Poor Maternal Diet During Gestation Alters Offspring Muscle Morphometrics, Collagen Gene Expression, and Meat Tenderness in Sheep

We hypothesized that maternal overfeeding and restricted feeding during gestation would alter the collagen content, muscle fiber cross-sectional area (CSA), and meat tenderness in offspring. Pregnant ewes were fed 100% (CON), 60% (RES), or 140% (OVER) of their requirements from day 30 of gestation until parturition. Male offspring were necropsied at 282 ± 1.8 days of age. Gene expression and CSA were quantified in the longissimus (LM) and semitendinosus (STN) muscles. The Warner-Bratzler shear force (WBSF) was quantified in LM. Data were analyzed by one-way ANOVA, with diet as a fixed effect. Differences were considered significant at <i>p</i> ≤ 0.05 or a tendency at <i>p</i> ≤ 0.10. Semitendinosus CSA was smaller in OVER and RES than CON rams (<i>p</i> = 0.02). Longissimus CSA was larger in RES than OVER and CON rams (<i>p</i> = 0.002). OVER LM had reduced WBSF compared with CON rams (<i>p</i> = 0.03). Myogenic genes <i>bone morphogenic protein 1</i> (BMP1) and <i>paired box 7</i> were greater in RES LM than OVER (<i>p</i> ≤ 0.02). Maternal diet altered the fibrogenic genes <i>fibronectin 1</i> (<i>p</i> = 0.07), <i>lysyl oxidase</i> (<i>p</i> = 0.07), and <i>collagen 1A1</i> (COL1A1; <i>p</i> = 0.08) in the LM and <i>COL1A1</i>, <i>COL3A1</i>, and <i>BMP1</i> (<i>p</i> ≤ 0.09) in the STN. Poor maternal diet during gestation alters muscle and meat characteristics that may impact meat quality.