bluuebunny/crossref_metadata_2025 huggingface dataset:
NEUTRAL AMINO ACID TRANSPORT IN SHEEP EXTERNAL INTERCOSTAL MUSCLE
Authors: FORSBERG NEIL E. , KANEPS ANDRIS J. , RIEBOLD THOMAS W.
Published: March 2010

The transport of two amino acid anologs, aminoisobutyric acid (AIB) and N-methylaminoisobutyric acid (MeAIB), was studied in external intercostal muscle bundles taken from 12 wether lambs to examine the significance of these transport systems in sheep muscle tissue. Competition for transport between AIB and other amino acids was evaluated to determine proportions of AIB transported on individual carriers. Rates of AIB transport into EIC muscle in relation to previous liveweight gains of lambs and animal weights were also examined. Aminoisobutyric acid was concentrated to approximately fourfold extracellular AIB concentrations via a sodium gradient-dependent process within 2 h of incubation. However, MeAIB was not concentrated by this tissue. Kinetic analyses of MeAIB transport indicated that its entry was entirely nonsaturable. Since MeAIB is a model substrate for transport system A (Na gradient-dependent, hormone and substrate concentration regulated) and since AIB may be transported by both systems A and ASC (Na gradient-dependent, hormone and substrate concentration insensitive), the active transport of AIB is attributed primarily to a system ASC-like agency. Kinetic analyses of the Na gradient-dependent transport of AIB revealed Jmax and Kt values of 2.48 ± 0.35 μmoles g tissue−1 30 min−1 and 11.4 ± 4.2 mM, respectively. Competition studies between AIB and other analogs provided further support for the existence of an ASC-like transport agency and the possible absence of or a repressed system A. A significant relationship between previous liveweight gain and amino acid transport was not detected; however, AIB transport in muscle taken from more mature animals was significantly lower than in muscle taken from younger animals. Key words: Sheep, muscle, amino acid transport, system A, system ASC
INFLUENCE OF LASALOCID ON THE PRODUCTION OF GESTATING EWES IN AN EXTENSIVE GRAZING SYSTEM
Authors: THOMAS V. M. , AYERS E. , HANFORD K. , KOTT R.
Published: March 2010

A winter feeding trial was conducted to evaluate the influence of lasalocid (L) on the production of gestating ewes in an extensive grazing system. Six hundred and sixty ewes were randomized within age and breed and allotted to feed supplements (0.23 kg head−1 d−1) containing either no L (C) or L at 308 mg kg−1 and fed for 84 d during gestation. Ewe weight change within periods (three, 28-d periods) was similar (P > 0.10) with the exception of period 2 where L-supplemented ewes tended to gain more (P < 0.10) weight than C ewes. Total ewe weight change during the wintering period and yearly wool production were not affected (P > 0.10) by treatment. Treatment had no affect (P > 0.10) on the percentage or kilograms of lamb weaned for ewes starting the experiment. Ewes suckling twins and fed L during gestation had less (P < 0.05) lambs bummed (lamb removed from the ewe and sold) or grafted (lamb removal from the ewe and raised by a foster mother) than those in C group and suckling twins. In conclusion, providing L in a supplement to gestating ewes grazing winter range did not significantly alter production with the exception of less twin born lambs being bummed or grafted. Key words: Sheep, lasalocid, gestation, winter range, ewe, lamb
IMPROVEMENT IN NUTRIENT RETENTION AND CHANGES IN EXCRETA VISCOSITIES IN CHICKS FED RYE-CONTAINING DIETS SUPPLEMENTED WITH FUNGAL ENZYMES, SODIUM TAUROCHOLATE AND PENICILLIN
Authors: FENGLER A. I. , PAWLIK J. R. , MARQUARDT R. R.
Published: March 2010

Three feeding experiments were performed with chicks to study the effects of supplementing sodium taurocholate, penicillin and a crude fungal enzyme preparation, Trichoderma viride cellulase (T.v. cellulase), in rye- and wheat-based diets on the viscosity of water extracts of feed and excreta and on nutrient retention. Sodium taurocholate had no effect (P > 0.05) on the viscosity of extracts of the diet or excreta but slightly improved fat retention (P < 0.05) in chicks fed a rye-containing diet. Penicillin treatment had no direct effect on the viscous component in rye, but increased (P < 0.05) fecal viscosity and fat retention in chicks fed rye-containing diets. T.v. cellulase produced the most dramatic results among the treatments increasing (P < 0.05) fat and dry matter retention by 12 and 5 percentage units, respectively, in the rye-fed birds, but had no effect (P > 0.05) on these parameters when added to a wheat-based diet. Also, T.v. cellulase dramatically reduced excreta viscosity which was different to the effect of sodium taurocholate and opposite to the effect obtained with penicillin. An in vitro study also tested five crude enzyme preparations of widely diverse origin. T.v. cellulase was by far the most efficient viscosity-reducing enzyme and as a result was selected for the animal studies. In conclusion, penicillin, crude fungal enzyme, and sodium taurocholate additions to a rye-based diet increased, decreased or had no effect on excreta viscosities, respectively, but in all cases increased fat retention. They therefore probably have different mechanisms of action. Key words: Chicks, rye diet, nutrient retention, excreta viscosity, fungal enzyme, penicillin, sodium taurocholate.
OMEGA-3 FATTY ACID LEVELS AND PERFORMANCE OF BROILER CHICKENS FED REDFISH MEAL OR REDFISH OIL
Authors: HULAN H. W. , PROUDFOOT F. G. , ACKMAN R. G. , RATNAYAKE W. M. N.
Published: March 2010

Arbor Acre broiler chickens were fed six different diets to determine if the omega-3 fatty acid content of broiler chicken carcasses could be enhanced by feeding additional redfish meal (RFM) or redfish oil (RFO). The six diets were: control (no fish meal or fish oil); 7.5% RFM, 15.0% RFM, 30.0% RFM, 2.1% RFO and 4.2% RFO. Mortality at 28 d and 42 d was lower (P < 0.05) for birds fed RFO compared to those fed RFM. Feeding additional RFM or RFO had no (P > 0.05) effect on mortality, but resulted in lower body weights (P < 0.01) and feed consumption (P < 0.05) and poorer (P < 0.05) feed conversion. Additions of RFM or RFO to the diets resulted in a substantial dietary enrichment of omega-3 fatty acids (especially eicosapentaenoic acid, EPA or 20:5n-3; and docosahexaenoic acid, DHA or 22:6n-3). Analyses (wt/wt %) revealed that breast meat was lower (P < 0.001) in lipid and triglyceride but higher in cholesterol esters (P < 0.005), free cholesterol (P < 0.001) and phospholipid (P < 0.001) than thigh meat. Lipid, free cholesterol and phospholipid of edible meat lipid increased with duration of feeding (14 d, 28 d, 42 d) but triglyceride content decreased. Dietary treatment had no effect (P > 0.05) on carcass lipid content or composition. Breast meat lipid contained more (P < 0.001) of the omega-3 fatty acids (especially EPA and DHA), more n-3 docosapentaenoic acid (DPA or 22:5n-3) and more total n-3 polyunsaturated fatty acid (n-3 PUFA) than thigh meat lipids. EPA, DPA, DHA and total n-3 PUFA in edible meat lipids increased (P < 0.05) with duration of feeding. Feeding additional RFM and RFO resulted in an increased accumulation of the EPA (P < 0.001), DPA (P < 0.01), DHA (P < 0.01) and total n-3 PUFA (P < 0.001), primarily at the expense of the omega-6 fatty acids linoleic (18:2n-6) and arachidonic (20:4n-6). It can be calculated from the data presented that on average a normal meal (100 g) of chicken which has been fed 7.5% fish meal, would contribute 140 mg of omega-3 fatty acids (EPA + DPA + DHA). The same size meal of cod flesh would contribute about 135 mg of these fatty acids. Key words: Broiler chickens, breast, thigh, redfish meal, eicosapentaenoic acid, omega-3 fatty acids
THE RELATIONSHIP OF SIRE EVALUATIONS FOR EASE OF CALVING AND BIRTH WEIGHT
Authors: TONG A. K. W. , NEWMAN J. A. , RAHNEFELD G. W. , LAWSON J. E.
Published: March 2010

Best Linear Unbiased Prediction procedures were used to evaluate 204 Beefmaster, Charolais, Simmental, Limousin, Red Angus and Chianina sires for birth weight (BW) and ease of calving (EC) based on the performance of a total of 6758 progeny. Correlations between BW and EC for sire means ranged from −0.77 to 0.08 with an average of −0.27 and for sire proofs they ranged from −0.90 to 0.14 with an average of −0.41. These results suggest that there is a strong relationship between the traits and that BW may be a valuable trait for use in indirect selection to reduce calving problems. Key words: Beef, ease of calving, birth weight, sire evaluation, correlation of sire proofs
GENOTYPE × ENVIRONMENT INTERACTIONS FOR BEEF COW PERFORMANCE DURING LACTATION
Authors: FREDEEN H. T. , WEISS G. M. , RAHNEFELD G. W. , LAWSON J. E. , NEWMAN J. A.
Published: March 2010

Genotype × environment interactions for beef cow performance traits expressed during lactation were evaluated for 10 F1 cow crosses. The crosses (genotypes) were represented by the Hereford-Angus (HA) and nine crosses produced by mating Charolais (C), Simmental (S), and Limousin (L) sires with cows of Hereford (H), Angus (A) and Shorthorn (N) breeding. Environmental differences were provided by two climatically distinct locations (Brandon, Manitoba; Manyberries, Alberta) with two treatments (drylot confinement vs. pasture) imposed at each location in each of 3 consecutive years. The total data set comprised 1274 cow-calf pairs with milk production data recorded for 730 lactations. Substantial (P < 0.01) year, treatment and breed cross effects were present at each location for virtually all of the traits evaluated (cow weights and average subcutaneous fat, weight and fat changes during lactation, milk yield, calf growth rate, conception rates). Substantial (P < 0.0001) year × treatment interactions were also present. No genotype × environment interactions (year × breed cross, breed cross × treatment) were identified at either location for preweaning growth rate of calves, average daily milk yield of the cows or date of conception. Location differences were large for all of these traits, but rankings of the breed crosses at the two locations were in close agreement, indicating the absence of any location × genotype interactions. The ranking of breed crosses for conception rate was unaffected by treatment or year within each location, but the rankings did differ between locations. Under the environment provided at Manyberries conception rates tended to be inversely related to average milk yield of breed crosses, while no such relationship was evident under die conditions at Brandon. Key words: Genotype × environment interaction, beef cattle, cow productivity, calf performance
EVALUATION OF DAIRY CATTLE FOR FINAL CLASS USING ANIMAL MODELS
Authors: JAMROZIK J. , SCHAEFFER L. R.
Published: March 2010

Estimated breeding values for final class of 364 868 Canadian Holstein Friesian cows and 10 186 bulls from three different animal models were compared. FIRST lactation, first classifications were described by a model with fixed effects of herd-round-classifier, linear and quadratic effects of age at calving and stage of lactation at classification, and random effects of additive genetic effects of cows, and residual effects. All additive genetic relationships among animals were included. A second model used the LATEST classification on each cow rather than the first and these observations were pre-adjusted for age and stage. The third model used ALL classifications on each cow, and these were also pre-adjusted for age and stage effects. Correlations among estimated breeding values between methods ranged from 0.92 to 0.95. Estimated breeding values from LATEST were most highly correlated to sire proofs from the currently official sire model which also used the latest classification of each cow. Correlations of estimated breeding values between sires and their sons showed that results from LATEST were more accurate than results from the other two models. A model similar to that for LATEST is proposed for official genetic evaluations for conformation in the Canadian Holstein population. Key words: Animal model, conformation, dairy cattle
FAILURE OF EXOGENOUS PROSTAGLANDIN F2α TO ENHANCE UTERINE INVOLUTION IN BEEF COWS
Authors: GUILBAULT L. A. , VILLENEUVE P. , DUFOUR J. J.
Published: March 2010

Twenty-four beef cows of 5th parity were fitted with catheters in the descending aorta via a superficial costoabdominal artery. On the day of parturition (day 0), cows were assigned randomly and equally to two infusion treatments and three slaughter groups. Cows were infused continuously for 11 d with either prostaglandin F2α-tham salt (PGF2α; 33.5 mg d−1 from days 2 to 13) or 0.9% physiological saline (saline) via the descending aorta. In the first slaughter group, cows were suckled until slaughtered on day 15. Cows in the second slaughter group were suckled until slaughtered on day 35; whereas in the third group, calves were weaned on day 31 and cows slaughtered on day 35. Reproductive tracts were collected at slaughter and degree of uterine involution was assessed by recording weight and diameter of the cervix, weight, diameter and length of both uterine horns as well as surface areas of caruncular and intercaruncular endometrium. During the infusion period, plasma concentrations of 15-keto-13, 14-dihydro-PGF2α, the primary metabolite of PGF2α, were higher in PGF2α- than in saline-infused cows (1091 vs 738 pg mL−1, SE = 105, P < 0.03). All cervical and uterine (except uterine horn diameter) measures of involution were greater (P < 0.1) on day 15 than on day 35. Calf removal did not affect (P > 0.1) uterine involution on day 35. None of the responses measured to assess uterine involution differed (P > 0.1) between PGF2α- and saline-infused cows on day 15 or 35. It is concluded that early postpartum administration of PGF2α by continuous infusion does not alter uterine involution in terms of reduction in size and tissue loss by days 15 and 35 postpartum. Key words: Cows, postpartum, prostaglandin F2α, uterine involution.
PHENYLALANINE METABOLISM IN SHEEP INFUSED WITH GLUCOSE PLUS INSULIN. I. EFFECTS ON PLASMA PHENYLALANINE CONCENTRATION, ENTRY RATE AND UTILIZATION BY THE HINDLIMB
Authors: EARLY RICHARD J. , McBRIDE BRIAN W. , BALL RONALD O.
Published: March 2010

Experiments were conducted with chronically catheterized sheep to study the relationships between plasma phenylalanine concentration, entry rate (determined with 3H-phenylalanine), and utilization by the hindlimb during infusions of either saline (S) or glucose plus insulin (G+I). Infusions of G+I approximately doubled (P < 0.10) plasma insulin concentrations but maintained glucose concentrations similar to S-infused animals. Phenylalanine concentrations and entry rates decreased (P < 0.10) with G+I infusions. Phenylalanine arteriovenous differences and net plasma exchange across the hindlimb (arteriovenous differences multiplied by plasma flow) were not affected by treatments. However, the rates of plasma 3H-phenylalanine removed by the hindlimb were greater (P < 0.10) in G+I (17 μmol h−1 kg0.75) than S (9 μmol h−1 kg0.75) treated animals. These rates of hindlimb removal accounted for 26 and 10% of the phenylalanine entry rate, respectively. These data indicate that although G+I infusions decreased plasma phenylalanine concentrations and entry rates, a greater proportion of the entry rate was utilized by the hindlimb in G+I than in S sheep. Key words: Sheep, phenylalanine, entry rate, hindlimb, insulin, glucose
PHENYLALANINE METABOLISM IN SHEEP INFUSED WITH GLUCOSE PLUS INSULIN. II. EFFECTS ON IN VIVO AND IN VITRO PROTEIN SYNTHESIS AND RELATED ENERGY EXPENDITURES
Authors: EARLY RICHARD J. , McBRIDE BRIAN W. , BALL RONALD O.
Published: March 2010

In vivo fractional rates of protein synthesis (FSR), based on both intracellular fluid (ICF) and arterial plasma specific radioactivity (SRA), were determined for the external intercostal muscle (EIC), gastrocnemius muscle, liver and kidneys of growing sheep during infusions of either saline or glucose (2 g h−1) plus insulin (1.2 U h−1; G+I). In vitro FSR and energy expenditures associated with protein synthesis (cycloheximide-sensitive respiration) and Na+, K+ transport (ouabain-sensitive respiration) were also determined in EIC muscle. In vivo FSR based on ICF SRA in muscle were not significantly different between G+I and S infused sheep (5.2 vs. 4.2% d−1 and 5.0 vs. 3.2% d−1 for EIC and gastrocnemius, respectively). In vivo FSR in the liver (54 vs. 61% d−1) and kidneys (38 vs. 55% d−1) were also not significantly different between G+I versus S infused sheep. Based on plasma SRA, FSR in all tissues were unaffected by treatments and were less (P < 0.05) than those calculated from ICF SRA. In vitro FSR and the energy expenditures associated with protein synthesis and Na+, K+ transport were not affected by G+I infusions. The average in vitro FSR in isolated EIC muscle (2.7% d−1) was 53% and 81% of the average in vivo FSR calculated from ICF and plasma SRA, respectively. Compared to data reported for nonruminants, these data suggest that rates of protein synthesis and energy expenditures associated with protein synthesis in ruminants are less influenced by insulin and glucose. Key words: Sheep, protein synthesis, insulin, glucose, Na+, K+ transport
A COMPARISON OF CANOLA ACIDULATED FATTY ACIDS AND TALLOW AS SUPPLEMENTS TO A GROUND ALFALFA DIET FOR SHEEP
Authors: MIR Z.
Published: March 2010

Experiments were conducted to determine the effects of supplementing ground alfalfa diets with 0, 3, 4, 5 or 10% canola acidulated fatty acids (CAFA) or tallow on digestion in the rumen, and on nutrient digestibility and performance by sheep. Effects of these treatments on in situ dry matter (DMD) and nitrogen (ND) disappearance were measured by the nylon bag technique using rumen-fistulated cattle. DMD was reduced (P < 0.05) for diets containing CAFA at the 5 and 10% levels after 24 and 48 h of incubation in the rumen and for diets containing tallow at all levels after 48 h incubation. ND from the nylon bags was not affected by fat supplementation. A digestibility experiment with 36 mature wethers in a completely randomized design showed no differences (P > 0.05) in dry matter, nitrogen, acid detergent fiber or energy digestibility between unsupplemented and fat-supplemented diets. Neutral detergent fiber digestibility, however, was greater (P < 0.05) for the 3% CAFA, 4% tallow and 10% tallow diets than the control. Fat supplementation did not influence rumen fermentation characteristics such as pH and volatile fatty acid patterns. In a feeding trial with 84 weaned lambs in a completely randomized design, supplementation with 5% CAFA or tallow at 3, 4 and 5% resulted in increased liveweight gain when compared with control (P < 0.05). Average dry matter intakes were similar with all the fat supplemented diets. Key words: Sheep, tallow, canola acidulated fatty acids, alfalfa hay, digestibility
AMMONIA OR SULPHUR DIOXIDE TREATMENT OF HIGH-MOISTURE BARLEY ON IN SITU RUMEN DEGRADABILITY AND IN SITU WHOLE-TRACT DIGESTIBILITY
Authors: ROBINSON P. H. , KENNELLY J. J.
Published: March 2010

High-moisture barley (HMB) was ensiled in polyethylene silage bags. Treatments applied to 30% moisture HMB as a percentage of dry matter (DM) were: none, 1% ammonia, 2% ammonia, and 1.5% sulphur dioxide. A fifth treatment was the addition of 1.5% sulphur dioxide to 20% moisture HMB. Barley samples were ruminally incubated to estimate degradability of DM and nitrogen (N). Ruminally incubated bags were also introduced to the duodenal cannulae and collected in feces to estimate true whole-tract digestion. Sulphur dioxide treatment, or moisture content, had no influence on ruminal degradability, with the exception of increased degradation rate of potentially degradable N for 20 vs 30% HMB, or whole-tract true digestion. Ammoniation resulted in net reduction in rate of ruminal DM release due to shift of soluble DM to the potentially degradable fraction, and decrease in the potentially degradable fraction degradation rate. Ammoniation increased barley N content up to 44% with no change in rate of ruminal N release. Whole-tract true DM digestion was higher for ammoniated barley but N digestion was not influenced. Sulphur dioxide appears to offer no advantages beyond grain preservation, whereas ammoniation offers potential by reducting rate of ruminal DM release, and providing a source of slow release nonprotein N, without affecting post-ruminal digestibility. Key words: High-moisture barley, ammonia, sulphur dioxide
EFFECTS OF FAUNATION, PROTEIN SOURCE AND SURGICAL MODIFICATION OF THE INTESTINAL TRACT UPON FLOWS OF CALCIUM, PHOSPHORUS AND MAGNESIUM IN THE DIGESTIVE TRACT OF SHEEP
Authors: BOILA R. J. , PHILLIPS G. D.
Published: March 2010

Effects of faunation and protein source, corn gluten meal (CGM) versus soybean meal (SBM) upon Ca, P and Mg in the digestive tract of sheep were evaluated. Twelve yearling rams with cannulae in the abomasum and terminal ileum, and with sections of the small intestine bypassed (no bypass, n = 4; proximal third, n = 4; a distal third, n = 4) were used. All sheep were verified afaunated (protozoa-free) from birth; all sheep were faunated for the last half of the experiment. Negative Ca balances were obtained: for afaunated (P < 0.01) relative to faunated sheep, with less (P < 0.01) Ca absorbed in the stomach section and more (P < 0.01) Ca secreted in the large intestine of afaunated sheep; and for SBM (P = 0.07) as opposed to CGM fed sheep, with less (P < 0.01) Ca absorbed in the stomach section of SBM sheep. With SBM fed, afaunated sheep, the Ca balance was the same as that measured in all proximal bypass sheep. Proximal bypass surgery had a minimal effect (0.10 > P > 0.05), while protein source had no (P > 0.05) influence upon P or Mg. Faunation influenced P secretion (P < 0.05) and Mg absorption (P < 0.05) in the stomach section, and P absorption (P < 0.05) in the small intestine. More dietary P (P < 0.05) and Mg (P < 0.01) was absorbed from the digestive tract of faunated than afaunated sheep. Key words: Sheep, faunation, calcium, phosphorus, magnesium, digestion
RESPONSE OF MALE AND FEMALE BROILERS TO DIET PROTEIN
Authors: LEESON S. , CASTON L. J. , SUMMERS J. D.
Published: March 2010

Two experiments were conducted to note the broilers' response to graded levels of dietary protein (CP). Female birds were fed one of six diet series ranging from 22–20–18 to 18–18–16% CP from 0–21 days, 21–35 days and 35–42 days, respectively. Males were fed diet series from 28–24–22 to 20–18–16 over the same time periods (Table 1). Each diet program was tested with four replicate groups of 60 birds. Body weight and feed intake were monitored at time of feed change-over and at termination of experiment. Twenty birds per replicate were used for carcass analyses. Females were heavier when diets of higher protein content were offered (P < 0.05). These birds consumed more feed (P < 0.05) but exhibited feed efficiency that was not different to birds fed diets of lower protein content. Carcass weight and breast meat yield were not influenced by diet, although higher-protein diet series resulted in reduced proportional abdominal fat pad size (P < 0.01). Diet protein had no effect on body weight of male birds at 42 d (P > 0.05). Male birds reared on a program involving die lowest CP levels of 20–18–16 exhibited inferior feed utilization relative to birds from most other treatments (P < 0.05). Programs with low-protein diets for males resulted in reduced carcass weight, reduced breast meat yield and increased abdominal fat deposition (P < 0.05). It is concluded that male birds can be reared on very low protein diets without loss of weight, although carcass quality will be inferior. Female broilers are heavier when diet protein intake is increased through use of diets with higher protein content. Key words: Broiler, diet protein, performance, carcass composition
EFFECTS OF EXTRUSION COOKING OF BARLEY ON ILEAL AND FECAL DIGESTIBILITIES OF DIETARY COMPONENTS IN PIGS
Authors: FADEL JAMES G. , NEWMAN C. WALT , NEWMAN ROSEMARY K. , GRAHAM HADDEN
Published: March 2010

The effect of extrusion cooking on ileal and fecal digestibilities of dietary components in the pig was studied. Five crossbred ileal-cannulated pigs were fed a raw barley-based diet or an extruded barley-based diet in a crossover design. Klason lignin increased and starch decreased with extrusion cooking. Extrusion cooking also caused a shift of insoluble nonstarch polysaccharides (NSP) to soluble NSP. Ileal dry matter was lower and fecal dry matter higher from pigs fed the extruded diet compared to pigs fed the raw diet. Pigs fed the extruded diet had higher ileal digestibilities for dry matter, energy, starch and Klason lignin. No significant differences in fecal digestibilities were found, except for Klason lignin, when comparing pigs fed raw and extruded diets. Fecal digestibilities tended to be higher than ileal digestibilities for all dietary components for both diets except for crude fat, where there was no difference. Pigs fed the extruded diet had higher soluble NSP and lower insoluble NSP ileal digestibilities. Extrusion altered the chemical composition and dietary component digestibilities at the ileum but not at the feces. Increased energy utilization of the extruded diet in the upper tract occurred primarily because of an increased digestion of starch. Key words: Extrusion cooking, barley, digestibility, pigs
THE EFFECT OF THE ESSENTIAL TO NONESSENTIAL AMINO ACID RATIO ON TURKEY PERFORMANCE AND CARCASS COMPOSITION
Authors: BEDFORD M. R. , SUMMERS J. D.
Published: March 2010

The effect of altering the proportion of dietary protein supplied as essential amino acids (EAA) on the performance and carcass characteristics of young turkeys (to 3 wk of age) was investigated at three dietary protein levels (22, 26 and 30%) using semipurified diets. Four ratios of EAA to nonessential amino acids (NEAA) were employed (70:30, 60:40, 50:50 and 40:60) at each dietary protein level. Maxima in weight gain, percent and total carcass protein and feed intake were observed when EAA supplied 60% of total protein (i.e., the 60:40 ratio) at each protein level. The differences in weight gain and total carcass protein were largely attributed to differences in feed intake, since feed conversion efficiency was relatively unaffected by altering the EAA: NEAA ratio. More specifically, weight gain was shown to be limited by total protein intake. Since weight gain was maximized at the 60:40 ratio diets (in which all EAA are supplied at 128% of requirement) at least one of the EAA requirement values is incorrect. Key words: Turkeys, essential amino acids, protein requirement
APPARENT FEED PARTICLE SIZE PREFERENCE BY LAYING HENS
Authors: PORTELLA F. J. , CASTON L. J. , LEESON S.
Published: March 2010

Trials were designed to investigate the effect of feed particle size on apparent feed intake of laying hens. Feed was offered to five different groups of four birds each as either regular crumbles, mash, large crumbles (trained birds), large crumbles (untrained birds) or small crumbles, respectively. Except for the untrained birds, all birds were given a 15-d adaptation period. In each trial hens were offered 200 g of feed at 05:00 h and at each subsequent hour, until 20:00 h, feed was removed from the trough, sieved, weighed, remixed and returned to the feeders. Chemical analysis of the diet and various diet fractions was undertaken. There was marked disappearance of larger particles when birds were fed regular crumbles. However, smaller particles disappeared as the concentration of large ones decreased throughout the day. There was no marked disappearance of particles smaller than 0.60 mm. Feed intake was comparable when regular crumbles or mash rations were fed. Overall feed intake increased when small particles were offered, while intake decreased when the feed was changed abruptly to one of only large particles. It is concluded that particle size in regular crumbled layer feed is not uniform, and that particle size influences disappearance rate. Key words: Layer, particle preference, nutrient preference
EFFECT OF NUTRITIONAL FLUSHING, SUPPLEMENTAL FAT AND SUPPLEMENTAL LYSINE FROM PUBERTY TO BREEDING AND DURING EARLY GESTATION ON REPRODUCTIVE PERFORMANCE OF GILTS
Authors: GRANDHI R. R.
Published: March 2010

Four experiments were conducted, using a total of 356 Landrace × Yorkshire crossbred gilts, to determine the influence of flushing, supplemental fat and supplemental lysine fed from puberty to breeding (exps. 1 and 2) and from puberty through early gestation (exps. 3 and 4) on the reproductive performance of gilts. All gilts were housed in total confinement and fed ad libitum a 16% protein swine grower diet until 150 d of age. The diet was then restricted to 2 kg d−1 until puberty. The treatment diets fed from puberty to breeding in exps. 1 and 2 were: (1) control, a 12% protein barley-soybean meal gestation diet fed at 2 kg d−1 (24.4 MJ DE d−1); (2) flushing, control diet fed at 3 kg d−1 (36.6 MJ DE d−1; (3) animal fat, control diet fed at 2 kg d−1 plus 622 g of fat premix (36.6 MJ DE d−1; and (4) lysine, control diet with supplemental lysine (14 g d−1) fed at 2 kg d−1 (24.4 MJ DE d−1). After breeding, all gilts were fed control diet at 2 kg d−1 until approximately 30 d at gestation. In exps. 3 and 4, the same treatment diets were used except flushing was omitted and they were fed from puberty to approximately 30 d of gestation. No significant differences (P > 0.05) among the treatment groups were found in any of the experiments for the number of corpora lutea and normal embryos, and ovarian, uterine, and fetal weights. In exp. 2, the embryo survival rate (%) was significantly lower (P < 0.05) in the flushing (81.7 ± 3.3) and animal fat (78.3 ± 3.3) groups than in the control (92.9 ± 3.0); however, the lysine (88.8 ± 3.5) group did not differ significantly from the other groups. The embryo survival rate was also reduced (P < 0.05) by supplemental fat (81.5 ± 2.7) when compared to the control (86.8 ± 3.0) and lysine (88.8 ± 2.7) diets in exp. 3 but not in exp. 4. The serum progesterone level (ng/mL−1) was lower (P < 0.05) in the animal fat group (4.1 ± 0.6) than in the control (6.3 ± 0.6) and lysine (6.1 ± 0.6) groups in exp. 4. However, progesterone level of allantoic fluid in exp. 4 and estrone sulfate levels of both serum and allantoic fluid in exps. 3 and 4 were similar for the three treatment groups. The overall results indicated that flushing, supplemental fat or supplemental lysine fed from puberty to breeding, and supplemental fat or supplemental lysine fed from puberty through early gestation did not improve the ovulation rate, embryo survival or fetal development in gilts. Key words: Ovulation rate, embryo survival, flushing, fat, lysine, hormones, gilts
POSTPARTUM INTERVAL IN 10 FIRST-CROSSES OF BEEF COWS UNDER DRYLOT AND RANGE CONDITIONS
Authors: BAILEY D. R. C. , ENTZ T. , SWIERSTRA E. E.
Published: March 2010

The interval from parturition to first estrus was compared in mature F1 crosses of Hereford × Angus and those obtained by mating Charolais, Simmental and Limousin bulls to Angus, Hereford and Shorthorn cows. All cows, by breed cross, were confined to drylot from early October until early March, and subsequently were on range during calving from mid-March to early June. Half of the nursing cows from each breed cross group were returned to the drylot from mid-June until weaning in early October, while the others remained on range. In 1978, cows were fed 42% above NRC guidelines, whereas in 1979 and 1980 the ration was adjusted monthly in an attempt to achieve an average backfat of 5 mm for each breed cross. In 1978, 82% of cows were detected in estrus by the end of the 8-wk observation period, while in 1979 and 1980, all cows were detected in estrus. More cows were detected in estrus on range than in drylot, and the median postpartum anestrous interval (PPI) was shorter (P < 0.01) for cows on range than in drylot in 1978 (63 vs. 72 d). Mean days to first estrus for drylot and range were 52 and 52 d in 1979, and 58 and 57 d in 1980. PPI decreased (P < 0.01) by 3 and 5 d for every 10 d later in calving date in 1979 and 1980, respectively. PPI varied from year to year, was similar for different breed crosses, and was dependent upon winter and summer energy inputs in the drylot and on range. Key words: Postpartum interval, beef cows, breed crosses, drylot, range
ÉTUDE SUR LES PORCS DE RACE CONTRÔLÉS À LA FERME AU QUÉBEC. 1. SOURCES DE VARIATION
Authors: SAVOIE YVAN , MINVIELLE FRANCIS
Published: March 2010

Sources of variation for growth, for backfat and for a phenotypic index were studied in Quebec purebred Yorkshire, Landrace, Hampshire and Duroc pigs. A total of 94,161 records of backfat measures and of age and weight at the end of test, accumulated between 1977 and 1985, was used in this work. Weight at the end of test was found to be an important source of variation, so growth data were adjusted to 90 kg by linear regression (R2 between 31 and 52%). Gender, parity number, year-season, birth years of parents and herd were also significant factors. Therefore, they will be included as fixed effects in the mixed model to be used to evaluate heritabilities and genetic correlations. Key words: Pig, variation, environmental factors, home test
EFFECT OF GLUCOSE INFUSION ON METABOLIC AND REPRODUCTIVE FUNCTION IN POSTPARTUM BEEF COWS
Authors: McCAUGHEY W. P. , RUTTER L. M. , MANNS J. G.
Published: March 2010

An experiment was conducted to determine if glucose infusion could alter hypothalamic, pituitary or ovarian function in the postpartum (PP) beef cow. Twenty-six cows were assigned randomly at parturition to one of three infusion treatments. Controls (CON, n = 8) received 0.9% NaCl from days 26 to 32 PP. Glucose-infused animals (GLU, n = 8) received glucose at a constant rate of 4 mg min−1 kg−0.75 from days 26 to 32 PP, while glucose-spiked cows (SPIKE, n = 10) received glucose at rates up to 8 mg min−1 kg−0.75 for 48 h (days 26 and 27 PP), then received 0.9% NaCl as in CON. On day 32 PP 25 μg of gonadotrophin-releasing hormone (GnRH) was injected intravenously and blood samples were taken at 15- to 30-min intervals to evaluate pituitary release of luteinizing hormone (LH). During the entire infusion period, GLU had lower (P < 0.05) daily free fatty acid concentrations than either SPIKE or CON. Plasma concentrations of glucose in cows receiving the SPIKE treatment were elevated (P < 0.05) during the 48-h infusion period when compared to GLU and CON. In addition, glucose concentrations were higher (P < 0.05) in the GLU group than in the CON group during the first 48 h of infusion. For the remaining 4 d of the infusion period, plasma concentrations of glucose were similar between CON and GLU. Plasma insulin values were numerically but not significantly higher in GLU than in CON over the 6-d infusion period. During the 48-h glucose spike treatment insulin levels were elevated (P < 0.05) over preinfusion values and higher (P < 0.05) than both CON and GLU. Glucose infusion did not alter concentrations of plasma LH or the response to exogenous GnRH. The number of cows exhibiting ovarian activity by day 53 PP was similar among treatments. Key words: Beef cattle, glucose, reproduction, energy, luteinizing hormone, metabolism
DEVELOPMENT OF THE CIRCADIAN RHYTHM OF CORTISOL IN THE GILT FROM WEANING UNTIL PUBERTY
Authors: EVANS F. D. , CHRISTOPHERSON R. J. , AHERNE F. X.
Published: March 2010

In order to characterize the development of the adrenal axis by monitoring development of the circadian rhythm of cortisol, 10 gilts were blood-sampled serially for 24 h every 4 wk from 4 to 28 wk of age. Age at first estrus for sampled animals (199.6 ± 5.3 d, mean ± SEM) was not different (P > 0.05) from that of another group of 10 control gilts not blood sampled (203.4 ± 6.8 d). Cortisol profiles at 4 wk of age did not show a significant diurnal variation. At 8 and 12 wk, the profile showed the development of an afternoon trough. At 16 wk, an afternoon peak was present. At 20 and 24 wk, the continued development of peaks and a well-formed trough were evident and by 28 wk of age the profile was characterized by a large morning peak, small afternoon peak and an evening trough. Mean levels of total cortisol at 4, 8, 12, 16, 20, 24 and 28 wk were 25.3 ± 2.2, 37.4 ± 4.1, 40.1 ± 3.5, 26.8 ± 2.8, 20.6 ± 2.6, 38.3 ± 3.6 and 24.8 ± 2.9 ng mL−1, respectively. Profiles of biologically active cortisol appeared to closely mirror total cortisol profiles. Total cortisol levels at 8, 12 and 24 wk of age were higher (P < 0.05) than at other ages. These results indicate that in the gilt the circadian rhythm of cortisol undergoes gradual development reaching adult profiles at or shortly before first estrus. Key words: Adrenal, circadian rhythm, cortisol, cortisol binding globulin, development, gilt
SUPPLEMENTARY COPPER FOR GROWING CATTLE CONSUMING DIETS HIGH IN MOLYBDENUM OR MOLYBDENUM PLUS SULFUR
Authors: WITTENBERG K. M. , BOILA R. J.
Published: March 2010

Forty-eight Cu-depleted beef steers were used in a 105-d growing trial to compare four methods of Cu supplementation. Corn silage-barley concentrate diets were supplemented to contain 10 mg kg−1 dry matter (DM) Mo, and 1.3 (low S) or 3.7 (high S) g kg−1 total S. Copper treatments within low and high S diets were: (1) no supplemental Cu (0Cu); (2) a dietary supplement of 10 mg kg−1 DM Cu in the complete feed, added as CuSO4∙5H2O to the concentrate (CuSO4); (3) 20 g copper oxide needles (CuON) orally dosed on day 0; and (4) injectable Cu (ICu) on day 0. Although average daily gain was not different (P > 0.05) among Cu treatments, DM intake was lower (P < 0.05) with CuSO4 and CuON than with 0Cu or ICu. Feed efficiency (FE; feed:gain ratio) was better (P < 0.05) with CuSO4 (FE = 5.60) than 0Cu (FE = 6.88), while CuON (FE = 6.04) and ICu (FE = 6.16) FE were intermediate to 0Cu and CuSO4. Increasing dietary S from 1.3 to 3.7 mg kg−1 DM resulted in lower (P < 0.01) concentrations of Cu and Mo in liver and plasma, and plasma ceruloplasmin activity. An improvement of FE with CuSO4 was related to increased Cu and lower Mo concentrations in the plasma and liver of steers. With ICu there was some indication of an improvement of Cu status. With CuON, measured parameters were indicative of a metabolic Cu insufficiency, but with a lower concentration of Mo in plasma. At the levels of supplementation used in this trial, CuSO4 was a better Cu supplement than CuON or ICu for cattle consuming diets containing excess Mo or Mo plus S. Key words: Cattle, molybdenum, sulfur, copper sulfate, copper oxide needles, injectable copper
EFFECTS OF SODIUM BARBITAL ADMINISTRATION ON PERFORMANCE AND RATION DIGESTIBILITY OF YOUNG RUMINANTS
Authors: SEOANE J. R. , VIRCHEZ J. , CHRISTEN A.-M.
Published: March 2010

In a first experiment, nine lambs and nine kids newly born were used to study the effect of oral administration of sodium barbital (SB) on performance during weaning. All animals received three doses of SB (0,30 and 60 mg d−1) during weaning and 3 wk postweaning. During the 7-day weaning period, total dry matter intake (TDMI), in terms of percentage of body weight, was higher for animals receiving 30 or 60 mg of SB as compared to controls (P < 0.01). Average daily gain (ADG) of animals receiving SB was twice that of controls (P < 0.01), lambs performing better than kids (228 vs. 119 g, respectively, P < 0.01). Average feed conversion (FC) was also better for lambs than for kids (0.98 vs. 1.54 respectively, P < 0.01). After weaning, TDMI was higher in animals receiving SB (P < 0.03), with no differences observed between doses and species; however, treatment effects were apparent mainly during the first week and disappeared gradually afterwards. During the first week postweaning, ADG and FC were superior for animals receiving SB (P < 0.01 and P < 0.05, respectively). During this period, ADG of lambs was 78% higher than that of kids (P < 0.01). Apparent digestibilities of dry matter, crude protein and lipids were similar for all treatments and species. In a second experiment, eight lambs and eight kids were used to determine if oral administration of SB stimulates feed intake of growing ruminants. Lambs (30–45 kg) received 0, 120 or 160 mg of SB and kids (20–28 kg) were given 0, 80 or 100 mg of SB daily. Feed intake of lambs was not affected by administration of SB. Kids, however, ingested higher amounts of concentrate during the first 3 h after administration of 80 mg of SB. Daily feed intake was not affected. It appears that polyphagic-type drugs can be used effectively as feed additives during weaning to improve animal performance. The effect seems to be by a direct stimulation of feed intake without affecting ration digestibility. Key words: Barbiturate feeding, lambs, kids, polyphagia.
COMPARISON OF SIX COMMERCIAL HAY PRESERVATIVES UNDER SIMULATED STORAGE CONDITIONS
Authors: BARON V. S. , GREER G. G.
Published: March 2010

Rehydrated alfalfa (Medicago sativa L.) hay was used to test the effectiveness of six commercial hay additives in the laboratory. The additives were designated B1 (live bacterial culture, protease and cellulose enzymes) P1 (67% propionic acid partly neutralized with ammonia) R2 (25% propionic acid and unspecified amounts of other organic acids and flavorings), S (92% sodium sulphate), P3 (19% propionic acid and unspecified amounts of other organic acids and flavorings) and B2 (12% lactic acid and fermentation extract). The additives were assessed on their ability to prevent deterioration in in vitro digestible organic matter (IVDOM), heating and mould growth, loss of dry matter and associated parameters at hay moistures ranging from 15 to 35% moisture with additive rates specified by the manufacturer. After 21 d of storage and at all moisture levels P1 (1.25% wt wt−1) maintained IVDOM and most other parameters at levels similar (P ≤ 0.05) to an unspoiled Control at 15% moisture. P2 (0.2% wt wt−1) reduced heating and mould growth and maintained IVDOM to the levels of unspoiled hay up to 25% moisture. P3 (0.3% wt wt−1) provided slight improvements in IVDOM up to 25% moisture, but did not prevent heating. S (0.1% wt wt−1) limited dry matter loss at 20% moisture. Alfalfa hays treated with B1 (0.1% wt wt−1) or B2 (80 or 100 mL t−1 of dry matter) were not different from the control hay for any parameters. At 25% moisture B1 and B2 did not affect the growth of anaerobic and aerobic bacteria or moulds while P1 inhibited the growth of moulds and aerobic bacteria. Based primarily on maintaining consistently high IVDOM at ≥ 25% moisture the order of effectiveness was P1 > P2 = P3 > S = B1 = B2. The slight effects of P2 and P3 on IVDOM may not be evident in the field. Key words: Rehydrated alfalfa hay, in vitro digestibility, microbial changes
DEVELOPMENT OF LEGHORN PULLETS SUBJECTED TO EARLY LIGHT STIMULATION
Authors: LEESON S. , ETCHES R. J. , SUMMERS J. D.
Published: March 2010

Leghorn pullets of a commercial strain were reared in cages maintained in rooms providing either 8 or 14 h d−1 light. At 92 d, 12 birds identified as light (L) or heavy (H) weight from within each room were blood sampled for assay of plasma luteinizing hormone (LH). Subsequent samples were taken at 3- or 4-d intervals to 120 d of age. Another group of 12 L and 12 H birds were blood sampled at 92 d from within the 8 h light environment. These birds were again blood sampled at 99 d and then moved to laying cages and photostimulated with 14 h light per day. Birds were blood sampled for LH assay after 3 d and 7 d and then at 7-d intervals to 140 d of age. This general procedure was repeated with birds photostimulated at 102, 106, 109, 113, 116, 120, 123, 127 and 130 d of age. Thus, 10 groups of heavy birds and 10 groups of light birds were blood sampled prior to, at time of, and subsequent to light stimulation. Mean LH values for birds maintained on 18 h light throughout rearing were 1.5–2.0 ng mL−1 whereas with 14 h light throughout rearing values of 1.5–2.5 ng mL−1 were observed. Photostimulation had the same general effect on plasma LH regardless of body weight or bird age. After 3 or 4 d light stimulation there was a dramatic increase of some 100% in LH levels. Earlier photostimulation resulted in earlier age at 1st egg. For light weight birds, maturity was linearly advanced by 0.44 d for each day advance in photostimulation; a quadratic response was seen with heavy birds. Although photostimulation caused almost immediate changes in LH (P < 0.05) age at first egg lagged by some considerable time. These data do not indicate an absolute physiological (chronological) time limit for early sexual maturity, although it is likely close to 100 d of age. Key words: Pullet, luteinizing hormone, sexual maturity
THE RESPONSE OF MALE BROILER CHICKS TO THE CONSUMPTION OF LOW LEVELS OF CHLORTETRACYCLINE AS A GROWTH PROMOTER
Authors: PROUDFOOT F. G. , HULAN H. W. , JACKSON E. D.
Published: March 2010

Three thousand two hundred male broiler chickens were used to evaluate the efficacy of chlortetracycline (CTC) as a growth promoter when used in compliance with the present maximum feed-supplementation rate permitted in Canada (5.5 mg kg−1). No significant (P > 0.05) improvements in 21- and 42-d live body weights or feed conversion efficiencies were observed, regardless of the method of administration (feed or water). Changes to the sources of dietary calcium and phosphorus in an attempt to circumvent antibiotic inactivation by divalent cations also failed to potentiate any effect of this level of CTC. It is suggested that, if adequate attention is paid to the diet and health of broiler stocks, no further gains will be realized through feed supplementation with 5.5 mg kg−1 CTC. Key words: Diets, antibiotics, aureomycin, chlortetracycline, broiler chicken
THE USE OF PROSTAGLANDIN F2α IN NATURALLY BRED BEEF HEIFERS
Authors: COHEN R. D. H. , KING B. D. , JANZEN E. D.
Published: March 2010

Heifers injected with prostaglandin F2α had significantly higher pregnancy and conception rates within 11 d of start of breeding than noninjected heifers; 56.9 vs. 45.5 pregnancy as a percent of heifers exposed (P < 0.05) and 74.1 vs. 58.2 conception as a percent of pregnant heifers (P < 0.005). Data were pooled for 422 heifers over 5 yr. However, there were no significant effects on calving distribution or weaning weights of their calves. Key words: Prostaglandin F2α, natural breeding, heifer, estrus synchronization
FUTURE TRENDS IN RED MEAT PROCESSING—AN OVERVIEW
Authors: JONES S. D. M.
Published: March 2010

The major trend that has taken place in the meat industry is the increased availability of lean carcasses. Leaner carcasses result in improved processing productivity through lower energy costs for chilling and less labor to remove excess fat in the preparation of wholesale cuts. The introduction of new growth or efficiency promoting agents (beta-agonists, porcine somatotropin) will have major effects on livestock production with existing data showing potential gains in efficiency between 10 and 20% and a reduction in carcass fatness of 10–30%. Within the meat processing industry, a major change has been the closure of multispecies plants in favor of more specialized high throughput single species plants. Automation on the slaughter floor and in the cutting room are key areas for improving plant productivity. Hot processing of cuts on the slaughter floor offers major advantages in improving slaughter plant productivity. Research studies indicate that hot processing compared to traditional processing would require about 30% less chilling space, reduce the costs of cooling by 50% and need less labor to produce a final product. The meat processing industry faces the combined challenges of maintaining the quality of ultra-lean meat and adopting new technology to improve the efficiency of processing. Key words: Beef, pork, quality, grading, processing