bluuebunny/crossref_metadata_2025 huggingface dataset:
Reproductive efficiency of F1 and reciprocal backcross beef cows under contrasting 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

A population of 860 F1 and reciprocal backcross females representing Hereford (H), Angus (A), Shorthorn (N), Charolais (C) and Simmental (S) breeding were evaluated for reproductive efficiency under two contrasting environments (Brandon, Manitoba and Manyberries, Alberta). The F1 included the HA, CN and SN and the reciprocal back-crosses were HCH, CCH, ACA, CCA, HSH, SSH, ASA, SSA, NSN, SSN, NCN and CCN. All females were bred to Limousin bulls. The data collected from 1980 to 1986 comprised 3108 mating opportunities and 2523 pregnancies. For dam crosses common to both locations (HA, SN and specific dam crosses involving S) differences in performance criteria occurred with females at Manyberries recording greater cow losses, higher conception and weaning rates, and more weight of calf weaned than at Brandon. Combining these performance elements gave the females at Manyberries an advantage for weight of calf weaned per mating opportunity (162 ± 3.2 vs. 152 ± 3.0 kg). Barren culls comprised the largest proportion of cow losses at both locations with HA and NSN greatest and ASA lowest at Brandon, and SSH greatest and SN lowest at Manyberries, all significant at P ≤ 0.05. None of the differences for C cross females was significant (P > 0.05). Weaning rates per mating opportunity for dam crosses common to both locations indicated the ASA highest and the SSH lowest at both locations, the difference being 22.9% at Brandon and 13.2% at Manyberries. For the HA, CN and C backcross comparisons, the highest weaning rate per mating opportunity was recorded for the HA (73.3%) and the lowest for the CCA dam cross (62.4%). At both locations, the SN dams produced the most weight of calf weaned per mating opportunity with the lowest values recorded by the HA and NSN dam cross at Brandon and the HSH dam cross at Manyberries with the CN dam cross recording the highest values and the CCA and ACA the lowest. For all performance criteria calves out of F1 dams had an advantage over calves from backcross dams. Key words: Beef cattle, cow productivity, crossbreeding
A survey of marbling fat in Canadian beef carcasses
Authors: Jones S. D. M. , Tong A. K. W. , Talbot S.
Published: March 2010

Marbling score was assessed in 20 437 Canadian beef carcasses on a 10-point scale (1 = very abundant, 10 = devoid) in six provinces during the period August to November 1989. Heifer carcasses had a lower marbling score (more marbling fat) than steer carcasses, and both had lower marbling scores (more marbling fat) than bull carcasses. Marbling increased as Canada grade changed from B1 to A1 and from A1 through to A4, indicating that marbling fat increased with carcass fatness. The regression of marbling score on carcass weight and carcass 12th rib fat thickness, although significant, showed that these traits only accounted for 0.5 and 6%, respectively, of the overall variation in marbling score. The overall distribution of marbling scores showed that 20.6% of carcasses had small or more marbling, 57.9% had slight marbling, 20.4% had traces of marbling and 1.1% were devoid of marbling. Key words: Beef, carcass, marbling, survey
Comparative effects of feeding and duodenal infusion of monensin on digestion in sheep
Authors: Rogers Michaela , Jouany J. P. , Thivend P. , Fontenot J. P.
Published: March 2010

The effect of monensin on digestion was compared when it was used as feed additive or infused into the duodenum. Six Texel wethers fitted with ruminal, simple duodenal and re-entrant ileal cannulae, divided into three groups, were fed a mixed diet alone (control) or with 33 mg of monensin in feed or infused through the duodenal cannula. The experiment was designed as a 3 × 3 Latin square. Feeding monensin increased (P < 0.05) the amount of OM digested in the rumen and small intestine; infusion into the duodenum had no effect on this parameter. Monensin had no effect on the extent or site of N digestion. No ruminal recycling of monensin was observed since ruminal VFAs were not altered by monensin infusion into the duodenum. VFAs in the hindgut were only modified when monensin was fed (improvement of propionate proportion, P < 0.05). Amylase activity remained unchanged in the intestine whatever the monensin supply. Only fed monensin increased (P < 0.05) trypsin activity. Infused monensin increased the plasma glucose level (P < 0.05), which indicates that monensin has metabolic effects. These results show that the intestine is not the major target for monensin when it is used as a growth promoter in ruminants. Key words: Monensin, intestinal digestion, plasma glucose, sheep, VFA, nigrogen
Forage conservation in round bales or silage bags: effect on ensiling characteristics and animal performance
Authors: Nicholson J. W. G. , McQueen R. E. , Charmley E. , Bush R. S.
Published: March 2010

In the first of two experiments to determine the ensiling characteristics of big bale silage, forage was ensiled in round bales (1.2 m diameter × 1.2 m length) at 350–400 (wetter) or 450–500 (drier) g kg−1 dry matter (DM) content by wrapping in plastic. Initial fermentation was more rapid in the wetter bales, as shown by a more rapid and extensive drop in pH and increase in concentration of lactic and acetic acids. The initial lactic acid bacteria (LAB) log counts ranged from 105 and 107 units and were higher for the wetter bales through day 9. By day 58, counts had declined and there were no differences due to moisture level. Water soluble carbohydrate content was higher (P < 0.01) for the drier bales. Ammonia N was higher (P < 0.01) in the wetter bales. Non-protein nitrogen (NPN) did not differ (P > 0.05) due to moisture level at day 9 or day 58. In the second experiment, bales ensiled at (mean ± SE) 390 ± 90 g kg−1 DM content (bale silage) were compared for ensiling characteristics and nutritive value with similar forage chopped and packed in a plastic bag (bag silage). The bag silage had a faster and more extensive drop in pH and increase in concentrations of lactic and acetic acids. Temperatures were approximately 6 °C higher in the bag than in the bale silages over the first 30 d. LAB counts increased faster in the bag silage and then declined and were lower (P < 0.05) than in the bale silage at day 60. Clostridia counts were low in the bag silage and in some bales but exceeded 106 viable spores in other bales. There were no differences between the two silages in digestibility by sheep. However, beef calves fed the bag silage gained more weight with better feed efficiency than those fed bale silage (P < 0.01). Calves fed the bale silage responded to protein (soybean meal) supplementation with increased gain and improved feed conversion, but there was no response with the bag silage. The bag silage had, on average, less NPN (468 vs. 585 g kg−1 total N) than the bale silage. Key words: Silage, big round bales, bag, protein supplementation, cattle performance
Reproductive performance, growth rate and body composition of broiler breeder hens differing in body weight at 21 weeks of age
Authors: Robinson F. E. , Robinson N. A.
Published: March 2010

The effects of variation in body weight at 21 weeks of age on subsequent growth rate, body composition and reproductive performance were studied in broiler breeder hens from 22 to 62 weeks of age. Pullets were sorted into three groups on the basis of body weight (low, medium and high) at 21 weeks of age. Pullets of the low-weight group contained a greater percentage of carcass water and less carcass fat at 22 weeks of age than did the medium- and high-weight pullets, and less carcass protein than the high-weight birds. The relative difference in body weight between the three groups of hens was maintained to 62 weeks of age, the high-weight hens being heavier than the low- and medium-weight hens at the end of the study. The low-weight birds began to lay later than the medium- and high-weight pullets. The low- and medium-weight birds were lighter in weight compared to the high-weight pullets at sexual maturity. Total egg output was lower in the low-weight hens than in the medium- and high-weight hens. No difference was seen in sequence and intersequence pause parameters or in fertility, embryo viability or embryo production between the three groups of hens. On a percentage basis, there were no differences in body composition between groups of birds at 62 weeks of age. It was concluded that pullets which are underweight at 21 weeks of age exhibit a poorer production record than do pen-mates which are of normal or greater than normal body weight. Key words: Broiler breeder hens, egg production, body weight, body composition, sequence length, fertility, embryo viability
Studies on dehorning steers in Alberta feedlots
Authors: Goonewardene L. A. , Hand R. K.
Published: March 2010

The study contained 507 crossbred steers from seven lots in five owner-operated feedlots. The objective was to determine the effects of dehorning (DH) at the feedlot on growth rate, compared to a control (CO) consisting of polled or previously dehorned steers. Significant (P < 0.01) treatment differences (DH = 1.11 ± 0.01 kg d−1, CO = 1.16 ± 0.01 kg d−1) and treatment × lot interaction were observed for average daily gain from 0 to 106 d. Key words: Dehorning, steers, feedlot, gain
Follicular steroidogenesis in vitro in cyclic and PMSG/hCG-treated gilts
Authors: Wiesak T. , Hardin R. T. , Foxcroft G. R. , Hunter M. G.
Published: March 2010

Basal steroid production in vitro by comparable follicles from cyclic and PMSG/hCG-treated gilts was similar. Follicular responses to LH in vitro varied, however, confirming earlier evidence for functional differences in the pattern of follicular development in immature gilts in response to exogenous gonadotropins compared with naturally cyclic gilts. Key words: Pig, gonadotrophin, follicle, steroidogenesis, steroids
Thiamin supplementation of beef cattle diets
Authors: Hironaka R. , Kozub G. C.
Published: March 2010

Thiamin supplementation at 10 mg kg−1 of barley-based all-concentrate diets fed to slow- or fast-gaining 250-kg steers or of diets with 10.9 or 11.8% crude protein did not increase rate of gain. The thiamin pyrophosphate (TPP) effect was lower in supplemented than in non-supplemented steers (P < 0.05), indicating that supplementation increased the thiamin level in the blood. Key words: Steers, thiamin, TPP effect
Colostrum intake by newborn piglets
Authors: Fraser David , Rushen Jeffrey
Published: March 2010

Colostrum intake by newborn piglets was studied by weighing piglets every 10 min for their first 1–4 h with the sow, and their cumulative weight increases were used as estimates of colostrum intake. In seven litters, four piglets were monitored for 4 h beginning about 2 h after the birth of the first piglet in order to determine if colostrum is available continuously or released in discrete ejections. There was little synchrony between litter-mates in their intake in the first hour, but by the second hour of monitoring (starting about 3 h after farrowing began), much of the colostrum was released in discrete ejections and piglets achieved most of their intake during the few 10-min intervals when an ejection occurred. To examine the effect of birth sequence, four piglets were added to the udder each hour for 3 consecutive hours. Piglets added in the last hour showed a small but significant tendency (P < 0.05) to obtain less colostrum than those added in the middle of the sequence. In nine litters, three piglets were confined to posterior and three to anterior teats for 1.5 h to examine the effect of teat position. Those on posterior teats had slightly but significantly (P = 0.02) lower estimated intake than piglets on anterior teats. Although low-birth-weight piglets, late-born piglets, and piglets sucking only posterior teats tended to obtain less colostrum, the differences were small, and most piglets obtained an amount of colostrum consistent with normal serum immunoglobulin concentration. Key words: Piglet, colostrum, suckling behavior, milk ejection, parturition
Effects of Synchro-Mate B and prostaglandin F2α on estrus synchronization and fertility in beef cattle
Authors: Twagiramungu H. , Dufour J. J. , Guilbault L. A. , Proulx J.
Published: March 2010

The efficiency and precision of estrus synchronization and fertility were evaluated after prostaglandin F2α (PGF) treatment with or without pretreatment with Synchro-Mate B (SMB) in beef cattle. In the treatment group (SMB-PGF, n = 109), postpartum suckled (n = 53), and nonsuckled (n = 32) cows and virgin heifers (n = 24) received SMB for 9 d and PGF 72 h before implant withdrawal. In the control group (Control, n = 111), postpartum suckled (n = 51), and nonsuckled (n = 36) cows and virgin heifers (n = 24) were observed for estrus and bred at spontaneous estrus over a 6-d period. Those not detected in estrus were then injected with PGF and bred at induced estrus over an additional 6-d period. Synchronization rate at induced estrus was higher (95.4 vs. 84.2%, P < 0.01) and time interval from induction to onset of estrus was shorter (37.0 ± 2.1 h vs. 56.7 ± 2.8 h, P < 0.01) in the SMB-PGF group than after PGF in the Control group. Whether the time around the mean interval to estrus (precision) was ± 6, ± 12, ± 18 or ± 24 h, the synchronization rate was always higher (P < 0.01) in the SMB-PGF than in the Control group. Heifers and cows in both groups had similar estrus synchronization rates and mean intervals to estrus. Suckled and nonsuckled cows behaved similarly in their estrus response within the SMB-PGF group but not in the Control group. Our results indicate that administration of PGF 72 h before SMB implant withdrawal could be a very efficient and precise synchronization method without a negative effect on fertility in beef cattle. Key words: Estrus synchronization, beef cattle, Synchro-Mate B, prostaglandin F2α
Effect of Ca-EDTA on performance, blood parameters and muscle color of grain-fed Holstein veal calves
Authors: Pommier Serge A. , Vinet Claire , Lachance Bertrand
Published: March 2010

Sixty-four grain-fed male Holstein veal calves were allotted to treatments and were fed three levels of the calcium chelate of the disodium salt of ethylenediaminetetraacetic acid (Ca-EDTA) in their diet (0 mg, 30 mg and 60 mg of Ca-EDTA mg−1 of dietary Fe) for two time periods prior to slaughter (4 and 8 wk). Carcasses were then allotted to one of two cooling rates (slow and fast). Neither level of Ca-EDTA nor time period affected feed intake, ADG or feed efficiency. Regardless of time of application, the chelating agent significantly (P < 0.01) reduced serum Fe concentrations within 1 wk of initiation of treatment and blood haemoglobin concentrations within 2 wk of initiation of treatment. Liver Fe concentrations were significantly reduced (P < 0.05) and liver Cu concentrations were significantly (P < 0.01) increased by both levels of Ca-EDTA. The digestibility of feed DM or N was not significantly (P > 0.05) affected by treatments. The inclusion of Ca-EDTA for 8 wk prior to slaughter significantly (P < 0.05) lightened the color of the pectoralis. However, no significant dose response between the 30-mg and 60-mg treatments was observed. Compared to controls, the 4-wk treatment was not effective in improving the color of the meat. The fast cooling rate significantly (P < 0.05) lightened the appearance of the pectoralis muscle. In conclusion, EDTA effectively lightened muscle color without affecting animal performance. Key words: Veal, grain, EDTA, digestibility, chelator, color
Effect of extrusion on ruminal and intestinal disappearance of amino acids in white lupin seed
Authors: Cros P. , Moncoulon R. , Bayourthe C. , Vernay M.
Published: March 2010

The effect of extruding white lupin seed (WLS) at 120 or 150 °C on the degradability of crude protein in the rumen and the intestine of nonlactating Holstein cows was determined in situ. Nylon bags were incubated in the rumen for 16 h and then introduced into the small intestine, through a duodenal cannula, for subsequent recovery in feces. Extrusion of WLS at 120 or 150 °C decreased the degradability of crude protein in the rumen (86.9–73.6 vs. 98.4%) and increased the amount of crude protein disappearing in the intestine (11.8–25.0 vs. 0.8%). Extrusion did not alter the amino acid (AA) profile of WLS, although the AA composition of the WLS protein that escaped ruminal digestion differed markedly both quantitatively and qualitatively, from its initial composition. Extruding WLS increased intestinal disappearance of most of the AA, but variation in disappearance among AA was substantial. Thus, WLS proteins that are not degraded in the rumen differ in their potential as a source of absorbable AA in the intestine from the original source. Comparison of essential AA profiles of original sources to that of milk indicated that the sulphur AA were first-limiting in WLS, with valine, lysine and leucine being second through fourth limiting. The estimated AA chemical score (test-to-milk ratio) for original WLS was 64%. For the rumen undegraded protein fractions disappearing in the intestine, the limiting AAs in descending order were: sulphur AA, valine, phenylalanine plus tyrosine and threonine for raw WLS; sulphur AA, lysine, valine and histidine for WLS extruded at 120 °C and lysine, valine, histidine and sulphur AA for WLS treated at 150 °C. The corresponding AA chemical scores were: 63, 76 and 72%. Consequently, after extrusion, the ruminally undegraded protein of WLS that disappeared in the intestine showed a higher protein quality. Key words: Cow, lupin, seed, amino acids, extrusion, ruminal degradation, intestinal disappearance
The effect of dietary enzyme supplementation of rye- and barley-based diets on digestion and subsequent performance in weanling pigs
Authors: Patience J. F. , Bedford M. R. , Classen H. L. , Inborr J.
Published: March 2010

Two experiments were conducted to determine the effect of xylanase (850 U g−1) supplementation of a rye and soybean meal-based diet (exp. 1) and β-glucanase (1086 U g−1) supplementation of a barley- and soybean-meal-based diet (exp. 2) on the progress of protein and starch digestion throughout the small intestine. In each experiment, 12 weanling pigs per treatment were fed the experimental diet for a 10-d period, at the end of which feed intake and weight gain were recorded and samples of digesta were collected from the small intestine, colon and rectum. Xylanase supplementation did not result in any improvement in rate or efficiency of gain, feed intake, starch or protein digestibility (P > 0.05). Digesta viscosity was increased by enzyme supplementation in some sections of the small intestine. β-glucanase supplementation resulted in a significant (P < 0.05) increase in rate of gain and improved protein digestibility in the colon and in the last three-quarters of the small intestine, but had no effect on starch digestibility. In conclusion, β-glucanase supplementation of barley/SBM-based diets for young weanling pigs was of benefit whereas pentosanase supplementation of rye/SBM-based diets was not. Key words: Swine, pentosanase, β-glucanase, digestion, barley, rye
A preliminary examination of potential interactions between deoxynivalenol (DON) and other selected Fusarium metabolites in growing pigs
Authors: Rotter R. G. , Trenholm H. L. , Prelusky D. B. , Hartin K. E. , Thompson B. K. , Miller J. D.
Published: March 2010

The performance of growing pigs fed 2 mg kg−1 of one of several Fusarium graminearum metabolites (sambucinol, 15-acetyldeoxynivalenol, 3-acetyldeoxynivalenol, culmorin, dihydroxycalonectrin) with and without 6 mg kg−1 deoxynivalenol (DON) was examined in three preliminary studies. The only significant effects (P < 0.05) were seen in feed consumption, weight gain and feed efficiency due to the presence of DON in the diet. In addition, the appearance and degree of folding of the esophageal portion of the stomach were also different between pigs fed the DON-free and DON-contaminated diets, though the degree of significance varied between trials. Some small differences were seen in growth and feed consumption for certain metabolites, notably sambucinol and culmorin, with and without DON, but they were not significant (P > 0.05). The data indicate that, at the dietary concentrations used, the fungal metabolites tested in combination with DON do not interact with DON in growing pigs to any marked degree. Key words: Deoxynivalenol, DON, pigs, 15-acetyldeoxynivalenol, 3-acetyldeoxynivalenol, culmorin, sambucinol, dihydroxycalonectrin
Sulphur and calcium supplementation of soybean and canola meal diets
Authors: Summers J. D. , Bedford M. , Spratt D.
Published: March 2010

No significant difference in weight gain or feed:gain ratio was noted with 6-wk-old male broilers fed a practical type corn-soybean meal diet or a similar diet containing 25% canola meal. Supplementing the canola meal diet with 0.2% sulphur, however, did significantly reduce gain. A reduction in feed intake and total abdominal fat was noted with the canola-meal-supplemented diets as compared to the corn-soybean meal diets. In a second experiment, sulphur addition to a soybean meal, semi-purified, low-protein, low-calcium diet, resulted in weight gains and feed intakes similar to those noted in a canola meal diet with the same levels of sulphur fed to male broilers from 7 to 21 d of age. As sulphur was added to the soybean meal diet, there was a linear depression in weight gain and feed intake which was partially overcome by calcium supplementation. Sulphur appeared to exert its negative effect on performance by reducing feed intake rather than interfering with the efficiency of utilization of the diets. The present results suggest that high levels of inorganic sulphur in canola meal are a major factor in the reduced performance often reported with canola-meal-supplemented diets. Key words: Chickens, canola, sulphur, calcium, feed intake
Genetic evaluation of Canadian dairy bulls for milking speed with an animal model
Authors: Banos G. , Burnside E. B.
Published: March 2010

Bull proofs for milking speed were computed under an animal model for five dairy breeds. Data were subjective scores on first lactation cows from all milk recording agencies across Canada. There were 1411 Holstein, 171 Ayrshire, 85 Jersey, 31 Guernsey, and 17 Brown Swiss bulls that received official evaluations. Bull proofs were expressed on a linear scale from 1 to 9, where 9 designated bulls with the fastest milking daughters. The biological significance of these proofs was investigated using 6965 weekly cow records of total milking time, average flow rate, and peak flow. Data were on 119 Holstein cows by 41 officially proven sires. Increases in proofs of 1 point on the linear scale were associated with decreases in total milking time of 20 s and increases of 64 g min−1 and 140 g in average and peak flow, respectively. Key words: Milking speed, animal model, national evaluation, dairy bulls
Colostrum and milk composition of sows immunized against somatostatin or its carrier protein
Authors: Farmer C. , Brazeau P.
Published: March 2010

Colostrum and milk composition were determined in sows immunized against somatostatin (SRIF-IMM, n = 9) or its carrier protein (BSA-IMM, n = 8). Immunization against somatostatin (SRIF) did not alter milk composition but many components of mammary secretions were affected by the stage of lactation. It was concluded that SRIF-IMM has no beneficial effect on colostrum or milk composition in sows. Key words: Sow, immunization, somatostatin, milk
Genetic parameters of the duration of fertility in hens
Authors: Beaumont Catherine
Published: March 2010

After two successive artificial inseminations (AI) with 125 × 106 spermatozoa, various characteristics of the duration of fertility were observed in 2375 egg-type hens at 33 and 44 wk of age: number of fertile (F) or hatched (H) eggs during a 21-d control period after AI, early, medium or late embryonic mortalities occurring at the same time and efficient (De) and maximum (Dm) duration (i.e. time between AI and the first clear egg or the last fertile egg, respectively). Heritability estimates of F, H, De or Dm ranged from 0.08 to 0.31. All genetic correlations between these variables (measured at the same age) were high (0.45–0.99) as well as those between the same variable measured at different ages (0.30–0.97). Estimates of genetic parameters varied little when estimated by Henderson's method III or REML but with the second method only all estimates were within the parameter space. A Box-Cox transformation of data slightly modified heritability estimates and animal ranking after genetic evaluation. The best criterion of selection for duration of fertility seems to be H as it is economically important, well heritable and highly correlated with the other characteristics of duration of fertility. Key words: Genetic parameters, fertility, poultry, Restricted Maximum Likelihood
Effect of length of cut on quality of stack silage and milk production
Authors: Savoie P. , Flipot P. M. , Tremblay D. , Thériault R. , Tremblay G. F. , Wauthy J.-M.
Published: March 2010

Wilted grass at moisture contents ranging between 62 and 76% was chopped at 6.3, 12.7, 25.4 and 38.1 mm theoretical length of cut (TLC) and conserved in large stack silos during 2 consecutive years (1986, 1987). Average real lengths of cut were 11, 21, 37 and 47 mm for the four TLC, respectively. Dry matter losses in the silos containing forage cut at 12.7 and 25.4 mm TLC (15.6 and 16.2%, respectively) were higher (P = 0.016) than losses in the silos containing forage cut at 6.3 and 38.1 mm TLC (12.1 and 12.9%, respectively). Within the range of TLC used, there was no evidence of improved silage quality to favor shorter chop length in stack silos. In both years, silage of each TLC was mixed with high-moisture barley and protein supplement and fed to a group of 16 dairy cows. There was no consistent effect of TLC on dry matter intake. The shortest length produced slightly more milk which was offset by a slightly lower percentage of milk fat. A TLC of 6.3–38.1 mm is adequate for silage fed to dairy cows producing between 20 and 28 kg of milk per day. Key words: Particle length, stack silos, silage, grass, dairy
The effect of thickness of steam-rolled barley on its utilization by beef cattle
Authors: Hironaka R. , Beauchemin K. A. , Lysyk T. J.
Published: March 2010

All-concentrate diets consisting of thin-, medium- or coarse-rolled barley or whole barley were fed to 24 Hereford steers and 24 Hereford bulls. Digestibility trials and chewing studies were conducted on each of the diets. Cattle fed medium-rolled barley gained faster (P < 0.05) (1.62 kg d−1) than those fed thin-rolled (1.49 kg d−1) or whole barley (1.38 kg d−1), and cattle fed coarse-rolled barley gained faster (P < 0.05) (1.53 kg d−1) than those fed whole barley. The average daily gain was similar in cattle fed thin-rolled and whole barley. Feed intake was lower from week 2 to week 8 in cattle fed the thin- and medium-rolled barley diets than in those fed the coarse-rolled and whole-barley diets. Gain-to-feed ratio decreased as the thickness of the roll increased and was lowest in cattle fed whole barley. Energy, protein and starch digestibilities declined with thickness of roll and were lowest for the whole-barley diets. Ruminating time and the time ruminating per kilogram of feed increased as the thickness of the roll increased; rumination time was longest on the whole-barley diet. Key words: Beef cattle, barley, rolling, processing, rumination, digestibility
Effect of formaldehyde-treated barley or escape protein on nutrient digestibility, growth and carcass traits of feedlot lambs
Authors: McAllister T. A. , Beauchemin K. A. , McClelland L. A. , Cheng K.-J.
Published: March 2010

One hundred and three lambs were fed three isonitrogenous diets: formaldehyde-treated barley (0.11% wt wt−1) with canola meal; untreated barley with corn distillers' grain and fishmeal (escape protein); and untreated barley with canola meal (control). Formaldehyde treatment did not affect ADG, whereas escape protein increased (P < 0.05) ADG of lambs by 5.3%. Carcass traits of lambs from all diets were similar, although kidney fat was reduced (P < 0.05) in lambs fed formaldehyde-treated barley. A digestibility trial with six lambs (32.6 ± 2.4 kg) showed that DM intake and digestion of DM, organic matter, nitrogen and starch were similar among diets. DE was 3.8% lower (P < 0.05) for the formaldehyde-treated diet than the mean of the other two diets. ME was 5.4% lower (P < 0.07) for the formaldehyde-treated barley than for the control diet. Digestion of NDF was 7.3% higher (P < 0.07) in the escape protein diet compared with the control diet. Treatment of barley with 0.11% (wt wt−1) formaldehyde lowered the DE of barley and did not increase the growth rate or improve the feed efficiency of feedlot lambs. Key words: Sheep, escape protein, fishmeal, formaldehyde, barley
Effect of plane of nutrition between 6 and 16 months of age on body composition, plasma hormone concentrations and first-lactation milk production in Holstein heifers
Authors: Stelwagen K. , Grieve D. G.
Published: March 2010

In a completely randomized design, 47 dairy heifers (6–8 mo of age) were assigned to a low (L), medium (M) or high (H) plane of nutrition to determine its effect on body composition (Slaughter Group, n = 23), subsequent first lactation (260 d) milk production (Production Group, n = 24) and blood somatotropin and insulin concentrations (n = 12 from each Slaughter and Production group). Actual daily gains between 6 and 16 mo of age were 611 g (L), 737 g (M) and 903 g (H). The proportion of carcass fat in heifers sacrificed at 16 mo increased while the proportion of lean and bone tissue decreased with increasing plane of nutrition. Concentrations of somatotropin measured at 9 and 14 mo of age decreased but insulin did not differ (9 mo) or tended (P < 0.10) to increase (14 mo) with increasing feeding level. Insulin concentrations at 9 and 14 mo of age were correlated positively with mammary crude protein and dry fat-free tissue at slaughter (9 mo, P < 0.05; 14 mo, P < 0.07), implying that insulin may play a role in mammogenesis in vivo. Plane of nutrition during the rearing period did not significantly affect production and composition of milk in the first lactation. It is speculated that this may be due to the fact that the heifers weighed approximately 200 kg at the start of the experiment, because recent research has demonstrated that the critical weight range during which mammary gland development is affected by plane of nutrition is between 90 and 200 kg. Key words: Heifer, somatotropin, insulin, lactation, plane of nutrition, body composition
Usefulness of pedigree indices in predicting future transmitting abilities of sons
Authors: Ali T. E. , Schaeffer L. R. , Gibson J. P. , Burnside E. B.
Published: March 2010

Two thousand three hundred and five bulls with complete pedigree information and proofs (ETA) in at least 1 of 10 yr for milk, fat and fat percent were used to study the reliability of genetic evaluations. No evidence was found that bulls with superior genetic evaluations failed to pass on this superiority to their sons and maternal grandsons. The assumption that all the genes controlling these quantitative traits are autosomes seems to be reasonable. Key words: Dairy cattle, genetic evaluation, bias
Influence of somatotropin treatment of lactating cows on maintenance energy expenditures
Authors: McBride B. W. , Burton J. H. , MacLeod G. K. , Early R. J.
Published: March 2010

The maintenance energy expenditure associated with Na+, K+-transport and protein synthesis within skeletal muscle was determined for rbST-treated and untreated cows. Somatotropin had no effect on elevating the respiration of skeletal muscle or the partitioning of maintenance energy expenditures within skeletal muscle. Key words: O2 consumption, somatotropin, Na+, K+-ATPase, protein synthesis
Liveweight gain by beef calves grazing cool-season annual grass in the spring and supplemented with grass hays
Authors: Hubbell D. S. , Harrison K. F. , Goetsch A. L. , Galloway Sr. D. L. , Forster Jr. L. A. , Li F. , West C. P. , Johnson Z. B. , Patil A. , Sun W.
Published: March 2010

Supplementing beef calves grazing cool-season annual grass with warm- or cool-season grass hay (0.4% liveweight), differing in cell wall content, depressed weight gain more by heifers than steers. Adding supplemental corn (0.8% liveweight) to hay only improved gain by heifers, though gain was not greater than controls for either gender. Key words: Cattle, beef, supplements, pasture, corn, hay
The response of broiler turkeys to Flavomycin
Authors: Caston L. J. , Leeson S.
Published: March 2010

A trial was conducted to note the general response of Medium White broiler turkeys to diets containing 2 ppm Flavomycin. Only male turkeys were consistently heavier in response to Flavomycin. Body weight responses correlated with feed intake. Adding Flavomycin to the diet had no effect on feed efficiency or mortality to 84 d of age. Key words: Flavomycin, turkey broiler
The effects of gender and blast-chilling time and temperature on cooking properties and palatability of pork longissimus muscle
Authors: Jeremiah L. E. , Jones S. D. M. , Tong A. K. W. , Kruger G. , Gibson R.
Published: March 2010

Fifty Yorkshire gilts and 39 Yorkshire barrows were utilized to evaluate the effects of gender and blast-chilling time on the cooking properties and palatability of pork. Barrows had a more intense flavor than gilts (P < 0.05), but this difference was not of sufficient magnitude to be of practical importance. Samples blast chilled for 1 h were more tender initially and overall and were rated higher in overall palatability than samples blast chilled for 2 or 3 h. However, the magnitude of these differences limit their practical significance; and the palatability of sides subjected to extremes of blast chilling (3 h, −40 °C) did not differ meaningfully from that of conventionally chilled sides. The composite results indicate that blast chilling can effectively reduce carcass shrinkage and improve meat quality, regardless of gender, without adversely affecting palatability or cooking properties within the context of the conditions of the present study. Key words: Pork, gender, blast chilling, palatability, cooking properties
Protein supplements for corn-silage diets and their effect on subsequent growth and carcass characteristics in beef cattle
Authors: Horton G. M. J. , Pitman W. D. , Pate F. M.
Published: March 2010

Ninety-six Brahman crossbred steers (187 ± 3.9 kg) were used to evaluate protein supplements in corn-silage growing diets for 140 d. The following treatments were used: 1, control (7.9% crude protein (CP)); 2, urea (10.3% CP); 3, dehydrated alfalfa (10.0% CP); or 4, soybean meal (SBM) (10.6% CP). Steers were then fed a common finishing diet (80% corn) with 13.4% CP for 120 d. Steers fed the control diet had lower levels of plasma-urea nitrogen, consumed less feed, gained less weight and utilized feed less efficiently than those fed supplemented diets (P < 0.05). Steers fed SBM gained weight faster than those fed urea (P < 0.05), though feed/gain ratios were similar. Although control steers exhibited compensatory growth during the 120-d finishing period, re-alimentation was not complete, and their overall gain was lowest at the end of the 260-d study (P < 0.05). Cattle fed the low-protein growing diet also had lighter carcasses, smaller loin eye area and less backfat and marbling than steers fed protein supplements (P < 0.05). Carcass characteristics were similar for the three protein supplements. These results demonstrate that urea equalled SBM and dehydrated alfalfa as a protein source in a corn-silage growing diet as measured by overall performance and carcass characteristics at the end of 120 d re-alimentation on a finishing diet. However, the negative effects of protein deprivation during the 140-d growing period were not completely overcome after a 120-d finishing period. Key words: Compensatory growth, protein supplements, carcass, beef cattle
Digestible energy requirements for growth in Hereford and Charolais × Hereford steers
Authors: Kozub G. C. , Hironaka R.
Published: March 2010

The relationship between digestible energy intake (DEI) per day and growth in steers was investigated using data from 717 steers fed individually in several experiments. Regression equations relating DEI, gain and weight were obtained for medium-frame (Hereford) and large-frame (Charolais × Hereford) steers that had been fed all-concentrate or hay–concentrate diets under various feeding regimes from weaning to slaughter. The equations can be used as a guide for estimating DEI and gain and provide information on the efficiency of feed utilization. Estimates of the mean DEI for a given mean gain and weight of steers in a large commercial feedlot operation were similar to the observed mean DEI. Steers restricted in DEI for the first 24 wk of the feeding period (average initial weight of 213 and 257 kg for Hereford and Charolais × Hereford, respectively) generally utilized DE more efficiently than steers fed to appetite on a concentrate or hay–concentrate diet, but as market weight was approached, restricted steers required more DE for a given gain and weight than steers fed on concentrate ad libitum. Efficiency of DE utilization was lower when steers were at low weights and as they approached market weight. Key words: Steers, DE requirement, frame size
The scientific assessment of the impact of housing on animal welfare: A critical review
Authors: Rushen Jeffrey , Passillé Anne Marie B. de
Published: March 2010

The issue of animal welfare, particularly in relation to legislation, involves philosophical, ethical, economic and political issues and is not just a matter for science. A scientific definition of welfare must address the concerns of the public, but is difficult to achieve because of a lack of consensus as to what good welfare involves. The assessment of animal welfare is best achieved using a mixture of design criteria (which specify what must be included in the environment) and performance criteria (which specify what the signs of good welfare are). The quality of stockmanship can have a major influence on animal welfare, and it should not be assumed that the method of housing is the major determinant of animal welfare. The validity of many of the proposed measures of welfare is difficult to determine because of a lack of understanding of the underlying biology. Measures of aversion are the best available measures of animal suffering caused by procedures of short duration, but whether they can be used to assess the effect of housing is uncertain. Consensus has not yet been reached on the issue of behavioral deprivation, but several measures of behavioral motivation can be used to determine if animals are frustrated, although none is free from criticism. Much abnormal, stereotyped behavior seems to reflect feeding rather than housing problems, and there is a lack of firm evidence that the level of stereotypic behavior correlates with the welfare of the animals. The method of housing can influence the animals' physiology, but this effect is not adequately described by measures of corticosteroids. Use of the term "stress" generates confusion. Production measures give some information about animal welfare but only if the causes of lowered production are known. Animal welfare is a complex phenomenon and one component of welfare should not be equated with the whole, nor should scientific assessment of welfare be considered a simple matter. Key words: Animal welfare, aversion, motivation, abnormal behavior, stress, stockmanship
The effects of fasting, electrolyte supplementation and electrical stimulation on carcass yield and meat quality in bulls
Authors: Jones S. D. M. , Schaefer A. L. , Tong A. K. W.
Published: March 2010

Eighty-nine yearling beef bulls were allocated to one of four lairage treatment groups of either 0, 12, 24 or 36 h. Except for the 0-h group, all animals were given a 4-h road transport followed by either 12, 24 or 36 h in lairage pre-slaughter without feed and water. An electrolyte solution was offered during lairage to groups of bulls within the fasting treatments. Following slaughter and dressing, alternate carcass sides were stimulated (470 V, 1.5 A, 60 Hz) for 60 s, and data on muscle quality were collected. Fasting resulted in a progressive reduction in warm and cold carcass weight (as a proportion of final live weight) and reduced liver, rumen and intestine proportions. Electrolyte supplementation was effective in reducing carcass weight losses and appeared to have its greatest effect on bulls kept in lairage for 36 h. Fasting and electrolyte supplementation had few effects on muscle quality. Electrical stimulation reduced muscle shear value, lowered final muscle pH, brightened muscle colour at 24 h post mortem but had no effect on marbling score. It was concluded that electrolyte supplementation increased carcass yield in fasted bulls but had little beneficial effect on meat quality. On the other hand, electrical stimulation improved several quality parameters, including muscle shear value. Key words: Bulls, cattle, fasting, lairage, electrical stimulation, meat quality
Effect of lactation feed intake on endocrine status and metabolite levels in sows
Authors: Baidoo S. K. , Lythgoe E. S. , Kirkwood R. N. , Aherne F. X. , Foxcroft G. R.
Published: March 2010

Two experiments were performed to study the endocrine response of sows to changes in feed intake during lactation. The hormonal status of 24 (exp. 1) and 15 (exp. 2) lactating sows subjected to different feed intakes was determined. During a 28-d lactation, the sows were full-fed (FF) or restrict-fed 3 kg d−1 (RF) of a diet formulated to contain 12.4 MJ DE kg−1 and 16% crude protein. On days 2 and 28 postpartum, blood samples were collected by means of indwelling vena cava cannulae from 12 FF and 12 RF (exp. 1) and 8 FF and 7 RF (exp. 2) sows. Metabolic status was assessed by plasma assay for glycerol, free fatty acids, blood urea nitrogen, glucose and creatinine. Endocrine status was determined by plasma assay for growth hormone (GH), insulin, cortisol, prolactin, glucagon, luteinizing hormone (LH) and follicle-stimulating hormone (FSH). On day 2 postpartum, there were no treatment differences (P > 0.05) in plasma concentrations of any of the components studied. On day 28 postpartum, the RF sows had higher (P < 0.05) plasma concentrations of glycerol and creatinine, higher (P < 0.05) concentrations of GH and cortisol and lower (P < 0.05) concentrations of insulin than FF sows. Both mean plasma LH and FSH levels increased (P < 0.05) between days 2 and 28 of lactation. Furthermore, total LH and FSH secretion determined on day 28 was higher in FF than in RF sows (P < 0.05). It is suggested that the hormone changes associated with excessive catabolism in the RF sows during lactation could be functionally related to the difference in gonadotrophin secretion measured at the end of lactation. Key words: Sow, lactation, nutrition, endocrine status
Further enhancement of 3-nitropropanol detoxification by ruminal bacteria in cattle
Authors: Majak W.
Published: March 2010

Ruminal fluid obtained from cattle was used to determine the effects of different diets and supplements on the in vitro degradation of 3-nitropropanol, the miserotoxin aglycone of certain Astragalus species such as timber milkvetch (Leguminosae). Nitroethane, an analog of the aglycone that is much less toxic to mammals, was effective as a supplement when given on alternate days. It enhanced the in vitro rates of nitropropanol degradation in all experiments, by 70–170%. In agreement, daily doses of timber milkvetch at a level equivalent to 3 mg nitropropanol kg−1 body weight also enhanced nitropropanol degradation, suggesting an adaptation to the aliphatic nitro group by ruminal bacteria. The forage protein content appears to contribute to the microbial efficacy and this was verified when diets were supplemented with soybean meal. The protein supplement increased nitropropanol degradation by 37–44% and, as expected, it also promoted cellulose digestion in vitro. The effect of nitroethane supplementation on the absorption of nitropropanol from the rumen was examined when treated and control groups were challenged with timber milkvetch. Plasma levels of 3-nitropropionic acid, the oxidized form of nitropropanol which is detected in the blood, were significantly reduced in response to nitroethane supplementation, and rates of nitropropanol degradation by ruminal microbes were concomitantly enhanced. These combined results further elucidate the factors that control and contribute to nitropropanol detoxification and suggest possible methods of prevention of timber milkvetch poisoning under rangeland conditions. Key words: Timber milkvetch, toxic plant, detoxification, 3-nitropropanol, ruminal bacteria, cattle
Ruminal degradation characteristics of corn and corn–sunflower intercropped silages prepared at two stages of maturity
Authors: Mir Z. , Mir P. S. , Bittman S. , Fisher L. J.
Published: March 2010

The degradation characteristics of dry matter (DM), protein, neutral detergent fiber (NDF) and acid detergent fiber (ADF) of corn–sunflower intercrop silage (CSS) and monoculture corn silage (CS) prepared from whole plants, harvested at two stages of maturity, were compared using eight mature rumen-cannulated steers. The degradation characteristics were determined by incubating the silages in nylon bags for up to 72 h in the rumen of animals fed the respective silages. The degradation characteristics determined for the silages were the soluble fraction, the insoluble but degradable fractions, the rate of degradation of the degradable fractions of silage DM and protein, and the in situ disappearance of NDF and ADF after 0.5 and 72 h of incubation. The rate of particulate passage from the rumen was determined using chromium-mordanted NDF of the four silages. Values were used to estimate effectively degraded DM and protein. The rates of DM and protein degradation were highest for late-cut CSS (6.3 and 6.0% h−1, respectively) and the least for late-cut CS (2.5 and 0.8% h−1, respectively). Averaged across stages of maturity, more (P < 0.05) DM and protein were effectively degraded with CSS (57.4 and 70.1%, respectively) than with CS (48.8 and 48.7%). Degradation of NDF in early-cut CSS was lower (P < 0.05) than in CS after 72 h of incubation. ADF disappearance from all of the silages after 72 h of incubation was similar. Ruminal degradation of DM and protein in CSS was greater than in CS, which may affect efficiency of utilization of CSS. Key words: Degradation rate, effective degradability, corn silage, intercropped corn–sunflower, steers