Effect of dried corn distillers grains plus solubles compared with soybean hulls, in late gestation heifer diets, on animal and reproductive performance1

Abstract

Dried distillers grains plus solubles (DDGS) contain fat and rumen undegradable intake protein, both of which have been shown to increase reproductive performance in heifers. The mechanisms leading to enhanced reproduction have not been fully defined. The objectives of this research were to evaluate effects of DDGS in late gestation heifer diets on animal and reproductive performance and on blood plasma concentrations of GH, IGF-I, and NEFA. Over 2 yr, 201 heifers were randomly allotted to 1 of 2 diets, which were similar in energy and adequate in rumen degradable intake protein and were fed from d 190 of gestation through calving. Diets were grass hay with DDGS or soybean hulls (SBH) and a supplement. Cow BW and BCS were measured from the beginning of treatment through weaning. Blood samples were collected prepartum on d 71 and 69 of the feeding period and weekly after calving for 4 and 6 wk (d 84 to 105 and d 76 to 111 relative to the feeding period) during yr 1 and 2, respectively. No treatment x year interactions were detected for any of the performance, hormonal, or reproductive dependent variables. Both treatments caused positive BW changes over the feeding period, but DDGS heifers had a greater (P < 0.01) positive BW change compared with SBH heifers. Initial and final BCS and BCS change were similar (P >/= 0.26) between DDGS and SBH treatments. Treatment did not influence (P >/= 0.12) BW or BCS change during the postpartum period. Calving ease, calf vigor, and calf birth weight, weaning weight, and ADG (birth to weaning) were similar (P >/= 0.41) between treatments. The proportion of cows that had initiated estrous cycles (P = 0.46) and the pregnancy distribution (P >/= 0.21) were similar between treatments. However, a greater (P = 0.058) percentage of DDGS cows became pregnant compared with SBH cows (94 and 84%). In both years, there were no effects of treatment (P >/= 0.17) or treatment x time (P >/= 0.52), but time influenced (P </= 0.05) the concentrations of GH, IGF-I, and NEFA. Concentrations of GH were greater (P </= 0.05) at calving and decreased through d 4 after calving. The IGF-I concentrations were greater (P < 0.01) around calving and decreased (P < 0.05) through d 8 or 6 (yr 1 or 2) and remained similar (P > 0.10) for the duration of the sampling period. Concentrations of NEFA increased from calving through d 8 and gradually declined through d 20. Prepartum diets containing DDGS, a source of fat and UIP, benefited pregnancy rates in well-maintained, primiparous beef heifers.

Feeding dried distillers grains with solubles to lactating beef cows: impact of excess protein and fat on cow performance, milk production and pre-weaning progeny growth

“…Also, fat concentrations were elevated in the DDGS diets in the present experiment and a greater percentage of UFAs in DDGS have been reported to bypass ruminal biohydrogenation compared with control diets (Vander Pol et al, 2009). It has been proposed that fat supplementation, specifically PUFAs (Mattos et al, 2000), or a combination of both fat and CP (Engel et al, 2008;Gunn et al, 2014) improve reproductive performance. The specific nutrient and the mechanism by which fat, PUFAs, protein, or their combination increase TAI conception rates remains to be elucidated.…”

“…Studies with heifers have reported a decrease in postpartum anestrous when feeding 40% to 50% DDGS during late gestation (Engel et al, 2008) or when feeding 43% DDGS during late gestation and early lactation (Gunn et al, 2014). Pregnancy rates have improved for some studies when DDGS was fed during late gestation (Engel et al, 2008), but TAI and overall pregnancy rates have not been altered in other studies when DDGS was fed during late gestation (Radunz et al, 2010) or during early lactation (Shike et al, 2009). Gunn et al (2014) observed that DDGS increased follicle growth rates, increased dominant follicle diameters and decreased the anestrous period compared with control fed cows.…”

“…However, when excess protein was fed in combination with additional dietary fat during the last 100 days of gestation and first 100 days of lactation in beef cows, as is the case when DDGS is fed, altered energy partitioning occurs in the cow and reproductive performance was improved (Gunn et al, 2014). It has been proposed that fat supplementation (Santos et al, 2008); fatty acid composition, specifically polyunsaturated fatty acids (PUFAs; Mattos et al, 2000); and type of protein, specifically rumen protein (RUP; Martin et al, 2007), or a combination of both fat and protein (Engel et al, 2008) improve reproductive performance. Gunn et al (2014) also reported increased dystocia rates in cows fed large amounts of DDGS during gestation and lactation.…”

Effects of preovulatory estradiol on embryo survival and pregnancy establishment in beef cows

“…Samples were placed at 4 • C for approximately 24 h. Samples were centrifuged at 1200 × g for 25 min at 4 • C and serum was collected and stored at −20 • C until radioimmunoassays were performed. Radioimmunoassay (RIA) was performed on serum samples to measure progesterone concentrations using the methods described by Engel et al (2008). Inter-and intra-assay CV were 13.67% and 4.52%, respectively and assay sensitivity was 0.4 ng/mL.…”

The effects of vaccination on serum hormone concentrations and conception rates in synchronized naive beef heifers

“…Plasma was frozen and all samples were subsequently analyzed for concentrations of P4 by radioimmunoassay as described [18]. Intra-and interassay coefficients of variation for P4 assays were 2.3% and 6.4%, respectively, and assay sensitivity was 0.4 ng/mL.…”