Visceral adipose tissue mass in nonlactating dairy cows fed diets differing in energy density1

Abstract

Our objective was to determine dietary energy effects on feed intake, internal fat deposition, body condition score (BCS), visceral organ mass, and blood analytes in Holstein cows. Eighteen nonpregnant, nonlactating cows (BCS = 3.04 ± 0.25) were blocked based on initial BCS and were randomly assigned within each block to 2 treatments. Treatments were either high energy [HE; net energy for lactation (NEL)=1.62 Mcal/kg] or low energy (LE; NEL = 1.35 Mcal/kg) diets fed as total mixed rations for 8 wk. The LE diet consisted of 81.7% forage, including 40.5% wheat straw and 28.3% corn silage, whereas the HE diet contained 73.8% forage with no straw and 49.9% corn silage (dry matter basis). Cows were fed for ad libitum intake once daily at 0800 h. Feed intake was recorded daily, blood was sampled at wk 1, 4, and 7, and BCS was assigned at wk 1, 4, and 7. Cows were killed following the 8-wk period, and visceral organs, mammary gland, and internal adipose tissues were weighed and sampled. The HE group had greater dry matter intake (15.9 vs. 11.2 ± 0.5 kg/d) and energy intakes than cows fed LE, but neutral detergent fiber intake did not differ (5.8 vs. 5.6 ± 0.25 kg/d for HE and LE). Final body weight was greater for cows fed HE (807 vs. 750 kg), but BCS did not differ between groups (3.52 vs. 3.47 for HE and LE). Omental (26.8 vs. 15.2 ± 1.6 kg/d), mesenteric (21.5 vs. 11.2 ± 1.9 kg), and perirenal (8.9 vs. 5.4 ± 0.9 kg) adipose tissue masses were larger in HE cows than in LE cows. Although subcutaneous adipose mass was not measured, carcass weight (including hide and subcutaneous fat) did not differ between HE (511 kg) and LE (496 kg). Liver weight tended to be greater for cows fed HE, but weights of gastrointestinal tract, heart, and kidney did not differ. Serum insulin tended to be greater and the glucose to insulin ratio was lower for cows fed HE. Serum concentrations of β-hydroxybutyrate and cholesterol were greater for HE cows than for LE cows but concentrations of glucose, nonesterified fatty acids, total protein, and albumin did not differ. Final BCS was correlated with masses of omental (r = 0.57), mesenteric (r = 0.59), and perirenal (r = 0.72) adipose tissue, but mesenteric adipose mass increased more as BCS increased for cows fed HE. The similar final BCS between HE and LE cows demonstrates that BCS may lack sensitivity to detect differences in visceral fat deposition that might increase risk for peripartal diseases and disorders.

Analysis of daily body weight of dairy cows in early lactation and associations withproductive and reproductive performance

“…Cows that kept their BCS after calving showed a pregnancy rate of 41.6% against only 28.9% for those losing over 1 BCS point (scale of 1 to 5). Nevertheless, as shown by Drackley et al (2014), BCS may be the same between animals with high and low BW, which can confuse the interpretation.…”

“…The dairy industry had traditionally adopted body condition score (BCS) to evaluate BW loss in early lactation (Wildman et al, 1982). But, more recently, Drackley et al (2014) demonstrated that BCS may lack sensitivity to detect differences in visceral fat deposition that might increase risk for peripartal diseases and disorders.…”

Effects of day of gestation and feeding regimen in Holstein × Gyr cows: II. Maternal and fetal visceral organ mass

“…Few studies (He et al, 2013;Drackley et al, 2014) have been conducted to evaluate the effects of FR on maternal and fetal organ mass in dairy cows. Some studies have demonstrated that underfeeding during gestation can cause intrauterine growth restriction, which results in impaired development and potential long-term consequences (He et al, 2013).…”

Prepartum and postpartum nutritional management to optimize fertility in high-yielding dairy cows in confined TMR systems

“…Because energy that cows consume in excess of their requirements must either be dissipated as heat or stored as fat, we speculated that the excess is accumulated preferentially in internal adipose tissue depots in some cows. Moderate over-consumption of energy by non-lactating cows for 57 days led to greater deposition of fat in abdominal adipose tissues (omental, mesenteric, and perirenal) than in cows fed a high-bulk diet to control energy intake to near requirements (Drackley et al, 2014). The NEFA and signaling molecules released by visceral adipose tissues travel directly to the liver, which may cause fatty liver, subclinical ketosis and secondary problems with liver function.…”