bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of ammoniation of brome-alfalfa and alfalfa hay, stored as large round bales on preservation and feed quality
Authors: Mir Z. , Robertson J. A. , Mir P. S. , Jan E. Z. , McCartney D. H.
Published: March 2010

Feeding trials with growing steers and digestibility trials with sheep were conducted during each of 3 yr in a split-split plot design, to compare the effects of anhydrous ammonia (2% wt wt−1, in plastic-covered stacks of large round bales) on preservation of brome-alfalfa and alfalfa hay harvested at < 20 and at 30% moisture with respective field cured (< 20% moisture) nonammoniated hays. Even after 14 wk of storage, the ammoniated high-moisture hays were free of visible molds. Dry matter (DM) recovery varied from 93.9 to 98.7% but was not affected by either moisture content or ammoniation. Ammoniation increased (P < 0.05) acid detergent insoluble nitrogen (ADIN, % total N) in high-moisture brome-alfalfa hay to 16.8 from 9.7% in nonammoniated hay. Within each type of hay, dry matter intake and average daily gain of growing steers were not affected by treatment. Feed efficiency was reduced (P < 0.05) in animals fed ammoniated high-moisture brome-alfalfa (11.2) but was improved (P < 0.05) in those fed ammoniated high-moisture alfalfa (9.8) when compared with the respective field cured hay (10.1 and 11.4). Compared to nonammoniated hay, ammoniating high-moisture brome-alfalfa hay had no effect on digestibilities of DM and acid detergent fiber (ADF) but decreased and increased (P < 0.05) digestibility of nitrogen (N) and neutral detergent fiber (NDF), respectively. With alfalfa, ammoniation did not affect digestibilities of either low- or high-moisture hay. Rumen volatile fatty acid profiles were not influenced but rumen fluid pH was elevated in sheep fed ammoniated hays. Results indicate that anhydrous ammonia treatment effectively preserved high-moisture alfalfa without adversely affecting nutritional quality parameters. Key words: Ammonia, brome-alfalfa, alfalfa, cattle, sheep, digestibility
The effects of copper status on thiamine metabolism in sheep fed a high sulfur diet
Authors: Olkowski A. A. , Christensen D. A. , Gooneratne S. R.
Published: March 2010

The effect of Cu status on selected aspects of thiamine metabolism was studied in sheep exposed to high dietary S over a period of 14 wk. Nine cross-bred 2-mo-old female lambs were used. The animals were divided into three groups (n = 3) and offered a basal diet containing 0.63% S (0.45% as sulfate) and 14 mg thiamine kg−1 DM. Copper and Mo were variable ingredients. Sheep in group 1 received a 14 mg Cu kg−1 DM diet, whereas those in groups 2 and 3 received a 6 mg Cu kg−1 DM diet. To precipitate Cu insufficiency, group 3 received an additional 20 mg Mo kg−1 DM diet. The concentration of blood thiamine tended to increase in sheep from group 1, but decline in sheep from group 3 which also had a lower concentration of Cu in plasma. In these groups, a similar trend was observed in thiamine and Cu concentrations of duodenal fluid. Liver thiamine tended to be higher (P = 0.09) in group 3 sheep than in group 1 and 2 sheep. However, the concentration of thiamine in the kidney and cerebral cortex did not differ among the groups. Copper concentration was lowest in the liver and brain, but highest in the kidney of sheep from group 3. The erythrocyte thiamine pyrophosphate (TPP) effect increased (P < 0.035) in sheep in groups 2 and 3 during the 8th week on the diet and in all sheep during the 13th week. We conclude that Cu plays an important role in the metabolism of thiamine in the gastrointestinal tract, as well as systemically. Key words: Sulfur, molybdenum, copper, thiamine, interactions, sheep
Association of sulfate-water and blood thiamine concentration in beef cattle: Field studies
Authors: Olkowski Andrzej A. , Christensen David A. , Rousseaux Colin G.
Published: March 2010

A population study was undertaken to survey the distribution of sulfate levels in water and thiamine status of beef cattle on Saskatchewan farms. Fifty farms took part in this study. The sampled animals represented all major breeds raised in Saskatchewan. The sulfate content in drinking water varied greatly across the province ranging from 70 to 3200 ppm. Approximately 43% of the farms from southern and central parts of the province had water with sulfate concentration exceeding 1000 ppm. The concentration of blood thiamine was (mean ± SD) 24.9 ± 10.1 μg L−1. Subsequently, a comparative study was undertaken to examine the relationship between high sulfate in the drinking water and blood thiamine concentration in feedlot cattle. The farms with high (> 1000 ppm) and low (< 200) levels of sulfate in the water were used for the comparative study. Blood thiamine concentrations differed (P < 0.0001) between beef cattle drinking low sulfate-water and those drinking high sulfate-water and were 47.3 ± 9.8 and 37.9 ± 12.4 μg L−1 respectively. It was concluded from this study that a high concentration of sulfate in the drinking water has a detrimental effect on blood thiamine status. A subpopulation of beef cattle in Saskatchewan may be marginally deficient or deficient in thiamine. Key words: Water, sulfate, cattle, blood, thiamine, deficiency
Effects of triticale (cv. Beaguelita) and barley-based concentrates on feed intake and milk yield by dairy cows
Authors: McQueen R. E. , Fillmore A. E.
Published: March 2010

Triticale (cv. Beaguelita) was compared with barley in concentrate mixes for lactating Holstein cows. Grains in the concentrate mixes were 100% barley (B), 57% barley and 43% triticale (BT) or 14% barley and 86% triticale (T). Alfalfa silage (15% crude protein (CP), 62.2% dry matter (DM) digestibility) was fed ad libitum and the concentrates were fed twice daily at 1 kg per 2.75 kg milk produced. Twenty-one lactating cows were allocated to the three diets for an 11-wk trial with three repeated measures of responses (periods). There were no linear or quadratic effects due to dietary treatments (P > 0.05) on mean dry matter consumption of concentrate and alfalfa silage by cows fed the three diets, with average daily intake of concentrate and forage (kg d−1), respectively being: B, 8.2 and 13.3; BT, 8.8 and 12.2; T, 8.3 and 12.2. Replacing barley with triticale also was not related to 4% fat-corrected milk yield (kg d−1) (P > 0.05) which was 23.6, 26.6 and 24.7 for diets B, BT and T, respectively. Similarly the fat, protein and lactose contents of the milk were not related to the proportions of barley and triticale in the diets. There was a linear reduction in body weight gain as triticale levels increased in the diets (P < 0.05). Rumen fluid pH and ammonia concentration were not affected by triticale levels in the diets. However, the molar concentrations of acetate, propionate, butyrate and valerate tended to increase linearly (P < 0.10) with triticale levels. The rates of disappearance of DM and CP of barley were faster than for triticale from nylon bags incubated in situ in the rumen but the solubilities of DM and CP at zero time of triticale were greater (P < 0.01). Concentrate mixes BT and T containing triticale were readily accepted by dairy cows and supported milk yields similar to one based on barley. However, body weight gain was reduced in cows fed triticale indicating that more of the productive energy was expressed in milk production. Key words: Triticale, barley, lactation
Biological value of crude protein for sheep fed timothy hay
Authors: Hironaka R. , Bailey C. B. , Rode L. M. , Schaalje G. B.
Published: March 2010

Protein balance trials with four sheep were conducted with mixtures of a single variety of grass hay containing 4.36–14.46% CP (N × 6.25). The data were used to calculate the minimum urinary CP excretion and the biological value of the ingested CP. Minimum daily urinary CP excretion was 1.08 g BW−0.75. Biological value was calculated to be 0.70 at a dietary CP content of 6.79%. Key words: Biological value, protein, sheep, timothy, hay
Relationship of weather and plant factors to alfalfa bloat in autumn
Authors: Hall J. W. , Majak W.
Published: March 2010

The bloat status of cattle was recorded in the autumns of 6 yr when bloat occurred during the decade 1979–1988. Weather data were available for all 6 yr, plant dry matter, acid detergent fiber and plant chlorophyll for 3 yr and plant total nitrogen and soluble nitrogen for 4 yr. The percentages of dry matter and acid detergent fiber were lower and the concentrations of chlorophyll, total nitrogen and soluble nitrogen were higher on days when bloat occurred than when it did not. There was no difference in minimum temperature classified by bloat status on the same day, or in maximum temperature, hours of sunshine or precipitation classified by bloat status on the next day. Hours of sunshine and the temperature range were greater on days when bloat occurred. Bloat was observed after "killing frosts" of −2.2 °C in all years and in an extreme case after a daily minimum of −9.6 °C. Key words: Legume, bloat, alfalfa, cattle, climate
Composition and digestibility of canola press cake as a feedstuff for use in swine diets
Authors: Keith M. O. , Bell J. M.
Published: March 2010

Samples of canola press cake (PC) were collected from seven crushing plants in Western Canada over four successive weekly sampling periods to assess its nutrient and glucosinolate composition and variability. The digestibility of energy and crude protein (CP) (N × 6.25) of PC in growing pigs was also determined. Compared to canola meal (CM), PC contained more ether extract (EE) (21.21 vs. 3.92%), more gross energy (GE) (23.92 vs. 20.36 MJ kg−1) and less CP (34.10 vs. 41.85%), dry matter (DM) basis (P < 0.05). There were significant differences (P < 0.05) among crushing plants in the contents of EE, GE and CP in PC with the largest differences observed in EE; sampling period effects were small for all three components. Plant and period effects on amino acid concentrations in PC were similar to those effects on CP. Glucosinolate concentrations (oil-extracted DM basis) showed only slight reductions in PC from those in canola seed (CS). Both CS and PC concentrations were greater than in CM (P < 0.05) but myrosinase activity in PC was reduced to 0.65% of that in CS compared to 0.15% remaining in CM. Differences were found in total aliphatic glucosinolate concentrations among crushing plants (P < 0.05) (mean 23.75 μmol g−1) with only minor period effects. The digestibility of GE in PC was 75 % and of CP 75%. On DM basis PC contained 17.94 M J of digestible energy kg−1 and 25.6% digestible CP. Key words: Canola, press cake, composition, variability, digestibility, pigs
The effects of a linear increase in dietary indole glucosinolates on growth and physiology of mice
Authors: Darroch C. S. , Bell J. M. , McGregor D. I. , Mills J. H. L.
Published: March 2010

An extract of indole glucosinolates (GSLs) isolated from Brussels sprouts (Brassica oleracea) was incorporated into semipurified diets to study the effects of indole GSLs on growth, feed mtake and thyroid, liver and kidney function over a 16-d period. Increasing levels (0.2–8.2 μmol g−1 DM) of dietary indole GSLs, primarily indolyl-3-methyl-GSL, decreased feed intakes of mice linearly (P < 0.01) throughout the trial; growth rates were also reduced (P < 0.05). Palability problems were encountered when mice were first exposed to diets containing intermediate levels (4.2–6.2 μmol g−1 DM) of indole GSLs but mice adapted to their presence and this was reflected by compensatory growth. Feed intakes of mice fed diets containing 8.2 μmol indole GSLs g−1 DM were lowered dramatically which resulted in an increase in mortality. Mortality may have resulted from a toxic effect of indolyl-3-methyl-GSL or indoleacetonitrile but was most likely a result of starvation. Indole GSLs from the extract were not goitrogenic and had no apparent effect on thyroid, hepatic or renal weights or morphology. It was concluded that dietary indole GSLs, primarily indolyl-3-methyl-GSL, below 3 μmole g−1 DM did not adversely affect growth performance in mice and may have contributed to a small improvement in feed efficiency. Key words: Indole glucosinolates, growth, feeding value, mice
Effects of shearing and prebreeding ram exposure on days to first mark and pregnancy rate of ewe lambs
Authors: Kemp R. A. , Lane S. F. , Berger Y. M.
Published: March 2010

Crossbred ewe lambs were used to examine effects of shearing and prebreeding ram exposure on age at puberty and pregnancy rate. Shearing did not significantly affect age at puberty or growth rate of ewe lambs. Prebreeding ram exposure and/or shearing did not influence pregnancy rate. Key words: Shearing, ram exposure, pregnancy rate, growth
Effect of defaunation and refaunation of the rumen on cellulolytic activity in vitro with or without ammonia supplementation
Authors: Ushida K. , Kojima Y.
Published: March 2010

The effect of defaunation and refaunation of the rumen on cellulose digestion in vitro was examined with special reference to ammonia supply. Digestion of cellulose by DF and RF rumen populations was measured using a simple in vitro batch system with or without ammonia supplementation. Ammonia was supplied to the cultures either as ammonium sulfate or ammonium chloride solution. Cellulose digestion was increased by the presence of either protozoa or ammonia. The protozoal effect was evident in the absence of ammonia supplementation and the ammonia effect was evident in the absence of protozoa. The form of the ammonia supplement did not affect cellulose digestibility. Key words: Protozoa, ammonia, cellulose digestion
Comparisons of responses in whole blood and plasma selenium levels during selenium depletion and repletion of growing cattle
Authors: Nicholson J. W. G. , Allen J. G. , Bush R. S.
Published: March 2010

Cattle with high or moderate Se status were used in two Se repletion-depletion studies to compare response in Se content of whole blood or plasma. Changes in whole blood values gave a better indication of current Se intake because the magnitude of change was greater than in plasma and values did not plateau at as low a level of intake. Key words: Selenium, cattle, whole blood, plasma
The utilization of acid-preserved poultry offal by growing-finishing pigs
Authors: Lunen T. A. Van , Anderson D. M. , St. Laurent A.-M. , Barclay J. , Nicholson J. W. G.
Published: March 2010

Poultry offal hydrolysate (POH) was fed to pigs from 20 to 100 kg at levels of 0, 5, 10 or 15% DM in two feeding trials. Increasing levels of POH resulted in linear depression in growth rate (0.80–0.68 kg d−1) and daily feed consumption (2.4–2.0 kg d−1). Carcass characteristics were unaffected by POH inclusion. Key words: Poultry offal, pigs, utilization
The effects of fiber supplementation on diet digestibility by silver foxes
Authors: Faulkner W. L. , Anderson D. M.
Published: March 2010

A digestibility study with Silver foxes weighing 6.5 ± 0.1 kg was conducted to evaluate five fibers (hemicellulose (X), α-cellulose (C), pectin (P), oat bran (B) and oat hulls (H)) added at 5% to a meat-type diet (A). Apparent digestibility of dry matter in diet P (65.1%) was significantly poorer (P < 0.05) than all others except C (69.1%). Addition of all fibers reduced digestibility of acid detergent fiber. Diet P resulted in weight loss, increased water consumption, and faster rate of passage than diet A (P < 0.05). Key words: Digestibility, oat bran, rate of passage, hemicellulose, fiber, fox
Dietary energy and protein intake, plasma progesterone and embryo survival in early pregnancy in the gilt
Authors: Pharazyn A. , Foxcroft G. R. , Aherne F. X. , Hartog L. A. Den
Published: March 2010

Two levels of energy and protein fed to gilts from days 3 to 15 of gestation had no effect on plasma progesterone in early pregnancy or embryo survival to day 28. However, overall, day 3 progesterone concentrations were positively related to embryo survival (P < 0.09) and inversely related to variance in survival (P < 0.07). Key words: Gilt, progesterone, embryonic loss, pregnancy
Effect of protein precipitating agents on the recovery of plasma free amino acids
Authors: Sedgwick G. W. , Fenton T. W. , Thompson J. R.
Published: March 2010

The effect of the protein precipitants acetone, acetonitrile, perchloric acid and trichloroacetic acid on free amino acid concentrations in supernatants from ovine plasma and bovine serum albumin solutions was determined. The organic precipitants decreased (P < 0.05) free amino acid concentrations in a protein concentration dependent manner while the acid precipitants had no effect. Key words: Amino acids, protein precipitating agents
The prediction of pork carcass composition using the Hennessy Grading Probe and the Aloka SSD-210DXII Echo Camera
Authors: Sather A. P. , Newman J. A. , Jones S. D. M. , Tong A. K. W. , Zawadski S. M. , Colpitts G.
Published: March 2010

Carcasses, with an average weight of 80.8 kg, from 130 Lacombe and 96 Yorkshire pigs were probed for fat and muscle depth at the carcass grade site using the Hennessy Grading Probe (HGP). Similar data were collected by the Aloka SSD-210DXII Echo Camera (AEC) at the carcass grade site and at the Canadian Swine Improvement Program loin and mid-back sites. Muscle-width and muscle-area measurements were also made with the AEC. The R2 (residual standard deviation: RSD), using the HGP, for prediction of carcass lean yield at the grade site using fat and muscle depth was 0.58 (16.4). When fat and muscle depth were measured by the AEC, the R2 (RSD) at the mid-back, loin and grade sites to predict carcass lean yield was 0.41 (19.7), 0.47 (18.5), and 0.53 (17.5), respectively. When the AEC muscle-depth measurements were replaced with muscle-area measurements, the R2 increased (RSD decreased) at the mid-back, loin and grade sites to predict carcass lean yield (0.60 (16.0), 0.64 (15.2), and 0.59 (16.4), respectively). Real-time ultrasound (AEC) provides precision for the prediction of carcass lean content similar to that of the electronic grade probe (HGP). However, combining fat- and muscle-depth measurements made by the HGP with muscle-area measurements made by the AEC at the loin increased the R2 from 58 to 66% for the prediction of carcass lean yield. The suitability of the use of real-time ultrasound as an alternative to electronic grading probes, at this time, appears to be limited. Key words: Swine, real-time ultrasound, carcass grading
The prediction of pork carcass composition using live animal echographic measurements from the Krautkramer USK7, Ithaca Scanoprobe 731C and Aloka SSD-210DXII Echo Camera
Authors: Sather A. P. , Newman J. A. , Jones S. D. M. , Tong A. K. W. , Zawadski S. M. , Colpitts G.
Published: March 2010

Live animal ultrasonic measurements of back fat depth and muscle depth were made on 130 Lacombe and 96 Yorkshire pigs within a weight range of 85.5–114.2 kg, using a Krautkramer USK7 (KK), an Ithaca Scanoprobe 731C (SC) and an Aloka SSD-210DXII Echo Camera (AEC), with an average carcass weight of 80.8 kg. Animals were assessed 1 d prior to slaughter at the mid-back and the loin site as specified by the Canadian Swine Improvement Program and the carcass grade site. Back fat depth measurements made by the SC, KK and AEC reduced the residual variance for lean yield by an additional 35, 43 and 45%, respectively, beyond adjusting for gender, breed and live weight. The mid-back site had less precision than the loin or grade sites for the prediction of both lean yield and fat yield, and there were no clear advantages for using the loin site in preference to the grade site. Since there are no easily identifiable landmarks for locating the grade site on the live pig, the loin site remains the preferred site for live animal evaluation. The addition of muscle-depth measurements to fat-depth measurements resulted in modest increases in the R2 (1–4%) in precision for the prediction of carcass composition. Differences in the ability of the KK and AEC to predict lean yield were small and, considering their cost, suggest that the application of real-time ultrasonics to live animal evaluation may not be practical at this time. Key words: Swine, ultrasound, lean yield, probe sites
Growth performance and carcass composition in beef heifers undergoing catch-up (compensatory) growth
Authors: Yambayamba E. , Price M. A.
Published: March 2010

Fifty-three Hereford crossbred heifers (211 ± 28 (mean ± SD) kg; 197 ± 13 d of age at day 1) were used to study catch-up growth and its effects on carcass composition. Five heifers were slaughtered on day 1; the remaining 48 were randomly penned in groups of six and assigned to treatments as follows: three pens to ad libitum feeding (target gain > 1.0 kg d−1); three pens to 2 mo of feed restriction (target gain 0.5 kg d−1); followed by realimentation; and two pens to 4 mo of feed restriction (target gain: 2 mo at 0.5 kg d−1 and 2 mo at 0.0 kg d−1) followed by realimentation. Animals from one pen were slaughtered from each treatment after 2 mo, after 4 mo, and at a final slaughter weight of about 410 kg. During the final period (4 mo to slaughter), growth rate was greater (P < 0.05) in the 4-mo than in the 2-mo restricted–realimented animals or the ad-libitum-fed animals (1.91 vs. 1.18 vs. 1.02 kg d−1), respectively. Feed restriction for 2 mo had no significant effect on the composition of the three-rib cut, but 4 mo of feed restriction was associated with significantly lower and higher (P < 0.05) proportions of fat and bone, respectively, in the three-rib cut. Muscle proportion was not affected by treatment. At the final slaughter weight, no significant differences were found among treatments in the tissue proportions of the three-rib cut. It is concluded that 2 or 4 mo of feed restriction, starting at 6 mo of age, has no permanent effect on a heifer's live weight or body composition. Key words: Heifers, feed restriction, realimentation, compensatory growth, carcass composition
Fiber-type proportions and diameters in the longissimus muscle of beef heifers undergoing catch-up (compensatory) growth
Authors: Yambayamba E. , Price M. A.
Published: March 2010

Fifty-three Hereford crossbred heifers (211 ± 28(mean ± SD) kg, 197 ± 13 d of age at day 1) were used to study the effects of mild, chronic feed restriction followed by refeeding on some longissimus muscle fiber characteristics. Five animals were slaughtered on day 1 for analysis of initial muscle fiber characteristics. The remaining 48 animals were randomly penned in groups of 6 and assigned to treatments as follows: three pens to ad libitum feeding; three pens to 2 mo of feed restriction followed by refeeding, and two pens to 4 mo of feed restriction followed by refeeding. Animals in one ad libitum and one restricted pen were slaughtered after 2 mo and those in one pen from each treatment after 4 mo, and the remainder at the final slaughter weight of about 410 kg. Two months of feed restriction had no effect on the proportions of longissimus muscle fiber-types, "red" (βR), "white" (αW), and "intermediate" (αR), but fiber diameters were smaller (P < 0.05) in the restricted than in the ad-libitum-fed animals. Four months of feed restriction was associated with a relatively higher (P < 0.05) proportion of βR fibers and lower (P < 0.05) proportion of αW fibers than ad libitum feeding. Muscle fiber diameters were larger (P < 0.05) in the ad-libitum-fed than in the restricted heifers. No significant feeding treatment differences were found in fiber-type proportions or fiber diameters at the final slaughter weight. Key words: Heifers, feed restriction, realimentation, muscle fibers, fiber-type, compensatory growth
Response of growth hormone to various doses of growth hormone releasing factor and thyrotropin releasing hormone administered separately and in combination to dairy calves
Authors: Løvendahl Peter , Woolliams John A. , Sinnett-Smith Patrick A.
Published: March 2010

Doses of growth hormone releasing factor (GRF) and thyrotropin releasing hormone (TRH) and combinations of these were administered by intravenous injection to six calves aged 155 ± 3 days and weighing 136 ± 16 kg. Injections were at 09:00, 12:00 and 15:00 h on 4 days, and doses were 0, 15, 30 and 60 pmol GRF kg−1 and 0, 275, 550 and 1100 pmol TRH kg−1, with GRF plus TRH at all combinations of these doses. Response of serum growth hormone (GH) was measured as the mean at 5, 10, 15 and 20 min following injection (PEAK) and the area under the curve during 0–60 min (AUC). The correlation between PEAK and AUC was 0.98. The variation in PEAK was related to GH prior to injection and to PEAK 3 h earlier. Separate multiplicative effects for each secretagogue were fitted, with the effects related to the logarithm of dose. Doubling the dose increased PEAK by 1.46-fold following GRF (P < 0.05) and 1.25-fold following TRH (P < 0.05). There was no evidence that the results for either secretagogue were affected by the presence or absence of the other. This multiplicative model provides a description of the synergy between these secretagogues. Key words: GH-release, GRF, TRH, calves, dose response
Effect of somatotropin and protein supplement on thyroid function of dairy cattle
Authors: McClean C. , Laarveld B.
Published: March 2010

Somatotropin (ST) treatment may impair the hypothalamic–pituitary–thyroid axis in dairy cattle and may therefore exacerbate the low goitrogenic potential of canola meal (CM). Four cows and four heifers, in a double Latin square design, were treated with pituitary bovine ST (30 mg d−1) or excipient during the last 14 d of each 28-d trial period. Treatments consisted of barley-based diets containing either CM or soybean meal (SBM) with or without ST treatment. Milk production, milk composition, feed intake and body weight were determined regularly. On the final day of each period, blood samples were taken prior to and following a thyrotropin-releasing hormone (TRH) challenge (0.5 μg kg−1 BW) to determine basal and response levels of thyrotropin (TSH), ST, thyroxine (T4), and triiodothyronine (T3) resulting from each treatment. Somatotropin increased milk and fat corrected milk (FCM) production (9 and 11%, respectively). Milk composition, feed intake, feed efficiency and body weight were unaffected by treatment. Canola meal decreased milk iodide (I−) and increased milk thiocyanate (SCN−) without any effect of ST treatment. Somatotropin treatment increased plasma ST levels without dietary effects. Significant period × treatment interactions were associated with the TSH, T4 and T3 data. The levels of all hormones were within normal physiological ranges and indicated a euthyroid state. In addition, there were no differences between treatments in the responses of ST, TSH and T4 to the thyroid challenge test. We conclude that ST treatment at this dose, duration and stage of lactation does not impair the hypothalamic–pituitary–thyroid axis of dairy cattle. Key words: Somatotropin, dairy cattle, thyroid, canola meal, goitrogens
The influence of monensin and lasalocid on the breeding performance of ewes and the endocrine status of ewe lambs
Authors: Kirkwood R. N. , Thacker P. A. , Rorchinski R. S. , Gonzalez A. , Laarveld B.
Published: March 2010

Two experiments were performed, in December and August, to determine the effects of dietary ionophores on the breeding performance of ewes and the endocrine status of ewe lambs. Experiment 1 employed 127 mixed-parity ewes fed diets containing 33 ppm monensin (M, n = 43), 45 ppm lasalocid (L, n = 43) or no additive (C, n = 41). Estrus was synchronized with progesterone sponges and the ewes were allowed to breed. The proportion of ewes conceiving at their first estrus was higher (P < 0.05) for control ewes than for L ewes (70.7 vs. 51.2%) M ewes being intermediate (53.5%). Litter size of ewes conceiving at first estrus was not affected by treatment. Experiment 2 employed 57 ewe lambs allocated in a 3 × 2 factorial arrangement to be fed rations containing 33 ppm M, 45 ppm L or no additive for 26 d and to receive, or not, an injection of 50 μg GnRH at 21 d. For lambs receiving GnRH, blood samples were taken every 15 min for 2 h from 30 min pre-injection. At 72 h after GnRH injection, all lambs received an injection of 50 μg estradiol-17β. Further blood samples were taken from all lambs at 4-h intervals for 48 h. Serum LH and FSH concentrations increased from pre-injection means of 1.6 ± 0.2 and 7.8 ± 1.2 ng mL−1 to 20.9 ± 1.9 and 13.4 ± 1.4 ng mL−1, respectively, by 15 min after GnRH injection. These responses were not affected by either ionophore. The estradiol-induced LH surge height was reduced (P < 0.01) in lambs that had received GnRH. These data indicate that at the dietary inclusion levels employed, ionophores may be contra-indicated in the breeding ration. Key words: Ionophores, ewes, reproduction
Gastrointestinal motility and plasma hormone and metabolite responses to acute cold stress and somatostatin-14 in sheep
Authors: Christensen R. A. , Kennelly J. J. , Christopherson R. J.
Published: March 2010

Effects of intrajugular infusions of somatostatin-14 (SS-14) (8.9, 18.4, and 37.3 ng min−1 kg−1 BW) or saline were studied in three acutely (2 h) cold-stressed (0 °C) ewe lambs (39.8 ± 1.8 kg BW) fed a barley soybean meal diet at 25.6 g DM d−1 kg−1 BW. Acute cold exposure transiently increased (P < 0.001) and rewarming decreased (P < 0.001) recticular contraction frequency, with no effect of SS-14. The duration of duodenal irregular spiking activity was decreased (P < 0.05) by SS-14 at doses of 18.3 and 37.3 ng min−1 kg−1 and was not affected by cold exposure. This resulted in a decrease (P < 0.05) in the average duration of the individual migrating myoelectric complex. Cold exposure increased (P < 0.01) plasma concentration of free fatty acids (FFA). Orthogonal contrasts of the changes during somatostatin infusion indicated linear increases in glucose and linear and cubic increases in FFA concentrations in plasma (P < 0.05). Infusion of somatostatin had no effect on basal concentrations of growth hormone, insulin, or glucagon but produced linear reductions in plasma insulin and glucagon responses during cold exposure (P < 0.05). Somatostatin modestly influenced hormone and metabolite concentration during acute cold exposure without apparent effect on body temperature. Key words: Cold, somatostatin, sheep, gastrointestinal motility, glucagon, insulin
Maintaining a high physiological rate of testosterone secretion in the adult ram by estradiol immunoneutralization partially prevents testicular regression
Authors: Sanford Lee M. , Leggee Donna G. , Melnyk Peter M.
Published: March 2010

The seasonal testicular cycle of 10 adult Dorset × Leicester × Suffolk rams was entrained to alternating 4-mo periods of long-inhibitory (16 h light) and short-stimulatory (8 h light) day lengths. Beginning in the third month of a short-day period, when the testes were fully redeveloped, five rams were passively immunized with a low titre (1:200) of estradiol antiserum for 13 wk. During this time the testes of the remaining (control) rams regressed almost completely. Estradiol immunoneutralization reliably maintained most characteristics of testosterone secretion (mean and base-line concentrations, and pulse amplitude) at "breeding season" values and had a minor but persistent effect on the hypothalamic–pituitary axis. When both the immunization period and the following 6 mo were considered, LH pulses were 50% larger in the immunized rams than in the control rams. Testicular regression was partially prevented in the immunized rams. However, their 1.5- to 1.7-cm larger scrotal circumference during most of the regression stage was not associated with a greater daily sperm output (based on sperm voided in urine) early in the redevelopment stage. Mean LH and FSH concentrations were increased by 200% in all rams during testicular recrudescence, and maximum testis size was achieved 1 mo earlier in the immunized rams than in the control rams. Immunization of rams against estradiol effectively maintained a high physiological rate of testosterone secretion, but was not able to prevent the normal decline in quantitative spermatogenesis. Key words: Estradiol immunoneutralization, testicular regression, testosterone, adult ram
In vitro digestibility of forages supplemented with cellulose (filter paper) and branched-chain fatty acids or amino acids
Authors: Mir P. S. , Mir Z. , Pink B. M.
Published: March 2010

In vitro studies were conducted to determine dry matter (DM) digestibility of filter paper (FP), alfalfa hay (AA), corn silage (CS) and barley silage (BS) containing (as percent of DM) 0, 20 and 40% of FP and 0, 2 and 4% of either isoleucine (ILE) for CS, BS and FP, or its metabolite 2-methyl butyric acid (2MB) for AA. Digestibility of acid detergent fibre (ADF) of AA, CS and FP and of combinations of these forages with FP was determined. Digestibility of DM was determined after incubation with rumen fluid only or employing the two-stage Tilley and Terry technique. ADF digestibility was calculated after determining ADF in the original material and the residue after incubation for DM digestibility. Inclusion of FP increased (P < 0.05) digestibility of DM and ADF from 57.3 and 42.0 to 73.9 and 76.9% for AA and from 71.7 and 64.8 to 79.3 and 81.7% for CS, respectively. DM digestibility of BS increased (P < 0.05) from 65.7 to 74.6%. Addition of ILE to FP resulted in a quadratic (P < 0.05) increase in DM and ADF digestibility from 43.7 to 55.4 to 52.0% and from 47.4 to 55.1 and to 60.4%, respectively. Microbial protein produced after incubation with rumen fluid of all the forages and forage-FP combinations was determined using cytosine as a marker. Cytosine was determined in the incubated material and in the centrifugate. Increases in microbial protein production after addition of cellulose were noted for AA only. Key words: In vitro digestibility, forages, filter paper, isoleucine, 2-methyl butyric acid, cytosine, microbial protein
Effect of forage type and supplemental dietary vitamin E on milk oxidative stability
Authors: Nicholson J. W. G. , St-Laurent Anne-Marie
Published: March 2010

Twelve Holstein cows in each of two replicates were used to determine the effect of forage type and vitamin E supplementation on the oxidative stability of milk. Alfalfa or corn silage was fed ad libitum as the sole roughage, with a concentrate to milk ratio of 1:2.5. Half the cows on each forage were fed 7000 IU d−1 of dL-α-tocopherol acetate top-dressed on the concentrate in two feedings per day over a 4-wk period. Cows consuming the alfalfa silage had higher (P < 0.05) plasma vitamin E content, but there were no differences in milk vitamin E or flavor due to forage type. Supplementing the diets with vitamin E resulted in higher (P < 0.01) vitamin E content of plasma and milk and improved milk oxidative stability. There was an interaction (P = 0.03) between forage type and vitamin E supplementation for oxidative flavor score in week 2. Supplementing the corn silage diet with 7000 IU d−1 of vitamin E resulted in almost complete elimination of oxidized flavor in milk within 1 wk of starting supplementation. However, supplementing the alfalfa silage diet had no effect on flavor over the first 3 wk of feeding. It is apparent that the vitamin E content of milk is not the sole determinant of its oxidative stability. Key words: Spontaneous oxidation, flavor, milk, vitamin E, alfalfa, corn silage, cow
Herring silage as a protein supplement for young cattle
Authors: Nicholson J. W. G. , Johnson D. A.
Published: March 2010

Fish silage made by grinding herring and adding formic acid, β-hydroxytoluene and potassium sorbate was evaluated as a protein supplement for young cattle. Only about 15% of the crude protein in the herring silage was true protein. Ammonia N accounted for 8% of the crude protein and most of the rest was peptides and free amino acids. The crude protein of herring silage was as resistant as fish meal to deamination when fermented in rumen fluid, and more resistant than soybean or casein. The herring silage was readily accepted by Holstein heifers fed hay or grass–legume silage with potatoes (7 kg d−1) and a supplement (1.5 kg d−1). Feed intake and weight gain were similar when the heifers were fed hay with either soybean meal or herring silage but were higher when forage silage replaced the hay. Rumen fluid NH3-N and blood urea levels were normal, even for cattle fed the high non-protein N diet of forage silage with herring silage. The herring silage depressed rumen fluid acetate levels and increased propionate in the heifers fed hay + potatoes, probably because of the unsaturated fatty acids in the herring. Well-made herring silage was a suitable protein supplement for young cattle fed forage and potato diets. Key words: Herring silage, fish silage, potatoes, cattle, protein degradation
The influence of zeranol implantation on growth and reproduction of beef heifers
Authors: Kirkwood R. N. , Cohen R. D. H. , King B. D. , Thacker P. A.
Published: March 2010

Crossbred beef heifers received a 36-mg implant of zeranol at 60 d of age (R1; n = 35) or at both 60 and 197 d (weaning; R2; n = 32) or received no implants (C; n = 35). R2 heifers were heavier and had greater pelvic areas (P < 0.05 for both) at breeding compared with controls. There was no effect of treatment on the calving rates (78.1 vs. 80.0 vs. 74.3%) or on mean pelvic area at the time of calving (261.1 vs. 260.4 vs. 257.6 cm2) for R2, R1 and C heifers, respectively. We conclude that zeranol can be successfully used for growth enhancement from 60 d of age without detriment to subsequent reproductive performance. Key words: Zeranol, heifers, pregnancy rate, pelvic area
Effect of insulin on the concentration of glucose and hormones in serum and milk yield of postpartum ewes
Authors: Pope T. C. , Hallford D. M.
Published: March 2010

Eighteen mature Debouillet ewes with single lambs received either 0, 0.25 or 0.50 IU Lente insulin per kilogram body weight per day on days 11 through 20 postpartum. Hourly blood samples were obtained from 1 h before to 6 h after treatment on days 11 and 20. Serum insulin concentration was increased by 1 h after insulin injection on day 11 and was accompanied by a decrease in serum glucose concentration. By 6 h after treatment on days 11 and 20, serum glucose and insulin in ewes receiving 0.25 IU insulin had returned to control levels. Exogenous insulin did not induce ovarian cyclicity. Key words: Sheep, insulin, postpartum, anestrus, prolactin, somatotropin
The effects of ruminal protozoa on selenium status in sheep
Authors: Dayrell M. de S. , Ivan M. , Hidiroglou M.
Published: March 2010

Fauna-free and faunated Canadian Arcott rams (21 and 23, respectively) were fed a corn silage diet supplemented with soybean meal for 110 d. Ruminal protozoa had no effect (P > 0.05) on plasma selenium concentrations but decreased the selenium concentration in the kidney cortex (P < 0.01), liver (P < 0.05), and spleen (P < 0.01). Key words: Sheep, selenium, Protozoa
Effects of time and level of energy supplementation on intake and digestibility of low-quality tall fescue hay by sheep
Authors: Howard M. D. , Muntifering R. B. , Howard M. M. , Hayek M. G.
Published: March 2010

Effects of time and level of energy supplementation on forage intake, nutrient digestibility and ruminal pH were investigated with sheep fed low-quality tall fescue hay either alone (control; C) or supplemented (S) with concentrate at 10 (low; L) or 20% (high; H) of ad libitum forage intake; supplement was offered at 08:00 or 15:00 h. Supplementation increased (P < 0.05) digestible dry matter intake (DMI), total tract organic matter digestibility, N intake, and N digestibility, but decreased (P < 0.05) mean and minimum ruminal pH compared with C. Offering supplement at 08:00 h increased (P < 0.05) forage and total DMI, N intake, fecal N excretion and maximum ruminal pH, but lowered (P < 0.05) total tract digestibility of acid detergent fibre (ADF) and organic matter, and mean and minimum ruminal pH compared with 15:00 h. A high level of supplementation increased (P < 0.10) digestible DMI, postruminal digestion of neutral detergent fibre (NDF), and hemicellulose (HC), but lowered (P < 0.01) ruminal digestion of HC and NDF (P < 0.10), mean ruminal pH (P < 0.10) and total tract ADF digestion (P < 0.05) compared with L. These data suggest that the substitution effects of concentrate feeding on forage intake can be mitigated by changing the time of day when supplement is offered in relation to forage. Key words: Supplementary feeding, feed intake, digestibility, sheep
Digestibility and performance of dairy bulls fed corn and grass silages with various sequences and levels of barley
Authors: Flipot P. M. , Petit H. V. , Girard V. , Bernier-Cardou M.
Published: March 2010

Sixty Canadian Holstein male calves (mean weight 261 kg), previously fed all-concentrate diets, were allocated to one of six different sequences of barley supplementation. Rolled barley was provided in the diet at three levels (0, 17 and 34% on a DM basis) with either grass or corn silages, and fed as a total mixed ration for 91, 77 and 70 d during periods 1,2, and 3, respectively, to ensure consumption of 330 kg of barley per animal for the entire experiment. Barley supplementation in the last period improved average daily gain over the whole experiment by 0.223 kg d−1 (P = 0.0154), and feed efficiency by 55% (P = 0.0062) compared to inclusion of barley in the silage mixtures during the first period. Feed efficiency improved with concentrate supplementation of both silages (P ≤ 0.0001), but the improvement with grass silage was greater than with corn silage (P = 0.0041). Dry matter and energy digestibilities were not affected by feed sequences (P = 0.1025, P = 0.0833, respectively), but they were higher for mixed diets than for pure silage (P = 0.0186, P = 0.0218, respectively). Dry matter intake was 0.81 kg d−1 higher (P ≤ 0.0001) when concentrate was added to the diet. These results suggest that energy feeds such as barley are more efficiently used in the last part of growth. This experiment demonstrates the feasibility of switching grain-fed calves to roughage diets. Key words: Barley, dairy bulls, energy distribution, corn silage, grass silage
Rumen protection of heat-treated soybean proteins
Authors: Mosimanyana B. M. , Mowat D. N.
Published: March 2010

The effects of processing variables on soybean crude protein (CP) ruminal degradation were investigated. Soybean meal (SBM) was heated in a forced-air oven (90 °C, 1 h) with blood (0, 5, 10 and 20% dry matter) and/or xylose (3 mol mol−1 SBM-blood lysine) in a randomized complete block design. In another experiment, whole soybeans were utilized using the following treatments: raw; roasted (in Gem Co. unit exit temperature 150 °C) and steeped for 0 or 2 h; roasted, flaked (exit temperature 111 °C) and steeped for 0, 1, 2, 3 h or 1 h with 4% xylose and/or 10% blood. Solubility of SBM CP was reduced (P < 0.01) by the addition of xylose, without adverse effects on pepsin-digestible CP and acid detergent insoluble nitrogen. In situ degradation of CP (EDCP), assuming a passage rate of 5% h−1, of SBM was reduced by the addition of blood (P < 0.05) and particularly xylose (P < 0.01). Soybean CP solubility was reduced (P < 0.01) by roasting and flaking (65.6 vs. 17.6% total CP). Not flaking the roasted beans further reduced (P < 0.01) CP solubility (to 10.4%) probably due to less rapid cooling. The EDCP of raw soybeans (87.6%) was reduced by roasting (64.2%), steeping whole (57.6%) or flaked (61.1%) beans. These data support xylose to effectively reduce ruminal degradation of SBM and simple steeping (1 h) with or without flaking to further reduce EDCP of roasted soybeans. Key words: Soybean meal, soybeans, xylose, blood, steeping, protein degradation
Effect of salinomycin and enzyme supplementation on nutrient digestibility and the performance of pigs fed barley- or rye-based diets
Authors: Thacker P. A. , Campbell G. L. , GrootWassink J. W. D.
Published: March 2010

Two experiments of a factorial design (sex × treatment) were conducted to determine the effects of enzyme and salinomycin supplementation on the nutritive value of barley or rye-based diets for growing pigs fed from approximately 20 to 85 kg. For exp. 1, 72 crossbred pigs were fed either a barley-based control diet or a similar diet supplemented with enzyme (Aspergillus niger; 750 units g−1 beta-glucanase and 650 units g−1 pentosanase), salinomycin (25 ppm) or both additives in combination. For exp. 2, two replicates of 48 pigs were fed either a barley-based diet, an unsupplemented rye-based diet or a rye-based diet supplemented with enzyme, salinomycin or both additives. During both experiments, chromic oxide (0.5%) was added to the diet of four to six pigs/treatment to act as a digestibility indicator starting when the pigs reached 42 kg. Neither enzyme nor salinomycin, alone or in combination, significantly improved the growth rate or feed efficiency of pigs fed barley or rye. Supplementation of barley with the combination of additives significantly (P < 0.05) improved protein digestibility while neither enzyme nor salinomycin had any effect on nutrient digestibility when fed alone. In rye-based diets, salinomycin, both alone and in combination, significantly (P < 0.05) improved the digestibility of crude protein and energy. Dry matter digestibility of the rye-based diets was unaffected by treatment. Key words: Swine, rye, barley, beta-glucanase, pentosanase, salinomycin
Effects of periodic feeding of diets containing ochratoxin A on the performance and clinical chemistry of pigs from 15 to 50 kg body weight
Authors: Lippold C. C. , Stothers S. C. , Frohlich A. A. , Boila R. J. , Marquardt R. R.
Published: March 2010

Diets containing zero (0), low (L) or high (H) concentrations of ochratoxin A (OA), 0.0, 0.5 and 2.5 mg kg−1 diet, respectively, were fed to barrows of initial body weight 14.8 kg (SD = 1.49) over three successive periods, each of 21-d duration. The four treatment combinations (TC1 to TC4) were the feeding of diets that differed in OA content in Periods 1 and 2, respectively, 0 and 0 diets for TC1, 0 and H diets for TC2, L and 0 diets for TC3, and L and H diets for TC4. An OA-free diet (0) was fed to all animals in Period 3. Average daily gain was lower with L (P < 0.05) and H (P < 0.01) diets compared to the 0 diet. Feed intake was lower (P < 0.05) and feed efficiency was poorer (P < 0.01) with the H compared to the 0 diet. A change in kidney function was indicated with OA in both L and H diets: (1) hyperproteinemia (P < 0.05, L and H diets), without (P > 0.05) a change in serum albumin; and (2) azotemia, a higher serum urea (P < 0.05, L diet) and creatinine (P < 0.01, L and H diets). Hypocholesterolemia and hypercalcemia were noted (P < 0.01) with the H compared to the 0 diet. The TC2 pigs recovered with a higher than normal average daily gain in Period 3 after 21 d of dietary OA in Period 2; however, the requirement for Zn and (or) P may differ after this exposure to OA. For TC4 pigs, a low serum albumin after Period 3 was indicative of a residual kidney damage after 42 d of dietary OA in Periods 1 and 2. The results suggest that pigs weighing 15 to 24 kg did not adapt to OA when a sequence of L diet followed by H diet was fed during successive 21-d periods. Key words: Pigs, ochratoxin A, growth, serum chemistry
Effective rewarming of hypothermie piglets using 915-MHz microwaves
Authors: Bate L. A. , Crossley J. G. , Wade R.
Published: March 2010

A prototype 915-MHz microwave unit was designed to rewarm hypothermic piglets. Initial tests indicate that it is possible to rewarm piglets successfully from deep stages of hypothermia using 915-MHz microwaves. Rewarming did not cause any significant physiological changes in blood variables, nor did the animals show any visible change while their subsequent behaviour appeared normal. Key words: Piglets, hypothermia, microwave, rewarming
A study on the prevalence of cracked claws among beef cows
Authors: Hand R. K. , Goonewardene L. A. , Yaremcio B. J. , Westra R.
Published: March 2010

A survey of the prevalence of vertical (sand) cracks on claws of cows on pasture in northwest Alberta found 261 out of 1183 or 22.7% cows affected. Among cows with cracks, 62% had a single crack while 29% had two cracks. There were significantly (P = 0.00001) more cracks on the outside (80.6%) compared with the inside (19.4%) claw. Significantly (P = 0.0002) more of the severe cracks were found on the outside claw. Key words: Claw, cracks, cows, severity, prevalence