bluuebunny/crossref_metadata_2025 huggingface dataset:
INFLUENCE OF PARTICLE SIZE OF CONCENTRATE ON RUMEN CONDITIONS ASSOCIATED WITH FEEDLOT BLOAT
Authors: HIRONAKA R. , MILTIMORE J. E. , MCARTHUR J. M. , MCGREGOR D. R. , SMITH E. S.
Published: March 2010

Some rumen characteristics associated with bloat were measured in identical twin cows fed diets of coarse and fine particle size (geometric mean particle size of 715 and 388 μ). A foamy condition developed in the rumen of all cows fed the fine diet and in one of those fed the coarse diet on the 2nd day of the experiment. In vitro gas production 1 h after feeding was 3.46 ml/h per g dry matter (DM) on fine feed and 2.35 ml/h per g DM on the coarse (P < 0.05). During the 1st week of feeding the pH value of rumen of cows fed the coarse diet was 4.86 and that of cows fed the fine diet was 4.75. During the 2nd week the pH of both were lower at 4.53 and 4.12 (P > 0.05). There was no difference in the numbers of Streptococcus bovis present in the rumen attributable to the particle size of the diet. The number of S. bovis increased with an increasing proportion of concentrate fed until the cows were changed to the all-concentrate diet, when numbers declined sharply to a low level. S. bovis does not appear to be a primary cause of feedlot bloat.
EFFECTS OF ENVIRONMENTAL TEMPERATURE AND DIETARY COPPER ON GROWTH AND LIPID METABOLISM IN PIGS. I. GROWTH, CARCASS QUALITY, AND TISSUE COPPER LEVELS
Authors: MYRES A. W. , BOWLAND J. P.
Published: March 2010

An experiment was conducted to compare the effects of 0 or 250 ppm supplemental dietary copper added to a barley–herring meal diet on growth, carcass quality, and tissue copper levels in pigs kept under different environmental conditions. The pigs were kept during winter either outside (−14.5 C), with unheated colony houses for shelter (−0.4 C), or in a heated barn (15 C). Growth data indicated that the performance of pigs kept in the heated barn was superior (P < 0.01) to that of pigs kept outside. Dietary copper appeared to have some growth-promoting effect under both types of environment, but the overall effect was not significant (P < 0.05). There were significant (P < 0.001) increases in the copper content of the liver and kidney due to dietary copper with a trend toward lower liver copper levels in these organs in pigs kept under outside conditions. There was an improvement in carcass quality associated with copper supplementation with no interaction between diet and environment.
EFFECTS OF ENVIRONMENTAL TEMPERATURE AND DIETARY COPPER ON GROWTH AND LIPID METABOLISM IN PIGS. II. FATTY ACID COMPOSITION OF ADIPOSE TISSUE LIPIDS
Authors: MYRES A. W. , BOWLAND J. P.
Published: March 2010

Pigs were fed diets with and without 250 ppm supplemental copper and kept outside during winter with unheated colony houses for shelter, or in a heated barn. Lipids were extracted from the outer backfat and pure triglycerides were prepared by thin-layer chromatography. Fatty acid analysis indicated only minor changes in fatty acid composition of the triglycerides due to either dietary copper or environmental temperature. Fatty acid analysis of the total lipid extract, however, indicated that there were differences between the two methods of evaluation. The lipid extract analysis gave a more unsaturated fatty acid pattern than that of the pure triglycerides. Although the fatty acid composition was not altered significantly by type of rearing (outside vs. inside), there was an increased proportion (P < 0.05) of unsaturated fatty acids (UFA) due to dietary copper when the fatty acid composition was determined on the lipid extract. This suggests that lipid fractions other than triglycerides were enriched in UFA and that the effect of dietary copper on the fatty acid composition of adipose tissue lipid is due to changes in the composition of other lipid fractions, possibly free fatty acids. This may be related to a disturbance in the balance between lipolysis and reesterification of fatty acids.
EFFECTS OF SUPPLEMENTAL DIETARY COPPER ON GLYCERIDE DISTRIBUTION IN THE BACKFAT OF PIGS
Authors: AMER M. A. , ELLIOT J. I.
Published: March 2010

The depot fat triglyceride composition of pigs fed 250 ppm supplemental dietary copper from 18 to 23, 46, 69, or 92 kg was determined to further elucidate the effects of supplemental copper on triglyceride composition in the pig. The presence of supplemental copper in the diet significantly (P < 0.01) decreased the amount of 16:0 and increased the amounts of 16:1, 18:1, and 18:2 esterified at the 2 position of porcine backfat triglycerides. Removal of copper from the diet at 23, 46, or 69 kg eliminated these effects in samples taken from such pigs at slaughter (92 kg). The observed alterations in the positional distribution of fatty acids in porcine triglycerides was related to changes in the fatty acid composition of porcine depot fat associated with copper supplementation of the diet. Alterations in the concentration of isomeric triglycerides was also noted and is discussed.
NUTRITIVE VALUE OF AIR-CLASSIFIED RAPESEED FRACTIONS
Authors: LESLIE A. J. , SUMMERS J. D. , JONES J. D.
Published: March 2010

Three samples of rapeseed, composed of high, medium, and low glucosinolate cultivars, were air-classified into various fractions and these fractions were subjected to chemical and biological evaluation. The dehulled fraction of the seed had higher protein and fat content and lower fiber content than the original seed. Digestible nitrogen (DN) and digestible energy (DE) content increased when the hull was removed. Net protein utilization was also higher in the dehulled seed than in the intact seed. No effects of glucosinolate level in the seed were noted with respect to DN or DE but feed consumption of chicks was increased on all tests when the low glucosinolate meal was fed.
EFFECTS OF FREQUENCY OF FEEDING ON ENERGY METABOLISM AND BODY COMPOSITION OF YOUNG PIGS
Authors: SHARMA V. D. , YOUNG L. G. , BROWN R. G. , BUCHANAN-SMITH J. , SMITH G. C.
Published: March 2010

The influence of frequency of feeding on the coefficient of digestibility and metabolizability of dietary energy, fasting heat production, maintenance energy requirements, efficiency of utilization of metabolizable energy (ME) for maintenance and growth, net energy value of diet, rate of lipogenesis in adipose tissue, and the body composition of young pigs was investigated. A total of 40 pigs was used in this study, of which four constituted the initial slaughter group. The remaining 36 pigs were allotted to a feeding experiment of a randomized complete-block design involving a 3 × 2 factorial arrangement (level of dietary energy inputs: 140, 240, and 340 kcal ME/W0.75kg daily; and feeding frequency: two and five times daily). One metabolism experiment was conducted during the 3rd wk of the 37-day feeding experiment. Subcutaneous adipose tissue slices taken immediately after electrocution of 24 pigs were used to determine the rate of lipogenesis as indicated by the metabolism of glucose-U-14C. Frequency of feeding had no effect on the digestible energy, ME, and NEm value of the diet or the efficiency of utilization of ME for maintenance. However, frequent feeding increased the fasting heat production, metabolizable energy requirement for maintenance, net efficiency of utilization of metabolizable energy for production and the NEg value of the diet. Frequency of feeding did not produce any change in the weights of empty stomach or small intestine. Although the rate of lipogenesis in the adipose tissue was not affected by feeding frequency, lipogenesis was increased by an increase in the level of dietary energy inputs. Feeding frequency did not influence the body composition and energy concentration in the empty body of pigs fed 240 and 340 kcal ME/W0.75kg but frequent feeding increased percent water and reduced percent fat in pigs fed 140 kcal ME/W0.75kg daily. Several of the latter pigs were in negative energy balance.
EFFECTS OF SHORT PERIODS OF LOW TEMPERATURE STRESS AT 17 DAYS INCUBATION ON HATCHABILITY AND EMBRYONIC DEVELOPMENT
Authors: LEVENICK C. K. , KONDRA P. A.
Published: March 2010

Four groups of 80 eggs each were subjected to a low temperature stress of 3.8 C for 0, 4, 5, or 8 h, respectively, commencing after 17 days (408 h) incubation. Samples of these eggs were examined at 18.0, 19.5, 20.5, and 21.5 days incubation to study the treatment effect on embryonic development, and the remainder of the eggs were incubated for 22 days to determine the effect on hatchability. Hatchability was significantly reduced by 5 and 8 h of exposure to 3.8 C whereas 4 h of exposure caused a nonsignificant reduction in hatchability. Examination of embryos that failed to hatch revealed a high incidence of malpositions and abnormal hatching muscles. Malpositions occurred as early as 18 days incubation whereas edema, or hemorrhage, or both, of the hatching muscle did not begin to develop until 19.5 days. By 20.5 days of age the hatching muscles of the 8-h stressed group were significantly heavier than all other groups. The weight of the hatching muscle from the 5- and 8-h exposure groups increased continually during incubation whereas those of the controls and 4-h stress group had begun to decrease by 20.5 days and 21.5 days, respectively.
PROPYLENE GLYCOL AND GLYCEROL AS A FEED ADDITIVE FOR LACTATING DAIRY COWS: AN EVALUATION OF BLOOD METABOLITE PARAMETERS
Authors: SAUER F. D. , ERFLE J. D. , FISHER L. J.
Published: March 2010

An extensive trial for testing the antiketogenic potency of glycerol and propylene glycol (DL-1,2 propanediol) was conducted with milking Holsteins and Ayrshires over a 2-yr period. Through weekly blood analyses of free fatty acids, glucose, β-hydroxybutyrate, and acetoacetate for an 8-wk period post-partum, it was possible to classify these cows as normal, clinically ketotic, and subclinically ketotic. The results showed that in cows that were not stressed by either high lactation yield or low concentrate intake these chemical additives only slightly depressed blood ketones and free fatty acids below control values. The beneficial properties of these additives became obvious in cows stressed by adverse environmental factors and slightly reduced levels of concentrate intake. In these cows, the addition of propylene glycol to the concentrate ration significantly reduced blood ketones and plasma free fatty acids and increased the concentration of blood glucose. It was concluded that the use of propylene glycol as a feed additive (3 and 6% of the concentrate) should be economically attractive in high-producing dairy herds because it will significantly decrease the incidence of clinical and subclinical ketosis in cows during the immediate postpartum period (4–8 wk) when they are most susceptible to the metabolic disorder.
COMPARATIVE VALUE OF SOYBEAN, RAPESEED, AND FORMALDEHYDE-TREATED RAPESEED MEALS IN UREA-CONTAINING CALF RATIONS
Authors: SHARMA H. R. , INGALLS J. R.
Published: March 2010

Twenty-four Holstein calves were fed three experimental rations containing either 14% soybean meal, 20% rapeseed meal, or 20% formaldehyde-treated (0.7 g formaldehyde/100 g protein) rapeseed meal from 8 to 22 wk of age. No significant differences (P > 0.05) were observed in feed consumption, dry matter intake, liveweight gain, and feed conversion among the three groups. There was a significant (P < 0.05) reduction in rumen ammonia levels in calves receiving the treated rapeseed meal compared with the untreated rapeseed meal rations. Plasma urea levels and rumen fluid volatile fatty acids (mmol/100 ml and molar percent) did not differ significantly (P > 0.05) among treatments. There were no significant differences in the digestibilities of dry matter, nitrogen, acid detergent fiber, and gross energy among treatments, although treating the rapeseed meal with formaldehyde tended to reduce dry matter, nitrogen, fiber, and energy digestibility.
ABSORPTION OF STEAM-VOLATILE FATTY ACIDS FROM THE RUMEN OF THE COW AS INFLUENCED BY DIET, BUFFERS, AND pH
Authors: THORLACIUS S. O. , LODGE G. A.
Published: March 2010

Observations were made on the absorption of steam-volatile fatty acids from the temporarily isolated, washed ventral sac of the rumen of the conscious cow. At pH 7.0, absorption of fatty acids from a 50-mM bicarbonate buffer was similar to that obtained with a 40-mM phosphate buffer. With higher levels of phosphate (75 mM) and bicarbonate (90 mM) at pH 7.0, fatty acid absorption appeared to be lower from the bicarbonate buffer. When cows were fed a high concentrate diet, absorption of fatty acids was more rapid than when the diet had been all hay. Lowering the pH of experimental solutions increased fatty acid absorption. Clearance (amount absorbed divided by the fatty acid concentration) of fatty acids increased progressively with increasing chain length of the acids as the pH dropped below 7. Taking acetate clearance as 1.0, the clearance of propionate and butyrate, respectively, were 1.1 and 1.0 at pH 7.0; 1.2 and 1.4 at pH 6.5; and 1.6 and 2.4 at pH 5.5. Varying acetate and propionate concentrations did not influence the clearance of the fatty acids.
EFFECTS OF INCREASING THE ENERGY VALUE OF A WHOLE MILK DIET FOR CALVES. II. GROWTH, FEED UTILIZATION, AND HEALTH
Authors: LISTER E. E. , LODGE G. A.
Published: March 2010

In each of three growth trials, Holstein male calves grew significantly faster (P < 0.05) when whole milk was supplemented with the energy sources glucose (cerelose) or butterfat. In two trials, growth rates of 819 and 829 g/day were obtained on whole milk with energy values of 21.7 and 23.8 kcal digestible energy (DE)/g digestible crude protein (DCP), respectively, compared with gains of 1,023 and 986 g/day obtained by increasing the dietary energy value to 28 kcal DE/g DCP by glucose supplementation. Further increases in energy:protein ratio tended to reduce liquid intakes and growth rates, but adjustment by covariance to equal protein intakes showed significantly higher growth rates (P < 0.05) on supplemented milk with 31–32 kcal DE/g DCP than on normal whole milk. Protein consumed per unit weight gain was decreased significantly (P < 0.05) by increasing the energy of a whole milk diet, but very high levels of added cerelose (> 13% of the liquid diet) caused severe diarrhea and reduced intakes and growth. The addition of 6% cerelose was well tolerated by calves and this level of supplementation produced more efficient growth per unit of protein consumed than lower levels. It was concluded that more suitable energy: protein ratios than commonly used in liquid diets for calves may result in improved protein utilization and thus have economic value.
NITROGEN UTILIZATION BY LACTATING COWS FED UREA-TREATED CORN SILAGE OR GRASS SILAGE
Authors: WALDERN D. E.
Published: March 2010

Nitrogen utilization was studied when eight lactating cows were offered ad libitum urea-treated corn silage (15.3% crude protein) or grass silage (14.5% crude protein), plus a grain ration at 1 kg grain to 3.5 kg of 4% fat-corrected milk, in a digestion and nitrogen (N) balance trial. Analyses of the forages indicated greater acid detergent fiber content for the grass than for the corn silage: 46.8 and 35.1% on a dry matter basis, respectively. Digestibility of dry matter, energy, crude protein, true protein, acid detergent fiber, neutral detergent fiber, and N balance were significantly greater (P < 0.05) for cows fed urea–corn silage than for those fed grass silage. The nitrogen of urea–corn silage was used more efficiently for milk and tissue protein synthesis. Decreased nitrogen utilization for cows fed grass silage was associated with lower energy and higher acid detergent fiber content for grass silage than for urea–corn silage.
RAPESEED MEAL AS A PARTIAL REPLACEMENT FOR SOYBEAN MEAL IN THE DIETS OF GROWING GILTS AND OF SOWS FOR UP TO THREE REPRODUCTIVE CYCLES
Authors: BOWLAND J. P. , HARDIN R. T.
Published: March 2010

An experiment with 32 crossbred gilts averaging 10 kg at allotment was designed to evaluate prepress-solvent extracted rapeseed meal (RSM) of Brassica campestris origin as a partial replacement for soybean meal (SBM) in diets of sows during growth or growth and reproduction when the sows were retained for three reproductive cycles. Four treatments were involved: (1) sows fed SBM throughout; (2) gilts fed 6% RSM to 90 kg and SBM for the remainder of the experiment; (3) gilts fed 6% RSM to immediately prior to first mating and SBM for the remainder of the experiment; (4) sows fed 6% RSM throughout. A second experiment with 16 mature Yorkshire sows evaluated the same RSM for one reproductive cycle only as a partial replacement for SBM when introduced into the diet immediately prior to breeding. During the growing period to 90 kg, daily feed intake, gain, and feed conversion did not differ significantly for gilts fed 0 or 6% dietary rapeseed meal, daily gain averaging 0.68 kg. Digestible energy, metabolizable energy, digestible nitrogen, and nitrogen retention coefficients were not influenced by level of dietary RSM or by period (15 or 45 kg) at which digestibility studies were conducted. Gestation length, litter size, and weight at birth and weaning were not influenced by dietary treatment in either experiment. Thyroid weights and ratio of thyroid weight to body weight of representative 2-wk-old female pigs did not differ significantly between treatments. In the first experiment, there was an average disposal of 23% of the sows per reproductive cycle because of failure to breed, failure to conceive, and other causes but these removals did not appear to be associated with treatment. The overall results suggest that up to 6% RSM of the type fed is not detrimental to sow performance when the RSM is fed during growth, throughout growth and reproduction, or when introduced suddenly at the time of breeding.
EFFECTS ON BROILER PERFORMANCE OF A SINGLE GENERATION OF SIRE SELECTION FOR BODY WEIGHT AT EIGHT WEEKS OF AGE FROM TWO COMMERCIAL PARENTAL GENOTYPES REARED ON SIX DIETARY TREATMENTS
Authors: PROUDFOOT F. G.
Published: March 2010

Two tests were conducted to evaluate parental effects on broiler performance involving two genotypes. The effects of a single generation of divergent sire selection for 8-wk body weight and the effects of different rearing period dietary treatments were investigated. Data from these tests support the contention that a practical gain in broiler performance may be expected from a single generation of divergent selection of parental sires for 8-wk body weight. The results also provide evidence that despite a wide variation in the methods of feeding parental stocks during the rearing period there was no significant effect on broiler performance.
INFLUENCE OF RESHEARING JUST PRIOR TO BREEDING ON REPRODUCTIVE PERFORMANCE OF A SOUTHDOWN FLOCK SELECTED FOR DATE OF BIRTH
Authors: THRIFT F. A. , DUTT R. H.
Published: March 2010

Data involving 130 ewe-yr observations were collected over a 2-yr period from a flock of purebred Southdown sheep that had closed to outside breeding since 1957 and selected for date of birth. Three treatments were imposed on the flock just prior to the breeding season: (1) rams unsheared, ewes unsheared; (2) rams sheared, ewes unsheared; and (3) rams sheared, ewes sheared. All ewes and rams were shorn each year during the 2nd wk of May. The ewes and rams were reshorn according to treatment each year on 28 July and a 120-day breeding period began immediately thereafter. The ewe traits studied were date of first estrus, date of conception, lambing date, lambs born per ewe lambing, and lambs reared per ewe lambing. The data were analyzed using a statistical model that included year, treatment, year by treatment interaction, and sire within year and treatment. Year, treatment, and the year by treatment interaction were all nonsignificant sources of variation influencing the various traits. However, sire to which the ewes were bred was a significant source of variation for date of first estrus, date of conception, lambing date, and lambs born per ewe lambing, but was nonsignificant for lambs reared per ewe lambing.
RELATIONSHIP OF WEIGHTS OF CHEMICAL COMPONENTS AND EMPTY BODY WEIGHT IN YOUNG PIGS
Authors: SHARMA V. D. , YOUNG L. G. , SMITH G. C.
Published: March 2010

The influence of genotype, sex, frequency of feeding, and plane of nutrition on the relationship between weights of chemically determined components in the empty bodies and the empty body weight was estimated by the use of simple linear regression analyses. The data used were body composition from three experiments involving 107 pigs belonging to Lacombe, Yorkshire, Lacombe × Yorkshire, and Hampshire × Yorkshire breeds representing both sexes and fed at levels of dietary energy inputs varying from 120 to 340 kcal ME/W0.75kg daily. All experiments consisted of a feeding trial and a comparative slaughter analysis. Within a range of 5-35 kg of empty body weight (EBW) the rate of increase in the water, protein, fat, and ash components in the empty body was a linear function of the increase in EBW. The rate of increase in weights of chemical components as a percentage of increase in EBW was: water 60.9; protein 16.3; fat 20.2; and ash 2.7. These estimates were similar for pigs of different breeds and whether fed two or five times daily. The rate of accretion of water per unit increase in EBW was greater in male than in female pigs. Plane of nutrition ranging from 220 to 340 kcal ME/W0.75kg daily did not affect the rate of deposition of water, protein, fat, or ash components per unit increase in EBW. Pigs fed at the maintenance level of feeding (120–140 kcal ME/W0.75kg daily) had a greater rate (P < 0.05) of accretion of water per unit increase in EBW as compared with pigs fed 320–340 kcal ME/W0.75kg per day. The rate of accretion of ash per unit increase in EBW in pigs fed 120–140 kcal ME/W0.75kg per day was greater (P < 0.05) than for pigs fed 220–240 kcal ME/W0.75kg per day. The rate of change in the protein and fat components remained constant. The results are discussed in relation to the concept of mass-related homeostasis.
COMPARISON OF CONTINUOUSLY GRAZED BROMEGRASS–ALFALFA WITH ROTATIONALLY GRAZED CRESTED WHEATGRASS–ALFALFA, BROMEGRASS–ALFALFA, AND RUSSIAN WILD RYEGRASS
Authors: COOKE D. A. , BEACOM S. E. , ROBERTSON J. A.
Published: March 2010

A continuously grazed mixed sward of bromegrass (Bromus inermis Leyss.) and alfalfa (Medicago media Pers.) was compared with two pasture treatments in which separate paddocks of crested wheatgrass (Agropyron cistatum Gaertn.) and alfalfa, bromegrass and alfalfa, and Russian wild ryegrass (Elymus junceus Fish.) alone were grazed in rotation by yearling Hereford steers. In one of the rotationally grazed treatments, Russian wild ryegrass was harvested for seed prior to grazing whereas in the other it was utilized as pasture only. Seventy-five kg N/ha were applied annually (1960–66) to the Russian wild ryegrass. The same amount of N was applied to the bromegrass–alfalfa and crested wheatgrass–alfalfa for only the last 4 yr of the experiment (1963–66). The 7-yr average dry matter yields and steer gains (kg/ha) were 4,794 and 326 for the continuously grazed bromegrass–alfalfa; 3,949 and 343 for the treatment in which Russian wild ryegrass was used exclusively for pasture, and 3,325 and 277, respectively, for the treatment in which Russian wild ryegrass was used for seed and pasture. Harvesting seed from Russian wild ryegrass reduced the dry matter available for grazing from 3,603 to 2,183 kg/ha and liveweight gain from 295 to 168 kg/ha. Seed yield averaged 410 kg/ha.
EFFECTS OF THE DEGREE OF SELECTIVE FEEDING ALLOWED ON FORAGE VOLUNTARY INTAKE AND DIGESTIBILITY ASSAY RESULTS USING SHEEP
Authors: HEANEY D. P.
Published: March 2010

Red clover (Trifolium pratense L.), first- and second-cut alfalfa (Medicago sativa L.), timothy (Phleum pratense L.) hays, and oat (Avena sativa L.) straw were assayed for digestible dry matter (DDM) and dry matter intake (DMI) using sheep with various opportunities for feed selection provided by varying weighbacks between 0 and 30%. Digestible energy intakes (DEI) were also calculated. There was a slight increase in DMI values as the opportunity for selection increased, due to slightly lower DMI at low levels of weighback and higher DMI as weighback approached 30%. There were no changes in DMI due to the opportunity for selection when weighbacks varied only from 5 to 25%. Except for an apparent curvilinear relationship for the first-cut alfalfa, the change in DDM as the opportunity for selection increased was similar to that of DMI. However, the maximum changes in DDM that could be attributed to the opportunity for selection would be barely detectable in normal digestion trials. Changes in DEI attributable to the opportunity for selection were caused primarily by DMI rather than digestibility. DEI showed a slight increase as weighback increased, due to lower values at low levels of weighback and, in some cases, higher values at higher levels of weighback. There were no changes in DEI values that could be attributed to the opportunity for selection when weighbacks varied only from 5 to 25%. The data indicate that, for forage evaluation purposes, DMI and DDM can be assayed with confidence at levels of weighback between 5 and 20%.
EFFECTS OF DIETARY PROTEIN AND CELLULOSE CONTENT OF SEMIPURIFIED DIETS ON VOLUNTARY FEED INTAKE AND DIGESTIBILITY BY SHEEP
Authors: JONES G. M. , CECYRE A. , GAUDREAU J. -M.
Published: March 2010

Semipurified diets varying in dietary protein (5, 10, 15, and 20%) and cellulose (7, 14, 21, and 28%) content were fed to sheep to determine the influence of these dietary variables on voluntary feed intake (VFI) and digestibility of nutrients. Dietary protein content did not affect digestibility of dry matter (DM) or energy. Apparent digestibility of protein and nitrogen retention, but not true digestibility of protein, were directly related to protein content of the ration. VFI of the low protein diet was less than that of the 15% protein diet (P < 0.05). DM and energy digestibilities were lower (P < 0.01) for the two higher cellulose diets but there was a trend for increased VFI so that digestible energy intakes were similar. The results suggest that reduced VFI of low quality feedstuffs is related to protein content of the ration but not to dietary cellulose content per se.
RELATIONSHIP BETWEEN DIETARY PROTEIN CONTENT AND PLASMA AMINO ACIDS IN SHEEP FED PURIFIED DIETS
Authors: CECYRE A. , JONES G. M. , GAUDREAU J.-M.
Published: March 2010

Semipurified diets, varying in crude protein (CP) content (6, 10, 15, and 22% CP), were each fed to one wether and plasma amino acid (PAA) concentrations were determined at 0, 15, 30, 60, 120, 240, and 360 min postfeeding. Total essential amino acid concentrations for the 6, 10, and 15% CP rations were 47.2, 76.4, and 72.9 μmol/ml, while nonessential amino acids totalled 88.3, 110.0, and 104.9 μmol/ml, respectively. In general, PAA concentrations were depressed by the low protein diet, except for glycine, which was elevated, and threonine and alanine, which were not affected. PAA concentrations gradually decreased with time after feeding. There was no evident relationship between PAA levels and amount of feed consumed at these time intervals. Lysine was probably the most limiting amino acid, based upon PAA concentrations on the low protein diet compared to average PAA levels for all diets. PAA concentrations reflected dietary nitrogen content. The results suggest that PAA levels were not involved in the regulation of voluntary intake when the diet contained sufficient protein to meet the requirements of the animal.
SUFFICIENCY OF CU AND ZN IN BARLEY, FORAGE, AND CORN SILAGE RATIONS AS MEASURED BY RESPONSE TO SUPPLEMENTS BY BEEF CATTLE
Authors: PRINGLE W. L. , DAWLEY W. K. , MILTIMORE J. E.
Published: March 2010

Beef heifers of 232 and 205 kg average beginning weight, fed individually in a barn in two separate trials, were assigned at random to the following treatments: (A) basic barley–hay ration containing 3–1 ppm Cu and 25–32 ppm Zn; (B) basic ration supplemented to 11–12 ppm Cu; (C) basic ration supplemented to 63–66 ppm Zn. The Cu-supplemented ration resulted in an increased amount of Cu in the liver (P < 0.01). The Zn-supplemented ration resulted in a decreased amount of Cu in the liver in trial 1 (P < 0.05) but did not affect the level of Zn either in the liver or in the hair. No difference was found in average daily gain, feed consumption, efficiency of gain, or dressing percent of the heifers. It was shown that under a full-feed regime for 134 and 151 days, young animals (heifers) with Cu levels in the liver of 100 ppm or more on a dry weight basis can maintain normal metabolic balance when their ration is less than 4 ppm Cu and 33 ppm Zn. Barley and forage grown on Grey Wooded soil of the Peace River area, even though analytically low in Cu and Zn, are sufficient for heifers on full feed. In a third trial, beef steers were fed for 112 days on corn silage fortified with urea. Copper glycinate injections showed no effect on gain, although final concentrations of Cu in the liver were increased from 28 to 133 ppm on a dry weight basis. The corn silage contained 7 ppm Cu and had a Cu/Mo ratio of 6:6. Copper supplementation of corn silage rations is not warranted with this level of copper and a favorable Cu/Mo ratio.
A COMPARISON OF CORN, GLENLEA, PITIC 62, AND NEEPAWA WHEATS IN BROILER DIETS
Authors: GARDINER E. E.
Published: March 2010

A factorial experiment lasting 4 wk and using day-old broiler crossbreds was conducted to compare corn (Zea mays), Glenlea, Pitic 62, and Neepawa wheat (Triticum aestivum L.) as ingredients in broiler diets. Four levels of protein (calculated at 18.0, 20.0, 22.0, and 24%) were used with each of the four grains. Each of the 16 diets was fed to 4 replicates of 10 chicks each. The diets were so formulated that at all four protein levels protein from wheat made up a higher percent of the total dietary protein than did protein from corn in the corn diets. There was a significant difference (P < 0.01) in 4-wk body weight due to dietary protein levels, which resulted from chicks fed the 18% protein diet having lower body weights than chicks fed the other three protein levels. The grain source also significantly (P < 0.01) affected growth, with corn and Pitic 62 being inferior to Glenlea and Neepawa. The level of protein was the only criterion that significantly (P < 0.01) influenced feed-to-gain ratio, the 18% protein diets giving the poorest efficiency.
INORGANIC PHOSPHORUS, ORGANIC PHOSPHORUS, AND INORGANIC CALCIUM IN BLOOD PLASMA FROM TWO BREEDS OF CHICKENS FED VARIOUS LEVELS OF DIETARY CALCIUM AND PHOSPHORUS
Authors: GARDINER E. E.
Published: March 2010

Male crossbred broiler-type and Single Comb White Leghorn (SCWL) chickens were fed graded levels of dietary calcium (0.0, 0.3, 0.6, 0.9, 1.2, and 1.5% added) and phosphorus (0.18 and 0.36% added) from hatching to 4 wk of age. Inorganic phosphorus (PPi), inorganic calcium (PCai), and organic phosphorus (PPo) were determined on blood plasma obtained when the chickens were 4 wk old. PCaiwas influenced by breed, phosphorus, calcium, breed × calcium, and phosphorus × calcium. PPiwas influenced by the dietary level of phosphorus and calcium and a significant (P < 0.01) phosphorus × calcium interaction occurred. The dietary calcium level had a significant (P < 0.05) effect on PPoand there was a highly significant (P < 0.01) breed × calcium interaction. Regression coefficients were determined for PCaion PPi, PCaion PPo, and PPion PPousing individual data from the 24 groups and by dietary calcium levels (six groups). Few significant regressions were obtained using the individual data from the 24 groups or the data pooled by calcium levels (six groups). The most important significant regression appeared to be between PCaiand PPiat the lowest dietary calcium level.
CHEMICAL, PHYSICAL, AND NUTRITIONAL CHARACTERISTICS OF DIFFERENT SAMPLES OF WHEAT
Authors: MARCH B. E. , BIELY JACOB
Published: March 2010

Thirty-three samples of wheat (Triticum aestivum L.) were assessed on the basis of physical and chemical analysis, protein quality and quantity, and metabolizable energy. None of the values, or combination of values, from the physical and chemical analyses showed significant correlation with metabolizable energy values. Biological tests demonstrated variations in the nutritive quality of the protein in the different wheats. The diets in which the samples of wheat were incorporated were formulated to contain different levels of protein and different proportions of wheat protein and soybean protein to stress in a variety of ways the pattern of available amino acids provided by the wheat protein. A significant response was obtained from lysine supplementation to different cultivars of wheat. Nevertheless, lysine was not always the primary limiting amino acid for growth, despite a consistent improvement in feed efficiency from lysine supplementation. No consistent difference was found in the nutritional quality of protein from wheats containing different levels of protein. Further tests of protein digestibility and amino acid analyses of various cultivars of wheat may explain the varietal differences in biological response.
EFFECTS ON BROILER PERFORMANCE OF USING HEATED FLOORS FOR REARING IN A LITTERLESS ENVIRONMENT
Authors: PROUDFOOT F. G. , GUNN J. D. , ALLABY S. F.
Published: March 2010

Two experiments involving 4,400 broilers were conducted to evaluate the feasibility of rearing broilers on a heated litterless floor compared with rearing broilers under a conventional brooder with planer shavings over a concrete floor. The results of these experiments provide evidence that it is feasible to use a hot-water-heated floor, using either iron or plastic pipe, to provide heat for growing broilers without the use of litter materials.
FACTORS AFFECTING THE NUMBER AND USE OF BULL CALVES FROM ONTARIO DAIRY FARMS
Authors: CORE J. E. , STONE J. B. , BURGESS T. D. , WRIGHT P. A.
Published: March 2010

A 1971 mail survey of a sample including 924 Ontario dairy farmers was conducted to gather information on the use of dairy bull calves born on their farms. Factors affecting the breeding programs (dairy × dairy, beef × dairy, or both) on these farms were investigated, along with the factors affecting the number of bull calves raised (89,800) versus sold (111,900) from these farms. Three types of producers were considered: group I or fluid milk shippers; group II or manufactured milk shippers; and cream producers. It is shown that the type of breeding program used by Ontario dairy farmers (beef or dairy bulls), the type of calves born (dairy or crossbred), the number of dairy bull calves raised versus sold, the use for which dairy bull calves are raised on the home farm, and the destination of dairy bull calves sold are dependent on: (1) type of producer; (2) region of group I production; (3) production level of group I producers; (4) region of group II production; and (5) production level of group II producers. The number of producers raising versus selling these calves was dependent only on factors (1) and (4).
POTASSIUM AND SODIUM BALANCES DURING DIETARY POTASSIUM RESTRICTION IN SHEEP
Authors: COWAN T. K. J. , PHILLIPS G. D.
Published: March 2010

The inputs and outputs of potassium (K) and sodium (Na) were measured in six lambs prior to and during a 4-day period of acute dietary K restriction. During the predepletion period, urinary K accounted for 60.4% of the total K excreted. Renal K and Na excretion decreased during the initial stage of K restriction. Renal K excretion then continued to decrease and reached a minimum level after 40 h of K restriction, whereas fecal K excretion decreased only moderately from predepletion levels. A transient natriuresis, which occurred concurrently with the minimum level of urinary K, supported the hypothesis of the existence of a renal peritubular Na–K exchange mechanism. The delay in renal K conservation mechanisms, together with an obligatory fecal K excretion, caused an acute K deficit, estimated at 6.7–11.4%, in lambs fed a low K diet (0.032% K) for 4 days.
LEVEL OF VANILMANDELIC ACID IN EXCRETA OF PULLETS AND LAYING HENS: THE ROLE OF STRAIN, AGE, AND TIER ALLOCATION
Authors: STEFANOVIC M. P. , HURNIK J. F. , BROWN R. G.
Published: March 2010

Two age-groups from two commercial strains of laying hens were individually allocated into two tiers of single cages. Twenty-four-hour excreta were collected from all birds for vanilmandelic acid (VMA) analysis. Significant differences in absolute levels of VMA excreted were found between the two age-groups. When the ratio VMA to body weight was considered, both age-groups differed only negligibly in their VMA excretion. The factors of strain and tier level did not affect VMA output. In laying hens, the relationships between VMA and egg production and between VMA and excreta weight were nonsignificant.
FATTY ACIDS AND STEROIDS AFFECTING FLAVOR AND AROMA OF MEAT FROM RAM, CRYPTORCHID, AND WETHER LAMBS
Authors: VESELY J. A.
Published: March 2010

Organoleptic tests of meat and fat samples from 33 ram, 37 cryptorchid, and 31 wether lambs showed no significant differences in flavor or aroma among the three sex types. There was, however, a small variation in flavor and aroma among the animals. Analyses of variance of flavor and aroma scores revealed that there was a larger Variation within animals (between judges) than that between animals and the repeatability estimates for the two traits were 0.10 and 0.03. However, a significant (P < 0.01) multiple regression of flavor on 15 independent variables (six fatty acids and nine steroids) was determined and its multiple correlation coefficient was 0.56. The reduction in residual variance due to stearic acid was significant (P < 0.05) and linoleic acid was the best predictor of flavor as a single independent variable (P < 0.10). Simple correlation coefficient between flavor and aroma was estimated to be negative and nonsignificant, −0.12.
A SIMPLE MECHANICAL METHOD FOR RECOVERY OF BOVINE BLASTOMERES
Authors: KANAGAWA H. , BASRUR P. K.
Published: March 2010

not available
EFFECTS OF DIETARY UREA LEVEL ON AMINO ACID CONCENTRATIONS IN RUMINANT TISSUES
Authors: SALEM H. A. , DEVLIN T. J. , INGALLS J. R. , PHILLIPS G. D.
Published: March 2010

The effects of a semipurified diet containing 0 (0% urea-N diet), 50 (39% urea-N diet), or 100% (76% urea-N diet) of added dietary nitrogen (N) as urea on the amino acid concentrations in ruminant tissues was investigated. Three rumen-fistulated bull calves averaging 240 kg were used in a latin square design. The calves were fed using a continuous feeder to provide 7 kg of feed daily. Each experimental period of the latin square was 40 days divided into four 10-day intervals. Liver samples were obtained on the 9th day of each 10-day interval and rumen epithelium and rumen microorganisms were obtained on the 10th day of each 10-day interval. Blood samples were collected on the 6th, 8th, and 10th day of each 10-day interval for the determination of plasma amino acid patterns as well as the amino acid concentrations in the tissues. Plasma amino acid patterns indicated that when the 76% urea-N diet was fed the levels of aspartic acid, citrulline, glutamic acid, glycine, and proline were increased. Most of the essential amino acids were decreased on the 76% urea-N diet as compared with the 0% urea-N diet. All amino acids of rumen microorganisms were increased on the 39% urea-N diet with the exception of arginine, lysine, and threonine, which decreased slightly or did not show any change. Most amino acids were lower on the 76% urea-N diet as compared with the 39% or 0% urea-N diets. All essential amino acids measured in the liver were reduced on the 76% urea-N diet. Cystine, glutamic acid, glycine, isoleucine, leucine, lysine, tryptophan, and valine were also reduced on the 39% urea-N diet. In rumen epithelium, there was a reduction of the essential amino acids and an increase of the nonessential amino acids on the 76% urea-N diet.
VOLUNTARY ROUGHAGE INTAKE BY NONPREGNANT AND PREGNANT OR LACTATING BEEF COWS
Authors: JORDAN W. A. , LISTER E. E. , WAUTHY J. M. , COMEAU J. E.
Published: March 2010

Pregnant and nonpregnant Shorthorns were group-fed either hay or grass silage ad libitum from December until midsummer in 2 successive yr. Stage of gestation at the start of feeding each year averaged 120 days. In the 1st yr the cows were housed and in the 2nd they were confined to outside paved lots. Until the start of calving, the pregnant groups tended to consume less than their nonpregnant counterparts. During the 2 wk before the start of calving this difference in intake between pregnant and nonpregnant cows increased up to 12%. However, it was only for the silage-fed, pregnant cows wintered outside that intake was clearly insufficient for maintenance up to 48 h postcalving. Depsite a rapid increase in postcalving intake, all lactating groups lost weight. Results indicated that pregnancy in beef cattle may reduce intake below that expected from nonpregnant animals and may result in insufficient forage consumption for maintenance. During early lactation, beef cows were unable to consume enough stored forage to meet their full energy requirements.
USE OF STEAMED ASPEN POPLAR IN A FINISHING RATION FOR HOLSTEIN STEERS
Authors: HEANEY D. P. , LISTER E. E. , BENDER F.
Published: March 2010

not available
INFLUENCE OF RAPESEED PRODUCTS ON EGG QUALITY AND LAYING HEN PERFORMANCE
Authors: LESLIE A. J. , PEPPER W. F. , BROWN R. G. , SUMMERS J. D.
Published: March 2010

Diets containing 20% rapeseed meal, 20% full-fat rapeseed, and 3 or 10% rape-seed oil were fed to White Leghorn hens to study their effects on egg quality and hen performance. The 10% rapeseed oil group and the 20% rapeseed group resulted in egg production that was significantly below that of the control corn–soya diet. Feed consumption was reduced with the 20% rapeseed and 20% rapeseed meal diet as well as with the high oil diet. Egg size was reduced by 20% full-fat rapeseed and 10% rapeseed oil. Shell deformation was significantly reduced with 20% dietary rapeseed meal or 20% full-fat rapeseed. Shell thickness, on the other hand, was improved by 3% rapeseed oil but adversely affected by 10% rapeseed oil. Haugh units were improved by 20% full-fat rapeseed or 3% rapeseed oil. A taste panel consistently gave eggs from the 10% oil group a lower score than any of the other treatment groups, but no distinct flavor or odor could be detected. Fat composition values indicated that something in rapeseed, other than the oil, was resulting in a more unsaturated egg yolk fat from hens fed this product.
EFFECTS OF DIFFERENT DRY MATTER DETERMINATION METHODS ON CHEMICAL COMPOSITION AND IN VITRO DIGESTIBILITY OF SILAGES
Authors: LARSEN R. E. , JONES G. M.
Published: March 2010

Dry matter (DM) contents of 13 silages, comprised of 5 corn, 4 legume–grass, and 4 corn–hay crop silage mixtures, were determined by (1) toluene distillation (TD), corrected for volatiles lost into the aqueous distillate; (2) TD, uncorrected; (3) freeze-drying (FD); (4) oven-drying (OD) at 40 C; (5) OD at 65 C; and (6) moisture-tester at 100 C. Corrected TD showed significantly higher (P < 0.01) DM levels compared with other methods. Up to 12.8% loss of DM resulted from heat-drying, depending on the method and the sample. Dried-ground silages were analyzed for nutrient composition. No significant changes in cell-wall constituents or organic matter contents were observed. Silages that were FD were highest in cellulose content (P < 0.05), whereas both FD and OD at 40 C resulted in significant increases in gross energy (P < 0.05) and crude protein (P < 0.01) content compared with other methods. FD or OD at 40 C resulted in the highest dry matter solubility and in vitro digestibility of cellulose, dry matter, and organic matter (P < 0.05). The lowest values for these analyses were obtained with silages heat-dried at 65 and 100 C. Results of these studies suggest that corrected TD should be used for determination of silage DM content and that in vitro analyses or other biochemical determinations should be conducted on silage samples that have been freeze-dried or oven-dried at 40 C.
SELECTION INDEXES WITHOUT ECONOMIC WEIGHTS FOR ANIMAL BREEDING
Authors: BAKER R. J.
Published: March 2010

The expected responses of five methods of constructing selection indexes without using economic weights were compared by application to data on growth rate and feed efficiency in swine. One method based on the product of phenotypic values as an index can be used when no estimates of genetic and phenotypic parameters are available and when the breeder considers all traits to be of nearly equal importance. A second method using ’desired gains’ allows the breeder to specify that different traits are of different importance without doing so in economic terms. The remaining three related methods, based on the principles of multivariate statistics, were judged unsatisfactory for most animal breeding programs.
FACTORS INFLUENCING THE GROWTH OF LAMBS REARED ARTIFICIALLY OR WITH THEIR DAMS
Authors: PETERS H. F. , HEANEY D. P.
Published: March 2010

Over a 3-yr period, weights of 236 lambs reared artificially with liquid plus solid diet from 2 to 70 days and 298 lambs creep-fed a solid diet and reared with their dams from birth to 70 days were recorded at birth, 35, 70 and 140 days of age. Included were 400 lambs of the Suffolk (SU) and Shropshire (SH) breeds and their reciprocal crosses and 134 lambs of the Ottawa (MM) synthetic strain. There were significant interactions of rearing system with year (P < 0.01) in growth rate up to 140 days of age, and with breed of lamb (P < 0.01), sex (P < 0.05) and type of birth (P < 0.01) up to 70 days. Ram lambs gained more than ewe lambs, but the difference was less in artificial rearing. Singles gained more (P < 0.01) than twins up to 70 days when reared with their dams, but not when reared artificially. Significant (P < 0.01) age of dam effects on body weight persisted up to 70 days for lambs reared artificially and up to 140 days for lambs reared with their dams. The overall mean 140-day weights did not differ significantly in the two systems. Breed means and standard errors of 140-day wt for lambs reared artificially and for lambs reared with their dams were, respectively: MM, 29.7 ± 1.08 and 29.7 ± 0.96 kg; SU, 29.9 ± 1.08 and 32.7 ± 0.95 kg; SH, 24.1 ± 1.31 and 26.2 ± 1.14 kg; SU (sire) × SH (dam), 31.0 ± 1.30 and 30.7 ± 1.08 kg; and SH × SU, 28.9 ± 1.20 and 32.8 ± 1.03 kg.
FATTY ACID COMPOSITION OF PORCINE DEPOT FAT AS RELATED TO THE EFFECT OF SUPPLEMENTAL DIETARY COPPER ON THE SPECIFIC ACTIVITIES OF FATTY ACYL DESATURASE SYSTEMS
Authors: HO S. K. , ELLIOT J. I.
Published: March 2010

Copper supplementation of a swine diet (barley-wheat-soybean meal) at a level of 250 ppm was associated with improved average daily gain, reduction in the melting point of the depot fat, increase in liver copper, decreased proportions of stearic and palmitic acids and concomitant increases in proportion of the medium-chain myristic acid as well as those of the major long-chain unsaturated fatty acids in the depot fat, and increases in the capacities of hepatic and adipose microsomes to desaturate 1-14C-oleate (in the presence of coenzyme A, ATP, Mg2+) and 1-14C-palmitoyl-CoA. There were neither sex differences nor copper × sex interactions. It is suggested that supplemental dietary copper enhances the specific activities of the fatty acyl desaturase systems, and that this enhancement contributes to the observed changes in fatty acid composition of the depot fat.