bluuebunny/crossref_metadata_2025 huggingface dataset:
EFFECT OF LOCATION OF THE TEAT SUCKLED, BREED AND PARITY ON PIGLET GROWTH
Authors: DYCK G. W. , SWIERSTRA E. E. , MCKAY R. M. , MOUNT K.
Published: March 2010

The effect of location of the teat suckled on piglet growth was evaluated on 919 piglets in 111 litters from 20 Yorkshire (Y) and 17 Yorkshire × Lacombe (YL) sows over the 2nd to 4th parities. Analysis of covariance was used to adjust the data for the effect of birth weight and number of piglets born alive. Piglet weight at 35 d of age was correlated with birth weight (r = 0.606) and the number of piglets born alive (r = −0.256). A breed difference was observed only for piglet weight gain (adjusted for litter size) with Y piglets being lighter (P < 0.01) than YL piglets at both 21 (Y, 3.77 kg vs. YL, 4.10 kg) and 35 (Y, 6.84 kg vs. YL, 7.95 kg) days of age. Piglets suckling the three anterior teats were heavier (P < 0.01) at 21 and 35 d of age than piglets suckling the three to four posterior teats. The effect of teat location on piglet weight was apparent both as a main effect and through its interaction with sow breed and with parity. At 21 d of age the weight, adjusted for birth weight and number born alive, of Y and YL piglets suckling the anterior teats was similar (Y, 5.43 kg; YL, 5.55 kg) and greater (P < 0.05) than the weight of piglets suckling the posterior teats. For piglets suckling the posterior teats, the Y piglets were heavier (P < 0.05) than YL piglets (Y, 5.18 kg vs. YL, 4.78 kg). At 35 d of age, the Y piglets suckling the anterior teats were lighter (P < 0.05) than YL piglets (Y, 8.78 kg vs. YL, 9.35 kg), and heavier (P < 0.05) than piglets suckling the posterior teats. The weight of Y and YL piglets suckling the posterior teats was similar (Y, 8.33 kg; YL, 8.24 kg). For weight gain (adjusted for number born alive) the differences at 21 and 35 d of age were YLa (anterior teats)>Ya>YLp (posterior teats) = Yp, and YLa>Ya = YLp>Yp, respectively. The parity × teat location effect was an increase in the difference in average piglet weight between piglets suckling the anterior and posterior teats from 2nd to 4th parity (21 d, 0.33–0.65 kg, P = 0.137; 35 d, 0.39–1.17 kg, P = 0.085). For weight gain, these differences were significant (21 d, 0.31–0.75 kg, P = 0.017; 35 d, 0.43–1.26 kg, P = 0.007). These results indicate that the effect of location of the teat suckled on piglet weight is specific to the breed of dam and influenced by parity with piglets suckling the more anterior teats being heavier. Key words: Piglet weight, teat location, breed, parity
A DIFFERENCE IN WEIGHT REDUCES FIGHTING WHEN UNACQUAINTED NEWLY WEANED PIGS FIRST MEET
Authors: RUSHEN JEFFREY
Published: March 2010

The mixing of weaned pigs from different litters was observed so that the effect of a large difference in bodyweight on fighting could be examined. When 5- to 6-wk-old pigs met in pairs for 1 h, fights were longer and biting more frequent if the difference in weight between the pigs was small (< 0.5 kg) than if it was large (> 3.0 kg). In groups of four 5- to 6-wk-old pigs taken from different litters, fighting was more prolonged during 2 h after mixing if there was little weight variation in the group (coefficient of variation [Formula: see text]) than if there was large weight variation (coefficient of variation [Formula: see text]). When groups of four pigs were formed by taking one large and one small pig from each of two litters, the longest duration of fighting occurred between the two large pigs. Significantly less fighting occurred between the large and small pigs and between the two smaller pigs. Subordinate pigs were less likely to retaliate against the dominant pigs if the weight difference was large. It seemed that the presence of large pigs in the group inhibited fighting between equally matched smaller pigs. I suggest the common procedure of mixing pigs matched for weight exacerbates the initial fighting but how this affects growth rate will depend on the level of competition over food. Key words: Pigs, aggressive behavior, weight variation, mixing
USE OF SIB TESTING AS A SUPPLEMENT TO PROGENY TESTING TO IMPROVE THE GENETIC MERIT OF COMMERCIAL SEMEN IN DAIRY CATTLE
Authors: SMITH C. , RUANE J.
Published: March 2010

Groups of sibs, sisters to bulls being bred for progeny testing, can be produced by multiple ovulation and embryo transfer (MOET). Sib tests are complete at 3 yr of age, and progeny tests when bulls are about 5.5–6 yr of age. The merit of commercial semen could be increased by using the bulls with the highest estimated breeding values from both the sib test group and the progeny test group rather than only from the latter. With current selection rates (20%) among progeny-tested bulls for commercial use, current genetic trend (0.1 SD units per year) in bulls and with the equivalent of 3–7 full sisters per bull, the relative genetic superiority of semen from the combined groups could be from 1.10 to 1.20 times that from the progeny-tested group alone. Key words: Embryo transfer, sib testing, progeny testing, commercial semen
BLOOD BRANCHED-CHAIN AMINO AND α-KETO ACID CONCENTRATIONS AND NET EXCHANGE ACROSS THE PORTAL-DRAINED VISCERA AND HINDLIMB OF FED AND FASTED RUMINANTS
Authors: EARLY RICHARD J. , THOMPSON JAMES R. , CHRISTOPHERSON ROBERT J. , SEDGWICK GARY W.
Published: March 2010

In the first of two experiments, whole blood branched-chain amino acid (BCAA) and plasma branched-chain α-keto acid (BCKA) concentrations in jugular venous blood were determined in cattle and sheep before and during a 6-d fast. In cattle, concentrations of valine, isoleucine, α-ketoisovalerate (KIV) and α-ketomethylvalerate (KMV) remained unchanged whereas leucine and α-ketoisocaproate (KTC) increased (P < 0.05) during fasting. In sheep, only KIV and KMV remained unchanged whereas BCAA and KIC increased (P < 0.05) during fasting. In a second experiment on cattle chronically catheterized to measure BCAA and BCKA exchange across the portal-drained viscera (PDV) and hindlimb (HL), the PDV added and the HL removed BCAA from the blood of fed cattle. The opposite exchange occurred after a 6-d fast. Releases of BCKA from the PDV and HL in both fed and fasted states were small compared to BCAA exchanges. The data suggest that blood BCAA but not BCKA concentrations may respond differently to starvation in sheep versus cattle and that in cattle the PDV and HL do not release appreciable amounts of BCKA relative to the net movements of the BCAA. Key words: Portal-drained viscera, hind limb, branched-chain amino acids, branched-chain α-keto acids, fasting, ruminants
RELATION OF PREPUBERTAL SERUM STEROID PROFILES TO FIRST LACTATION MILK YIELD
Authors: MARCUS G. J. , McALLISTER A. J. , HACKETT A. J.
Published: March 2010

Correlation between prepubertal serum sex steroids and subsequent lactation performance was investigated with 98 Holstein, Ayrshire and crossbred heifers in the hope of finding a precise criterion for early selection. Blood samples were collected from the heifers at 100, 130, 160 and 190 d of age. Initially samples from the first 25 animals to provide a complete set of samples and completing their first lactation, were analyzed for progesterone, androstenedione, testosterone, estrone and estradiol. The relation between each steroid level at each age and first lactation milk yield was assessed by linear regression analysis. Day 130 androstenedione was found to be the variable most highly correlated with milk production. The day 130 steroid levels of all 98 heifers were then analyzed and relation of steroid level to first lactation milk yield was assessed by multiple linear regression procedures which treated breed as a dummy variable. Although the best model using the complete set of data accounted for 23% (R2) of the variation in milk production, 18% was due to breed alone. The reported usefulness of prepubertal steroid levels for predicting lactation performance was not confirmed. Key words: Prediction, lactation yield, steroids, heifers
INJECTABLE COPPER AND ZINC FOR GRAZING YEARLING STEERS
Authors: SANKOH F. A-R. , BOILA R. J.
Published: March 2010

Injectable Cu and Zn were evaluated as mineral supplements using 37 purebred Herefords (Group 1) and 23 Angus-Charolais-North Devon crosses (Group 2). The 60 steers were carried through a 113-d grazing phase. This was followed by a 79-d finishing phase for all steers of Group 1 and seven steers of Group 2. Treatments were combinations of the non-dosing (0Cu, 0Zn) and dosing (+Cu, +Zn) of steers with injectable Cu or Zn at the start of the grazing phase: (1) 0Cu, 0Zn; (2) +Cu, 0Zn; (3) 0Cu, +Zn; and (4) +Cu, +Zn. Injectables were the sole source of supplementary Cu and Zn during grazing and finishing phases. Means (SE) for Cu and Zn, respectively, in forages as milligrams per kilogram dry matter (DM) during the grazing phase were: grasses, 4.4 (0.17), 15.7 (0.46); alfalfa, 6.9 (0.18), 16.5 (1.49); and birdsfoot trefoil 5.0 (0.76), 15.0 (3.41). Injectable Cu did not influence (P > 0.05) body weight during the grazing phase. Body weight responses were lower (P < 0.05) for +Cu steers in the finishing phase, when dietary Cu was low, but steers could not be classified as Cu-deficient based on liver Cu. Liver Cu increased to means greater than 140 mg kg−1 DM in all steers, but was higher (P < 0.05) in +Cu steers during the grazing phase. Serum Cu varied widely during the grazing phase, but was higher (P < 0.05) for +Cu steers only on day 84 of the grazing phase. Neither liver Cu nor serum Cu was influenced (P > 0.05) by injectable Zn. Injectable Zn decreased growth rates in the latter part of the grazing phase but did not affect (P > 0.05) the body weight response during the finishing phase. The concentrations of Zn in liver and serum were not influenced (P > 0.05) by injectable Cu or Zn. Key words: Cattle, grazing, copper, zinc, injectable copper, injectable zinc
ALFALFA SUPPLEMENTATION OF CORNCOB DIETS FOR SHEEP: EFFECT OF RUMINAL OR POSTRUMINAL SUPPLY OF PROTEIN ON INTAKE, DIGESTIBILITY, DIGESTA, PASSAGE AND LIVEWEIGHT CHANGES
Authors: NDLOVU L. R. , BUCHANAN-SMITH J. G.
Published: March 2010

In trial 1, nine wethers (18 mo old; 50 kg liveweight) fitted with tubes inserted into the abomasum, were assigned to three 3 × 3 Latin squares to determine effects of supplementing a basal diet of ground corncobs with either alfalfa (30% of dry matter intake) or soy protein (60 g d−1 infused postruminally). In each period, following determination of effect of supplementation on intake, digestibility and digesta passage were determined, the latter by pulse dosing with chromium mordanted cell walls from cobs through the feed. Total dry matter intakes were increased (P < 0.05) from 780 g d−1 to 1143 g d−1 by the supplements with a corresponding improvement in liveweight gain, but there was no difference between supplements. Apparent digestibilities of dry matter, organic matter and cell wall were decreased (P < 0.05) by alfalfa supplementation but not by soy protein infusion; however, intakes of digestible energy were identical for both supplements. Relative to the basal diet, alfalfa increased digesta passage but not rumen fill whereas infusion of soy protein increased digesta fill in the rumen but not digesta passage. In trial 2, addition of soy protein directly to the basal diet resulted in an intake similar to alfalfa supplementation (1154 vs. 1262 g dry matter d−1 respectively). Fecal output, estimated using a single compartment model to describe digesta passage through the tract, yielded results similar to those obtained by total collection. Key words: Roughage (poor quality), abomasal infusion, chromium-mordanted cell walls, fecal output estimation
INFLUENCE OF DIETARY NUTRIENT DENSITY, LEVEL OF FEED INTAKE AND WEANING AGE ON YOUNG PIGS. I. PERFORMANCE AND BODY COMPOSITION
Authors: BALL R. O. , AHERNE F. X.
Published: March 2010

The performance and final body composition of 128 pigs weaned at either 3 or 4 wk of age and receiving either a normal density (ND) or high density (HD) diet ad libitum or restricted (85% of ad libitum) was determined over a 28-d period. Pigs weaned at 4 wk consumed more feed (P < 0.001) and grew faster (P < 0.005) than those weaned at 3 wk, but body weights at a similar age were not different. The HD diet supported greater gains (P < 0.01) and gain to feed (G:F) ratio (P < 0.005) than the ND diet. Restricting feed intake reduced gains (P < 0.001) and improved G:F ratio (P < 0.05). Interaction effects showed that performance of pigs weaned at 4 wk was less affected by nutrient density and feed restriction than that of pigs weaned at 3 wk of age. Pigs weaned at 4 wk had heavier carcasses at the end of the 28-d period than those weaned at 3 wk but there was no difference in percent water, fat or protein. Nutrient density did not affect body composition. However, restricted feeding increased percent water (P < 0.05), reduced percent fat (P < 0.05) and increased percent protein on a dry matter basis (P < 0.02). A significant interaction between weaning age and level of feed intake showed that restricting the intake of pigs weaned at 4 wk reduced fat deposition more than when intake was restricted for pigs weaned at 3 wk of age (P < 0.05). An interaction between diet, intake level and sex (P < 0.01) showed that even in young pigs, barrows tend to fatten more than gilts when energy intake is adequate and less when energy intake is restricted. Key words: Pigs, weaning, nutrient density, body composition, performance
INFLUENCE OF DIETARY NUTRIENT DENSITY, LEVEL OF FEED INTAKE AND WEANING AGE ON YOUNG PIGS. II. APPARENT NUTRIENT DIGESTIBILITY AND INCIDENCE AND SEVERITY OF DIARRHEA
Authors: BALL R. O. , AHERNE F. X.
Published: March 2010

One hundred and twenty-eight pigs were allotted to a factorial design involving two weaning ages (3 and 4 wk), two diets (normal density, ND, and high density, HD) and two levels of feed intake (ad libitum and restricted) and fed for 28 d postweaning. Feed restriction increased the digestibility of energy (P < 0.05). Apparent digestibility of energy and protein increased with time postweaning (P < 0.05). Pigs weaned at 4 wk of age had higher nutrient digestibilities than those weaned at 3 wk only in the second week postweaning (P < 0.05), showing that the digestive system of older pigs adapts faster. The apparent digestibility of the HD diet was not different from that of the ND diet. Diarrhea was more severe when pigs were weaned at 4 wk (P < 0.10), or when receiving the HD diet (P < 0.10), or when offered feed ad libitum (P < 0.10), showing that both volume of feed consumed and nutrient intake influence occurrence of diarrhea. Postweaning diarrhea was most severe (P < 0.05) and most frequent (P < 0.05) during the first week and declined thereafter. The rate of decline was fastest in older pigs (P < 0.05) with restricted feed intake (P < 0.05) and pigs receiving the ND diet (P < 0.05). There was a significant negative correlation (P < 0.05) between apparent energy and protein digestibility and incidence and severity of diarrhea during the first week postweaning. The results suggest that nutrient intake is more important in predisposing piglets to diarrhea than the volume of feed consumed. Key words: Pigs, weaning, digestibility, diarrhea
INFLUENCE OF FETAL NUMBERS AND HYPOPHYSECTOMY ON THE LENGTH OF GESTATION IN THE PIG
Authors: RANDALL G. C. B.
Published: March 2010

Parturition was not delayed in gilts carrying intact and hypophysectomized fetuses when four or more intact fetuses were present but its timing varied when fewer were present. In normal farrowings, gestation periods were longer for litters of two or three but not for litters of four. It is suggested that four fetuses are required for consistent delivery at the expected time. Key words: Gestation length, litter size, hypophysectomy
EFFECT OF TWO ACIDS AND FORMALIN IN CALVES MILK ON FEED CONSUMPTION AND PERFORMANCE
Authors: BUSH R. S. , NICHOLSON J. W. G.
Published: March 2010

Calves fed ad libitum whole milk plus formic acid, propionic acid or formalin consumed less than calves fed untreated milk and grew comparably slower. At weaning the control group was consuming up to 25% of their body weight in milk daily without significant scouring. Key words: Acidification, milk, calves
THE EFFECT OF A PROPIONATE FEED PRESERVATIVE IN DEOXYNTVALENOL (VOMITOXIN) CONTAINING CORN DIETS FED TO SWINE
Authors: FOSTER B. C. , TRENHOLM H. L. , FRIEND D. W. , HARTIN K. E. , THOMPSON B. K.
Published: March 2010

Diets containing deoxynivalenol (DON) prepared from Fusarium inoculated corn and Luprosil® NC, a propionate-based feed preservative, were offered to 34-kg barrows for 7 wk. The preservative improved overall performance of pigs fed the control or DON-containing diets, but did not appear to specifically reduce the adverse effects of DON. Key words: Deoxynivalenol, pigs, feed preservative, propionate, Fusarium graminearum
FACTORS INFLUENCING SEXUAL MATURATION, PUBERTY AND REPRODUCTIVE EFFICIENCY IN THE GILT
Authors: DYCK G. W.
Published: March 2010

Sexual development of the gilt involves the three distinct phases of sexual maturation, attainment of puberty, and pregnancy. Our knowledge of sexual maturation is at the stage of understanding the process, while puberty and pregnancy are at the stage of manipulation to improve efficiency. The developmental changes associated with sexual maturation are indicative of an orderly sequence of hormonal and anatomical changes that lead to puberty. This process is completed at an average age of 140 d (range > 80 d) and is followed by a "resting" period to the time of puberty. The reasons for variability in the rate of development are unknown and there is no easy method of determining when a gilt is sexually mature. In contrast, puberty is easily defined and occurs an average of 60 d after "completion" of prepubertal development (age range > 100 d). While it is not possible to substantially reduce age at puberty except by selection, puberty can be delayed by dietary intake restriction and by confinement housing (no movement or exposure to mature boars). When gilts are moved and exposed to mature boars, they will be in estrus in a short period of time provided that they have attained sexual maturity. Attempts to induce puberty with hormone injections at a younger age have not been effective because of the variability in age at sexual maturity. Research on the many facets of pregnancy has resulted in development of nutritional and mating management procedures to maximize ovulation rate, pregnancy rate and conception rate. However, there has been little change in litter size at birth, suggesting that the size of the uterus may ultimately limit litter size. Survival of the piglets born can be substantially improved by assisting the gilt during parturition and careiully managing the gilt and litter during lactation. The efficiency of management has been greatly increased by the use of prostaglandin analogues to control the time of parturition. Key words: Gilts, sexual maturation, puberty, litter size
PREFERENCE TESTS OF RAMP DESIGNS FOR YOUNG PIGS
Authors: PHILLIPS P. A. , THOMPSON B. K. , FRASER D.
Published: March 2010

Preference experiments were used to identify features of ramp design that influence the voluntary use of ramps by young pigs. In seven experiments, groups of pigs, aged 7–8 wk, were given free access to four different ramps simultaneously. The animals' behavior was monitored to identify the amount of time spent on the ramps and the number of pigs that failed to use specific designs. Slope, in the range of 20–32° from the horizontal, had a major influence on the pigs' behavior, with the shallower slopes attracting more use than steep ones. Pigs preferred ramps with angle-iron cleats (cross-laid on the ramps to provide foot-holds) spaced every 50 or 100 mm rather than 200 or 300 mm. Cleat height, in the range of 10–40 mm, had little effect. Pigs showed a slight preference for ramps with solid or open (wire mesh) side walls, compared to ramps partially enclosed by a railing. Reduced width (510 vs. 710 mm) was not a major impediment to ramp use, although the narrow ramps were used somewhat less, by a degree proportional to their smaller width. Level of illumination (up to 1200 lx) had no major effect. A staircase composed of 20 small steps was used at least as readily as a ramp of similar slope, but staircase designs with fewer, larger steps were not preferred. The results suggest that a ramp sloped at 20–24°, with cleats cross-laid every 50–100 mm, would provide a feasible design with good acceptance by young pigs, either for loading pigs or for two-level housing systems. Key words: Pigs, ramp design, choice experiments, behavior, loading, housing
ESTIMATION OF GENETIC TRENDS FOR CANADIAN STATION-TESTED BEEF BULLS
Authors: ROSE E. P. de , WILTON J. W.
Published: March 2010

Data collected from Canadian central test stations were used to obtain estimates of genetic progress for test station average daily gain (ADG-T), height at hooks (HH), ultrasonically measured backfat thickness midway between the 11th and 12th ribs (FAT) and scrotal circumference (SC). Where possible, records for preweaning average daily gain (ADG-W) from the Federal-Provincial Herd Record of Performance program were obtained for tested bulls. Estimated breeding values were regressed on year of birth to obtain estimates of genetic trend for each trait, for the six principal breeds enrolled in the testing program: Aberdeen Angus (AA), Charolais (CH), Hereford (HE), Limousin (LM), Shorthorn (SH) and Simmental (SM). Estimated trends were generally significant with the exception of those for the LM breed, and the trait of SC. For FAT, trends were generally positive for the exotic breeds, and negative for the British breeds. Significant positive trends were observed for HH, ADG-W and ADG-T for most breeds. Examples of estimated genetic trends, for the HE breed, were 0.0022 kg d−1 yr−1, 0.0023 kg d−1 yr−1, 0.090 cm yr−1 (NS), − 0.029 mm yr−1, and 0.009 cm yr−1 (NS), respectively, for ADG-W, ADG-T, HH, FAT and SC (NS = not significant). Most estimated trends were low, in the order of 0.1 to 0.5% of population mean per year. Key words: Genetic trend, central test stations, beef bulls
GROWTH AND FAT DEPOSITION CURVES IN SWINE
Authors: McKAY R. M. , GARNETT I.
Published: March 2010

Within-pig regressions of probed backfat thickness (BF) on liveweight (WT) and log10 of age (AGE) on log10 liveweight (LWT) were analyzed to: (1) assess the effects of farrowing season (spring, late summer-early fall), breed (Lacombe and Yorkshire), and sex (boar and gilt); and (2) if warranted, derive, test, and comment on alternative adjustment factors to the ROP adjustment factors currently in use. Results indicated that the interactions involving farrowing season, breed, and sex were significant for the regression parameters (slope, x− and y− intercept). Evaluation of adjustment factors led to the following observations: (1) a regression approach was more appropriate for adjusting age to a specific weight and for adjusting backfat probes at weights below the specific weight and (2) the ROP adjustment was more effective in adjusting backfat probes from weights above the specific weight. It was concluded that research on adjustment factors was required with season of the year, breed, and sex being considered. Any new adjustment factors should be flexible in order to accomodate shifts in the liveweight being adjusted to. Key words: Pigs, backfat, growth, breed, sex
THE ACCUMULATIVE EFFECT OF FINNSHEEP BREEDING IN CROSSBREEDING SCHEMES: REPRODUCTIVE PERFORMANCE
Authors: FAHMY MOHAMED H. , DUFOUR JACQUES J.
Published: March 2010

Reproductive performance and body weight were studied on 361 ewes, representing Finnsheep (F), DLS (a population of 1/2 Dorset, 1/4 Leicester, 1/4 Suffolk) and seven combinations ranging from 1/8 to 7/8 Finnsheep breeding. Conception rate in yearlings was 61.5% for DLS compared to 89.0% for F with the crosses being intermediate. Conception rate in older ewes was similar in the different genetic groups (avg. 94%). Ovulation rate and litter size at birth of DLS ewes were 1.72 and 1.44 lambs, which was less than half those of F ewes (3.51 and 2.86 lambs, respectively). Both traits increased progressively with an increase in F breeding in crosses and with advances in age. DLS ewes weaned 1.22 lambs compared to 2.03 lambs for F ewes and 1.84 lambs for 4/8 F ewes. The heaviest litters at weaning (31.7 kg) were raised by 4/8 F ewes, followed by 7/8 F (30.8 kg) while those raised by DLS ewes weighed 23.0 kg and F ewes 29.1 kg. Percentage of ova lost per ewe mated averaged 24% and ranged between 18% (DLS and 1/8 F) and 29% (6/8 F). About 3.6% of lambs were born dead and a further 13.8% died before weaning. Preweaning mortality rate was highest in F (22.9%) and lowest in 3/8 F (9.4%). Average kilograms of lambs weaned per ewe exposed was highest in 4/8 F (27.6 kg) followed by F (26.0 kg), whereas that of DLS was the lowest at 18.1 kg. The 4/8 F cross showed 25% heterosis in kg of lambs weaned per ewe exposed and 52.5% increase over DLS. Significant positive linear regressions were calculated for ovulation rate, litter size and preweaning mortality rate on proportion of Finnsheep breeding in crosses. The relation was quadratic for percent ova lost and lamb mortality at weaning. Yearling DLS females weighted 36 kg compared to 44 kg for F yearlings. However, at 5 yr of age DLS ewes weighed 62 kg, 5 kg heavier than F ewes. The heaviest ewes at all ages were the 4/8 F (45 kg at 1 yr, 65 kg at 5 yr). Key words: Reproduction, DLS sheep, Finnsheep, crossbreeding, heterosis, repeatabilities
EFFICIENCY OF FEED UTILIZATION BY THREE-BREED CROSS STEERS
Authors: McKAY R. M. , RAHNEFELD G. W.
Published: March 2010

Feed efficiencies, defined as feed-to-gain or weight ratios, were computed on 1046 steers reared between 1973 and 1978 at the Brandon Research Station. The progeny were out of 10 specific F1 crosses of dams mated to Charolais (C), Simmental (S), Limousin (L), and Chianina (Chi) bulls with none of the F1 dams being backcrossed. Dam crosses included the Hereford × Angus (HA) and crosses sired by C, S, and L bulls out of Hereford (H), Angus (A), and Shorthorn (N) dams. Feed-to-gain ratios were calculated on a live animal postweaning basis (for both a 140-d test and total liveweight gain from on-test to slaughter) and a carcass basis (hot carcass weight and rough or untrimmed lean, fat, and bone weights of combined cuts). The combined cuts were the rib, long loin (comprising the short loin and the sirloin butt), and round. In the live animal traits, the progeny from the 10 F1 dam crosses did not differ, but on a carcass basis, the progeny from the "exotic" crosses had better feed-to-gain ratios than the HA cross. Differences among the progeny of the "exotic" crosses included: C crosses < L crosses, "exotic" × A and "exotic" × N < "exotic" × H for hot carcass weight; "exotic" × N < "exotic" × H for rough weight of the combined cuts; S crosses < L crosses and "exotic" × N < "exotic" × A for fat and bone weights of the combined cuts; and "exotic" × N < "exotic" × H for fat weight of the combined cuts. There were no significant breed of dam's sire (maternal grandsire) × breed of dam's dam (maternal grand-dam) effects. Differences in breed of dam's sire were C < S for 140-d test, C < L for total liveweight gain, and S < L for bone weight of the combined cuts. Breed of dam's dam differences were N < (A = H) for fat weight of the combined cuts. Breed of terminal sire effects revealed that the progeny from the S and C breeds were similar for all measures of feed efficiency and the L and C breeds were only similar for feed efficiencies expressed on a carcass basis. Progeny from the Chi breed were comparable to the progeny from the C breed but not to the progeny from the S and L breeds in these traits. Key words: Beef cattle, breed crosses, steers, feed efficiency
GENETIC PARAMETERS FOR MATERNAL TRAITS IN BEEF CATTLE
Authors: TRUS D. , WILTON J. W.
Published: March 2010

Direct (D) and maternal (M) parameters for birth weight (BW), preweaning gain (WG) and calving ease (CE) were estimated for Angus (AN), Hereford (HE), Charolais (CH), Simmental (SM) and Shorthorn (SS). Data for the study were collected by Agriculture Canada from 1973 to 1983 for use in the National Sire Monitoring Program. Variances were estimated for each breed by a modified Method IV applied to a sire-maternal grandsire model with herd-year-seasons and age of dam × sex of calf as fixed effects. Genetic correlations (D/M) between D and M effects for WG in AN, HE, SS, CH and SM were −0.54, −0.42, −0.14, −0.26 and −0.45, respectively. Corresponding estimates of direct heritability for WG were 0.39, 0.30, 0.39, 0.27 and 0.43 and of maternal heritability 0.21, 0.27, 0.26, 0.16 and 0.20. Estimates for BW were similar to those for WG. Estimates of the D/M correlation for CE were −0.43, −0.15, −0.32, −0.74 and −0.27, of the direct heritability 0.28, 0.17, 0.19, 0.33 and 0.21, and of the maternal heritability 0.22, 0.13, 0.19, 0.23 and 0.27 for AN, HE, SS, CH and SM, respectively. Genetic trend and the introduction of new genetic lines are expected to have influenced parameter estimates. Due to negative D/M correlation estimates and moderate maternal heritabilities, selection for both the D and M components of maternal traits is advised. Key words: Variance, direct, maternal, heritability, genetic correlation, beef cattle
PROCEDURE FOR MEASURING RESTING AND SUMMIT METABOLISM IN SHEEP AND CALVES
Authors: YOUNG B. A. , WALKER V. A. , WHITMORE W. T.
Published: March 2010

Standard test procedures are described for measuring resting metabolism (RM) and cold-induced summit metabolism (SM) which involve immersion of the animal in a water bath and measurement of gas exchange by an open-circuit respiratory system. The method has been evaluated using neonatal lambs and calves and adult sheep. Conditions of measurement of RM and SM are defined in relation to water temperature, time after feeding, and animal activity. During each test, water and rectal temperatures and respiratory gas exchange were continuously measured while the animal was confined in 38 °C water to measure RM. The water temperature was then reduced to 18 °C to measure SM and rate of body cooling. Resistance to body cooling was measured as the time taken for rectal temperature to fall to 35 °C while the animal was immersed in 18 °C water. By the described procedures, measurement of RM, SM, and resistance to body cooling could be completed within 3 h without exposure of the animal to excessively low ambient temperatures that could damage superficial tissue or jeopardize the subsequent well-being of the animal. Furthermore, the measurements can be made on animals fed once daily without disrupting their daily feeding routine or having them out of their normal environment for an extended period. Key words: Calorimetry, resting metabolism, summit metabolism, body cooling, cold resistance
THE EFFECTS OF BARLEY PROCESSING ON NUTRIENT DIGESTION WITHIN THE GASTROINTESTINAL TRACT OF BEEF CATTLE FED MIXED DIETS
Authors: MANDELL I. B. , NICHOLSON H. H. , CHRISTISON G. I.
Published: March 2010

The effects of grain ammoniation (5% wt/wt) on the site and extent of nutrient digestion by cattle were evaluated by feeding diets containing 50% barley grain and 50% brome-alfalfa hay. Grain treatments consisted of: (1) rolled barley (15% moisture), (2) ammoniated, whole barley (15% moisture), (3) rolled barley (30% moisture) and (4) ammoniated, whole barley (30% moisture). Four 622-kg Hereford steers with ruminal and intestinal cannulas were used in a Latin square design. Acid detergent lignin and chromic oxide were used as digestibility markers. Because the overall conclusion about the effects of barley processing was not affected by the specific marker used, digestibility coefficients were calculated as the means obtained with the two markers. Forestomach digestion of organic matter from ammoniated, whole barley was approximately six percentage units lower (P < 0.05) than that from rolled barley. The small intestine compensated by increasing (P < 0.10) organic matter digestion of ammoniated, whole barley. Large intestinal and total tract digestion of organic matter was not affected by any dietary treatment. Total tract digestion of crude protein was depressed (P < 0.05) approximately five percentage units by ammoniation. This depression occurred principally within the small intestine. Ammoniation increased digestibility of neutral detergent fiber by approximately five percentage units, virtually all within the forestomach. Because palatability problems were encountered feeding ammoniated, whole barley, and because nutrient digestion was not improved in comparison to diets containing rolled barley, ammoniation of barley grain can not be recommended except as a method of grain preservation prior to physical processing. Key words: Ammoniation, barley, gastrointestinal tract, cattle, processing, markers
THE EFFECT OF CALCIUM SUPPLEMENTATION OF AN ALL-CONCENTRATE DIET FOR BEEF CATTLE
Authors: HIRONAKA R.
Published: March 2010

Eighty steer calves were divided equally into five groups and fed barley-based all-concentrate diets with 0, 0.3, 0.8, 1.1, and 1.4% added limestone (CaCO3). Steers fed the diet with no added limestone had lower rates of gain and required more feed per unit gain than those that were fed diets with added limestone. There was a trend (P < 0.10) toward lower feed intake per day as level of limestone in the diet increased. The incidence of animals walking with a stiff gait declined as the level of limestone increased. The steers were marketed as they reached a weight of about 475 kg. Carcass measurements and grades were not affected by limestone supplementation. Digestibility of the diets was determined using sheep as experimental animals. Protein and energy digestibility increased as level of limestone supplementation was increased. The source of calcium in the diet as well as the calcium to phosphorus ratio may influence feed intake and animal performance. Key words: Limestone, calcium, calcium to phosphorus ratio, beef, all-concentrate diet, liver abscess
PERFORMANCE AND CARCASS RESPONSES TO DIETARY INCLUSION OF RAW SOYBEANS (CV. MAPLE AMBER) BY BOARS FED AD LIBITUM FROM 30 TO 95 KILOGRAMS LIVEWEIGHT
Authors: CASTELL A. G. , CLIPLEF R. L.
Published: March 2010

Cull raw soybeans (SB), cv. Maple Amber, containing 17% oil and 36% crude protein (CP), were included as 0, 4.5, 9, 13.5, 18 and 22.5% of barley-based diets formulated to contain 16% CP. The mash diets were fed ad libitum to a total of 53 Landrace boars over the period from 30 to 95 kg average liveweight using a randomized block design with three replicates. Live performance responses to the increase in dietary SB content included a decline in overall growth rate (from 830 to 639 g d−1, P < 0.01) and efficiency of feed conversion (from 333 to 269 g gain per kg feed, P < 0.01). Post-kill measurements indicated an effect of dietary SB level on side weight (from 46 to 43% of carcass, P < 0.01), liver weight (from 24.8 to 28.2 g kg−1 warm carcass, P < 0.01) and areas of lean in the loin cross-section (from 31 to 26 cm2, P < 0.01) and ham face (from 137 to 121 cm2, P < 0.01) for pigs fed 0 and 22.5% SB diets, respectively. Analyses of samples of longissimus dorsi revealed a reduction in CP content (from 22.9 to 21.5%, P < 0.01) and increase in moisture content (from 74.4 to 75.4%, P < 0.05) for pigs fed the highest SB level compared to the control pigs. Iodine absorption numbers of the outer backfat layer increased, from 58 to 70 (P < 0.01), with the SB level fed. Sensory evaluation revealed a significant (P < 0.05) increase in incidence of off-flavor in loin roasts from boars fed diets containing more than 9% SB. The overall results suggested that a diet containing up to 5% SB would be unlikely to adversely affect performance or carcass merit of growing-finishing pigs. Key words: Pig, soybeans, live performance, carcass criteria, meat quality
THE INFLUENCE OF DIETARY ENERGY INTAKE DURING SUCCESSIVE LACTATIONS ON SOW PROLIFICACY
Authors: KIRKWOOD R. N. , MITARU B. N. , GOONERATNE A. D. , BLAIR R. , THACKER P. A.
Published: March 2010

From selection prior to the production of their first litters, 101 Yorkshire × Landrace sows were allocated to be ad libitum fed either a control (CE) or high energy diet (HE) during each of four successive lactations. Diets CE and HE supplied 13.7 and 15.6 MJ. DE kg−1, respectively. Sows were treated similarly during each gestation. Although HE sows tended to have a greater digestible energy intake, they lost more weight during each lactation (P < 0.05). Maternal weight gains between each farrowing decreased with successive parities (P < 0.05). Litter size at the second and subsequent farrowings was greater (P < 0.05) for the HE than CE sows. The overall mean litter size for the HE and CE sows was 10.1 and 9.3 piglets, respectively. A similar trend was noted for live births (9.7 vs. 8.9) and numbers weaned (8.3 vs. 7.9). There was no consistent effect of treatment on pig weights at birth or 21 d of lactation. No treatment or parity effects were evident for preweaning pig mortality. The weaning to conception interval was longer for HE sows in the first parity (14.9 vs. 11.1 d), but more CE sows were culled for reproductive problems. No treatment effects were noted for mean interval to conception, proportion mated within 8 d or subsequent farrowing rate in parities 2, 3 or 4. There was no effect of initial gilt breeding weight on the ability to produce up to four litters. It is concluded that low lactation digestible energy intake may limit subsequent litter size. Key words: Sow, lactation, nutrition, reproductive performance
PHENOTYPIC AND GENETIC PARAMETER ESTIMATES FOR GESTATION LENGTH, CALVING EASE AND BIRTH WEIGHT IN SIMMENTAL CATTLE
Authors: KEMP R. A. , WILTON J. W. , SCHAEFFER L. R.
Published: March 2010

Variance components, heritabilities and genetic and phenotypic correlations were estimated using progeny records of 73 sires on the Young Sire Proving Program (YSPP) of the Canadian Simmental Association. The YSPP was based on random mating of 58 test and 15 reference sires to cows in cooperating herds. Data were collected on several traits but the ones of interest in this study were gestation length (GL), calving ease (CE) and birth weight (BW). Variance and covariance components were estimated using Henderson's method 3. Heritability estimates were 0.24, 0.06 and 0.19 for GL, CE and BW, respectively. Genetic and phenotypic correlations were negative between GL and CE and CE and BW. Correlations between GL and BW were moderate and positive. Selection programs, utilizing large numbers of progeny per sire, would be effective but should incorporate the correlations between these traits. Key words: Heritabilities, genetic and phenotypic correlations, selection
PRODUCTION TRAITS OF RED AND WHITE RELATIVE TO BLACK AND WHITE HOLSTEINS
Authors: SULLIVAN P. G. , WILTON J. W. , DOORMAAL B. J. VAN
Published: March 2010

Canadian red and white (RW) and black and white (BW) Holsteins were compared for several production traits based on genetic evaluations of 32 RW and 883 BW bulls, and performance data of 4161 RW and 8691 BW cows. Differences (P < 0.05), favoring BW, were observed for milk and milk fat yield of cows, and for milk fat and milk protein yield evaluations of bulls. There was, however, a large genetic overlap between the populations for all traits studied. Pleiotropic effects associated with the color gene were not detected as being important. Phenotypic trends for milk yield, milk fat yield, and milk fat percent were significantly greater for BW than RW cows (P < 0.01). Genetic trends were greater for RW cows, though not significantly (P > 0.05). Key words: Dairy production, genetic trends, Holstein (red and white), Holstein (black and white)
REVERSIBLE RE-ENTRANT CANNULATION OF THE PAROTID DUCT IN SHEEP
Authors: CARTER RICHARD R. , GROVUM W. LARRY
Published: March 2010

A technique for reversible re-entrant cannulation of the parotid duct in sheep is described. A tube is inserted into the excretory duct via the papilla, is brought through the cheek, and connected to a three-way stop-cock positioned on the neck. A return tube from the stop-cock is passed through the cheek at a point forward and dorsal to the first tube. Sheep were maintained with such unilateral parotid cannulae for 3 mo or shorter periods. Saliva flow rates are comparable with values reported using other techniques. Removal of the tubing reverses the animal to its previous normal functioning state. This is an advantage over previously described procedures. Key words: Cannulation; parotid gland; parotid secretion; salivation; ruminants
LACK OF A PROTECTIVE EFFECT OF THIAMINE ON THE TOXICITY OF 3-NITROPROPANOL AND 3-NITROPROPIONIC ACID IN RATS
Authors: PASS M. A. , MAJAK W. , YOST G. S.
Published: March 2010

Acute and chronic nitrotoxin poisoning was induced by injecting 3-nitropropanol or 3-nitropropionic acid intraperitoneally into rats. Acute toxicity was characterized by rapid onset of collapse and coma. The chronic disease was characterized by decreased growth, food consumption and water intake. In more severely affected animals neurological signs of hind-leg paresis progressing to paralysis occurred. Administration of thiamine did not reduce the toxicity of the nitrotoxins in rats. Key words: Rat, toxicity, nitrotoxins, 3-nitropropanol, 3-nitropropionic acid, thiamine
ONTOGENY OF TEAT FIDELITY IN PIGS AND ITS RELATION TO COMPETITION AT SUCKLING
Authors: DE PASSILLÉ ANNE MARIE B. , RUSHEN JEFFREY , HARTSOCK THOMAS G.
Published: March 2010

The suckling behavior of 55 piglets from six litters was observed daily from birth to 10 d of age to describe the development of teat preference, teat fidelity and teat disputes and to relate these to weight gain. The percentage of piglets suckling from only one teat pair on each day increased from less than 5% on day 1 to 85% on day 10. By 3 d of age, the piglets had chosen their preferred teat pair, since 75% kept the same preferred teat pair between 3 and 10 d of age. The mean percent of nursings on the preferred teat pair increased from 50 to 86% during the first 3 d, and reached 95% on day 10. Teat disputes were most frequent on day 1 and missed nursings most frequent on day 2; frequency of both decreased as the piglets aged. On day 1, piglets that won most of their teat disputes suckled more frequently and had greater 3-d weight gains. After day 1, piglets that gained more weight were more consistent in the use of their preferred teat, pair, had fewer teat disputes and missed fewer nursings. Success at teat disputes was not related to weight gain after day 3. Typically, piglets suckled successfully; most of the variation in suckling behavior was due to the existence of "problem" pigs that were inconsistent in their use of teats, and were involved in teat disputes and missed nursings. Anterior teats were used more often. Piglets suckling from teats in the middle of the udder had a lower teat fidelity than those suckling at either end. Piglets suckling anterior teats gained more weight only between days 4 and 6. This effect disappeared once initial body weight and missed nursings were accounted for. We suggest that a high level of teat fidelity is an advantage to piglets because it reduces teat disputes and the chance of missing nursings. Key words: Piglet, suckling behavior, weight gain, teat order, fighting, teat disputes
BEHAVIORAL AND PHYSIOLOGICAL RESPONSES TO SPATIAL NOVELTY IN DAIRY COWS
Authors: KONDO S. , HURNIK J. F.
Published: March 2010

Thirty-two lactating Holstein cows were used in a study of excitability and agonistic behavior of dairy cattle. When cattle were moved from a familiar stall to an unfamiliar place, heart rate immediately increased on average from 83.2 to 107.8 (P < 0.01). The total distance of head movement in a novel environment varied considerably. The animal with the greatest head movement had a distance 6.6 times larger than the cow with the least head movement. Significant deviation from the mean values of agonistic interactions were found for 28 cows: of these 10 showed tendencies for physical attacks (P < 0.05), 5 for threats (P < 0.05), 6 for displacement of physical attacks (P < 0.05), and 7 showed significant tendencies for avoidance when threatened (P < 0.05). Both the instigator and victim cows that showed a higher proportion of the psychological form of agonistic behavior also tended to show a larger amount of head movement with less variation, lower increase in heart rate, and less change in norepinephrine concentration due to transfer. The results indicate that analyses of head movement patterns may be used for an assessment of excitability of cows. Key words: Cow, behavior, spatial novelty, head movement, excitability, temperament
EFFECTS OF GnRH ON LUTEINIZING HORMONE RELEASE AND ONSET OF CYCLIC OVARIAN ACTIVITY POSTPARTUM IN PELIBUEY EWES
Authors: GONZALEZ R. A. , MURPHY B. D.
Published: March 2010

Synthetic gonadotropin releasing hormone (GnRH) was administered to Pelibuey ewes to determine its effect on luteinizing hormone (LH) release and on cyclic ovarian activity during the first 3 – 4 wk postpartum. Two GnRH doses were given (10 and 100 μg) on days 4 and 5, 7 and 8, 14 and 15, and 21 and 22, after parturition, respectively. In three trials, 11, 8 and 7 ewes were used. For each trial 5, 3 and 2 ewes were used as controls, respectively; in trial 3, only the 100-μg dose was given once. Results from the three trials indicated that LH release always occurred after GnRH treatment, relative to the saline-treated controls. In trials 1 and 2, the 10-μg dose induced a higher (P < 0.001) LH release than the 100-μg dose; the LH release in response to the 100-μg dose in the three trials was of similar magnitude. Release of LH in response to both doses was lower (P < 0.05) during days 4 – 5 postpartum, than during the following 3 wk. Two types of luteal activity or steroidogenesis were observed in the GnRH-treated ewes, relative to the saline-treated ewes; (1) within 2 – 4 d after each GnRH injection small peaks of progesterone appeared, and (2) within 5 – 15 d after the last GnRH injection there were elevations of progesterone in peripheral plasma to concentrations and of durations characteristic of the luteal phase of the ovine estrous cycle. These results indicate that the pituitary of postpartum Pelibuey ewes regains the ability for maximal release of LH in response to GnRH challenge within 7 d postpartum. Further, treatment with GnRH induces earlier return to cyclic ovarian activity. Key words: Hair sheep, postpartum, GnRH, luteal activity