bluuebunny/crossref_metadata_2025 huggingface dataset:
BEEF CATTLE REPRODUCTION IN RELATION TO THE ENVIRONMENT
Authors: FREDEEN H. T. , WEISS G. M. , RAHNEFELD G. W. , WARD DOUG , LAWSON J. E. , NEWMAN J. A.
Published: March 2010

Results are reported from a 10-yr study of lifetime reproductive performance of beef cows maintained under two contrasting environments. The data comprised records for 8160 cow years. The breeding herds were maintained for 6 yr in accordance with the management practices conventional to each location with winter management changed (to drylot feeding) for the final 4 yr. Location differences in cow performance favored the herd maintained under semi-intensive management (Brandon, Manitoba). Conception rates were higher, calf mortality lower, and calf gains preweaning greater than recorded for the contemporary herd maintained under extensive range management (Manyberries, Alberta). These differences in performance gave Brandon a 16% advantage in weight of calf weaned per mating exposure. Cows at Manyberries, in the fall of 1977, the seventh year of study, were lighter (15%) and had less fat (60%) than their Brandon contemporaries. These differences increased to 19 and 80% during the first winter in feedlot confinement even though the daily feed energy allowance was 20% above requirements (National Research Council-National Academy of Sciences, NRC-NAS). Conception rates at Manyberries were seriously affected by mortality, both cows and calves, inversely related to cow fat at calving. An increase in feed inputs at Manyberries (42% above NRC-NAS) the following winter, coupled with the opportunity for tissue restoration provided by a barren year, reversed the downward trends in weight and fat and weight equivalence of the two herds was achieved by 1980. Milk yields from pastured cows during the last 4 yr were generally higher for the Brandon herd, but calf growth rate from birth to 2 mo of age was greater at Manyberries. Key words: Beef cows, reproductive performance, lifespan, environment
REGRESSIONS OF PROGENY PROOFS FOR CALVING EASE AND GROWTH ON TEST STATION PERFORMANCE OF CHAROLAIS AND HEREFORD BEEF BULLS
Authors: CROW G. H. , AMAL S. , DONETZ M.
Published: March 2010

Performance records of 32 Charolais and 52 Hereford beef bulls tested at the Manitoba Bull Test Station for which progeny proofs were available (1984 Canadian Beef Sire Monitoring Program) were analyzed to determine if performance-tested bulls with progeny proofs were representative of the selected group of bulls which were eligible for sale (i.e, had station indexes of 95 or more) and to determine the regressions of progeny proofs on bull performance. The bull performance information included start and end of test weights, interim weights and gains, all expressed as deviations from their respective year-breed contemporary group means. This group of 84 bulls was not significantly different in test gains from the group of all bulls tested over the years 1976–1984 with station indexes of 95 or more. Regressions of progeny proofs for calving ease (CE, in score point units), preweaning gain (WG), yearling gain (YG) and postweaning growth (YG–WG) on bull weights and gains were estimated within breeds, weighting proofs by their prediction error variance. The only significant (P < 0.05) regressions of CE proof on bull performance were for bull weights in the Charolais group. Regression coefficients of WG and YG proofs on bull weights and gains were similar in magnitude with the coefficients for the Hereford breed being significantly different from zero more often than those for the Charolais breed. Effective heritabilities and genetic correlations between bull performance traits and progeny traits were estimated and, for traits defined similarly on parent and progeny, the estimates were similar to literature values. Test station procedures seemed to be effective in that bull performance was an indicator of subsequent progeny performance. Key words: Beef cattle, performance test, progeny test, heritability
THE INTERACTION OF COW SIZE WITH GROWTH POTENTIAL OF THE SERVICE SIRE
Authors: DINKEL C. A.
Published: March 2010

Weaning weight and individual feed records for 343 calves produced by 84 cows during an 8-yr period were utilized to evaluate the effects of high- and low-growth-potential sires on the efficiency of large and small cows. Cow efficiency was expressed as a ratio of cows' and calves' TDN consumption for a year divided by the weaning weight of the calf. The design allowed the mating of small and large cows of each of four breed groups to unrelated low- and high-growth-potential bulls. The effects of cow size on cow efficiency were further evaluated by omitting cow size group and the interaction of cow size with sire group from the model and replacing them with the linear and quadratic effects of cow weight and subclass regressions of efficiency on cow weight within sire groups. Results indicated no interaction of cow size with growth potential of the bull, and no effect of cow size group but a significant effect of growth potential of the bull. The inclusion of milk production as a dependent variable indicated that cows produced 0.6–0.8 kg d−1 more milk when bred to the high-growth-potential bull group. None of the quadratic or linear regression coeficients were significant but the subclass regression of cow efficiency on cow weight within the high-growth-potential bull was significantly different from zero and from the coefficient for low-growth-potential bulls. These effects were in the direction which agrees with the concept of complementarity but their values were rather small. Further experimental evaluation of this kind with greater range in weight of sire and dam would be desirable. Key words: Cow efficiency, complementarity, beef cattle
BODY PROPORTIONS AND CARCASS COMPOSITION OF PIGS WITH KNOWN GENOTYPES FOR STRESS SUSCEPTIBILITY FASTED FOR DIFFERENT PERIODS OF TIME PRIOR TO SLAUGHTER
Authors: JONES S. D. M. , MURRAY A. C. , SATHER A. P. , ROBERTSON W. M.
Published: March 2010

A total of 233 pigs from a halothane positive line (genotype nn), from a halothane-negative line (genotype NN) and their cross (genotype Nn) were allocated to three treatments when their liveweight approximated 95 kg. Treatment 1 consisted of immediate slaughter following removal of the pigs from their pens, treatment 2 involved a period of 24 h of feed restriction prior to slaughter and treatment 3 a period of 48 h of feed restriction prior to slaughter. All carcasses were weighed on the slaughter floor and cooled at 1 °C for 24 h prior to dissection of the side into fat, lean and bone. Relative to liveweight, nn pigs had a higher proportion of carcass (41 g kg−1, P < 0.001) and a lower proportion of body organs (8 g kg−1, P < 0.001), body fat depots (7 g kg−1, P < 0.001), alimentary tract (14 g kg−1, P < 0.001) and gutfill (12 g kg−1, P < 0.001) than NN pigs. Nn pigs had values that were generally intermediate to nn and NN pigs. The proportion of carcass (22 g kg−1), body organs (5 g kg−1), alimentary tract (6 g kg−1) and gutfill (21 g kg−1) were reduced (P < 0.05) as fasting increased from 0 to 48 h relative to market weight. Linear fat thickness measurements made on the midline of the warm carcass were similar for nn and NN pigs except for the maximum loin (32.2 vs 28.6 mm for nn vs. NN). However, nn pigs had a lower proportion (P < 0.05) of fat (35 g kg−1), bone (13 g kg−1) and skin (11 g kg−1), and a higher proportion of lean (60 g kg−1) in their carcasses than those from NN pigs. Carcasses from Nn pigs had less skin (4 g kg−1) and bone (7 g kg−1), but more lean (11 g kg−1) and similar fat content to those from NN pigs. It was concluded that fasting for up to 48 h prior to slaughter had a similar effect on the three genotypes, but there were large differences among genotypes in body components and carcass composition. Key words: Stress susceptibility, fasting, carcass, organs, gutfill, composition, pigs
EFFECT OF LINECROSS AND DELAYED CASTRATION ON GROWTH AND CARCASS TRAITS IN BOARS AND BARROWS
Authors: McKAY R. M. , CLIPLEF L. R.
Published: March 2010

The effects of linecross, castration treatment, and linecross × castration treatment interaction on live animal growth and carcass attributes were determined on data from 212 male pigs. The linecrosses were derived from randomly mating Landrace boars to Yorkshire control, Yorkshire select, and Hampshire select (LHs) sows and castration treatments were: no castration (IB, intact boars), early castration (EC, mean of 12 d, range from 10 to 14 d of age), and late castration (LC, mean of 100 d, range from 97 to 104 d of age). The traits studied were subdivided into general carcass traits, loin traits, hindleg traits, cooked semitendinosus traits, and interactions. Linecross differences were (LYc = LHs) < LYs — carcass length and percent pressed fluids in cooked semitendinosus; LYs < (LHs = LYc) – percent cooking loss; LHs < LYs < LYc – backfat thickness and leaf fat weight; LHs < LYc < LYs – percent biceps femoris weight and moisture in cooked semitendinosus; LHs<(LYc=LYs) – pH and percent protein; LYc < (LHs = LYs) – hindleg weight; (LHs = LYs) < LYc – percent gastrocnemius weight; (LYc = LYs) < LHs – percent foot and skin of the hindleg; LHs < LYc – loin weight; LHs < LYs – percent absorption and moisture in the longissimus muscle; and LYs < LHs – percent ether extract in the longissimus muscle, average shear, and percent semimembranosus. Differences among castration treatments were: IB < (EC=LC) – backfat thickness, leaf fat and loin weights, percent fat weight of the hindleg, and percent ether extract in cooked semitendinosus; (EC = LC)<IB – carcass length, kidney and hindleg weights, carcass shrink, weights of foot, skin, bone, and lean tissue as percents of hindleg, and lean/fat separation, marbling, firmness, and odor scores; LC < IB – loin eye area and average shear; EC < IB – texture score and percent semimembranosus weight; IB < EC – percent cooking loss; and LC < EC – percent pressed fluids in cooked semitendinosus. Linecross × castration treatment interactions were found for postweaning average daily gain, percent lean in the ham face, two-tone score of the ham, and percent semitendinosus weight. Key words: Pigs, boar, linecross, castration, carcasses, growth
PLASMA INSULIN AND GROWTH HORMONE IN GROWING LAMBS FED MONENSIN
Authors: MEARS G. J. , VESELY J. A. , CHENG K.-J.
Published: March 2010

Plasma insulin and growth hormone (GH) were measured in 62 monensin-treated lambs and 59 control lambs from four experiments that were conducted to determine the effect of monensin treatment on average daily gain (ADG) and gain to feed ratio (G:F). Plasma GH concentrations were lower in lambs that received monensin (P < 0.05–0.01). The effect was greater in ram than in ewe lambs (P < 0.03). Monensin treatment started when lambs were only a few weeks old and resulted in a more rapid GH response than when older lambs were treated. In some, but not all, of the experiments the lower plasma GH concentrations occurred in conjunction with an increase in ADG and an apparent increase in G:F. Monensin had little effect on plasma insulin concentrations. Key words: Lambs, monensin, growth hormone, insulin
FORAGE PRODUCTION AND UTILIZATION IN VARIOUS TOPOGRAPHIC ZONES OF THE FESCUE GRASSLANDS
Authors: WILLMS W. D.
Published: March 2010

The effects of topography and litter on forage production and utilization were studied on Rough Fescue Grasslands in the foothills region of southwestern Alberta. Forage production and utilization were estimated, at monthly intervals during the grazing seasons over 4 yr, in six topographic zones of two fields stocked at a moderate or a high rate representing 2.4 or 3.2 animal unit months per hectare (AUM ha−1), respectively. The higher rate could not be achieved in the first 3 yr of the study because available forage was limiting. The topographic zones were represented by the west, east, south, and flat aspects of the upland areas, and by the lowland zone subdivided into a subirrigated zone and the interface between the latter and upland zones. Forage production was about 50% more in the subirrigated zone than in the upland zones. Among the upland zones, forage production tended to be greatest on the south aspect. Forage utilization was greatest in the subirrigated zone but least on the south aspect. Topographic preference was highest for the subirrigated zone early in the grazing season. The effect of a high stocking rate was to minimize the preference differences among topographic zones. Litter had a significant positive effect on both forage production and the amount of residual forage after the grazing season but had a significant negative effect on percent utilization. Litter provided a buffer which enabled the maintenance of anticipated stocking rate by providing emergency forage and enhancing production during drought. Key words: Litter, residual forage, preference, aspect, stocking rate, cattle, distribution
DIGESTIBILITY AND ACCEPTABILITY OF POTATO STEAM PEEL BY PIGS
Authors: NICHOLSON J. W. G. , SNODDON P. M. , DEAN P. R.
Published: March 2010

Potato steam peel is a by-product of the production of frozen french fry potatoes. As produced, it typically has 14% dry matter with 15% crude protein and 6% ash (dry matter basis) and a pH of 5.8. The starch is partially denatured and there is no proteolytic enzyme inhibitor activity. The feeding value of steam peel for pigs was evaluated through chemical analyses, a digestibility trial and a feeding trial. Its digestibility (%) by pigs was found to be dry matter 81.1 ± 2.8, crude protein 61.3 ± 3.7, organic matter 82.4 ± 3.0 and energy 76.8 ± 6.0. In the feeding trial carried out on a commercial hog finishing farm, feed consumption was markedly reduced when the steam peel was included at over 30% of the ration dry matter at the start of the trial. The inclusion of steam peel at 15, 20 or 25% of the ration dry matter reduced the average daily gain and feed efficiency (P < 0.05). However, it was concluded that potato steam peel can be used at up to 25% of the diet for growing fattening pigs with little detrimental effect on the level of animal performance. Key words: Potato, steam peel, pigs
FETAL PIG DEVELOPMENT IN SOWS FED DIETS CONTAINING DIFFERENT FATS
Authors: FARNWORTH E. R. , KRAMER J. K. G.
Published: March 2010

Fetuses (57, 85, 110 d gestation) from sows fed experimental diets from day 57 of gestation were examined. Sows ate either a diet with no added fat (2.6% total lipid), or a diet containing added soybean oil (4.7%) or tallow (5.0%). The diet of the sow was shown to have no effect on fetal organ (heart, liver, lung, kidney) size or total fat content. Fetal carcass proximate analysis was likewise unaffected by changes in the maternal diet. Key words: Pig, fetus, diet, development
EFFECT OF AMBIENT TEMPERATURE AND DIETARY ENERGY ON THE PERFORMANCE OF TURKEY BROILERS
Authors: PROUDFOOT F. G. , HULAN H. W.
Published: March 2010

Performance of male and female turkey broilers was compared up to 93 d of age when housed in one of three ambient temperature environments and fed one of four dietary regimens differing in energy levels. Feed conversion ratios were improved in the high-temperature environment, but feed intake and body weights were reduced. Higher dietary energy levels resulted in improved feed conversion ratios and heavier body weights except for the dietary regimen with the highest energy level. Temperature × dietary energy and sex × temperature × dietary energy interactions for body weights and feed conversion indicated that the dietary energy requirement may have been reduced in warmer environments, particularly for females. Key words: Energy, turkey, broiler, temperature
LIVE PERFORMANCE, CARCASS AND MEAT QUALITY CHARACTERISTICS OF MARKET PIGS SELF-FED DIETS CONTAINING CULL-GRADE LENTILS
Authors: CASTELL A. G. , CLIPLEF R. L.
Published: March 2010

Lentils rejected for use as human food were evaluated as an alternative to soybean meal (SBM) in barley-based diets containing 16% crude protein (CP). The first study involved 64 male castrates (four pigs/pen) fed diets containing 0, 5, 10 and 20% Laird lentils (LL, 23 % CP) ad libitum from 25 to 97 kg liveweight in a randomized block design with four replicates. Growth rates (mean of 914 g d−1) were similar on all diets but pigs fed the 10% LL diet were the most efficient (366 vs. 354 g gain kg−1 diet, P < 0.05), had thinner backfat (15.7 vs. 17.7 mm at 90 kg liveweight, P < 0.05) and more acceptable (P < 0.05) meat quality by physical and sensory evaluation compared to control (0% LL) pigs. The subsequent study, a one-way factorial design with four replicates using 60 gilts (3/pen) and five diets containing 0, 10, 20, 30 and 40% Eston lentils (EL, 27% CP), was similarly conducted over the period from 25 to 90 kg liveweight. As observed previously, dietary lentils promoted curvilinear responses (usually optimum at 20% EL) although there were few significant (P < 0.05) differences between lentil-fed and control pigs apart from their meat quality criteria. Taking into account the costs of barley and SBM replaced, the value of cull lentils in each study was maximum at the 10% inclusion rate. Key words: Pig, growth, carcass, meat quality, lentils
CORRELATIONS BETWEEN ADJACENT TEST DAYS FOR FAT PERCENT, FAT YIELD AND MILK YIELD
Authors: LEE A. J.
Published: March 2010

Retest data from the Record of Performance for dairy cattle were used to examine the day-to-day and month-to-month variation in fat percent, fat yield and milk yield and the effect of stage of lactation on this variation. The overall correlation between fat percent on successive days (retest day) was low (0.71) in Holsteins compared to that for fat yield (0.85) and milk yield (0.96). Correlations between values on either test day or retest day with those on the next test day (1 mo later) were 88–90% of those between successive day values for milk yield and fat yield but only 73% for fat percent. Correlations of fat percent on the next test day with those on the original or retest day were particularly low (< 0.40) for the first 60 d in milk. Fat percent is much more variable from day to day and from test day to test day than milk yield or fat yield, particularly in early lactation. Key words: Dairy, test-day, correlations, milk, fat
RESPONSE OF PIGLETS TO SUBOPTIMAL PROTEIN DIETS SUPPLEMENTED WITH LYSINE, METHIONINE, THREONINE AND TRYPTOPHAN
Authors: CINQ-MARS DANY , GOULET G. , BRISSON G. J.
Published: March 2010

A 4-wk feeding trial was conducted with castrated piglets weaned between 18 and 21 d of age, and fed either 22, 29 or 17% crude protein isocaloric diets, adjusted to the same calculated content for total lysine, methionine, threonine and tryptophan. Piglets fed the 22 or 19% protein diets had the same feed intake, practically the same growth rate, and the same gain/feed ratio. Those fed the 17% protein diet had the same feed intake, but gained less than those fed the 19% protein diet. Therefore, it seems possible to lower the protein content of a weanling diet from 22 to 19%, provided that lysine, methionine, threonine, and tryptophan are adjusted to the same calculated content. Key words: Piglets, lysine, methionine, threonine, tryptophan
THE RELATIONSHIP OF LIVE ULTRASONIC PROBES TO CARCASS FAT MEASUREMENTS IN SWINE
Authors: SATHER A. P. , TONG A. K. W. , HARBISON D. S.
Published: March 2010

Measurements of total fat depth and depth to the interface between the second and third fat layers were made on live pigs just prior to slaughter and on their hot and cold carcasses. The data were analyzed to predict the changes that would take place in these measures of fat depth during slaughter and carcass cooling. A statistical interaction was detected between slaughter weight and the animal/carcass state at the time of measurement for the total fat measurement only. This suggests that measurements taken to the interface of the second and third fat layers will exhibit a more consistent relationship between live animal and carcass values. Key words: Swine, ultrasonic probes, slaughter weight, carcass fat
COMPARISON OF ANABOLIC IMPLANTS ON REPRODUCTIVE FUNCTION, PERFORMANCE AND CARCASS CHARACTERISTICS IN WEANED BEEF BULLS
Authors: GORDON S. J. , MILLER H. L. , GEE D. H. , EVENSON D. P.
Published: March 2010

Sixty-six Angus bulls, averaging 7 mo of age and 282 kg were utilized to study the effects of implants on performance, carcass characteristics and reproductive function of intact males. Bulls were randomly assigned to one of four treatments, nonimplanted (N), 36 mg of Ralgro® (R), 220 mg of Synovex-S® (S) or 24 mg of Compudose® (C). Bulls remained on test for 217 d. Blood samples were analyzed for testosterone, growth hormone (GH) and luteinizing hormone (LH). Nonimplanted bulls had larger (P < 0.05) final scrotal circumference (39.0 vs. 37.7 cm) than S-implanted bulls, but were not different from R (38.8 cm) or C (38.6 cm) bulls. No differences were detected in sperm chromatin structure among treatment groups as determined by flow cytometry. There were no treatment differences in average daily gain, feed per gain, testicular weight, and testosterone or LH levels. Synovex implanted bulls had higher GH levels (P < 0.05) compared to N bulls, but were not different from C or R groups. Carcasses from C (331 kg) and S (332 kg) were heavier (P < 0.05) than those from R (307 kg) but not different from N (318 kg) animals. Fat thickness at the 12th rib was greater (P < 0.01) for S (11.6 mm) than N (9.0 mm), C (8.8 mm) and R (8.3 mm) treatments. The greater fat thickness of S bulls increased the yield grade compared to N and C (P < 0.05) and R-treated bulls (P < 0.01). Dressing percent was higher (P < 0.05) for C (63.2%) and S (62.6%) than R (61.7%) and N (61.0%) groups. No differences were detected for longissimus muscle area or USDA quality grades. Key words: Implants, beef bulls, sperm chromatin structure, carcass, hormones
EFFECT OF MUZZLING ON RUMINATION IN SHEEP
Authors: CHAI K. , MILLIGAN L. P. , MATHISON G. W.
Published: March 2010

Two experiments were completed using four esophageal-fistulated sheep (two per experiment) to study the breakdown of rumen particles of grass hay (bromegrass or reed canarygrass) when rumination was either allowed to occur normally or was restricted by means of a muzzle. When the sheep were muzzled during the nonfeeding portion of the day, there was a distinct limitation of voluntary hay intake. Muzzled sheep chewed more often than unmuzzled sheep (P < 0.01) during eating and, presumably as a result, the particles in their mastication boluses were smaller (P < 0.05). During rumination the regurgitated and chewed boluses from sheep that had been muzzled were larger (P < 0.05) than those from unmuzzled sheep. The proportion of large particles (LP, particles retained on a 1.00-mm screen) of the regurgitated bolus, rumen contents and feces were greater (P > 0.05) for muzzled than unmuzzled sheep. The effectiveness of breakdown of LP retained for chewing during the rumination cycle increased (P < 0.005) with time after feeding (33% at 3 h postfeeding for bromegrass; 57% at 11 h postfeeding). This increase was eliminated by muzzling. The specific fragility (LP breakdown per chew per unit of LP in mouth) of particles from unmuzzled sheep was consistently greater (P > 0.05) than that of particles from muzzled animals. Muzzling markedly reduced the extent to which specific fragility increased with time after feeding and increased (P > 0.01) rumen fluid retention time from 7.4 to 17.4 h. The rumen input-output balance for hay particles was estimated. It is concluded that rumination is the major factor in decreasing the size of forage particles in the rumen, thereby exposing greater surface area to microbial attack and facilitating passage along the intestinal tract. Key words: Sheep, rumination, muzzle, particle breakdown, specific fragility, rumen retention time
NUTRITIVE VALUE OF PULP MILL FIBER WASTE FOR RUMINANTS
Authors: CROY D. S. , RODE L. M.
Published: March 2010

Two experiments were conducted to determine the feeding value of pulp fiber waste (PFW) from British Columbia pulp mills. In the first experiment, PFW from 10 mills was analyzed for chemical constituents and in sacco digestion in the rumen of steers. Dry matter (DM), organic matter (OM) and lignin contents ranged from 15.6 to 35.2%, 42.5 to 96.3% and 2.2 to 50.7%, respectively. Nitrogen content was low (< 0.1% N) in all samples. Neutral detergent fiber (NDF) content accounted for virtually all non-ash DM. Several PFW samples contained levels of Ca, Na, Al, Cd and Pb sufficiently high to be of concern if fed to ruminants. Five of the 10 samples of PFW surveyed contained mineral levels in a range suitable for feeding to ruminants and were observed to have 24-h in sacco digestibilities of >50%. These criteria were used to determine if a particular sample of PFW was suitable as a substitute for forage. In the second experiment, steers were fed red clover-timothy silage substituted with 0, 12, 24, 36 and 48% PFW from one of the mills. Digestibility of DM, OM, acid detergent fiber (ADF) and NDF in the diets increased linearly (P < 0.01) with increasing level of PFW in the diet. Digestibilities estimated by regression analysis for PFW were 79.7, 84.0, and 95.7% for DM, OM, and NDF, respectively. Voluntary intake of DM decreased linearly (P < 0.05) with increasing PFW in the diet but intake of digestible DM declined only at the highest level of PFW in the diet. These results indicate that PFW from certain pulp mills can be used successfully as forage substitutes for ruminants. Keys words: Cattle, cellulosic waste, wood, digestibility, in sacco
THE PERFORMANCE OF DAIRY AND FEEDLOT CATTLE FED SULFUR DIOXIDE-TREATED HIGH-MOISTURE BARLEY
Authors: GIBSON D. M. , KENNELLY J. J. , MATHISON G. W.
Published: March 2010

Two experiments were conducted to determine the influence of feeding sulfur dioxide (SO2)-treated high-moisture barley (HMB) on the performance of lactating dairy cows and feedlot cattle. High-moisture barley was ensiled or treated with 1% (wt/wt) liquid SO2. In exp. 1, 36 lactating Holstein cows were assigned to three treatments for a 6-wk trial. Diets contained 35% rolled barley on a dry matter (DM) basis and differed only in the type of barley fed: dry barley, ensiled HMB or SO2-treated HMB. While no differences (P > 0.05) were observed in DM intake, milk yield, milk composition, milk taste or odour, cows fed SO2-treated HMB tended to have lower milk yield (21.7 kg d−1) than those fed ensiled (22.6 kg d−1) or dry barley (24.6 kg d−1). In experiment 2, 64 steers were allotted to four dietary treatments: (1) dry barley, (2) ensiled HMB, (3) SO2-treated HMB, and (4) SO2-treated HMB plus sodium bicarbonate. All diets contained 85% barley (DM) and were supplemented with thiamin (5.5 mg kg−1 DM). The results of the feedlot trial were confounded by the feeding of spoiled SO2-treated HMB, primarily between days 29 and 57 of the 96-d trial, at approximately 40% of the diet DM. During the period that spoiled SO2-treated grain was being fed, four steers (two from each treatment) developed polioencephalomalacia. Steers fed SO2-treated HMB (diets 3 and 4), had 10.1% lower DM intake (P < 0.01), 31% lower average daily gain and required 32% more DM per kilogram of gain than steers fed diets 1 or 2 (P < 0.001). Feeding SO2-treated HMB to either dairy or feedlot cattle cannot be recommended at the present time. Key words: Sulfur dioxide, preservative, barley, cattle (dairy, beef)
DIGESTIBILITY AND ACCEPTABILITY OF OAC WINTRI TRITICALE BY GROWING PIGS
Authors: LUN A. K. , SMULDERS J. A. H. M. , ADEOLA O. , YOUNG L. G.
Published: March 2010

The digestibility and acceptability of OAC Wintri triticale were evaluated in two trials. In trial 1, three diets in which triticale replaced 0, 50 or 100% of corn were fed to 12 barrows individually housed in digestion crates. No significant difference was observed in dry matter digestibility among diets. Daily fecal nitrogen, daily absorbed nitrogen and apparent protein digestibility adjusted to equal nitrogen intake responded quadratically (P < 0.01) to increasing levels of triticale in the diets. There were no significant differences in daily retained nitrogen, apparent biological value or net protein utilization among diets. Gross energy digestibility, digestible energy (MJ kg−1) or metabolizable energy (MJ kg−1) were not different among diets. The second trial involved pair-feeding 48 pigs (average initial weight 36.7 kg) for 28 d to ascertain the acceptability of triticale to pigs utilizing the same diets as in trial 1. Increasing levels of dietary triticale resulted in a linear reduction (P < 0.001) in feed consumption and growth rate with pigs fed ad libitum. Feed efficiency was poorest when pigs consumed the highest level of triticale. The pair-feeding experiment indicated that pigs fed the diet in which triticale replaced 100% of the corn had a lower growth rate than pigs fed the corn diet even though feed intake on the two diets was similar. In summary therefore, all diets had a similar digestibility. OAC Wintri triticale was less acceptable to pigs, presumably due to poorer palatability, and resulted in lower daily gain than corn. The pair-feeding trial indicated that unknown antinutritional factors may be responsible for part of the poor performance of pigs fed this variety of triticale. Key words: OAC Wintri triticale, digestibility, acceptability, performance, growing pigs
OVIPOSITON IN LAYING HENS: AMENABILITY TO OPERANT CONDITIONING
Authors: LUESCHER U. A. , HURNIK J. F.
Published: March 2010

Laying hens were rewarded for oviposition with 20 min access to feed under continuous and multiple reinforcement schedules. Oviposition times, laying performance, egg quality traits and behavior did not differ between experimental birds and yoked controls. Results are discussed in terms of associative and system constraints, as well as experimental procedures. Key words: Operant conditioning, oviposition, laying hens, behavior
EFFECT OF COMPLETE DRY COW TREATMENT ON MASTITIS CONTROL IN DAIRY CATTLE
Authors: BATRA T. R.
Published: March 2010

Data on 297 cows which received complete dry cow treatment and subsequently calved were used in this study. At drying-off, 7.7% of the quarters were infected. Among the mastitic pathogens, Staphylococcus aureus was isolated in 75% of the infected quarters. About 92% of the infected quarters were cured with dry cow treatment and 6% of the quarters had new infections during dry period. It appears that dry cow treatment is an effective means of eliminating Staphylococcus aureus infections. Key words: Mastitis, dry cow treatment, dairy cattle
INSERTING A RUMEN CANNULA IN SHEEP TO MINIMIZE LEAKAGE
Authors: GROVUM W. L.
Published: March 2010

Leakage from rumen cannulae was controlled almost totally in sheep by inserting a disc of surgical-grade mesh tightly over the cannula stem at the time of surgery so that it was interposed between the serosa of the rumen and the peritoneum. The approach was inexpensive and, in our experience, improved the welfare of the sheep. Key words: Sheep, ruminants, rumen cannulae, leakage, welfare
SEASONAL VARIATION IN THE BLOOD CONCENTRATION OF 16-ANDROSTENES IN ADULT LANDRACE BOARS
Authors: TRUDEAU V. L. , GRINWICH D. L. , SANFORD L. M.
Published: March 2010

The influences of season and social environment on the blood concentration of 16-androstenes were examined for the boar in relation to testosterone concentration. Adult Landrace boars were penned individually in the vicinity of gilts that were brought into estrus every 2 wk. Boars either did or did not have visual and limited physical contact with these gilts which were penned individually adjacent to the boars. The blood concentration of 16-androstenes was generally comparable to that of testosterone concentration, but fluctuated very little with season (month, P < 0.10). In contrast, testoter-one concentration varies with season in somewhat different patterns for these two groups of boars (group × month, P < 0.05). Key words: 16-androstenes, testosterone, blood, boar, season, social environment
MIXING OR ALTERNATING DIETARY CRUDE PROTEIN SOURCES AND PERFORMANCE OF WETHER LAMBS
Authors: DUFF G. C. , GOETSCH A. L. , LANDIS K. M. , HARDIN A. C. , STOKES S. R. , JOHNSON Z. B. , HALL K. L.
Published: March 2010

Effects of mixing or daily alternation of dietary cottonseed (CS), corn gluten (CG) and soybean (SB) meals on wether performance were determined. Feed intake tended to be lowest for CG fed continuously. Daily gain (g) was 260, 342 and 327 for CG, CS and SB, 335, 329 and 317 for CG-CS, CG-SB and CS-SB mixes, and 269, 312 and 342 for CG then CS, CG then SB and CS then SB on alternate days, respectively. Feed:gain ratios did not differ among treatments. Key words: Sheep, performance, protein sources, feeding method
THE SULFATE CONTENT OF WATER FOR CATTLE THROUGHOUT MANITOBA
Authors: BOILA R. J.
Published: March 2010

The sulfate content of water that may be used by cattle throughout Manitoba was examined. Water in rivers, and lakes with an inflow and outflow, rarely had sulfate concentrations greater than 500 mg L−1, and would not be detrimental for cattle. Groundwater, and water in potholes and landlocked lakes at many sites, however, had sulfate levels in excess of 1500 mg L−1, which can be considered excessive for cattle. Key words: Water, sulfate, sulfur, cattle, Manitoba
THE EFFECT OF MIXING STRESS ON THE INCIDENCE OF OSTEOCHONDROSIS IN PIGS: SCANNING ELECTRON MICROSCOPY
Authors: WALKER B. , AHERNE F. X.
Published: March 2010

The object of this study was to determine the effect of mixing stress on the development of osteochondrosis, using scanning electron microscopy. Sixteen litters of eight pigs per litter were randomly assigned to one of four different treatment groups involving combinations of preweaning handling and postweaning mixing stress. Before weaning, all pigs were subjected to normal handling procedures, but one of the groups was handled with exceptional care. After-weaning treatments involved various amounts of mixing stress varying from no mixing to mixing every month. All pigs received standard starter, grower and finisher diets ad libitum (19, 16 and 14% crude protein, respectively). Eight pigs from each of the four treatment groups were randomly selected for slaughter at 3, 4, 5 and 6 mo of age. After slaughter elbow and knee joints were examined grossly and histologically by light and scanning electron microscopy for evidence of osteochondrosis. Handling and mixing stresses had no significant effect on performance in the grower or finisher periods. Mixing stress had no significant effect (P > 0.05) on the average lesion scores of cartilage from any of the sites studied. No differences were apparent under light microscopy in the morphology of humeral and femoral condylar cartilage of pigs from any of the treatment groups. Under scanning electron microscopy the surface of normal porcine condylar cartilage appeared very smooth with numerous clusters of chondrocytes evidenced by small protrusions from the surface. Pigs from the two mixed treatment groups showed extensive surface wear (osteoarthrosis) at the age of 6 mo. The results indicated that mixing stress had little effect on the incidence of osteochondrosis but may be involved in the progression of osteoarthrotic changes with advancing age. Key words: Scanning electron microscopy, swine, osteochondrosis, mixing stress
USE OF WATER BY PIGLETS IN THE FIRST DAYS AFTER BIRTH
Authors: FRASER DAVID , WEEM W. B. PEETERS , PHILLIPS P. A. , THOMPSON B. K.
Published: March 2010

Use of drinking water was determined for 51 litters of piglets by weighing and refilling a water dispenser each day for the first 4 d after farrowing. Measures of spillage, evaporation, and piglet drinking behavior indicated that most disappearance of water represented actual drinking by the piglets. Water use varied greatly among litters with an average of 46 g d−1 per piglet over the 4 d, and a range of negligible use to about 200 g d−1. Water use, especially on day 2, was correlated negatively with the average weight gain of the litter during the first 2 d (r = −0.45, P < 0.001). Litters that lost weight or gained very little on days 1 and 2 showed a pronounced peak of water use on day 2 (averaging about 100 g d−1 per piglet), with declining use on days 3 and 4. In contrast, litters with high initial weight gains drank little water on days 1 and 2 but showed a steady increase in water use to day 4. The results suggest that piglets will drink appreciable amounts of water on the first days after birth especially if their milk intake is limited. We speculate that under these circumstances water intake may help to prevent dehydration and promote survival of piglets with low early milk intake. Key words: Piglet, water, drinking, agalactia, dehydration, body weight
ALTERNATIVE SELECTION CRITERIA FOR THE GENETIC IMPROVEMENT OF FEED EFFICIENCY IN BROILER CHICKENS
Authors: IRWIN L. N. , FRIARS G. W. , JULIAN R. J.
Published: March 2010

A hierarchical mating of 25 sires and 192 dams produced 862 progeny that yielded complete records to market age in two hatches of broiler chickens. These progeny were housed in two levels of cages. Half of the birds were subjected to a compensatory feed treatment which was used as an indicator of appetite. Increased feed consumption, following fasting, resulted in increased deposition of abdominal fat. Various approaches were investigated with respect to maximizing the genetic improvement of feed efficiency. Estimates of the heritabilities of feed:gain, gain:feed, total feed intake, compensatory feed intake and compensatory gain were all low (0.24 or less), with generally high standard errors. The estimated heritabilities of gain and gain corrected for feed intake at 0.46 suggests that selection for the latter trait has potential for improving gain at a statistically fixed feed intake. The standard errors on estimates of genetic correlations were too wide to allow predicted selection changes in correlated traits, and thus these correlations were not presented. Key words: Broiler chickens, feed efficiency, compensatory feed intake, abdominal fat deposition
GROWTH HORMONE, INSULIN, PROLACTIN, GLUCOSE AND MONONUCLEAR LEUKOCYTE INSULIN BINDING RESPONSES TO CLONIDINE IN RAM LAMBS
Authors: KENNEDY A. D. , TEKPETEY F. R. , ONISCHUK L. A.
Published: March 2010

Concentrations of growth hormone, insulin, prolactin and glucose were measured in blood taken frequently, over a 12-h period on three occasions (phases 1, 2 and 3) during a 72-d growth trial, from Suffolk (SU) and Strain 2 (ST) (a synthetic Finnish Landrace, Suffolk, Shropshire line) lambs treated continuously with either sterile H2O (control) or a low dose (5–8 μg kg−1d−1) of clonidine (LC). Prior to slaughter the specific binding of insulin to mononuclear leukocytes (MNL) was measured in SU and ST control and LC lambs and in SU and ST lambs treated for 72 d with a high dose (HC) of clonidine (24–41 μg kg−1d−1). Clonidine was administered using osmotic pumps implanted subcutaneously at 28-d intervals. Overall mean and baseline concentration of serum prolactin increased in SU and decreased in ST lambs in response to LC. Serum insulin increased over time in SU control lambs and decreased over time in ST control lambs. Serum insulin increased with LC treatment but the effect appeared earlier in ST lambs. Growth hormone (GH) profile characteristics were similar for control ST and SU lambs in phase 1 and GH overall mean, baseline and peak frequency decreased over time. The decrease was most pronounced in ST lambs. The low dose of clonidine reduced GH concentration and this effect was most pronounced in phases 2 and 3 for SU lambs and in phases 1 and 2 for ST lambs. Insulin specific binding to MNL at low insulin concentrations was threefold greater in SU than ST control lambs. Treatment with LC and HC depressed insulin specific binding to MNL at low insulin concentrations in SU lambs but the opposite effect was observed in ST lambs. The results suggest that the breed effect on endocrine responses to clonidine may underlie the previously reported effect of breed on carcass responses to clonidine. Key words: Clonidine, insulin, growth hormone, prolactin, receptors
REPRODUCTIVE PERFORMANCE, FETAL GROWTH, CARCASS COMPOSITION AND GLUCOSE TOLERANCE IN PREGNANT GILTS GIVEN A DIETARY PROTEIN SUPPLEMENT
Authors: SCHAEFER A. L. , JONES S. D. M. , NEWMAN J. A. , SATHER A. P. , TONG A. K. W.
Published: March 2010

The purpose of this study was to employ carcass and nucleic acid analyses to examine nutrient partitioning among maternal, fetal and placental tissues at mid-gestation in protein-supplemented and nonsupplemented gilts. In addition, glucose tolerance tests were conducted to determine the diabetogenic state of the dam. Results were collected from over 250 fetuses representing 23 litters analyzed at mid-pregnancy in gilts. Carcass composition of the dams following slaughter demonstration that the dietary protein supplement (casein at 1.3 g. kg−1 d−1 for 38 d) did not increase the maternal fat depots. Furthermore, supplemented animals displayed greater fetal: placental weight ratios (0.70 ± 0.03 vs. 0.60 ± 0.03; P ≤ 0.03). The analysis of the dams' glucose tolerance curves suggested a greater diabetogenic state existed in protein-supplemented gilts. The results suggest that dietary protein supplementation of pregnant gilts with apparently normal fat depots (average of 18.6 mm of backfat) may have a modest effect on fetal growth. Whether this would also apply to gilts displaying significantly leaner carcasses remains to be determined. Key words: Fetal growth, gilt, protein, glucose tolerance, nucleic acids
INFLUENCE OF GROWTH-HORMONE-RELEASING FACTOR AND (OR) THYROTROPIN-RELEASING FACTOR ON SOMATOTROPIN, PROLACTIN, TRIIODOTHYRONINE AND THYROXINE RELEASE IN GROWING PIGS
Authors: DUBREUIL P. , PELLETIER G. , PETITCLERC D. , LAPIERRE H. , COUTURE Y. , GAUDREAU P. , BRAZEAU P. , MORISSET J.
Published: March 2010

Three experiments were conducted to examine the influence of growth-hormone-releasing factor (GRF) and thyrotropin-releasing factor (TRF) on somatotropin (ST), triiodothyronine (T3), thyroxine (T4) and prolactin (PRL) release in gilts. Two experiments designed as 5 × 5 Latin squares were conducted to determine first the dose effect of human GRF (1–44)NH2 at 0, 3, 9, 27 and 81 μg kg−1 on serum GRF and ST concentrations, and second the effect of TRF at 0, 1,3,9 and 27 μg kg−1 on serum ST, T3, T4 and PRL. Areas under the curve (AUC) calculated for GRF increased (P < 0.001) proportionately to the dose: however, the ST response was maximized at an intermediary dose around 27 μg kg−1 (linear effect (P < 0.05) and quadratic effect (P < 0.01)). Injections of TRF did not influence ST AUC; however, there were significant (P < 0.05) linear and quadratic effects of TRF on T3, T4 and PRL AUC. In the third trial, to verify any interactions between the simultaneous administration of GRF and TRF, 12 Yorkshire purebred gilts averaging 137 ± 13 kg were randomly allotted, one by one, to six different treatments daily and this procedure was repeated for 3 consecutive days: A, control saline; B, porcine (p)GRF(1–29)NH2 (9 μg kg−); C, TRF (3 μg kg−1); D, TRF (9 μg kg−1); E, pGRF (9 μg kg−1) + TRF (3 μg kg−1); F, pGRF (9 μg kg−1) + TRF (9 μg kg−1)) according to a 2 × 3 factorial design. Each hypothalamic factor produced its own specific effect similar to those above without any evidence of interaction when injected simultaneously at 24-h intervals between each stimulation. In summary, a maximum ST response to s.c. GRF injection was seen at a dose close to 27 μg kg−1 and maximal PRL, T3 and T4 responses to s.c. TRF injection were obtained at a dose of 9 μg kg−1; TRF does not stimulate ST release and GRF and TRF injected simultaneously induced ST, PRL, T3 and T4 release without interacting with each other. Key words: Somatotropin, prolactin, thyroid hormones, growth hormone and thyrotropin-releasing factors, pigs
EFFECT OF TWO-MONTH TREATMENT WITH GROWTH HORMONE-RELEASING FACTOR ON GROWTH HORMONE RELEASE IN DAIRY COWS
Authors: LAPIERRE H. , PELLETIER G. , PETITCLERC D. , DUBREUIL P. , MORISSET J. , GAUDREAU P. , COUTURE Y. , BRAZEAU P.
Published: March 2010

Two experiments were conducted to examine the effect of a human growth hormone-releasing factor fragment (hGRF(1–29)NH2) on growth hormone (GH) secretion in lactating dairy cows. An initial study was conducted on 12 lactating dairy cows to determine the dose effect (5, 10 and 20 μg kg−1) of a subcutaneous (s.c.) injection of hGRF(1–29)NH2 on GH secretion. The three doses induced similar GH response, with peaks and areas under the curve (AUC) of 38.5, 41.2 and 38.0 ng mL−1, and 3496, 4112 and 4079 ng mL−1 min at 5, 10 and 20 μg kg−1, respectively. In a second study, the GH response after daily s.c. injections of saline (n = 8) or 10 μg kg−1 of hGRF(1–29)NH2 (n = 9) for 57 d was evaluated in dairy cows averaging 252 d in lactation. Blood samples were collected on d 1, 15, 29, 43 and 57 of treatment. On the last day of treatment, the GRF-induced GH peak was higher than on the first day, 46.8 vs. 25.2 ng mL−1, while the AUC was not different, 4010 vs. 2684 ng mL−1 min. Finally, to determine if the pituitary's ability to release GH was modified after 57 d of GRF treatment, the 17 cows were challenged with an intravenous injection of hGRF(1–29)NH2 (1 μg kg−1). Control cows had a lower peak (21.8 vs. 32.2 ng mL−1) but a similar AUC (2190 vs. 2579 ng mL−1 min) than GRF-treated cows. Hence, in lactating dairy cows, (1) s.c. administration of hGRF(1–29)NH2 induced a similar GH release with doses ranging from 5 to 20 μg kg−1 and (2) the GRF-induced GH peak was higher after 57 d of GRF treatment while the AUC was not different. Therefore, 2-mo GRF treatment of dairy cows during their two last month of lactation does not result in a decreased GH response to GRF. Key words: Growth hormone-releasing factor, growth hormone, cows (dairy)
EFFECTS OF DIETARY MOLYBDENUM ON PRODUCTIVITY AND METABOLIC PARAMETERS OF LACTATING EWES AND THEIR OFFSPRING
Authors: WITTENBERG K. M. , DEVLIN T. J.
Published: March 2010

A trial was undertaken to determine ewe lactation, lamb growth and metabolic responses to varying concentrations of molybdenum (Mo) in the diet of ewes. Twelve lactating ewes with twin lambs were assigned to one of three dietary treatments for the first 6 wk of lactation. Ewes were individually fed a corn silage-barley diet supplemented to contain 0.9 (0 Mo), 18.4 (20 Mo) or 40.7 (40 Mo) mg Mo kg−1 dry matter (DM) using ammonium molybdate [(NH4)6Mo7O24∙4H2O]. No feed was offered to lambs. Ewe milk yield and composition, ewe and lamb body weight and blood samples were obtained weekly. Two ewes assigned to 40 Mo and one ewe assigned to 20 Mo developed a condition that was corrected by thiamin administration during their fourth to fifth week on test. Diet did not influence (P > 0.05) milk yield or composition with the exception of milk Mo which increased (P < 0.05) for ewes fed Mo-supplemented rations. Dietary Mo concentration did not influence (P > 0.05) ewe plasma copper (Cu), trichloroacetic acid soluble plasma Cu or ceruloplasmin activity in ewes. Ewe plasma Mo concentrations increased (P < 0.05) 11- and 16-fold, respectively, for ewes fed 20 Mo and 40 Mo relative to those fed 0 Mo. Ewe liver Cu and Mo concentrations at the end of the trial tended (P < 0.10) to be greater for the Mo-supplemented diets. Lamb plasma and liver Cu concentration were not influenced by ewe diet. Milk Mo concentration did not influence (P > 0.05) lamb weight gain but did influence (P < 0.05) plasma Mo. Lamb age influenced (P < 0.05) plasma Mo levels which peaked when lambs were 2–3 wk old and declined thereafter. Key words: Ewe, lamb, lactation, growth, molybdenum, copper