percentage was similar in the C and 1/2C groups. In the 3/4C and 1/2C crosses at Deschambault, milk production increased 14.5 and 16.4% in second and a further 7.8 and 12.3% in third lactations. For C cows, the increase was 11.6 and 7.6% at Deschambault and 16.7 and 14.6% at La Pocatiere, respectively. C cows needed 0.23 and 0.34 less inseminations than 1/2C at Deschambault and La Pocatiere, respectively (P > 0.05). Twinning rate was 2.6, 2.8 and 6.2% for C, 3/4C and 1/2C cows, respectively. The higher twinning rate of 1/2C cows and a 1.6 kg heavier calves they produced resulted in an average of 2.3 kg more calves born than from C cows. The 1/2C cows were 23 and 31 days younger (P > 0.05) and 10 and 12% heavier (P < 0.01) at calving than C cows at Deschambault and La Pocatiere, respectively. The 3/4C cows were intermediate. There were significant differences between Deschambault and La Pocatiere stations, the performance at the former station being better. Lactation number and season of calving had significant effects on milk production. Key words: Canadian cattle, crossing with Brown Swiss, milk and fat production, reproduction
THE SENSITIVTY OF A TWO-TRAIT SELECTION INDEX TO CHANGES IN ECONOMIC WEIGHTS AND GENETIC PARAMETER ESTIMATES
Authors: ALLAN B. B. , WEISS G. M. , FREDEEN H. T.
Published: March 2010

Two-trait selection indexes comprising average daily gain (G) and adjusted average backfat depth (F) were constructed utilizing several permutations of economic and genetic parameters. In these permutations the ratio of economic weights employed (value per kg G: value per mm F) ranged from 5:1 to 75:1, the ratios of heritabilities (G:F) ranged from 0.625:1 to 1:1 and the genetic and phenotypic correlations ranged from zero to 0.25. The relative merits of these indexes were evaluated by comparing the expected genetic merit of progeny produced by the top 10% of the boars identified by each index as applied to a population of 590 boars station tested under the Canadian Record of Performance (ROP) system. Responses were estimated for each component trait (G,F), for feed conversion (FC) and the aggregate genetic response (G + F + FC) in standard deviation units. The net economic value of the aggregate genetic response was calculated as the sum of the values of the genetic responses for the individual traits weighted by their economic values. Variation in the economic and genetic parameters influenced the expected genetic response for the component traits but the aggregate response and its economic value varied little over the range of parameters employed. Indeed, an index constructed from estimates of the actual genetic, phenotypic and economic parameters gave net returns that were only $0.04 per hog greater than an index based on equal economic weights, equal heritabilities and zero correlations. This index, of course, is the simple phenotypic index which leads to the conclusion that results of selection based on a phenotypic index will be fully comparable to those of a highly sophisticated genotypic index. Key words: Selection index sensitivity to parameter variation, genotypic selection index, phenotypic selection index, effectiveness of index selection
GENETIC AND PHENOTYPIC PARAMETERS OF EARLY GROWTH TRAITS OF LAMBS REARED ARTIFICIALLY IN A CONTROLLED ENVIRONMENT
Authors: SHRESTHA J. N. B. , HEANEY D. P.
Published: March 2010

This study involved body weights of 6078 lambs from 525 sires of two synthetic dam strains developed at the Animal Research Centre with 50% Finnish Landrace background. Breeding was practiced in flocks A and B for lambing at 4-mo intervals under an 8-mo breeding cycle. Lambs were housed indoors in a controlled environment on expanded metal floors in windowless barns, reared artificially with milk replacer and solid diet from birth to weaning at 21 days of age. Thereafter, all lambs were fed solid diet to 70 days of age. Paternal half-sib estimates of heritability for lamb weights at birth, weaning, 49 and 70 days of age were 0.25–0.26. Heritability estimates in the two synthetic dam strains were in close agreement (P > 0.05). Genetic and phenotypic parameter estimates did not demonstrate any significant linear trends across lambing periods. The moderate levels of heritability estimates for lambs reared artificially under a controlled environment suggest that genetic response to selection could be enhanced by selecting lambs independent of potential maternal effects and competition among litter mates for a fixed quantity of milk. Estimates of genetic and phenotypic correlations among various lamb weights ranged from 0.60 to 1.00, and from 0.51 to 0.93, respectively. Lamb weights having closer proximity in time showed higher correlations. Moderate to high genetic correlations between body weight of lambs at different ages indicated that selection for weight at one age should cause no adverse effects on body weight at other ages. Key words: Sheep, artificial rearing, lamb weights, heritability, genetic and phenotypic correlations
CARCASS QUALITY CHARACTERISTICS OF THREE-WAY CROSS BEEF CATTLE REARED AT TWO LOCATIONS
Authors: RAHNEFELD G. W. , CLIPLEF R. L. , MARTIN A. H.
Published: March 2010

Carcass quality characteristics of 3673 steers (M) and heifers (F) born over a 6-yr period (1973–1978) at Brandon, Manitoba (farm conditions) and Manyberries, Alberta (range conditions) were compared. The progeny produced were out of 10 specific F1 crosses of dams mated to bulls of the Charolais (C), Simmental (S), Limousin (L) and Chianina (Chi) breeds. Dam crosses included Hereford × Angus (HA) and crosses sired by C, S and L out of H, A and Shorthorn (N) dams. Calves weaned at Manyberries were fed and evaluated at Lacombe. Sex differences, at both locations, indicated F>M for Warner-Bratzler shear force. At Brandon, M>F for conformation score, F>M for firmness score and F>M for percentage protein. For Lacombe data, M>F for chemical fat percentage, F>M for water holding capacity and F>M for percentage moisture. Terminal sire breed differences in the paired comparisons involving progeny of Chi (the comparisons with maximum degrees of freedom) indicated Chi progeny to have the highest color scores (darker cherry red) and C progeny the lowest (lighter cherry red), Chi progeny the lowest percentage chemical fat and C the highest, and Chi progeny the highest percentage moisture and C the lowest at both locations. At Brandon, the progeny ranking for Warner-Bratzler shear force was S>Chi>L, for pH Chi>S = L, for texture score Chi>C = S = L and Chi progeny had the lowest conformation scores and L progeny the highest. At Lacombe, significant progeny differences were recorded for Warner-Bratzler shear force with Chi>L and for water retention capacity S>Chi. At Brandon, breed of sire of dam effects indicated the progeny from S-cross dams had the highest texture scores. Progeny from L-cross dams had the lowest percentage chemical fat, the lowest skeletal maturity scores, and the highest percentage moisture. Progeny from C-cross dams had the highest conformation scores. At Lacombe, progeny from S-cross dams had the highest Warner-Bratzler shear force. At both locations, progeny from dams of Shorthorn breeding had the highest marbling scores. Direct comparison of progeny from exotic cross dams vs. progeny from HA dams at both locations indicated that the progeny from HA dams had lower color scores (lighter cherry red), a lower percentage moisture, higher marbling scores and a higher percentage chemical fat. At Lacombe, the HA dams had progeny with lower Warner-Bratzler shear force. At Brandon, the progeny from the HA dams had lower texture scores, higher firmness scores, a lower percentage protein and generally had lower conformation scores. The differences found between breeds of terminal sire and breed cross of dam for the traits evaluated are not of any commercial consequence. Key words: Cattle, breeds, carcass, quality
EFFECTS OF COLD EXPOSURE AND PLANT SPECIES ON FORAGE INTAKE, CHEWING BEHAVIOR AND DIGESTA PARTICLE SIZE IN SHEEP
Authors: CHAI K. , MILLIGAN L. P. , KENNEDY P. M. , MATHISON G. W.
Published: March 2010

Three closely shorn sheep were allotted to each of three diets of chopped hay prepared from red clover, reed canarygrass and bromegrass, respectively. The animals were housed at 25, 10 and −5 °C during three periods of 28 days. For the final 8 days of each period, each individual sheep was restricted to 90% of its voluntary feed consumption and hay was given at intervals of 2 h. Eating and chewing behavior, rumen fluid kinetics and digesta particle size were determined. Voluntary intake of clover hay was greater, but chews during eating and rumination were less than for sheep consuming grass hay. The small particle fractions present in the duodenum and rumination activity were greater in the sheep fed grasses. Feed intake, rumination chews and duration, and digesta particle size in the duodenum were increased in sheep housed at −5 °C. Eating duration and chews, particle size of rumen digesta and rumen fluid volume were not affected by cold stress, but fluid retention time was reduced, while daily fluid flow from the rumen tended to increase. Key words: Forage intake, cold stress, chewing behavior, digesta particle size, fluid passage
THE INFLUENCE OF THE SOW'S ADRENAL ACTIVITY ON THE ABILITY OF THE PIGLET TO ABSORB IgG FROM COLOSTRUM
Authors: BATE L. A. , HACKER R. R.
Published: March 2010

To study modifications in adrenal activity, 18 pregnant Yorkshire sows were infused intravenously with either ACTH, metyrapone or saline between days 104 and 114 postbreeding. During this time the sows were bled twice daily. At birth the piglets were force fed pooled bovine colostrum until 6 h of life and bled at birth, 6 h, 1, 2, 4, 8, 12, 16 and 21 days of age. Cortisol, corticosterone, and 11-deoxycortisol were measured in sow serum and the concentrations of bovine and porcine immunoglobulin G (IgG) were measured in piglet serum. ACTH significantly increased the levels of cortisol, corticosterone and 11-deoxycortisol in sows. Metyrapone did not produce a significant reduction in the levels of cortisol or corticosterone but the concentration of 11-deoxycortisol was significantly elevated in comparison to the controls. Piglets from sows treated with ACTH (A pigs) had significantly more bovine IgG than controls (C pigs) at 6 h of life, and maintained higher levels at the other sampling times. Piglets from sows treated with metyrapone (M pigs) had significant increased serum concentrations of bovine IgG from 6 h to 21 days. The concentration of bovine IgG at 6 h was about 71% higher in M pigs than in the C pigs. At birth, M pigs were heavier than A pigs, and C pigs were the lightest of the three groups. Key words: Piglets corticosteroids, IgG, absorption, colostrum
EFFECT OF FORAGE AMOUNT AND PARTICLE SIZE IN DIETS OF LACTATING DAIRY COWS ON SITE OF DIGESTION AND MICROBIAL PROTEIN SYNTHESIS
Authors: RODE L. M. , WEAKLEY D. C. , SATTER L. D.
Published: March 2010

Lactating Holstein cows fitted with ruminal and duodenal T-type cannulae were used in two studies to determine the effect of forage: concentrate ratio and forage particle size on site of nutrient digestion and microbial protein synthesis. In exp. 1, cows were fed alfalfa hay at 24, 38, 58 and 80% of total dry matter intake. Organic matter (OM) digestion in the total tract (OMD) increased with increasing concentrate level but apparent ruminal OM digestion (AROMD) was unaffected by diet. Digestion of acid detergent fiber (ADF) was similar among the higher forage diets, but was depressed at the 24% forage level. Efficiency of microbial protein synthesis (MPS) was depressed by high concentrate diets and was positively correlated (P < 0.05) to turnover rate within the rumen. In exp. 2, cows were fed 20% concentrate and 80% alfalfa hay in long, chopped or ground and pelleted form. AROMD was lower with ground hay but OMD was unaffected by diet. Digestibility of ADF in the rumen was lower with ground hay, but was partially compensated for by increased hindgut digestion of ADF. Flow of feed plus endogenous nitrogen (N) at the duodenum was 37% and 47% on N intake with long and ground hay, respectively. Efficiency of MPS increased 15% and postruminal N digestion increased 36% when ground hay replaced long hay. Efficiency of MPS was directly related to ruminal solids turnover rate and inversely related to liquid dilution rate. These results demonstrate improvements in efficiency of MPS with either increasing amounts of forage in the diet or increased ruminal passage of solids. Key words: Digestion, microbial protein, rate of passage, cattle, rumen forage
EFFECTS OF AGE AT PHOTOPERIOD CHANGE AND DIETARY PROTEIN ON PERFORMANCES OF FOUR DWARF MATERNAL MEAT PARENT GENOTYPES AND THEIR BROILER CHICKEN PROGENY
Authors: PROUDFOOT F. G. , HULAN H. W. , McRAE K. B.
Published: March 2010

A factorial experiment was conducted with 3030 chickens of four maternal dwarf genotypes mated with normal males to estimate the effects of age at a photoperiod change from 8 to 12 h (daily) at 140 or 154 days, and two levels of dietary protein (15 or 17%) on general performance, incidence of Fatty Liver Syndrome and monetary returns. Three of the four maternal genotypes performed similarly for most traits measured but one genotype exhibited better feed efficency of egg production, produced more eggs and, although the eggs were smaller resulted in the highest monetary returns. Delaying the increase in photoperiod change retarded sexual maturity and reduced egg weight at 203 days and egg specific gravity at 406 days. The 17% protein diet improved egg production (including hatching eggs), feed efficiency of egg production, egg weights; and female body weights at 154 and 446 days of age were also heavier. Dietary protein levels had no effect on mortality (P > 0.05). Mean monetary returns from the sale of table eggs, hatching eggs and salvage meat in excess of the costs of day-old breeder stock and feed, averaged $1.07 more per bird fed the 17% diet. The progeny test revealed significant differences among genotypes for male mortality, male and female body weights, and feed conversion; however, monetary returns over feed and chick cost were similar. The time of change in photoperiod and dietary treatments had no significant effect on the overall performance of broiler progeny but there was a genotype × parental diet interaction for 43 day female body weights. Key words: Dwarfs, meat breeders, hens, broilers, photoperiods, diets
RUMINAL DIGESTION OF ALFALFA STRAINS SELECTED FOR SLOW AND FAST INITIAL RATES OF DIGESTION
Authors: KUDO H. , CHENG K.-J. , HANNA M. R. , HOWARTH R. E. , GOPLEN B. P. , COSTERTON J. W.
Published: March 2010

A feeding trial, using six fistulated sheep, was conducted to evaluate two strains of alfalfa that were selected for slow and fast initial rates of digestion (IRD). To determine how these strains affect rumen metabolism, samples of rumen fluid were collected before feeding, as well as 2 h and 4 h after feeding. Concentrations of soluble protein, soluble carbohydrates, chlorophyll, volatile fatty acids and hydrogen ions were significantly lower in rumen fluid from sheep fed slow-IRD alfalfa compared to sheep fed fast-IRD alfalfa. These results show that the bloat-causing potential of alfalfa might be reduced through further breeding for slow-IRD strains. Key words: Bloat, legumes, Medicago sativa L., nylon bag, chlorophyll, pH
EARLY REPRODUCTIVE CHARACTERISTICS OF LEGHORN PULLETS REARED ON LEAST-COST DIETS FORMULATED TO PROTEIN AND/OR AMINO ACID SPECIFICATIONS
Authors: LEESON S. , SUMMERS J. D.
Published: March 2010

Leghorn pullets were reared on one of four dietary programs formulated to (1) conventional least-cost, (2) least-cost to amino acid requirements with no specification for crude protein, (3) as (2) with cost of protein feedstuffs increased 40% and (4) corn-soybean meal. All diets contained 18% and 15% CP, or equivalents, for 0–6 and 6–18 wk, respectively. Diets were offered ad-libitum to 14 replicate groups of 10 caged pullets. Pullets fed the conventional least-cost and corn-soybean diets were heavier (P < 0.05) at 6 wk of age than pullets reared on either of the two diets formulated to amino acid specifications. At 12 and 18 wk of age, conventionally fed birds were heavier than pullets fed amino-acid-based diets, while all groups were heavier than birds fed the corn-soybean diet. To 28 wk of age, pullets reared on amino-acid-based diets under conditions of elevated protein prices, produced more eggs (P < 0.05) relative to pullets reared on treatments 2 and 4. Results confirmed that pullets can be reared on diets formulated without crude protein specifications, and that substantial use of synthetic amino acids is not detrimental to growth or early reproductive performance. Key words: Pullet growth, amino acid formulation
EFFECT OF GESTATION HOUSING ON REPRODUCTIVE PERFORMANCE OF YORKSHIRE AND YORKSHIRE × LACOMBE SOWS
Authors: DYCK G. W. , STRAIN J. H. , SWIERSTRA E. E.
Published: March 2010

Forty-eight Yorkshire (Y) and 48 Yorkshire × Lacombe (YL) primiparous sows were used to evaluate the effect of outside lot and confinement housing from weaning to parturition on reproductive performance over the second to fourth parity. Feed intake of the sows housed in the outside lots was adjusted monthly to provide a similar average gain (54 kg) to that of sows housed in confinement (56 kg). All sows were bred by AI. Sows that did not conceive to mating at the first or second estrus were culled from the experiment. More (P < 0.05) sows housed in the outside lots than in confinement completed the experiment (77.1 vs. 52.1%, respectively). The number of sows that failed to conceive was similar for both treatments but 12 sows housed in confinement and one housed in outside lots were culled due to injury or death. The sows housed in outside lots weaned more (P < 0.01) piglets (8.42 ± 0.23 vs. 7.49 ± 0.25) than those housed in confinement while the number of piglets born (10.20 ± 0.15) and born alive (9.79 ± 0.14) and the weight at birth (1.31 ± 0.02 kg) and weaning (9.45 ± 0.09 kg) were similar. As anticipated, the YL sows farrowed and weaned more and heavier piglets (P < 0.01) than the Y sows. The housing environment did not have a significant effect on the farrowing interval which averaged 159.3 ± 0.6 days. These results indicate that effects of housing conditions from weaning to parturition are limited to the number of sows culled and the number of piglets weaned. Key words: Sows, gestation housing, litter size
COMPARISON OF THE EFFECTS OF DARK AND YELLOW RAPESEED HULLS, SOYBEAN HULLS AND A PURIFIED FIBER SOURCE ON GROWTH, FEED CONSUMPTION AND DIGESTIBILITY OF DIETARY COMPONENTS IN STARTER PIGS
Authors: MITARU B. N. , BLAIR R.
Published: March 2010

A trial involving a total of 56 weanling pigs was conducted to investigate the effects of including dark (Tower) and yellow (R500) rapeseed hulls, soybean hulls and a purified fiber source (Celufil) as 10% of the diets of starter pigs. The animals were offered the experimental diets from 5 to 9 wk of age. The pigs fed on the R500 hull diet had lower (P < 0.05) average weight gain (273 g/day) and feed consumption (481 g/day) values than those fed the other diets, which ranged from 400 to 466 g/day and from 755 to 882 g/day, respectively. The feed efficiency (gain:feed) values were similar for all dietary treatments with values ranging from 0.53 to 0.57. The lower feed consumption observed for the R500 hull diet was suspected to be due to poor palatability of these hulls probably caused by some hydrolytic products of glucosinolates. The dry matter, energy and protein digestibility coefficients for both rapeseed hull diets were similar. The R500 rapeseed hull diet had higher (P < 0.05) digestibility values for dry matter, energy and protein than the soybean hull diet while the Tower rapeseed and soybean hull diets had similar digestibility values for these components. The Celufil diet had similar dry matter and energy digestibility values with the SBH diet but the protein digestibility value for Celufil was higher (P < 0.05) than that of the soybean hull diet and similar to those of the rapeseed hull diets. The crude fiber digestibility values were similar for all diets. Key words: Dark and yellow rapeseed, hulls, fiber, growth performance, digestibility, swine
A COMPARISON OF SPECIFIC GRAVITY AND CARCASS MEASUREMENTS AS PREDICTORS OF BEEF CARCASS COMPOSITION
Authors: JONES S. D. M. , ROMPALA R. E.
Published: March 2010

Carcass specific gravity provided the best prediction of beef carcass fat content, and the best individual prediction of carcass lean content. The prediction of carcass lean content was improved by the addition of simple carcass measurements. However, carcass specific gravity offered only marginal improvements in predicting carcass composition over those provided by simple carcass measurements. Key words: Carcass composition, carcass grading, specific gravity, carcass measurements
LEVELS OF 5α-ANDROST-16-EN-3-ONE (5α-ANDROSTENONE) IN SERUM AND FAT OF INTACT AND CASTRATED MATURE BOARS
Authors: CLIPLEF ROBERT L. , GRINWICH DANIEL L. , McKAY ROBERT M.
Published: March 2010

Castration of mature boars resulted in a progressive decline in serum and loin fat levels of 5α-androstenone. The levels had declined to circa 10% of those of intact boars by 12 wk after castration. Sensory odor scores of loin fat from boars 12 wk after castration were significantly lower than those from intact boars and were consistent with increased acceptability of the product. Key words: Mature boars, castration, 5α-androstenone depletion, sensory odor
CORRELATION COEFFICIENTS BETWEEN NUTRIENTS IN FORAGES
Authors: HINTZ H. F. , SCHRYVER H. F. , WILLIAMS J.
Published: March 2010

Simple correlation coefficients between all possible combinations of Ca, P, crude protein and acid detergent fiber (ADF) were calculated from the analyses of 82 legume, 102 mixed, mostly legume, 143 mixed, mostly grass, and 101 grass hay samples. The correlation coefficients were different from zero (P < 0.01) for all combinations except for Ca and P in legume hay and in mixed, mostly legume hay and for Ca and ADF, and P and ADF in legume hay. However, it was concluded that predictions of the contents of crude protein, Ca, P, or ADF in hay from the contents of any of the other three nutrients could be misleading. Key words: Forage, calcium, grass, legume, phosphorus, protein
EFFECTS OF SALINOMYCIN AND LINCOMYCIN UPON PERFORMANCE, MORTALITY AND INTESTINAL LESION SCORE IN BROILER CHICKENS USING AN IN-FEED COCCIDIA MODEL
Authors: WHEELHOUSE R. K. , GROVES B. I. , HAMMANT C. A.
Published: March 2010

A floor pen trial using an in-feed coccidia model was conducted to determine the efficacy of salinomycin at the rate of 60 mg/kg of feed and to ascertain any interference of lincomycin at 2.2 mg/kg upon salinomycin efficacy in broiler chickens. Inclusion of salinomycin effectively controlled mortality due to coccidiosis (P < 0.05), and improved mean intestinal lesion score and performance (P < 0.05). Addition of lincomycin to the diet did not interfere with the coccidiostatic properties of salinomycin. Key words: Broiler chickens, coccidiosis, salinomycin, lincomycin
COMPOSITION AND STORAGE CHARACTERISTICS OF WET CORN GLUTEN FEED
Authors: DROPPO T. E. , MACLEOD G. K. , GRIEVE D. G.
Published: March 2010

Analysis of fourteen 6-tonne loads of wet corn gluten feed showed variable levels of protein and minerals. The product stored without spoilage at 6 °C, but at 17 or 26.5 °C application of propionic acid, formic acid or a 37% solution of formaldehyde at 0.5% wt/wt/was necessary to prevent spoilage for 2–3 wk. Key words: Wet corn gluten feed, composition, keeping qualities, preservatives
AN AUTOMATED DEVICE FOR CONTROLLED FEEDING OF SHEEP IN CAGES OR PENS
Authors: BUCKLEY D. J. , NICHOLLS C. F. , ST. AMOUR G. , VEIRA D. M. , IVAN M.
Published: March 2010

A machine for feeding sheep at selected frequent intervals is described. The feeder is compact, mobile and can be used to feed one or two sheep in separate pens or metabolism cages under a wide range of time sequences. Key words: Automated feeder, controlled feeding, sheep
FAT GROWTH AND PARTITIONING AMONG THE DEPOTS IN DOUBLE MUSCLED AND NORMAL CATTLE
Authors: SHAHIN KARIMA A. , BERG R. T.
Published: March 2010

Eighteen Double Muscled (DM), 18 Beef Synthetic (SY) and 18 Hereford (HE) bulls were serially slaughtered from approximately 250 to 800 kg liveweight to determine the influence of maturity type and "double muscling" on fat growth, partitioning and distribution. The fatty tissue was dissected into subcutaneous fat (SCF), intermuscular fat (IMF) and carcass cavity fat (CCF); the sum of these depots was used as total side fat (TSF). Relative to TSF, DM did not differ significantly from the other maturity types in growth rates of SCF, IMF and CCF, but relative to fat percent in the side, DM tended to have much lower growth rates for SCF and CCF. The common growth coefficients indicated that as TSF increased the proportion of SCF increased (b > 1; P < 0.05), the proportion of IMF decreased (b < 1; P < 0.05), and the proportion of CCF remained relatively constant (b = 1; P > 0.05). At equal TSF, as expected, HE tended to partition more of their fat to the subcutaneous depot, whereas DM and SY tended to partition more of their fat to the intermuscular and carcass cavity fat depots. Relative to HE, DM followed late-developing fat partitioning patterns. The hypodevelopment of fat depots in the carcasses of the muscular hypertrophied animals followed an inner-outer gradient which was most pronounced in the subcutaneous fat depot. Key words: Cattle, fat growth, double muscling, breed type
GROWTH AND DISTRIBUTION OF MUSCLE IN DOUBLE MUSCLED AND NORMAL CATTLE
Authors: SHAHIN KARIMA A. , BERG R. T.
Published: March 2010

Eighteen Double Muscled (DM), 18 Beef Synthetic (SY) and 18 Hereford (HE) bulls, serially slaughtered from approximately 250 to 800 kg liveweight, were used to determine the influence of maturity type and "double muscling" upon muscle growth patterns and distribution. The left side of each carcass was dissected into major carcass tissues and the weights of individual muscles were obtained and grouped into nine standard anatomical groups. Relative to total side msucle (TSM), breed types tended to have similar growth coefficients for all muscle groups except muscles surrounding the spinal column where HE tended to have a higher growth coefficient than either DM or SY. As TSM increased, the proportion of muscle found in proximal hindlimb, distal hindlimb and distal forelimb decreased (b < 1; P < 0.05), the proportion of muscle in abdominal wall and proximal forelimb remained relatively constant (b = 1; P > 0.05) and the proportion of muscle in thorax to forelimb, neck to forelimb and intrinsic muscles of neck and thorax increased (b > 1; P < 0.05). At the same TSM, compared with the other breed types, DM tended to have more of their muscle in the hip and stifle region but less in the distal parts of both limbs and in neck and thorax. The hyperdevelopment of the large superficial muscles of the proximal part (thigh) and the hypodevelopment of the distal part in the hindlimb give the DM animal the typical 'bottle thigh' appearance. Key words: Bulls (young), muscle growth, muscle distribution, Double Muscled, cattle
COMPARISON OF THREE METHODS OF PREDICTING 305-DAY MILK AND FAT PRODUCTION IN DAIRY COWS
Authors: BATRA T. R. , LEE A. J.
Published: March 2010

The data used in this study consisted of 119 075 complete lactation records accumulated by record of performance (ROP) from 1976 to 1981. Each individual record consisted of 7, 8 or 9 monthly test day milk weights and corresponding fat percentage. The data for each breed (Ayrshire, Guernsey, Holstein, Jersey) were grouped into two ages at freshening — less than 36 mo and greater than or equal to 36 mo. Months of calving were grouped into four seasons: March to May, June to August, September to November, and December to February. For both milk and fat yield, separate sets of extension factors to predict 305-day yield were estimated for each breed, group, and season of calving, using three methods (multiplicative, regression, nonlinear model). A new set of data collected by ROP during 1982 was used to compare three sets of extension factors. The nonlinear model method was better than either the multiplicative or regression methods because of smaller bias and better precision, and because it can be easily implemented in Canadian milk recording programs. Separate extension factors are not required for different geographic zones allocated by ROP. Key words: Extension factors, cattle (dairy)
PATTERNS OF MUSCLE, BONE, AND FAT ACCRETION IN THREE BIOLOGICAL TYPES OF FEEDLOT BULLS FED THREE DIETARY ENERGY LEVELS
Authors: PATTERSON D. L. , PRICE M. A. , BERG R. T.
Published: March 2010

The effect of three types of diet on the carcass composition of 71 feedlot bulls of three biological types (Dairy Cross (DX), Hereford Cross (HX), and Beef Cross (BX)) was studied over a 2-yr period. Diets consisted of pelleted alfalfa with 0, 35 or 85% grain. Serial slaughter and carcass dissection into eight wholesale cuts and component tissues were carried out over an age range of 392–636 days. Interactions of biological type with diet-year were generally not significant for actual weight of muscle, bone and fat, or for weight of these tissues at a constant side subcutaneous fat weight of 16 kg. There were few significant effects of biological type or diet-year on the ratio of actual weight of subcutaneous to intermusclar plus body cavity fat. HX bulls had significantly less muscle and less bone than BX or DX, based on actual weights, but the rate of tissue accretion relative to side subcutaneous fat was the same for the three biological types. Animals on the lowest level of dietary energy had less weight of fat than did those on an 85% grain diet, but diet-year growth coefficients of tissue weights relative to side subcutaneous fat weight were generally homogeneous. It was concluded that effects of dietary energy were consistent over the biological types studied and for most of the wholesale cuts. Key words: Feedlot bulls, diet, biological types, tissue growth
METABOLIC RATE AND PLASMA THYROID HORMONE CONCENTRATIONS OF MATURE HORSES IN RESPONSE TO CHANGES IN AMBIENT TEMPERATURE
Authors: McBRIDE G. E. , CHRISTOPHERSON R. J. , SAUER W.
Published: March 2010

Metabolic rate was assessed at controlled environmental temperatures in six winter-acclimatized mature Quarter Horse geldings. Within an environmental chamber maintained at 18 °C, metabolic rate was similar (P > 0.05) at the beginning (November) and end (mid-January) of the trial. During periods of acute cold exposure (6 h), metabolic rate was found to be elevated (P < 0.05) at temperatures below −10 °C, increasing to 142% of basal metabolic rate values at −40 °C. At temperatures above 10 °C, metabolic rate tended to be elevated (P < 0.07) over basal levels recorded at 0 °C. Thyroid hormone responses to temperature were monitored by evaluating total plasma T3 and T4 in blood samples collected from the jugular vein. Basal plasma T3 and T4 concentrations were both observed to rise (P < 0.05) during the experiment while the horses were exposed to outdoor ambient temperature. Short-term cold exposure within the environmental chamber had no effect on either plasma T3 or T4 concentration (P > 0.05). These results indicate that the thermoneutral zone of the mature horse housed outdoors during winter ranges from approximately −15 °C to 10 °C. During this experiment, outdoor housing did not result in winter acclimatization, as reflected by the constancy of metabolic rate estimates, although changes in basal concentrations of T3 and T4 were observed. Key words: Horses, metabolic rate, thyroid hormones, temperature
RESUMPTION OF OVARIAN ACTIVITY AND ESTRUS POSTPARTUM IN DAIRY COWS MAINTAINED INDOORS YEAR-ROUND
Authors: HACKETT A. J. , LIN C. Y. , McALLISTER A. J.
Published: March 2010

Sequential milk progesterone concentrations from semi-weekly samples were plotted for 310 calvings by cows housed indoors year-round. Resumption of ovarian activity (first estrus), number of complete estrous cycles within 91 days postpartum, lengths of estrous cycles and peak progesterone levels were assessed considering diet, parity, genetic line of cow and season of calving. Patterns of ovarian activity in postpartum cows maintained indoors year-round were similar to those previously reported for cows housed in less intensive systems. On the average, the first estrus occurred 24 days postpartum. The mean number of estrous cycles was 2.6. Estrous cycle lengths averaged 20 ± 6, 22 ± 5 and 22 ± 5 days (mean ± SD) in the first three estrous cycles. Peak progesterone levels were 19 ± 10, 20 ± 10 and 22 ± 12 ng/mL (mean ± SD). Most of the dairy cows housed in the intensive system had normal estrous cycles, had ovulated within 55 days postpartum and had two periods of estrus within 91 days postpartum and should have been capable of conception at such a time to have a calving interval of 1 yr. Seasonal influences on ovarian activity were more important than diet, genetic line or parity. Of 48 interaction effects studied, only interactions of season with genetic group, parity or diet were significant, as was genetic group with parity. Key words: Ovarian activity, estrous cycle, peak progesterone
GROWTH AND MODIFICATION OF DIGESTION IN LAMBS FED DIETS CONTAINING CEMENT KILN DUST
Authors: BUSH R. S. , NICHOLSON J. W. G. , CALDER F. W.
Published: March 2010

Three experiments were conducted to determine (1) the effect of cement kiln dust (CKD) on the growth of lambs fed high- or low-roughage diets, (2) the effect of pelleting on lamb diets which contain CKD, and (3) the effect of different levels of dietary CKD on lamb performance. In exp. 1, lambs were fed complete pelleted diets containing 15 or 45% ground timothy hay with either 0 or 3% CKD. There were no differences in weight gain due to CKD addition. The feed consumed was greater for the high roughage-CKD group (P < 0.05). Feed:gain ratios were greater for the high-roughage groups (P < 0.01). The pH of gastrointestinal tract contents showed an increase due to CKD only in the cecum and colon. The carbohydrate level in the colon of lambs fed the low-roughage rations was lower (P < 0.05) with added CKD. In exp. 2, lambs were fed CKD diets in mash and pelleted form, a complete pelleted CKD diet (including hay) or a mash CKD-free control. All diets except the complete pelleted-CKD diet were fed with hay, ad libitum. Lambs fed the pelleted CKD diet plus hay grew faster than the control group (P < 0.05) with growth in the other groups not different from either extreme. In exp. 3, lambs were fed similar diets containing 0, 1, 2 or 3% CKD. Growth was not different for any of the groups. Fecal pH was elevated in two of the CKD groups. Analysis of feces showed no difference in nitrogen, soluble carbohydrate, ADF or NDF as a percent of organic matter. Fecal ash increased with increasing level of CKD (P < 0.01). Key words: Lamb, cement kiln dust, growth rate, digesta pH
INFLUENCE OF LEVEL OF FEED INTAKE ON DIGESTION AND BACTERIAL YIELD IN THE FORESTOMACHS OF DAIRY CATTLE
Authors: ROBINSON P. H. , SNIFFEN C. J. , SOEST P. J. VAN
Published: March 2010

Four dairy cows fitted with duodenal T-type cannulae were fed a diet containing 65% forage to determine effects of diet intake level on digestion and bacterial yield in the forestomachs. Intake ranged from 5.99 to 17.40 kg organic matter (OM) per day. Apparent digestion of OM and neutral and acid detergent fiber was depressed disproportionally more than the increase in intake (60.2–41.8%, 63.1–49.8%, and 59.0–46.2%, respectively), and that observed for OM was most pronounced. However, if OM digestion was expressed as feed OM truly digested in the rumen, then the depression in OM digestion was less pronounced (71–57%) than for fiber, suggesting that non-fiber dietary components may be less susceptible than fiber to depressions in digestibility at higher intake levels. Non-ammonia and bacterial nitrogen (N) flow at the duodenum increased proportionally more than intake (97.4–402.8 g/day and 64.0–271.0 g/day, respectively). Bacterial N yield increased at an increasing rate as intake level increased (17.4–38.2 g bacterial N/kg OM apparently digested) suggesting that a constant value for bacterial yield may be inappropriate for all levels of intake. Key words: Rumen digestion, bacterial yield, dairy cattle, feed intake, forestomach
PERMANENT RE-ENTRANT DIVERSION OF PORCINE PANCREATIC SECRETIONS
Authors: HEE J. H. , SAUER W. C. , BERZINS R. , OZIMEK L.
Published: March 2010

A surgical procedure was developed to permit improved long-term collection of exocrine pancreatic secretions. A cannula was used to conduct pancreatic juice from a small isolated segment of duodenum which received the pancreatic duct, through permanent intercostal fistulas, and back into the duodenum within 3 cm of the normal entry point for pancreatic juice. Success with this procedure is attributed to fistula location, one-way valve design of the re-entrant arm of the cannula and precautions taken to minimize the formation of intra-abdominal adhesions. Pancreatic juice was collected from three barrows (35 kg initial weight) which were fed three cornstarch-based diets (high fat — 14% crude protein, 10% tallow; control — 14% crude protein, 2% tallow; protein-free — 0% crude protein, 2% tallow), twice daily, 0.9 kg each meal, 12 h apart for a 2-wk period. The daily volume of pancreatic juice secreted was 3.9, 4.0 and 3.5 L (n = 6) for the high fat, control and protein-free diets, respectively. In the same order for the diets, the daily protein secretion was 15.3, 15.0 and 12.2 g respectively. A 12-h secretion profile related to meal time showed a similar response pattern to feeding for all diets, i. e., secretion rates increased within the first 3 h, peaked during 3–7 h and decreased to basal rates during the last 5 h. Secretion rates obtained from blind 5-cm duodenal pouches did not exceed 20 mL per 24 h. During the 4-mo study, pancreatic secretions were persistent and meal induced secretion patterns were sustained. Cannulas were still functional when pigs achieved liveweights greater than 100 kg. Key words: Cannulation, pancreas, swine
METACARPAL AND METATARSAL DIMENSIONAL, MECHANICAL AND MINERAL CHARACTERISTICS OF CROSSBRED BOARS AS INFLUENCED BY NUTRITION AND AGE
Authors: LEPINE A. J. , KORNEGAY E. T. , KNIGHT J. W. , NOTTER D. R. , BARTLETT H. S. , VEIT H. P. , BAKER J. L.
Published: March 2010

Crossbred boars (35 days of age) were assigned in a 2 × 2 factorial arrangement to dietary energy (ad libitum and 75% of ad libitum) and mineral-vitamin (100 and 150% of National Academy of Sciences-National Research Council (NAS-NRC 1979) recommendation) intakes to determine the effects on metacarpal and metatarsal dimensional and mechanical characteristics and chemical composition. The third and fourth metacarpal and metatarsal were removed from boars necropsied at 15-day intervals from 85 to 295 days on test. Bone weight, length, shaft diameter and wall thickness increased with age, while bone ether extract decreased and ash content increased. As age increased, percentage Ca content of bone ash increased, P content remained unchanged and Mg, Cu, Zn, Fe and Mn content decreased. At an equal age, bone weight, length, shaft diameters and mechanical characteristics were greater for ad libitum-fed boars; however, weight-correction produced trends in favor of the limit-fed boars. Although mineral-vitamin level had no effect on the weight, length or diameter of bones, the 150% NAS-NRC mineral-vitamin level increased bone wall thickness and bone mechanical properties, with these effects more prominent in the metatarsals than the metacarpals. Metatarsals were heavier and longer than metacarpals. Percentage of ether extract was higher for ad libitum-fed boars. The 150% NAS-NRC mineral-vitamin level increased percentage bone ash and bone ash Ca level, while dietary energy or mineral-vitamin levels failed to affect content of any of the other bone ash minerals examined. The results of this study indicate that changes in bone characteristics resulting from ad libitum feeding are due to a larger body size at a given age, while higher values for mechanical characteristics can be obtained by elevation of dietary mineral-vitamin levels. Key words: Boars, energy intake, minerals, vitamins, bone characteristics, bone mineral composition
NUTRITIONAL SIGNIFICANCE OF SELENIUM SUPPLEMENTATION IN A SEMI-PURIFIED DIET FED DURING GESTATION AND LACTATION TO FIRST-LITTER GILTS AND THEIR PIGLETS
Authors: CHAVEZ E. R.
Published: March 2010

Twelve purebred Landrace pregnant gilts were introduced to the experimental diets in pairs (littermates) in order to study the nutritional significance of 0.1 ppm Se supplementation (+Se) during gestation and lactation in a semi-purified diet containing adequate amounts of vitamin E but low in Se (0.018 ppm; −Se). Gilts were fed 2 kg/day during gestation and ad libitum during a 3-wk lactation. Animal response was evaluated in terms of reproductive performance, blood, colostrum and milk parameters. Litter size and total litter weight at birth and at weaning were not affected by the Se levels fed to the dams. Mortality rates at birth were 1.61 and 13.64% and from birth to weaning were 18.09 and 5.26% for +Se and −Se litters, respectively. A continuous decrease of blood Se content was observed in gilts throughout gestation, being significantly lower for the −Se group compared to the +Se group. Plasma glutathione peroxidase (GSH-Px) activity followed the same pattern observed in blood Se content. Content of Se in colostrum, although always higher than in milk, was significantly lower in the −Se gilts than the +Se group. Blood Se from piglets of the +Se gilts was significantly higher than the blood of piglets from litters of the −Se gilts at birth, and during the 3-wk lactation. Levels of GSH-Px activity in the plasma of piglets from litters of the two experimental groups of gilts were similar at birth, but by 3 wk lactation piglets from +Se gilts showed significantly greater GSH-Px activity than piglets from −Se gilts. Growth rate of the piglets at 4 wk postweaning was significantly affected by the dietary Se intake of their mothers during gestation and lactation. However, no differences in growth rate were observed among littermates that received a starter diet with or without Se supplementation. Key words: Selenium, gilts, pregnancy, lactation, piglets, postweaning