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Full-Text Articles in Dairy Science
Effect Of Varying Rumen Degradable And Undegradable Protein On Milk Production And Nitrogen Efficiency In Lactating Dairy Cows Under Summer Conditions, Jeffrey D. Kaufman
Effect Of Varying Rumen Degradable And Undegradable Protein On Milk Production And Nitrogen Efficiency In Lactating Dairy Cows Under Summer Conditions, Jeffrey D. Kaufman
Masters Theses
The objective is to determine the effect of reducing nitrogen input through feeding low rumen degradable protein (RDP) and rumen undegradable protein (RUP) proportions on milk production, nitrogen efficiency and metabolism in heat-stressed cows. Forty-eight mid-lactating, Holstein cows were assigned to treatments using a randomized block design in a 2x2 factorial arrangement of treatments (n = 12/treatment). Treatments included two levels of RDP (10 and 8%) and two levels of RUP (8 and 6%). From d 1 to 21, a common diet (10% RDP-8% RUP) was fed to cows followed with their respective treatment diets fed from d 22 to …
The Effect Of Heat Stress And Essential Amino Acids On Production And Metabolism Of Lactating Dairy Cattle, Kimberly Rose Kassube
The Effect Of Heat Stress And Essential Amino Acids On Production And Metabolism Of Lactating Dairy Cattle, Kimberly Rose Kassube
Masters Theses
Heat stress (HS) causes decreases in production of lactating cattle that is only partially explained by decreases in intake. Evidence suggests that changes in energy and protein metabolism occur to cope with the impact of HS. The objective of this thesis was to determine if the effect of jugular infusion of essential amino acids (AA) ameliorated the negative effects of HS in milk production and metabolism. Twelve multiparous lactating Holstein cows were used in a crossover design to evaluate the effect of thermoneutral (THN) and HS environments along with the absence (CTL) …
Impact Of Matrix Metallopeptidase-9 Supplementation During In Vitro Maturation Of Bovine Oocytes, Megan Rene Goodwin
Impact Of Matrix Metallopeptidase-9 Supplementation During In Vitro Maturation Of Bovine Oocytes, Megan Rene Goodwin
Masters Theses
Heat-induced decreases in bovine blastocyst development have been related to reductions in latent matrix metallopeptidase-9 (proMMP9) production from maturing cumulus-oocyte complexes. Elevated intrafollicular proMMP9 levels at the time of oocyte retrieval have been positively related to pregnancy following human IVF. Thus, we hypothesized that heat-induced reductions in proMMP9 levels during oocyte maturation may be responsible for decreased blastocyst development. As a first step towards testing this hypothesis, bovine cumulus-oocyte complexes were matured at 38.5°C for 24 h with 0 or 300 ng/mL recombinant human proMMP9 (rhMMP9) added at 0 h of in vitro maturation (hIVM). No differences were found in …
Assessing Mitochondrial Activity In Embryos From Heat-Stressed Ova, Kimberly Ann Nagle
Assessing Mitochondrial Activity In Embryos From Heat-Stressed Ova, Kimberly Ann Nagle
Masters Theses
Elevated ambient temperatures negatively impacts pregnancy rates in agriculturally important females. An oocyte undergoing meiotic maturation exposed to a physiologically-relevant heat stress results in alterations of developmentally important processes and reportedly decreases subsequent developmental potential after fertilization. To address problems of reduced competence after exposure to heat stress for the first 12 h of meiotic maturation (hIVM), Payton (2009) assessed the transcriptome profiles of oocytes and associated cumulus cells by microarray analysis and reported heat-induced perturbations at the molecular level in the oocyte. Specifically, 20 transcripts involved in mitochondrial function exhibited alterations in relative abundance of heat-stressed oocytes …
The Challenges Of Making A Blastocyst-Stage Embryo: Impact Of Heat Stress & Technical Factors Associated With Ivp Procedures, Estanislao Peixoto
The Challenges Of Making A Blastocyst-Stage Embryo: Impact Of Heat Stress & Technical Factors Associated With Ivp Procedures, Estanislao Peixoto
Masters Theses
It was hypothesized that technical factors associated with in vitro production (IVP) of embryos may influence rate of blastocyst development of oocytes matured at 38.5 or 41.0 C. To test this hypothesis, a retrospective meta-analysis was performed. Simple linear regression was performed to analyze continuous variables and ANOVA for categorical variables. Interactions among factors and maturation temperature on blastocyst development were analyzed using dummy regression for continuous variables, and using a factorial treatment design and ANOVA for categorical variables. Month of collection was the only variable that impacted responsiveness of ova to heat stress. Independent of maturation temperature, variables that …