Programming effects of maternal and gestational obesity on offspring metabolism and metabolic inflammation.

With the increasing prevalence of obesity in women of reproductive age there is a need to understand the ramifications of this on offspring. The purpose of this study is to investigate the programming effects of maternal obesity during preconception and the preconception/gestational period on adiposity and adipose tissue inflammation in offspring using an animal model. Adult female C57Bl/6J mice were assigned either normal diet, high fat diet (HFD) prior to pregnancy, or HFD prior to and through pregnancy. Some offspring were maintained on normal diet while others started HFD later in life. Offspring were assessed for body composition and metabolic responses. Lipid storing tissues were evaluated for expansion and inflammation. Male offspring from the preconception group had the greatest weight gain, most subcutaneous adipose tissue, and largest liver mass when introduced to postnatal HFD. Male offspring of the preconception/gestation group had worsened glucose tolerance and an increase in resident (CD11c-) adipose tissue macrophages (ATMs) when exposed to postnatal HFD. Female offspring had no significant difference in any parameter between the diet treatment groups. In conclusion, this study demonstrates that prenatal and pregnancy windows have independent programming effects on offspring. Preconception exposure affects body composition and adiposity while gestation exposure affects metabolism and tissue immune cell phenotypes.

Influence of forage source and forage inclusion level on growth performance, feeding behavior, and carcass characteristics in finishing steers.

Two experiments were conducted to determine the effects of forage source (Exp. 1) and forage inclusion level (Exp. 2) in finishing diets on growth performance and feeding behavior. In Exp. 1, sixty-four steers (394 ± 3.6 kg BW) were allotted by BW to 3 pens. Within each pen, steers were assigned randomly to 1 of 4 dietary treatments containing different forage sources: 1) alfalfa hay, 2) corn silage, 3) wheat straw, and 4) corn stover. Alfalfa hay was provided at 10% of the diet DM and the other forage sources were offered to provide the same percentage of NDF from forage. In Exp. 2, forty-four steers (451 ± 4.6 kg BW) were used in a completely randomized design and were fed dry-rolled corn-based diets containing a mixture of hay and corn silage as the forage source at 5%, 10%, 15%, or 20% forage (DM basis). Intake and feeding behavior traits were calculated from data generated by the Insentec feeding system. In Exp. 1, final BW, ADG, and G:F did not differ between treatments. Dry matter intake and feeding behavior traits responded differently depending on week (interaction ≤ 0.04) of the experiment with DMI generally greater in steers fed alfalfa or corn silage early in the experiment and time per meal generally greater and eating rate slower in steers fed diets containing wheat straw or corn stover. In Exp. 2, ADG and G:F decreased linearly ( < 0.001) with increasing forage inclusion. Quadratic effects ( ≤ 0.002) were observed for eating time (per visit, meal, and d) and DMI (per visit, meal, and min) with eating time greatest in the 10% forage treatment and DMI the least in the 20% forage treatment. Dry matter intake per d responded differently depending on week (interaction = 0.01) with some weeks exhibiting linear and other quadratic effects that were primarily the result of the largest decrease in DMI in the 20% forage inclusion treatment. These data indicate that growth performance was not influenced by forage source, when fed at a similar NDF inclusion level, but was negatively impacted by increasing forage inclusion in high-concentrate finishing diets. However, both forage source and inclusion level impacted feeding behavior as cattle consuming bulkier forages (wheat straw or corn stover) or at greater inclusion levels typically had a slower eating rate and took longer to consume a meal. Additionally, DMI may decrease at greater forage inclusion levels (> 15%).

Influence of dry-rolled corn processing and increasing dried corn distillers grains plus solubles inclusion for finishing cattle on growth performance and feeding behavior.

Sixty-four yearling steers (345 ± 4.2 kg BW) were used to study the effects of degree of dry-rolled corn processing and corn dried distillers grains plus solubles (DDGS) inclusion on feeding and ruminating behavior, G:F, and carcass characteristics. Steers were assigned randomly to 1 of 4 experimental treatments (n = 16 per treatment): 1) coarse-rolled (2.68 mm) corn and 20% DDGS, 2) coarse-rolled corn and 40% DDGS, 3) fine-rolled (1.46 mm) corn and 20% DDGS, and 4) fine-rolled corn and 40% DDGS. Final BW and ADG were not affected by corn processing or DDGS. Dry matter intake (kg/d and % of BW) decreased (P < 0.001) and G:F increased (P < 0.001) with increasing inclusion of DDGS. Meal number increased (P ≤ 0.05) and meal size decreased (P < 0.001) with finer dry-roll corn processing and with increasing inclusion of DDGS. Drinking time decreased (P = 0.03) with finer dry-rolled corn processing and tended to increase (P = 0.06) with increased inclusion of DDGS. Rumination time while standing decreased (P = 0.03) with increased inclusion of DDGS. Increasing inclusion of DDGS from 20 to 40% decreased intake, increased G:F, and altered feeding behavior of finishing steers consuming a 90% concentrate diet without affecting carcass quality. Increasing the degree of dry-roll corn processing did not impact growth performance and did not interact with increasing inclusion of DDGS in finishing diets.