bluuebunny/crossref_metadata_2025 huggingface dataset:
Residual metabolizable energy intake and its association with diet and test duration
Authors: Goonewardene L. A. , Okine E. , Wang Z. , Spaner D. , Mir P. S. , Mir Z. , Marx T.
Published: April 2011

The objective was to determine if end-of-test residual metabolizable energy intake (RMEI) is correlated with RMEI values calculated earlier in the test on steers fed two forage (silage) or four forage-grain diets. As the days on test increased the variation in RMEI decreased in all diets. In all but the 85% alfalfa + 15% barley grain diet, test duration for RMEI may be reduced from 105 to 84 d. In the 100% alfalfa silage diet, it may be further reduced from 105 to 63 d (Spearman r = 0.90; Pearson r = 0.94; P < 0.01). The duration of testing required to obtain reliable estimates of RMEI may therefore also depend on the type of diet being fed. Key words: Residual metabolizable energy intake, crossbred steers, correlations, forage-grain diets, test duration
Genetic parameters and breed differences for feed efficiency, growth, and body composition traits of young beef bulls
Authors: Schenkel F. S. , Miller S. P. , Wilton J. W.
Published: April 2011

Genetic associations between feed efficiency, growth, and live ultrasound measured body composition traits were studied in purebred beef bulls of six breeds in Ontario bull test stations from 1991 to 2000. Feed traits included average daily feed intake (FI), feed conversion ratio (FCR), and residual feed intake [feed intake adjusted for production alone (RFIp) or production and backfat thickness (RFIb)]. Growth traits were average daily weight gain (ADG), mid-test metabolic weight (MW), hip height (HH), and scrotal circumference (SC). Body composition traits included ultrasound backfat thickness (BF), longissimus muscle area (LMA), and predicted percentage of intramuscular fat (IFAT). Bulls were measured every 28 d for weight and individual feed intake, and at the end of test for ultrasound body composition traits. Number of records per trait ranged from 2284 (FI) to 13 319 (ADG). Fixed effects of test group, breed and end of test age (within breed), and random effects of animal and herd of origin were modeled using REML bivariate analyses for all traits. Heritability estimates were moderate for all traits (0.30 to 0.55), except for IFAT (0.14). The genetic correlation between RFIp and RFIb was high (0.99) within breeds, but breeds ranked differently with respect to RFIp and RFIb. Genetic correlations of RFIb with ADG and backfat thickness were essentially zero, which indicate that selection on residual feed intake could be implemented to reduce feed intake and improve feed conversion without compromising growth or changing levels of subcutaneous fat. Key words: Central test, genetic correlation, heritability, residual feed intake
Development of in vitro tests to predict fertility of bulls
Authors: Giritharan G. , Ramakrishnappa N. , Balendran A. , Cheng K. M. , Rajamahendran R.
Published: April 2011

The overall objective was to develop an in vitro test to predict fertility of bulls in the field. We investigated the bull effect on in vitro embryo production, zona binding and acrosome reaction, and the correlation of this effect to field fertility meas ured by 60–90 d non-return rate. Frozen semen from three separate ejaculates of eight unrelated young bulls, obtained from an artificial insemination (AI) center, was used. On thawing, ejaculates from each bull were pooled, motile sperm were selected and (a) subjected to immunofluorescent assay at 0 and 4 h of incubation in capacitation medium to assess acrosome status, (b) used in an in vitro fertilization assay system to assess cleavage and blastocyst production rates, and (c) sperm-zona binding assay was carried out to determine the number of sperm bound to the zona pellucida of mature oocytes. Percentage of pre-freeze motile sperm (PrFM) and non-return rate data were obtained from the AI center. PrFM, percentage of acrosome reacted sperm at 0 h (AR1), increase in percentage of acrosome reacted sperm after 4 h (InAR) and sperm-zona binding rates (ZB) differed (P < 0.05) among sperm samples obtained from different young bulls. Significant correlations (P < 0.05) were observed between PrFM and AR1 (r = -0.31), InAR (r = 0.36), and ZB (r = 0.32). AR1 was negatively correlated to ZB (r = -0.27) and cleavage rate (r = -0.20), InAR was positively correlated with ZB (r = 0.31) and cleavage rate (r = 0.26). None of the in vitro tests was correlated with non-return rate. These findings indicate that along with pre-freeze motility, a combination of in vitro tests including the percentage of spontaneously acrosome reacted sperm at thawing, might be useful in predicting bull field fertility. Such a combination of assays, however, has yet to be determined. Key words: Field fertility, acrosome reaction, zona binding, IVF, fertility assay
Genetic association between cows’ stayability to three years of age and juvenile growth traits in Canadian Angus herds
Authors: Rasali D. P. , Crow G. H. , Shrestha J. N. B. , Kennedy A. D. , Brûlé-Babel A.
Published: April 2011

Bivariate linear animal models were fit using MTDFREML programs for the analysis of cows’ stayability to 3 yr (STAY3, n = 1, 703) as a binary scored trait paired with body weights at birth (BW, n = 6,116), 205-d weaning (WW, n = 5,360,) and 1 yr of age (YW, n = 5250) in Angus cattle. For STAY3, the model included a fixed effect due to herd ×year of cow’s birth along with a random direct genetic effect. For each of BW, WW and YW, the model included fixed effects due to herd ×birth year, birth season, birth type, calf’s sex and the age of dam (as linear and quadratic covariates), while the random effects were direct and maternal genetic effects and permanent maternal environmental effects. Survival analysis revealed that the risk of cows, 10 yr or less in age, being culled from five Canadian Angus herds was highest between 2 and 3 yr of age. The direct heritability (h2) estimates for BW, WW and YW were 0.54, 0.73 and 0.47, respectively, and corresponding maternal heritability estimates were 0.14, 0.33 and 0.13, respectively. Furthermore, the direct h2 estimate for STAY3 from three bivariate analyses was 0.23–0.24. Estimates of direct-maternal genetic correlations of BW, WW and YW were -0.18, -0.70 and -0.39, respectively. The direct genetic correlations of STAY3 with BW, WW and YW were -0.15 to -0.09 indicating that selection for growth would have less detrimental influence on the stayability trait of cows. The correlations of direct genetic effects of STAY3 with maternal genetic effects of BW, WW and YW were between 0.20 and 0.25, indicating their favorable relationships as correlated traits. Key words: Stayability, growth traits, heritability, genetic correlations, beef cattle
Use of live ultrasound, weight and linear measurements to predict carcass composition of young beef bulls
Authors: Bergen R. , Miller S. P. , Mandell I. B. , Robertson W. M.
Published: April 2011

Pre-slaughter ultrasound and whole side dissection data from 47 crossbred bulls were used to assess (1) the relative value of six previously published equations based on live animal measurements, (2) the value of alternative pre-slaughter measurements, and (3) the value of alternative ultrasound probes as predictors of whole side lean meat yield. Analysis of absolute bias-corrected residuals indicated that all six previously published equations predicted whole side lean meat yield with similar accuracy (P = 0.62), but analysis of absolute rank residuals indicated that an equation originally based on carcass measurements tended (P = 0.17) to rank bulls less precisely than five ultrasound-based equations. Breed composition, age, liveweight, hip width, heart girth, and round muscle depths did not contribute to new lean meat yield prediction equations (P > 0.10), but height, 12th/13th rib body wall, rump fat, and gluteus medius muscle depths and marbling score did (P < 0.10). However, examination of absolute residuals and absolute rank residuals indicated that accuracy (P = 0.55) and precision (P = 0.64) did not improve significantly compared to equations based only on height, rib fat and longissimus muscle size. Similarly, analysis of absolute residuals and absolute rank residuals indicated that fat and longissimus muscle depth measurements collected with a short probe predicted whole side lean meat yield as accurately and precisely as measurements collected with a long probe. Results indicated that (1) equations based on live measurements may provide more precise predictions of lean meat yield than equations derived from carcass measurements, (2) supplementing ultrasonic rib fat and longissimus muscle measurements with additional ultrasound measurements did not improve the accuracy or precision of lean meat yield prediction, and (3) lean meat yield of yearling bulls can be accurately predicted using fat and longissimus muscle depth measurements collected with a short probe. Key words: Ultrasound, beef bulls, carcass composition, prediction models
Physiological and behavioural changes in Holstein calves during and after dehorning or castration
Authors: Schwartzkopf-Genswein K. S. , Booth-McLean M. E. , McAllister T. A. , Mears G. J.
Published: April 2011

Physiological and behavioural responses of 17 bull and 12 heifer dairy calves (80.9 ± 1.4 kg) to either hot-iron dehorning or dehorning followed by scalpel castration were compared to both control and sham procedures and to each other. Blood samples were collected via jugular catheters at 15 and 30 min, 1, 2, 4, 24, and 48 h post procedure, sham or control. Cortisol levels remained elevated above controls for at least 2 h after castration and 30 min after dehorning. Initial (T0–T15 min) cortisol responses to castration were not different from those to dehorning. However, they were greater than for dehorning at 2 and 4 h post procedure. Both castrated and dehorned calves kicked and vocalized more frequently (P < 0.05) than during sham procedures. Struggling was greater during dehorning than the sham, but occurred less (P < 0.05) during castration than the sham possibly due to the prior experience of dehorning. Dehorned calves had a higher (P < 0.05) occurrence of both struggling and kicking compared to castrated calves. Heart rate was higher (P < 0.001), compared to control values, in both the sham (P < 0.02) and dehorned calves. Non-anaesthetized dairy calves had elevated cortisol, and heart rate levels as well as more severe behavioural responses to castration and dehorning compared to sham and control treatments. Differences in the responses to each procedure may have been due to handling differences or prior experience of dehorning. Key words: Behaviour, castration, cortisol, dairy calves, dehorning, heart rate
Comparisons of methods for in vitro dry matter digestibility of ruminant feeds
Authors: Brons E. , Plaizier J. C.
Published: April 2011

Apparent in vitro dry matter digestibilities of selected ruminant feeds were determined with the DAISYII incubator (ADD, ANKOM Technology Corp., Macedon, NY) and the Tilley and Terry technique (ADTT). True in vitro dry matter digestibility was also determined with the DAISYII incubator (TDD). The ADD and ADTT did not differ for grain crop silages and total mixed rations. The ADD was 9.0 percentage points higher than ADTT for grains and 3.4 percentage points lower than ADTT for grass and legume forages. The TDD was between 5.7 and 11.2 percentage points higher than ADD depending on the feed. Key words: In vitro dry matter digestibility, forages, grains, ANKOM DAISYII incubator
Lactation response of cows to different levels of ruminally inert conjugated linoleic acids under commercial conditions
Authors: Gervais Rachel , Spratt Richard , Léonard Martin , Chouinard P. Yvan
Published: April 2011

Dietary conjugated linoleic acid (CLA) supplements have been shown to reduce milk fat synthesis in dairy cows. A rumen-inert source of CLA is required for commercial feed applications. The conversion of dietary lipids to a calcium salt is considered as a method to counter the extensive hydrogenation of dietary lipids that occurs in the rumen. Our objective was to determine whether feeding calcium salts of CLA under commercial conditions would affect milk production, milk composition and blood metabolic profile. A total of 240 dairy cows from eight farms were blocked according to the calving date, and randomly assigned to four treatments providing CLA at 0, 8, 16 and 32 g d-1. Milk production was recorded and milk was sampled on day 0, 7, 14, 28 and 42 of the feeding period. Blood samples were taken on day 42 from early-lactating cows (< 157 d in milk) to determine the metabolic profile. Milk fat yield was decreased 11, 20 and 28%, and milk fat concentration was reduced 13, 22 and 28% (linear; P < 0.001) when cows received 8, 16 and 32 g d-1 of CLA, respectively. Milk yield, milk protein and blood metabolic parameters were not affected by experimental treatments. Calcium salts of CLA can be used as an effective tool to manage milk fat content on commercial dairy farms. Key words: Conjugated linoleic acid, milk fat, ruminally inert fat
Effect of full-fat hemp seed on performance and tissue fatty acids of feedlot cattle
Authors: Gibb D. J. , Shah M. A. , Mir P. S. , McAllister T. A.
Published: April 2011

Sixty individually penned steers (380 ± 39 kg) were fed barley-based finishing diets containing 0 (control), 9 or 14% full-fat hemp seed (HS) and effects on performance and tissue fatty acid profiles were assessed. At harvest, samples of pars costalis diaphragmatis (PCD) and brisket fat were collected from each carcass. Feeding HS did not affect (P > 0.25) dry matter intake (DMI), average daily gain (ADG), or gain feed-1. Carcass traits were also unaffected (P > 0.35) by treatment. Feeding HS linearly increased (P < 0.001) proportions of C18:0, C18:3 and C18:1 trans-9 in PCD, and 18:2 trans, trans in both PCD and brisket fat. As well, HS linearly increased cis-9 trans-11 CLA (P < 0.001), total saturates (P = 0.002) and polyunsaturated fatty acids (PUFA) (P = 0.01) in PCD. The presence of C20:4, C20:5 and C22:5 was detected only in tissues of cattle supplemented with HS (P < 0.06). Linear reductions (P < 0.002) in C16:1 cis, C17:1, C18:1 cis -9, C20:1, and total unsaturates in PCD, as well as linear decreases in C17:0 (P = 0.04) and C17:1 (P < 0.001) in brisket fat were observed when HS was fed. Levels of HS up to 14% of diet ary DM exerted no detrimental effect on the growth or feed efficiency of cattle as compared to cattle fed a standard barley-based finishing diet. Including HS in the diet had both positive (increased CLA content) and negative (increased trans and saturated fats) effects on fatty acid profiles of beef tissues. Key words: Beef, conjugated linoleic acid, full-fat oilseed, hemp seed, tissue fatty acids
Genetic correlations among indicator traits for carcass composition measured in yearling beef bulls and finished feedlot steers
Authors: Bergen R. , Miller S. P. , Wilton J. W.
Published: April 2011

Genetic correlations were examined among 10 live growth and ultrasound traits measured in yearling beef bulls (n = 2172) and four carcass traits measured in crossbred finished feedlot steers (n = 1031). Heritabilities ranged from 0.13 (bull ultrasound longissimus muscle width) to 0.83 (yearling bull hip height). Genetic correlations indicated that selecting yearling bulls for increased growth rate and hip height would lead to higher carcass weight, increased longissimus muscle area and reduced levels of carcass marbling in steers. Bull ultrasound fat depth was positively associated with both carcass fat depth and marbling score. Most ultrasound longissimus muscle size measurements in bulls were positively associated with each other and with carcass longissimus muscle area in steers, but the magnitude of the genetic correlation with carcass measurements depended on the bull longissimus muscle size trait in question. This suggests that longissimus muscle shape in bulls may be related to carcass weight, fat and muscle traits in steers. Results confirm that while ultrasound is a valuable tool for the genetic improvement of carcass traits in beef cattle, genetic correlations between live bull ultrasound and steer carcass traits less then unity suggest that selection would benefit from multiple trait evaluations in situations where reliable carcass data are available. Key words: Ultrasound, beef carcass, heritability, genetic correlation
The accuracy of measuring backfat and loin muscle thicknesses on pork carcasses by the Hennessy HGP2, Destron PG-100, CGM and ultrasound CVT grading probes
Authors: Pomar C. , Marcoux M.
Published: April 2011

Research was undertaken to evaluate the accuracy of different grading probes measuring backfat (F) and loin muscle thicknesses (M). Thus, 270 pig carcasses were selected according to a 2 × 3 × 3 factorial arrangement. Gender (barrows and gilts), fat thickness at the Canadian grading site (< 15.75, 15.75 to 19.75 and > 19.75 mm), and hot carcass weight (75.5 to 81.8, 81.9 to 86.2 and 86.3 to 92.7 kg) were the main factors. The Hennessy (HGP2), Destron (PG-100) and CGM optic probes and the CVT ultrasound probe with two transducers [PCA-5049, 172 mm (CVT-1) and PCB-5011, 125 mm (CVT-2)] were evaluated. Grading measures were compared to the equivalent measures taken in a digitized image. The F and M precision was evaluated in terms of random bias (ED). Hennessy F and CVT-1 M had the lower ED. For F measurements, CGM, Destron, CVT-2 and CVT-1 ED was respectively, 1.65, 1.72, 1.78 and 2.14 times greater than Hennessy ED. For M measurements, ED of CVT-2, CGM, DPG and Hennessy was 1.02, 1.84, 2.03 and 2.20 times greater than CVT-1 ED. Measures of the intercostal muscles were not reliable in any of the probes able to take that measure. Key words: Pork, carcass grading, grading probes, HGP2, PG-100, CGM, CVT
Impact of B-vitamin supply on major metabolic pathways of lactating dairy cows
Authors: Girard C. L. , Matte J. J.
Published: April 2011

Knowledge of the major nutrient requirements of dairy cows has increased substantially during the past decades. Little is known, however, about the importance of the roles played by B vitamins. Since most of those vitamins act as essential cofactors in energy, protein and lipid metabolism, it is likely that as milk yield increases, the demand for these cofactors also increases. The supply of B vitamins from dietary sources and synthesis by the ruminal microflora is generally sufficient to avoid deficiency symptoms, but could be insufficient for optimizing metabolic efficiency, production, composition and the nutritional quality of milk in high-producing dairy cows. Results from recent experiments show how the supply of three B vitamins — folic acid, biotin and vitamin B12 — affects major metabolic pathways. Supplementary biotin has frequently been reported to increase milk yield but has a limited effect on milk composition. Folic acid supplements have been found to increase milk and milk protein yields in multiparous cows without affecting dry matter intake when vitamin B12 supply was adequate. An insufficient vitamin B12 supply blocked those effects but they can be restored through vitamin B12 supplementation. Supplemental vitamin B12 and biotin increased milk and milk protein yields without changing dry matter intake. Vitamin B12 utilization by tissues increased in cows fed supplementary folic acid simultaneously; plasma glucose also increased in these cows but plasma biotin decreased. From these findings, it appears that, in high-producing dairy cows, especially in early lactation, the strong competition for nutrients that occurs between gluconeogenesis, methylneogenesis and protein synthesis increases the amount of folic acid, vitamin B12 and biotin required to maintain metabolic efficiency, especially when the nutrient supply is limited. These observations emphasize the need to review the paradigm according to which B-vitamin supply by ruminal microflora cannot be limiting in dairy cow. Key words: Dairy cow, B vitamins, folic acid, vitamin B12, biotin, lactation, metabolism
Folic acid and vitamin B12 in reproducing sows: New concepts
Authors: Matte J. J. , Guay F. , Girard C. L.
Published: April 2011

In pig nutrition, the present gaps in the information on B-complex vitamins have important implications for empiricism and disparities in dietary recommendations. This is particularly true for folic acid (B9) and vitamin B12. Recent studies suggest that the beneficial effects of B9 on sow prolificacy may be due to enhanced embryo development and survival. Embryo synthesis of estrogens and uterine secretions of prostanoids and cytokines during attachment appear to be key factors in vitamin B9 regulation of embryo development. Nevertheless, embryo and uterine responses to B9 are often more pronounced in multiparous sows than in gilts. This parity effect on B9 responses can be attributed to the metabolic interaction with another vitamin, specifically B12. The two vitamins are essential for modulating the transfer of one-carbon groups for protein and DNA synthesis, methylation and gene expression. The metabolic pathway involved is the remethylation of methionine from an intermediary metabolite, homocysteine. A deficiency in B9 or B12 mayinduce a local or systemic accumulation of homocysteine, a powerful pro-oxidant known to impair embryo development. It appears that B12 status, which is about two times lower in gilts than in multiparous sows, could be a limiting factor for the action of vitamin B9 on uterus and embryo metabolism during the first pregnancy. Vitamin B12 status is particularly critical since, in early gestation, the sow uterus drains off a massive amount of B12, representing two to three times the B12 plasma pool. Dietary B12, at levels 10 times higher than recommended, have been found to maximize B12 status and minimize homocysteine accumulation in first parity sows. It appears that an optimum B9:B12 ratio, which has yet to be estimated, would enable vitamin B9 to have full beneficial effects on sow prolificacy. In the future, it is likely that there will be an even greater need for updated information on the requirements for B-complex vitamins given the “dietary fine tuning” that is necessary for the highly producing pigs that have been selected in recent decades. Key words: Folic acid, vitamin B12, reproduction, pig
Choline metabolism in high-producing dairy cows: Metabolic and nutritional basis
Authors: Baldi A. , Pinotti L.
Published: April 2011

Choline, the beta-hydroxyethyltrimethylammonium ion, is a strong base containing a trimethylated quaternary nitrogen. Choline occurs widely in biological materials as the compound itself, as acetylcholine and as various phospholipids. In feed ingredients and crude unprocessed fat sources, most choline is present as phosphatidylcholine (lecithin). Although soybean, soybean meal, rapeseed meal, fish meal and dried yeast are relatively rich sources of choline, the bioavailability of choline in these feedstuffs is only moderate. In dairy ruminants, choline is extensively degraded in the rumen. For this reason, dietary choline contributes insignificantly to the choline body pool, and methyl group metabolism is generally conservative with a relatively low rate of methyl catabolism and an elevated rate of de novo synthesis of methyl groups via the tetrahydrofolate system. Gluconeogenic precursors are the primary sources of the new methyl groups. Depending on energy balance and physiological state, such precursors can be deficient in ruminants. In situations of glucose imbalance, for example at the onset of lactation in the dairy cow, choline may become a limiting nutrient for milk production, owing to the extra demand for methyl groups. Furthermore, choline is a lipotropic substance and it may optimize the balance between fat retained and fat metabolized by the liver, thereby improving lipid metabolism in general. The data reviewed in this paper are consistent with these assumptions and support the fact that choline supplementation for dairy cows, in a form protected from ruminal degradation, may improve methyl group metabolism and the status of other nutrients, including vitamin E. Key words: Choline, methyl groups, methionine, dairy cows, rumen-protected choline
Response of nursery pigs to diets with increasing levels of raw peas
Authors: Friesen M. J. , Kiarie E. , Nyachoti C. M.
Published: April 2011

Five corn-soybean-based diets were formulated to contain 0, 15, 20, 25, or 30% raw peas and fed for 35 d to ninety-six 21-d-old pigs. Raw peas were included at the expense of corn and soybean meal. Increasing levels of raw peas depressed daily gain (P = 0.07), feed intake (P = 0.04) from days 21 to 56. Specifically, pigs fed diet with 25% peas had 19 and 25% lower average daily gain (ADG) and average daily feed intake (ADFI), respectively, than pigs fed the diet with 0% peas. The body weight (BW) was also linearly reduced (P = 0.10) on day 56. However, diets did not affect feed efficiency. Key words: Growth performance, peas, pig
Meat quality and fatty acid composition of pasture-finished beef steers fed barley and soybeans
Authors: Duynisveld J. L. , Charmley E. , Mir P.
Published: April 2011

The effect of supplemention on the performance, carcass characteristics, meat quality, and fatty acid composition of pasture-finished cattle was studied. Thirty-two steers were assigned to four treatments in a randomized block design. Treatments were: totally mixed ration (TMR) [confinement-fed total mixed ration (60% grass silage, 40% rolled barley], pasture only (rotationally grazed temperate mixed pasture); pasture plus barley (the same pasture plus 4.5 kg DM hd-1 d-1 rolled barley) and pasture plus soybeans (the same pasture plus 1.8 kg DM hd-1 d-1 whole roasted soybeans). Steers were slaughtered after 105 d on test. Tissue samples were collected at slaughter for analysis of meat quality and fatty acid content. Dry matter (DM) intakes were greater for TMR-fed cattle (P < 0.05). Among the pasture-fed cattle those fed barley (P < 0.05) consumed more total DM than those given pasture alone. Rates of BW gain were higher for TMR-fed steers than those fed pasture only (P < 0.05). Carcass weights and dressing percentage were similar across all treatments. Feeding barley or soybeans on pasture increased backfat thickness (P < 0.05), but the pasture-only cattle had greater loin eye area (P < 0.05). Pasture-only beef had more thaw drip loss (P < 0.05) and less cooking drip loss (P < 0.05) than TMR-fed beef. Evaporative cooking losses were greater in beef from unsupplemented pasture than from barley- or soybean-supplemented pasture (P < 0.05). Pasture-only beef had 25% more polyunsaturated fatty acids and 37% greater cis-9, trans-11 conjugated linoleic acid (CLA) concentrations in longisimus thoracis (l. thoracis) tissue than TMR-fed beef (P < 0.05). Among pasture-fed cattle, soybean supplementation increased C18:2 concentration by 34% (P < 0.05), while barley reduced C18:3 concentration by 8% (P < 0.05) in l. thoracis tissue. Soybean supplementation increased cis-9, trans-11 CLA concentration by 30% (P < 0.05) in l. thoracis tissue over pasture only. Beef finished on pasture has higher levels of beneficial fatty acids than TMR-fed beef, with few differences in meat quality. Supplementation on pasture improves animal performance, but barley has some negative effects on beneficial fatty acids in meat. Key words: Pasture, steers, fatty acids, conjugated linoleic acid
Nutrient digestibility, performance and carcass traits of growing-finishing pigs fed diets containing dried wheat distillers grains with solubles
Authors: Thacker P. A.
Published: April 2011

Seventy-two pigs were fed graded levels of wheat distillers grains with solubles (DDGS). During the growing period, gain, intake and nutrient digestibility declined (P < 0.01) as wheat DDGS increased. During the finishing period, performance was unaffected by wheat DDGS. At slaughter, dressing percentage and loin lean declined (P <0.01). Key words: Wheat distiller's dried grains with solubles, pigs, performance, digestibility, carcass traits
Role of serine in maintaining blood glucose levels o f broilers fed all-vegetable diets (R3)
Authors: Leeson A. S. , Lee E. H. , Leeson S.
Published: April 2011

Supplementing an all-vegetable diet with milk-powder, casein or serine resulted in increased blood glucose. Birds fed serine were also heavier than those fed a conventional diet or an unsupplemented all-vegetable diet. Birds fed all-vegetable diets may be more prone to hypoglycemia. Key words: Broiler, blood glucose, spiking mortality syndrome
A new look at energy discounts: using published studies to calculate discounted net energy values for dairy cows fed ad libitum
Authors: Robinson P. H.
Published: April 2011

Correct assessment of the energetic density of a diet fed to dairy cows is fundamental to accurate prediction of performance. Feeding experiments using lactating Holstein cows fed ad libitum, as reported by North American research facilities in peer-reviewed publications since 1990 in which the actual NEl density of the diet could be calculated from performance, and three dietary energy prediction systems [i.e., NRC (1989), NRC (2001) and an approach developed at the University of California at Davis (UCD)] were used to determine if the NEl discount (i.e., depression) in diets above maintenance (M) energy intake (i.e., 1 ×M) is linear or curvilinear. The principle used was that the expected NEl of the diets could be estimated using the three systems (at 3 ×M ), as well as the NEl calculated from observed performance of the cows, and the deviation (or difference) between the actual and estimated dietary NEl density could be regressed against the actual NEl output (×M) to determine the form of the expected decline in the NEl density of the diet as the energy output (relative to maintenance energy intake) of the cows increased. Results show that output of NEl (×M) is not a predictor of the deviation of the actually calculated NEl level of the diet vs. that estimated by any system. This was unexpected, as all three NEl estimation systems presume a linear decline in the deviation as level of NEl output (×M) increases. In contrast to NEl output (×M), intake of DM (g kg-1 body weight) was a weak predictor (r2 = 0.36 to 0.39 depending on system) of the diet NEl density deviation. The best predictors of diet NEl deviation in all three systems were DM intake (g kg-1BW) and NEl output (×M) combined, where r2 values were much higher (0.76 to 0.79), and there was little evidence of prediction bias in any system. Results suggest that the NEl density of a diet is a function of the inherent characteristics of the diet (i.e., its intrinsic digestibility), its level of consumption, and the genetic merit (and/or stage of lactation ) of the cows that eat it. The lack of a relationship between the deviation of the actually calculated vs. predicted NEl concentration shows that the three NEl prediction equations examined are fundamentally incorrect in their assumption that the NEl concentration of diets declines as the NEl output (×M) of the cows consuming them increases. However, the inaccurate estimates of the actual NEl densities by the systems can be corrected by application of appropriate equations that consider the anticipated level of DM intake and NEl output. Key words: Discount, net energy for lactation
Comparitive efficacy of five anthelmintics against trichostrongylid nematodes in sheep
Authors: Saddiqi Hafiz Abubakar , Jabbar Abdul , Iqbal Zafar , Babar Wasim , Sindhu Zia-ud-Din , Abbas Rao Zahid
Published: April 2011

The efficacy of levamisole, ivermectin and three different preparations of oxfendazole, applied at the recommended rate, were evaluated in flocks of sheep kept at two farms in Thal desert, Pakistan. Sixty animals on each farm were selected randomly on the basis of their weight and egg count of more than 150 eggs per gram of faeces. Three preparations of oxfendazole (fendamex, oxazole, syatamex), levamisole and ivermectin were given to five groups while one untreated group was kept as control. Faecal egg counts, faecal egg count reduction test, postmortem worm count and copro-culture were performed to assess the efficacy of selected anthelmintics. Levamisole and ivermectin preparations reduced (P ≤ 0.05) prevalent species of gastrointestinal nematodes in both flocks. Oxfendazole preparations exhibited low efficacy and some gastrointestinal nematodes (Haemonchus and Trichostrongylus) were suspected for resistance against these preparations, with resistance more pronounced in oxazole followed by systamex and fendamex. It was concluded that all oxfendazole preparations had low efficacy with suspicion for anthelmintic resistance while levamisole and ivermectin had reasonable effectiveness against prevalent gastrointestinal nematodes of sheep kept in Thal desert, Pakistan. Key words: Anthelmintic, resistance, gastrointestinal nematodes, sheep, Pakistan
Effects of sunflower oil in barley grain-based finishing diets on growth and carcass quality of feedlot steers
Authors: Baah J. , Ivan M. , Hristov A. N. , Mir P. S. , McAllister T. A.
Published: April 2011

High linoleic acid sunflower oil (HLSO) was included at 0, 3, 6, or 9% [dry matter (DM) basis] in barley-based finishing diets offered to 60 steers fed individually (n = 15 per dietary treatment). Trends toward improved average daily gain (ADG) (by 13% with 6% HLSO; quadratic, P = 0.08) and feed efficiency (by 7%, linear, P = 0.09) were observed. Steers tolerated 9% HLSO with no adverse effect on performance. Key words: Carcass characteristics, growth performance, linoleic acid, sunflower oil
Core body temperature monitoring with passive transponder boluses in beef heifers
Authors: Small J. A. , Kennedy A. D. , Kahane S. H.
Published: April 2011

Experiments were conducted over 82 d (Nov. 04 to Jan. 24, 49°N, mean ambient temperature -3.6 to -12.6 ± 1.6°C) to determine the effects of fever, photoperiod and pen setup on the rate (MR) and frequency (MF) with which heifers were monitored and the body (rumen) temperatures (BTr) obtained with a cattle temperature moniotoring system (MaGiiX). Magnetic, inductively coupled full duplex radio-frequency identification (RFID) transponder boluses containing thermistors were administered per os to 72 heifers (7.9 ± 0.5 mo of age and 283 ± 23 kg body weight) housed in one of four pens, in outdoor shed-lot facilities, each with a panel reader co-located with the waterbowl. A mixed ration (59% dry matter) was provided at 1500 daily. Fencing was arranged within pens for water motivated (WM) acquisitions during exps. 1 (Initial), 2 (Fever) and 3 (Photoperiod), or for either WM or activity motivated (AM) acquisitions during exp. 4 (Pen setup). Overall, most heifers were monitored daily (Mode MR 100%), several times perday (MF 7.8 ± 0.5), mostly during the afternoon and evening rather than night and morning 6-h periods, and BTr (37.8 ± 0.2°C, range 22 to 42°C) were usually lower (P < 0.05) for the afternoon than night. A 2°C increase in mean BTr caused by fever was detected (P < 0.05) when monitoring was scheduled rather than unscheduled. Extended (16h) in contrast to natural (8h) photoperiod increased (P < 0.05) evening MR (96.8 vs.83.5 ± 1.9%) and MF (3.8 vs. 2.5 ± 0.2), and morning-BTr (38.0 vs. 37.4 ± 0.11°C). Pen setup for AM in contrast to WM acquisitions increased (P < 0.05) MR and MF and BTr (by 1°C) in all periods of the day. The technology has excellent potential for non-invasive monitoring of BTr in heifers. Key words: Radio-frequency identification, cattle, transponder bolus, body temperature, rumen
Impact of feeding fermentable proteins and carbohydrates on growth performance, gut health and gastrointestinal function of newly weaned pigs
Authors: Jeaurond E. A. , Rademacher M. , Pluske J. R. , Zhu C. H. , de Lange C. F. M.
Published: April 2011

Feeding fermentable carbohydrates (FC) to weanling pigs may reduce the negative impact of proteolytic fermentation on gastrointestinal health and function. A total of 144 newly weaned pigs [6.23 kg body weight (BW); six pens per treatment; six pigs per pen) were used to determine the interactive effects of feeding additional fermentable protein (FP) and FC on growth performance, gastrointestinal function and intestinal health. Dietary treatments, based on a 2 × 2 factorial arrangement, were: (1) basal diet (control); (2) control + 10% poultry meal (PM) as FP source; (3) control + 5% beet pulp (BP) as FC source; and (4) control + 10% PM and 5% BP. Diets were formulated to be similar in digestible energy (DE) and digestible amino acid contents. In general, no interactive effects of FC and FP were observed (P > 0.10). During the 3-wk post-weaning period, feeding FP reduced average daily gain (ADG) (242 vs. 269 g d-1; P < 0.05), while FC increased ADG (269 vs. 243 g d-1; P < 0.05). Overall, feed intake did not differ between treatments (P > 0.10). On days 14 and 28 post-weaning, Clostridia spp. counts in colon contents, counts of white cells and segmented neutrophils in blood were lowered (P < 0.05) by feeding FC. Blood urea nitrogen was increased by feeding FP (9.5 vs. 6.5 mg dL-1; P < 0.05), while ammonia concentration in colon contents was lowered by FC (154 vs. 193 µg mL-1) (P = 0.06). Among biogenic amines, levels of tyramine (140 vs. 304 nmol g-1 DM) and spermidine (174 vs. 219 nmol g-1 DM) in colon contents were lowered (P < 0.05) by FC. Acetic, proprionic and butyric acid contents in colon contents were increased by feeding FC, while valeric and caproic acid content decreased by feeding FP (P < 0.05). Feeding FC and FP had no effect (P > 0.10) on colon histology, pH, fecal consistency score and organ weights. Results suggest that FP and FC have independent effects on newly weaned pigs, while effects appear partly related to changes in gut microbiota. Key words: Enteric fermentation, fiber, gastrointestinal function, protein, pigs
Review: Current knowledge on mammary blood flow, mammary uptake of energetic precursors and their effects on sow milk yield
Authors: Farmer C. , Trottier N. L. , Dourmad J. Y.
Published: April 2011

Dietary availability of nutrients to the mammary gland is a major limiting factor for sow milking potential. Nutrient availability to the udder is estimated by measuring mammary arteriovenous differences, which are affected by blood flow as well as circulating concentrations of nutrients. Mammary blood flow can be measured either directly or indirectly. Even though it is influenced by numerous factors, such as time since feeding, postural behavior, vasoactive substances, ambient temperature and litter size, authors report that the amount of plasma required to produce 1 kg of milk for a litter of 12 pigs ranges from 490 to 1050 L at peak lactation. Blood glucose is the major precursor for lactose synthesis and reported extraction rates of glucose by the mammary gland vary between 20 and 31%. Other metabolic precursors, such as triglycerides, phospholipids, acetate, propionate and lactate are also used for milk synthesis. There exists a discrepancy between estimates of energetic efficiency depending on the type of study conducted (metabolism vs. mammary balance). Endocrine status of the sow may affect mammary nutrient availability. There still exists a gap in our knowledge on relative mammary uptakes of energetic compounds other than glucose and on glucose transporter systems in porcine mammary tissue. The need for such information is of particular importance due to the increased milking demands currently made on lactating sows. Key words: Blood flow, lactation, mammary gland, nutrient uptake, sows
Effect of lecithin with or without chitooligosaccharide on the growth performance, nutrient digestibility, blood metabolites and pork quality of finishing pigs
Authors: Kim Won-Tae , Shinde Prashant , Chae Byung Jo
Published: April 2011

Two experiments were conducted to evaluate the effect of dietary lecithin with or without chitooligosaccharide (COS) on the performance, blood metabolites, pork cholesterol, fatty acid composition and quality of finishing pigs. In exp. 1, 36 pigs (Landrace × Yorkshire × Duroc, 84.5 ± 0.60 kg initial body weight) were fed lecithin at 0, 2.5 or 5.0% of the diet. Lecithin improved average daily gain (16%) and feed conversion ratio, and did not affect apparent nutrient digestibility. On day 28, lecithin decreased serum total and low density lipoprotein (LDL) cholesterol (34 and 77%, P = 0.016), and increased serum triglyceride (P = 0.048). Lecithin did not affect carcass characteristics and pork quality, but increased myristic and α-linolenic acid and reduced palmitoleic acid in pork. Experiment 2 involved 108 pigs (85.0 ± 0.76 kg initial body weight) in a 2 × 2 factorial arrangement of treatments, wherein two levels of lecithin (low, 2.5 and high, 5.0%) and COS (0.0 and 0.1%) were used. Addition of COS in diets containing lecithin reduced pork cholesterol (16.4%) and oleic acid (28.3%), and did not affect performance, nutrient digestibility, blood metabolites and pork quality. In conclusion, these results suggest that lecithin improved the growth performance of finishing pigs and inclusion of COS reduced the amount of cholesterol in pork. Key words: Lecithin, COS, performance, nutrient digestibility, pork quality
AC Domain hard red spring wheat
Authors: Townley-Smith T. F. , Czarnecki E. M.
Published: April 2011

AC Domain hard red spring wheat (Triticum aestivum L.) exhibited high levels of pre-harvest sprouting tolerance and is adapted to the Canadian prairies. In Manitoba, the grain yield of AC Domain was 3.4 to 7.4% higher than the check cultivars, while in Saskatchewan it was 3.3 to 8% lower. AC Domain had shorter, stronger straw than the check cultivars. AC Domain is eligible for all grades of the Canada Western Red Spring (CWRS) wheat class. Key words: Triticum aestivum L., cultivar description, grain yield and protein, resistance to pre-harvest sprouting, leaf and stem rust
Relationship of seed quality traits for greenhouse-grown versus field-grown high erucic acid rapesseed: Is seed quality trait selection for greenhouse-grown seed worthwhile?
Authors: Bahrani J. , McVetty P. B. E.
Published: April 2011

A study of the relationship of seed quality traits for greenhouse-grown and field-grown seed samples was conducted. Early generation high erucic acid rapeseed (HEAR) cross progeny were grown in the greenhouse, selfed and then the selfed seeds were grown in the field at the University of Manitoba. The oil, protein, erucic acid and glucosinolate concentrations of greenhouse-grown versus field-grown seed samples were compared. There were differences (P ≤ 0.01) between the means of all seed quality traits for greenhouse-grown versus field-grown seed samples. The mean oil, protein and erucic acid concentrations of field-grown seed samples were higher than for greenhouse-grown seed samples. In contrast, the mean glucosinolate concentration of greenhouse-grown seed samples was higher than for field-grown seed samples. Rank correlations between greenhouse-grown seed samples and field-grown seed samples for all seed quality traits were significant but moderate in magnitude. Selection for oil, protein, erucic acid and glucosinolate concentration in greenhouse-grown seed samples dramatically increased the number of high seed quality F4 families in the field and was successful for all seed quality traits. It is concluded that seed quality selection in greenhouse-grown seed samples is worthwhile and that this procedure could lead to greater efficiencies in Brassica plant breeding programs. Key words: Rapeseed (Brassica napus L.), oil, protein, erucic acid, glucosinolates
Wild blueberry response to phosphorus applied to Prince Edward Island soils
Authors: Sanderson K. R. , Eaton L. J.
Published: April 2011

Pressure on growers to protect the environment and reduce input costs has increased the need to more effectively use fertilizers. Two experiments were conducted to evaluate the response of wild blueberries to soil-applied P on loamy sand to sandy loam Orthic Podzol soils in Prince Edward Island over three cropping cycles from 1992 to 1997. The sites had soil test (Mehlich-3) P levels from 33 to 44 µg P g-1, which are rated as L- for blueberries in the PEI Soil and Feed Testing Laboratory Standards. Treatments consisted of soil-applied P at 0, 10, 20, 30 and 40 kg ha-1 applied to the same plots in the sprout year in each of three consecutive cropping cycles. There was a positive linear relationship between application rate of P and extractable soil P and leaf tissue P concentration. Over the 6 yr of the study, soil extractable P increased on average 1.1 µg P g-1 for each kg of soil-applied P compared with the control where no soil P was applied. Increases in levels of tissue P concentration were less dramatic. Plant growth and yields were not affected by rate of soil-applied P fertilizer. This study indicates that on sites with low soil test P, application of soil-applied P did not benefit wild blueberry production. By conserving P fertilizer, growers can also reduce the potential for environmental damage caused by the buildup of soil P. Key words: Phosphorus, soil and leaf nutrient concentrations, wild blueberry, Vaccinium angustifolium Ait., yield
Inter Simple Sequence Repeat (ISSR) markers to assess genetic diversity and relatedness within strawberry genotypes
Authors: Debnath S. C. , Khanizadeh S. , Jamieson A. R. , Kempler C.
Published: April 2011

The goal of this study was to determine the level of genetic diversity and relatedness among 16 strawberry (Fragaria H ananassa Duch.) cultivars and 11 breeding lines developed in Canada, using Inter Simple Sequence Repeat (ISSR) markers. Seventeen primers generated 225 polymorphic ISSR-PCR bands. Cluster analysis by the unweighted pair-group method with arithmetic averages (UPGMA) revealed a substantial degree of genetic similarity among the genotypes ranging from 63 to 77% that were in agreement with the principal coordinate (PCO) analysis. Geographical distribution for the place of breeding program explained only 1.4% of total variation as revealed by analysis of molecular variance (AMOVA). The ISSR markers detected a sufficient degree of polymorphism to differentiate among strawberry genotypes, making this technology valuable for cultivar identification and for the more efficient choice of parents in current strawberry breeding programs. Key words: Fragaria × ananassa, DNA fingerprinting, multivariate analysis, breeding, genetic similarity