bluuebunny/crossref_metadata_2025 huggingface dataset:
Semen cryopreservation: Successes and persistent problems in farm species
Authors: Bailey J. , Morrier A. , Cormier N.
Published: April 2011

Artificial insemination has arguably been the most important practice contributing to the advancement of animal production. The numerous advantages of artificial insemination are augmented when the semen is cryopreserved and conserved for long periods. Unfortunately, the utility of cryopreserved semen is limited because for most mammals, even cattle, a considerable proportion of sperm loose their fertility during freezing-thawing. In many species , this loss of fertility is substantial, rendering cryopreserved semen impractical for routine use. Our goals are to characterize the nature of the sublethal sperm damage caused by cryopreservation, and to develop a method to improve the functional fertility of thawed semen. This review describes our theory that sperm are prematurely activated by cryopreservation (“cryo-capacitation”) and discusses strategies for preventing this damage. Key words: Sperm, artificial insemination, capacitation, fertility
Factors affecting embryo survival and strategies to reduce embryonic mortality in cattle
Authors: Bilodeau-Goeseels S. , Kastelic J. P.
Published: April 2011

Embryonic mortality in cattle is the death of the conceptus before Day 42 of pregnancy. Estimates of embryonic mortality varied greatly, ranging from 10 to 40% in first-service cattle to 65% in repeat-breeder cows. This paper reviews endogenous causes of embryonic mortality, including chromosomal abnormalities, inadequate corpus luteum function and the influence of follicular development on fertility. External causes of embryonic mortality, including heat stress and nutrition, are also reviewed; these factors act by modifying the follicular environment (thereby affecting oocyte quality) or by creating a hostile uterine environment. Strategies to reduce embryonic mortality, including good management practices and supplementation with progesterone or interferon-tau, are discussed. From a practical perspective, improved knowledge of the causes of embryonic mortality and regulation of follicular growth and corpus luteum function should result in the development of improved, cost-effective hormonal regimes that effectively synchronize estrus and ovulation and reduce embryonic mortality, thereby benefiting the cattle industry. Key words: Cattle, reproduction, fertility, embryo development, embryo mortality
Effects of feeding anionic products to non-lactating dairy cows on urine pH
Authors: Beauchemin K. A. , Bowman G. R. , Rode L. M. , von Keyserlingk M. A. G.
Published: April 2011

Anionic products (anionic salts, Bio-Chlor™, Nutri-Chlor™, and SoyChlor 16-7™ ) were fed to 12 non-lactating dairy cows and urine pH was monitored. The products differed in their effectiveness: anionic salts, Bio-Chlor, and Nutri-Chlor lowered urine pH, but SoyChlor was not effective. For cows fed once daily, checking urine pH 12 to 18 h after feeding is most likely to indicate nadir pH. Key words: Dietary cation-anion difference, urine acidification, urine pH, dairy cow, non-lactating
Effects of sunflower seed supplementation and different dietary protein concentrations on the ciliate protozoa population dynamics in the rumen of sheep
Authors: Ivan M. , Entz T. , Mir P. S. , Mir Z. , McAllister T. A.
Published: April 2011

The effects of feeding a linoleic acid-rich sunflower seed supplement and different levels of dietary protein on protozoal numbers and fermentation parameters in rumen fluid were determined in an 84-d experiment with rumen-cannulated sheep. The experiment comprised four treatments, two with low crude protein diets [12% of dietary dry matter (DM)] and two with high protein diets (16% of DM). On both low and high protein diets, one treatment was without (Control) and one with the sunflower seed (high linoleic acid variety 6150) supplement (14% of dietary DM). The four diets used were based on corn silage and corn grain, and soybean meal was used to achieve the desired concentration of dietary protein. The sheep were fully fed each morning and rumen fluid samples were taken 2 h later on various days of the experiment (daily during the first 14 d for enumeration of protozoa). In addition, rumen fluid was sampled at different hours after feeding on day 43 of the experiment. Results showed a protozoa-decreasing effect (P < 0.001) of sunflower seeds causing a decline in protozoa numbers after 2 d of supplementation. The effect of protein on protozoa numbers was dependent on the presence of sunflower seed supplement. Measurements on day 43 showed increased protozoa numbers (P < 0.05) and ammonia nitrogen concentrations (P < 0.001) due to higher dietary protein, and decreased protozoal numbers (P < 0.05) and ammonia nitrogen (P < 0.001) due to the sunflower seed supplement, without significant effects (P > 0.05) on volatile fatty acid concentrations. The linoleic acid-rich sunflower seed supplement was highly effective in reducing both protozoa numbers and ammonia nitrogen concentrations in rumen fluid. Key words: Rumen ciliate protozoa, sunflower seeds, dietary protein, sheep
Heritability and correlation estimates of Warner-Bratzler shear force and carcass traits from Angus-, Charolais-, Hereford-, and Simmental-sired cattle
Authors: Minick J. A. , Dikeman M. E. , Pollak E. J. , Wilson D. E.
Published: April 2011

Heritabilities and correlations of Warner-Bratzler shear force (WBSF), marbling score (MS), hot carcass weight (HCW),12–13th rib-fat (FAT), and ribeye area (REA) were calculated from 3360 Angus-, Charolais-, Hereford-, and Simmental-sired cattle in the C attleman’s Beef Board Carcass Merit Project. The heritabilities (± SE) for WBSF, MS, HCW, FAT, and REA were 0.34 ± 0.25, 0.43 ± 0.28, 0.73 ± 0.35, 0.16 ± 0.19, and 0.56 ± 0.31 in Angus; 0.43 ± 0.22, 0.30 ± 0.18, 0.21 ± 0.16, 0.35 ± 0.20, and 0.23 ± 0.16 in Charolais; 0.12 ± 0.11, 0.55 ± 0.22, 0.20 ± 0.14, 0.25 ± 0.15 and 0.34 ± 0.17 in Hereford; and 0.16 ± 0.14, 0.44 ± 0.20, 0.45 ± 0.20, 0.23 ± 0.16, and 0.30 ± 0.18 in Simmental. The genetic correlations, averaged across analysis type, for WBSF-MS, WBSF-HCW, WBSF-FAT, WBSF-REA, MS-HCW, MS-FAT, MS-REA, HCW-FAT, HCW-REA, and FAT-REA were -0.17, 0.32, -0.23, 0.30, 0.10, -0.17, 0.39, -0.15, 0.68, and -0.86 in Angus; -0.42, 0.77, 0.52, -0.05, -0.44, -0.22, -0.19, 0.66, -0.05, and -0.24 in Charolais; -0.43, -0.04, -0.33, 0.09, 0.08, 0.79, -0.14, -0.26, 0.50, and -0.38 in Hereford; and 0.55, 0.08, 0.62, -0.08, 0.30, 0.61, -0.14, 0.06, 0.65, and -0.48 in Simmental. Key words: Beef cattle, genetic parameters, carcass quality, tenderness
Characteristics and in situ degradability of whole crop faba bean, pea, and soybean silages
Authors: Mustafa A. F. , Seguin P.
Published: April 2011

The objective of this study was to determine the ensiling characteristics and ruminal nutrient degradabilities of faba bean (FS, Vicia faba L.), soybean (SS, Glycine max (L.) Merr.) and pea (PS, Pisum sativum L.) silages. Forages were harvested between the beginning- and full-seed stages and ensiled in mini-silos for 0, 2, 4, 16, and 45 d. Two lactating Holstein cows fitted with ruminal fistulae were used to determine ruminal nutrient degradabilities. Results showed that all silages went through a rapid fermentation as indicated by rapid decline in pH and sharp increase in lactic acid concentration within the first 2 d of ensiling. Extensive proteolysis took place between day 0 and day 4 post-ensiling as indicated by a significant reduction in true protein (TP) and a significant increase in non-protein nitrogen (NPN). During the 45 d of ensiling, TP decreased (P < 0.05) by 26, 31, and 45% while NPN increased (P < 0.05) by 82, 54, and 47% for FS, SS, and PS, respectively. Chemical analysis showed that the three 45-d silages contained a similar level of neutral detergent fiber (NDF, average 421 g kg-1). Crude protein (CP) was highest (P < 0.05) for FS, intermediate for SS, and lowest for PS. Distribution of protein fractions showed that soluble protein and NPN were highest (P < 0.05) for PS, intermediate for SS, and lowest for FS. Neutral (NDICP) and acid (ADICP) detergent insoluble protein levels followed an opposite order to that observed for soluble crude protein (SCP) and NPN. Results of the in situ study showed that SS and PS had a similar ruminal degradability of dry matter (average 68.8%) and CP (82.9%), which were higher (P < 0.05) than those of FS (66.2 and 79.4%, respectively). However, no differences in ruminal degradability of NDF (average 34.7%) were observed between the three legume silages. Key words: Silage, ensiling, forage quality, nutrient degradability
Training cattle to approach a feed source in response to auditory signals
Authors: Wredle E. , Rushen J. , de Passillé A. M. , Munksgaard L.
Published: April 2011

To help improve cow traffic in automated milking systems, we examined whether heifers could be trained to approach a feeder in response to a tone emanating from their collars. Eighteen dairy heifers were used in four experiments. Ten heifers were trained by operant conditioning. Eight of these heifers approached the feeder more frequently and with a shorter mean latency following the tone than in the control periods (P < 0.05). Four of the heifers were tested in a new location but none of the heifers approached the feeder following the tone. A further eight heifers were trained by classical conditioning. When tethered close to the feeder during training, no animals learned to approach the feeder in response to the tone. When four heifers were trained while loose in the pen and had a second tone that predicted an aversive treatment, the animals approached the feeder more often after the positive tone (P < 0.05). Operant conditioning can be used to train heifers to approach a feeder in response to an auditory signal. Classical conditioning procedures are less effective and the optimal training procedures need to be defined before implementation in automated milking systems. Key words: Dairy cattle, learning, conditioning, auditory signals, automatic milking systems
Use of synchrotron FTIR microspectroscopy to identify chemical differences in barley endosperm tissue in relation to rumen degradation characteristics
Authors: Yu P. , Christensen D. A. , Christensen C. R. , Drew M. D. , Rossnagel B. G. , McKinnon J. J.
Published: April 2011

Valier (feed-type) and Harrington (malting-type) barley differ in rumen degradation characteristics. Harrington, in contrasts to Valier, exhibits a high rate and extent of rumen degradation, which can lead to metabolic problems such as acidosis and bloat in ruminants. Traditional “wet” chemical analysis cannot detect biological differences between barley varieties due to destruction of endosperm structure during processing. Synchrotron Fourier transform infrared microspectroscopy (SR-FTIR) is capable of exploring the chemical makeup of intact plant tissue with high signal to noise ratio at spatial resolutions as fine as 3~10 µm. The objective of this study was to use SR-FTIR microspectroscopy to explore and identify chemical differences in the ultra-structural matrix of the endosperm tissue of the two barley varieties as related to differences in rumen degradation characteristics. The results showed that the infrared absorbance intensity (Log 1/R) of the starch and protein varied considerably between the two varieties, but were not statistically significant. Harrington had a wider range of starch to protein IR absorbance intensity ratio (1.406 to 10.119 vs. 1.419 to 4.274), suggesting that it is more heterogeneous than Valier in endosperm chemical makeup. Valier had a lower ratio of starch to protein IR absorbance intensity than Harrington (P < 0.05), which implies that the starch granules in Valier are more closely associated with the protein matrix. This close association may prevent the starch granules from being rapidly degraded in the rumen. This work shows that the chemical makeup of intact plant tissues can be carried out by SR-FTIR microspectroscopy at ultra-spatial resolution (10 × 10 µm). Key words: Synchrotron infrared microspectroscopy, feed chemistry, barley, rumen degradability
Factors affecting dry matter intake prepartum in relationship to etiology of peripartum lipid-related metabolic disorders: A review
Authors: Hayirli A. , Grummer R. R.
Published: April 2011

Transition from gestation to lactation is a tremendous challenge for dairy cattle and requires metabolic and hormonal adjustments. The periparturient period, particularly the last week of gestation, is characterized by a dramatic decline (20 to 40%) in dry matter intake (DMI) prior to parturition and a slow rate of increase in DMI after parturition. As a result of negative energy balance during the periparturient period, excessive fat mobilization in adipose tissue and inability of disposing fatty acids (F A) via β-oxidation and exporting triglyceride (TG) as very low density lipoproteins (VLDL) in the liver cause hepatic lipidosis. Controlling hepatic lipidosis, therefore, depends on either limiting non-esterified fatty acids (NEFA) uptake by the liver or increasing oxidation of FA and export of TG by the liver, or both. Results of studies regarding lipid metabolism in the liver to minimize lipidosis are controversial. Thus, until factor(s) limiting hepatic VLDL-TG export are identified, limiting fat mobilization from adipose tissue will play a key role in prevention of hepatic lipidosis and ketosis. Depression in DMI prior to parturition shifts metabolism from anabolism to catabolism. Animal factors such as parity and body condition score and dietary factors such as density of organic nutrients influence DMI. Particularly, increasing energy density of the transition cow diet, without causing acidosis, by supplemental nonstructural carbohydrate (NFC) increases DMI and serum insulin concentration, which suppress lipolysis in adipose tissue and favors anabolic status. In summary, level of DMI and magnitude of DMI depression prior to parturition are linked to the etiology of postpartum lipid-related metabolic disorders. Thus, easing transition from gestation to lactation by offering high dietary NFC in consideration with other factors allows cows to produce more milk, become healthier, and be rebred sooner during postpartum. Key words: Periparturient dairy cattle, dry matter intake, hepatic lipidosis, ketosis
Impact of feeding blends of organic acids and herbal extracts on growth performance, gut microbiota and digestive function in newly weaned pigs
Authors: Namkung H. , Li J. Gong M. , Yu H. , Cottrill M. , de Lange C. F. M.
Published: April 2011

One hundred eighty newly weaned pigs were used to inves tigate effects of feeding organic acids and herbal extracts on growth performance, gut morphology and microbiota, and immune response in newly weaned pigs during a 4-wk period. There were five dietary treatments: control, Acid 1 (acetic, propionic, phosphoric and citric acid; 1.1% inclusion), Acid 2 (Acid 1 + 1.0% lactic acid), herbal extracts (0.75% inclusion; containing cinnamon, thyme and oregano extract), and antibiotic (110 ppm lincomycin). As compared to the control, pigs on antibiotic and Acid 2 showed higher (P < 0.05) ADG only during week 2 post-weaning, whereas pigs on herbal extract showed lower (P < 0.05) ADG only during week 3 post-weaning. Fecal coliform counts were lower (P < 0.08) in pigs on Acid 1 and 2 on day 4 post-weaning and in pigs on antibiotic and herbal extract on day 14 post-weaning. Fecal lactobacilli counts were lower (P < 0.05) in pigs on antibiotic on day 14 post-weaning. Based on PCR-DGGE, treatment influenced the composition of gut microbiota. The pH of the colon was lower (P < 0.05) in pigs on acid treatments and serum IgG was lower (P < 0.05) in pigs on antibiotic. Dietary treatment did not affect (P > 0.10) intestinal morphology. These results show that the inclusion of antibiotic in the diet reduced the proliferation of both potentially harmful coliform bacteria and potentially beneficial lactobacilli in the pig’s gut, while herbal extract and organic acids appeared to reduce the proliferation of coliform bacteria. Blends of organic acids can serve as an alternative to in-feed antibiotics during the first few weeks post-weaning for pigs. Key words: Piglet, organic acids, herb, microbiota, immune response, intestinal morphology
Multiple trait estimates of genetic parameters for juvenile growth and calving traits in Canadian Angus cattle
Authors: Rasali D. P. , Crow G. H. , Shrestha J. N. B. , Kennedy A. D. , Brûlé-Babel A.
Published: April 2011

Two analyses, both with three calf body weights at birth (BW), weaning (WW) and yearling (YW), one including first calving date (CD1) using a four-trait model, and the other including calving date (CD) and interval (CI) in a five-trait model, were carried out for a pooled population of beef cattle from one herd in Manitoba (n = 3,601), three herds in Alberta (n = 779, 600 and 967) and one herd in Saskatchewan (n = 495) totaling 6442 calving records for years 1984 through 2001.
Individual free choice creep feed intake by suckling calves on range
Authors: Ralston B. J. , Olson M. E. , Garossino K. C. , McAllister T. A. , Milligan D. N. , Genswein B. M. A.
Published: April 2011

A 51-d study was conducted to determine creep feed intake by suckling beef calves (N = 51) on range. Daily mean attendance at the creep feeder was 21 ± 10.3%, (range 2 to 43%) and mean intake was 1009 ± 634.4 g calf-1 d-1 (range from 67 to 3424g calf-1 d-1). Creep feed intake and attendance by calves on range may be too variable to be considered an effective method of delivering pharmaceuticals. Key words: Creep feed, intake, calf, feeding behavior
Orally administered anti-Escherichia coli O157:H7 chicken egg yolk antibodies reduce fecal shedding of the pathogen by ruminants
Authors: Cook S. R. , Bach S. J. , Stevenson S. M. L. , DeVinney R. , Frohlich A. A. , Fang L. , McAllister T. A.
Published: April 2011

Spray-dried whole egg prepared from eggs laid by non-immunized hens (EG) or hens immunized with the C-terminal domain of Escherichia coli O157:H7 intimin (EG-IgY) was fed to experimentally inoculated sheep, to investigate the efficacy of orally administered polyclonal anti-E. coli O157:H7 antibodies (IgY) for reducing the duration and level of fecal shedding of E. coli O157:H7 by ruminants. Thirty Canadian Arcott ram lambs were orally inoculated on day 0 with 1010 colony-forming units (CFU) of a three-strain mixture of nalidixic acid-resistant E. coli O157:H7. On each of days 2, 3 and 4, the rams (n = 6) were fed 100 g of EG and/or EG-IgY in proportions of 100:0 (CON), 0:100 (HIGH), 50:50 (MED), or 75:25 (LOW). A fifth treatment (denoted variable, VAR) comprised feeding HIGH, MED and LOW on days 2, 3, and 4, respectively. Fecal samples collected on 19 occasions over 85 d (4 × in the first wk; 2×/wk for 3 wk; and 1×/wk for 9 wk) were assessed for E. coli O157:H7 by direct plating or enrichment and immunomagnetic separation. Throughout the 85 d, numbers of E. coli O157:H7 shed by the rams were lower (P < 0.001) in HIGH and MED than in CON, and the duration of shedding was shorter (P < 0.005) in HIGH than in CON. Fewer (P < 0.005) samples were culture-positive in HIGH than in CON. Oral dosing of specific IgY has potential to decrease the duration and level of fecal shedding of E. coli O157:H7 by ruminants. Key words: E. coli O157:H7, egg-yolk IgY, fecal shedding, immunotherapy, ruminants, sheep
Phosphorus status of lactating dairy cows fed total mixed rations containing 0.24% vs. 0.36% phosphorus
Authors: Shore K. V. , Odongo N. E. , Mutsvangwa T. , Widowski T. M. , Cant J. P. , Bettger W. J. , McBride B. W.
Published: April 2011

The effect of dietary P content on P balance was evaluated using 14 lactating dairy cows fed a corn silage based total mixed ration (TMR) containing either 0.24% P or 0.36% P. The animals were paired by calving date at dry-off with one cow from each pair randomly assigned to either dietary treatment. All cows were fed a common TMR containing 0.34% P prepartum, and then 0.41% P for 2 wk postpartum. Experimental diets were fed from 3 to 13 wk postpartum. Phosphorus balance was conducted at week 13 postpartum. Cows fed 0.36% P diet consumed more (P < 0.05) P than the 0.24% P diet cows (69.2 vs. 50.9 g d-1) and excreted more (P < 0.05) P in the faeces (49.1 vs. 25.7 g d-1). Phosphorus digestibility was lower (P < 0.05) for the 0.36% P diet than the 0.24% P diet (29.0 vs. 48.8%). Dry matter intake and milk yield were not (P > 0.05) affected by treatments. These results suggest that short-term P balance in lactating dairy cows can be maintained on a diet supplying 26% below National Research Council 2001 recommendations of P while reducing the amount of P excreted into the environment. Key words: Phosphorus balance, dairy cows, lactating, phosphorus requirement
Effect of lactitol, lactic acid bacteria, or their combinations (synbiotic) on intestinal proteolysis in vitro, and on feed efficiency in weaned pigs
Authors: Piva A. , Casadei G. , Gatta P. P. , Luchansky J. B. , Biagi G.
Published: April 2011

The purpose of the present study was to evaluate in vitro the intestinal microflora response to lactitol (LCT) as a non-digestible oligosaccharide (NDO) and/or to two swine lactic acid bacteria (LAB) isolates (Lactobacillus brevis and L. salivarius), and to select the most effective treatment to modulate intestinal fermentation in a subsequent growth study with weaning piglets. During a 24-h in vitro cecal fermentation, LCT alone or in combination with either bacteria isolate stimulated gas production rate (P < 0.05), while LAB isolates alone did not (P > 0.05). Both combinations of isolates with LCT reduced ammonia levels after 24 h by 26 and 31%, respectively (P < 0.05), while LCT alone was effective in keeping ammonia lower than the control only in the first 8 h (P < 0.05). All treatments increased (P < 0.05) the production of total volatile fatty acids. The most effective combination (LCT + L. salivarius) in vitro was selected to be used in a 49-d feeding experiment with weaned piglets (32 animals per group, eight piglets per cage, four cages per treatment). Feed efficiency was improved (13%) by LCT + L. salivarius (P < 0.05), while average daily gain and feed consumption were not affected (P > 0.05). These data substantiated the positive synergistic effect of the combination of an NDO with a LAB isolate as compared with the use of individual components in modulating the cecal microflora under in vitro conditions. This study showed that such combination may positively influence feed efficiency when fed to pigs. Key words: Swine, cecum, synbiotics, probiotics, prebiotics, lactitol, lactic acid bacteria
Physiological and behavioural responses to short-haul transport by stock trailer in finished steers
Authors: Booth-McLean M. E. , Schwartzkopf-Genswein K. S. , Brown F. A. , Holmes C. L. , Schaefer A. L. , McAllister T. A. , Mears G. J.
Published: April 2011

Nineteen British cross-bred steers (623 ± 10.6 kg) were transported in groups of four or five for 3 h and returned to their home pens. Jugular cannulas, heart rate (HR; BPM) monitors and radio transmitters were used to non-invasively collect physiological data. Heart rate (n = 13) was lower during highway travel (83.5 ± 3.15, P > 0.05) compared with pre-loading (118.9 ± 3.19, P < 0.01) and off-loading (97.5 ± 4.47) but was not different from travel in town (88.8 ± 2.90). Plasma cortisol concentration (µg dL-1, n = 16) increased from pre-loading (1.87 ± 0.28) to off-loading (3.10 ± 0.28, P < 0.02) and decreased to 1.16 ± 0.28 µg dL-1 by 1 h after off-loading (P < 0.001), a value not different from pre-loading levels. Body temperature measured at offloading was 0.19°C higher (P < 0.001) than at pre-loading. No differences in the time spent eating and ruminating were observed when compared between a 1-h period 1 d prior to transport and the same time of day post-transport (P > 0.50). Increases in HR (P < 0.01) and lying time (P < 0.001) post-transport compared with the days prior suggest cattle experienced some fatigue. Mild, short-term stress responses were observed in finished steers exposed to 3 h of transportation. Key words: Cortisol, heart rate, hematocrit, behaviour, steers, transportation
The effects of limit feeding a high-energy barley-based diet to backgrounding cattle in western Canada
Authors: Klinger S. A. , Campbell J. , Wildeman B. , Block H. , McKinnon J. J.
Published: April 2011

A series of three completely randomized design trials were conducted to compare the effects of a limit-fed high-grain diet relative with that of an ad libitum-fed high-forage diet on performance of growing cattle with similar total energy intakes. In trial 1, the ad libitum-fed high-forage diet was formulated to 1.58 and 0.98 Mcal NEm and NEg kg-1 DM. The high-grain diet was formulated to 1.91 Mcal NEm and 1.23 Mcal NEg kg-1 DM. Projected liveweight gains (1.22 kg d-1) and the amount of DM provided to the limit-fed high-grain cattle were based on the NEm and NEg equations for liveweight gain of large-frame steers (NRC 1984). A similar feeding regime was employed for trials 2 and 3; however, it was necessary to reduce energy intake equally after 30 d on feed to control weight gains. In trial 1, the limit-fed high-grain cattle had similar (P > 0.05) ADG and lower (P < 0.05) DMI than the ad libitum-fed high-forage cattle, leading to a 15.4% improvement (P < 0.05) in feed efficiency. Feed efficiency was improved (P < 0.05) by 16.9% in trial 2 and by 21.2% in trial 3 for the limit-fed high-grain cattle, primarily as a result of reduced (P < 0.05) DM intake and similar (P > 0.05) daily gains. Back fat accretion rates were greater (P < 0.05) in the limit-fed high-grain cattle, indicating differences in energy partitioning. The incidence of severe liver abscesses was greater (P < 0.05) for the limit-fed high-grain cattle in trial 2. These results indicate that limit feeding a high-grain diet to backgrounding cattle can be employed to target specific rates of gain and improve feed efficiency although managing acidosis to prevent liver abscesses may be an issue. Key words: Cattle, limit feeding, feed efficiency, liver abscesses
Supplementation of lactating ewes with a glucogenic preparation or β-carotene in mid- to late lactation, on subsequent milk yield and luteinizing hormone secretion
Authors: Brozos C. N. , Kiossis E. , Fthenakis G. C. , Tsousis G. , Boscos C.
Published: April 2011

The effects of a glucogenic preparation (Nutrimix®) or β-carotene (Rovimix® beta carotene) supplementation of ewes during mid- to late-lactation on their milk yield were assessed in a study where 66 Chios-breed ewes were allocated into three equal (n = 22) groups. Ewes in group A received daily a glucogenic preparation and those in group B β-carotene, starting 35 d before estrus synchronization until 7 d after artificial insemination (supplementation period); ewes in group C were untreated controls. The estrus cycle was synchronized and double AI was carried out 48 and 60 h after withdrawal of progestagen sponges. Milk yield was measured daily during the supplementation period. Blood samples were collected at 2-h intervals, from 28 to 54 h after sponge withdrawal; the concentration of plasma luteinizing hormone (LH) was measured. Increased milk yield was recorded after supplementation with the glucogenic preparation (P < 0.05), but not with β-carotene (P > 0.05). There were no differences in LH concentration during surge release in supplemented ewes; furthermore, there were no differences between groups in body weight and litter size. It is concluded that supplementation of ewes with a glucogenic preparation during mid- to late-lactation may lead to improved milk production. Key words: Sheep reproduction, milk yield, β-carotene, energy, luteinizing hormone
Grazing and the addition of white clover improves the nutritional quality of orchardgrass cultivars
Authors: Papadopoulos Y. A. , Martin R. C. , Fredeen A. H. , McRae K. B. , Price M. A.
Published: April 2011

Two experiments were conducted to determine the nutritional quality of orchardgrass (OG) cultivars under hay and rotational grazing systems during the first 2 production years. Crude protein content was higher and fibre content lower in OG managed as rotationally grazed pasture compared with that harvested as hay. The K:Ca + Mg ratio was reduced and Cu deficiency was ameliorated when OG swards contained white clover. Orchardgrass genotypic × sward management effects were also observed. Key words: Orchardgrass, management, potassium, genotypes, quality, pasture, hay
Behavioural and physiolgical thermoregulation in groups of pregnant sows housed in a kennel system at low temperatures
Authors: Andersen Inger Lise , Bøe Knut Egil , Hove Knut
Published: April 2011

The behavioural and physiological responses of pregnant sows to cold exposure in a kennel system were investigated. Ten groups, each of six pregnant sows, were housed over winter in a non-insulated building containing kennels. Lying posture, social thermoregulation, time spent inside the kennels and general activity were recorded in three 48-h periods with different diurnal room temperatures: cold (−9 to −1 °C), medium (0 to +3 °C) and warm (+4 to +9 °C). Blood samples were collected from two of the groups, and the concentrations of glucose, free fatty acids, total thyroxine (TT4) and free thyroxine (FT4) in the plasma were determined.The air temperature difference in between the surrounding room and the kennels increased with decreasing room temperature with a maximum of 12 °C at a room temperature of −10 °C. Activity level did not differ significantly between temperature periods (30.6 ± 1.1%). At all temperature periods, the sows spent between 80 and 90% of their time inside the kennels. The sows spent significantly more time eating/manipulating straw in the cold than in the medium and warm period (P = 0.038). Time spent lying on the belly in body contact with other sows inside the kennel increased significantly from 15.6% in the warm period to 20.3% in the medium period and 44.9 % in the cold period (P = 0.001). The two highest ranked individuals (rank 1 and 2) tended to spend more time inside the kennel than sows with rank order 4 to 6 (P = 0.059). At a diurnal room temperature of −8° C, the sows had a significantly higher level of (FT4) in the plasma than at higher temperatures (P < 0.001). The relationship between the other blood parameters and diurnal room temperature was difficult to interpret.This study suggests that kennels with straw give the sows good protection from climatic conditions, and that social thermoregulation in a micro environment is an important strategy to cope with low temperatures. At a diurnal room temperature of –8°C, however, the increase of FT4 in the plasma may indicate an increased metabolism and thus an increased energy requirement. Since low-ranking individuals spent less time inside the kennels than high-ranking sows, they probably had a greater heat loss. For practical application of the system, the kennel should thus be designed in a way that allows all individuals to get inside. Key words: Pregnant sows, thermoregulation, physiology, kennel, social rank order
Effect of particle size on in situ ruminal disappearances of pea (Pisumsativum) organic matter, proteins and starch in dairy cows
Authors: Bayourthe C. , Moncoulon R. , Enjalbert F.
Published: April 2011

Ruminal disappearance characteristics of OM, CP and starch relative to particle size of dehulled pea seeds were determined using the in sacco method. Fine grinding (≤502 µm) highly increased the rapidly CP and starch degradable fractions and the rate of degradation of these nutrients. Key words: Pea flour, particle size, rumen degradation, crude protein, starch
In vivo and in vitro lipogenesis and aspects of metabolism in ovines: Effect of environmental temperature and dietary lipid supplementation
Authors: Moibi J. A. , Christopherson R. J. , Okine E. K.
Published: April 2011

Twenty-four wether lambs were randomly allocated to six treatments to investigate the effect of temperature and dietary lipid supplements on fatty acid synthesis and metabolic activity in sheep. The treatments consisted of four groups exposed to either cold (0 °C) or warm temperature (+23 °C) and given ad libitum access to either a control barley-based diet or with lipid supplementation. Two other groups were placed on the dietary regimen at 0 °C, but pair-fed to intake of animals in the +23 °C environment. At 5 wk, fatty acid synthesis was measured by [1-14C]acetate incorporation into tissue lipids. Cold exposure and dietary lipid supplementation had no effect (P > 0.05) on in vivo fatty acid synthesis rates in either longissimus dorsi or the liver. In both subcutaneous and mesenteric adipose tissue depots, the rate of acetate incorporation into tissue lipid was not significantly affected by cold exposure. In the perirenal fat depot, cold exposure increased (P < 0.05) the rate of fatty acid synthesis, while lipid supplementation decreased (P < 0.05) the rate in all tissue adipose depots. In vitro, mesenteric and perirenal adipose tissues from cold pair-fed animals had higher (P < 0.05) rates of fatty acid synthesis compared to tissues from animals in the warm environment. However, there was no effect of dietary lipid supplementation in these two fat depots. Metabolic heat production, and energy and nitrogen excretion by animals were increased (P < 0.05) by cold exposure while lipid supplementation had the opposite effect (P < 0.05). The relationship between average daily gain and feed intake was linear at both warm and cold environments, but with higher (P < 0.05) average daily gain at all levels of intake in the cold compared to the warm environment. Results indicate that both environment and diet regulate metabolic activity in sheep. However, there were differences in lipogenic response by tissues to the treatments. Key words: Environmental temperature, dietary lipid, fatty acid synthesis, metabolic rate, sheep
Effect of a surfactant and exogenous enzymes on digestibility of feed and on growth performance and carcass traits of lambs
Authors: McAllister T. A. , Stanford K. , Bae H. D. , Treacher R. J. , Hristov A. N. , Baah J. , Shelford J. A. , Cheng K.-J.
Published: April 2011

The effects of Tween 80 on the stability and substrate binding capacity of two commercially available enzyme preparations were studied in vitro. After 1 wk of incubation, endoglucanase activity was higher (P < 0.05) in the presence of 0.02 or 0.2% (vol vol−1) Tween 80 than without this surfactant. Tween 80 increased (P < 0.05) protein binding both to filter paper and to cotton fibres. Digestibility and feedlot experiments were conducted with Dorset and Romanov × Suffolk lambs, respectively, given forage- and concentrate-based diets. The diets were untreated or sprayed with the enzyme preparations, Tween 80 or a mixture of both. With the concentrate diet, treatment with enzymes + surfactant reduced (P < 0.05) intake of feed dry matter and N, acid detergent fibre digestibility, N digestion and microbial N production, relative to treatment with either additive alone. Treating the concentrate diet with enzymes increased (P < 0.05) N retention (g d−1) by the lambs, as compared to untreated diet. With the forage diet, neutral detergent fibre digestibility was higher with Tween 80 alone than with enzymes + surfactant. In the feedlot experiment, treating the forage diet with surfactant reduced (P < 0.05) dry matter intake and daily gain, relative to untreated diet, and increased (P < 0.05) the number of days to finish. Feed conversion efficiency (gain feed−1) of lambs fed the concentrate diet was lower (P < 0.05) when the diet was treated with surfactant than with enzymes. Treating the concentrate diet with enzymes + surfactant increased (P < 0.05) the number of days required to finish the lambs. Although Tween 80 appeared to increase the stability and substrate binding capacity of enzymes in the laboratory, it did not enhance the effects of the enzymes on nutrient digestibility or growth performance in animal feeding studies. Key words: Enzymes, surfactants, sheep, lamb, digestion, growth
Genetic analysis of ten sheep breeds using microsatellite markers
Authors: Farid A. , O'Reilly E. , Dollard C. , Kelsey Jr. C.R.
Published: April 2011

The genetic variability of 257 sheep from 10 breeds; North Country Cheviot (NCC), Cheviot (CHE), Dorset (DOR), Suffolk (SUF), Scottish Blackface (SBF), Texel (TEX), Romanov (ROM), Finnish Landrace (FIN), Icelandic (ICE) and Red Masai (MAS) was assessed using 10 microsatellite loci. The average number of alleles per locus was 4.3 in ROM, 5.0 in MAS, and spanned a narrow range (5.4 to 6.0) in the other breeds. Estimates of expected heterozygosity (HE) of the breeds varied within 0.05 point of each other (0.62 in FIN to 0.67 in CHE), except for ROM (0.53) which was lower (P < 0.05) than those of the other breeds, and in MAS (0.57), which was lower (P < 0.05) than those of NCC, CHE and SBF. Estimates of observed heterozygosity (HO) of the breeds were the lowest in MAS, ROM and SUF (0.50 to 0.53) and the highest in NCC and CHE (0.64 and 0.67). The HE was greater (P < 0.01) than HO only in SUF. The results suggest that there have not been drastic losses of genetic variability in the intensely selected breeds. The low genetic variability of ROM was probably due to a small number of animals imported to North America. The British breeds (NCC, CHE, SUF, DOR, SBF) were genetically close to each other, as were the North European breeds (ROM, ICE, FIN). MAS was remotely related to the British breeds, but it was surprisingly close to the North European breeds. TEX was more closely related to the British breeds than to the North European breeds. More than 90% of 1000 simulated individuals from each breed were assigned to the correct breed, indicating that this panel of markers is useful for the identification of breed membership of individual animals, and could be used to protect the integrity of registered breeds. Key words: Sheep, genetic variability, genetic distance, microsatellites
Paternal influence on apoptosis, and expression of BCL2, BAX, TP53, heat shock protein-70 and interferon tau genes in bovine preimplantation embryo
Authors: Giritharan G. , Ramakrishnappa N. , Aali M. , Madan P. , Balendran A. , Singh R. , Rajamahendran R.
Published: April 2011

The bull effects on apoptosis, and BAX, BCL2, TP53, heat shock protein 70 (HSPA1A) and interferon tau (IFNT) gene expression in in vitro produced embryos were investigated. The degree of correlation of this effect with the 60- to 90-d non-return rates was also investigated. Standard in vitro fertilization and embryo culture were performed using frozen semen from six genetically unrelated bulls. Live, apoptotic, and dead cell percentages in blastocysts were determined, after staining with annexin V, propidium iodide, and bisbenzamide. BAX, BCL2, TP53, HSPA1A and IFNT gene expression levels in blastocysts were determined by RT-PCR. The non-return rate data for all experimental bulls were obtained from a local artificial insemination center. Apoptotic, live and dead blastomere percentages, and HSPA1A and IFNT expression levels in blastocysts were different (P < 0.01) among bulls. BAX, BCL2 and TP53 expression levels were not different among bulls. The non-return rate was highly correlated (P < 0.05) with BCL2 (r = -0.93) or the ratio of BAX to BCL2 (r = 0.84) gene expression. None of the other in vitro fertility parameters were correlated with non-return rate. This study concluded that the development, apoptosis, and HSPA1A and IFNT gene expression of in vitro produced embryos are influenced by individual bulls. Key words: Bovine, embryo, fertility, apoptosis, gene expression, interferon
Xylanase in diets for growing pigs and broiler chicks
Authors: Olukosi O. A. , Bedford M. R. , Adeola O.
Published: April 2011

Experiments designed to determine the effects of feeding graded levels of xylanase to 10-kg pigs (exp. 1) and 1-d old broiler chicks (exp. 2) are presented. Pigs received diet composed of corn, rye, wheat, and SBM for 28 d, whereas chickens were fed diet composed of rye, wheat, and SBM for 21 d. Six dietary treatments consisting of a control diet or control plus xylanase (in units kg-1) at 400, 800, 1600, 3200 or 32 000 were fed. Graded levels of xylanase had no effect on growth performance of 10-kg pigs. There were diet and age effects (P < 0.05) on digestibility of DM, CP, and Ca in pigs. Linear and quadratic responses (P < 0.05) in final weight, weight gain, and gain:feed of broiler chicks to graded levels of xylanase were observed in exp. 2. In exp. 2, the effect of xylanase became apparent (P < 0.05) at 800 U kg-1; there were no differences in response to xylanase at 3200 and 32 000 U kg-1. In conclusion, xylanase improved growth performance in 1-d-old broilers fed a diet composed of rye, wheat, and SBM but not in 10-kg pigs that received a diet composed of corn, rye, wheat, and SBM. Key words: Broiler chicks, non-starch polysaccharides, pigs, xylanase
Estimates of enteric methane emissions from cattle in Canada using the IPCC Tier-2 methodology
Authors: Ominski K. H. , Boadi D. A. , Wittenberg K. M. , Fulawka D. L. , Basarab J. A.
Published: April 2011

The objective of this study was to estimate enteric methane (CH4) emissions of the Canadian cattle population using the International Panel on Climate Change (IPCC) Tier-2 methodology. Estimates were then compared with IPCC Tier-1 methodology and data from Canadian research studies (CRS). Animal inventory data for the Canadian beef and dairy cattle herd was obtained from Statistics Canada. Information on cattle performance and feeding practices were obtained from provincial cattle specialists via a survey, as well as various published reports. Methane emissions from dairy and beef cattle in Canada for 2001 were 173 030 t yr-1 or 3.6 Mt CO2 eq. and 763 852 t yr-1 or 16.0 Mt CO2 eq., respectively, using Tier-2 methodology. Emissions for dairy cattle ranged from 708 t yr-1 in Newfoundland to 62 184 t yr-1 in Ontario. Emissions for beef cattle ranged from 191 t yr-1 in Newfoundland to 356 345 t yr-1 in Alberta. The national emission factors (kg CH4 yr-1) using IPCC Tier-2 were 73, 126, 90, 94, 40, 75, 63 and 56 for dairy heifers, dairy cows, beef cows, bulls, calves < 1yr, beef heifer replacements, heifers > 1 yr, and steers > 1yr, respectively. Emission factors (kg CH4 yr-1) for the above classes of cattle using IPCC Tier-1 were 56, 118, 72, 75, 47, 56, 47 and 47, respectively. The values were 15.1% higher to 25.3% lower than those obtained using IPCC Tier-2 methodology. When IPCC Tier-2 emission factors were compared with CRS, they were 12.3% lower to 32.6% higher than those obtained using the Tier-2 methodology. In conclusion, national estimates of enteric emissions from the Canadian cattle industry using Tier-1 and Tier-2 methodologies, as well as CRS, differ depending on the methodology used. Tier-2 methodology does allow for the inclusion of information other than population data, including feeding strategies, as well as duration of time in a given production environment. Additional research is required to establish the extent to which feed energy is converted to methane for those production scenarios for which there is no published data. Key words: IPCC Tier-2, IPCC Tier-1, enteric fermentation, cattle, methane, emission factor, methane conversion rate
Comparison of effects of Isotricha monofauna and total mixed fauna on dietary copper metabolism in lambs
Authors: Ivan and T. Entz M.
Published: April 2011

Three groups of 15 fauna-free (FF) lambs each were used to establish the effects of Isotricha sp. (IS) monofauna on the dietary copper (Cu) solubility in the stomach and on the concentration of Cu in the liver. One group remained FF (control) while the second and third groups were inoculated with IS and total mixed fauna (TF), respectively. All lambs were fed ad libitum a corn silage based diet for 168 d. Thereafter, the lambs were killed and livers, kidneys and stomachs were removed and sampled. Different fauna treatments did not affect (P > 0.1) growth performance parameters. In comparison with the FF sheep, both the TF and IS decreased (P < 0.05) the rumen solubility of Cu, but the decrease by IS (23%) was approximately half of that of TF (41%; P < 0.05). Similarly, TF and IS decreased the liver Cu concentration by 15% (P < 0.1) and 7.5% (P > 0.1), respectively. Although TF that significantly decreased the bioavailability of dietary Cu included IS and Dasytricha species, it appears that an absence of these Holotrich protozoa from the rumen protozoa population would not have a significant effect on the efficiency of the population to alleviate chronic copper toxicity in sheep. Key words: Isotricha, rumen, ciliate protozoa, lambs, copper
Effects of sodium bentonite supplements on growth performance of feedlot steers fed direct-cut or wilted grass silage based diets
Authors: Berthiaume R. , Ivan M. , Lafrenière C.
Published: April 2011

Forty crossbred steers (initial liveweight: 339 ± 41 kg) were assigned to four equal groups in a 98-d feeding experiment to determine the effects of sodium bentonite supplements (2% of dietary dry matter) on their growth performance. The steers were fed ad libitum a total mixed ration based on direct-cut (two groups) or wilted (two groups) grass silage. One group of steers fed the same silage received the diet without supplementation (control), while the second group received the diet with the sodium bentonite supplement. The steers were housed in pens with electronic headgates in an unheated enclosed feedlot. Feed intake was recorded throughout the experiment and weighing conducted every 2 wk. Apparent digestibilities of dietary components were determined with four steers in a parallel 4 × 4 Latin square experiment. Feed intake, average daily gain (ADG) and the efficiency of feed utilization were higher (P < 0.05) in steers fed wilted than in those fed the poorly fermented direct-cut grass silage. Bentonite increased (P = 0.04) ADG in steers fed the direct-cut grass silage, but in those fed the wilted grass silage ADG was virtually the same for both the control or the bentonite-supplemented steers. Except for energy, digestibility of nutrients was superior (P ≤ 0.05) in the wilted than in the direct-cut grass silage, but there were no effects (P > 0.05) of bentonite. It was concluded that it may be useful to supplement poorly fermented direct-cut silage diets with sodium bentonite, but not those based on wilted grass silage. Key words: Feedlot steers, sodium bentonite, grass silage, growth performance
Energy and nitrogen utilisation of sow colostrum and milk by the piglet
Authors: Dividich Jean Le , Marion Julia , Thomas Françoise
Published: April 2011

Twenty-four newborn piglets were used to evaluate the digestibility of sow colostrum and milk and the efficiency of milk utilisation by the piglet. Within a litter, four piglets were allotted to one of the four treatments: killed at birth, or bottle-fed sow colostrum for 30 h and sow milk thereafter at the rate of 100, 200, or 300 g kg-1 d-1. Piglets were killed on day 8. Faeces and urine were daily collected and heat production (HP) was determined by indirect calorimetry on days 6 and 7, each day during three successive periods of 105–110 min. Energy retention (ER) was calculated as the difference between metabolisable energy intake (ME) and HP. ER was also determined over the 8-d period using the comparative slaughter (CS). There was no effect of level of feeding on energy and nitrogen digestibility. Milk energy digestibility and metabolisability (ME/GE × 100) and nitrogen digestibility were 98.2 ± 1.2 (SEM), 96.8 ± 1.4 and 98.3 ± 1.3%, respectively. Corresponding values for colostrum were lower (P < 0.01), averaging 95.2 ± 2.8, 92.6 ± 3.1 and 95.3 ± 2.9%, respectively. Efficiency of using milk ME for ER determined by indirect calorimetry or CS was similar and averaged 0.72 ± 0.02. The energy cost of 1 kJ of protein deposition was 1.77 (± 0.04) kJ (efficiency, 0.56), whereas the energy cost of 1 kJ of fat deposition was not different to 1 kJ. Key words: Piglet, colostrum, milk, energy, nitrogen