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This group meets yearly for one-day meetings. The 2013 meeting was sponsored by Nutreco Canada, Inc., Guelph, ON, Canada; ADM, Decatur, IL, USA; Cargill Animal Nutrition, Elk River, MN, USA; Ajinomoto Heartland, Inc., Chicago, IL, USA; Adisseo, Alpharetta, GA, USA; Lallemand Specialties, Inc., Milwaukee, WI, USA and Evonik Industries AG, Hanau, Germany. It was held on July 7 at the Hyatt Regency Indianapolis, One South Capital Avenue, Indianapolis, Indiana, USA, prior to the ADSA/ASAS Joint Annual Meeting. Summaries of the papers presented follow. Each summary has been peer reviewed and edited for clarity. The person who presented the paper is identified with an e-mail address.

As we approach the 21st century, it is appropriate to re-evaluate the sectional coverage of this scientific journal. Having done this over the course of the past 10 to 11 months, and having observed all proprieties of the Canadian Society of Animal Science, we hereby disclose that a new section is being added to the Canadian Journal of Animal Science. This new section is named: "Cellular and Molecular Biology". Dr. Michael V. Dodson of Washington State University (USA) is the section's first Associate Editor. Members of the Society and participants of the worldwide scientific community are welcome to submit scientific articles for inclusion in this section through the normal channels outlined in the journal's instructions to authors. Because this is the inaugural issue for the new section, papers from six different laboratories are included, covering the topics: cellular and molecular aspects of leptin, cellular and molecular biology of muscle growth and development, oocyte development, genetic markers, and molecular biology of the calpain system. As time passes we will encourage other laboratories to write papers, especially if initial submittals are slow, but we expect that a majority of future papers will be non-solicited "data" papers. As always, authority for style, scope and content resides with the Journals Policy Subcommittee and ultimately with the membership of the Canadian Society of Animal Science. Consequently, should there be any constructive criticism by Society membership about the new section as it has been founded, we will consider fine-tuning the section. Key words: Cellular and molecular biology

Velleman, S. G., Shin, J., Li, X. and Song, Y. 2012. Review: The skeletal muscle extracellular matrix: Possible roles in the regulation of muscle development and growth. Can. J. Anim. Sci. 92: 1–10. Skeletal muscle fibers are surrounded by an extrinsic extracellular matrix environment. The extracellular matrix is composed of collagens, proteoglycans, glycoproteins, growth factors, and cytokines. How the extracellular matrix influences skeletal muscle development and growth is an area that is not completely understood at this time. Studies on myogenesis have largely been directed toward the cellular components and overlooked that muscle cells secrete a complex extracellular matrix network. The extracellular matrix modulates muscle development by acting as a substrate for muscle cell migration, growth factor regulation, signal transduction of information from the extracellular matrix to the intrinsic cellular environment, and provides a cellular structural architecture framework necessary for tissue function. This paper reviews extracellular matrix regulation of muscle growth with a focus on secreted proteoglycans, cell surface proteoglycans, growth factors and cytokines, and the dynamic nature of the skeletal muscle extracellular matrix, because of its impact on the regulation of muscle cell proliferation and differentiation during myogenesis.

Meiotic maturation in mammalian oocytes is initiated during fetal development, arrested for several years in some cases, then completed at the time of ovulation. Although the mechanisms involved in oocyte meiotic arrest and meiotic resumption are not fully understood, new players and roles have recently been identified. This paper reviews the role of follicle cells, as well as the role of the cyclic adenosine 3', 5'-monophosphate (cAMP) pathway, in the maintenance of meiotic arrest. Potential mechanisms by which luteinizing hormone (LH) signals meiotic resumption are also reviewed. New findings on the role of adenosine monophosphate-activated kinase (PRKA), as well as the effects of culture medium composition on meiosis in vitro, are also discussed. From a practical perspective, improved understanding of the mechanisms involved in the control of meiosis will facilitate better control of the process in vitro resulting in increased developmental competence and increased efficiency of in vitro embryo production procedures. Key words: Bovine, oocyte, meiosis, cAMP

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

The objective of this paper is to review the utilization and outcome of reproductive biotechnologies in dairy cattle. Embryo transfer and IVF have their respective limits that influence their impact on a genetic improvement program. Embryo transfer is efficient and profitable in an artificial insemination breeding and selection program and IVF has great potential. Development of markers highly correlated with various economic traits will progressively be added to the present schemes to make them even more powerful. Key words: Reproductive technologies, embryo transfer, IVF, dairy cows, genetic

Calcineurin (Cn; protein phosphatase 2B) is a calcium-activated phosphatase that is highly conserved among eukaryotes. Calcineurin dephosphorylates a wide variety of substrates making it a versatile second messenger for intracellular calcium signals in many tissues. In muscle, Cn transduces signals that determine fiber type, hypertrophy, and commitment to the myogenic lineage. Calcineurin-mediated fiber transitions of fast to slow involve the nucleocytoplasmic shuttling of the transcription factor, NFAT. Less is known about the Cn-mediated signaling pathways that promote muscle hypertrophy and expression of the fast phenotype, although they are undoubtedly intertwined with a variety of other signaling pathways. This paper reviews Cn-dependent signaling in muscle with special emphasis on the role of Cn in mediating fiber type transitions and muscle hypertrophy. To open the door on the role and extent of Cn-mediated signaling in livestock, evidence is presented that in callipyge lambs Cn actively mediates muscle hypertrophy in a fiber type-specific manner. Increased understanding of Cn-dependent signaling in livestock will enhance our ability to control and select for extent of muscling and meat quality attributes. Key words: Calcineurin, signal transduction, muscle, review

This paper discusses the new animal drug approval process regulated by the Center for Veterinary Medicine (CVM), Food and Drug Administration (FDA) of the United States. The Center for Veterinary Medicine of FDA considers two criteria in ensuring the human food safety of edible animal products: i) safety of the chemical residues and ii) for antimicrobial products, microbiological safety including changes in bacterial pathogen load and resistance pattern. The hazard associated with animal drug products of non-carcinogenic compounds is assessed by conducting a standard battery of toxicology test, whereas the hazard from the carcinogenic potential of compounds is evaluated based on structure, results of genetic toxicity tests, and toxicology studies. Post approval monitoring is carried out to ensure that the animal drugs are being used properly after their approval. Particular concern is given to those eliciting an "acute" toxic reaction at relatively low levels. The other aspect of food safety regulated by CVM of FDA is microbiological safety, especially to antimicrobial drugs used at subtherapeutic levels in feeds. The studies are designed by FDA to ensure that antibiotic treatment of food-producing animals does not alter pathogen load or resistance pattern of pathogens. Two studies are generally performed: i) the salmonella shedding study, which addresses the effect of drug treatment on the excretion of salmonella in the feces of animals artificially infected with salmonella; and ii) the coliform resistance study, which monitors the effect of the drug on the resistance pattern of E. coli present in the endogenous fecal flora. After a retrospective study of the microbiological safety over past 20 yr, CVM of FDA is planning to revise some microbiological safety studies with focuses on: i) pathogen load, pathogen excretion and microorganism resistance pattern at the time of slaughter; and ii) susceptibility studies on products that have utility in human medicine. Key words: Animal drug, food safety, antibiotic

At birth, 98 piglets were either completely dried with paper towels, or moved under a heat lamp, or left untouched. The three treatments were randomly assigned, within birth order trios, to 11 litters of pigs. Sixty percent of all piglets contacted the udder within 10 min and 91% had nursed within 70 min. Treatment or birth order did not affect the mean time from birth to first udder contact (20 min; SEM 3.5) or the mean time from birth to first suckle (40 min; SEM 4.8). Average daily gain to 24 h or 21 d was not significantly affected by treatment. Mortality to 3 d was 6% for the towel-dried group, 0% for the pigs placed under the heat lamp and 21% for the untouched group. We conclude that drying or warming at birth did not affect suckling success of active piglets, but there was an indication that survival was improved. Key words Newborn, piglet, drying, warming, suckling, survival

This paper examines the spread and influence of a 1;29 Robertsonian translocation in a purebred beef herd. An entire herd of 94 Charolais cattle has been karyotyped since discovery of a 1;29 Robertsonian translocation in two yearling bulls entered in the Saskatoon R.O.P. bull test station in 1987. The translocation was inherited through their maternal grandfather. Approximately 46% (43) of the 94 cattle karyotyped possessed this translocation, including one cow which had two copies (58, XX, tt). The test herd consisted of 59 cows, 4 bulls, and 31 calves with 27, 2, and 14 animals affected respectively. In addition one cow with an additional X chromosome was detected (61, XXX). The overall fertility of this herd had been low but alterations in management practices lessened the negative impact. Prolonged bull exposure, first exposure of females at 2 y of age, and continued surveillance of cows returning to heat followed by rebreeding ensured that most cows did produce calves in most years. However, although such practices reduced the culling rate, they maintained the translocation carrier cows in the herd. Key words: Beef cattle, translocation, embryonic loss, subfertility

Five experiments involving 90 newborn colostrum-deprived pigs were conducted in an attempt to develop a method of rearing applicable in a non-isolated environment. Immune globulins, prepared by ammonium sulphate fractionation of porcine serum, and comprised of a mixture of approximately 75 per cent γ-globulin and 25 per cent β-globulin, were administered orally or parenterally in varying amounts and for varying periods of time. In two experiments porcine albumin, in serum or in a semi-purified solution, was provided in addition to the immune globulins. The distribution of serum proteins in the pigs was studied from birth to 12 weeks of age by paper strip electrophoresis.Parenteral administration of immune globulins did not provide an effective passive immunity, nor did oral administration for 1 day post-partum. A marked improvement in survival occurred when oral administration was continued for 5 days, and it was further found that this treatment provided apparently complete protection against infection during the 5-day period of administration. Albumin appeared to further improve survival.These results, together with the relatively poor survival obtained with positive control pigs (nursed 24 hours) suggested a continuing need for a supply of immune globulins in the lumen of the intestinal tract. Presumably these globulins were active as coproantibodies.The percentage survival in pigs weighing 3 pounds or more at birth was substantially higher than in smaller pigs. Mortality in these experiments was usually attributable to colibacillosis.Serum immune globulin levels at 2 days of age in the artificially reared pigs were elevated in proportion to the amount of globulins given. The effect of albumin was to create a serum protein pattern resembling that of suckled pigs. A marked decline in γ-globulin levels from 2 days to approximately 6 weeks was observed.

This is the second in a series of reports on the growth, feed intake and digestibility responses of growing swine (50 to 110 pounds) involved in a 2 × 2 × 2 × 2 factorial test of the effects of wheat bran, pelleting, antibiotics and type of protein in the ration. Discussion in this paper was restricted to those factors affecting the responses to the inclusion of wheat bran.With approximately isocaloric diets the inclusion of 10 per cent bran resulted in a general increase of 6 per cent in feed intake (P =

A swine feeding trial, of 2 × 2 × 2 × 2 factorial design, involving 64 pigs (32 gilts and 32 barrows) weighing initially 50 ± 2 pounds and fed to a final weight of 110 ± 2 pounds was carried out. The dietary variables were meal vs. pellets, 0 vs. 10 per cent wheat bran, mixed animal-plant vs. all-plant origin protein supplement and 0 vs. 33 p.p.m. of an antibiotic mixture (penicillin, streptomycin and chlortetracycline). Weight gains and feed intakes were recorded bi-weekly and a Cr2O3-marker digestion trial was imposed on 32 pigs during the feeding test.The results revealed distinct interrelationships among all four experimental variables that prevailed through to the highest order statistical interaction. Consequently discussion in this paper was restricted to those factors affecting the responses to pelleting.On the whole there was no advantage due to pelleting. However, in the absence of bran and antibiotics, and particularly when no animal protein was involved, pigs fed pelleted feed gained faster and had better feed efficiency. Pelleting was found to increase dry matter and energy digestibility when no bran or antibiotics were included in the diet. Conversely, the inclusion of either bran or antibiotics was as effective as pelleting. It is postulated that bran and antibiotics were effective by reason of their effects on the physical nature of the ingesta and on the microbial population of the gastrointestinal tract.

This paper describes the separation of rumen mucosa cells by pretrypsinization with 0.1% trypsin elusion solution composed of 2% sodium citrate, 2% EDTA-Na, 0.001% Tween 80 and 0.01% polybrene in 0.9% sodium chloride, pH 7.2. In the use of the cells separated following trypsin-EDTA treatment, three culture cases are described. Key words: Cell culture, rumen mucosa, bovine