bluuebunny/crossref_metadata_2025 huggingface dataset:
EFFECT OF SODIUM BICARBONATE ON NITROGEN UTILIZATION AND FEED INTAKE BY LAMBS
Authors: PHILLIP L. E.
Published: March 2010

Eight wether lambs, four equipped with rumen cannulae and four intact, were assigned to four high-concentrate diets according to a 4 × 4 double latin square with 27-day periods. The basal diet consisted of barley and corn silage, the latter representing 30% of the dry matter (DM), and was either unsupplemented (9% dietary protein) or supplemented (15% protein) with brewers' dried grains. To each of the low protein (LP) and high protein (HP) diets, sodium bicarbonate (NaHCO3) was either not added or added at the level of 4% of the diet DM. There was a marked, though not statistically significant, improvement in nitrogen retention due to NaHCO3 inclusion, particularly when protein intake was low. Voluntary feed intake increased by 11% as a result of NaHCO3 addition but the effect was nonsignificant. Bicarbonate-induced changes in feed intake were unrelated to changes in rumen pH. A maximum ruminal osmolality of 303 mOsm/kg elicited by NaHCO3 addition did not appear to restrict feed intake. Rumen ammonia concentration tended to decrease as a result of NaHCO3 addition. Digestibility of organic matter and of DM was unaffected by the inclusion of NaHCO3 but digestibility of nitrogen tended to increase. It is suggested that NaHCO3 could have a protein-sparing effect when added to protein-deficient concentrate diets, and that bicarbonate-induced changes in feed intake may be related to its influence on protein status of ruminants. Key words: Bicarbonate, buffers, lambs, nitrogen utilization, feed intake
EFFECTS OF POSTWEANING PROTEIN REGIMENS AND UREA ON THE PERFORMANCE OF INTENSIVELY REARED LAMBS
Authors: HEANEY D. P. , SHRESTHA J. N. B. , PETERS H. F.
Published: March 2010

Seven hundred fifty artificially reared lambs that had been weaned from milk replacer at 3 wk of age were randomly assigned, at weaning, to 12 ration sequences: 20% vs 17% dietary crude protein from weaning to 56 days of age, 17% dietary protein from 57 to 98 days of age and 17 vs 14% dietary protein from 99 to 140 days of age and each of the resulting four dietary protein concentration regimens with the protein being provided as natural protein throughout, with 30% of the protein being provided as urea throughout or with 30% of the protein being provided as urea from 57 to 140 days of age. The diets contained 72% corn-soybean meal, or corn-soybean-meal-urea and 20% ground hay, providing about 3 mcal/kg of digestible energy. Maximum growth performance was achieved by the lambs fed diets containing only natural protein in the concentration sequence of 20/17/17. However, the advantage (though statistically significant at a probability of 0.05) was small and slightly lower gains with the protein sequence of 17/17/14 might prove economical because of the savings in expensive protein supplement. There was generally no advantage in growth performance as a result of 17% vs 14% dietary protein after 98 days of age. The results also indicated that such lambs can adapt to, and utilize, urea but that introduction of urea should be delayed for about 2 wk after weaning to allow sufficient time for development of fully functional rumens. Key words: Lambs, protein requirements, urea, artificially reared, early weaned
HEAVY VEAL PRODUCTION WITH HOLSTEIN CALVES RAISED BY MULTIPLE SUCKLING OR MILK REPLACERS AND FATTENED WITH WHOLE CORN, BARLEY OR OATS
Authors: LATRILLE L. , PARÉ J. P. , ST-LAURENT G. , POMAR C.
Published: March 2010

Three groups of 35 Holstein bull calves were raised by multiple suckling (MS) or a milk replacer fed as such (MR) or acidified to pH 5.4 (MRA). MS calves consumed more milk and starter and gained faster (P < 0.05) than those on the other treatments. Performance of MRA calves tended (P > 0.05) to be better than MR calves except for feed efficiency. The three rations fed during the fattening phase consisted of corn (three parts) plus protein supplement (one part), or barley or oats (four parts) and supplement (one part). The effect of adding hay was tested in the corn-fed group and found not to be useful since calves fed corn without hay showed significantly (P < 0.05) higher gains and feed efficiencies. A digestibility trial indicated lower dry matter and energy digestibility coefficients by calves fed oats while starch was less well digested by the barley-fed calves (P < 0.05). Acid detergent fiber was poorly digested particularly by oat- and barley-fed calves. During fattening, corn-fed calves had higher average daily gains (ADG), were more efficient, consumed less grain and reached slaughter weights faster than barley- or oat-fed calves. Barley- and oat-fed calves consumed significantly less protein supplement, and barley-fed calves (but not oat-fed calves) produced similar carcass weights and dressing percentages to corn-fed calves. Oat-fed calves stayed longer on experiment, had lower ADG, were less efficient and produced lighter carcasses with lower dressing percentages and slightly inferior classifications. Key words: Veal calves, multiple suckling, cereal grains, digestibility
GROWTH-DEPENDENT CHANGES IN THE CONTENT OF THE COLLAGEN CROSSLINK, PYRIDINOLINE, IN JOINT CARTILAGE FROM PIGS
Authors: NAKANO T. , THOMPSON J. R. , AHERNE F. X.
Published: March 2010

The age-related changes in the content of the nonreducible collagen crosslink, pyridinoline, was studied in tibial joint cartilage obtained from pigs ranging in age from 4 wk before birth to 30 wk. Pyridinoline was found in all tissues studied. The result indicated that the content of pyridinoline in cartilage collagen increased approximately 15-fold (P < 0.01) with increasing animal age. Key words: pyridinoline, hydroxypyridinium compound, collagen crosslink, cartilage, growth, pig
EFFECT ON DAM PERFORMANCE AND FETAL DEVELOPMENT OF DEOXYNIVALENOL (VOMITOXIN) CONTAMINATED WHEAT IN THE DIET OF PREGNANT GILTS
Authors: FRIEND D. W. , TRENHOLM H. L. , FISER P. S. , HARTIN K. E. , THOMPSON B. K.
Published: March 2010

From the time of breeding at an average age of 178 days and 121 kg bodyweight, three groups of 12 gilts each were offered ad libitum one of three diets containing 70% wheat and vomitoxin levels of 0.1 (C), 1.7 (M) and 3.5 (H) ppm. The gilts, housed and fed individually, were killed between days 50 and 54 of pregnancy and the reproductive tracts and some body organs were examined. The growth rate of gilts given diet H was less (P < 0.01) than that of other gilts, probably the result of a reduced feed intake. Differences in organ weights were not significant (P > 0.05). Fetal mortality rate, although least for gilts fed diet H, was not significantly different among diets. There was a significant linear trend toward lower fetal weight, decreased fetal length and reduced osmolality of allantoic fluid with increasing vomitoxin levels which could not, in this experiment, be attributed to a direct physiological or toxicological effect of vomitoxin. Key words: Fetal pig, gilt, pregnant, mycotoxin, vomitoxin, deoxynivalenol
EFFECT OF INCREASING DIETARY FAT, CALCIUM AND PHOSPHORUS LEVELS ON PERFORMANCE AND MINERAL METABOLISM OF WEANER PIGS
Authors: ATTEH J. O. , LEESON S.
Published: March 2010

The influence of supplementing pig diets with 0, 5 or 10% fat, increasing dietary calcium and available phosphorus levels from 0.8 to 1.2% and from 0.53 to 0.8%, respectively, was investigated with 3-wk-old weaner pigs for a period of 6 wk. Average daily gain (P < 0.05) and feed intake (P < 0.01) were reduced with dietary fat supplementation. However, 10% supplemental fat in the diet caused an improvement (P < 0.05) in feed:gain ratio. Dietary calcium and phosphorus levels had no significant effect on daily weight gain, feed intake or feed:gain ratio. There was no significant effect of dietary fat or calcium and phosphorus treatment on digestibility of calcium, phosphorus or magnesium. There was also no significant difference in the pH of stomach and duodenal contents due to the dietary treatments. The rectal contents of pigs fed supplemental fat was found to be more acidic than those from the control group (P < 0.05). There was no significant effect of dietary fat, calcium and phosphorus treatments on bone or serum calcium, phosphorus or magnesium content. It is concluded that weaner pigs will tolerate high levels of fat without any detrimental effect on mineral digestibility and subsequent bone mineralization. Key words: Weaner pigs, fat, calcium, performance, bone and serum minerals
FEED PREFERENCE RESPONSES OF SEVERAL AVIAN SPECIES FED ALFALFA MEAL, HIGH- AND LOW-SAPONIN ALFALFA, AND QUININE SULFATE
Authors: CHEEKE P. R. , POWLEY J. S. , NAKAUE H. S. , ARSCOTT G. H.
Published: March 2010

The response of male geese, turkeys, Japanese quail and chickens to dietary levels of 0.5, 1, 2.5, 5, 10, 20 and 30% alfalfa meal was measured, using a two-choice feed preference test. At each alfalfa level, the birds were given a choice between the alfalfa-containing diet and an alfalfa-free diet. At levels of 10% or more alfalfa meal, all species showed a significant (P < 0.05) preference for the alfalfa-free diet. At a dietary level of 5% alfalfa meal, all species except chickens discriminated against the alfalfa-containing diet and preferred the alfalfa-free diet. Geese discriminated against the alfalfa-containing diet at 2.5% alfalfa, while no species showed discrimination at alfalfa levels of 0.5 and 1%. The birds did not discriminate between low- saponin and high- saponin alfalfa-containing diets, each compared at alfalfa levels of 1, 5, 10 and 20%. Quinine sulfate was included at levels of 0.01, 0.05 and 0.1% of the diet; discrimination against the quinine-containing diets was noted, indicating that poultry can detect substances in the diet perceived as bitter by humans. Key words: Poultry, quinine, alfalfa saponins, feed preferences
ESTIMATES OF VARIANCE COMPONENTS FOR HOLSTEIN-TYPE TRAITS
Authors: SCHAEFFER L. R.
Published: March 2010

Sire and error variances and covariances for 27 conformation traits were estimated from 424 875 Holstein-Friesian cows classified since June 1976. Estimates were obtained by Henderson's new method (Diagonal-MIVQUE) with a model that included 46 age by parity groups, 10 stage of lactation groups, herd-round-classifier effects, and nine covariates of dam's type and sire effects. Heritabilities were generally low from 0.10 for feet and legs to 0.29 for capacity, and from 0.05 for rear heel to 0.42 stature. Final class had a heritability of 0.17 and was highly correlated with traits related to mammary system (0.62–0.94). A multiple trait analysis of type could utilize the estimates from this study. Key words: Genetic parameters, type traits, Henderson's new method
RELATIONSHIPS BETWEEN SPEED OF MILKING AND SOMATIC CELL COUNT AND PRODUCTION IN HOLSTEINS
Authors: MOORE R. K. , MOXLEY J. E. , KENNEDY B. W. , BURNSIDE E. B.
Published: March 2010

Milking speed data were obtained for 2604 Holstein-Friesian cows, identified by sire, in test herds located in Quebec and Ontario. Milk samples were collected from each cow and analyzed for somatic cell count. Completed or projected lactation production records were available for this sample of cows. Two-minute yield and total milking time were adjusted for the effect of milk yield at sampling and the raw cell counts were transformed to the natural log scale. Sire and error variances were obtained by maximum likelihood (ML) methods and used to estimate heritabilities of and correlations between traits. The heritability estimate for the adjusted 2-min. yield, 0.23, was higher than that for the adjusted total milking time (0.13), with the estimates for the two unadjusted measures being intermediate (0.18). The phenotypic correlations between milking speed and somatic cell count were small. However, there were two distinct linear phases to the relationship between the adjusted 2-min yield and cell count. Small but significant phenotypic correlations were observed between unadjusted measures of milking speed and lactation production (0.11–0.22); however, correlations were not significant when adjustments were made for the milk yield at sampling. Genetic correlations between milking speed and somatic cell count were moderate to large and indicated an antagonistic relationship between faster milking speed and cell count. Also, the genetic correlations suggested some antagonism between increasing 2-min yield and lactation production, while the relationship between lactation traits and milking time was small. Key words: Milking speed, somatic cell count, correlations, heritabilities, Holsteins
THE ESTROGENIC AND ANTIESTROGENIC EFFECTS OF COUMESTROL AND ZEARALANOL ON THE IMMATURE RAT UTERUS
Authors: KITTS W. D. , NEWSOME F. E. , RUNECKLES V. C.
Published: March 2010

Coumestrol (Co) (25 μg) administered subcutaneously to 21-day-old rats caused an increase in uterine cytosolic protein, estradiol-17β (E2) receptors and progesterone (P4) receptors. A single dose of 25 μg Co resulted in nuclear retention which was quantitatively less and of shorter duration than that following treatment with 0.125 μg E2. Other uterine responses (increases in uterine weight, cytosol protein and P4 cytosol binding) were also less. When Co was administered in repeated doses over a 4-h period or fed for 3 days, uterine responses were similar to those obtained after treatment with 0.125 μg E2. When Co was administered with 0.125 μg E2 on consecutive days, the uterine responses to E2 were reduced. In this schedule, Co acted as an antiestrogen presumably by displacing the more effective estrogen from a limited number of nuclear binding sites. Zearalanol (Z) (0.5 μg) given as a single dose was retained in the nucleus for a longer period than E2 but the uterine responses were slightly less. When Z was given simultaneously with E2 in a single dose, Z reduced the effects of E2 on P4 binding sites and on cytosol protein levels. When given with E2 on two consecutive days, the estrogenic effects on E2 and P4 cytosol binding sites and cytosol protein were reduced. These studies indicate that Co and Z, which are naturally occurring estrogens of plant origin, induce many of the same biological and biochemical responses evoked by E2. Co can act as an estrogen and an antiestrogen depending on the schedule of administration. Key words: Phytoestrogens, coumestrol, zearalanol, estrogenic/antiestrogenic effects, uterus, rat
APPARENT DIGESTIBILITY AND NUTRITIONAL VALUE OF UREA OR AMMONIA-SOLUTION-TREATED CORN SILAGES FOR LACTATING HOLSTEIN COWS AND MATURE SHEEP
Authors: BAREEBA F. B. , INGALLS J. R. , McKIRDY J. A. , SHARMA H. R.
Published: March 2010

Corn silages were treated at harvest with 0.5% urea or 1.3–2.2% ammonia-molasses-mineral solution. Apparent recoveries of added nitrogen in the corn silages ranged from 95 to 100% in both experiments. Water-insoluble N and lactic acid contents were increased in the treated silages as compared to the control. Four diets containing either (1) grass-legume (GL) silage (38% DM) + medium grain (MG); (2) 0.5% urea-treated corn (CU) silage (31% DM) + MG; (3) 2.2% ammonia-treated corn (AC) silage (32% DM) + MG; (4) AC silage + low grain (LG) were fed to eight Holstein cows in a latin square design. Silage DM consumption, milk production and milk composition were not different (P > 0.05) among treatments. Reducing the level of grain feeding from 32 to 23% of the diet with ammonia-treated corn silage resulted in a decrease (P < 0.05) in total DM consumption, with no apparent effect on milk production or composition, at the levels of production observed in this study. There were significant (P < 0.05) differences among treatments in molar percentages of acetic, propionic and butyric acids in rumen fluid. However, no differences were observed in milk fat or solid nonfat contents of the cows receiving the four experimental diets. Sheep digestion studies carried out on the above silages indicated apparent digestibilities of DM, CP and energy were lower (P < 0.05) for the GL silage compared with the UC or AC silages (exp. 1), whereas there were no differences in apparent digestibilities of DM and energy of untreated corn silage or NPN-treated silages (exp. 2). However, crude protein digestion coefficient was lower (P < 0.05) for untreated corn silage compared with the three NPN-treated corn silages. The present studies failed to show a beneficial effect of treating corn silage with an ammonia, molasses and mineral solution rather than urea on silage fermentation and animal performance. Key words: Dairy cows, sheep, nitrogen balance, ammonia treatment, corn silage
FORTIFICATION OF CALF MILK REPLACERS WITH AMINO ACIDS IN FREE FORM OR PLASTEIN-BOUND
Authors: JENKINS K. J. , EMMONS D. B.
Published: March 2010

Calves (eight per lot), from 3 to 45 days of age, were fed milk replacer containing skim powder, whey, and soy protein; or skim powder, whey, and blood protein; or skim, whey control diet. Additional treatments included supplementation of the soy and blood diets with the calculated-limiting amino acids (CLAA) either in the free form, or bound to the soy or blood proteins by the plastein reaction in an attempt to enhance utilization of the supplemental amino acids. Supplementation of the soy and blood basal diets with either free or plastein-complexed CLAA increased average daily gain (ADG), feed intake, and feed efficiency, with the free and plastein-bound CLAA giving approximately the same improvements. Additionally, the low blood plasma levels of CLAA for the soy and blood protein basal groups were increased to a similar extent by supplementation with free or plastein-bound CLAA. Only the skim milk control diet clotted, in vitro, on addition of rennet (pH 6.1). It is suggested that the plastein-bound and free, supplemental CLAA gave similar improvement in calf performance either because all sources of amino acids were absorbed at similar rates, or alternatively, because the calf does not require absorption of all essential amino acids at closely similar rates for efficient utilization in body protein synthesis. Key words: Calves, milk replacers, plastein
THE EFFECT OF LACTOBACTERIA INOCULATION ON CORN SILAGE PRESERVATION AND FEEDING VALUE FOR GROWING BEEF ANIMALS AND LAMBS
Authors: WITTENBERG K. M. , INGALLS J. R. , DEVLIN T. J.
Published: March 2010

The effect of a commercial lactic acid bacteria inoculant, Sila-bac, on nutrient preservation and nutritional value of corn silage was evaluated. In this study, addition of inoculant to corn forage at a rate of 0.6 kg/tonne under good ensiling conditions did not improve (P > 0.05) the preservation of dry matter, crude protein, acid detergent fiber or gross energy. Lactic acid concentrations and pH levels were similar, being 2.26 and 2.02; and 4.0 and 3.9 for the control and silages treated with L. plantarum, respectively. Inoculated silage fed with a grain-based supplement resulted in similar feed intakes, average daily gains and feed efficiencies in growing cattle as did the untreated corn silage fed with the same supplement. A digestibility and nitrogen balance study was conducted with eight growing lambs using a 4 × 4 double latin square design. Dietary treatments were (A) control corn silage plus barley-soybean meal (SMB) supplement, (b) inoculated silage plus barley-SBM supplement, (C) control silage plus barley-urea supplement and (D) control silage plus SBM-urea supplement. Actual dietary crude protein levels for these diets were 11.4, 11.8, 11.1 and 13.0% (100% DM basis). Dietary treatment did not influence nutrient digestion (P > 0.05). Total rumen volatile fatty acid concentrations were depressed (P < 0.05) for lambs fed the barley-urea supplement compared with those fed the high protein diet. A nitrogen balance study indicated no difference (P > 0.05) in nitrogen retention for lambs receiving the control or the inoculated silage. Nitrogen retention was reduced (P < 0.05) for lambs fed the barley-urea supplement along with corn silage. Key words: Lactobacillus inoculant, corn silage, beef cattle, sheep
EFFECTS OF PRESERVING ALFALFA FORAGE AS FORMIC-ACID-TREATED SILAGE, WILTED SILAGE, AND AS HAY IN LARGE ROUND BALES ON CHEMICAL COMPOSITION, RECOVERY OF NUTRIENTS, DIGESTIBILITY AND HEIFER GROWTH
Authors: ATWAL A. S.
Published: March 2010

First-cut alfalfa was stored as formic-acid-treated silage (FS), wilted silage (WS) and hay (Hay 1) in large round bales (LRB). Hay 1 was exposed to frequent showers (15.1 mm) in the windrows and required a drying period of 13 days; dry matter (DM) yield was only 60% of the average for silages (3.9 tonnes/ha). Second-cut alfalfa hay (Hay 2) yielded 1.84 tonnes DM/ha. For winter feeding, recoveries from storage of FS, WS, Hay 1 and Hay 2, respectively, were 85.7, 87.2, 78.3 and 81.9% of energy; 81.1, 87.0, 75.0 and 72.6% of crude protein (CP). Adlibitum intakes of DM were 1.90, 1.93, 1.78 and 2.08% of body weight for the four treatments, respectively. Differences in chemical composition and digestibility of nutrients for FS, WS and Hay 2 were small and statistically not significant (P > 0.05). However, values of FS were highest for CP (20.6%) and gross energy (20.5 kJ/g DM); digestibilities of DM, energy and CP (i.e. 59.3, 60.6 and 68.7% respectively) when fed at maintenance level; digestibilities of DM, energy, CP, cellulose and hemicellulose (i.e. 64.1, 66.6, 61.9, 64.5 and 46.3%, respectively) when fed in combination with corn silage (1:1 DM basis) on an ad libitum basis. All these values were significantly (P < 0.05) higher than the corresponding values for Hay 1. Heat damage to CP of hay stored in LRB was high and 19.9% of total N of Hay 1 was in the acid detergent insoluble fraction. In a growth study, performance of yearling heifers did not differ significantly when rations made of corn silage and FS or WS (1:1 DM basis) were compared. Key words: Alfalfa silages, wilted, digestibility, formic acid, round bales, heifer growth
CHEMICAL COMPOSITION AND NUTRITIVE VALUE OF BUCKWHEAT CULTIVARS FOR LABORATORY RATS
Authors: THACKER P. A. , ANDERSON D. M. , BOWLAND J. P.
Published: March 2010

Experiments were conducted to determine the nutritive value of selected buckwheats in comparison with common buckwheat or tartary buckwheat. A 21-day, growth trial was conducted in which 42 Spraque-Dawley rats (initial weight 57 g) were randomly assigned to one of seven dietary treatments. Experimental diets contained the buckwheat cultivars, Mancan, Tempest and Tokyo, two unselected forms of common buckwheat (common and CM 169), tartary buckwheat or a casein control. Diets were formulated to supply 10% crude protein by dilution of the test protein with varying levels of a basal diet. An additional 36 rats were utilized in digestibility studies. There was little difference in chemical composition, mineral content, level of indispensable amino acids or digestibility coefficients between selected and unselected varieties of common buckwheat, while tartary buckwheat had lower levels of crude protein, lower indispensable amino acids, higher acid detergent fiber levels and lower apparent digestibility coefficients for dry matter, crude protein and energy. Weight gain and feed conversion efficiency were significantly (P < 0.05) improved for rats fed the selected varieties of buckwheat in comparison with those fed the common or tartary buckwheat. The overall results suggest that the selected cultivars of common buckwheat will support improved animal performance. Key words: Buckwheat, rats, nutritive value, digestibility
EFFECT OF FEEDING POULTRY DIETS SUPPLEMENTED WITH RAPESEED MEAL AS A PRIMARY PROTEIN SOURCE TO JUVENILE AND ADULT MEAT BREEDER GENOTYPES
Authors: PROUDFOOT F. G. , HULAN H. W. , McRAE K. B.
Published: March 2010

A factorial experiment was conducted, with a total of 3168 birds from four commercial meat parent genotypes, to study the cumulative effects of feeding soybean meal (SM) and rapeseed meal (RSM) as protein sources in both juvenile and adult breeder diets. Averaged over all genotypes, general performance was equivalent for all combinations of SM and RSM in the juvenile and adult diets although there was some evidence of second order interactions involving genotypes with juvenile and adult dietary combinations. These interactions affected egg production and related traits such as feed efficiency. It was concluded that some genotypes exhibit a greater responsiveness to rapeseed meal diets than others and that juvenile and adult diets using a combination of different sources of dietary protein supported equal or better performance compared with the same dietary protein source used throughout both periods. Key words: Meat breeders, rapeseed meal, canola, poultry, diets
PORCINE IMMUNOGLOBULIN-FORTIFIED MILK REPLACERS FOR NEWBORN LOW-BIRTH-WEIGHT PIGS
Authors: WHITING R. , OWEN B. D. , BEAMES R. M. , ELLIOT J. I.
Published: March 2010

Three experiments were carried out to test, under commercial conditions, the artificial rearing of low-birth-weight (< 0.9 kg) pigs from birth, and incorporation of immunoglobulins in the diet to enhance their survival rate. The results confirmed that the provision of dietary immunoglobulin on the first day after birth has a beneficial effect similar to that of colostrum, but that the feeding of immunoglobulins should continue to at least 21 days of age to maximize survival. Key words: Piglet, artificial rearing, immunoglobulin, colibacillosis
VISCERAL CHARACTERISTICS OF THREE BREEDS OF SWINE AND THEIR CROSSES
Authors: McKAY R. M. , REMPEL W. E. , CORNELIUS S. G. , ALLEN C. E.
Published: March 2010

Two hundred and forty-nine pigs representing all possible two-breed crosses of Minnesota no. 1 (M), Pietrain (P), and Yorkshire (Y) breeds were slaughtered over five developmental stages (35 days of age, 22.5 kg, 45.0 kg, 67.5 kg, and 90 kg liveweight). The objectives were to determine how reciprocal differences and heterosis were affected by advancing maturity, to examine breed differences, and to determine growth curves for certain visceral measurements. Reciprocal differences were observed to show two distinct patterns. The first was characterized by an increase in magnitude relative to stage of development and the second was parabolic. Statistically significant heterosis estimates for these traits were the exception rather than the rule. The following breed differences were found: M > P > Y for large intestine length and leaf fat weight, (M = Y) > P for liver weight, P > Y > M for spleen weight, M > (P = Y) for kidney weight, M > Y > P for stomach weight and M > (P = Y) for small intestine wet weight. The growth curves for the viscera indicated that the intestinal tracts were the first to complete their growth, the internal organs grew relatively slower than liveweight increased, and the majority of leaf fat deposition occurred as the animals approached 90 kg live-weight. Key words: Reciprocal differences, heterosis, breed differences, viscera, growth curves, pigs
CONSUMER ACCEPTANCE OF FRESH PORK AND PORK PRODUCTS FROM LITTERMATE BOARS AND BARROWS
Authors: CLIPLEF R. L. , GRINWICH D. L. , CASTELL A. G.
Published: March 2010

Forty-six littermate boars and barrows of both Lacombe and Yorkshire breeding were fed a 16% protein diet from weaning to slaughter at 90 kg. Pigs were killed at a local abattoir, and fresh products were processed at the Research Station Meats Laboratory. Hams and bacon were cured and smoked at a local abattoir. Forty-eight families received analogous samples of ham, bacon, sausage, fresh roasts and fresh pork chops from both boars and littermate barrows. Families rated the cooked samples for odor, flavor and tenderness and indicated their preference as well as their reason for preference. There were no significant differences in organoleptic scores for any of the products tested but consumers preferred products from barrows more often than products from boars. Boars had higher levels of 5α androstenone in loin fat and significantly higher levels in ham fat (P < 0.01). Levels of androstenone in ham fat did not differ significantly after processing (curing and smoking). Boar bacon shrank significantly more (P < 0.01) and boar hams significantly more (P < 0.05) during processing than those of littermate barrows. Key words: Consumer acceptance, consumer preference, barrow, boar pork, androstenone
THE EFFECT OF FEED RESTRICTION ON FEED EFFICIENCIES AND CARCASSES OF CHAROLAIS × HEREFORD STEERS
Authors: HIRONAKA R. , SONNTAG B. H. , KOZUB G. C.
Published: March 2010

Eighty Charolais × Hereford steer calves averaging 253 kg were fed an all-concentrate diet in amounts to allow gains of about 0.7 kg per day (L) or 0.9 kg per day (M), or were given the diet ad libitum to permit a high rate of gain (H). The feeding levels were arranged to provide five feeding programs of LLH, LMH, HML, MMM, and HHH, with each of the first two periods of 12-wk duration and a final period that varied in length because steers were marketed as they reached about 520 kg. The steers fed on the HHH program consumed the most feed per day, gained the fastest, and required the least time to reach market weight. The digestible energy requirement of 109.4 MJ/kg gain for the HHH steers was similar to that of steers on the LLH program and only marginally greater than that of steers on the LMH, HML, and MMM programs. Steers that were restricted in feed intake during part or all of the experiment had leaner carcasses than those that were given the diet ad libitum throughout. All carcasses of steers that were restricted in feed during part or all of the feeding period graded A1 or A2, whereas 25% of the steers fed ad libitum throughout the feeding period graded A3. An economic comparison was made using combinations of low and high grain to forage price ratios and small and large price differentials between A2 and A3 carcass grades. The LMH program ranked first in net returns, the MMM program ranked second under two economic situations, and the HHH ranked second under two other economic situations. Key words: Feed restriction, carcass, steers, LP model
AN EVALUATION OF FENVALERATE (BOVAID) EARTAGS AS AN IMPROVEMENT IN FLY CONTROL METHODS FOR INCREASED MILK PRODUCTION IN DAIRY HERDS
Authors: BURTON J. H. , McMILLAN I. , SURGEONER G.
Published: March 2010

A field study was conducted on 60 cooperating dairy farms in Southwestern Ontario to determine the effect of fenvalerate-impregnated (8% wt/wt) eartags (Bovaid (Registered trademark CIBA-GEIGY Canada Ltd.)) on fly control and milk production. Herds were assigned to either a tagged or control treatment. Fly counts were made on 15 randomly selected cows in each herd at approximately 2-wk intervals from July to September. Producers of control herds in this study conducted normal management practices including, in most cases, conventional fly control methods. Therefore, the comparison in this study is between the fenvalerate-impregnated tag and more conventional means of fly control. Milk production data were obtained from DHIC and Ontario Milk Marketing Board records. The use of the Bovaid tag resulted in complete control of horn flies (Haematobia irritans) and a 75% reduction in face flies (Musca autumnalis) over the test period. Milk production was not significantly affected by treatment although a 2–3% improvement was observed in treated animals. A milk production effect of 7% would be required for statistical significance (P < 0.05). Key words: Fenvalerate, ear tags, fly control, milk production
GROWTH RESPONSE OF BEEF CATTLE AT PASTURE TO ZERANOL OR PROGESTERONE-ESTRADIOL IMPLANTS
Authors: BASARAB J. A. , GOULD S. R. , WEISENBURGER R. D.
Published: March 2010

Forty-eight field trials were conducted in 1980 and 1981 on 38 commercial beef herds to determine the effectiveness of zeranol (36 mg/head of the commercial implant Ralgro®) to promote growth in suckling steer and heifer calves and of zeranol and progesterone-estradiol (Synovex-S®) as growth promotants in yearling steers at pasture. In each trial, approximately even numbers of animals were randomly alloted to a control (nonimplant) or an implanted group. Zeranol and progesterone-estradiol groups were implanted once at initial weighing. Animals were re-weighed when the trials were terminated at various times in the fall. Steer calves implanted with zeranol gained 4.2 and 5.0% more (P < 0.01) than controls for 1980 (0.98 vs. 0.94 kg/day) and 1981 (1.06 vs. 1.01 kg/day) trials, respectively. Zeranol-implanted heifer calves gained 3.5% more (P < 0.05) in 1980 trials (0.88 vs. 0.85 kg/day) and 7.4% more (P < 0.01) in 1981 trials (1.01 vs. 0.94 kg/day) than nonimplanted heifer calves. In trials where steer and heifer calves were pastured together, steers gained 3.4 and 5.0% more (P < 0.01) than heifer calves in 1980 and 1981, respectively. The trial × sex and sex × implant interactions were not significant. Both progesterone-estradiol- and zeranol-implanted yearling steers grew faster (P < 0.01) than control steers by 21.3 and 18.7% (0.91, 0.89 and 0.75 kg/day, respectively) over all 1980 trials, and by 13.0 and 11.7% (0.87, 0.86 and 0.77 kg/day, respectively) over all 1981 trials. Gains in yearling steers implanted with progesterone-estradiol were not different (P > 0.05) than gains in those implanted with zeranol. Key words: Beef cattle, zeranol, progesterone-estradiol, pasture
EFFECT OF GROWTH RATE ON THE INCIDENCE OF OSTEOCHONDROSIS IN GROWING SWINE
Authors: NAKANO T. , AHERNE F. X. , BRENNAN J. J. , THOMPSON J. R.
Published: March 2010

Eighty-eight, 4-wk-old Yorkshire × Landrace pigs (44 barrows and 44 gilts) averaging 8.0 kg were used to study the effect of growth rate on the incidence of osteochondrosis and some characteristics of hind limb bones. Forty-eight pigs (Group I) were fed control diets through the starter to finisher phases, while for the remaining 40 pigs (Group II), nutrient densities of starter and grower diets were increased to enhance growth rate. At an average liveweight of 94 kg, animals wer slaughtered, and humeri, ulnae, radii, and femurs were visually and histologically examined for soundness of cartilage and subchondral bone. Average daily gain was greater for Group II than for Group I during both the starter (0.58 vs. 0.43 kg, P < 0.01) and grower (0.84 vs. 0.74 kg, P < 0.05) phases, as was intended, and also greater (0.74 vs. 0.68 kg, P < 0.05) for Group II for the overal experimental period. The faster growth rate in Group II did not affect (P > 0.05) the incidence and severity of osteochondrosis in any joint (or bone) site examined. This was consistent with the nonsignificant (P > 0.05) correlations between growth rate and soundness scores of joint and bone, and the similarity (P > 0.05) of the soundness scores of pigs with fast growth rate (average daily gain, 0.82–1.00 kg), intermediate growth rate (0.74–0.76 kg), and slow growth rate (0.53–0.67 kg). Bone characteristics of the femur, tibia, and metatarsal bones were not influenced (P > 0.05) by growth rate. Key words: Growth rate, osteochondrosis, bone characteristics, swine
BLOOD HORMONE CHANGES ASSOCIATED WITH PUBERTY IN THE FEMALE PIG
Authors: PONZILIUS K.-H. , SANFORD L. M. , PHILLIPS G. D. , PALMER W. M.
Published: March 2010

Serum concentrations of reproductive hormones were determined in gilts around puberty. LH levels were low prior to pubertal estrus. FSH concentrations were high on day −5, decreased by day −1, then peaked simultaneously with the presumed preovulatory LH surge; a further increase was observed on day 3 of the first estrous cycle. Progesterone levels were consistently low prior to pubertal estrus and rose dramatically following ovulation. Peak levels of estrogen occurred between day −1 and day +1 of pubertal estrus. Key words: Blood hormone changes, puberty, female pig
THE EFFECT ON THE GROWTH OF BEEF HEIFERS OF AVOPARCIN IN A FREE-CHOICE MINERAL MIXTURE
Authors: VEIRA D. M. , IVAN M. , BUTLER G. , PROULX J.
Published: March 2010

Twenty crossbred beef heifers (7–9 mo) were fed grass silage ad libitum for 90 days, with a free-choice mineral mixture containing avoparcin (8 g/kg) while 20 other heifers were fed similarly but without avoparcin. Heifers offered the supplement gained 27% faster (P < 0.01) than controls, with no apparent effect on silage intake. Key words: Avoparcin, administration, cattle, growth
SELECTION LIMITS: HAVE THEY BEEN REACHED WITH THE DAIRY COW?
Authors: KENNEDY B. W.
Published: March 2010

Genetic theory suggests that at some point genetic progress for milk production might plateau either through exhaustion of genetic variability or through development of antagonistic genetic relationships between milk yield and components of fitness. Although there have been no long-term selection experiments with dairy cattle, empirical evidence from field data indicates that selection limits for increased milk production have not been reached nor will they be in the foreseeable future. The rate of genetic improvement in milk yield is accelerating. Rather than witnessing a decline in genetic variability, as genetic theory would indicate, we seem to be experiencing an increase in genetic variability as production levels increase with time which is likely due to improved management allowing for greater expression of genetic variability. There is some evidence of genetic antagonisms between milk yield and fitness traits, fertility and health measures in particular, and this could impose a limit to selection for increased milk production. The solution to this problem is probably through improved management of high producing cows, to reduce stress associated with high production. Key words: Dairy cattle, selection, genetic variation
ASSESSMENT AND CONSERVATION OF ANIMAL GENETIC RESOURCES IN CANADA
Authors: CRAWFORD R. D.
Published: March 2010

An assessment is made of the present Canadian situation regarding livestock and poultry genetic resources and of the need to take conservation measures as insurance against future needs. Loss of resources in poultry has been extreme, and loss is occurring rapidly now in dairy cattle. A complete inventory of poultry genetic resources kept by commercial breeders, hobbyists, and public agencies was prepared in 1979–1980; it is described in detail. There is an annual inventory of research stocks, both mammalian and avian. A brief survey has been made of rare and feral livestock. There is an urgent need for complete cataloguing of existing resources in the major livestock species — cattle, sheep and swine. Three conservation collections of poultry stocks are located in Canada. Conservation action is also needed for livestock, especially cattle and swine. Canadians have a duty to maintain their animal genetic resources. While commercial animal breeders and hobbyists have a role to play in conservation, the main responsibility should be assumed by public agencies. Key words: Animal genetic resources, conservation, assessment, livestock, poultry
FACTORS INFLUENCING LACTATION PERFORMANCE OF RANGE BEEF AND DAIRY-BEEF COWS
Authors: BUTSON SARAH , BERG R. T.
Published: March 2010

An investigation was carried out to study factors influencing milk yields and milk constituents among range cows. June and September measurements of milk yield and constituent percentages of butterfat (BF), protein (PT) and lactose (LT) were taken using 206 and 222 cows in 1976 and 1977, respectively. The cows, representing four beef and dairy-beef breed groups, were from the University of Alberta beef herd and ranged in age from 2 to 10 years. Regression of milk yield on calf age (CA) demonstrated a negative association over the lactation period measured, although regression coefficients were not statistically significant. Associations between all constituent yields with CA were negative. However, regression coefficients of June and September constituent percentage variables on CA indicated a more positive association as lactation progressed. Cow weight loss during gestation, cow weight at calving and ADG during lactation did not account for a significant proportion of the variation in either milk or constituent yields or constituent percentages over and above main effects. The association between cow ADG during lactation and all yields was negative although not statistically significant. Calf birth-weight was positively associated with all yields, and showed negative association with BF% and PT%. Calf average daily gain measured from birth to September was highly associated with yields of milk and constituents, declining from June to September. Its association with BF% and PT% was negative. Cow calving interval was introduced as a possible factor influencing milk yields of 3- and 4-yr-old and mature cows. Its association with lactation performance was however, not significant. Key words: Lactation, range cows
GENETIC EFFECTS AND RELATIONSHIPS AMONG CARCASS FAT CONTENT OF BROILER CHICKENS AND PLASMA TRIGLYCERIDE LEVELS AND LIVER TRAITS
Authors: PATTERSON D. L. , FRIARS G. W.
Published: March 2010

The phenotypic and genetic relationships among carcass traits were studied in four pure lines of 44-day-old female broiler chickens. Two diets with the same energy to protein ratio but different nutrient densities were used. Liver weight was the only trait significantly affected by diet, whereas no significant differences among lines were noted for blood plasma triglyceride levels, abdominal fat, percent carcass fat and moisture, and percent liver fat and moisture. A significant effect of line was observed for liveweight, carcass weight, fat-free carcass weight, and liver weight, with birds from the two sire lines being larger than those from the two dam lines. A pedigreed population of one of the pure lines gave moderate to low heritability estimates for the three liver traits. The phenotypic correlations of blood triglyceride levels with the other traits studied were very low. Phenotypic and genetic correlations showed that there might be some potential for using percent liver fat and moisture in predicting carcass fat. However, when prediction equations were developed on a within-line basis, percent liver moisture contributed significantly to the total variance of carcass fat in only one of the lines, and the contributions of other liver traits were not significant. Carcass moisture percent, carcass weight, and abdominal fat weight were of more value in predicting carcass fat than were the liver and blood traits measured. Key words: Broiler chickens, carcass fat, blood triglyceride, liver
EFFECTS OF FREQUENCY OF SEMEN COLLECTION AND INSEMINATION, AND NUMBER OF SPERMATOZOA INSEMINATED ON REPRODUCTIVE PERFORMANCE OF TURKEYS
Authors: ANSAH G. A. , BUCKLAND R. B. , CHAN C. W. , TOUCHBURN S. P.
Published: March 2010

Two experiments were conducted using broiler-type turkey breeders to determine the optimum frequency of semen collection, the frequency of insemination, and the minimum number of spermatozoa inseminated for efficient utilization of males and the maintenance of high levels of fertility. In each experiment, 60 males were housed in litter floor pens with 10 males per pen. In the first experiment semen was collected one, three or five times a week. At biweekly intervals, individually caged hens were inseminated with 0.02 mL of undiluted pooled semen from males under each semen collection frequency. On alternate weeks semen volume, spermatozoa concentration and percent live spermatozoa were determined. In the second experiment, semen was collected three times a week and individually caged hens were inseminated weekly or biweekly with diluted semen containing 50, 100 and 200 × 106 spermatozoa. Each experiment was carried out over a production cycle of 16 wk. Increased frequency of semen collection decreased (P < 0.05) semen volume, spermatozoa concentration and percent live spermatozoa. Fertility of semen was highest (P < 0.05) when collected three times a week during the production cycle and when inseminated weekly in doses containing 100 or 200 × 106 spermatozoa. Overall, fertility declined with the stage of the production cycle. Key words: Turkey, semen collection frequency, AI frequency, spermatozoa number, fertility
COMPARISON OF MALE STERILE CORN AND REGULAR CORN AS SILAGE FOR DAIRY COWS
Authors: BURGESS P. L. , NICHOLSON J. W. G.
Published: March 2010

The relative nutritive value of male sterile corn silage (23.7% dry matter) and regular corn silage (26.5% dry matter) was determined with lactating dairy cows during three consecutive crop years. The regular corn hybrid had 25% of the kernels removed by black birds prior to harvesting. Grain was fed according to milk production (1 kg/2.75 kg milk) and silage was offered ad libitum as the only forage. Dry matter, soluble carbohydrate and insoluble nitrogen percentages were lower while crude protein and acid detergent fiber levels were higher in the male sterile corn silage. Apparent digestibilities of dry matter, nitrogen and energy determined with sheep were not different between silages. Silage dry matter intake and total dry matter intake were higher (P < 0.05) for cows fed regular corn silage in only one of the three trials. Actual milk, 4% fat-corrected milk yields and milk fat and protein percentages were not affected by silage treatment. Key words: Male sterile corn, silage, dairy cows
EFFECT OF NITROGEN FERTILIZATION AND PLANT POPULATION ON THE VALUE OF CORN SILAGE FED TO BEEF STEERS
Authors: FLIPOT PAUL M. , MASON WESLEY , GENEST JEAN
Published: March 2010

Corn was grown at 86 000 plants/ha and at 129 000 plants/ha and fertilized with nitrogen at rates of 150 and 200 kg/ha in order to determine the effect of population and N-fertilization on field production, silage preservation and animal performance. Silages from the four field treatments were offered ad libitum to Hereford steers during 112 days. Within each of the corn treatments, half of the animals were supplemented with 450 g of soybean meal (48% protein). Under field conditions characteristic of this trial, the higher plant populations and higher nitrogen levels failed to increase corn silage yields and resulted in lower ear production, later maturing plants and a higher plant moisture content at harvest. The trends were most noticeable in the high plant population treatments. The quality of the silage was not affected by the different treatments. No significant differences for total N, soluble N, NH3-N, lactic acid and acetic acid were noted among silages. Animal intake was increased with silages produced on high N-fertilization at 86 000 and 129 000 plants/ha. No significant differences in animal gain or feed efficiency were observed due to field treatments. The addition of soybean meal to the silages diluted the influence of field treatment on animal intake. However, within field treatments the supplement significantly improved dry matter intake, gain and feed efficiency. This study showed no advantage in increasing corn population over 86 000 plants/ha or N fertilization above 150 kg/ha. Key words: Corn silage, plant population, N-fertilization, steers