bluuebunny/crossref_metadata_2025 huggingface dataset:
LINE-OF-MALE EFFECTS ON LIFETIME PERFORMANCE IN MICE
Authors: NAGAI J. , McALLISTER A. J. , MASAKI J.
Published: March 2010

Six straight-bred lines of mice were used both as straight-bred (STR) lines and to set up five crisscross (CC) lines (classes) and five repeat hybrid male cross (RHMC) lines, (classes). Females in each line were pair-mated with either males of the same line (group I) or males from a synthetic line (group II). Pairs were maintained for up to 155 days after mating (lifetime). Data from six generations were analyzed to examine differences between group I and group II in lifetime performance for each line in each generation. Line-of-male effects for the above difference (group I–Group II) expressed as a percentage of the average of group I and group II means were, under CC, RHMC and STR, −11, +5 and −2 for number of parturitions during 155 days, −12, +3, and −7 for total number of young born alive, −12, + 2 and −8 for total weight of young born alive, −12, +3 and −8 for total number of young at weaning, −11, +2 and −8 for total weight of young at weaning and −8, +3 and −1 for actual days of reproductive life, respectively. Lifetime performance of females differed depending on males used for mating, and F1 males were superior to males from the synthetic line which excelled males from straight-bred lines. Key words: Male, lifetime performance, reproduction, mice
EFFECTS OF ANHYDROUS AMMONIA ON AMINO ACID PRESERVATION AND FEEDING VALUE OF HIGH-MOISTURE EAR CORN FOR GROWING STEERS
Authors: PHILLIP L. E. , GARINO H. J. , ALLI I. , BAKER B. E.
Published: March 2010

A study was conducted to ascertain the feeding value for beef cattle of high-moisture ear corn (HMEC) treated with anhydrous ammonia. The trial was conducted with 36 Hereford steers (mean weight 240 kg) fed treated or untreated HMEC in combination with corn silage (4:1, dry matter basis). High-moisture ear corn containing 63% dry matter (DM) was untreated (control) or treated with cold-flow anhydrous ammonia (1% of fresh weight) and ensiled in tower silos. The control diet was supplemented with isonitrogenus amounts of urea added at feeding time. Steers fed ammonia-treated or urea-supplemented HMEC showed a 46% higher growth rate than those fed the nitrogen-unsupplemented diet. The growth response to ammoniation was 7% higher (P < 0.05) than that to urea addition. Organic matter intake was 10% higher with ammonia addition than with urea supplementation (P < 0.05). Ensiling HMEC with added ammonia resulted in increased protein nitrogen (N) and a reduced level of total free-amino-acid-N. In addition to reduced proteolysis, ammonia treatment improved aerobic stability of HMEC. It is suggested that the response in feed intake to ammoniation of HMEC may be mediated through its effect on aerobic stability and through a possible improvement in protein status of growing steers. Key words: High-moisture ear corn, ammoniation, proteolysis, feed intake, steers
COMPARATIVE PERFORMANCE AND DIGESTIBILITY IN DAIRY CALVES WEANED AT THREE, FIVE, AND SEVEN WEEKS OF AGE
Authors: WINTER K. A.
Published: March 2010

Ayrshire and Holstein bull calves were weaned onto dry feed at 3, 5, and 7 wk of age. Growth rates from birth to 14 wk of age, and feed intake and feed efficiency from 9 to 14 wk were not affected by weaning age. Dry matter digestibility in the week after weaning was similar for the different weaning age treatments and for the several digestion periods up to 14 wk of age. Nitrogen (N) retention was lower in the 3-wk weaned group immediately after weaning but when compared at uniform ages of 8 and 14 wk N retention was the same in the three weaning age groups. Total volatile fatty acids (VFA) in rumen fluid and proportions of acetic, propionic, and butyric acids were not affected by weaning age in the week after weaning and showed little change in proportions of individual VFA up to 14 wk, when the diet composition was constant. It was concluded that early weaning, at 3 wk of age, had little or no effect on the calf except for a slight slowing in growth during the week after weaning. Dry feed consumption increased rapidly and a relatively stable rumen fermentation developed as quickly in the calves weaned at 3 wk as in those weaned at 5 and 7 wk. In the week after weaning, dry matter and energy were digested as effectively in the early-weaned calves as in those weaned at 5 and 7 wk. Key words: Calves, weaning, digestibility, VFA
FOOT AND LEG MEASUREMENTS, TOE LESIONS, SOUNDNESS SCORES AND FEEDLOT PERFORMANCE OF CROSSBRED BOARS AS INFLUENCED BY NUTRITION AND AGE
Authors: LEPINE A. J. , KORNEGAY E. T. , NOTTER D. R. , VEIT H. P. , KNIGHT J. W.
Published: March 2010

The effects of reduced energy intake (ad libitum and 75% of ad libitum) and elevated mineral-vitamin intake (100 and 150% of NAS-NRC daily recommendations) on foot and leg development, incidence and severity of toe lesions, structural soundness scores and feedlot performance were studied in crossbred boars from 35 to 330 days of age (295 days on test). Toe measurements increased over time with little effect of elevated mineral-vitamin levels. At an equal age, ad libitum-fed boars had larger foot measurements; however, weight-correction usually produced larger values for limit-fed boars relative to body weight at 85 and 190 days on test. Incidence and severity of pad and horn lesions were generally not affected by the dietary treatments, but incidence of lesions was generally greatest for the hind outside toe. Limit-fed boars had higher (P < 0.05) soundness scores compared with ad libitum-fed boars, while dietary mineral-vitamin level had no effect. Daily gain of limit-fed boars was 76% that of ad libitum-fed boars with no overall affect on feed per gain ratio. Feedlot performance was similar between mineral-vitamin levels. The findings of this study indicate that elevating mineral and vitamin intake above that recommended by the NAS-NRC (1979) had no effect on toe, foot and leg development or the resulting structural soundness. Restricting feed intake produced boars with slightly larger toes which appeared more structurally sound when examined at an equal weight. Toe lesion scores, however, were similar between energy levels and there appeared to be no relationship between toe lesion scores and structural soundness scores. Key words: Boars, energy intake, minerals, vitamins, toe measurements, toe lesions, soundness
DRY MATTER, ETHER EXTRACT, ASH AND MINERAL COMPOSITION OF TOE HORN-WALL FROM CROSSBRED BOARS AS INFLUENCED BY NUTRITION AND AGE
Authors: LEPINE A. J. , KORNEGAY E. T. , BARTLETT H. S. , NOTTER D. R.
Published: March 2010

The effects of dietary energy level (ad libitum and 75% of ad libitum) and mineral-vitamin intake (100 and 150% of NAS-NRC daily recommendations) on dry matter, ether extract, ash and mineral composition of hard horn-wall taken from front and rear and inside and outside toes were studied in crossbred boars necropsied at 15-day intervals from 85 to 295 days on test starting at 35 days of age. With the exception of Ca and P contents which were higher for restricted-fed boars, restricted energy level and elevated mineral-vitamin intake had little or no effect on horn-wall composition, when expressed on a weight-corrected basis. Horn-wall dry matter, ether extract and Zn content increased over time while ash, P, Mg, Cu, Mn and Fe content decreased with little change in Ca content. Front toes had a lower ether extract, Fe and Mn content than hind toes, and outside toes had a higher content of P, Mg and Mn and a lower content of Cu and Zn than outside toes. Toe size (area and volume) was directly correlated with dry matter, Ca, P, Mg and Zn content, but was inversely correlated with ash, Cu, Fe and Mn content of horn-wall. There appeared to be no relationship between toe size and ether extract content of horn-wall. Horn-wall composition changes occurred over time with only minor effects of nutrition treatments. Although composition of horn-wall varied due to location and size of toe, there appeared to be no relationship between horn-wall composition and toe lesion scores. Key words: Swine, nutrition, toe horn-wall composition, minerals
GROWTH AND CARCASS TRAITS OF CROSSBRED AND PURELINE DAIRY STEERS
Authors: LEE A. J. , DREVJANY L. A.
Published: March 2010

Growth, feed conversion and carcass traits of 30 Holstein (H) line, 24 crossbred (C) line and 20 Ayrshire-based (A) line steers were compared. Although H and C calves were heavier at birth than A calves, body weights and dimensions at later ages up to 50 wk were similar for the three lines. H steers were superior to A and C steers in feed conversion from 48 wk to slaughter at 450 kg and in ribeye area. C steers had thicker fat cover, lower dressing percent and better overall carcass grades than H or A steers. Carcasses of A steers were less well marbled than those of H or C steers. Key words: Dairy, steers, carcass, Holstein, Ayrshire, crossbreds
EFFECTS OF ZERANOL ON SKELETAL GROWTH OF CULL COWS AND HEIFERS
Authors: CHAUDHARY Z. I. , PRICE M. A. , BUTSON S. , MAKARECHIAN M.
Published: March 2010

Thirty-two cull cows aged from 1 to 13 yr were allocated to five age groups and fed individually for 82 days, then slaughtered. Half of the cows within each group were implanted with 36 mg of zeranol. Zeranol had no significant effect on average daily gain, feed efficiency or backfat thickness, but caused a decrease in radio-ulna mass (P = 0.10) and length (P = 0.03). Rate of bone growth at the distal end of the radio-ulna decreased with increasing age to 0 at 4–5 yr. Key words: Cattle, bone growth, zeranol, cull cows, feedlot performance, carcass traits
PORK CARCASS GRADING: THE MAGNITUDE OF BREED AND SEX BIASES IN THE PREDICTION OF MEAT YIELD FROM A SINGLE FAT MEASUREMENT
Authors: RAE W. , JONES S. D. M. , KENNEDY B. W.
Published: March 2010

The magnitude of breed and sex biases in the prediction of meat yield using a single fat measurement was investigated under commercial conditions. Warm carcasses (n = 174) originating from four purebreeds (Yorkshire, 24 boars, 17 gilts; Landrace, 22 boars, 27 gilts; Hampshire, 24 boars, 15 gilts; Duroc, 21 boars, 24 gilts) weighing close to 80 kg were assessed for fat thickness at the maximum loin with a ruler (current Canadian carcass grading measurement) and at the last rib 70 mm from the midline with a Hennessey Grading Probe. All carcasses were evaluated for retail and lean yield 24 h post-slaughter. At the same carcass weight (78.7 kg), significant differences in both retail and lean yield were found (Hampshire > Landrace; boars > gilts), which largely reflected breed and sex differences in fattening. At the same loin fat thickness (25 mm) breed bias in retail yield amounted to 23 g/kg carcass, while sex bias amounted to only 2 g/kg carcass. At the same last rib, fat thickness breed bias in retail yield was reduced to 12 g/kg carcass, while sex bias increased to 4 g/kg carcass. The effect of changing sites of fat measurement from the loin to the last rib in this study resulted in a substantial reduction in breed bias (1.81 kg to 0.98 kg of retail yield), but to increased sex bias (0.15 kg to 0.28 kg of retail yield). Similar trends were found when lean yield was used as the base instead of retail yield. Prediction equations for retail and lean yield were found to be more precise using last rib fat thickness than those using the maximum loin fat measurement. It was concluded that breed bias would be reduced if last rib fat thickness was used to predict the meat content of pork carcasses. Key words: Boar, breed, gilt, pork grading, pork carcass, meat yield
SOLUBLE NUTRIENTS IN PROTEIN SUPPLEMENTS AND IN SITU DISAPPEARANCE
Authors: BARRIO J. R. , OWENS F. N. , GOETSCH A. L.
Published: March 2010

The effect of removal of soluble nutrients from soybean meal (SBM) and meat meal (MM) on in situ disappearance of dry matter (DMD) and nitrogen (ND) was measured. All feeds were rinsed with pH 6 buffer (R) without or with subsequent extraction with buffer at pH 5 (5) or pH 7 (7). Feeds were incubated in the rumen of heifers fed diets containing 20 or 80% concentrate (20%C and 80%C, respectively). Ruminal pH was higher (P < 0.05) in heifers fed the 20%C diet than in animals receiving the 80%C ration, while ruminal ammonia concentration tended to be greater with the 80%C diet. In situ DMD and ND were linearly related to incubation time (P < 0.01) with little indication of a quadratic effect of time. In situ ND of feeds extracted at pH 7 was greater (P < 0.05) than ND of feeds extracted at pH 5, but no interaction of diet and extraction pH or feed and extraction pH was apparent. Hence, altered protein solubility due to varied ruminal pH would not appear to be responsible for differences in ND with the different diets. In situ DMD and ND of both feedstuffs were greater (P < 0.01) with the 20%C than the 80%C diet. Hence, differences in microbial types or activities rather than chemical characteristics of the substrate are probably responsible for greater proetein loss with the lower concentrate diet. Key words: In situ, dry matter disappearance, nitrogen disappearance, soybean meal, meat meal
STUDIES ON THE USE OF HULLESS BARLEY IN CHICK DIETS: DELETERIOUS EFFECTS AND METHODS OF ALLEVIATION
Authors: CLASSEN H. L. , CAMPBELL G. L. , ROSSNAGEL B. G. , BHATTY R. , REICHERT R. D.
Published: March 2010

The true metabolizable energy value of hulless barley was found to be significantly higher than for hulled barley and similar to that of wheat for adult roosters. Substitution of hulless barley for wheat in broiler chick diets resulted in a significant linear depression of 3-wk weight, tibia ash, fat absorption and starch absorption. Addition of cellulase, antibiotic or irradiation of the grain increased the growth rate of the chicks receiving the hulless barley. All the treatments significantly increased fat absorption, but starch absorption was increased significantly only by enzyme addition. Tibia ash was increased significantly by addition of antibiotic. Autoclaving the hulless barley significantly reduced 3-wk weight and increased feed:gain ratio for the birds. Neither row type (two-rowed or six-rowed varieties) nor kernel hardness of the barley influenced chick growth on the hulless barley diets. Gamma irradiation or cellulase addition reduced the viscosity of the β-glucan solution indicating that these treatments may have increased the nutritional value of the hulless barley by depolymerization of the β-glucan. Key words: Barley (hulless), (β-glucan, gamma irradiation, enzyme supplementation, chicks
EFFECTS OF A WIDE RANGE OF DIETARY SALT LEVELS ON THE PERFORMANCE OF BROILER CHICKENS
Authors: PROUDFOOT F. G. , HULAN H. W. , NASH D. M.
Published: March 2010

Five dietary levels of sodium chloride (0.2, 0.4, 0.6, 1.0 and 1.8%) were used. Commercial broiler chickens tolerated 0.4–1.0% of dietary sodium chloride without adverse effects on performance. Key words: Broilers, salt, diets, sodium chloride
EFFECTS OF WARM VERSUS COLD MILK REPLACERS AND OF FREE-CHOICE HAY POSTWEANING ON PERFORMANCE OF ARTIFICIALLY REARED LAMBS
Authors: HEANEY D. P. , SHRESTHA J. N. B.
Published: March 2010

In two artificial rearing experiments lambs were fed, ad libitum, either cold (4.4–7 °C) or warm (27–31 °C) milk replacer with 0.10% formalin (37%, wt/wt, formaldehyde) added to the reconstituted milk replacer. From weaning at 21 days of age to 91 days of age all lambs were fed the same high-concentrate diet (corn grain, soybean meal, 8% ground hay plus minerals and vitamins; approx. 17% crude protein, as-fed). In the second experiment half the lambs from each milk replacer treatment were fed alfalfa hay free-choice postweaning in addition to the high-concentrate diet. Equal survival rates and absence of abomasal bloat on both milk replacer treatments showed that the addition of 0.10% formalin allows warm milk replacer to be safely fed ad libitum to lambs. Both intakes and gains were higher for lambs fed warm milk replacer than for cold. In the first experiment apparent compensatory postweaning growth nullified the weight advantage at weaning for lambs fed warm milk replacer, whereas in the second experiment the weight advantage at weaning was not overcome by the apparent compensatory growth. Feeding hay free-choice postweaning (amounted to 12.5% of the overall diet), in addition to the high-concentrate diet, improved lamb gains and slightly increased feed dry matter required per kilogram of gain, as would be expected as a result of the lower energy content of the overall diet. The results indicate that the addition of 0.10% formalin allows warm milk replacer to be safely fed ad libitum to lambs; that performance, including postweaning carryover effects will be equal to, or greater than that achieved with cold milk replacer; and that free-choice hay in addition to a high-concentrate diet postweaning has a beneficial effect on lamb performance. Key words: Lambs, artificial rearing, warm vs. cold milk replacer
UTILIZATION OF GRASS SILAGE BY CATTLE: EFFECT OF BARLEY AND FISHMEAL SUPPLEMENTS
Authors: VEIRA D. M. , IVAN M. , BUTLER G. , PROULX J. G.
Published: March 2010

Following weaning at 6–7 mo of age, 36 beef steers were used to determine production responses when grass silage was supplemented with barley or fishmeal. The silage was made from direct-cut, formic- acid-treated grass harvested from a mixed sward and had a high nitrogen content but poor fermentation characteristics. The silage was fed ad libitum for 98 days either alone or supplemented with 500 g fishmeal or 500 g barley per day. Both fishmeal and barley increased total dry matter intake (P < 0.01) by an amount equivalent to the quantity of supplement offered but had no effect on silage intake (P > 0.05). Steers fed the fishmeal grew substantially faster than either the barley (0.53 kg/day) or unsupplemented (0.54 kg/day) groups (P < 0.01). Fishmeal supplementation resulted in a large reduction (35%) in the amount of feed required per kilogram of gain. Key words: Cattle, grass silage, fishmeal, growth
CANOLA MEAL FOR LAYING HENS
Authors: SUMMERS JOHN D. , HUNT E. C. , LEESON S.
Published: March 2010

Laying hens were fed a corn, barley, soybean meal control diet and similar diets in which 10% of canola meal replaced an equal amount of soybean meal protein. One of the canola diets was kept equal in energy to the control diet by the addition of extra dietary fat, while the energy content was allowed to fall for an alternate treatment. While there were slight differences in performance, the main effect noted was a reduction in egg size for birds fed the canola diets. Fatty acid composition of egg yolk, liver and abdominal fat did not differ significantly between the three dietary treatments. In a second trial 10% canola meal was substituted on an isocaloric basis, into a corn-soybean meal basal diet. Over a 48-wk laying period, birds fed canola meal consumed less feed than those fed the soybean meal control which resulted in fewer eggs and also smaller egg size (P < 0.05). Key words: Laying hens, canola meal, egg composition
MINERAL PROFILE OF CANOLA AND SOYBEAN MEAL
Authors: SUMMERS J. D. , LEESON S.
Published: March 2010

Two experiments were conducted to compare the mineral profiles of canola and soybean meal. In a factorial arrangement, three supplemental levels of calcium (0.2, 0.4 and 0.6%) and three supplemental levels of available phosphorus (0.05, 0.1, and 0.15%) were fed with and without supplementation of 30 ppm of zinc. There was no response in weight gain, feed intake or percent bone ash, thus suggesting that zinc availability is unlikely to be a problem influencing the performance of poultry fed either of the protein supplements. Supplementation of both canola and soybean meal with either chloride, manganese, magnesium, iron or copper failed to demonstrate any meaningful responses which could be considered of interest in practical type diets in which the two protein supplements may substitute for one another. It is thus considered that none of the minerals investigated should be any more of a problem in practical type broiler diets in which canola meal is substituted for a portion of the soybean protein. Key words: Broiler chicken, canola meal, mineral profiles, mineral profile of soya and canola meals
INFLUENCE OF GLUCOSINOLATES AND FREE OXAZOLIDINETHIONE IN A LAYING DIET CONTAINING A CONSTANT AMOUNT OF SINAPINE ON THE THYROID SIZE AND HEPATIC TRIMETHYLAMINE OXIDASE ACTIVITY OF BROWN-EGG LAYERS
Authors: GOH Y. K. , ROBBLEE A. R. , CLANDININ D. R.
Published: March 2010

The effects of varying amounts of glucosinolate and free oxazolidinethione (OZT) in laying diets containing a constant amount of sinapine on thyroid size, hepatic trimethylamine (TMA) oxidase activity, and TMA levels in plasma and egg contents were studied. The diets fed contained aqueous extracts of RSM produced from high, medium and low glucosinolate cultivars (Oro, Span and Tower) which were included in amounts that provided the same level of sinapine in each diet. Thyroid size, plasma TMA levels and liver TMA oxidase activity were determined and eggs from individual birds in each treatment were analyzed for TMA content. The presence of progoitrin and free OZT in a laying diet significantly increased (P < 0.05) thyroid size and severely depressed hepatic TMA oxidase activity of the birds as compared to those fed a control diet. The degree of thyroid enlargement was largest for birds fed the Oro extract and was least for birds fed the Tower extract. The decrease in hepatic TMA oxidase activity, however, was greatest for layers fed the Tower extract and least for those fed the Oro extract. The decrease in TMA oxidase activity led to elevated plasma TMA levels and increased TMA content of eggs of brown-egg layers. Key words: Rapeseed meal, glucosinolate, oxazolidinethione, thyroid size, TMA oxidase, brown-egg layers
AMINO ACID SUPPLEMENTATION OF AMMONIATED MUSTARD MEAL FOR USE IN SWINE FEEDS
Authors: KEITH M. O. , BELL J. M.
Published: March 2010

Ammoniated mustard meal (MM) was prepared in a pilot plant by expelling and hexane-extracting brown mustard seed (Brassica juncea (L.) Coss.) and applying steam, ammonia and water in the desolventizer. Barley-wheat (2:1)-based diets containing MM (16.8%) or MM + lysine (0.20%) or MM + lysine + isoleucine (0.1%) were compared to similar diets containing soybean meal (15.3%) or canola meal (21.6%). Each diet was fed to eight crossbred barows between 24 and 52 kg liveweight. Chemical scores indicated that the unsupplemented MM diet was first- and second-limiting in lysine and isoleucine, respectively. Compared to the unsupplemented MM diet, supplemental lysine significantly improved the feed:gain ratio (2.80 vs. 2.51) while adding both lysine and isoleucine improved daily gain (574 vs. 684 g/day). Lysine and isoleucine supplementation resulted in significant increases in serum concentrations of these amino acids, confirming observations made regarding gains and feed:gain ratio. The isoleucine deficiency associated with MM-supplemented diets may be nutritionally important only in the early part of the grower phase. However, lysine supplementation appears to be necessary throughout the grower period. Key words: Mustard meal, ammoniation, feeding trial, serum amino acids, lysine, isoleucine
ANIMAL PRODUCTS, NUTRITION AND HEALTH: Introductory Remarks
Authors: BRISSON G. J.
Published: March 2010

not available
EFFECTS OF FEEDING COUMAPHOS TO DAIRY COWS AT VARIOUS STAGES OF LACTATION ON SUBCLINICAL PARASITE INFECTION AND MILK PRODUCTION
Authors: TAKAGI H. , BLOCK ELLIOT
Published: March 2010

Twenty-eight Holstein cows were allocated to 14 blocks of two cows each, balanced for previous lactation performance, stage of lactation and parity number. Cows within each block were randomly assigned to a treated or untreated (control) group. Treated cows received coumaphos on day 0 (December) according to manufacturer's recommendations and were re-treated when fecal worm egg counts increased in April, May and August. Control and treated animals were fed similar rations formulated according to production and had access to different but similar pastures during the pasture season (May to October). Milk was weighed daily and sampled weekly for fat and protein determination during the 50-wk trial. Treatment reduced fecal egg counts by 84.8% initially. Average egg count per 5 g feces was reduced to 15.1 in treated cows compared with 37.1 in controls. Tracer calves that grazed on pasture with control cows had an average of 6.3 times more gastrointestinal worms than calves grazing with treated cows. Milk production was not significantly different between groups for the 50 wk of the trial; however, compared with control cows, treated cows produced 2.07 kg d−1 more milk when on pasture and 3.9 kg d−1 more milk when housed indoors after the grazing season. Treatment reduced milk production during the initial housing period. Key words: Subclinical parasitism, dairy cattle (lactating), coumaphos, host-parasite relationships
LOW DIETARY ZINC INTAKE DURING PREGNANCY AND LACTATION OF GILTS. I. EFFECTS ON THE DAM
Authors: KALINOWSKI J. , CHAVEZ E. R.
Published: March 2010

Pairs of littermate gilts were fed semipurified diets (2 kg d−1) containing either 10 or 52 ppm Zinc (Zn) throughout pregnancy and the two first weeks of lactation (ad libitum). Low dietary Zn did not affect feed consumption or weight changes of gilts. Low-Zn gilts showed lower plasma Zn and alkaline phosphatase activity (APA) throughout gestation and lactation and lower iron (Fe) and copper (Cu) before the last third of pregnancy. Urinary Zn was very sensitive to low Zn intake. Plasma protein and ammonia (NH3) were not affected by treatment. One-half of the deficient gilts exhibited skin lesions. Low-Zn gilts showed prolonged and stressful parturition with high incidence of intrapartum mortality reflected in the number of stillbirths. Total liveweight of the litter at birth, 1 and 2 wk of age was lower in Zn-deficient gilts. Low Zn supply did not affect the protein content or the profiles of the serum proteins of colostrum or milk but did affect the mineral composition. Colostrum of low-Zn gilts showed higher Cu, Fe and manganese (Mn), whereas milk showed lower Zn and higher Cu. Results obtained emphasize the importance of Zn for a normal pregnancy, delivery and nursing performance of the gilt. Key words: Zinc, gilts, pregnancy, lactation, piglets
LOW DIETARY ZINC INTAKE DURING PREGNANCY AND LACTATION OF GILTS. II. EFFECTS ON THE OFFSPRING
Authors: KALINOWSKI J. , CHAVEZ E. R.
Published: March 2010

Zinc (Zn) depletion was induced in pregnant gilts by feeding a diet containing 10 mg kg−1 Zn from day 22 of pregnancy until day 14 of lactation. Offspring of depleted gilts were born with lowered body, liver and gut weights; augmented lung weight; reduced plasma Zn, copper (Cu), ammonia (NH3), and alkaline phosphatase activity (APA); reduced hematocrit; increased glucose and lactate. Delivery problems of the dam caused a high incidence of stillbirths due to intrapartum anoxia. During the first week of age, piglets from depleted gilts exhibited lower body weight and reduced viability; lower plasma Zn, APA and NH3. At 2 wk of age body and organ weights were not different from that of controls; overall mortality was higher; plasma Zn was lower but Cu was higher. Zn-depletion of the dam endangered the outcome of pregnancy and promoted physiological changes in the newborn that affected neonatal growth. Key words: Piglets, viability, hypoxia, zinc
GENETIC AND PHENOTYPIC PARAMETERS FOR DAILY GAIN AND BODY WEIGHTS IN DORSET LAMBS
Authors: SHRESTHA J. N. B. , VESELY J. A. , CHESNAIS J. P. , CUTHBERTSON D.
Published: March 2010

The paternal half-sib estimate of heritability computed from 14 316 Dorset lambs across Canada was 0.50 ± 0.04 for daily gain from 50 to 100 d of age, 0.31 ± 0.03 and 0.47 ± 0.04 for lamb weights at 50 and 100 d of age. Estimates of genetic and phenotypic correlations between daily gain from 50 to 100 d of age and 100-d lamb weight were 0.86 ± 0.02 and 0.76, respectively. Corresponding correlations among lamb weights at 50 and 100 d were 1.02 ± 0.02 and 0.73. Key words: Dorset, lamb weights, genetic and phenotypic parameters
CARCASS CHARACTERISTICS OF BISON (Bison bison) STEERS
Authors: HAWLEY A. W. L.
Published: March 2010

Six bison (Bison bison) steers, slaughtered at 2.5 yr of age after receiving a finishing ration for 78 days, averaged 444 kg total body weight with a dressing percentage of 60%. Approximately 46% of the carcass was in the hindquarter. The carcasses averaged 3.1 cm fat depth at the top of the ribeye and 1.1 cm at the bottom. Fat deposition was localized to the top of the shoulder and loin and around the kidneys. The yield of marketable meat averaged 77% of cold carcass weight. Key words: Bison, carcass characteristics
THE BREEDING SEASON AND OVULATION RATE OF DLS EWES AS DETERMINED BY LAPAROSCOPY
Authors: FAHMY MOHAMED H. , DUFOUR JACQUES J.
Published: March 2010

Ovaries of 19 DLS (1/2 Dorset 1/4 Leicester 1/4 Suffolk) ewes were examined by laparoscopy at 16- to 18-day intervals to determine the length of the breeding season. Nine ewes (47%) had corpora lutea (CL) and/or corpora albicantia (CA) between 22 Apr. and 26 May 1983. The average date of the first estrus accompanied by mounting was 28 Aug. ± 10 d in 1983 and 20 Sept. ± 15 d in 1984. The interval between first and last observed CL and first and last mounting averaged 251 ± 28, and 222 ± 32 d, respectively. The average dates in 1984 when mounting ceased and CL and CA were last observed were 11 Apr. ± 26 d, 26 Apr. ± 27 d and 9 May ± 30 d, respectively. The anestrous period averaged 133 ± 28 d. The average ovulation rate at the last two cycles of a season and the first two cycles of the following breeding season were 1.6 ± 0.53 and 1.7 ± 0.65 for the 1983 and 1.1 ± 0.31 and 1.4 ± 0.71 for the 1984 seasons, respectively. Key words: Breeding season, ovulation rate, laparoscopy, DLS sheep
INHIBITORY EFFECT OF MEADOW FOXTAIL (Alopecurus pratensis) ON THE GROWTH OF STEERS
Authors: RODE L. M.
Published: March 2010

Yearling steers grazing meadow foxtail gained 0.91 kg d−1 compared to 1.14 kg d−1 (P < 0.05) for steers grazing timothy over a 101-d grazing season. Steers were then offered timothy-alsike clover hay for 56 d. Steers that previously grazing meadow foxtail gained 0.54 kg d−1 compared with 0.64 kg d−1 (P = 0.06) for their counterparts from timothy pastures. Key words: Yearling steers, pasture, meadow foxtail, timothy, growth inhibition
GROWTH AND SURVIVAL OF RATS FED SWINE DIETS SUPPLEMENTED WITH VITAMIN K AND/OR WARFARIN
Authors: JONES R. W. , EASTER R. A.
Published: March 2010

A concern that the supplementation of swine diets with vitamin K may overcome the effects of warfarin-based rodenticides used in swine facilities was evaluated. Rats did not respond to additional vitamin K and all rats fed warfarin died within 5 days, indicating that vitamin K supplementation of swine diets should not impede rat control. Key words: Vitamin K, warfarin, swine, rats
COMPARATIVE PRODUCTIVITY OF COWS AFTER RECEIVING TWO EMBRYOS AT TRANSFER
Authors: REID J. P. , WILTON J. W. , WALTON J. S.
Published: March 2010

Embryos were transferred surgically to each uterine horn of 31 recipient cows. Fourteen (45%) became pregnant. Nine of the pregnant recipients calved twins for a rate of 64% twins per pregnancy. Embryos were obtained from nine donors by nonsurgical flushing, with the resulting single and twin calves offspring of six of these. Donors were crossbreds of varying percentage of Charolais, Chianina, Maine Anjou, Simmental and Holstein; service sires were Charolais, Limousin or Maine Anjou and the calves were therefore 2-, 3- or 4-way crosses. Recipients included a wide range of crosses of breeds, varying in milk yield and mature weight. In addition to the twins produced by transfer, an additional six sets of twins were born during the same period to cows bred by artificial insemination (AI). Single and twin calves produced by AI service were sired by bulls of breeds similar in mature weight to that of the dam. At calving, 79% of the twinning cows required assistance compared to 29% of the single bearing cows. The most common problem observed for cows bearing twins was presentation of both calves at the same time, although this problem was easily corrected in all cases. Calf mortality was low and not significantly different between twin- and single-bearing dams. Days to first ovulation were similar for twin and single nursing cows, 39 and 34 d postpartum, respectively. Transfer twin calves were 16.6 kg lighter at birth and gained weight at a significantly slower rate (249 g d−1) from birth to weaning than transfer calves born as single. Milk production of transfer twin-bearing dams as measured by average machine yield at 5, 12 and 20 wk of lactation was significantly greater (340 kg 200 d−1) than for dams bearing a single transfer calf. Total mass of weaned calf per cow was 151 kg greater for dams with transfer twins than those with transfer singles and 165 kg greater for AI dams with twins than AI dams with singles. Within the transfer twin group, milk yield of dam significantly influenced total weight of calf produced (0.02 kg kg−1 milk) while weight of dam did not. Key words: Embryo transfer, beef, twins, recipients, milk yield, reproductive performance
RESPONSE TO SELECTION FOR BODY WEIGHT OR FEED EFFICIENCY IN MICE TESTED ON CORN, RYE AND WHEAT DIETS
Authors: McKAY R. I. , PARKER R. J. , GUENTER W.
Published: March 2010

Mass selection for adjusted feed efficiency (AFE, g gain/g feed) and adjusted body weight (ABW, g) of male mice was practiced for seven generations on each of three diets: corn, rye and wheat. The three experimental diets, fed between 21 and 35 d, were isocaloric (approximately 16.5 MJ GE kg−1) and isonitrogenous (CP approximately 13%). A common commerical diet (PC) was fed at all other times. With each diet two control lines, randomly mated, were tested on either the experimental diets (DC) or a commercial diet (PC). Selection was based upon linear adjustment to a common initial weight (10 g) for either final weight (ABW) or feed efficiency (AFE) measured between 21 and 35 d of age. Response was determined as a deviation from the appropriate DC line. All animals were placed in specially designed individual cages during the test period. Half-sib estimates of heritability in the PC line were 0.13(± 0.11) for ABW and 0.19(± 0.10) for AFE. Half-sib estimates pooled across lines and diets were 0.16(± 0.07) for ABW and 0.28(± 0.07) for AFE. Realized heritabilities for ABW were 0.24(± 0.06), 0.06(± 0.07) and 0.14(± 0.06) for the corn, rye and wheat diets, respectively. Response to selection for AFE was poor with the highest heritability obtained on the wheat diet (h2 = 0.13 ± 0.02). Key words: Selection, mice, body weight, feed efficiency, diets
RALGRO® IMPLANTS FOR INTACT MALE CALVES
Authors: RICHARDS J. E. , MOWAT D. N. , WILTON J. W.
Published: March 2010

Forty-eight spring-born bulls (representing early-, medium- and late-maturing breed groups) and 30 fall-born bulls (representing medium- and late-maturing breed groups) were randomly assigned to either a control or treatment group within each breed group. Treated bull calves were initially implanted with Ralgro® at approximately 55 d of age and reimplanted every 84 d for a total of four implants. All bulls were weaned after 140 d on trial at an average age of 195 d, placed into a feedlot in pens of three or four within breed and treatment groups and gradually adjusted to a high grain ration. Bulls were slaughtered when they reached approximately 7 mm of backfat over the 12/13th ribs, determined ultrasonically. Weaning weights and daily gain to weaning were increased slightly, but not significantly, by implanting in both calving groups. Effects tended to be more pronounced with the earlier (medium) maturing breed groups. No effect of implanting on feedlot performance was observed in either the spring- or fall-born bulls. A reduction in the morbidity rate of the spring-born implanted bulls tended to occur during a period of disease outbreak shortly after weaning. Testicular weights were reduced (P < 0.05) with the use of implants in both calving groups. Scrotal circumference was decreased (P < 0.05) by implanting in the spring-born bulls only. For both of these traits, effects were also more pronounced in the early- and medium-maturing breed groups. Effects of implanting on carcass characteristics were slight. Key words: Ralgro®, bulls, live performance, carcass characteristics, testicular development
GROWTH, DIGESTIBILITY AND VOLUNTARY INTAKE BY YEARLING STEERS GRAZING TIMOTHY (Phleum pratense) OR MEADOW FOXTAIL (Alopecurus pratensis) PASTURES
Authors: RODE L. M. , PRINGLE W. L.
Published: March 2010

Two experiments were conducted to compare the performance of animals grazing meadow foxtail or timothy pastures. In the first experiment, yearling Hereford steers continuously grazed timothy or meadow foxtail pastures (two 2.0-ha pastures/treatment using a put-and-take grazing system for three consecutive years). Carrying capacity was 443 and 501 animal-days ha−1 for timothy and meadow foxtail, respectively (P<0.01). Average daily gain was 1.13 and 0.79 kg d−1 for steers grazing timothy and meadow foxtail, respectively (P < 0.01). Despite a lower carrying capacity, timothy pastures produced more 502 vs. 391 kg liveweight ha−1 yr−1 than meadow foxtail pastures (P < 0.01). In the second experiment, lignin and chromium mordanted fiber were used as dual markers to estimate digestibility and voluntary intake of grazed forage by four mature fistulated steers (two steers/treatment) over the grazing season. Digestibilities of dry matter (DM), crude protein (CP) and acid detergent fiber (ADF) were greater for timothy than for meadow foxtail (P <0.01) but no differences were observed for DM and digestible DM intake. Differences in forage quality, forage DM available for grazing or DM digestibility were not sufficient to explain the lower performance of steers grazing meadow foxtail compared to timothy. Key words: Pasture, forage quality, animal performance, timothy, meadow foxtail, beef cattle
GRAIN SCREENINGS AS A DIETARY COMPONENT FOR PIGS AND SHEEP. II. ANIMAL UTILIZATION
Authors: TAIT R. M. , BEAMES R. M. , LITSKY J.
Published: March 2010

The digestibility of four types of grain screenings, No. 1 screenings, rapeseed screenings, mixed feed oats and refuse screenings was measured with pigs, rats and sheep. For the pig diets, hammermilled screenings replaced 60% of a complete basal diet, with the exception of the rapeseed screenings, where replacement level was 10% (hammermilled) and 20% (whole). Digestibility values were determined by difference. In the rat diets screenings were incorporated to provide 1.5 g N 100 g−1 dry matter (DM) and the biological value (BV) of the protein was also measured. In the sheep diets, all screenings except rapeseed were provided as the sole dietary component, with the No. 1 feed screenings and the mixed feed oats pelleted without prior grinding and the other screenings ground before pelleting. For rapeseed screenings, incorporation in the sheep diets was at a level of 30%. For No. 1 screenings, apparent digestibility of organic matter (OMD) and nitrogen (ND) for pigs was 82.3 and 83.2%, respectively; BV for rats was 77.4%, while OMD and ND for sheep was 73.9 and 72.7%, respectively. For rapeseed screenings, OMD and ND for pigs for the hammermilled screenings were 46.1 and 50.7%, respectively, and for the whole screenings were 30.3 and 11.5%, respectively. Biological value (rats) was 80.0%, while for sheep OMD and ND it was 63.9 and 77.4%, respectively. For mixed feed oats, OMD and ND for pigs were 63.8 and 82.6%, respectively; BV (rats) was 61.1% and OMD and ND for sheep were 64.2 and 73.4%, respectively. For refuse screenings, OMD and ND for pigs were 63.8 and 65.4%, respectively; BV (rats) was 83.8%, while OMD and ND for sheep were 59.9 and 65.3%, respectively. Number 1 feed screenings are of a high nutritive value and are suitable as a grain for both pigs and sheep. Unprocessed rapeseed screenings are unpalatable for pigs with both dry matter and protein poorly utilized. With sheep, pelleted rapeseed screenings are readily accepted, and the nitrogen is well digested. If mixed feed oats are ground, protein is well digested by both species although dry matter digestibility is low. Refuse screenings appear to be suitable only for ruminant diets. Key words: Grain, wheat, barley, oats, rapeseed, screenings
PRODUCTIVITY OF THE COW-CALF UNIT IN RANGE CATTLE PROTECTED FROM HORN FLIES, Haematobia irritans (L.), BY PESTICIDAL EAR TAGS
Authors: HAUFE W. O.
Published: March 2010

Experiments conducted on a ranch in southern Alberta evaluated the productivity of the cow-calf unit in breeding herds in response to treatment with pesticidal (8% fenvalerate wt/wt) ear tags to control infestations of horn flies, Haematobia irritans (L.). Optimum economic productivity was found to depend on the effectiveness of tags in establishing fly-free grazing (FFG) conditions and maintaining them without interruption during the complete summer grazing period. This was achieved when animals were tagged before the first overwintering horn flies emerged in spring. Present formulations of pesticide in tags will support the required FFG conditions for 85–90 d. Management of herds for maximum gains throughout the summer in southern Alberta requires fly control that will maintain FFG conditions for at least 115 d. Rates of gain in weight of animals under FFG conditions on dry range conformed with the 16% improvement in efficiency of production projected from controlled experiments on irrigated pastures. Key words: Cattle, cow-calf unit, flies, Haematobia irritans, ear tags, fenvalerate
THE INFLUENCE OF TEMPERATURE AND GENOTYPE ON THE GROWTH RATE OF HATCHERY-REARED SALMONIDS
Authors: SADLER S. E. , FRIARS G. W. , IHSSEN P. E.
Published: March 2010

Growth rates of three salmonid species, brook trout (Salvelinus fontinalis), lake trout (S. namaycush), and rainbow trout (Salmo gairdneri) and one hybrid, splake (S. namaycush × S. fontinalis) were compared at 10 and 16 °C. Two strains of each species, and one of the splake hybrid were examined. At 10 °C the ranking of specific growth rate from highest to lowest for species was: rainbow trout, lake trout, splake, brook trout. At 16 °C the order was: brook trout, rainbow trout, splake, and lake trout. Brook trout, rainbow trout and splake had significantly higher specific growth rates at 16 °C but lake trout showed no difference at the two temperatures. Strain differences were significant in lake trout and rainbow trout, but not in brook trout. Rainbow trout showed a significant strain by temperature interaction. The ranking of feed conversion efficiencies from best to poorest was: lake trout, 10 °C; splake, 10 °C; brook trout, 16 °C; splake, 16 °C; rainbow trout, 16 °C; rainbow trout, 10 °C; lake trout, 16 °C; brook trout, 10 °C. Key words: Temperature, genetics, growth, salmonids, aquaculture
RELATIONSHIP OF SOMATIC CELL CONCENTRATION WITH MILK YIELD IN DAIRY COWS
Authors: BATRA T. R.
Published: March 2010

The relationship between somatic cell count (SCC) and milk yield was studied using the data of 2181 composite milk samples collected once every 2 mo during 1982–1983 from 665 cows of the Ottawa herd of the National Cooperative Dairy Cattle Breeding Project. SCC was treated either as a continuous (log SCC) or a classification variable. The data, when SCC was treated as a continuous variable, were analyzed separately for the first and later lactations. The model contained the effects of genetic group, stage of lactation, season of calving, and log SCC as a covariable. As a classification variable SCC was partitioned into 10 classes and the data for the first and later lactation cows were combined. The model included the effects of genetic group, parity, stage of lactation, season of calving, and SCC classification. Lactation SCC was calculated as the average of actual individual SCC tests during the lactation. The model for the lactation milk yield included the effects of genetic group and parity, with log SCC and days in milk as covaribles within parity groups. The effects of genetic group, parity, stage of lactation, season of calving and SCC were significant (P < 0.01) for daily milk yield. Average daily milk yield loss was 0.5 kg and 0.7 kg for the first and later lactation cows, respectively, when the SCC increased from 200 × 103 to 400 × 103 cell mL−1. Lactation milk yield loss per unit increase in average log SCC was 74 kg in the first lactation and 88 kg for later lactations. These relationships were linear, suggesting that loss of milk yield per unit increase in SCC was greatest when SCC was low. Key words: Somatic cell count, milk yield
THE EFFECTS OF WEANING SCHEDULE, DURATION OF MILK FEEDING AND FISHMEAL ON CALF PERFORMANCE
Authors: BUSH R. S. , NICHOLSON J. W. G.
Published: March 2010

Two experiments were conducted to measure the effects of weaning procedure and duration of milk feeding on calf performance and overall milk consumption. In exp. 1, compared with calves weaned when consuming 500 g d−1 of starter (control), those weaned when intake reached 1000 gd−1 (delayed) consumed 2.5 times as much milk and those fed gradually diminishing milk levels until weaned at 1500 g d−1 of starter intake (gradual) consumed about 1.5 times as much milk. Both the control and delayed groups experienced a growth setback of up to 8 d at weaning. There was no change in growth rate for the gradual weaning group. In exp. 2, the calves were gradually weaned over 7 d commencing at 28 d of age and were fed either supplemental milk, wet fishmeal, dry fishmeal or no protein supplement (control) for an additional 140 d. Calves fed milk grew fastest and had the best feed:gain ratio (P < 0.01). Those fed fishmeal grew faster than the controls and had better feed:gain ratios (P < 0.01). There was no difference between the wet and dry fishmeal suggesting that any increased rumen by-pass through the esophageal groove reflex did not result in improved animal gain. The potential value to the producer of feeding over quota milk to calves marketed at 168 d was calculated to be $15.22 hL−1 on the basis of dry feed replaced and increased weight gain by the milk-fed calves. Key words: Calves, milk, weaning, by-pass protein, fishmeal
PARTITIONING METABOLIZABLE ENERGY UTILIZATION IN RUMINANTS TO INCLUDE A FACTOR FOR ASSIMILATION OF FOOD INTAKE AND ITS APPLICATION FOR EVALUATING ENERGY REQUIREMENTS OF GROWING-FATTENING CATTLE
Authors: GIRARD V.
Published: March 2010

A mathematical analysis of heat production by growing ruminants was used to assess the physiological importance of assimilation and digestion of dry matter intake. Energy retention (ER) was calculated according to National Academy of Sciences-National Research Council (NAS-NRC) (1984) for 300- and 600-kg cattle fed hay or corn silage with approximately 0, 25, 50 and 75% oat or corn grain. Protein synthesis was calculated for each ER using NAS-NRC (1984) standards for medium- and large-frame bulls, steers and heifers. Fat retention was then estimated by removing the caloric value of protein from ER and dividing the result by the caloric value of fat. Heat production (Y, MJ), obtained as the difference between metabolizable energy (ME) intake and energy retention, was related to the animal's metabolic weight (X1, kg), to the protein (X2, kg) and fat (X3, kg deposited and to the dry matter intake (X4, kg):[Formula: see text]This equation explained 99.9% of the variation of individual heat productions predicted by the California net energy system (NAS-NRC 1984). Heat production per kilogram dry matter intake (3.85 MJ) ranged from 38% at maintenance to 48% above maintenance of the total heat produced, which is similar to values reported in the literature from physiological studies. Metabolizable energy efficiency for fasting, gain of protein and gain of fat was respectively 102, 63 and 64%, whatever feed-stuffs were used. The proposed energy system can be summarized and used as follows: ME requirement = ME for fasting + ME for gain of fat + ME for gain of protein + ME for dry matter intake. In this form, ordinary ME values for feedstuffs are used. Key words: Ruminant, growth, protein fat efficiency, system, intake energy