Author

Ousama AlZahal

University of Guelph, Canada

6 articles in our journals

Articles where this person is an author, newest first. People are matched by their name as printed (no ORCID iD is recorded for them), not by name alone; search the name as text to find namesakes too.

Research ArticleOpen accessDo Cows Under Subacute Ruminal Acidosis (SARA) Attempt to Self-Medicate?Erin Hendriksen, Ousama AlZahal, Tom C. Wright et al.The objective of this study was to examine feed-sorting behavior of dairy cows in response to a grain challenge that leads to Subacute Ruminal Acidosis (SARA). Sixteen multiparous, rumen-cannulated lactating Holstein cows were used. During the first 49 days of the experiment, all cows received a High-Forage diet (HF; 77:23, F: C; NFC=35). Cows were then transitioned to a High-Grain … …American Journal of Animal and Veterinary Sciences, Vol. 10, Issue 3 · 2 Sep 2015 · 7,571 accessesView PDF Cite

Research ArticleOpen accessChanges in the Rumen Papillae During the Periparturient Transition in Holstein Dairy Cows are Accompanied by Changes in Abundance of Proteins Involved in Intracellular pH Regulation, But not SCFA TransportAnne Hermen Laarman, Adam Kleinberg, Michael Alexander Steele et al.The objective of this study was to examine changes in SCFA transport capacity in the rumen epithelium during the parturition transition period. Twelve pregnant, cannulated primiparous and multiparous cows were fed a standard Total Mixed Ration (TMR) for the duration of the dry period; after calving, all cows were switched to an early lactation TMR. Rumen pH, fluid and biopsies … …American Journal of Animal and Veterinary Sciences, Vol. 10, Issue 1 · 31 Mar 2015 · 7,546 accessesView PDF Cite

Research ArticleOpen accessTRANSCRIPTOMIC CHANGES IN RUMINAL TISSUE INDUCED BY THE PERIPARTURIENT TRANSITION IN DAIRY COWSLouis Dionissopoulos, Ousama AlZahal, Michael Alexander Steele et al.To understand how the capacity for fat metabolism (uptake, synthesis, modification) changes in rumen epithelia immediately before and after onset of lactation in dairy cows, rumen fluid Short Chain Fatty Acid (SCFA) concentrations and mRNA expression profiles of rumen epithelia was determined in twelve Holstein dairy cows at three weeks prior to calving (wk -3, n = 12), one week … …American Journal of Animal and Veterinary Sciences, Vol. 9, Issue 1 · 13 Jan 2014 · 7,501 accessesView PDF Cite

Research ArticleOpen accessButyrate Supplementation Affects Mrna Abundance of Genes Involved in Glycolysis, Oxidative Phosphorylation and Lipogenesis in the Rumen Epithelium of Holstein Dairy CowsAnne Hermen Laarman, Louis Dionissopoulos, Ousama AlZahal et al.Energy availability in epithelial cells is a crucial link for maintaining epithelial barrier integrity; energy depletion is linked to impaired barrier function in several epithelia. This study aimed to elucidate the effects of exogenous butyrate on mRNA abundance of genes indirectly involved in rumen epithelial barrier integrity. Sixteen mid-lactation Holstein cows fed a total mixed ration received a concentrate mix … …American Journal of Animal and Veterinary Sciences, Vol. 8, Issue 4 · 27 Nov 2013 · 7,519 accessesView PDF Cite

Research ArticleOpen accessButyrate and Subacute Ruminal Acidosis Affect Abundance of Membrane Proteins Involved with Proton and Short Chain Fatty Acid Transport in the Rumen Epithelium of Dairy CowsAnne Hermen Laarman, Louis Dionissopoulos, Ousama AlZahal et al.The objective of this study was to elucidate the effects of butyrate on the Short Chain Fatty Acids (SCFA) membrane transport proteins and proton membrane transport proteins in the rumen epithelium. Sixteen mid-lactation cows were fed a 44% Non-Fibre Carbohydrate (NFC) diet and divided into a control treatment and a butyrate treatment. For 7 days, the cows on the control … …American Journal of Animal and Veterinary Sciences, Vol. 8, Issue 4 · 27 Nov 2013 · 7,475 accessesView PDF Cite

Research ArticleOpen accessButyrate-Mediated Genomic Changes Involved in Non-Specific Host Defenses, Matrix Remodeling and the Immune Response in the Rumen Epithelium of Cows Afflicted with Subacute Ruminal AcidosisLouis Dionissopoulos, Anne Hermen Laarman, Ousama AlZahal et al.Subacute Ruminal Acidosis (SARA) is a disorder in cattle which can lead to chronic inflammation in the rumen epithelium, known as rumenitis. Butyrate has been shown to attenuate some of the detrimental effects of inflammatory gastroenteral disorders but the molecular mechanisms mediated by butyrate have not been defined. The objective of this study was to define the inflammatory-related genomic changes … …American Journal of Animal and Veterinary Sciences, Vol. 8, Issue 1 · 10 Jan 2013 · 8,059 accessesView PDF Cite