bluuebunny/crossref_metadata_2025 huggingface dataset:
IN SITU DEGRADATION OF FEED INGREDIENTS, FERMENTATION PATTERN AND MICROBIAL POPULATION AS INFLUENCED BY RUMINAL AMMONIA CONCENTRATION
Authors: SONG M. K. , KENNELLY J. J.
Published: March 2010

Effects of ruminal ammonia concentration on ruminal parameters and in situ degradation of feed ingredients were examined with nonlactating Holstein cows fed a complete mixed diet (70% barley silage and 30% concentrate mixture, dry matter (DM) basis). Ruminal ammonia concentrations of 16.3, 24.8 and 34.9 mg 100 mL−1 were achieved by continuous intraruminal infusions of NH4Cl. Ammonia concentrations in control animals were 11.2 mg 100 mL−1. Ruminal fluid pH decreased (P < 0.05) and blood urea N increased (P < 0.05) with NH4Cl infusion. NH4Cl infusion increased (P < 0.05) viable counts of proteolytic bacteria. Effective degradability of dry matter (EDDM) of concentrate ingredients and crude protein (EDCP) of soybean meal and fish meal were not affected by NH4Cl infusion. But EDCP of corn gluten meal was highest (P < 0.05) at ammonia concentration of 16.3 mg 100 mL−1 rumen fluid and EDDM and neutral detergent fiber (EDNDF) of barley silage decreased (P < 0.05) with increasing NH4Cl infusion. Results are interpreted to indicate that ruminal ammonia concentrations necessary for maximal bacterial growth may differ from concentrations required for maximal degradation of feedstuffs. However, decreased pH associated with NH4Cl infusion may have influenced the results obtained. Key words: Ammonia concentration, bacterial growth, in situ degradation
RYE AS A REPLACEMENT FOR WHEAT IN LAYING HEN DIETS
Authors: CAMPBELL G. L. , CAMPBELL L. D.
Published: March 2010

Two experiments were conducted in which rye replaced wheat as the cereal component of laying hen diets. In the first experiment laying hens were fed graded levels of Puma rye (0.0, 19.5, 39.0 and 78.0% of the diet) substituted for Glenlea wheat throughout a 280-d egg-production cycle. Rye-based diets supported comparable productive performance to wheat with respect to hen-day egg production, feed conversion, and body weight gain when the level of rye was 39.0% or less of the diet; however, performance declined at the higher rye level. For the second experiment Glenlea wheat was replaced by Gazelle rye (0.0, 23.3, 46.7 and 70.0% of the diet) when laying hens were in a latter phase of egg production, with the trial period commencing at 44 wk. Substitution of rye for wheat did not significantly affect egg production, feed consumption, egg weight, shell elasticity, or tibia ash at lower rye levels (< 46.7%), although there were indications of poorer performance at high rye levels (70.0%). Increasing the nutrient concentration of diets containing high levels of rye was not an effective means of alleviating poor performance induced by feeding rye in either experiment. Key words: Rye, laying hens
INFLUENCE OF DIETARY MANIPULATION ON THE DETRIMENTAL EFFECTS OF MOLD-CONTAMINATED BARLEY FED TO GROWING CHICKS
Authors: ROTTER R. G. , FROHLICH A. A. , MARQUARDT R. R.
Published: March 2010

The effects of feeding Penicillium cyclopium and Aspergillus flavus contaminated barley on Leghorn chicks were examined. Mycotoxin screening determined the mold-contaminated barley to be free of suspect toxins. This study examined the hypothesis that the effects of mold-contaminated barley are due to a deficiency of readily digestible nutrients, or some other factor. Chicks were fed diets containing either mold-free barley, a non-nutritive bulk (cellulose) plus mold-free barley, or a mold-contaminated barley (7% mold), in combination with low (2%) or high (10%) dietary tallow and supplemental starch (0 and 15%). High fat and starch supplementation both resulted in slightly higher weight gains for birds fed the mold-contaminated barley and cellulose containing diets, but the maximal improvement values were still more than 60 and 20%, respectively, lower than birds given a 6.7% tallow reference diet. Neither fat nor starch affected feed consumption. Birds fed the cellulose diet performed about 100% better than those given mold-contaminated barley, despite a theoretically lesser concentration of available nutrients in the former. Results of this study suggest the presence of some unidentified factor(s) in mold-contaminated. Key words: Mold-contaminated barley, mycotoxin, chick performance, starch, fat
NUTRITIONAL EVALUATION OF TRITICALE, WHEAT AND RYE GROWN IN ATLANTIC CANADA USING RATS
Authors: ANDERSON D. M. , ST. LAURENT A.-M. , FILLMORE ANN
Published: March 2010

Triticale (T) (cv. Trillium and Beauguelita), wheat (W) (cv. Belvedere) and rye (R) (cv. Kodiak) were evaluated in two growth trials with weanling Sprague-Dawley rats (10 per treatment) and in a metabolism trial with larger rats (body weight > 250 g). In trial 1, protein efficiency ratios (PER) were determined using 10% crude protein (CP) diets where the CP came exclusively from T-Beauguelita, T-Trillium, New Brunswick (NB) grown W-Belvedere, R-Kodiak (1984 or 1986 crop) or casein. Weight gain on both samples of R-Kodiak (avg. 64.4 g) was greater (P < 0.05) than on T-Beaguelita or W-Belvedere NB (45.5 and 38.3 g, respectively). The PER for casein (3.05) was higher than for R-Kodiak (avg. 1.90), T-Beaguelita (1.74), T-Trillium (1.66) or W-Belvedere NB (1.39). In trial 3, an additional sample of W-Belvedere grown in Nova Scotia (NS) was evaluated. Diets contained 93% test grain which supplied all of the CP and digestible energy (DE). Weight gain on T-Beaguelita (80.0 g) was greater than on R-Kodiak 1984 (62.2 g) while weight gain on W-Belvedere NS (43.2 g) was the lowest among all grains (P < 0.05). Apparent digestible energy (ADE) and apparent metabolizable energy (AME) of W-Belvedere NB (3453 and 3314 kcal kg−1, respectively) were higher than for W-Belvedere NS (3206 and 3129 kcal kg−1, respectively). ADE and AME of T-Beaguelita, T-Trillium and R-Kodiak 1984 were similar and lower in value than that of wheat. Triticale was well accepted by rats and was similar to rye and greater than the N.S. sample of wheat in nutritive value. Keys words: Triticale, rye, wheat, digestibility, protein efficiency ratio, PER, rat
MODIFICATION OF THE GLUCOSAMINE METHOD FOR THE QUANTIFICATION OF FUNGAL CONTAMINATION
Authors: MILLS P. A. , ROTTER R. G. , MARQUARDT R. R.
Published: March 2010

Modifications to the glucosamine (GlcN) analysis method for the quantification of fungal material in cereal grains are described. The modifications improve recovery of GlcN, increase reliability of the method and reduce analytical time. Key words: Glucosamine, fungal material, grain
GROWTH AND MATERNAL PERFORMANCE OF TWO-YEAR-OLD F1 AND RECIPROCAL BACKCROSS HEIFERS IN TWO ENVIRONMENTS
Authors: RAHNEFELD G. W. , McKAY R. M. , WEISS G. M. , FREDEEN H. T. , NEWMAN J. A. , LAWSON J. E. , BAILEY D. R. C.
Published: March 2010

Growth patterns and calf performance of 2-yr-old F1 and reciprocal backcross females were compared in two contrasting environments, semi-intensive management (Brandon, Man.) and extensive range management (Manyberries, Alta.). At Brandon, 621 heifers of Hereford × Angus (HA), Simmental × Shorthorn (SN), Charolais × Shorthorn (CN) and reciprocal backcrosses from Charolais × Hereford (CH), Charolais × Angus (CA), Charolais × Shorthorn (CN), Simmental × Hereford (SH), Simmental × Angus (SA), and Simmental × Shorthorn (SN) were evaluated. At Manyberries, 271 heifers of HA, SN, CN and reciprocals of SH, SA and SN were evaluated. They were bred to Limousin bulls. The HA heifers were the lightest at 14, 18, 24, 26 and 30 mo of age at both locations. Location differences for dam crosses in common ranged from 5% at 14 mo to 19% for 30 mo weight (Brandon > Manyberries). At all ages, the 3/4 C 1/4 N and the 3/4 S 1/4 N dam crosses were the heaviest at Brandon and Manyberries, respectively. Differences in weights at all ages between the CN and their reciprocal backcrosses were not significant at Brandon. The SN dams exceeded their reciprocal backcrosses in weight at all ages at Brandon (P < 0.01) but none of the differences were significant at Manyberries. Very few of the differences recorded for gestation length and birth weight at either location were significant. Progeny from HA dams were the lightest at birth and when significant differences existed for gestation length the longest were associated with the 3/4 "exotics." At both locations, progeny from HA dams were lightest and the progeny from the 3/4 "exotics" the heaviest at weaning. Females at Manyberries produced calves that were 3.3% heavier at weaning than those at Brandon. The highest weaning weight ratios were recorded for the 3/4 S 1/4 A, 3/4 S 1/4 N and SN dam crosses at both locations and these dam crosses were intermediate in weight at 30 mo. Total overall conception for breed crosses common to both locations for breeding at 14 and 26 mo was 77.0% vs. 75.8% and 82.1% vs. 79.5% for Brandon and Manyberries, respectively. Few differences were observed between dam crosses for conception rate. At Brandon, CX females required significantly more services per conception at 14 mo of age than SX females which reflected itself in lower conception rates. Compared with the SX females, the CX females had 11.8% lower conception to 1st service and 4% lower total conception. Calves born at Manyberries experienced greater calving difficulty but this was not reflected in higher calf mortality rates. Key words: Beef cattle, growth, preweaning traits, crossbreeding
GENETIC PARAMETERS FOR CALVING EASE IN AYRSHIRES
Authors: CUE R. I.
Published: March 2010

Estimates of genetic parameters of calving ease were obtained in Ayrshires. A restricted maximum likelihood model was used with the fixed effects of herd, month-season of calving, sex of calf and dam weight, and the random effect of sire (of calf). The heritability of the direct effect in heifers and in adult cows was approximately 2%, with a genetic correlation between the direct effect in heifers and in adult cows of close to 70%. Key words: Variance, heritability, calving ease, Ayrshire
EFFECTS OF TRANSPORT AND ELECTROLYTE SUPPLEMENTATION ON ION CONCENTRATIONS, CARCASS YIELD AND QUALITY IN BULLS
Authors: SCHAEFER A. L. , JONES S. D. M. , TONG A. K. W. , YOUNG B. A.
Published: March 2010

Two experiments were completed to: (1) identify predictive acid-base and electrolyte parameters that might be correlated with meat quality in marketed bulls; and (2) to determine whether bulls could be treated with either glucose or electrolyte drinks while in lairage to improve electrolyte balance and meat quality. In the first experiment, 29 crossbred yearling bulls averaging 499 ± 13.4 kg were exposed to either a minimal stress of no mixing and 3 km transport (N = 13) or a moderate stress of mixing, 6 h transport 24 h off feed in lairage, plus an additional 3 km transport immediately prior to slaughter (N = 16). Animals exposed to moderate stress displayed higher serum chloride values (137 mmol L−1) compared to pre treatment control (121 mmol L−1) or minimal stress values (118 mmol L−1) (P ≤ 0.01). The moderate stress group also displayed lower blood hydrogen ion concentrations (P < 0.05) and produced a high frequency of dark, firm and dry meat (9 out of 16 animals compared to 0 out of 13 in the control group). In the second experiment, 79 crossbred yearling bulls averaging 595 ± 6.5 kg were divided into treatment groups of either 19 or 20 animals each and subjected to mixing, handling and a 6-h transport period after which they were left in lairage for 18–20 h before slaughter. Treatment groups were: (1) no water during lairage; (2) water only; (3) electrolyte drink; or (4) a 5% glucose drink. Animals in exp. 2 given either water or no water displayed significantly higher serum sodium (P ≤ 0.01) and chloride ion (P ≤ 0.02) levels compared to animals offered an electrolyte or glucose drink. It was also found that the urine cation levels of animals offered no water or water only were significantly higher (P ≤ 0.05). In all animals, improved electrolyte balance coincided with improved meat quality traits and carcass yield. Key words: Electrolyte balance, transport stress, bulls, carcass quality
FAILURE OF AN INDUCED OVULATION DURING LACTATION TO IMPROVE SOW OR LITTER PERFORMANCE
Authors: KIRKWOOD R. N. , THACKER P. A.
Published: March 2010

To test the effects of elevated blood progesterone on sow and litter performance, sixty-four, mixed parity Yorkshire × Landrace sows were allocated to be induced to ovulate during lactation (n = 34) or to serve as controls (n = 30). Ovulation was induced by an intramuscular injection of 1000 IU PMSG at 10 d and 500 IU hCG at 13 d of lactation. During lactation, sows were fed ad libitum a diet formulated to provide 13.1 MJ DE kg−1 and 16% crude protein while their feed intakes were recorded weekly. Piglets were weaned at 28–31 d of age. Of the 34 sows administered gonadotrophins, 19(56%) ovulated as indicated by elevated serum progesterone concentrations measured on days 20 and 28 of lactation. There was no effect (P > 0.1) of ovulation during lactation on sow feed intake, weight loss or backfat loss (5.5 vs. 5.4 kg d−1; 20.3 vs. 15.4 kg and 2.3 vs. 1.7 mm for ovulating and control sows, respectively). Similarly, there was no effect (P > 0.1) of ovulation during lactation on piglet weight gain from 14 to 28 d of age (3.1 vs. 3.1 kg) or on piglet preweaning survival (91.0 vs. 94.5% for ovulating and control litters, respectively). Sows ovulating during lactation had longer weaning to estrus intervals (9.4 vs. 5.4 d; P < 0.01). It may be concluded that ovulation and an elevated serum progesterone concentration in the latter half of lactation will not influence sow or litter performance but may increase the interval between weaning and estrus. Key words: Sows, ovulation, lactation, appetite, reproduction
PUBERTAL DEVELOPMENT OF RAM LAMBS: BODY WEIGHT AND TESTICULAR SIZE MEASUREMENTS AS INDICES OF POSTPUBERTAL REPRODUCTIVE FUNCTION
Authors: YARNEY T. A. , SANFORD L. M. , PALMER W. M.
Published: March 2010

The relationship between the pattern of early testicular growth and postpubertal spermatogenic function and libido was investigated with 14 Suffolk rams born in March. Scrotal circumference and testicular diameter (TD) measurements were taken every 10 d between 30 and 190 d of age, and at 13 and 17 mo. Daily sperm output (DSO, sperm voided in urine) or semen quality, and libido were assessed at approximately 6, 13 and 17 mo of age. At 6 mo of age, rams with the larger testes had a greater DSO (r ≥ 0.77, P < 0.01) and mated estrual ewes more frequently (r ≥ 0.72, P < 0.01). Rams with larger testes at 13 mo had a greater DSO (r ≥ 0.74, P < 0.01), and those with larger testes at 17 mo ejaculated a higher percentage of motile spermatozoa (r ≥ 0.55, P < 0.05) and a greater number of spermatozoa (r = 0.61, P < 0.05; TD only). DSO at 13 mo was related to testicular size (r ≥ 0.54, P < 0.05) between 150 and 190 d of age. There were also correlations between the number of spermatozoa ejaculated at 17 mo and testicular size measurements (r ≥ 0.56, P < 0.05) taken between 170 and 190 d. However, ejaculation frequency (EF) at both 13 and 17 mo was not related to earlier testicular size measurements. Whereas testicular size and spermatogenic function of yearling Suffolk rams relate to testicular size measurements taken at about 6 mo of age, juvenile testicular size measurements correlate with EF only in the immediate postpubertal period. Key words: Sexual maturation, reproductive traits, interrelationships, ram
EVALUATION OF FOUR ON-FARM PROGESTERONE TEST KITS AS AN AID TO REPRODUCTIVE MANAGEMENT IN DAIRY COWS
Authors: RAJAMAHENDRAN R. , WONG B. , ROBINSON J. , SHELFORD J. A.
Published: March 2010

Four on-farm progesterone kits were evaluated for ease of use, color development and accuracy. No difference (P > 0.05) was found between kits in their ability to predict progesterone status but the accuracy of all kits varied with progesterone concentration. Tests were highly effective at low or high progesterone levels, but were of little predictive value for values between these extremes. Data suggest that on-farm progesterone tests are potentially useful management aids to confirm estrus, nonpregnancy and cyclicity. Key words: Progesterone, test kit, dairy cow
EFFECT OF RATE OF INTAKE ON RUMINAL RATE OF PASSAGE OF SMALL FORAGE PARTICLES
Authors: GIRARD V.
Published: March 2010

Circadian rate of intake and rumen parameters were studied in three rumen-fistulated steers fed long timothy hay once daily at 13:00 h. A sinusoidal model was used to relate rate of intake (INTAKE, kg h−1) (Y) to the rate of passage of small particles from the rumen. Parameters of the model Y = χ0 + χcos (time + θ) were the fitted mean intake at zero time (χ0), the fluctuation of intake (χ) and the phase. INTAKE was recorded seven times daily for the duration of the experiment. At the end of each week, fluctuations in individual INTAKE were regressed against recording hour over 24 h. The 7-wk experiment was divided into three periods. In the first period, fecal particles were examined. Small particles (< 0.8-mm diameter) represented 86 ± 4% of fecal NDF with no difference (P > 0.05) between grab samples of feces collected in the morning (07:00 h) and evening (19:00 h). In the second period consisting of 22 d, all rumen contents (54–123 kg) were removed at eight different times of the day, sampled and returned at 3-d intervals. Fluctuations in ruminal pool size of small particles (SMALL, kg) were regressed against sampling hour over 24 h. The fitted mean for SMALL was 3.97 ± 0.05 kg with a 0.44 ± 0.02 kg amplitude. On two occasions, chromium-labelled fecal particles were mixed with contents removed from, then returned to the rumen. Marker dilution curves were established up to 72 h after returning the contents to the rumen. Marker concentrations and estimates of SMALL over 48 h were used to compute fluctuations of the fractional rate of passage (kp). The third period served as a control for the INTAKE pattern. INTAKE fitted means, fluctuations and phases were not different (P > 0.05) betweeen periods, and it can be assumed that sequential rumen emptying did not affect the regularity of eating patterns or fluctuations of SMALL. SMALL and INTAKE fluctuations were negatively correlated (r = −0.98, P < 0.01). Largest SMALL occurred almost exactly at the lowest INTAKE, kp and SMALL fluctuations were also negatively correlated (r = −0.68 P < 0.01). Between 19:00 and 05:00 h SMALL increased and kp was less (P < 0.01) than the average rate (0.037 ± 0.004 h−1) during 72 h. When steers were resting or ruminating, small particles remained longer in the rumen than when steers were eating. This should be accounted for in protein degradability predictions. Key words: Particles, rumen, rate of passage, intake, cosinor
INFLUENCE OF ENERGY INTAKE ON DEVELOPMENT OF BROILER BREEDER PULLETS
Authors: BENNETT C. D. , LEESON S.
Published: March 2010

One hundred and two broiler breeder pullets were reared from 10 wk of age on one of three diets formulated to contain 15% CP and provide 10.67, 11.72, or 12.89 MJ ME kg−1. All birds received the same daily feed allotment. At 20 wk of age, the pullets were light-stimulated and nine birds per treatment were slaughtered for carcass analysis. The remaining birds were slaughtered for carcass analysis at the time that they laid their first egg. Twelve birds from each treatment were blood sampled from 10–25.5 wk of age and plasma luteinizing hormone levels determined. While all birds had similar ages at first egg, birds given the high energy diet grew faster and had more fat, protein and fat-free mass in the body at first egg relative to birds consuming the least amount of energy. Birds fed the high energy diet also displayed a higher percentage of fat and lower percentage of protein at first egg than did the birds fed the low energy diet. Coefficients of variation for weight of protein and fat-free mass at first egg were 9.1 and 7.9%, respectively, compared to 24.4% for grams of fat at first egg; protein and fat-free masses appeared to be relatively constant at first egg. Linear regressions suggested a strong relationship between body composition and body weight both at 20 wk of age and first egg. Plasma luteinizing hormone levels were unaffected by diet. Key words: Broiler breeder, body composition, body weight, sexual maturity, energy intake
BLOOD COMPOSITION IN HEREFORD AND ANGUS BULLS FROM LINES SELECTED FOR RAPID GROWTH ON HIGH-ENERGY OR LOW-ENERGY DIETS
Authors: BAILEY C. B. , LAWSON J. E. , MEARS G. J.
Published: March 2010

Angus and Hereford bull calves were obtained from lines of cattle selected for 18 yr for rapid post-weaning gain on high-energy or low-energy diets. After weaning they were given a common diet consisting of 70% barley-based concentrate and 30% roughage. Bulls whose ancestors were selected on the high-energy diet had lower levels of cholesterol and albumin in the blood than bulls whose ancestors were selected on the low-energy diet. Blood insulin, growth hormone and energy substrates were not affected by differences in the nature of the selection diets and this accords with absence of effect of selection diet on rate, efficiency or composition of gain. The significance of the selection effects on cholesterol and albumin levels in blood is unknown. Key words: Angus, Hereford, bulls, blood, composition, selection
ETHIONINE SUPPLEMENTATION OF BARLEY DIETS CONTAINING LENTILS (Lens culinaris) OR SOYBEAN MEAL: LIVE PERFORMANCE AND CARCASS RESPONSES BY GILTS FED AD LIBITUM
Authors: CASTELL A. G. , CLIPLEF R. L.
Published: March 2010

Barley-based diets, containing 13.3% soybean meal or 40.0% lentils, were fed over the period from 25 to 90 + kg liveweight. Supplementation with 0.1% DL-methionine improved performance and carcass characteristics of lentil-fed pigs to the level of those receiving soybean meal diets. Key words: Pig, barley, lentils, methionine, carcass
SOCIAL STRESS AND DOMINANCE AMONG GROUP MEMBERS AFTER MIXING BEEF COWS
Authors: MENCH J. A. , SWANSON J. C. , STRICKLIN W. R.
Published: March 2010

Three groups of 10 spring-calving Angus and Hereford purebred and crossbred cows were placed in drylot paddocks from mid-November until calving to determine the influence of mixing mature beef cows from two different sources on social behavior and stress. Two Angus cows from an outside herd (alien cows) were placed in each paddock, and eight cows selected from the resident herd were added 1 d later. Agonistic behavior was recorded during a total of 21 30-min observation sessions over a period of 13 wk. Blood samples were drawn on days 2, 28 and 84 after penning and analyzed for cortisol, glucose and differential leucocyte counts. Breed-origin influenced (P < 0.01) social dominance values, which averaged 49.8, 48.7, 40.1 and 35.0 for crossbred, resident Angus, Hereford and alien Angus cows, respectively. Alien Angus received the most aggression during the first observation period (0–36 d after mixing) and initiated less aggression throughout the study as compared to resident cows. Physiological measures did not differ due to breed-origin, group or sample day, but there was a significant sample day × breed-origin effect for cortisol (P < 0.01), with levels for the cows from the most socially subordinate groups, alien Angus and Hereford, increasing over the sample days. The increasing cortisol values may have indicated cumulative social stress on the social subordinates within the groups. Other physiological variables, however, did not show a similar trend. We conclude that when small numbers of cattle from different sources are mixed the aliens are at a social disadvantage, and we speculate that under some conditions social stress on aliens and(or) subordinates may be additive over time. Key words: Cattle (beef), agonistic behavior, social stress, mixing, cortisol, immunocompetence
BEHAVIOR OF PERIPARTURIENT DAIRY COWS AND THEIR CALVES
Authors: HOUWING H. , HURNIK J. F. , LEWIS N. J.
Published: March 2010

The pre- and postparturient behavior of 14 Canadian Holstein cows and 16 heifers, and the neonatal behavior of their 31 calves were analyzed. In the 12 h before parturition an increase in semilateral recumbency and a decrease in standing and ruminating were noted. Twenty-four births, 13 by cows (87%) and 11 by heifers (69%), took place with the dam recumbent. Dams requiring assistance remained recumbent longer (4 min vs. 37 min). However, the management practice of placing the calf in front of the dam following an assisted delivery may have contributed to the longer period of recumbency. Cows stood sooner (14 min) than heifers (37 min) following delivery. During the first 3 h postpartum the dam spent 43% of the time licking her calf. Calves were observed in semilateral recumbency 65% of the time and lateral recumbency 14% of the time, interspersed with standing and suckling. Female calves and calves born to heifers stood and suckled earlier. This may have been related to the lower body weight of these calves compared to male calves and calves born to cows. After removal of the calves (10.1 ± 4.1 h), the dams' maintenance behavior, including lateral recumbency, ruminating, eating and self-licking, increased in frequency. Key words: Dairy cow, parturition, behavior
GROWTH EFFICIENCY IN MICE SELECTED FOR INCREASED BODY WEIGHT
Authors: SALMON R. KEITH , BAILEY DAVID R. C. , WEINGARDT RAY , BERG ROY T.
Published: March 2010

To elucidate the effect of selection for increased growth upon growth efficiency (gain:feed), growth and feed consumption patterns were studied in three lines of mice. Two of the mouse lines (H lines) had been selected for high 42-d body weight while the third was an unselected foundation (FP) population. The two H lines differed in population size and were designated as the high-large (HL) and high-small (HS) lines. Logistic growth curve analysis revealed that, in terms of growth rate and mature body size, the three lines could be ranked as HL > HS > FP. When considered relative to age, the feed consumption of the H line mice exceeded that of FP mice. When growth efficiency was considered relative to body weight, HL mice exhibited a significantly higher efficiency than either HS or FP mice. However, when considered relative to degree of maturity (body weight/asymptotic body weight), differences in growth efficiency were greatly reduced. This effect of maturity upon growth efficiency is compatible with the previous suggestion (Taylor and Murray 1987) that many growth-related variables are strongly associated with an animal's "target" mature body weight. A corollary of this suggestion is that much of the well characterized selection responses, of "high-growth" selection lines, may be accounted for by genetic differences in a factor associated with the elevation of their target mature body weight. Key words: Growth-selected mice, growth efficiency, mature body weight
HERITABILITY OF TEAT NUMBER IN SWINE
Authors: McKAY R. M. , RAHNEFELD G. W.
Published: March 2010

Heritabilities were estimated for teat number in nine populations of swine over two time periods. From 1962 to 1974 the populations included Lacombe, Yorkshire, and Lacombe × Yorkshire. In this data set, only total teat number was recorded. From 1982 to 1988 three purebred populations (Landrace, Yorkshire, and Hampshire) and three crossbred populations (Landrace-Yorkshire rotation, Landrace × Yorkshire, and Landrace × Hampshire) were represented and total teat number and the number of teats anterior and posterior to the navel were recorded. Heritabilities for total teat number were greater in the 1982–1988 data (ranging from 0.27 to 0.47) than in the 1962–1974 data (ranging from 0.20 to 0.32). The heritability of posterior teat numbers (ranging from 0.08 to 0.39) was generally larger than the heritability of anterior teat numbers (ranging from 0.03 to 0.21) and both were considerably less than the heritability of total teat number. Genetic and phenotypic correlations were calculated for the relationships between anterior and posterior teat numbers (AP), anterior and total teat numbers (AT), and posterior and total teat numbers (PT). The relative magnitudes of the genetic and phenotypic correlations with respect to AP, AT, and PT revealed that selection for increased total teat number would increase the number of anterior and posterior teats. However, the larger genetic correlations for PT relative to AT would lead to a greater increase in posterior teat number than anterior teat number. Key words: Pigs, teat number, heritability, genetic correlation, phenotypic correlation
FEED INTAKE OF GROWING BULLS DURING SEVERE WINTERS
Authors: CHRISTISON G. I. , NICHOLSON H. H. , CYMBALUK N. F.
Published: March 2010

Dry matter (DM) intake was recorded daily for 12 pens of young bulls for 140 d in each of eight winters. Monthly means for DM intake ranged from 1.94 to 2.62 kg 100 kg−1 body weight (BW) and average daily gains (ADG) ranged from 1.15 to 1.46 kg d−1. Stepwise multi-variable procedures indicated that days on test (age) accounted for most of the variation in feed intake (partial R2 = 0.380). Climatic variables provided little additional explanation. Dry matter intake was scaled to 100 kg BW to minimize the influence of increasing weight with time. The multi-variable model which described weight-scaled DM intake included age (partial R2 = 0.509) and daily temperature (partial R2 = 0.013). Weight-scaled intake declined with age; the temperature effect represented a 2% increase in response to a drop in temperature from 0 to −15 °C. Equivalent increases in weight-scaled DM intake of 4.5 and 6.5%, respectively, were calculated by simple linear regressions based on daily or monthly temperature and intake values. Temperatures below −20 °C had no greater effect on intake or weight-scaled intake than those in the −10 to −20 °C range. It was also concluded that silage was unlikely to reduce DM intake at low temperatures and that European breeds of bulls had a twofold greater (P < 0.01) increase in weight-scaled DM intake in response to cold than did British breeds. Key words: Cattle, cold, environment, feed intake, winter
AGE, WEIGHT, BACKFAT AND TIME OF MATING EFFECTS ON PERFORMANCE OF GILTS
Authors: YOUNG L. G. , KING G. J. , WALTON J. S. , McMILLAN I. , KLEVORICK M.
Published: March 2010

An experiment was conducted involving 429 gilts that were managed to stimulate estrus after 140 d of age, bred at first, second or third observed estrus and to study factors relating to estrus and reproductive performance to weaning of the first litter. The average at first estrus followed by the coefficient of variation (%) in parentheses were: age 167.2 d (11.8); weight 106.8 kg (15.5); backfat 19.1 mm (17.8); backfat/weight 0.18 (16.2) and weight/age 0.64 (11.5). Sixty-two and one-half percent of the gilts exhibiting estrus did so between 140 and 170 d of age. Fifty-eight percent of the gilts exhibited estrus prior to 180 d of age and were less than 110 kg liveweight. There were relatively low correlations between indices of growth rate and fatness with age at first estrus. Reproductive performance was not enhanced by delaying breeding to second or third estrus after puberty. Key words: Pigs, reproduction, sexual maturity, age, weight, backfat
EFFECT OF α-TOCOPHEROL SUPPLEMENTATION TO DAIRY COWS ON MILK AND PLASMA α-TOCOPHEROL CONCENTRATIONS AND ON SPONTANEOUS OXIDIZED FLAVOR IN MILK
Authors: ST-LAURENT ANNE-MARIE , NICHOLSON J.W.G. , HIDIROGLOU M. , SNODDON M.
Published: March 2010

An α-tocopherol supplementation study was conducted with 12 Holstein cows, assigned to one of three dietary α-tocopherol levels, 0, 700, and 3000 IU cow−1 d−1, as dl-α-tocopheryl acetate. Cows were fed a basal diet of alfalfa silage and a barley-corn-soybean meal grain mix. The study consisted of a pretreatment (wk 0), a treatment (wk 1 to 5) and a posttreatment phase (wk 6 and 7). Peak milk α-tocopherol levels were observed at wk 1 for the 700 IU group and at wk 2 (P < 0.05) for the 3000 IU group. During wk 2 to 5 milk α-tocopherol concentrations were highest for the 3000 IU group and peaked at 22.0 μg g−1 lipid; plasma α-tocopherol levels increased by 0.7 and 1.3 μg mL−1 for the 700 and 3000 IU groups. By the end of the posttreatment phase, milk α-tocopherol concentrations had returned to wk 0 levels. A field study was conducted of four herds (142 cows) with a chronic spontaneous oxidized flavor (SOF) milk problem. The herds were fed α-tocopherol at 0, 700 and 3000 IU cow−1 d−1 in a changeover design of 2-wk periods followed by access to spring pasture for 4-wk. Milk flavor improved when higher levels of α-tocopherol were fed and SOF was minimal when pasture was grazed. The percentage of cows in the herds producing SOF milk was 68, 61, 56, and 8 for the 0, 700 and 3000 IU d−1 treatments and pasture, respectively. α-Tocopherol levels were highest (P < 0.05) in milk for the 700 IU d−1 level of feeding and in plasma (P < 0.05) when pasture was consumed. Milk and plasma α-tocopherol levels did not correlate well with improved flavor scores. Key words: Spontaneous oxidation, milk, α-tocopherol, dairy cow, flavor, vitamin E
USE OF FORMALDEHYDE TO REGULATE DIGESTION OF BARLEY STARCH
Authors: McALLISTER T. A. , CHENG K.-J. , RODE L. M. , BUCHANAN-SMITH J. G.
Published: March 2010

This study was conducted to determine the effect of formaldehyde treatment of barley on the rate of microbial starch digestion. Ground barley was left untreated (UB) or treated with 0.5% formaldehyde (TB) and incubated in vials with an inoculum consisting of a homogenate of rumen contents and Bryant's anaerobic media (1:1). Separate vials were analyzed for starch, ammonia, pH and volatile fatty acids (VFA) after 0, 4, 8, 12, 18, 24, 36 and 48 h. The digestion of starch was lower (P < 0.05) in TB than in UB between 4 and 24 h. Accumulation of NH3 was lower and pH was higher in TB vials (P < 0.05) than in UB vials. VFA production and fermentation efficiency were lower (P < 0.05) in TB than in UB. Formaldehyde treatment of barley reduced (P < 0.05) the production of propionate and enhanced (P < 0.05) the production of butyrate in comparison with UB. Examination by scanning electron microscopy (SEM) showed that the initial colonization of TB was inhibited in comparison with that of UB. The distinct shape of the endosperm cells of TB (12 h) were readily recognizable, but the endosperm cells of UB (12 h) were not readily distinguishable. SEM of TB (24 h) showed that the protein matrix of the endosperm cell is resistant to microbial digestion. The formaldehyde-induced reduction in starch digestion appears to result from the protein matrix inhibiting the access of bacteria to underlying starch granules. Key words: Starch, rumen bacteria, formaldehyde, barley
EFFECTS OF DIETARY CALCIUM, CORN PARTICLE SIZE, FORAGE SOURCE AND CATTLE TYPE ON SITE AND EXTENT OF DIGESTION IN STEERS
Authors: BURGHARDI S. R. , GARRETT J. E. , GOODRICH R. D. , MEISKE J. C.
Published: March 2010

Effects of dietary Ca on site and extent of digestion were evaluated using four Holstein (dairy) and four Angus × Hereford (beef) steers fitted with T-type cannulas at both the proximal duodenum and distal ileum of the small intestine. In trial 1, steers were fed diets based on corn (85% of diet dry matter (DM) and corn silage (15% of diet DM) at 2.1% of body weight. Treatments were dairy or beef type cattle, cracked (2.4 mm) or whole (6.0 mm) corn grain and 0.31 or 0.62% of diet DM as Ca from CaCO3 in a 2 × 2 × 2 factorial design. Cattle type and dietary Ca did not affect (P > 0.05) site or extent of organic matter (OM) or starch digestion. Steers fed cracked corn digested more (P < 0.05) OM and starch in the rumen than steers fed whole corn. Fecal pH was higher (P < 0.05) in steers fed high Ca diets. In trial 2, steers were fed diets based on ground corn (80% of diet DM) and chopped hay (20% of diet DM) at 1.8% of body weight. Treatments were dairy or beef type, alfalfa or smooth bromegrass hay and 0.34 or 0.61% of diet DM as Ca from CaCO3 in a 2 × 2 × 2 factorial design. Cattle type and dietary Ca levels did not affect (P > 0.05) site or extent of OM or starch digestion. Steers fed alfalfa digested more (P < 0.05) dietary starch in the rumen than those fed smooth bromegrass. Digesta collected from the distal ileum of steers fed alfalfa had a higher pH than that from steers fed smooth bromegrass. The higher dietary Ca resulted in higher (P < 0.05) fecal pH. Key words: Calcium, particle size, starch, forage source, cattle
THE INFLUENCE OF DIFFERENT DIETARY FATS ON THE REPRODUCTIVE PERFORMANCE OF TURKEY HENS
Authors: VILCHEZ C. , TOUCHBURN S. P. , CHAVEZ E. R. , CHAN C. W.
Published: March 2010

Turkey breeder hens of the Quebec line were fed diets with no added fat, 3.5% animal-vegetable fat blend (A-V fat), or 3.5% fat provided by 4.4% dry fat product (DF), from 30 to 49 wk of age. The addition of A-V fat and DF to the breeder diets significantly (P < 0.05) reduced embryonic mortality between 8 and 28 d of incubation but had no effect on other reproductive parameters. Feeding diets with 0 or 5% A-V fat in a prebreeder diet from 21 to 28 wk of age in another experiment led to a detectable decrease in subsequent egg production. Those diets were followed by breeder diets with either no added fat, 5% A-V fat, 5% corn oil, or 5% olive oil from 28 to 48 wk of age. Hens fed no added dietary fat exhibited significantly higher fertility while those fed 5% corn oil laid the heaviest eggs. Hens fed 5% olive oil exhibited significantly higher embryo livability from 8 to 28 d of incubation and the highest hatchability of fertile eggs. Fatty acid compositions of plasma and yolk lipids were affected by the dietary fat composition. Key words: Turkey hens, dietary fat, reproduction, fatty acid
DETERMINATION OF CRYSTALLINITY OF CARBOHYDRATES BY 13C CROSS POLARIZATION/MAGIC ANGLE SPINNING NMR WITH APPLICATIONS TO THE NUTRITIVE VALUE OF FORAGES
Authors: CYR NATSUKO , ELOFSON R. M. , MATHISON G. W.
Published: March 2010

An NMR technique using solid samples is presented. The relative "crystallinity" of carbohydrates is estimated by the use of a 20 ms delayed contact pulse sequence. There was good agreement between the crystallinity of cellulose determined by the NMR procedure and that estimated by using an acid hydrolysis procedure. The "crystallinity index" (crystallinity relative to that of cellulose powder at 100) of timothy stems increased from seven for samples cut on 30 June to 16 for those cut on 15 July. Mature-weathered timothy stems which were collected in the spring had a "crystallinity index" of 20. The carbohydrate crystallinity index increased from 10 in alfalfa-grass hay to 49 in a sample of fecal fiber from a steer fed this hay indicating that noncrystalline carbohydrate is preferentially digested in the animal. Treatment of fecal fiber with ammonia decreased the crystallinity index. It was concluded that the NMR technique can provide useful information concerning the nature of the carbohydrates in forages. Key words: I3C CP/MAS NMR, delayed contact pulse sequence, crystallinity, carbohydrates
VARIATION IN MEAT QUALITY AT THREE SITES ALONG THE LENGTH OF THE BEEF LONGISSIMUS MUSCLE
Authors: GARIÉPY C. , JONES S. D. M. , ROBERTSON W. M.
Published: March 2010

Variation in meat quality parameters (pH, color, shear force, expressible juice, drip loss) for the longissimus muscle at three sites (site 1 = 4–7th ribs, site 2 = 8–12th ribs, site 3 = 13th rib - 5th lumbar vertebra) was investigated in the right carcass sides from 80 steers. Muscle pH was similar for all three sites at 45 min and at 24 h postmortem. At 6 d, muscle pH was higher (P < 0.05) at site 1 than site 3. Visually assessed color scores were similar (P > 0.05) for all three sites. Minor differences were found for expressible juice and drip loss across the three sites. It was concluded that apart from shear force, quality variation at the three sites along the longissimus muscle was minor. Key words: Beef, longissimus, meat quality variation
EFFECT OF EXOGENOUS GROWTH HORMONE DURING THE FOLLICULAR PHASE ON hCG BINDING BY PORCINE LUTEAL TISSUE
Authors: KIRKWOOD R. N. , THACKER P. A. , GUEDO B. L. , LAARVELD B.
Published: March 2010

From 14 d after puberty, 37 Yorkshire Landrace gilts received nine daily injections of porcine growth hormone (GH) or vehicle. Gilts were killed 10 d after the onset of their second estrus and their ovaries recovered. Treatment with GH resulted in an increase (P < 0.05) in the hCG binding capacity of the corpora lutea (0.17 vs. 0.11 nmol L−1 mg−1 protein). These data provide a possible mechanism whereby GH may influence ovarian function. Key words: Gilts, hCG binding, growth hormone
COPPER ACCUMULATION IN THE LIVER OF SHEEP AND CATTLE FED DIETS SUPPLEMENTED WITH COPPER SULFATE OR COPPER CHLORIDE
Authors: IVAN M. , PROULX J. G. , MORALES R. , CODAGNONE H. C. V. , DAYRELL M. DE S.
Published: March 2010

Six groups of 12 pregnant cows were fed barley or grass silage with or without copper sulfate or copper chloride supplements (16 or 14 mg copper kg−1 dry matter (DM)). In addition, five groups of 10 lambs were fed diets supplemented with 5 or 10 mg Cu kg−1 DM as salts of sulfate or chloride. The two Cu salts produced equal increases in the concentration of Cu in the livers of both sheep and cattle. Key words: Sheep, cattle, liver, copper sulfate, copper chloride
INFLUENCE OF AUTOCLAVING ON THE EFFECTS OF Lathyrus sativus FED TO CHICKS
Authors: ROTTER R. G. , MARQUARDT R. R. , LOW R. K-C. , BRIGGS C. J.
Published: March 2010

The performance of chicks fed 82% (wt/wt) Lathyrus sativus (lathyrus) was significantly improved (P < 0.05) after autoclaving the seeds for as little as 5 min, but the improvement was greater with longer treatment times. Analysis of autoclaved seeds also showed a steady reduction in the concentration of the neurotoxin β-N-oxalyl-amino-L-alanine (BOAA) in lathyrus as autoclaving time increased. This may account for much of the improvement seen in chick performance. Key words: Lathyrus, autoclave, chicks, BOAA
AN ETHOGRAM OF WHITE LEGHORN-TYPE HENS IN BATTERY CAGES
Authors: WEBSTER A. B. , HURNIK J. F.
Published: March 2010

The purpose of this study was to record the ethogram of White Leghorn-type hens in cages and to note changes in behavior over the course of the laying period. Three hundred and eighty-four hens derived from two male parental stocks were randomly assigned as pairs to the cages of two three-tiered, semi-stairstep batteries. Hens within pairs were of the same stock, and the batteries were in the same room. The laying phase comprised 13 28-d periods and on the first 4 d of periods 1, 3, 5, 7, 9 and 11 video recordings were made of eight cages per day. Each cage was observed on 1 d only. The levels of occurrence of a variety of behavioral states were estimated from 60 records of the behavior of each hen obtained over an 8-h interval. Head flicking was the most prevalent of its group of mutually exclusive behavioral states, followed by eating and preening. Cage pecking appeared stereotyped in many hens, but, at a frequency of 5% of observations, was not unusually prevalent. Bobbing was primarily a prelaying behavior indicative of the restlessness prior to oviposition typical of White Leghorn hens in cages. Hens were on their feet for more than 75% of the time of observation. Physical displacement of a hen by its cagemate was commonplace. Eating was negatively correlated with head flicking and preening. Walking and bobbing were positively correlated with physical displacement. Hens became less active with time in cages, possibly due to an age effect or to behavioral adaptation to the cage environment. A second trend in behavior over time may be related to changes in levels of egg production or feed consumption. Key words: Ethogram, behavior, laying hen, battery cage
EFFECT OF A SUSTAINED-RELEASE FORM OF SOMATOTROPIN ON THE PROFILE OF MILK PROTEINS AND FATTY ACIDS DURING A FULL LACTATION
Authors: LÉONARD M. , HUNG H. T. , ROBITAILLE G. , BLOCK E.
Published: March 2010

Twenty-three Holstein cows received one injection of recombinant bovine somatotropin (bST) every 28 d at one of four doses: 0, 320, 640, or 960 mg 28 d−1. All injections started in early lactation and continued until the cows were dried-off. Composites of AM and PM milkings were analyzed for fatty acids by gas-liquid chromatography, for percent milk protein by infrared analysis and for casein by electrophoresis. For the 0, 320, 640, 960 mg cow−1 28 d−1 bST treatment groups, average ± SE milk protein percents for the entire lactation were 3.24 ± 0.08%, 3.25 ± 0.07%, 3.31 ± 0.08% and 3.24 ± 0.07%, respectively (P > 0.05); average milk caseins were 2.59 ± 0.07%, 2.61 ± 0.06%, 2.60 ± 0.07% and 2.57 ± 0.06%, respectively (P > 0.05), and average whey proteins were 0.65 ± 0.03%, 0.64 ± 0.03%, 0.71 ± 0.03% and 0.67 ± 0.03%, respectively (P > 0.05). No effect of bST was observed on milk fatty acids and protein at any dose or stage of lactation. Concentrations of αs-, β- and K-casein were not affected by bST treatment (P > 0.05). Fat percentages were 3.78 ± 0.21%, 3.91 ± 0.19%, 3.76 ± 0.19% and 4.02 ± 0.16% for the 0, 320, 640 and 960 mg 28 d−1 treatment (P > 0.05). Milk fatty acids were not affected by bST treatment (P > 0.05). Short chain fatty acids and medium chain fatty acids were decreased (P < 0.05) with progressing lactation while long chain fatty acids were increased in late lactation (P < 0.05). Key words: Somatotropin, composition of milk, caseins, milk fatty acids
SHORT-TERM THERMAL AND METABOLIC RESPONSES OF SHEEP TO RUMINAL COOLING: EFFECTS OF LEVEL OF COOLING AND PHYSIOLOGICAL STATE
Authors: NICOL A. M. , YOUNG B. A.
Published: March 2010

In a series of studies to simulate the ingestion of cold food, the rumen of adult sheep was cooled by 0–400 kJ over 1 h. Ruminal cooling reduced body heat content, increased rate of metabolic heat production and reduced apparent rate of heat loss to the environment. On average, each 100 kJ of cooling reduced heat content by 46 kJ, increased heat production by 20 kJ and reduced heat loss by 70 kJ. Precooling thermal status of the sheep affected the magnitude of the responses to cooling. A 0.1 °C higher precooling mean body temperature decreased the response in metabolic heat production by 6 kJ and increased the reduction in body heat content by 4.6 kJ. The heat production associated with eating reduced the heat loss response to ruminal cooling but did not affect the change in heat content. Well-insulated sheep were less affected by ruminal cooling. Key words: Sheep, rumen, cooling, heat production, temperature
ENERGY SUPPLEMENTATION OF HIGH FORAGE DIETS FOR MID-LACTATION DAIRY COWS
Authors: ROBINSON P. H. , BURGESS P. L.
Published: March 2010

Alfalfa silage-based rations containing corn grain, oats or tallow as the primary supplemental energy source were fed to a total of 48 mid-lactation cows in two 56-d experiments. Corn, oats or tallow were mixed with the alfalfa silage and fed ad libitum. A corn-barley-soybean meal-based concentrate was fed twice daily proportional to milk production. Overall rations varied from 55 to 70% alfalfa silage on a dry matter basis. Feed intake was lower for tallow-supplemented cows, whereas milk yield and milk proportions of fat and lactose were similar for cows in all groups. Tallow-supplemented cows produced milk with a lower protein proportion and protein yield was also lower. Tallow-supplemented cows produced milk with major shifts in milk fatty acids from most short-chain fatty acids (<C16:1) to primarily C18:1 as well as C18:0 and C20:0. Parameters of rumen fermentation were similar among all groups and did not suggest a ruminal mechanism for reduced feed intake in spite of the high level of added fat (8.6 and 6.2% of dietary dry matter in exp. 1 and exp. 2, respectively). Isoenergetic substitution of oats for corn had no negative effects on animal performance in these high-forage diets. However, addition of tallow to alfalfa silage at these levels depressed overall animal performance. Key words: Tallow, oats, corn, milk fatty acids, dairy cows