Lacombe Research Center

Lacombe, Canada

Lacombe Research Center

Lacombe, Canada
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Stewart M.,Agresearch Ltd. | Webster J.R.,Agresearch Ltd. | Stafford K.J.,Massey University | Schaefer A.L.,Lacombe Research Center | Verkerk G.A.,DairyNZ
Journal of Dairy Science | Year: 2010

Changes in autonomic nervous system (ANS) activity are one of the first phases of a stress response, but they are rarely used to assess the welfare of farm animals. Eye temperature measured using infrared thermography (IRT) is proposed as an indicator of ANS activity because it may reflect changes in blood flow in the capillary beds of the conjunctiva. The aim was to determine whether epinephrine infusion would initiate eye temperature changes in calves. Sixteen 4-mo-old Friesian calves (124 ± 5. kg) were assigned randomly to receive a jugular infusion of either epinephrine (4 μg/kg per min for 5. min) or saline. Eye temperature (°C), heart rate (HR), and HR variability (HRV) were recorded from 15. min before infusion until 10. min after it was completed. Blood samples collected via jugular catheter were assayed for epinephrine, norepinephrine, and cortisol concentrations, and packed cell volume (PCV) was measured. No changes in any variable were observed with the saline infusion. Plasma epinephrine concentrations increased 90-fold with epinephrine infusion, which was associated with a decrease in eye temperature of 1.4 ± 0.05°C. During epinephrine infusion, plasma norepinephrine concentrations decreased by half and HR decreased by 9.3 ± 3.3 beats/min. The HRV measure, the root mean square of successive differences, increased by 49.7 ± 9.2. ms, indicating a compensatory increase in parasympathetic activity. After epinephrine infusion, plasma cortisol concentrations increased by 10.4 ± 1.7 ng/mL and PCV was higher (38 vs. 31 ± 0.1%, epinephrine vs. saline, respectively). These results support the hypothesis that changes in eye temperature are mediated by the sympathetic component of the ANS. Infrared thermography is a noninvasive method to assess ANS activity for evaluating welfare of cattle. © 2010 American Dairy Science Association.

Jin W.,University of Alberta | Dodson M.V.,Washington State University | Moore S.S.,University of Alberta | Basarab J.A.,Lacombe Research Center | Guan L.L.,University of Alberta
BMC Molecular Biology | Year: 2010

Background: MicroRNAs (miRNAs), a family of small non-coding RNA molecules, appear to regulate animal lipid metabolism and preadipocyte conversion to form lipid-assimilating adipocytes (i.e. adipogenesis). However, no miRNA to date has been reported to modulate adipogenesis and lipid deposition in beef cattle.Results: The expression patterns of 89 miRNAs including four bovine specific miRNAs in subcutaneous adipose tissues from three groups of crossbred steers differing in backfat thickness were compared using qRT-PCR analysis. Eighty-six miRNAs were detectable in all samples, with 42 miRNAs differing among crossbreds (P < 0.05) and 15 miRNAs differentially expressed between tissues with high and low backfat thickness (P < 0.05). The expression levels of 18 miRNAs were correlated with backfat thickness (P < 0.05). The miRNA most differentially expressed and the most strongly associated with backfat thickness was miR-378, with a 1.99-fold increase in high backfat thickness tissues (r = 0.72).Conclusions: MiRNA expression patterns differed significantly in response to host genetic components. Approximately 20% of the miRNAs in this study were identified as being correlated with backfat thickness. This result suggests that miRNAs may play a regulatory role in white adipose tissue development in beef animals. © 2010 Jin et al; licensee BioMed Central Ltd.

Menon D.G.,University of British Columbia | Bennett D.C.,University of British Columbia | Schaefer A.L.,Lacombe Research Center | Cheng K.M.,University of British Columbia
Poultry Science | Year: 2014

Many emu farms are located in areas lacking processing facilities that can handle these birds. Thus, long-distance shipping of birds to an abattoir is necessary. Two experiments were conducted, wherein emus were transported in a modified horse trailer for 6 h to an abattoir. Changes in the indices of stress and metabolic homeostasis (hematology, serum biochemistry, enzymes, and body temperature and weight) were used to evaluate the physiological response to transport. The activities of enzymes alanine aminotransferase, aspartate aminotransferase, and creatine kinase increased significantly (P < 0.001) from pretransport to slaughter, indicating muscle cell wall damages. The body temperature of emus was significantly (P < 0.001) increased from 37.0 to 39.6°C after transport in experiment 1 and from 37.2 to 38.9°C in experiment 2. Transport resulted in significant weight loss in both experiments (P < 0.001; 2.1 ± 0.2 kg vs. 0.6 ± 0.2 kg) and posttransport resting at lairage led to slight regaining (P < 0.01) of BW. Oral administration of supplements before and after transport was effective in protecting against muscle damage and faster recovery of BW losses during lairage. The clinical findings were suggestive of the incidence of exertional rhabdomyolysis and thus underlined the need for careful handling and improved transport conditions of emus. © 2014 Poultry Science Association Inc.

Menon D.G.,University of British Columbia | Bennett D.C.,University of British Columbia | Schaefer A.M.,Lacombe Research Center | Cheng K.M.,University of British Columbia
Poultry Science | Year: 2013

Blood profiling is a helpful tool in detecting the health status, metabolic diseases, nutritional deficiencies, and welfare of animals. Body weights, body temperatures, hematological and serum biochemical parameters, enzymes, and electrolytes in both sexes of farm emus at the beginning of their breeding season (November in Canada), were determined. The reference interval for each analyte was also calculated. Emus have lower body temperatures (37.2 ± 0.2) than other poultry species. There was no significant between-sex difference in BW, body temperature, and all the hematological and enzyme parameters measured. However, females had significantly (P < 0.001) higher serum calcium, phosphorus, albumin, total protein, globulin, and triglyceride levels than males, probably in preparation for egg laying. We also examined our findings in light of their sex-role reversal in incubation and brooding. Contrary to other avian species in which only females incubate and brood, there was no sex difference in the hematological and enzyme parameters measured in emus. We found that emus are similar to other ratite species with respect to the changes in protein, globulin, triglyceride, and calcium levels. The findings from our study contribute to the database for reference emu hematological and serum enzyme, metabolite, and electrolyte values. © 2013 Poultry Science Association Inc.

Li M.,University of Alberta | Zhou M.,University of Alberta | Adamowicz E.,University of Alberta | Basarab J.A.,Lacombe Research Center | Guan L.L.,University of Alberta
Veterinary Microbiology | Year: 2012

Currently, knowledge regarding the ecology and function of bacteria attached to the epithelial tissue of the rumen wall is limited. In this study, the diversity of the bacterial community attached to the rumen epithelial tissue was compared to the rumen content bacterial community using 16S rRNA gene sequencing, PCR-DGGE, and qRT-PCR analysis. Sequence analysis of 2785 randomly selected clones from six 16S rDNA (~1.4. kb) libraries showed that the community structures of three rumen content libraries clustered together and were separated from the rumen tissue libraries. The diversity index of each library revealed that ruminal content bacterial communities (4.12/4.42/4.88) were higher than ruminal tissue communities (2.90/2.73/3.23), based on 97% similarity. The phylum Firmicutes was predominant in the ruminal tissue communities, while the phylum Bacteroidetes was predominant in the ruminal content communities. The phyla Fibrobacteres, Planctomycetes, and Verrucomicrobia were only detected in the ruminal content communities. PCR-DGGE analysis of the bacterial profiles of the rumen content and ruminal epithelial tissue samples from 22 steers further confirmed that there is a distinct bacterial community that inhibits the rumen epithelium. The distinctive epimural bacterial communities suggest that Firmicutes, together with other epithelial-specific species, may have additional functions other than food digestion. © 2011 Elsevier B.V.

Mujibi F.D.N.,University of Alberta | Moore S.S.,University of Alberta | Nkrumah D.J.,Pfizer | Wang Z.,University of Alberta | Basarab J.A.,Lacombe Research Center
Journal of Animal Science | Year: 2010

This study sought to assess whether residual feed intake (RFI) calculated by regressing feed intake (DMI) on growth rate (ADG) and metabolic mid-BW in 3 different ways led to similar estimates of genetic parameters and variance components for young growing cattle tested for feed intake in fall and winter seasons. A total of 378 beef steers in 5 cohorts were fed a typical high energy feedlot diet and had free-choice access to feed and water. Feed intake data were collected in fall or winter seasons. Climate data were obtained from the University of Alberta Kinsella meteorological station and Vikings AGCM station. Individual animal RFI was obtained by either fitting a regression model to each test group separately (RFIC), fitting a regression model to pooled data consisting of all cohorts but including test group as a fixed effect (RFIO), or fitting a regression to pooled data with test group as a fixed effect but within seasonal (fall-winter or winterspring) groups (RFIS). Two animal models (M1 and M2) that differed by the inclusion of fixed effects of test group or season, respectively, were used to evaluate RFI measurements. Feed intake was correlated with air temperature, relative humidity, solar radiation, and wind speed (-0.26, 0.23, 0.30, -0.14 for fall-winter and 0.31, -0.04, 0.14, 0.16 for winter-spring, respectively), but the nature and magnitude of the correlations were different for the 2 seasons. Single trait direct heritability, model likelihood, direct genetic variance, and EBV accuracy estimates were greatest for RFIC and least for RFIO for both M1 and M2 models. A significant genetic correlation was also observed between RFIO and ADG, but not for RFIC and RFIS. Including a season effect (M2) in the genetic evaluation of RFIO resulted in the smallest heritability, model LogL, EBV accuracy, and largest residual variance estimates. These results, though not conclusive, suggest a possible effect of seasonality on feed intake and thus feed efficiency. © 2010 American Society of Animal Science. All rights reserved.

Nassu R.T.,Lacombe Research Center | Uttaro B.,Lacombe Research Center | Aalhus J.L.,Lacombe Research Center | Zawadski S.,Lacombe Research Center | And 2 more authors.
Food Chemistry | Year: 2012

Colour stability is a very important parameter for meat retail display, as appearance of the product is the deciding factor for consumers at time of purchase. This study investigated the possibility of extending appearance shelf-life through the combined use of packaging method (overwrapping - OVER, modified atmosphere - MAP, vacuum skin packaging - VSP and a combination of modified atmosphere and vacuum skin packaging - MAPVSP) and antioxidants (vitamin E enriched beef). Retail attributes (appearance, lean colour, % surface discolouration), as well as colour space analysis of images for red, green and blue parameters were measured over 18 days. MAPVSP provided the most desirable retail appearance during the first 4 days of retail display, while VSP-HB had the best colour stability. Overall, packaging type was more influential than α-tocopherol levels on meat colour stability, although α-tocopherol levels (>4 μg g-1 meat) had a protective effect when using high oxygen packaging methods. © 2012 Elsevier Ltd. All rights reserved.

Juarez M.,Agriculture and Agri Food Canada | Dugan M.E.R.,Agriculture and Agri Food Canada | Aldai N.,Agriculture and Agri Food Canada | Basarab J.A.,Lacombe Research Center | And 3 more authors.
Meat Science | Year: 2012

In order to investigate the effects of increasing beef n-3 fatty acid content and the protective effects of vitamin E antioxidant activity on meat quality characteristics, 80 feedlot steers were fed 4 different diets (control, high vitamin E, 10% ground flaxseed or high vitamin E-10% ground flaxseed). While dietary treatments had no effect (P> 0.05) on meat composition or tenderness values, the increase in oxidation products was lower (P= 0.046) in meat from vitamin E supplemented steers and higher (P= 0.006) in meat from flaxseed fed animals. The increase in α-tocopherol tissue levels (P< 0.001) in meat from animals fed flaxseed and increased dietary vitamin E resulted in the lowest drip loss values (P= 0.013). As expected, display time had a large effect on retail traits in both steaks and patties (P< 0.001). While retail traits of steaks were not affected by the dietary treatments (P> 0.05), feeding flaxseed decreased (P< 0.05) ground beef retail scores, which were not corrected by higher levels of dietary vitamin E. Finally, although no effect (P> 0.05) was observed among treatments for sensory attributes in steaks, the correlations of a combined n-3:α-tocopherol ratio against retail and sensory attributes (P< 0.05) suggest that increased n-3 fatty acids levels require increased dietary antioxidants, such as vitamin E to avoid negative effects on meat quality from a loss in oxidative stability. © 2011.

Basarab J.A.,Lacombe Research Center
Animal : an international journal of animal bioscience | Year: 2013

Genetic selection for residual feed intake (RFI) is an indirect approach for reducing enteric methane (CH4) emissions in beef and dairy cattle. RFI is moderately heritable (0.26 to 0.43), moderately repeatable across diets (0.33 to 0.67) and independent of body size and production, and when adjusted for off-test ultrasound backfat thickness (RFI fat) is also independent of body fatness in growing animals. It is highly dependent on accurate measurement of individual animal feed intake. Within-animal repeatability of feed intake is moderate (0.29 to 0.49) with distinctive diurnal patterns associated with cattle type, diet and genotype, necessitating the recording of feed intake for at least 35 days. In addition, direct measurement of enteric CH4 production will likely be more variable and expensive than measuring feed intake and if conducted should be expressed as CH4 production (g/animal per day) adjusted for body size, growth, body composition and dry matter intake (DMI) or as residual CH4 production. A further disadvantage of a direct CH4 phenotype is that the relationships of enteric CH4 production on other economically important traits are largely unknown. Selection for low RFI fat (efficient, -RFI fat) will result in cattle that consume less dry matter (DMI) and have an improved feed conversion ratio (FCR) compared with high RFI fat cattle (inefficient; +RFI fat). Few antagonistic effects have been reported for the relationships of RFI fat on carcass and meat quality, fertility, cow lifetime productivity and adaptability to stress or extensive grazing conditions. Low RFI fat cattle also produce 15% to 25% less enteric CH4 than +RFI fat cattle, since DMI is positively related to enteric methane (CH4) production. In addition, lower DMI and feeding duration and frequency, and a different rumen bacterial profile that improves rumen fermentation in -RFI fat cattle may favor a 1% to 2% improvement in dry matter and CP digestibility compared with +RFI fat cattle. Rate of genetic change using this approach is expected to improve feed efficiency and reduce enteric CH4 emissions from cattle by 0.75% to 1.0% per year at equal levels of body size, growth and body fatness compared with cattle not selected for RFI fat.

Juarez M.,Agriculture and Agri Food Canada | Dugan M.E.R.,Agriculture and Agri Food Canada | Aalhus J.L.,Agriculture and Agri Food Canada | Aldai N.,Agriculture and Agri Food Canada | And 3 more authors.
Meat Science | Year: 2011

To elucidate the effects of dietary vitamin E with or without flaxseed on beef fatty acid composition, 80 feedlot steers were fed 4 diets: Control-E (451. IU. dl-α-tocopheryl acetate/head/day), Control. +. E (1051. IU. dl-α-tocopheryl acetate/head/day), Flax-E (10% ground) and Flax. +. E. Vitamin E had no effect on animal growth or carcass weight (p> 0.05), while flaxseed-fed steers had greater average daily gain (p= 0.007), final live weight (p= 0.005) and heavier carcasses (p= 0.012). Feeding flaxseed increased the total n-3 fatty acid content of beef and this response was further accentuated by the inclusion of high levels of vitamin E in the diet. Feeding flax increased levels of some 18:3n-3 partial hydrogenation products including c15- and t13/14-18:1 and several 18:2 isomers (p< 0.001) but decreased t10-18:1 (p< 0.001). Vitamin E enhanced intramuscular levels of 18:3n-3 and its biohydrogenation products leading to greater accumulations of total n-3 fatty acids in lean ground beef. The consequences of increasing the concentrations of partially hydrogenated products on human health have yet to be investigated. © 2011.

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