Search

Knowing the demographics and interests of incoming animal science students is important in structuring effective learning experiences. For this purpose, students in Animal Science and Veterinary Science First Year Seminar courses were surveyed as to their species and career interests. As animal science industries have clearly biased gender distributions, we expected gender to be correlated with species and career interests among freshmen students majoring in Animal Science at South Dakota State University. Students surveyed had a strong interest in beef cattle (cow/calf and feedlot sectors), horses, and companion animals. The least interest was indicated for poultry, goats, and zoo animals. Of career interests, animal breeding, reproduction, and farming received the most interest. Most students were female (68.2%). Males were more likely to be interested in the feedlot sector of beef production, while females were more likely to be interested in goats, horses, companion, and zoo animals (P<0.05). Males were also more interested in careers in agronomy and the feeds industry, while females were more interested in equine related careers and working in zoos (P<0.05). Gender differences in species and career interests are largely in agreement with gender distributions within animal science industries. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine whether altered maternal energy supply during mid-gestation results in differences in muscle histology or genes regulating fetal adipose and muscle development. In total, 22 Angus cross-bred heifers (BW=527.73±8.3 kg) were assigned randomly to the three dietary treatments providing 146% (HIGH; n=7), 87% (INT; n=7) or 72% (LOW; n=8) of the energy requirements for heifers from day 85 to day 180 of gestation. Fetuses were removed via cesarean section at day 180 of gestation and longissimus muscle (LM) and subcutaneous fat were collected and prepared for analysis of gene expression. Samples from the LM and semitendinosus (ST) were evaluated for muscle fiber diameter, area and number. The right hind limb was dissected and analyzed to determine compositional analysis. Fetal growth and muscle histology characteristics of the LM and ST were similar among treatments. Preadipocyte factor-1 expression was up-regulated in fetal LM (P<0.05) of HIGH fetuses as compared with INT, whereas LOW fetuses showed increased CCAAT/enhancer-binding protein-β (C/EBP-β) expression in LM as compared with INT (P<0.05). Peroxisome proliferator-activated receptor γand C/EBP-α did not differ as a result of dietary treatment in LM or subcutaneous fat samples. There was a tendency for increased expression of fatty acid synthase in LM of LOW fetuses as compared with INT (P<0.10). Myogenin was more highly expressed (P<0.05) in LM of the LOW fetuses, whereas μ-calpain expression was increased in the HIGH treatment compared with INT. A tendency for increased expression of IGF-II was observed for both LOW and HIGH fetuses compared with INT (P<0.10). Expression of stearoyl-CoA desaturase, myoblast determination protein 1, myogenic factor 5, myogenic regulatory factor-4, m-calpain, calpastatin, IGF-I and myostatin was similar between treatments. Collectively, these results suggest that fetal growth characteristics are not affected by the level of maternal nutritional manipulation imposed in this study during mid-gestation. However, differences in expression of fetal genes regulating adipose and muscle tissue growth and development could lead to differences in postnatal composition and warrants further investigation. [ABSTRACT FROM PUBLISHER]

The objective of this study was to estimate genetic variability of Mycobacterium avium ssp. paratuberculosis infection in US Holsteins. Blood and fecal samples were collected primarily from daughters of 12 bulls in their second or third lactation. Routine disease testing of the sires documented that they were not infected. Herds without a "suspect" or positive ELISA (sample/ positive ratio ≥ 0.10) or positive fecal culture test were deleted from the data set. The remaining 4,603 cows from 238 herds and 46 sires were used to estimate heritability of M. paratuberculosis infection. Heritability was estimated with 3 Johne's disease diagnostic tests: 1) fecal culture alone, 2) serum antibody ELISA alone, and 3) both tests (combined) with a positive animal defined as all animals with either a positive fecal culture or ELISA test. Four statistical models were used to estimate heritability: 1) linear (ELISA), 2) threshold (fecal culture and combined), 3) ordered threshold (ELISA), and 4) bivariate linear-threshold (ELISA-fecal culture). A sire model and Bayesian approach using Markov chain Monte Carlo methods were used in each case. Heritability of infection based on the fecal culture test was 0.153 [posterior standard deviation (PSD) = 0.115]. Heritability with the ELISA was 0.159 (PSD = 0.090) with a linear model and 0.091 (PSD = 0.053) with an ordered threshold model. Heritability of the combined tests was 0.102 (PSD = 0.066). Heritability estimates of fecal culture and ELISA with the bivariate model varied slightly from estimates obtained with the univariate models (0.125 and 0.183, respectively), with a corresponding increase in precision (PSD = 0.096 and 0.082, respectively). This study demonstrates that exploitable genetic variation exists in dairy cattle for M. paratuberculosis infection susceptibility. [ABSTRACT FROM AUTHOR]

The difference between the methods of amylase determination lies the use of different substrates and in the final product of reaction. There are three methods in use: 1) amyloclastic method (determination of decreases in iodine-starch color); 2) saccharogenic method (determination of increases of reducing substances); 3) chromogenic method (splitting of semisynthetic substrates). Each method determines a certain set of amylolytic enzymes splitting glycogen or starch and differs from each other by the quantity of substrates being split, the quantity of the final product as well as the specific isoenzyme tested. Moreover, the groups of enzymes determined by the different methods differ in availability and properties of enzyme inhibitors. Amylolytic enzymes (pancreatic) determined by splitting semi-synthetic substrates have minimal inhibitors and are demonstrated by increases of serum amylase as seen in acute and exacerbation of chronic pancreatitis. Amylases possessing inhibitors may be of significance in diagnosing of chronic pancreatitis. Increase of amylase activity in blood indicates only the acuteness of the process but not the severity of the disease. Such increases can be observed as well in acute or active processes in the hepato-biliary tract, e.g., active liver cirrhosis, acute or exacerbation of chronic cholecystitis, and in patients after cholecystectomy. Two amylase inhibitors were determined in serum: in diluted serum (DAI) and in serum incubated with trypsin (TAI). Amylase inhibitors increase in patients with chronic pancreatitis. In exacerbation of pancreatitis the inhibitors are significantly depressed. [ABSTRACT FROM AUTHOR]