Date of Completion

5-5-2018

Embargo Period

10-27-2018

Advisors

Kristen E. Govoni, Steven A. Zinn, Sarah A. Reed, Maria L. Hoffman

Field of Study

Animal Science

Degree

Master of Science

Open Access

Open Access

Abstract

Maternal programming can have numerous detrimental effects on offspring development, growth, and health. To improve livestock production efficiency, it is necessary to determine the mechanisms that can result in reduced growth, health, and product quality. We hypothesized that 1) restricted- and over-feeding during gestation would inhibit offspring muscle development, and 2) high maternal milk production would affect factors involved in offspring growth and immunity. To investigate the effects of poor maternal nutrition on offspring muscle development and growth, pregnant Western White-faced ewes (n = 82) were randomly assigned to one of three diets at day 30 of gestation through parturition; a control- (100% NRC requirements; CON), restricted- (60% NRC; RES), or over-fed (140%; OVER) diet. At day 45, 90, and 135 of gestation and within 24 hours of birth, ewes and fetuses were euthanized for collection of offspring longissimus dorsi, semitendinosus, and triceps brachii (n = 10 to 15 fetuses per treatment per time point). Muscle sections were immunostained with Pax7 antibody and data were analyzed using PROC MIXED in SAS. An interaction of maternal diet by time point was observed in the semitendinosus (ST) and triceps brachii (TB), where Pax7(+) cells were decreased in RES offspring at day 45, 90, and 135 in the ST (P ≤ 0.02) and day 90 in the TB (P ≤ 0.002). Within OVER offspring, Pax7(+) cells were decreased at day 90 in the ST (P ≤ 0.02) and day 45 and 90 in the TB (P ≤ 0.04). No effect of maternal diet by time point was observed in the LD (P = 0.57). An interaction of maternal diet by litter size was also observed, where singletons and twins had reduced Pax7(+) cells in the ST and TB (P ≤ 0.02) but triplets had an increased percentage of Pax7(+) cells in the LD (P ≤ 0.04). In conclusion, maternal restricted- and over-feeding negatively affects prenatal muscle development over time but these effects are muscle specific. To investigate the effects of maternal milk production during gestation on calf growth and immunity, morphometric measurements and blood samples were obtained from dairy calves born to high (average lactation of 14,865 kg of milk; n = 17) or low (average lactation of 10,069 kg of milk; n = 18) milk producing cows within 24 hours of birth. Offspring will be referred to as HIGH or LOW, respectively. Blood samples were analyzed to determine concentrations of insulin, glucose, haptoglobin, interferon gamma, and other biochemical factors relating to growth and immunity. An effect of maternal lactation by gender was observed for skull width (P = 0.09), nose-occipital length (P = 0.03), glucose (P = 0.05), direct bilirubin (P = 0.07), calcium (P = 0.08), and magnesium (P = 0.07). Additionally, an effect of lactation was observed for total protein and globulin (P ≤ 0.01). No effect of lactation by gender, lactation, or gender was observed for insulin (P = 0.53), serum IgG (P = 0.23), colostrum IgG (P =32), or haptoglobin (P = 0.24). In conclusion, maternal lactation status can affect several factors relating to offspring growth and health. Future studies are required to further assess the effects of maternal programming on offspring development, growth, and health to improve current livestock production.

Major Advisor

Kristen E. Govoni

Available for download on Saturday, October 27, 2018

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