bluuebunny/crossref_metadata_2025 huggingface dataset:
THE NUTRITIVE VALUE OF WHEAT SCREENINGS AS A FEED INGREDIENT FOR ADULT LEGHORN HENS
Authors: PROUDFOOT F. G. , HULAN H. W.
Published: March 2010

Nine hundred and twenty Leghorn hens were used in two experiments designed to evaluate the effects of feeding adult diets containing ground wheat screenings at 0, 15, 30, 45 and 60% of diets which were calculated to be isoenergic and isonitrogeneous. Results from both experiments reveal that there were no significant (P > 0.05) dietary effects for mortality, egg production, egg specific gravity, egg Haugh units or body weights. The higher dietary levels of wheat screenings were associated with a significant (P < 0.05) linear depression in feed efficiency. In exp. 2 hens fed the diet with 60% wheat screenings were significantly delayed in reaching a 50% rate of egg production and laid eggs which, at 182 d of age, weighed significantly less than eggs laid by hens fed diets with lower levels of wheat screenings; but as these results did not occur in exp. 1 these effects on sexual maturity and egg weight are inconclusive. It can be stated that layer diets may contain up to 45% wheat screenings without the expectation of a depression in biological performance. Key words: Wheat screenings, diets, Leghorn hens
RELATIONSHIP BETWEEN FECAL EGG COUNTS AND TOTAL WORM COUNTS IN SUBCLINICALLY PARASITIZED CALVES AND EXAMINATION OF POSSIBLE VARIATIONS IN FECAL WORM EGG EXCRETION BY COWS
Authors: BLOCK ELLIOT , TAKAGI HIROSHI
Published: March 2010

The relationship between fecal worm egg count in fecal grab samples and total gastrointestinal worms was examined in 25 young steers. Also examined was the possible diurnal variation in worm eggs shed in feces using 10 lactating cows housed in stalls equipped for total fecal collection. In the steers, a relationship was observed (r = 0.64, P < 0.01) between fecal grab sample egg count and total gastrointestinal female worm count transformed by common logarithm. In the lactating cows, there was no evidence of diurnal variation in fecal grab sample worm egg counts. Most of the variation in the total number of worm eggs shed in feces in a 24-h period was accounted for in the fecal grab samples. The fecal egg count was considered to provide information with sufficient precision in making decisions on programs for the diagnosis and treatment of gastrointestinal parasitism. Key words: Subclinical parasitism, dairy steers, lactating cows, fecal egg count
EXTENSION FACTORS FOR PREDICTING 305-DAY PROTEIN YIELD IN DAIRY COWS
Authors: BATRA T. R.
Published: March 2010

A total of 53 590 complete lactation records of four breeds (Ayrshire, Guernsey, Holstein, Jersey) were grouped into two ages at freshening (less than 36 mo and greater than or equal to 36 mo) and four seasons of calving (March to May, June to August, September to November, and December to February). Separate sets of extension factors were estimated for each breed, age group and season of calving using nonlinear model method. A new set of data was used to test these factors. Key words: Extension factors, protein, dairy cattle
EFFECT OF MEASUREMENT METHOD, BREED, AND TECHNICIAN ON SCROTAL CIRCUMFERENCE MEASUREMENTS
Authors: COULTER G. H. , KOZUB G. C. , MAPLETOFT R. J.
Published: March 2010

Three methods were used by three technicians to measure the scrotal circumference (SC) of three breeds of yearling beef bulls. Variance of an individual SC measurement was affected most by bull. Technician and measurement error components were much smaller. The Society for Theriogenology method of obtaining SC measurements was recommended for use in Canada. Key words: Scrotal circumference, methods, variance components, recommendations
THE CHEMICAL COMPOSITION AND NUTRITIONAL VALUE FOR CHICKENS OF MEAL FROM RECENT CULTIVARS OF CANOLA
Authors: BLAIR R. , MISIR R. , BELL J. M. , CLANDININ D. R.
Published: March 2010

Meals of Triazine-tolerant and Westar canola were found to be similar in chemical composition and nutrient content to commercial canola meal. Male broiler chickens grew at a similar rate from 2 to 4 wk when fed diets based on 20% commercial canola meal, meal from the cultivars, or soybean meal. Key words: Canola, cultivars, composition, nutrition, feedstuffs, chickens
ECONOMIC, MARKETING AND POLICY CONSTRAINTS AFFECTING ANIMAL PRODUCTION IN CANADA
Authors: ROSAASEN K. A. , LOKKEN J. S.
Published: March 2010

The current economic, marketing and policy constraints facing the animal production industry in Canada are examined. An historical review indicates the consequences (sometimes unintended) of economic or policy changes in the past in the areas of land settlement, marketing and grading. Natural factors constraining production such as gestation periods and climate and human factors such as consumption potential both physically and socially are considered. Government policy is identified as a key determinant in the animal production industry and an alternative explanation of the activity of government in the economy is outlined. The effect of economic and policy variables including interest rates, feed prices, economies of scale, productivity gains, trade policy, tax policy, grain and livestock marketing and stabilization on animal production are described. Throughout, the importance of government policy in determining the development of the animal production industry is emphasized. The major areas of tax policy and grain support programs in Western Canada are key determinants of regional livestock production patterns. The future of these policies is uncertain and this uncertainty is a major constraint to animal production in Canada. Uncertainty has always been a major constraint on animal production. Producers have developed mechanisms to deal with market variation, biological factors such as disease, fluctuating interest rates and the whims of the environment. However, a major source of uncertainty has not been addressed: — government policy. In part, this uncertainty is due to the on-again, off-again policies governments have followed. But history indicates it is foolish to believe that all important variables are within the control of government. Policy evolves through a political process that often reflects the interests of special interest groups rather than the long-term interests of producers or consumers. Change occurs slowly, impeded by resistance from those in favored positions within the current system. Policy uncertainty remains as a key variable to be addressed by the livestock industry in Canada. Key words: Animal production, economic constraints, policy constraints, policy uncertainty
BLOOD COMPOSITION OF DIFFERENT BEEF BREED TYPES
Authors: TONG A. K. W. , DOORNENBAL H. , NEWMAN J. A.
Published: March 2010

Two studies were conducted to examine the blood composition of cattle of different breed types. The first study involved 357 crossbred cows of Hereford × Angus, Charolais × British breed, Simmental × British breed and Limousin × British breed crosses, ranging in age from 12 to 14 yr. Sixteen blood characteristics were measured from the June and September blood samples. The second study used 23 Shorthorn cow-calf pairs from a line selected for yearling weight and 25 cow-calf pairs from a corresponding unselected control line of Shorthorns. These cow-calf pairs were bled 11 times, starting at calving and then at 28-d intervals thereafter, with 11 blood characteristics measured. The crosbred cows differed significantly in hemoglobin, packed cell volume, triiodothyronine, thyroxine, urea nitrogen, glucose, inorganic phosphorus, alkaline phosphatase, creatinine, uric acid and serum total protein. Increased yearling weight resulting from selection was associated with higher blood creatinine levels at maturity (P < 0.05) and during pre- and post-weaning growth (P < 0.01). These results support the view that blood composition exhibits genetic variation. Key words: Beef cattle, blood composition, breed type, selection for yearling weight
RELATIONSHIP BETWEEN LAMB BIRTH WEIGHTS AND FETAL PLASMA GROWTH HORMONE AND INSULIN CONCENTRATIONS
Authors: MEARS G. J.
Published: March 2010

Plasma concentrations of growth hormone (GH) and insulin were monitored in 11 chronically cannulated ovine fetuses and their mothers during the last month of gestation to obtain information on the role that these hormones have in determining fetal growth rate. Maternal plasma GH and insulin concentrations were independent of stage of gestation and lamb birth weights. Fetal plasma insulin concentrations were episodic in nature, independent of stage of gestation, and tended to be higher in fetuses that were heavier at birth. Fetal plasma GH concentrations were only slightly episodic in nature, were tenfold higher than maternal levels at 116–124 d gestation and increased by approximately another 25% prior to parturition. Fetal plasma GH concentrations were negtively correlated with lamb birth weights. In twin preparations, fetal plasma GH concentrations were significantly lower in the twin that was heaviest at birth. The lower GH concentrations found in faster growing fetuses are suggestive of a more rapid metabolic clearance of GH by the tissues of these animals. The results indicate that circulating fetal GH and, possibly, insulin are involved in determining the rate of ovine-fetal growth. Key words: Ovine birth weights, fetal GH, fetal insulin, fetal growth
OXALATE CONCENTRATION IN FEEDS AND ITS METABOLISM BY PONIES
Authors: CYMBALUK N. F. , MILLAR J. D. , CHRISTENSEN D. A.
Published: March 2010

Total oxalate and calcium determinations were made in 200 feed samples. Legume hays contained more oxalate than legume-grass, grass (including brome and timothy), native grass and cereal hays (P < 0.05). Grass, native and cereal hays contained low calcium and low to moderate oxalate concentrations. Based on molar ratios and the assumption of preferential binding of calcium by oxalate, it was estimated that about 25% of calcium in legume and legume-grass hays could be bound by oxalate. Similarly, oxalate might bind 38–44% of the calcium contained in native grass and cereal hays and would exacerbate the low calcium content of these hays. Only one hay, a kochia, had oxalate concentrations (3.2%) known to cause acute toxicity in livestock. Oxalate concentration was positively correlated to calcium concentration (r = 0.69). Chopped alfalfa, oat, brome, and slough hay and pelleted alfalfa, oat and barley hays were fed to ponies in two separate Latin square experiments. Apparent oxalate digestibilities were determined to be 48–88%. Cereal hays had the highest apparent oxalate digestibilities in both trials (73–88%) (P < 0.05). Key words: Oxalate, calcium, forages, ponies
EFFECTS OF BLAST-CHILLING CARCASSES OF DIFFERENT WEIGHT AND FATNESS ON THE APPEARANCE OF FRESH PORK
Authors: JONES S. D. M. , TONG A. K. W. , MURRAY A. C.
Published: March 2010

Pork carcasses (n = 773) were selected at random from the moving rail of a federally inspected abattoir approximately 35 min following slaughter. All carcasses were weighed and measured for fat thickness by a ruler on the mid-line of the carcass at the point of maximum fat depth over the loin. One side of each carcass was conventionally chilled for 24 h at 1 °C. The other side was blast-chilled at −25 °C in a blast-chilling tunnel for approximately 1 h followed by 23 h of cooling at 1 °C. Left and right sides were alternated for each chilling treatment. Following the chilling period pork sides were fabricated into the major primal cuts. Boneless pork loins and whole hams were subjectively assessed for muscle color (1 = very pale, 5 = very dark) and structure (1 = extremely soft and exudative, 5 = firm and dry) using established standards. Blast-chilled loins were significantly darker (P < 0.001) and had a firmer structure (P < 0.01) than conventionally chilled loins. Ham color was also darker (P < 0.001) for the blast-chill treatment but chilling treatment had a less clear effect (P = 0.07) on ham structure. Chilling treatment effects were similar (P > 0.22) on carcasses of different weight and depths of subcutaneous fat. It was concluded that blast-chilling carcasses resulted in fresh pork with a darker color and slightly firmer structure than carcasses chilled in a conventional manner. Key words: Carcass, pork, quality, blast-chilling, PSE, DFD
EFFECT OF REPEATED IMPLANTATION WITH ZERANOL FROM BIRTH OR WEANING ON GROWTH AND REPRODUCTION IN BEEF HEIFERS
Authors: COHEN R. D. H. , NICHOLSON H. H. , JANZEN E. D.
Published: March 2010

Liveweight, pregnancy rate, skeletal development and carcass characteristics were measured on 52 crossbred beef heifers implanted with zeranol at birth then at 110, 204 and 314 d of age (B); at weaning (204 d of age) and at 314 d of age (W); or not implanted (C). At 14 mo of age, the heifers were bred for 6 wk in corrals by natural service. Six weeks later they were slaughtered and their reproductive tracts collected. Height at the withers and pelvic area were measured before slaughter. Mean weaning weights ± SD, corrected to 200 d and for age of dam, were 249 ± 20 kg for group B and 226 ± 22 kg for groups W and C (P < 0.001). At breeding, the heifers weighed 434 ± 24, 416 ± 29 and 392 ± 31 kg for groups B, W and C, respectively (P < 0.001). At slaughter, their liveweights were 531 ± 26, 508 ± 32 and 483 ± 36 kg, respectively (P < 0.001) and carcass weights were 304 ± 17, 286 ± 21 and 270 ± 20 kg, respectively (P < 0.001). Rib eye area was 84.3 ± 8.47, 76.5 ± 8.89 and 72 ± 7.81 cm2, respectively (P < 0.001) but there were no significant differences between groups for cutability (58.2 ± 1.85%), average fat cover (9.4 ± 0.84 mm) or grade (90.3% ± A1/A2 and 9.7% A3/A4). Height at the withers did not differ between groups (46.7 ± 1.61 cm) but zeranol increased pelvic area (186.4 ± 19.54, 178.6 ± 21.84 and 165.3 ± 21.14 cm2 zeranol for groups B, W and C, respectively; (P < 0.05). Pregnancy rate was significantly reduced (P < 0.05) in group B (42.9%) compared with groups W and C (84.2 and 77.8%, respectively). However, examination of the reproductive tracts indicated that only one nonpregnant heifer in each of groups B and C was not cycling and no other abnormalities were found. It was concluded that zeranol will increase live and carcass weights, rib eye area and pelvic area of heifers but that four implants given at birth and at approximately 100-d intervals to 314 d of age will reduce reproductive rate in comparison to heifers implanted twice postweaning or not implanted. Key words: Zeranol, heifer, growth, reproduction, pelvimetry, carcass
A MODIFIED METHOD FOR DETERMINATION OF IN SITU RUMEN DEGRADATION OF FEEDSTUFFS
Authors: BOER G. DE , MURPHY J. J. , KENNELLY J. J.
Published: March 2010

In situ rumen dry matter (DM) and crude protein (CP) disappearance of various feed-stuffs was studied in Holstein cows. Comparisons of nylon bag size, method of containment within the rumen, and washing technique were made to develop a system which would reduce labor and improve precision among and within laboratories. Bags (7.0 × 11.0 cm) were suspended individually in the rumen by fishing line, or placed in a polyester mesh bag before being put in the rumen. No differences were observed between method of suspension in the rumen. The polyester mesh bag was then used to contain two nylon bag types (3.5 × 5.5 cm, 1-g sample (BT1); 7.0 × 11.0 cm; 5-g sample (BT2)) for incubation in the rumen. Small bags (BT1) were heat-sealed. Dry matter and CP disappearances from BT1 were lower than from BT2. These differences were attributed to washing technique as the larger bag (BT2) was washed more vigorously. A mechanical washing wheel was designed and built to reduce variability due to washing by hand. Bags washed by machine followed by hand washing had slightly higher DM and CP disappearances than bags washed by machine only; however, these differences did not significantly influence effective degradability. Feedstuffs were reincubated in small bags and large bags, and bags were mechanically washed. Dry matter and CP disappearance and effective rumen degradabilities of DM- and CP, assuming a constant rate of outflow, were not significantly different between bag types. Use of heat-sealed small bags (3.5 × 5.5 cm), containing 1-g samples incubated in the rumen within a polyester mesh bag, and a mechanical washer, provides a system for measuring in situ DM and CP disappearance from nylon bags which reduces labor input, can potentially improve consistency among and within laboratories, and facilitates high sample throughput. Key words: In situ, rumen, degradability, mechanical washer, Holstein cows
EFFECT OF DIBASIC CALCIUM PHOSPHATE (AD LIBITUM) AND FEED TEXTURE ON THE GENERAL PERFORMANCE AND INCIDENCE OF LEG ABNORMALITIES OF ROASTER CHICKENS
Authors: HULAN H. W. , PROUDFOOT F. G.
Published: March 2010

A randomized complete block experiment was designed to evaluate the factorial effects of free-choice feeding of dibasic calcium phosphate and feed texture on general performance and incidence of leg abnormalities of roaster chickens. A total of 2000 male day-old Ross × Arbor Acre chicks were randomly assigned to 20 pens (14.61 m2) of 100 birds per pen. Ten pens of birds were randomly selected and provided dibasic calcium phosphate (DCP) ad libitum for the entire experiment. All birds were fed the starter diet in crumble form from 0 to 21 d of age (0–21 d). Five feed texture treatments (Mash; 100% Pellets (P); 95% P:5% Fines (F); 75% P:25% F; 50% P:50% F) were superimposed at 22 d of age on the mineral treatments. DCP ad libitum resulted in increased Ca and P intake, reduced Ca:aP ratio, reduced body weights, at 21 d only, higher overall mortality, incidence and severity of tibial dyschondroplasia (TD) and total leg abnormalities and (numerically) lower monetary returns. Roasters fed pelleted grower and finisher diets were heavier, at 51 d only, had (numerically) poorer feed conversion, higher incidence and severity of TD and a higher incidence of mortality due to Sudden Death Syndrome (SDS) compared with mash-fed birds. The effect of feed texture had significant trends on body weight (51 d only), DCP, Ca, P and aP intake, Ca:aP ratio, angular deformity of the tibia, TD and SDS. Although mean monetary returns were not significantly affected (P > 0.05) by the feed texture treatments applied, mash-fed birds realized on average 9.5C per bird more than birds fed pellets. Roasters raised on mash diets after 22 d reached market weight of 3.2 kg in 70 d. Key words: Calcium phosphate, feed texture, leg abnormalities, roasters
THE REPLACEMENT VALUE OF CANOLA MEAL FOR SOYBEAN MEAL IN POULTRY DIETS
Authors: LEESON S. , ATTEH J. O. , SUMMERS J. D.
Published: March 2010

The effects of replacing between 0 and 100% of dietary soybean meal with canola meal was investigated using broiler chicks and laying hens. At the highest inclusion levels, canola meal accounted for 38 and 25% of the diet of broilers and layers, respectively. For broiler chicks, there was no effect of the dietary treatments on feed intake, weight gain or feed efficiency (P > 0.05). Canola meal replaced 100% of dietary soybean meal without any significant effect on protein, fat, calcium, phosphorus or magnesium retention and energy utilization. There was also no significant effect of replacing soybean meal with canola meal on fecal soap concentration, bone ash and bone calcium, phosphorus and magnesium content. There was no significant effect of replacing all dietary soybean meal with canola meal on performance, nutrient retention and bone mineralization in laying hens (P > 0.05). These results suggest that canola meal can replace soybean meal without any adverse effects on general performance, nutrient retention or mineral metabolism of chicks and laying hens. Key words: Canola meal, broiler, layer, performance, nutrient retention
CARCASS COMPOSITION AND PROTEIN UTILIZATION OF EMBDEN GEESE FED VARYING LEVELS OF DIETARY PROTEIN SUPPLEMENTED WITH LYSINE AND METHIONINE
Authors: SUMMERS JOHN D. , HURNIK GERTRAUDE , LEESON S.
Published: March 2010

Three hundred and twenty sexed Embden geese were reared in litter floor pens to study the influence of dietary protein level and amino acid supplementation on weight gain and carcass composition. There was no difference in weight gain, to 9 wk of age, in response to dietary protein levels varying from 16 to 22%, or with methionine and lysine supplementation of these diets. Diet also had no effect (P > 0.05) on yield of various carcass parts or the chemical composition of these parts. Compared to the chicken broiler of a comparable age, a much greater proportion of the weight gain of the goose can be attributed to fat deposition. The ability of the goose to consume large quantities of feed may make it an interesting model in using forage material for the production of edible carcass protein. Key words: Goose, carcass composition, edible protein yield
EVALUATION OF THE DESTRON PG-100 ELECTRONIC PROBE FOR GRADING WARM PORK CARCASSES
Authors: USBORNE W. R. , MENTON D. , McMILLAN I.
Published: March 2010

The Destron PG-100 electronic grading probe was evaluated for prediction of lean yield, comparison with the ruler measurement, and precision on 204 pork carcasses representing equal numbers of barrows and gilts and a warm carcass weight range of 56.8–111.4 kg. A complete cutout was done on the left side from each carcass to determine a regression equation for prediction of lean yield from the probe measurements of thickness of fat and muscle between the 3rd and 4th last rib, 7 cm off the mid-line. The Hennessy probe was used as the standard for this study. Both probes performed equally well when compared with the ruler measurement and in their ability to predict lean yield. Key words: Electronic grading, pork carcasses, pork grading
THE GROWTH AND ECONOMIC PERFORMANCE OF PRECONDITIONED CALVES AND THEIR DAMS ON THE FARM AND OF CALVES IN THE FEEDLOT
Authors: KARREN D. B. , BASARAB J. A. , CHURCH T. L.
Published: March 2010

A study was conducted to evaluate the effects of preconditioning beef calves. In 1982, each of two producers allocated 100 cow-calf pairs to the study while in 1983, 130 cow-calf pairs were included on Farm 1 and 151 on Farm 2. In 1982, approximately even numbers of cow-calf pairs were randomly assigned to either a preconditioning (PC) or a regular (RG) program. These same groups were maintained in 1983. The length of the period from early weaning to shipment (preconditioning period) was 30 d (PC30) in 1982 and either 30 or 42 d (PC42) in 1983. At the end of the preconditioning period, calves from both farms were shipped to the same feedlot for 68- and 95-d tests in 1982 and 1983, respectively. PC calves gained faster than RG calves during the preconditioning period in five of the six farms by year by treatment situations. Preconditioning calves for 42 d rather than 30 d had no effect on either preconditioning gain or farm to feedlot weight loss. The cost of preconditioning ranged from $29.65 to $38.77 head−1 for PC30 calves and from $41.95 to $49.08 head−1 for PC42 calves. The price differential required by the cow-calf producer to break-even on PC calves ranged from + 5.0C kg−1 for PC30 calves to + 11.0C kg−1 for PC42 calves. Weaning treatment had no effect on either pregnancy rate the following year or on calving interval. In 1982 RG calves gained 0.13 kg d− more in the feedlot than PC30 calves. In 1983 PC30, PC42 and RG calves gained similarly. Treatment for illness of PC30 calves during the feedlot phase was 13.7% lower than RG calves in 1982. In 1983, treatment rate was reduced 42.0% for PC30 calves and 60.6% for PC42 calves. Preconditioning for 42 d rather than 30 d had no effect on feedlot growth or health performance. Cost of gain was 5.0C kg−1 less for PC calves than for RG calves in both 1982 and 1983. Key words: Calves (beef), weaning (early), preconditioning, farm, feedlot
OPERANT CONTROL OF THE THERMAL ENVIRONMENT AND LEARNING TIME OF YOUNG CHICKS AND PIGLETS
Authors: MORRISON W. D. , McMILLAN I. , AMYOT E.
Published: March 2010

Eight-day-old chicks and newly weaned piglets were used in 56 and 32 groups respectively, involving operant procedures. In each group, six chicks and six piglets were placed in a chamber adapted for the particular species and equipped with a microswitch whereby the animals could activate heat lamps. The time required for the animals to reach the criterion of learning to control the operation of the heat lamps varied from 1 h to 25 h with a mean of 7.38 h (SD 7.12 h) for the chicks, and from 1 h to 22 h with a mean of 4.4 h (SD 3.79 h) for the piglets. Failure to reach the learning criterion within 25 h occurred in five groups of chicks out of 56 and two groups of piglets out of 32. Seventy-five percent of the groups of chickens learned within 12 h while 84% of the groups of piglets learned within the first 6 h. Key words: Operant, thermoregulation, chicks, piglets, learning
EFFECT OF TIME OFF FEED ON BLOOD ACID-BASE HOMEOSTASIS IN PIGS DIFFERING IN THEIR REACTION TO HALOTHANE
Authors: SCHAEFER A. L. , DOORNENBAL H. , TONG A. K. W. , MURRAY A. C. , SATHER A. P.
Published: March 2010

In an effort to elucidate physiological factors involved in the development of pale-soft-exudative pork, blood acid base status was assessed in swine from two genetic lines of pigs and their F1 cross. The lines consisted of: (1) pigs that reacted positively (skeletal muscle rigidity) to the respiratory administration of halothane (halothane positive (H+)) based on Pietrain × Lacombe breed crosses, (2) Purebred Lacombe pigs that did not react positively to halothane anesthesia (Lac) and (3) pigs which were the progeny of crossbreeding (C) between halothane positive and negative animals. In addition, time off feed prior to slaughter (0, 24 or 48 h) was imposed as a stressor in order to test response differences among the three lines. The venous blood PCO2, total CO2, bicarbonate ion levels, standard bicarbonate and base excess levels were found to be higher in the H + pigs compared to either Lac or C pigs. All pig lines displayed higher blood pH, total CO2, bicarbonate ion, standard bicarbonate and base excess yet lower PO2 at 24 h off feed compared to 0 h off feed. These data suggest that H+ pigs have a greater tendency toward hypercapnia and a blood base excess than either Lac or C pigs. In addition, the incidence of hypercapnia and blood base excess for H +, Lac and C pigs was greatest at 24 h off feed. Key words: Acid-base stability, pig genotypes, fasting
EFFECT OF ANABOLIC IMPLANT AND IONOPHORE ON THE PERFORMANCE OF GRAZING STEERS
Authors: RODE L. M.
Published: March 2010

In a 110-d grazing study, 75 yearling steers were left unimplanted or implanted at Day 0 with 24 mg 17β-estradiol, 36 mg zearanol, 72 mg zearanol, or 36 mg zearanol at Day 0 and 84. Within each implant group, steers were also supplemented with barley (0.5 kg head−1 d−1) with or without lasalocid (0.75 mg kg body weight−1 d−1) or were given no supplement in a 5 × 3 factorial design. Average daily gain (ADG) for all implanted steers was 17.5% greater (0.94 vs. 0.80 kg d−1) than for unimplanted steers (P < 0.01). Increasing the dosage of zearanol from 36 to 72 mg extended the time over which ADG was increased but total liveweight gain and ADG over the 110-d grazing season were similar for all implant types. A second implant of zearanol (2 × 36 mg) increased ADG during the final 26 d of the pasture phase and during the drylot period, compared with 72 mg zearanol given initially. Barley + lasalocid-supplemented steers had ADG 17.3% greater (1.02 vs. 0.87 kg d−1) than barley-supplemented steers (P < 0.01). During the following drylot phase, when no lasalocid was fed, ADG was lower (P < 0.10) for steers that had previously received lasalocid than for other groups. No interactions were observed between implant and supplement type. Thus, the anabolic implants and ionophores used in this study are additive in improving growth rate. Key words: Cattle, feedlot, grazing, lasalocid, zearanol, 17β-estradiol, growth
SEASONAL VARIATION IN SERUM β-CAROTENE AND VITAMIN A AND THEIR ASSOCIATION WITH POSTPARTUM REPRODUCTIVE PERFORMANCE OF HOLSTEIN COWS
Authors: TEKPETEY F. R. , PALMER W. M. , INGALLS J. R.
Published: March 2010

Two groups of winter-housed cows (eight cows per group) that calved in winter/spring (Group 1) and summer/fall (Group 2) were used to assess the effect of seasonal variation in serum/3-carotene and vitamin A concentrations on postpartum reproductive performance. The cows maintained adequate levels of serum β-carotene (240 ± 14–339 ± 19 mg dL−1) from fall to spring when fed various combinations of hay, silage, haylage and alfalfa pellets. There was an increase (P < 0.05) in serum β-carotene and vitamin A concentrations during summer when the cows were on pasture. Average interval to first ovulation postpartum and services per conception did not differ between the two groups. However, interval for uterine involution, interval to first service and average number of days open were improved in Group 2 cows. Partial correlations were not found between serum β-carotene and vitamin A concentrations during the calving period and any of the reproductive parameters (P > 0.05). Although there was seasonal variation in serum β-carotene and vitamin A concentration, the levels throughout the trial were generally adequate and hence did not affect reproductive performance. Key words: β-carotene, vitamin A, reproductive performance, dairy cows
ROLE OF SOAP FORMATION IN UTILIZATION OF FULL-FAT CANOLA BY LAYING HENS
Authors: ATTEH J. O. , LEESON S. , SUMMERS J. D.
Published: March 2010

Laying hens (35 w old) were offered diets containing 0, 5, 10, 15 or 20% full-fat canola over an 8-wk period. There were no significant effects of the dietary treatments on egg production, egg weight or egg shell quality (P > 0.05). Although laying hens fed each of the diets consumed similar quantities of feed (P > 0.05), birds consuming diets containing 15 or 20% full-fat canola gained less weight compared to birds fed lower levels of full-fat canola (P < 0.01). There was no difference among treatments for apparent retention of nitrogen, calcium, phosphorus or magnesium (P > 0.05) However there was a decrease in both fat retention and energy utilization with an increase in dietary level of full-fat canola (P < 0.01). There was no difference in the fat content of the eggs as affected by the dietary treatments and with the exception of a decrease in proportion of palmitic acid (P < 0.05) and increase of linolenic acid (P < 0.05) increased inclusion of full-fat canola had little effect on egg fatty acid content. There was no significant effect on the dietary treatments on bone ash and bone mineral content. These data suggest that while high levels of full-fat canola have little effect on performance during short-term studies, there is concern of the birds' ability to digest canola lipids. Key words: Full-fat canola, laying hen, bone mineralization
RESPONSE OF WHITE LEGHORNS TO DIETS CONTAINING GROUND OR WHOLE TRITICALE
Authors: LEESON S. , SUMMERS J. D.
Published: March 2010

Growing leghorn pullets and laying hens were fed diets containing triticale as the sole cereal source. Body weight of pullets was not affected (P > 0.05) by up to 70% dietary inclusion of triticale. When layer diets contained 70% whole or ground triticale in place of corn, egg production was depressed (P < 0.05) while birds consumed more feed (P < 0.05). The feed intake effect is discussed in relation to the energy value of triticale. Key words: Triticale, pullets
DIURNAL PATTERNS OF ESTROUS BEHAVIOR OF DAIRY COWS HOUSED IN A FREE STALL
Authors: AMYOT E. , HURNIK J. F.
Published: March 2010

Sixteen primiparous and fifteen multiparous cows housed in a free-stall area with slatted floor alley were observed continuously for 100 d postpartum using a time-lapse videorecorder. Low intensity (< than 3 lx) red lights were used for nocturnal illumination. Natural daylight from an existing window and incandescent lamps provided daytime illumination (12–52 lx). The analyses focused on the periestrous period beginning 2 d prior to and ending 2 d after estrus. Onset of true estrus was most frequent between 1200 and 1800 h in the primiparous group (35%) and between 0600 and 1200 h in the multiparous group (37%). A nadir of true estrus onset (15%) occurred between 1800 and 2400 h in both groups. The predominant hours of estrual activities occurred during daylight, between 1500 and 1800 h in the primiparous group and between 0900 and 1100 h in the multiparous group. In general, the daily distribution of estrous activities had a quadratic shape and these shapes or patterns of estrous activities were remarkably consistent among cows and estruses. Among the monitored estrual activities, mounting, sniffing and chin pressed in the primiparous group, and chin pressing, chin pressed, mounting, mounted and sniffed in the multiparous group, were found to best discriminate the cows' behaviors on estrous day with their behaviors on the 2 days pre- and postestrus. Key words: Reproductive behavior, sexual behavior, estrous behavior, cow behavior, cow (dairy)
LIMITED NURSING EFFECTS ON REPRODUCTIVE PERFORMANCE OF PRIMIPAROUS AND MULTIPAROUS COWS AND PREWEANING CALF PERFORMANCE
Authors: HILL G. M. , GODKE R. A.
Published: March 2010

Effects of limited nursing and parity of the dam on cow reproductive and calf gain performance were determined in two experiments involving 97 beef cow-calf pairs. Fall-calving (exp. 1) and spring-calving (exp. 2) primiparous (P) and multiparous (M) cows were assigned to control (C) or limited nursing (L) treatments at 21–28 d postpartum. Cows and calves continued on nursing treatments until first estrus was detected, or until 42 d had elapsed. Nursing treatment and parity of the dam influenced estrous activity in exp. 1. Higher (P < 0.05) percentages of multiparous dams and of L treatment cows were observed in estrus during the treatment period. A 5.6-d reduction (P < 0.10) in postpartum interval to first estrus (PPI) was observed for L cows observed in estrus during treatment periods, and a 16.2-d reduction (P < 0.01) occurred for L cows when all cows observed in estrus during or after the nursing treatment periods were compared to control cows in exp. 1. In exp. 2, nursing treatment and parity of the dam did not significantly affect PPI. Nursing treatments did not affect pregnancy rates in exp. 1, but M cows had higher (P < 0.01) pregnancy rates than P cows. Average daily gains (ADG) were lower (P < 0.10, exp. 1; P < 0.01, exp. 2) for L calves compared with C calves during treatment periods. The L calves did not overcome ADG reductions suffered while on the L treatment by weaning time, and 205-d adjusted weights of L calves were 25 kg lower (P < 0.05) than C calves in exp. 1. Potential improvement in reproductive efficiency resulting from limited nursing must be evaluated with regard to reduced preweaning calf performance. Key words: Cattle (beef), postpartum interval, estrus, once-daily nursing, weaning weight, first estrus
EFFECTS OF SOYFLOUR IN MILK REPLACER ON THE PERFORMANCE OF ARTIFICIALLY REARED LAMBS
Authors: HEANEY D. P. , SHRESTHA J. N. B.
Published: March 2010

Two artificial rearing experiments were conducted to evaluate both preweaning and postweaning performance of artificially reared lambs, ad libitum fed a milk replacer having one-third of the milk protein replaced by soyflour protein (S) compared with those fed MR with all the protein provided by milk products (M). From weaning at 21 d of age to 91 d of age all the lambs were fed the same high-concentrate diet. In the first experiment there were no significant differences in lamb weights, daily gains, postweaning feed conversion or lamb survival. In the second experiment there were lower (P < 0.05) postweaning daily gains, lower (P < 0.05) 91-d weights and higher (P < 0.05) postweaning feed conversion (2.69 vs. 2.52 kg feed kg−1 gain) for S lambs compared with M lambs, although there were no significant differences due to MR treatment for weaning weights, preweaning daily gains or lamb survival. In both experiments the S lambs consumed slightly more MR than M lambs. Using prices prevailing at the time of the study the lower ingredient cost of the soyflour resulted in a saving in MR cost of $1.45 per lamb weaned. In the second experiment, the lower MR cost would have been partially offset by the approximately 1 kg extra liveweight per lamb at 91 d of age. It was concluded that soyflour could contribute one-third of the total protein in MR for ad libitum fed, artificially reared lambs with little, if any, reduction in lamb performance. However, savings in feed costs resulting from the cheaper ingredient cost might be partially offset by lower postweaning lamb gains. Key words: Lambs, artificial rearing, milk replacer, soy protein
GEOGRAPHICAL VARIATION OF THE TOTAL SULFUR CONTENT OF FORAGES GROWN IN NORTHWESTERN MANITOBA
Authors: BOILA R. J. , DEVLIN T. J. , WITTENBERG K. M.
Published: March 2010

In a forage survey of northwestern Manitoba, total sulfur (S) in grass (n = 600) and legume (n = 262) samples ranged from less than 0.1 to as high as 7.8 g kg−1 dry matter (DM) with mean concentrations in the range of 2.0–2.7 and 2.5–3.4 g kg−1 DM, respectively. Deficiencies of total S for cattle are more likely to occur with grasses while excesses are more likely to occur with legumes. Excessive concentrations of total S, in addition to high or excessive molybdenum in forages, may contribute to the hypocupremia encountered in cattle herds throughout Northwestern Manitoba. Identification of locations where forages may contain excessive total S and/or molybdenum aids in the development of forage and livestock management programs necessary to prevent or reverse hypocupremia in cattle herds. Key words: Forages, sulfur, cattle, copper, molybdenum, northwestern Manitoba
EFFECTS OF DATE OF WEANING ON POSTWEANING PERFORMANCE OF BULL CALVES OF THREE BREED GROUPS
Authors: KUBISCH H.-M. , MAKARECHIAN M.
Published: March 2010

The effects of weaning date on feedlot performance and carcass characteristics of 367 bull calves weaned 1 mo apart were compared in a 2-yr study at the University of Alberta ranch at Kinsella, Alberta. The calves belonged to three distinct breed groups. Calves were weaned either on 1 Oct. or 1 Nov., at which time they averaged 157 ± 1.5 and 189 ± 1.7 d of age, respectively. After a 4-wk postweaning adjustment period, calves in each group were fed a mixed diet containing 90% concentrate and 10% hay. During the period between the two weaning dates early-weaned calves gained more (P < 0.05) than their unweaned contemporaries, while the performance of the two groups during their respective adjustment periods was similar. The late-weaned group gained 175 g d−1 more (P < 0.05) and consumed 800 g d−1 more feed (P < 0.05) during the 140-d feedlot test while feed efficiency did not differ between the two groups. Average daily rate of gain from birth to 1 Oct. had a significant influence on feedlot gain (b = 0.42). Although late-weaned calves had a higher rate of growth during the feedlot test, their early-weaned contemporaries were 14.3 kg heavier and 7 d younger at slaughter. Significant differences in gain and carcass traits were observed between the three breed groups, but the interaction between breed group and weaning date was not significant, indicating that calves of different genetic backgrounds respond similarly to the effects of age at weaning. The results indicate that under Alberta's climatic conditions and despite lower feedlot gains, weaning calves 1 mo early is a viable alternative to the customary weaning date. Key words: Beef calves, bulls, weaning date, carcass traits
THE EFFECTS OF THE STRESS OF WEANING AND TRANSIT ON PERFORMANCE AND METABOLIC PROFILE OF BEEF CALVES OF DIFFERENT GENOTYPES
Authors: PHILLIPS W. A. , JUNIEWICZ P. E. , ZAVY M. T. , TUNGELN D. L. VON
Published: March 2010

Feeder calves of Bos indicus or Bos taurus breeding, reared under the same management and environmental conditions, were subjected to the stressors of weaning, assembly and transport to determine if genotype of the calf had a significant impact on stress responsive parameters. These responses were measured by monitoring changes in body weight, poststress dry matter intake and selected metabolic factors. Calves lost 11 kg or 8.1% of their weaning body weight during assembly and transit. Genotype was not related to weight changes during assembly and transit; however, Hereford × Brahman calves gained less (P < 0.05) weight during the 28-d post-transit period than Angus × Brahman or Angus × Hereford calves. Serum glucose, urea nitrogen, total protein, potassium and sodium concentrations were altered (P < 0.05) by weaning or transport and were generally higher (P < 0.05) in the half Brahman calves than the Angus × Hereford calves. Within the context and conditions of this experiment, genotype was not related to the metabolic response of the beef calf to the stresses associated with weaning and transport. However, genotype was found to influence basal nonstressed metabolic values indicating that poststress metabolic measurements alone may be misleading as an indication of the physiological response to stress. Key words: Cattle, stress, genotype, glucose, protein, urea
EFFECTS OF DIETARY MOLYBDENUM ON PRODUCTIVITY AND METABOLIC PARAMETERS OF LACTATING BEEF COWS AND THEIR OFFSPRING
Authors: WITTENBERG K. M. , DEVLIN T. J.
Published: March 2010

A study was undertaken to determine cow lactation and suckling calf growth responses to varying concentrations of molybdenum (Mo) in the diet of lactating beef cows. Twelve cow-calf pairs, at approximately 31 d postcalving, were assigned to one of three dietary treatments for 9 wk. The experimental design was a split-plot with dietary treatment at the whole plot level and time (wk) at the subplot level. Cows were group fed 11.6 kg dry matter (DM) d−1 of their respective diets which contained corn silage and barley in a ratio of 77: 23, DM basis. Mo, as ammonium molybdate [(NH4)6 Mo7O24∙4H2O] was added to the barley such that Mo concentration in the diets was 0.60 (0Mo),19.3(20Mo) and 34.8 (40Mo) mg kg−1 DM. Nutrient composition of the diets averaged 14.3% crude protein, 0.52% calcium, 0.38% phosphorus, 0.13% sulfur and 5.9 mg kg−1 copper (Cu), DM basis. No feed was offered to calves. Cow milk yield and composition, cow and calf body weight and cow and calf blood samples were obtained weekly. Liver biopsies were performed in calves during weeks 1, 4 and 9. Milk yield, determined by an oxytocin/hand milking method, declined more rapidly (P < 0.05) for cows consuming 40Mo than for 0Mo or 20Mo. Diet did not influence fat, protein, lactose and Cu concentrations in milk (P > 0.05) but milk Mo concentration increased (P < 0.05) with each increment in dietary Mo. Cows given the 40Mo diet had a more rapid decline (P < 0.05) in plasma Cu concentration and ceruplasmin (Cp), a principal cupro-enzyme in plasma, activity than cows given the 0Mo and 20Mo diets. Cow plasma Mo concentrations were increased with each increment in dietary Mo (P < 0.05). Reduced milk yield and increased milk Mo levels caused lower (P < 0.05) calf average daily gains, but did not influence calf plasma Cu, Cp or liver Cu concentrations. Key words: Cow, calf, lactation, molybdenum, copper
INFLUENCE OF CECECTOMY AND DIETARY ANTIBIOTICS ON THE FATE OF INGESTED INTACT GLUCOSINOLATES IN POULTRY
Authors: SLOMINSKI B. A. , CAMPBELL L. D. , STANGER N. E.
Published: March 2010

A series of experiments involving the use of cecectomized hens and dietary antibiotics as means of controlling hindgut fermentation was conducted to follow the disappearance of intact glucosinolates (IG) from the GI tract of poultry. In addition, a balance study was conducted with colostomized roosters to determine the role of the kidney in the excretion of IG and thiocyanate ion (SCN). Recovery of IG in cecectomized hens was significantly (P < 0.05) higher than in intact hens (80.5 vs. 33.6 mmol 7 d−1). Similarly, IG recovery was significantly (P < 0.05) higher in antibiotic-fed hens than in hens fed no antibiotics. The effect varied among antibiotics with chlorotetracycline and lincomycin showing the greatest response. Both aliphatic and aromatic (glucosinalbin and indoles) IG disappeared from the GI tract to a significantly (P < 0.01) greater extent in intact hens than in cecectomized hens but the absolute amount of disappearance was greater for aliphatic IG than for aromatic IG. Thiocyanate ion (SCN) excretion was high in the urine of colostomized roosters fed canola meal and exceeded intake in antibiotic-fed, cecectomized hens. The biotransformation of absorbed aliphatic IG was indicated as a possible source of the excess SCN. Key words: Poultry, glucosinolates, absorption, cecectomy, antibiotics, thiocyanate ion
HYDROLYSIS OF THE CYANOGENIC GLYCOSIDES AMYGDALIN, PRUNASIN AND LINAMARIN BY RUMINAL MICROORGANISMS
Authors: MAJAK W. , CHENG K.-J.
Published: March 2010

Three cyanogenic glycosides were incubated simultaneously but separately in rumen fluid from cattle to determine the rates of glycoside hydrolysis. The average rates for prunasin were significantly higher than those for linamarin or amygdalin. Production of HCN from linamarin occurred in 25 out of 50 strains of rumen bacteria tested. Key words: Cyanogenesis, rumen bacteria, linamarin, amygdalin, prunasin, cattle diets
NUTRITIONAL AND HORMONAL INTERRELATIONSHIPS IN BEEF CATTLE REPRODUCTION
Authors: SHORT R. E. , ADAMS D. C.
Published: March 2010

Reproductive rate has a major influence on production efficiency of beef cattle, and nutritional management is the main limiting or controlling factor for reproduction. Decreased availability of energy is the most common problem studied in beef cattle management and will be the primary focus of this review. In order to effectively manage energy nutrition, we need a better understanding of how this variable affects the various phases and control mechanisms of reproduction. Insufficient energy intake because of dietary quality or quantity will delay puberty, lengthen postpartum anestrus and cause anestrus in cows or heifers that are having estrous cycles. Energy intake has effects on a wide variety of endocrine, neural and metabolic mechanisms. Effects include changes in gonadotropic hormone secretion from the pituitary, production of progesterone during both the estrous cycle and pregnancy, differential sensitivity of the pituitary-hypothalamus to steroids and releasing hormones and changes in ovarian activity measured by hormone secretion, follicular development and ovulation. All of these effects of dietary energy have been shown to be variable. This variation in response seems to be related to differences in degree of energy restriction, body condition score and whether body weight is stabilized or changing. Glucose may be the specific energy source through which energy manifests its effects on reproduction. Key words: Beef cattle, nutrition, reproduction, hormones, energy