bluuebunny/crossref_metadata_2025 huggingface dataset:
LIVE BODY MEASUREMENTS IN TEN FIRST CROSSES OF BEEF COWS RAISED IN TWO ENVIRONMENTS
Authors: McKAY R. M. , RAHNEFELD G. W. , WEISS G. M. , FREDEEN H. T. , LAWSON J. E.
Published: March 2010

Live body measurements on beef cows representing 10 F1 crosses were recorded in 1976 (890 cows) and 1980 (586 cows) at Brandon, Manitoba and Manyberries, Alberta. The crosses included the Hereford × Angus (HA) and crosses sired by Charolais, Limousin, and Simmental bulls out of Angus, Hereford, and Shorthorn dams. Cows were classified into three nursing status groups in 1976, dry-nursing, nursing-dry, and nursing-nursing, only two groups in 1980, dry-nursing and nursing-nursing. The group refers to the status in the year prior to the measurements and the year of measurement, respectively. The objectives of the study were: (1) to compare the HA to the exotic crosses and determine differences among the exotic crosses; (2) to evaluate the effect of nursing status on the live cow measurements; (3) to study the differences between the two locations; and (4) to relate the size of the cows in 1976 relative to their size in 1980. Exotic cross cows were higher at the withers and hips, longer, heavier at weaning, and had less subcutaneous fat cover than HA cows. Differences among the exotic crosses were found for all traits in both years with the exception of subcutaneous fat cover in 1980. Possible genotype × environment interactions were observed as a cow cross × nursing group interaction was found for subcutaneous fat cover at both locations in the 1976 data and a cow cross × location interaction for body length in the 1980 data. Nursing status affected cow weight at weaning, subcutaneous fat cover, height at the withers, and body length in the 1976 data but only cow weight at weaning and subcutaneous fat cover in the 1980 data set. Differences between locations were found for cow weight at weaning and height at the withers in 1976, and subcutaneous fat cover and body length in 1976 and 1980. Cows at Brandon achieved a greater proportion of their mature body size by 1976 than their contemporaries at Manyberries for all traits measured. Key words: Cattle (beef), breed crosses, cow, body measurements, genotype environment interaction
EFFECTS OF INJECTION OF GONADOTROPIN-RELEASING HORMONE ON SOW FERTILITY
Authors: GOONERATNE A. D. , KIRKWOOD R. N. , THACKER P. A.
Published: March 2010

A total of 159 Landrace × Yorkshire sows were used to study the effects of an intramuscular injection of gonadotropin-releasing hormone (GnRH) at estrus on reproductive performance. Artificial insemination at 24 h or 24 and 40–44 h following treatment, resulted in similar conception rates for GnRH-treated (77.5 and 69.2%) and control sows (70.0 and 67.5%). Conception rates were not affected by insemination regime. GnRH treatment resulted in slightly improved litter sizes in comparison with control sows (10.45 vs 9.92; P > 0.20) whether inseminated once or twice, but had no effect on piglet weight at birth. Litter size and piglet weight at weaning were also not influenced by treatment. GnRH treatment (100 μg) induced increases in serum concentrations of luteinizing hormone (LH) and follicle stimulating hormone (FSH) from the anterior pituitary within 30 min and maximal serum concentrations were observed 90–120 min postinjection. The induced release of both LH and FSH was of short duration (< 4 h), compared to the natural surge of LH which followed later, coincident with estrus. It was concluded that the overall reproductive performance of sows was not significantly influenced by GnRH treatment immediately prior to estrus. Key words: Sow, GnRH, pituitary response, reproductive performance
NET BLOOD EXCHANGE OF BRANCHED-CHAIN AMINO AND α-KETO ACIDS ACROSS THE PORTAL-DRAINED VISCERA AND HINDLIMB OF CATTLE DURING INFUSIONS OF LEUCINE AND INSULIN
Authors: EARLY R. J. , THOMPSON J. R. , CHRISTOPHERSON R. J.
Published: March 2010

The effects of intra external iliac arterial infusions of leucine (114 μmol h−1 kg0.75) and insulin (0.34 U h−1 kg0.75) into the hindlimb on net whole blood branched-chain amino acid (BCAA), plasma branched-chain α-keto acid (BCKA) and glucose exchange across the hindlimb (HL) and portal-drained viscera (PDV) were investigated in chronically catheterized cattle. Leucine infusions increased (P < 0.05) arterial leucine and α-ketoisocaproate concentrations but did not affect the concentrations of other BCAA, BCKA or glucose. Leucine infusions resulted in a 4-fold increase (P < 0.1) in the net HL removal of leucine and a small increase (P < 0.1) in the net HL release of α-ketoisocaproate. Net whole blood BCAA, plasma BCKA and plasma glucose exchange across the PDV were unaffected by leucine infusions. Insulin infusions decreased (P < 0.1) whole blood leucine, plasma α-ketoisocaproate and plasma glucose concentrations and increased (P < 0.1) the HL extraction of plasma glucose. The HL and PDV extraction of whole blood BCAA and plasma BCKA were unaffected by insulin infusions. The data suggest that cattle are less sensitive to the effects of leucine and insulin on tissue BCAA catabolism compared to nonruminant species. Key words: Branched-chain amino acid, branched-chain α-keto acid, leucine, insulin, cattle
A SURVEY OF MATERNAL COPPER STATUS AND FETAL TISSUE COPPER CONCENTRATIONS IN SASKATCHEWAN BOVINE
Authors: GOONERATNE S. R. , CHRISTENSEN D. A.
Published: March 2010

Copper (Cu) status of cattle raised in different soil zones of Saskatchewan was examined with emphasis on the relation between liver Cu concentration in pregnant cows, stage of pregnancy and fetal liver Cu status. Whole fetuses and livers from adult animals were obtained during routine slaughter operation at a local packing plant. Twenty percent of steers, 54% of pregnant cows, 52% of heifers and 77% of nonpregnant cows had liver Cu levels less than 25 mg kg−1 dry matter (DM). Hypocuprosis was most marked in cattle originating from northern regions of Saskatchewan. Fetal liver Cu concentration depended on the dam liver Cu concentration and on stage of pregnancy and could be represented as: Fetal liver Cu concentration (mg kg−1 DM) = 217.5 + 0.023 [(age of fetus (days) × dam liver Cu concentraiton (mg kg−1 DM)]. During gestation the level of Cu progressively increased in the fetal liver and decreased in maternal liver. Liver Cu levels of fetuses from dams with liver Cu greater than 25 mg kg−1 DM were higher (P < 0.05) than those in fetuses from dams with liver Cu levels lower than 25 mg kg−1 DM. Dam liver Cu status did not influence fetal liver, kidney, heart and brain weights or the Cu concentration of fetal kidney, heart or brain. The magnitude of hypocuprosis in cattle in Saskatchewan is extensive and emphasizes the importance of adequate Cu nutrition in pregnant cattle with respect to maintaining acceptable fetal Cu status. Key words: Copper deficiency, Saskatchewan, soil zones, cattle, pregnancy, fetus
A SURVEY OF MATERNAL AND FETAL TISSUE ZINC, IRON, MANGANESE AND SELENIUM CONCENTRATIONS IN BOVINE
Authors: GOONERATNE S. R. , CHRISTENSEN D. A.
Published: March 2010

Whole bovine fetuses and liver and kidney from corresponding dams, from nonpregnant cows, from heifers, and from steers were collected during routine slaughter operation at a local packing plant in Saskatoon. Fetal liver, kidney, heart and brain, and liver and kidney from adult cattle were analyzed for Zn, Fe, and in some cases for Mn and Se. Pregnancy did not significantly alter the dam liver Zn, Fe, and Mn concentrations. Fetal liver Zn, Fe and Se concentrations were several-fold higher and Mn concentrations lower than those in liver from corresponding dams. Liver Se concentrations were significantly lower in the nonpregnant cows, of which 34% originated from gray black and muskeg soils in Saskatchewan. Liver Se concentrations of fetuses and pregnant cows originating from muskeg and gray (wooded) soils were significantly lower than those from other areas of Saskatchewan. Correlations between Zn, Fe, Mn, Se and Cu between and within dam and fetal tissues were low, except for dam and fetal liver Se concentration (r = 0.65). Possible interactions between these micronutrients in both the dam and fetus and sources of biases which occur in this type of a survey are discussed. Key words: Zinc, iron, maganese, selenium, cattle, pregnancy
INFLUENCE OF DIETARY COPPER, MOLYBDENUM AND SULFUR ON COPPER METABOLISM OF SHEEP
Authors: MOSHTAGHI-NIA S. A. , DEVLIN T. J. , PHILLIPS G. D.
Published: March 2010

Twenty-eight ram lambs were allotted to one of four treatment diets on the basis of body weight (34.7 ± 6.6 kg) in a split-plot design. The pelleted diet of alfalfa-bromegrass hay (31.2%), barley (63.2%) and molasses and premix (5.6%) was fed ad libitum and contained 11.5 mg copper (Cu), 2.8 mg molybdenum (Mo) and 1.8 g sulfur (S) kg−1 (dry matter) DM. The four experimental diets were: basal (diet I); basal plus 10 mg Mo and 2 g S (diet II); basal plus 10 mg Cu, 10 mg Mo and 2 g S (diet III); basal plus 20 mg Cu, 10 mg Mo and 2 g S (diet IV), per kilogram of diet DM. Copper as copper sulfate (CuSO4∙5H2O), S as anhydrous sodium sulfate (Na2SO4) and Mo as ammonium molybdate ((NH4)6Mo7O24∙4H2O) were added and provided Cu:Mo ratio of 5.0, 0.7, 1.5 and 2.0 for diets I, II, III and IV, respectively. Lambs were fed the experimental diets in confinement for 16 wk. Measurement of body weight and samples of liver tissue and blood serum were obtained every 4 wk. The treatment diets had no significant (P > 0.05) effect on body weight. Liver Cu concentration increased for the I and IV diets and declined for II and III diets (P < 0.01). Lambs on diet II had the highest (P < 0.01) concentration of serum total Cu, Mo and trichloroacetic acid (TCA) insoluble Cu relative to lambs consuming the other diets. Lambs assigned to diet I had higher (P < 0.01) serum ceruloplasmin (Cp) activity and TCA-soluble Cu levels than lambs consuming supplemented diets. Therefore, a dietary concentration of 3.3 g kg−1 S and Cu:Mo ratio of 0.7 caused high serum Cu and TCA-insoluble Cu which did not contribute to hepatic Cu reserves. Increasing the Cu:Mo ratio in the diet reversed these effects. Key words: Copper, molybdenum, sulfur, interaction, sheep
HEPATIC UREA SYNTHESIS AND SITE AND RATE OF UREA REMOVAL FROM BLOOD OF BEEF STEERS FED ALFALFA HAY OR A HIGH CONCENTRATE DIET
Authors: HUNTINGTON GERALD B.
Published: March 2010

Five Hereford × Angus steers, 240 ± 6 kg liveweight with chronic indwelling catheters in various sites in the splanchnic bed were used to evaluate effects of dietary energy source and nitrogen (N) level on urea synthesis and site and rate of urea removal from blood. Alfalfa hay (162 g N d−1) or a high concentrate diet (95 g N d−1) were fed at similar metabolizable energy intake (54.8 MJ d−1). Compared with the alfalfa, the high concentrate, low N diet decreased (P < 0.05) blood concentrations of urea N, hepatic urea synthesis, urinary urea N excretion, transfer of urea N to poststomach tissues, and salivary transfer of urea N. Similarly, the high concentrate diet decreased net absorption of ammonia N and increased net absorption of glucose from portal-drained viscera decreased hepatic removal of ammonia N and α-amino N, and increased release of α-amino N by splanchnic tissues (P < 0.01). Blood flow (dilution of para-aminohippurate) through the liver and gut was not affected (P > 0.10) by diet. A greater (P < 0.05) portion of urea synthesized in the liver was transferred to the gut when the high concentrate diet was fed. Site of total urea transfer to the gut (from blood plus saliva) shifted from 37% of total transfer into poststomach (alfalfa) to 75% into stomach (high concentrate diet). Increased intake of readily fermentable carbohydrate at the expense of N and fiber increased the percentage of liver urea synthesis recycled to the gut and focused that recycling into the stomach (rumen) in these steers. Key words: Bovine, energy, nitrogen, urea flux, gut, liver
THE FEEDING VALUE OF POTATO STEAM PEEL FOR GROWING-FINISHING PIGS
Authors: LUNEN T. A. VAN , ANDERSON D. M. , ST. LAURENT A.-M. , NICHOLSON J. W. G. , DEAN P. R.
Published: March 2010

Potato steam peel (SP) is a by-product of potato processing where the peel is removed after steaming. It typically contains 15 ± 3% dry matter, 16 ± 1% crude protein, 0.55 ±.05% lysine, 0% methionine/cystine and 6% ash (dry matter basis). Steaming effectively deactivates the proteolytic enzyme inhibitors and partially denatures the starch. SP was evaluated in a digestibility trial and at levels from 0 to 30% DM in two feeding trials. The digestibility (%) of SP by pigs was found to be 88.4 (DM), 80.1 (CP) and 86.1 (DE). In the first feeding trial diets containing levels of 0, 10, 15, 20, 25 and 30% SP supplemented with methionine resulted in similar growth performance and carcass characteristics. In the second feeding trial, a comparison was made between a constant level of inclusion and an increase in inclusion level with age. Results showed no difference in growth performance or feed consumption among treatments. It is concluded that SP can be incorporated in diets for growing-finishing pigs at levels up to 30% DM. No change in performance resulted from increasing level of inclusion with age. Key words: Potato, steam peel, pigs, digestibility
ESTIMATION OF FUNGAL CONTAMINATION OF CEREAL GRAINS AS DETERMINED BY MEASURING GLUCOSAMINE CONCENTRATION
Authors: ROTTER R. G. , FROHLICH A. A. , MARQUARDT R. R. , MILLS P. A.
Published: March 2010

The degree of fungal contamination of a grain or feed sample can be estimated from the determination of its glucosamine (GlcN) content, using a modified amino acid analysis procedure. A sample (100 mg) was hydrolyzed in 6 N HCl for 7 h at 121 °C, evaporated to dryness, reconstituted in citrate buffer and applied to an ion exchange column of an amino acid analyzer. Hydrolysis conditions were optimized for the recovery of GlcN, released by the breakdown of chitin, a major fungal cell wall component. The GlcN and galactosamine (GalN) concentrations of several species of fungi indigenous to western Canada, grown on liquid culture, were determined to provide reference values for estimating fungal contamination. A fungal contamination index (FCI) is proposed, based on a comparison of the GlcN concentration of a sample to the specific reference fungus (if the fungal species has been characterized) or an average from several species. Based on the fungal species tested, a suggested average for use with most naturally contaminated grain samples is 76 mg GlcN g−1 of fungal dry matter. This approximation would be valid for most cases of mixed or unknown fungal species. Knowing the fungal content of a grain sample will aid in feed formulation and thereby reduce costly losses to the livestock producer. Key words: Fungal contamination, glucosamine, chitin, grain, amino acid analysis
THE INFLUENCE OF EXOGENOUS GROWTH HORMONE ON OVULATION RATE IN GILTS FED DIETS WITH DIFFERENT ENERGY AND PROTEIN CONTENTS
Authors: KIRKWOOD R. N. , THACKER P. A. , LAARVELD B.
Published: March 2010

Following pregnant mare's serum gonadotrophin (PMSG) induced ovulation, 61 Yorkshire × Landrace gilts were allocated to be fed either a control or a high-energy diet for 30 d. From 14 d, gilts on each dietary treatment received nine daily injections of porcine growth hormone or vehicle. Growth hormone depressed feed intake by 30% (P < 0.001), but did not influence ovulation rate. No influence of diet or growth hormone on the incidence of a subsequent ovulation was apparent. Key words: Gilts, diet, growth hormone, ovulation rate
THE DEVELOPMENT OF A HALOTHANE-SENSITIVE LINE OF PIGS
Authors: SATHER A. P. , MURRAY A. C.
Published: March 2010

A halothane-sensitive line of pigs was developed from a Pietrain-Lacombe synthetic line through selection of breeding stock based on their sensitivity to a 4 min, 4.5% halothane challenge. It appears that halothane sensitivity is inherited by a single, autosomal recessive allele (n), that is essentially fully penetrant (0.98) in halothane-sensitive pigs (nn). The gene was fixed within four cycles of selection. Segregation at the halothane locus among the two sexes provided no evidence to suggest differential mortality between the sexes and fit inheritance patterns typical of an autosomal locus. However, litters that originated from nn × nn mating types had 1.3 fewer pigs weaned per litter than those mating types in which at least one parent carried the halothane gene. There was no evidence for any expression of halothane sensitivity in normal pigs (NN) and only infrequent expression in the heterozygote (Nn). Key words: Halothane gene, inheritance, swine
PREPARATION OF NEONATAL PIG CARCASS HOMOGENATES BY AUTOCLAVING: INFLUENCE ON PROXIMATE AND LIPID ANALYSIS
Authors: PATIENCE JOHN F. , FARNWORTH EDWARD R.
Published: March 2010

The application of autoclaving as a means of homogenizing neonatal pig carcasses was evaluated in two experiments. Aliquots of whole ground carcasses (n = 18) or split frozen carcasses (n = 6) were used as initial analytical material in exps. 1 and 2, respectively. No effect (P > 0.05) of autoclaving on the nitrogen, ash, petroleum ether extract or gross energy of the carcasses was detected. Chloroform:methanol (2:1) extractable material was increased in autoclaved samples (P < 0.0001), the increase attributable to additional protein and other nitrogenous material. The chloroform soluble fraction of the chloroform:methanol extract was increased by autoclaving (P < 0.01) while the petroleum ether soluble fraction was not changed (P > 0.05). Only small changes in fatty acid profile were detected (P < 0.05), but lipid subclass profile, as measured by an Iatroscan, was changed appreciably by autoclaving. Autoclaving was found to be a satisfactory, if not superior method to grinding for preparation of piglet carcasses for gross chemical analysis, provided the chloroform:methanol extract was further processed to identify true lipid content. Autoclaving may not be satisfactory for preparation of carcass samples for detailed lipid analysis. Key words: Proximate analysis, carcass composition, pig
ESTROGEN RECEPTOR CONTENT OF REGIONS OF THE HYPOTHALAMUS AND PITUITARY OF THE GILT FROM FOUR TO TWENTY-EIGHT WEEKS OF AGE
Authors: EVANS F. D. , CHRISTOPHERSON R. J. , AHERNE F. X.
Published: March 2010

Estradiol-17β receptors (E2R) in 100 000 × g supernatant fractions from the hypothalamus and pituitary were determined for groups of five gilts, slaughtered at 4-wk intervals from 4 to 28 wk of age. Tissue samples were separated into the anterior hypothalamus (AH), the central hypothalamus (CH), posterior hypothalamus (PH), anterior pituitary (AP) and posterior pituitary (PP). After saturation binding assays were conducted, E2R concentrations were determined by Scatchard analysis. When expressed on a fmol mg−1 protein basis there was no increase in receptor concentration with age (P > 0.05); however, AP had higher concentrations of receptors than the AH, CH or PH (10.6 ± 1.4 vs. 6.5 ± 0.9, 6.7 ± 0.7 and 6.2 ± 0.6, P < 0.01). Posterior pituitary receptor levels remained low during maturation of the gilt with affinity constant (Ka) values similar to that obtained for the AP. Affinity constant values were found not to change with age; however, AP values were greater than that of the hypothalamus samples (55.2 ± 2.7 vs. 4.8 ± 0.2, × 108M−1). On a total tissue basis AH and CH had significant increases in receptor content from 4 to 28 wk (41.4 to 138.2 and 31.6 to 163.4 fmol, P < 0.05). It was also determined that the soluble protein content per gram wet tissue decreased with age in all regions of the hypothalamus and therefore may mask increases in receptor numbers. Keywords: Estradiol, receptor, gilt, hypothalamus, pituitary, swine
SUBSTITUTION OF MILK PROTEIN WITH SOYFLOUR OR MEAT-SOLUBLES N CALF MILK REPLACERS
Authors: KHORASANI G. R. , SAUER W. C. , MAENHOUT F. , KENNELLY J. J.
Published: March 2010

Five Holstein male calves were fitted with ileo-cecal re-entrant cannulae. Calves were fed five milk replacers according to a 5 × 5 Latin square design. The control milk replacer (SM-100) was formulated so that 80% of the crude protein originated from skim milk powder and the remainder from whey proteins. In the test milk replacers, 40 or 60% of the skim milk protein was replaced by protein from soyflour (SF-40; SF-60) or meat-solubles (MS-40; MS-60). Diets were supplied at a rate of 50 g dry matter per unit metabolic body size (BWkg0.75) d−1. Average daily gain (ADG) and protein efficiency ratio (PER) decreased when SM was replaced by SF or MS. This depression was greater (P < 0.05) with higher levels of substitution and more marked for MS than SF. Plasma methionine concentration was lowest in calves fed the SF-60 and MS-60 diets. Average ileal digestibilities of the total of the indispensable amino acids were highest in SM-100 (94.6%), intermediate in MS-40 (88.0%) and MS-60 (86.8%) and lowest in SF-40 (83.8%) and SF-60 (82.1%). Fecal amino acid digestibilities did not differ between diets (P > 0.05). In summary, there was a decrease in ADG and PER when milk protein was replaced by protein from SF or MS. The inferior performance of calves fed SF- or MS-containing milk replacers is, in part, related to a lower digestible amino acid supply as measured in digesta collected from the distal ileum. Key words: Calf, milk replacers, soyflour, meat-solubles, amino acid digestibility
HIGH-ROUGHAGE RATIONS WITH OR WITHOUT MONENSIN FOR VEAL PRODUCTION. I. ANIMAL PERFORMANCE
Authors: POMAR C. , SEOANE J. R. , LATRILLE L. , BERNIER J. F.
Published: March 2010

Eighty-four calves 11–12 wk old (88 ± 10 kg BW) were used in a 47-d trial to study the effects of two ground roughages (alfalfa and timothy), their proportions in pelleted rations (20, 40 and 60%) and addition of monensin (0 and 33 ppm) on animal performance. After the trial, the animals continued to consume the rations until they reached a slaughter weight of 185 kg. Calves fed rations containing timothy showed higher dry matter (DM) and digestible energy (DE) intake and higher average daily gains (ADG) than calves fed rations containing alfalfa, which was partially due to the quality of the protein used to supplement the timothy rations. Proportion of roughage did not affect DM intake with the exception of 60% alfalfa rations which had the lowest intake. Increasing the roughage in the rations reduced DE intake and ADG, and increased feed conversion values (FC), particularly at 40 and 60%. Monensin increased DE intake and FC of rations containing 40 and 60% timothy, but had no effect on DM intake or ADG. Monensin increased DE conversion values when roughages were added at levels of 40 and 60%, the effect being greater with timothy. Dressing percentage of carcasses decreased with increasing levels of roughage in the ration, the lower values being obtained with timothy. Carcass classification and color of the meat were unaffected by the treatments. Key words: Alfalfa, timothy, roughage level, monensin, calf
CHANGES IN THE LIPID COMPOSITION OF THE INTERNAL ORGANS OF FETAL PIGS FROM SOWS FED DIFFERENT DIETARY FATS
Authors: FARNWORTH E. R. , KRAMER J. K. G.
Published: March 2010

Heart, liver, lungs and kidneys were taken from fetal pigs at 57, 85, and 110 d of gestation. Sows had been fed either a no-fat-added control diet or one with either added tallow (high in saturated fatty acids) or added soybean oil (high in unsaturated fatty acids). Maternal diet had no significant effect on organ weight, organ total lipid, or the percent composition of nine lipid classes in the total lipid extracts. Significant changes in composition were found as the fetuses developed, and differences in composition were also evident among tissues. The fatty acid composition of the triglyceride, phosphatidylcholine and phosphatidylethanolamine fractions of the four internal organs also showed developmental changes. Key words: Fetus, lipid, pig, organs, development
PROTECTION PROVIDED BY SODIUM SELENITE AGAINST AN ORAL TOXIC DOSE OF MONENSIN IN BROILER CHICKS
Authors: VANDERKOP PERRY A. , MacNEIL JAMES D.
Published: March 2010

Monensin is an ionophoric antibiotic that is widely used in cattle, swine and poultry production. In poultry it is used for its anticoccidial properties. Over the past decade several cases of flock poisoning due to monensin toxicity have been reported. Studies with cattle and swine demonstrate that Se-vitamin E pretreatment can provide a protective effect from an induced monensin toxicosis. In this study, 192 male broiler chicks were given one of eight diets, varying in the concentration of supplemented Se, as sodium selenite, from 0.5 to 15.0 mg kg−1, for a period of 4 wk. An oral dose of monensin sufficient to cause mortality, in the absence of a protective effect, was then given. It was observed that moderate levels of sodium selenite pretreatment did provide a protective effect from monensin toxicosis, expressed in terms of reduced morbidity and mortality. The concentrations needed to provide this protection, however, are above those recommended for dietary supplementation in broiler diets. For this reason more research on the interactions between monensin and Se and monensin and vitamin E needs to be conducted to find a means of protection from the potential threat of monensin toxicity in broiler flocks. Key words: Monensin, sodium selenite, broilers, toxicity
THE IMPORTANCE OF CLEAT SPACING IN RAMP DESIGN FOR YOUNG PIGS
Authors: PHILLIPS P. A. , THOMPSON B. K. , FRASER DAVID
Published: March 2010

Four ramp designs were tested for acceptance by pigs aged 7–8 wk and weighing about 16 kg. The designs included one ramp with a 22° slope and cleats spaced 100 mm apart, and three ramps with slopes of 28° and cleat spacing of either 100, 75 or 50 mm. Forty-eight litters were used in the study, each providing four pairs of pigs. Each of the four pairs was exposed to a different ramp design for 1 h, with ramp acceptance determined by whether a pig tried the ramp or not. Acceptance was much higher for the 22° ramp than the 28° ramp when the cleats were spaced at 100-mm (0.56 vs. 0.36, respectively; P < 0.01). However, there was a strong linear trend towards greater acceptance of the 28° ramp as cleat spacing was reduced (P < 0.001), so much so that acceptance of 50-mm spacing tended to surpass that of the 22° ramp with 100-mm spacing (0.70 vs. 0.56, respectively; P < 0.07). The results show that narrowly spaced cleats can compensate for steepness of slope in ramp designs for young pigs. Key words: Pigs, behavior, ramp design, cleat, spacing, slope
INFRARED THERMOGRAPHY OF PIGS WITH KNOWN GENOTYPES FOR STRESS SUSCEPTIBILITY IN RELATION TO PORK QUALITY
Authors: SCHAEFER A. L. , JONES S. D. M. , MURRAY A. C. , SATHER A. P. , TONG A. K. W.
Published: March 2010

Twenty five market-weight pigs averaging 92.0 kg body weight represented by eight halothane-negative with NN genotype, nine crossbred with Nn genotype and eight halothane-positive with nn genotype animals were thermographed to determine whether temperature differences were related to meat quality. Infrared thermograph analysis demonstrated no differences in mean external medial temperatures among genotypes in the live animal nor in the internal medial carcass surface. However, pigs with cooler mean side temperatures displayed a higher percent drip loss (P ≤ 0.09) and paler colored meat (P ≤ 0.03). This was particularly evident in the H+ pigs where a highly significant negative correlation between expressible juice (−0.87; P ≤ 0.01) as well as percent drip loss (−0.75; P ≤ 0.05) and mean live external medial surface temperature was observed. Furthermore, the halothane-positive pigs displayed small hot spots over the dorsal front shoulder area and over the posterior third of the animals. Key words: Infrared thermography, meat quality, pig genotype
MONENSIN, CHLORTETRACYCLINE AND TYLOSIN EFFECTS ON PERFORMANCE AND DIGESTION IN LAMBS FED A GROUND ALFALFA DIET
Authors: MIR Z.
Published: March 2010

Supplementing a control diet of ground alfalfa (CON) with monensin (MON), chlortetracycline (CTC) or tylosin (TYL) did not affect (P < 0.05) dry matter intake or average daily gain of market lambs. Feed efficiency with CTC was less than with the unsupplemented control (CON) (6.22 vs. 5.68) (P < 0.05). Mean digestibilities of dry matter, acid detergent fiber and neutral detergent fiber were lower (P < 0.05) with all antibiotic treatments than the CON diet. Relative to CON, nitrogen digestibility was increased with MON (66.3 vs. 70.9%) while that of energy was reduced with TYL (P < 0.05). Rumen ammonia and acetic, propionic and butyric acid concentrations were not influenced by any of the treatments. MON, CTC and TYL were not effective supplements for lambs fed alfalfa finishing diets. Key words: lamb, chlortetracycline, monensin, tylosin, alfalfa hay, digestibility
THE ALTERATION OF MILK CONTENT BY GENETIC ENGINEERING AND RECOMBINANT DNA-MEDIATED SELECTION TECHNIQUES
Authors: MUYSSON DAVID J. , GIBBINS ANN M. VERRINDER
Published: March 2010

Since the advent of gene cloning technology, suggestions have been made of specific alterations that could be engineered into the genomes of cattle, sheep or goats to alter their milk composition. These alterations could affect milk protein characteristics or quantity in ways which might be of benefit to milk processing and dairy product manufacturing industries. Other changes could improve the suitability of bovine milk for human consumption. In addition, animals could be engineered to synthesize valuable foreign proteins, such as pharmaceuticals, to be secreted in milk. In this paper, we evaluate these suggestions critically, taking into account current understanding of milk composition and processing, as well as recent information concerning the structure and regulation of genes coding for proteins involved in determining milk content. All these suggested alterations depend on successful production of transgenic animals capable of efficiently expressing introduced genes. The view is examined that some improvements in type or amount of certain milk proteins might better be achieved by conventional breeding practices, or by breeding systems that would rely on recombinant DNA techniques for methods of selection. Key words: Casein, beta-lactoglobulin, α-lactalbumin, plasmin, transgenic, bovine, ovine, lactose
REDUCED RATE OF ADIPOSE TISSUE GROWTH AND LIPID ACCUMULATION IN MICE SELECTED FOR HIGH BODY WEIGHT
Authors: SALMON R. KEITH , BERG ROY T.
Published: March 2010

To elucidate the influence of high body weight selection on tissue growth patterns, adipose tissue growth and lipid accumulation were investigated in both a line of mice selected for high 42-day body weight (High line; HL-3) and an unselected (Foundation; FP-3) population. All comparisons between the two lines were performed on a within-sex basis. Logistic growth curve analysis revealed that HL-3 mice exhibited an accelerated growth rate, and reached a higher mature body weight, than FP-3 mice. Employing the allometric equation, Y = aXb, this investigation further revealed that, relative to both body weight and nonadipose tissue weight, adipose tissue and extractable lipid increased slower in HL-3 mice than in FP-3 mice. Only at fixed body and nonadipose tissue weights, which exceeded the maximum weights achieved by the FP-3, did HL-3 adipose tissue and lipid weights exceed those of FP-3 mice. HL-3 mice have previously been demonstrated to exhibit an increased appetite. Therefore, the existing model of selection-mediated compositional changes should be expanded to allow the coupling of an increased appetite with an enhanced relative rate of nonfat tissue growth. Key words: Growth-selected mice, adipose tissue growth, lipid accumulation
POSTWEANING GAIN AND FEED EFFICIENCY OF CROSSBRED BULLS, STEERS AND HEIFERS FROM CHAROLAIS, SIMMENTAL AND LIMOUSIN SIRES MATED TO HEREFORD, ANGUS AND SHORTHORN DAMS
Authors: FREDEEN H. T. , NEWMAN J. A. , TONG A. K. W. , RAHNEFELD G. W.
Published: March 2010

Postweaning gain and feed efficiency results are reported from an evaluation of crossbred calves sired by Charolais, Simmental and Limousin bulls and born to Hereford, Angus and Shorthorn cows in 48 herds located throughout the Canadian Prairie Provinces. Bull, steer and heifer calves were weaned at approximately 7 mo of age and transported to the Brandon or the Lacombe Research Stations where their performance was measured during a 112-d postweaning test period in which male calves were fed a high-energy feedlot diet and heifers were developed as breeding females on a lower energy diet. The data, which did not represent all sire breeds or sexes in all station years, were analyzed in eight separate data sets for gain and five for feed efficiency. Interpretation is based on paired comparisons of breed crosses within data set. In general, Limousin-sired male calves gained an average of 14.0 kg less than Charolais-sired and 9.6 kg less than Simmental-sired male calves from comparable dams, while Charolais-sired and Simmental-sired male calves performed equally. The same breed-of-sire pattern was apparent in heifer calves fed a lower energy diet, but the effects were smaller and were significant less often. Breed-of-dam effects were apparent for on-test weight, but not for gain during the test period. There were no consistent breed-of-sire differences in feed conversion ratio. The cost to the feeder of the slower gain exhibited by the Limousin-sired calves in this experiment could be offset by the lower calf purchase weight, depending on the premium, if any, paid on the price per kg for the lighter calves. Key words: Beef cattle, breed comparison, post-weaning growth, feed efficiency
SELECTION OF SIRES ORIGINATING FROM A NUCLEUS BREEDING UNIT FOR USE IN A COMMERCIAL DAIRY POPULATION
Authors: TEEPKER GEORG , KELLER DAVID S.
Published: March 2010

Bulls that originate from breeding schemes with extensive use of multiple ovulation and embryo transfer (MOET) can be selected on pedigree information, the performance of their contemporary female full- and half-sibs or based on a progeny test. Combined selection across groups of bulls with different sources of information is shown to be superior to selection of progeny tested bulls alone. The magnitude of the superiority for a given selection rate is determined by the differences in genetic merit between the groups and ranges from 5 to 65%. Depending on the annual genetic progress the majority of the bulls are selected either on pedigree or progeny information. The proportion of sib-tested bulls ranges from 9 to 23%. When breeding activities are concentrated in nucleus herds, possible genotype by environment interactions between performance in the test herd and in the commercial population have to be considered. Genotype by environment interactions increase the proportion of progeny tested sires that will be selected. However, the proportion of progeny tested sires used is reduced by genotype by environment interactions among the groups of a heterogenous commercial production environment. Key words: Embryo transfer, sire selection, genotype-by-environment interactions
A METHOD FOR SEPARATING BIMODAL LENGTH FREQUENCY DISTRIBUTIONS IN JUVENILE ATLANTIC SALMON POPULATIONS
Authors: McMILLAN I. , BAILEY J. K. , FRIARS G. W. , QUINTON M. , HANKE A. R.
Published: March 2010

Growth studies on fish populations are often complicated by the presence of bimodality in the data. Traditional parametric tests are not applicable in these circumstances and familiar statistics such as mean and variance become difficult to interpret. Recent developments in catastrophe theory allow a new approach to working with multimodal distributions which provides specific parameters that have particular biological meaning. This paper presents an application of the nonmixture multimodal probability density function to length frequency distribution data collected on juvenile Atlantic salmon at the Atlantic Salmon Federation hatchery in St. Andrews, New Brunswick during the fall of 1982. The model was found to be a useful tool for describing the bimodal distributions and provided a set of parameters that can serve as a basis by which different population distributions can be compared. Key words: Fish breeding, bimodal distributions
POSTWEANING GROWTH RATE AND FEED CONVERSION RATIO OF LAMBS FED DIETS BASED ON CONCENTRATE VERSUS ROUGHAGES
Authors: FAHMY M. H. , FLIPOT P. M. , WOLYNETZ M. S. , COMEAU J. E.
Published: March 2010

Sets of twin lambs from both sexes representing 11 genetic groups were fed either concentrate (HE) or roughage (LE) diets from weaning to 32 kg liveweight. One lamb from each set received the HE diet while the other received the LE diet. Data on average daily gain (ADG), relative ADG (RADG) and feed conversion ratio (FCR) were analyzed to test for the presence of a genotype × diet interaction; this effect was significant for RADG. Although the ranking of the genetic groups with respect to RADG depended upon diet, the group ranking highest on HE was also the highest on LE. The set of twins × diet interaction was not significant for ADG or RADG. The results support the present practice in test stations of feeding lambs concentrate rations to identify their potential for growth and basing growth comparisons on a within genetic group basis. Key words: Genotype × diet interaction, growth rate, feed conversion ratio
EFFECT OF HYPOPHYSECTOMY ON BODY AND ORGAN WEIGHTS AND SUBSEQUENT DEVELOPMENT IN THE FETAL PIG
Authors: RANDALL G. C. B.
Published: March 2010

The effect of hypophysectomy on fetal growth and development was studied in 45 fetuses in which the pituitary had been destroyed by electrocoagulation between 68 and 84 d of gestation, and in 35 control littermates. Hypophysectomized fetuses were significantly heavier than their intact litter mates (1203 g vs. 1057 g; P < 0.05), were more edematous and had visible body fat stores. Fetuses hypophysectomized before 70 d of gestation were hairless and myxedematous, whereas in those hypophysectomized after day 80 the body surface either was similar to that of intact litter mates or had mild hypotrichosis. Hypophysectomy resulted in significant reductions in the weights of adrenal and thyroid glands and the testes, but did not influence fetal ovarian weight. In fetuses hypophysectomized after 80 d of gestation, no alteration of thyroid weight was noted. The spleen and kidneys were significantly heavier in hypophysectomized fetuses, whereas liver and heart weights were lighter. It is concluded that fetal hypophysectomy may increase fetal growth in the pig, and selectively alters the growth and maturation of individual organs. Key words: Hypophysectomy, body weight, organ weight, fetus
EFFECTS OF FEEDING SODIUM BICARBONATE TO PREPARTUM DAIRY COWS ON THEIR PERFORMANCE IN EARLY LACTATION
Authors: ST. LAURENT A-M. , BLOCK ELLIOT
Published: March 2010

Forty cows of second or greater parity were selected and blocked into 20 groups of two and randomly assigned to one of two prepartum diets; control prepartum (CP) or buffer prepartum (BP). The prepartum ration consisted of 85% grass hay, 10% ground corn and 5% dry cow supplement (dry basis). Sodium bicarbonate (NaHCO3) was fed at 0.6% of the total dry matter (DM) in the BP group. The postpartum ration was formulated to meet requirements for high-producing dairy cows in early lactation. Dry cows were placed on prepartum treatments 3 wk prior to expected calving date and abruptly switched to the postpartum ration on day 4 after parturition. For the first 4 wk of lactation the average daily total and concentrate DM intake as a percentage of body weight (BW) for cows fed rations BP and CP were not different. Forage intake as a percentage of BW and average production of 4% fat-corrected milk (FCM) was greater for CP than for BP. Milk fat test for CP and BP was not different. No differences were observed between CP and BP for rumen fluid parameters measured on days 14, 7 and 3 ± 2 prepartum. Total VFA (mg dL−1) and ratio of acetate-to-propionate was greater for CP than for BP; butyrate as a percentage of total VFA was greater for BP than for CP. Compared to controls, cows fed NaHCO3 prepartum did not perform as well during the first 4 wk postpartum as indicated by their lower forage intake and 4% FCM production. Key words: Sodium bicarbonate, cows (dairy), prepartum, performance
REDUCTION OF β-CONGLYCININ ANTIGENICITY AND RATE OF ACID-PEPSIN PROTEOLYSIS OF PROTEINS IN EXTRUDED OR RUMEN FLUID-TREATED SOYBEAN MEAL
Authors: MIR P. S. , BURTON J. H. , WILKIE B. N. , VOORT F. R. VAN DE
Published: March 2010

The effect of processing commercial soybean meal (HSBM) by either extrusion (ExSBM) or fermentation with microbes in rumen fluid (FSBM) on rate of protein hydrolysis and the activity of the antigen β-conglycinin was evaluated. Ethanol-extracted soybean meal (EtSBM) and skim milk powder (SMP) were included as positive controls while HSBM was the negative control, with regard to antigen content. The rates of proteolysis were determined by acid pepsin hydrolysis and the activity of β-conglycinin in the soluble fraction of the digestion mixtures at 0, 2, 4, 6 and 8 h of in vitro proteolysis was determined by radial immunodiffusion in agar gel containing antibody specific for the antigen. Susceptibility of FSBM and ExSBM to proteolysis by pepsin was greater than that of EtSBM. β-Conglycinin content was greatest in HSBM (1.0 ± 0.2 g dL−1) and only 0.3 ± 0.03 g dL−1 in ExSBM at the beginning of in vitro digestion. The antigen was not detected in either FSBM or EtSBM, therefore these products could be used in milk replacers for calves. Key words: In vitro pepsin proteolysis, extruded soybean meal, fermented soybean meal, antigen, β-conglycinin
EFFECT OF PLANT GROWTH REGULATORS AND HARVEST DATE ON YIELD, BOTANICAL COMPOSITION, CHEMICAL CONSTITUTION, INTAKE AND DIGESTIBILITY OF CRESTED WHEATGRASS-ALFALFA HERBAGE BY SHEEP
Authors: McCAUGHEY W. P. , COHEN R. D. H.
Published: March 2010

The effects of the plant growth regulators mefluidide (M) and maleic hydrazide (MH) were compared to untreated controls (C) at each of two harvest dates in 1987 (14 Aug. and 14 Sept.) and 1988 (27 June and 25 July). Plant growth regulators (PGR) were applied at rates of 0.28 kg active ingredient (a.i.) Mha−1 and 1.12 kg a.i. MH ha−1on 14 and 15 July 1987 and on 11 May 1988 to a mixed crested wheatgrass-alfalfa pasture. Application of PGR to the pasture reduced yield (P < 0.01) and increased (P < 0.05) the proportion of alfalfa in the mixture in 1987 only. Chemical composition of crested wheatgrass subsamples was largely unaltered by PGR treatment in 1987 but in 1988 crude protein (P < 0.01), in vitro organic matter disgestibility (P < 0.05) and ash (P < 0.001) were increased and neutral detergent fiber was decreased (P < 0.01). In 1987 the crude protein (P < 0.01) and ash (P < 0.05) contents of alfalfa were increased but were unaffected by PGR treatment in 1988. There were large differences in nutritional value between early- and late-harvest dates in 1987 when moisture was available but only small differences during the drought of 1988. In vivo digestibility of hay from treated plots in 1987 had lower organic matter digestibility (P < 0.001), hemicellulose digestibility (P < 0.001), cellulose digestibility (P < 0.05), acid detergent fiber digestibility (P < 0.05) and neutral detergent fiber digestibility (P < 0.01). In 1987, late-harvested material had lower digestible organic matter intake kg−0.75 and digestibilities of dry matter, organic matter, crude protein, hemicellulose, cellulose, acid detergent fiber, neutral detergent fiber and ash were significantly (P < 0.01) lower than for material harvested earlier. The improvements in forage quality were not sufficient to offset the large yield reductions which are likely to occur in a semi-arid environment. Key words: Plant growth regulators, mefluidide, maleic hydrazide, forage quality, sheep, intake
THE EFFECT OF GRADED LEVELS OF NICARBAZIN ON REPRODUCTIVE PERFORMANCE OF LAYING HENS
Authors: LEESON S. , CASTON L. J. , SUMMERS J. D.
Published: March 2010

Three experiments were undertaken to investigate the coccidiostat, nicarbazin, on reproductive performance of layers. In trial 1, levels of 0, 5, 10, 20, 40, 80, 125, and 200 ppm nicarbazin were fed to White leghorn laying hens for 5 wk. By the 2nd week of nicarbazin treatment, egg production was significantly reduced in birds fed 125 and 200 ppm (P < 0.05). Similarly, increasing levels of nicarbazin resulted in decreasing egg weights (P < 0.01) and feed intake was significantly decreased. However, by the 2nd week post-nicarbazin treatment, egg production, egg weight, and feed intake had returned to normal. Nicarbazin had no effect on egg shell deformation or body weight. Nicarbazin had a marked effect on hatchability; levels of 125 and 200 ppm reduced hatchability significantly (P < 0.01) as well as producing an increased incidence of malpositions and malformations. When nicarbazin was withdrawn from the diet, hatchability returned to pretreatment values although malpositions and malformations were still in evidence. Experiments 2 and 3 were designed to study the effect of nicarbazin on production of brown-shelled eggs. In the 2nd experiment 0, 5, 10, 20, and 40 ppm of dietary nicarbazin resulted in significant loss of shell color at 20 and 40 ppm, whereas in exp. 3 with levels of 0, 80, 125, and 200 ppm, brown eggs lost virtually all their color. It is concluded that the adult White Leghorn bird can tolerate up to 125 ppm nicarbazin without significant (P < 0.01) loss of reproductive performance although lower levels show a trend for reduced production. Hatchability is depressed with nicarbazin levels in excess of 80 ppm, while trace levels will produce a visual loss of color in brown-shelled eggs. Key words: Layer, coccidiostat, reproductive performance
FEED TEXTURE EFFECTS ON THE PERFORMANCE OF ROASTER CHICKENS
Authors: PROUDFOOT F. G. , HULAN H. W.
Published: March 2010

Two experiments were conducted, each experiment involved 1600 day-old Arbor Acre male broiler chickens which were assigned to 20 pens divided into four blocks of five pens each with five feed texture treatments assigned to the pens within each block. The five treatments were (1) All mash — corn and wheat finely ground, (2) All mash — corn and wheat coarsely ground, (3) All mash — corn and wheat very coarsely rolled, (4) same as no. 1 but crumbled or pelleted and (5) same as no. 2 but crumbled or pelleted. Although feed texture had no overall significant (P > 0.05) effect on mortality, mortality was higher among birds fed the crumble-pellet diets compared with those fed the all-mash diets, this higher mortality was due to a higher incidence of Sudden Death Syndrome. Finely and very coarsely ground diets fed as mash resulted in significantly poorer feed conversion at both 21 d (P < 0.001) and 49 d of age (P < 0.01); however, there was no significant (P < 0.05) effect of feed texture on feed conversion at 63 d of age. Body weights were significantly (P < 0.01 to P < 0.001) affected by feed texture at 21, 49 and 63 d of age with the feeding of finely ground mash resulting in the lowest body weights with the heaviest final body weights exhibited by birds fed diets which were either fine or coarse ground mashes which had gone through the crumble and/or pellet process. Feed texture dietary treatments had no effect on the incidence of leg abnormalities. Monetary returns per bird started were significantly (P < 0.05) depressed by the feeding of finely ground mash to chickens while other feed texture treatments were not significantly (P > 0.05) different. Key words: Chicken (roaster), feed texture, ingredient particle size