bluuebunny/crossref_metadata_2025 huggingface dataset:
Gestational and lactational feeding strategies for gilts: Growth, carcass characteristics and meat quality of the progeny
Authors: Fortin A. , Clowes E. J. , Schaefer A. L.
Published: April 2011

This study was conducted to determine whether feeding gilts (1) at or above their National Academy of Sciences-National Research Council (NAS-NRC 1998) requirements during gestation, and (2) to lose a moderate (~10%) or large (~17%) amount of maternal protein during lactation had a residual effect on their progeny’s growth, carcass characteristics and pork quality at market weight. From each litter, the heaviest and lightest barrows and gilts were selected. The progeny of gilts fed above their requirements during gestation, and those that lost the least body protein during lactation were heavier at weaning; +0.3 kg (P < 0.05) and +0.5 kg (P = 0.01), respectively. However, these liveweight differences, which were associated with the gestation and lactation effects, were no longer evident (P > 0.05) at day 35 or 85 post-weaning. But at slaughter, these animals had thinner (P < 0.01) fat thickness and higher (P < 0.05) predicted salable meat yield. Independently of the gestation and lactation treatments, and compared to the low-weaning-weight pigs, the high- weaning-weight pigs maintained their weight advantage (P < 0.01 at day 35 (+ 2.8 kg) and day 85 (+ 5.4 kg) post-weaning), took 4.5 fewer days (P < 0.01) to reach market weight, but had similar (P > 0.05) carcass characteristics and pork quality. Key words: Gilts, gestational and lactational protein, litter, growth, carcass characteristics and meat quality
Relationship between pork muscle fiber diameter and optical transmittance measured by scanning microphotometry
Authors: Swatland H. J.
Published: April 2011

Muscle fibers (n = 50) were isolated from pork psoas minor muscles and mounted in 0.2 M phosphate buffer at pH 5.5 or 7.0. A microscope scanning stage and photometer were used to measure transmittance (T) in relation to fiber diameter, anticipating attenuation of T with increasing diameter. However, T across fibers was often asymmetrical, showing fibers retained flattened sides after being released from bulk meat. A lateral measurement of fiber diameter (89.76 ± 17.07 μm at pH 5.5 and 97.43 ± 20.04 μm at pH 7.0, P > 0.05) was compared with minimum T at any point across a fiber. No T attenuation was detected at pH 7.0 (r = 0.07). At pH 5.5, instead of attenuation, the relationship of T with diameter was positive (r = 0.44, P < 0.05), possibly from differences in myofibrillar composition between small and large diameter fibers (fibrillenstruktur versus felderstruktur). However, attenuation at pH 5.5 was greater than at pH 7.0 (2.76 ± 1.19 vs. 1.42 ± 0.65 ΔT mm-1, respectively, P < 0.001) and was strongly related to wavelength (r = 0.97, P < 0.001). It was concluded fiber shape and fiber-type composition may affect optical properties of bulk meat and myofibrillar refraction may contribute to post-mortem development of normal paleness in pork. Key words: Pork, muscle fibers, paleness
Digestible phosphorus requirement of grower pigs
Authors: Ekpe E. D. , Zijlstra R. T. , Patience J. F.
Published: April 2011

Phosphorus excretion may have a major impact on the environment if it is not managed properly. The success of management strategies for reducing P excretion of pigs is dependent partly on more accurate estimates of P requirements, specifically digestible instead of total P requirements. Performance and metabolism studies were conducted to determine digestible P requirements of grower pigs based on performance, plasma and bone P, and P excretion and retention variables, using 200 pigs (23 ± 0.9 kg) and 20 barrows (54 ± 3.1 kg), respectively. Pigs were fed one of five concentrations of dietary digestible P (0.19, 0.24, 0.33, 0.35, and 0.38%). Increasing digestible P quadratically increased average daily gain (ADG) (P < 0.01), feed intake (P < 0.05), and feed efficiency (P < 0.001). Barrows had a higher ADG than gilts (0.890 vs. 0.838 kg d-1; P < 0.05); however, digestible P requirement was higher for gilts than for barrows (6.92 vs. 6.17 g d-1 or 0.36 vs. 0.32% in diet; P < 0.05). In barrows, increasing digestible P intake quadratically increased P in plasma and urine (P < 0.01), and linearly increased P in faeces (P < 0.01), suggesting that P excretion depends on excess P intake. Using regression analysis, digestible P requirements were 6.45 g d-1 with ADG, 7.46 g d-1 with bone P, 6.01 g d-1 with plasma P, 3.61 g d-1 with urinary P, 5.86 g d-1 with retained P, and 5.11 g d-1 with retained N. Feeding P closer to pig requirements will reduce P excretion. Key words: Phosphorus, requirement, pig
Performance of growing and finishing cattle supplemented with a slow-rlease urea product and urea
Authors: Tedeschi L. O. , Baker M. J. , Ketchen D. J. , Fox D. G.
Published: April 2011

Two growth trials were conducted to study the performance of Angus Crossbred steers supplemented with a slow-release urea product (Optigen® 1200, O) and urea (U). The base diets were composed of corn silage alone during the growth period and corn silage plus cracked corn during the finishing period. Trial 1 consisted of 40 animals [272 ± 4 kg body weight (BW)] individually fed the base diets and six treatments, which were based on corn silage alone and cracked corn supplemented with U or O to supply 50 (U50, O50) or 100% (U100, O100) of the ruminal N deficiency (U50, O50, U100, and O100) as predicted by the Cornell Net Carbohydrate and Protein System (CNCPS), or with U and O each supplying half of the CNCPS predicted N deficiency (U25O25). In trial 2, 120 pen-fed animals (241 ± 7 kg BW) received the base diets and four combinations of U and O ( U100O0, U66O34, U34O66, and U0O100), which were designed to supply 100% of the ruminal N deficiency predicted by the CNCPS. In trial 1, no differences (P > 0.05) in performance were observed between the U100 and O100 treatments, but animals in the U50 treatment had a greater average daily gain (ADG) (P < 0.05) and feed conversion (P < 0.05) than animals on O50 treatment. In trial 2, combinations of U and O did not affect animal performance (P > 0.05). No differences were observed in carcass characteristics and predicted carcass and empty body fat for both trials (P > 0.05). We concluded there was no improvement in animal performance when urea was substituted by a slow-release urea/NH3 product at levels normally found in feedlot cattle diets. Key words: Cornell net carbohydrate and protein system, modeling, nutrition, growth, non-protein nitrogen
Growth and fur characteristics of blue foxes (Alopex lagopus) fed diets with different protein levels and with or without DL-methionine supplementation in the growing-furring period
Authors: Dahlman T. , Valaja J. , Jalava T. , Skrede A.
Published: April 2011

A production trial was carried out on 125 growing-furring blue foxes (Alopex lagopus) to study the effects of low-protein diets, with or without DL-methionine supplementation, on growth performance and fur characteristics. The treatment codes were P30, P22.5, P22.5M, P15, and P15M. The protein contents [g kg-1 DM (dry matter)] of the diets were 300, 243, 243, 174, and 177, respectively. DL-methionine was added to P22.5M and P15M to yield a total dietary content of methionine (M) corresponding to that in P30. From August to mid-September, the weight gain of the blue foxes receiving the diet with the lowest protein level and the lowest methionine content (P15) was significantly lower than that of the blue foxes in treatments P22.5 and P30. In contrast, growth of the blue foxes in P15M did not differ from that of the blue foxes in P22.5 or P22.5M. From mid-September to pelting, weight gain did not differ significantly among treatments. Guard hair quality was significantly impaired in the low-protein diets without methionine supplementation, but not in those diets supplemented with methionine. Methionine appeared to be the first limiting amino acid for winter fur development. Addition of DL-methionine and use of low-protein diets for blue foxes would be beneficial in terms of reduced feed expenses and lower nitrogen emissions to the environment. Key words: DL-methionine, protein, amino acids, growth, fur skin quality, blue fox (Alopex lagopus)
Dietary urea, exogenous estradiol-17β, and nitrogen utilization in Holstein steers fed a low-protein diet
Authors: Knaus W. F. , Beermann D. H. , Tedeschi L. O. , Guiroy P. J. , Boehm M. L. , Fox D. G.
Published: April 2011

The Cornell Net Carbohydrate and Protein System model was used to formulate a low-protein mixed grass hay and corn diet predicted to create a ruminal N deficiency of 33% in 250-kg Holstein steers. Nitrogen metabolism, digestibility and metabolic status responses were compared between this control diet and a similar diet supplemented with 1.7% urea to compensate for the ruminal N deficiency. A 4 × 4 Latin square design was used to analyze main effects of diet and subcutaneous administration of 500 μg estradiol-17β (E2) twice a day. Urea supplementation increased N intake from 60 to 93 g d-1, improved N balance from 10.1 to 17.7 g d-1, and improved total tract digestibility of N, neutral detergent fiber (NDF), organic matter (OM), and dry matter (DM) (all P < 0.05), but there was no effect of urea supplementation on total tract digestibility of non-structural carbohydrate (NSC) and N retention (percent of N intake). Plasma urea N increased fourfold (P < 0.05) and plasma insulin increased from 0.32 to 0.50 ng mL-1 (P = 0.06) when the urea diet was fed. Administration of E2 did not alter N metabolism or plasma metabolites and insulin at either level of protein intake. It is concluded that supplementing a fiber-rich grass-hay-based diet with urea to achieve ruminal N balance increases digestibility of fiber fractions without altering dietary N utilization. Under these nutritional conditions the use of estrogenic growth promoters remains ineffective independent of ruminal N balance. Key words: Steers, nutrition, fiber, urea, estradiol, nitrogen balance
Acidification of urine by feeding anionic products to non-lactating dairy cows
Authors: Bowman G. R. , Beauchemin K. A. , Rode L. M.
Published: April 2011

Three commercial anionic products (Bio-Chlor MM™, Bio-Chlor FR™ and SoyChlor 16-7™) were fed to non-lactating dairy cows in a total mixed ration (TMR). After the anionic products were included in the TMR at the manufacturers’ recommendations for 4-d, all products reduced urine pH below the desired threshold of 6.5. The rate at which the products reached nadir urine pH differed among the products, but once acidification was accomplished temporal effects on pH were minimal. Key words: Urine pH, dietary cation-anion difference, prepartum, dairy cow, non-lactating
Interaction of amino acids and insulin in the regulation of protein metabolism in growing animals
Authors: Davis T. A. , Suryawan A. , Bush J. A. , O’Connor P. M. J. , Thivierge M. C.
Published: April 2011

Young animals utilize their dietary amino acids more efficiently for growth because they are capable of a greater increase in tissue protein synthesis in response to feeding than older animals. This response to feeding is particularly profound in skeletal muscle. The feeding-induced stimulation of protein synthesis in skeletal muscle is uniquely and independently regulated by both insulin and amino acids. In most visceral tissues, the stimulation of protein synthesis by feeding is mediated by amino acids alone and not by insulin. The stimulation of protein synthesis by nutrition and hormones is regulated by alterations in the expression and activity of components of the intracellular signaling pathways that control the initiation of translation. Key words: Muscle, pigs, neonate, protein synthesis, insulin, amino acids
Defining the tolerable level of ergot in the diet of weaned pigs
Authors: Oresanya T. F. , Patience J. F. , Zijlstra R. T. , Beaulieu A. D. , Middleton D. M. , Blakley B. R. , Gillis D. A.
Published: April 2011

The present study investigated the effect of ergot alkaloids on performance and clinical symptoms in weaned pigs. Wheat ergot sclerotia (1880 mg alkaloid kg-1; ergocristine, ergotamine, ergosine, ergocryptine, and ergocornine constituting 40, 36, 11, 7, and 6% of the total, respectively) were added on a weight basis to a basal diet at 0.00 (control), 0.05, 0.10, 0.25, 0.50, and 1.00% and fed to 192 weaned pigs (20.4 ± 3.4 d; 6.9 ± 1.3 kg; mean ± SD) for 28 d, beginning 7 d post-weaning. Pigs fed the 1.00% diet gained 82 and 38% less than the control (P < 0.001, 211 vs. 39 g d-1, wk 1 and 432 vs. 269 g d-1, wk 2) and body weight on day 28 was reduced quadratically by alkaloids (P < 0.005). Ergot alkaloids decreased average daily feed intake (ADFI) quadratically (P < 0.04) and feed efficiency linearly (P < 0.03) (0.62 vs. 0.44; control vs. 1.00%) over the entire period, but ADFI was not affected during the initial 14 d (P > 0.20). Ergot alkaloids decreased serum prolactin quadratically (P < 0.002) and urea nitrogen concentrations (P < 0.05). The maximum tolerable ergot level in the diet was 0.10 and 0.05% based on average daily gain (ADG) and ADFI, respectively, corresponding to 2.07 mg and 1.04 mg alkaloid kg-1 diet. Key words: Pig, ergot, alkaloid, toxicity, performance, prolactin
Evaluation of the National Research Council (NRC) nutrient requirements for beef cattle: Predicting feedlot performance
Authors: Okine E. K. , McCartney D. H. , Basarab J. B.
Published: April 2011

The accuracy of predicted CowBytes® versus actual dry matter intake (DMI) and average daily gain (ADG) of 407 Hereford × Angus and Charolais × Maine Anjou (445.6 ± 36 kg) feeder cattle using digestable enery acid detergent fiber (DE) estimated from the (ADF) content [Laboratory analysis method (LAB)] and from values determined in vivo (INVIVO method) was examined. The diet consisted of a 73.3% concentrate diet, 22.0% barley silage, 1.6% molasses, and 3.1% feedlot supplement fed ad libitum (as-fed basis). The calculated DE values of the feed were used to predict the metabolizable energy (ME), net energy of maintenance (NEm), and net energy of gain (NEg) of the diet. These energy values were then used in CowBytes® to predict dry matter intake (DMI), ADG, and days on feed (DOF) necessary to meet targeted quality grade of AA and weights of 522 and 568 kg for the heifers and steers, respectively. There was no effect of gender and prediction method interaction (P > 0.10) on any of the variables measured. There were no (P > 0.05) differences in predicted DMI by either the INVIVO or LAB method but both methods underestimated DMI actually consumed by the cattle by 6.8 and 4.9% (P = 0.007), respectively. Indeed, regression values from these predictive methods and actual DMI were (P < 0.05) different from the one-to-one relationship expected by definition. In spite of the higher actual DMI, the actual ADG of the cattle was 14 and 11% (P = 0.0004) lower than was predicted by either the INVIVO or LAB methods. A possible reason for the lower ADG could be an overestimation of DE of the diet. Thus, if available, users of CowBytes® should use actual DMI from their experience in ration formulation. In addition, the effects of environmental temperature on digestibility of diets should be taken into consideration when using the DE of the diet as determined from in vivo digestibility trials or calculated from chemical analyses in determining the DMI of feedlot cattle. Key words: Beef cattle, performance, CowBytes®, National Research Council
Amino acid requirements in inflammatory states
Authors: Obled C.
Published: April 2011

The metabolic disturbances that accompany an inflammatory challenge redirect nutrients from physiological processes important for growth and reproduction toward processes important in host defense. These processes can require increased provision of particular amino acids from the diet in order to spare body protein stores. The pathways that are activated in response to inflammation have to be determined in order to quantify their specific amino acid requirements. For example, increased synthesis of acute phase proteins would require additional supply of specific amino acids according to their amino acid composition. Some dispensable amino acids can become limiting because their de novo synthesis could be impaired and/or be insufficient to cover the increased demands for synthesis of important metabolites. Moreover, amino acids can act on gene expression and as mediators or signal molecules and modulate numerous functions. However, the optimal conditions, especially concentration in physiological liquids, all owing the best expression of these activities are not yet well defined. Key words: Amino acids, requirements, inflammation, protein, metabolism, glutathione, glutamine
Estimation of faecal output, digestibility, and intake using a controlled release capsule of alkanes in early and late lactation dairy cows fed two levels of concentrate
Authors: Ouellet D. R. , Petit H. V. , Veira D. M. , Charmley E.
Published: April 2011

Thirty-two dairy cows (663 ± 70; kg of BW ± SD) were allotted to a 2 × 2 factorial arrangement of treatments to evaluate the controlled release alkane capsule (CRC; C32 and C36) to estimate digestibility and dry matter (DM) intake in early and late lactation for diets based on low (LC, 30%) or high (HC, 60%) proportions of concentrate. Cows were dosed orally with a CRC into the rumen and digestibility was measured by total collection and estimated from the ratios of alkanes in the diet and faeces. Recoveries of endogenous (C31 and C33) and exogenous (C32 and C36) alkanes were higher and lower, respectively, for LC compared with HC. The effects of diet and the interaction between diet and lactation stage were well estimated (P < 0.05) when measured released rates of C32 and C36 were used to estimate DM digestibility although estimation with both alkanes indicated an effect of lactation stage, which was not observed when using data of measured DM digestibility. The faecal ratio of C31/C32 or C33/C32 showed no diet effect on DM intake estimation while measured DM intake was 22.6% higher for cows fed HC than for those fed LC. In conclusion, estimation of DM intake was inadequate although digestibility of DM was estimated from alkanes contained in the CRC. Key words: Dairy cows, alkane, intake
In vitro assessment of corpus luteum function in cattle following Ovsynch and CIDR ovulation synchronization protocols
Authors: Aali M. , Small J. A. , Giritharan G. , Ramakrishnappa N. , Cheng K. M. , Rajamahendran R.
Published: April 2011

Non-lactating beef cows (N = 40) were used to determine in vitro production of progesterone by CLs collected on days 6–8, 13–15 and 19–20, following Ovsynch or CIDR ovulation synchronization protocols. Progesterone released by the CL tissues into the medium was measured after 1 h of incubation (control) and after 6 h of hormone treatments (LH, PGF2α or LH + PGF2α). In vitro progesterone production did not differ (P > 0.05) between Ovsynch and CIDR ovulation synchronization protocols. Pooled data, irrespective of ovulation synchronization treatments, showed interaction (P < 0.05) between hormone treatment and stage of CL. Key words: Corpus luteum, progesterone, cows, ovulation synchronization
Current and residual effects of nitrogen fertilizer applied to grass pasture on production of beef cattle in central Saskatchewan
Authors: Cohen R. D. H. , Wright S. B. M. , Thomas L. R. , McCaughey W. P. , Howard M. D.
Published: April 2011

Four rates of nitrogen fertilizer (0, 50, 100 and 200 kg N ha-1) were applied for 4 yr to two replications of a 32-yr-old crested wheatgrass (Agropyron cristatum) pasture at Lanigan, Saskatchewan, after which no fertilizer was applied for a further 4 yr. The pastures were grazed by pregnant yearling Hereford heifers using a “put-and-take” stocking system. Soil cores (0–60 cm) were taken to monitor soil NO3-N concentrations either in early spring, before grass growth commenced, or in late fall, after grass growth had ceased. Pasture measurements included available forage at the start of the grazing season, total forage production and the concentrations of crude protein, acid detergent fiber (ADF), ash, Ca, P, Mg, K, Cu, Zn, Fe and Mn. Heifers, fistulated at the esophagus, were used in 1984 and 1985 to obtain samples of the grazed herbage, which were analyzed for organic matter digestibility (OMD), protein and minerals, except P and K. Heifer intakes of digestible organic matter (DOMI), protein and minerals, except P and K, were estimated from their concentrations in fistula extrusa and estimates of intake obtained from extrusa digestibility and fecal output using Cr2O3 as a fecal marker. Phosphorus intake was estimated from fecal P concentration. Plasma samples were also collected and analyzed for concentrations of minerals.
A within-animal examination of postmortem ageing for up to 21 d on tenderness in the bovine longissimus thoracis and semimembranosus muscles
Authors: Aalhus J. L. , Dugan M. E. R. , Robertson W. M. , Best D. R. , Larsen I. L.
Published: April 2011

The present research shows an interesting example of ageing up to 21 d having a differential effect on tenderness in the longissimus thoracis (LT) and semimembranosus (SM) muscles. When compared to 1 d postmortem, Warner - Bratzler shear (WBS) progressively decreased over time postmortem in the LT (12.05 kg at 1 d vs. 8.08 kg at 6 d, 6.95 kg at 14 d, and 5.52 kg at 21 d) but not in the SM (9.81 kg at 1 d vs. 8.19 kg at 6d, 8.43 kg at 14 d, and 9.30 kg at 21 d). Introduction of muscle-specific ageing times in industry could reduce tenderness variation and reduce refrigeration costs. Key words: Beef, ageing, tenderness, longissimus thoracis, semimembranosus
Factors affecting intestinal starch digestion in ruminants: A review
Authors: Harmon D. L. , Yamka R. M. , Elam N. A.
Published: April 2011

The process of starch assimilation in the ruminant is complex and remains an avenue by which increases in production efficiency can be gained. Ruminal starch digestion is typically 0.75–0.80 of starch intake. Starch that escapes fermentation and flows to the small intestine may be more resistant to enzymatic digestion and on average 0.35–0.60 of starch entering the small intestine is degraded there. Of the fraction that escapes small intestinal digestion an additional 0.35–0.50 is degraded in the large intestine. This suggests that limitations to small intestinal starch digestion do exist. This review summarizes available information describing the digestive and absorptive processes occurring in the small intestine with an emphasis on nutritional factors that influence these processes. A review of experiments measuring small intestinal starch digestion indicates that small intestinal digestion is either highly variable or poorly determined whereas ruminal and large intestinal digestion are much more clearly described. These data indicate that improvements in methodologies are needed before we can accurately describe processes occurring in the small intestine and formulate diets to optimize site of starch digestion. Key words: Ruminant, starch, glucose, small intestine, digestion
Frankfurters — acceptability under different retail lights
Authors: Barbut S.
Published: April 2011

Dark, medium, and light colour frankfurters (no-fat, low-fat, and regular fat level) were evaluated by panellists under incandescent (INC), fluorescent (FL), and metal halide (MH) light sources. INC illumination resulted in a higher colour preference (P < 0.05) for the medium and light products over that of the FL and MH illuminations; no significant difference was seen between FL and MH lighting. The panellists described the medium coloured frankfurters as pink under INC lighting, but more brown under FL and MH illumination. Relative luminance data, collected via a fibre optic probe connected to a photo diode array, demonstrated the reason to be the low red colour seen by the panellists under FL and MH light sources. For the dark colour frankfurters, there was no difference in colour preference scores among the three illumination sources. Key words: Colour, fat, frankfurters, light, meat, sausage, sensory, spectra
Using X-ray absorption near edge structure (XANES) spectroscopy to determine selenium oxidation states in animal mineral supplements and feeds
Authors: Christensen C. R. , Cutler J. N. , Christensen D. A.
Published: April 2011

Synchrotron-based X-ray absorption near edge structure (XANES) spectroscopy is a relatively new technique within the life sciences. XANES has been utilized to identify the location, oxidation state and spatial distribution of heavy metal elements in plants , neurons, blood and DNA, but has not been widely used in the animal sciences. Selenium content in animal feeds is monitored, as both selenium deficiencies and toxicities are associated with physiological disorders. Selenium is available as an animal feed in both inorganic and organic states. The bioavailability of selenium species has been tested in numerous animal trials; however, a simple, non-destructive test for selenium speciation is not available. The objective of this study was to determine whether XANES spectroscopy could be used to determine the selenium oxidation state found in various commercial animal feed products. A comparison of absorption spectra indicated that the animal mineral supplements contained an organoselenium or selenite. The processed animal feeds had a spectral profile similar to that of elemental selenium. Further experiments are necessary to determine the implication of selenium speciation on animal physiology. Key words: Selenium speciation, mineral supplements, ruminants, non-ruminants, synchrotron, XANES, X-ray
The use of MIXED models in the analysis of animal experiments with repeated measures data
Authors: Wang and L. A. Goonewardene Z.
Published: April 2011

The analysis of data containing repeated observations measured on animals (experimental unit) allocated to different treatments over time is a common design in animal science. Conventionally, repeated measures data were either analyzed as a univariate (split-plot in time) or a multivariate ANOVA (analysis of contrasts), both being handled by the General Linear Model procedure of SAS. In recent times, the mixed model has become more appealing for analyzing repeated data. The objective of this paper is to provide a background understanding of mixed model methodology in a repeated measures analysis and to use balanced steer data from a growth study to illustrate the use of PROC MIXED in the SAS system using five covariance structures. The split-plot in time approach assumes a constant variance and equal correlations (covariance) between repeated measures or compound symmetry, regardless of their proximity in time, and often these assumptions are not true. Recognizing this limitation, the analysis of contrasts was proposed. If there are missing measurements, or some of the data are measured at different times, such data were excluded resulting in inadequate data for a meaningful analysis. The mixed model uses the generalized least squares method, which is generally better than the ordinary least squares used by GLM, if the appropriate covariance structure is adopted. The presence of unequally spaced and/or missing data does not pose a problem for the mixed model. In the example analyzed, the first order ante dependence [ANTE(1)] covariance model had the lowest value for the Akaike and Schwarz’s Bayesian information criteria fit statistics and is therefore the model that provided the best fit to our data. Hence, F values, least square estimates and standard errors based on the ANTE (1) were considered the most appropriate from among the five models demonstrated. It is recommended that the mixed model be used for the analysis of repeated measures designs in animal studies. Key words: Repeated measures, General Linear Model, Mixed Model, split-plot, covariance structure
Use of recorded nursing grunts during lactation in two breeds of sows. II. Effects on sow performance and mammary development
Authors: Farmer C. , Fisette K. , Robert S. , Quesnel H. , Laforest J. P.
Published: April 2011

Primiparous lactating sows of two different genotypes [42 Genex-Meishan hybrid (MH) and 42 Yorkshire-Landrace (YL)] were exposed to recorded nursing grunts played at different intervals, and the effects on sow performance and mammary growth were studied. Sows within each breed were divided in three groups (n = 14 for each group): (1) no playbacks (control), (2) playbacks at 35-min interv als (GR35), and (3) playbacks at 40-min intervals (GR40). Recordings were played from day 110 of gestation to day 28 of lactation. Litter size was standardized to 10 ± 1 pigs within 48 h postpartum, and weight and backfat thickness of sows were recorded on day 110 of gestation, and on days 2 and 27 of lactation. Sow feed and water intakes were recorded throughout lactation. Milk samples were obtained from all sows on day 27 postpartum and jugular blood samples were obtained on day 28 for measurement of IGF -I and prolactin concentrations. Sows were slaughtered on day 28 of lactation and their mammary glands were excised to perform compositional analyses. Ovaries were also collected. The MH sows weighed less (P < 0.01) and had more backfat (P < 0.01) than YL sows. Milk from MH sows contained more dry matter (P < 0.05) and more lactose (P < 0.05) than that from YL sows. Mammary parenchymal tissue weighed less (P < 0.05) and contained less total protein (P = 0.01) and total DNA (P < 0.01) in MH than in YL sows. Sows in GR35 also had more total parenchymal DNA (P < 0.05) than control sows. Circulating concentrations of IGF-I and prolactin were not affected by breed or treatment (P > 0.1) whereas ovaries were heavier (P < 0.01) in control MH than in control YL ows. Therefore, playbacks of nursing grunts at 35-min intervals throughout lactation increased total mammary cell number without affecting hormonal or milk composition status. Key words: Auditory stimulus, lactation, mammary development, Meishan, milk, sows
Effect of dietary fenugreek seed on dairy cow performance and milk characteristics
Authors: Shah M. A. , Mir P. S.
Published: April 2011

The effect of providing fenugreek seed at 20% of diet dry matter on dairy cow performance and milk characteristics was studied. Feeding fenugreek seed improved profile of functional fatty acids (P < 0.05) in the milk, reduced blood cholesterol concentration (by 4% units more than the control diet) and produced lower concentrations in milk (1.48 vs. 1.83 mg g-1 milk lipid) in a 3-wk study with dairy cows, without altering milk flavour or taste. Therefore, fenugreek seed could be used in dairy rations to improve milk characteristics. Key words: Fenugreek, cholesterol, dairy cows and fatty acids
Assessment of the effects of the season of transport on the performance of early-weaned piglets
Authors: Lewis N. J. , Berry R. J. , Crow G. , Wamnes S.
Published: April 2011

Six groups of 48 Cotswold piglets, weaned at 17 ± 1 d of age, were transported during three seasons (summer, winter or fall) and for four durations (0, 6, 12 or 24 h). As in commercial transport, feed and water were not available and supplemental heat was not provided. During transport, truck temperatures and piglet skin and rectal temperatures were recorded. At the end of transport piglets were placed in groups of four, in weanling pens. Body weights were recorded daily for 7 d and at 14 d.
Utilization of fortified cubes to deliver trace minerals and monensin in forage-based diets
Authors: Ominski K. H. , Boadi D. A. , Wittenberg K. M.
Published: April 2011

The potential benefits of mineral or monensin delivery through forage cubes vs. free-choice were investigated in Simmental × Charolais pregnant cows and their calves. Thirty-six mid-gestation cows (615 ± 21 kg) placed in 18 pens were initially depleted of liver Cu reserves by feeding a TMR containing 100 mg Mo kg-1 DM and 4 g S kg-1 DM for 42 d, allowed to stabilize on a low Mo, Cu and S diet for 42 d and were then used in a mineral uptake study. Experimental diets containing chopped grass-hay were fed ad libitum with one of the following three alfalfa-barley grain cubes at 2 kg head-1 d-1: (1) no addition of mineral and ionophore (Free Choice); (2) addition of mineral and no ionophore (+M Cube); and (3) addition of mineral and ionophore in the form of monensin (+M+I Cube). Mineral intake and mineral status (through liver biopsy and blood sampling) were monitored over a 16-wk feeding period, which included the first 6 wk post-calving. Dry matter intake by Free Choice cows prior to calving was higher than that by +M Cube and +M+I Cube fed cows (P < 0.05). Pre- and post-calving mineral intake (g pen-1 d -1) by Free Choice cows was 31.6% higher than +M Cube and +M+I Cube fed cows (P < 0.01). The coefficient of variation for day-to-day and pen-to-pen variation for cows consuming free choice mineral was 81 and 36%, respectively. There was no variation in supplemental mineral intake for +M Cube and +M+I Cube fed cows due to complete consumption of all forage cubes offered. Dietary treatment did not influence mean serum Cu and Zn concentration or plasma ceruloplasmin oxidase (Cp) activity of cows (P > 0.05). However, liver Cu concentration (mg kg-1) of +M+I Cube fed cows tended to be higher than for the other treatment groups (P = 0.06). Calf ADG at 6 wk of age was not affected by dietary treatment of dams (P > 0.05). Copper and Zn status of calves at 6 wk of age was not different among dam dietary treatments. However, plasma Cp activity declined more rapidly in +M+I Cube calves compared with +M Cube calves (P < 0.05), which may be attributed to the presence of monensin in the +M+I Cube diet of late gestation cows. Fortified cubes may be used as an effective means of eliminating the variability in mineral intake associated with free choice consumption with no detrimental effect on mineral status of cows and their suckling calves. Key words: Forage cubes, trace minerals, monensin, pregnant cows, calves
Factors affecting the apparent intestinal (small and large) disappearance of dry matter and crude protein from rumen undegradable residues of various feeds determined using the mobile bag technique for cattle
Authors: Loveday D. M. , Block H. C. , Thacker P. A. , McKinnon J. J.
Published: April 2011

This study evaluated the effects of retention time in the post-abomasal digestive tract, washing time (15, 50, 75, 100 s), bag size (3.5 × 5.5 vs. 2.5 × 4.0 cm), sample size to surface area ratio (3.9 vs. 7.5 mg cm-2), pepsin treatment (untreated vs. pepsin-HCl) and bag material (nylon vs. polyester) on apparent dry matter (DM) and crude protein (CP) disappearance from rumen undegradable residues (RUDR) of canola meal, soybean meal, barley straw, barley silage and dehydrated alfalfa using the mobile bag technique. RUDR were placed into 44 or 48 µm mesh size bags and inserted into the duodenum of cannulated steers, with bags recovered in feces. Retention time of bags was not influenced by substrate. Small bags took slightly longer (P < 0.05) to pass through the post-abomasal digestive tract. Retention time in the post-abomasal digestive tract did not affect CP disappearance but had a minor impact on DM disappearance (P < 0.05). Interactions (P < 0.05) were noted between bag size, washing time and substrate. Bag material (nylon vs. polyester) influenced (P < 0.05) CP but not DM disappearance. No effects of pepsin HCl pre-incubation or SS:SA ratio were observed. Polyester may be preferred due to the high N content of nylon. Key words: Cattle, mobile bag technique, nutrient disappearance
Effects of skeletal separation method and postmortem ageing on carcass traits and shear force in cull cow beef
Authors: Mandell I. B. , Campbell C. P. , Quinton V. M. , Wilton J. W.
Published: April 2011

Sixty-six cull cow carcasses were subjected to skeletal separation methods for improving beef tenderness as evaluated using shear force. Forty-one carcasses were used to evaluate the effect on longissimus muscle shear force from skeletal separation at various sites including: (1) the 11th thoracic vertebra, (2) the 12th thoracic vertebra, and (3) the 6th thoracic and 5th lumbar vertebrae. Longissimus muscle steaks from the posterior and anterior loin and posterior rib were aged for 2, 7, 14, and 28 d. Twenty-five carcasses underwent skeletal separation processing in the round with severing of the ischium and the junction between 4th/5th sacral vertebrae. Semimembranosus, semitendinosus, biceps femoris, vastus lateralis, and rectus femoris muscles were processed into steaks and aged for 2, 7, 14, and 28 d. Skeletal separation techniques involving thoracic and lumbar vertebrae decreased (P < 0.04) shear force in the posterior rib and anterior loin but not in the posterior loin. Shear force continued to decrease (P < 0.01) as postmortem ageing duration increased. The semimembranosus was the only muscle in the round in which shear force decreased (P < 0.01) with skeletal separation. Postmortem ageing for at least 14 d decreased (P < 0.06) shear force in semimembranosus and vastus lateralis steaks while there were no further decreases in shear force after 7 d ageing for semitendinosus and rectus femoris steaks. Skeletal separation increased (P < 0.10) sarcomere length in all muscles studied. Skeletal separation techniques have the potential to improve tenderness in the longissimus and semimembranosus muscles, which may increase utilization of cull cow beef. Key words: Beef, cow, shear, tendercut, longissimus, round
Enteric methane emissions from backgrounded cattle consuming all-forage diets
Authors: Ominski K. H. , Boadi D. A. , Wittenberg K. M.
Published: April 2011

To quantify enteric methane (CH4) emissions of growing cattle consuming allforage diets, a field study utilizing 144 British × Continental crossbred steers (262 ± 4 kg) was conducted during an 84-d overwintering period followed by a 56-d grazing period in one of two, grass-based pastures. Enteric CH4 emissions were quantified using the sulphur hexaflouride (SF6) tracer gas technique. During the overwintering period, four qualities of chopped alfalfa-grass silage, ranging in NDF content from 46.4 to 60.8%, DM basis, were utilized. Steers fed the lowest quality forage (60.8% NDF) had lower DMI, (6.8 ± 0.4 kg head-1, P = 0.0075) and lower ADG (0.83 ± 0.03 kg d-1, P = 0.0028) compared with those fed higher quality forage whose intake ranged from 8.2 to 9.1 ± 0.4 kg d-1, with gains ranging from 1.00 to 1.06 ± 0.03 kg d-1. Enteric emissions (% GE intake) were not influenced by forage quality across this range of NDF values; however, CH4 losses did decrease from 6.8 to 4.7 ± 0.3% GE intake as the winter period progressed. Increased DMI, accompanied by a decrease in the proportion of feed energy lost as enteric CH4 emissions, suggests that utilization of the lower-quality forage improved as steers reached higher body weights. Emissions were influenced by pasture quality and availability, as highest CH4 emissions (11.3% GE intake, P = 0.0005) were observed when quality was low and DM availability was limited (738 kg ha-1). This study demonstrates that growing cattle consuming all-forage diets typical of those utilized in Western Canada during the winter feeding period will lose 5.1 to 5.9% of feed energy as CH4. Further, it has shown that emissions from growing cattle on grass-based pastures may exceed 10% GE intake – a value that is greater than those previously reported for growing cattle grazing legume-based pastures. Key words: Enteric methane emissions, cattle, forage, backgrounding, pasture
Trends in growth and age at first calving for Holstein and Ayrshire heifers in Quebec
Authors: Pietersma D. , Lacroix R. , Lefebvre D. , Cue R. , Wade K. M.
Published: April 2011

The objective was to provide an overview of heifer growth in Quebec and analyze its relationship with age at first calving. Heifer body weights, wither heights, body condition scores, and breeding events collected from 1993 to 2003 were obtained and combined with first lactation data, mature body weights, type classification final score and frame/capacity, and estimated breeding values for milk, conformation, frame/capacity, and Lifetime Profit Index. Analyses were restricted to 39 animal-level variables. The resulting data set consisted of 44 989 Holsteins and 2294 Ayrshires with data available for at least one variable. The average age at first calving was 26.5 and 27.1 mo for Holsteins and Ayrshires, respectively. For Holsteins, average daily gains in body weights were 0.79, 0.89, 0.87, and 0.70 kg d-1 for 0 to 4 mo (birth to weaning), 4 to 10 mo (to target onset of puberty), 10 to 14 mo (to first breeding), and 14 mo to pre-calving periods of growth, respectively. Body weights at 14 mo, conception, and post calving were 398, 464, and 601 kg, respectively, and relative to mature body weight were 59, 68 and 89%, respectively. Correlations with age at first calving, corrected for herd and year of birth effects, were positive for body weight at conception (0.69), body weight at first calving (0.31), and number of breedings (0.37), and negative for the average daily gain from conception to post calving (-0.38) and body weight at 14 mo relative to mature body weight (-0.20). For Ayrshires, body weights and average daily gains were lower than for Holsteins, but body weights relative to mature body weight and correlations were generally similar. Holsteins and Ayrshires calved substantially earlier and at a heavier body weight compared with Quebec data from the 1980s. The results of this study suggest that heifer growth may not be a limiting factor in reducing the average age at first calving in Québec. Key words: Dairy cattle, field-recorded data, heifer, growth
Use of sodium bicarbonate, offered free choice or blended into the ration, to reduce the risk of ruminal acidosis in cattle
Authors: Paton Laura J , Beauchemin Karen A , Veira Douglas M , von Keyserlingk Marina A. G.
Published: April 2011

A study was conducted to determine whether feeding sodium bicarbonate (SB) reduces the risk of subacute ruminal acidosis in cattle fed high concentrate feedlot finishing diets. The experiment was conducted as a replicated 3 × 3 Latin square design with two squares and 2-wk periods. Three mature, non-lactating Holstein cows were allocated to square 1 and three mature Jersey steers were allocated to square 2. The cattle were ruminally cannulated and gradually adapted to a high concentrate diet before starting the experiment. The basal diet contained approximately 80% stream-rolled barley, on a dry matter (DM) basis, and was offered for ad libitum intake. Treatments were: control (no SB), control diet with cattle given free choice access to a SB mixture consisting of 70% SB and 30% dried molasses (free choice SB), and control diet supplemented with SB (7 g SB kg-1 DM; mixed SB). Ruminal pH was measured at the end of each 14-d period for 3 continuous days using an indwelling pH system. Dry matter intake (DMI) was not affected by treatment. However, SB intake depended upon type of cattle and method of provision (P = 0.04); cows had higher SB intake when it was mixed into the diet (57.8 vs. 17.4 g d-1), whereas steers had higher SB intake when SB was provided free choice (129.1 vs. 56.1 g d-1). Ruminal pH characteristics (mean, maximum, minimum, hours, and area under a threshold pH of 5.8 or 5.5) were not affected by treatment. Although neither method of delivering SB reduced the total time each day that pH was below the pH thresholds used to indicate subacute ruminal acidosis, the number of long (> 4 h) continuous bouts of acidosis (pH ≤ 5.8) was reduced (P = 0.01) when SB was mixed into the ration compared with the control. When offered free choice, intake of SB was highly variable among animals and from day-to-day and was inversely correlated to DMI. However, there was no correlation between SB intake and ruminal pH indicating that, when given the opportunity, cattle did not select SB to help prevent ruminal acidosis. Providing SB, either free choice or mixed into the ration, did not eliminate subacute ruminal acidosis in cattle fed high-grain diets. However, mixing SB into the ration reduced the number of long bouts of ruminal acidosis, which could potentially reduce the negative consequences of ruminal acidosis on feed digestion. Key words: Acidosis, beef cattle, high-grain diets, ruminal pH, sodium bicarbonate
Effects of stall width and sow size on behaviour of gestating sows
Authors: Li Y. Z. , Gonyou H. W.
Published: April 2011

The adequacy of gestation stalls to accommodate the postural behaviour of sows is an important welfare concern. The behaviour of 184 sows from parity 0 to 9 was studied in stalls of four widths (55, 60, 65, and 70 cm). Postures, frequency of posture changes, contact with the stall and udder extension beyond the stall were observed for 24 h at 4 and 14 wk of gestation. Injuries were assessed based on number and severity at four 5-wk intervals. Sows spent less time standing and more time sitting in the narrower compared with wider stalls (P < 0.05). The proportion of lying time spent in lateral recumbancy was greater for larger than for smaller sows (P < 0.05) and larger sows made fewer postural changes (P < 0.05). The proportion of sows touching both sides of the stall, or with their udder extending into the adjacent stall, was affected by the interaction of stall width and sow size. Sows rarely touched both sides of the stall, nor did their udders extend into the adjacent stall, when the ratio of stall width (cm) to BW0.33 (kg) exceeded 10.7. Neither stall width nor sow size affected injury scores during the gestation cycle. Key words: Pigs, behaviour, gestating sow, gestation stall, width, body size