Winter grazing system and supplementation during late gestation influence performance of beef cows and steer progeny1

Abstract

A 2 × 2 factorial study evaluated effects of cow wintering system and last trimester CP supplementation on performance of beef cows and steer progeny over a 3-yr period. Pregnant composite cows (Red Angus × Simmental) grazed winter range (WR; n = 4/yr) or corn residue (CR; n = 4/yr) during winter and within grazing treatment received 0.45 kg/d (DM) 28% CP cubes (PS; n = 4/yr) or no supplement (NS; n = 4/yr). Offspring steer calves entered the feedlot 14 d postweaning and were slaughtered 222 d later. Precalving BW was greater (P = 0.02) for PS than NS cows grazing WR, whereas precalving BCS was greater (P < 0.001) for cows grazing CR compared with WR. Calf birth BW was greater (P = 0.02) for CR than WR and tended to be greater (P = 0.11) for PS than NS cows. Prebreeding BW and BCS were greater (P ≤ 0.001) for CR than WR cows and PS than NS (P = 0.006) cows. At weaning, CR cows were heavier (P < 0.001) than WR cows but had similar BCS (P = 0.74). Cow weaning BW and BCS were not affected (P > 0.32) by PS.Calf weaning BW was less (P = 0.01) for calves from NS cows grazing WR compared with all other treatments. Pregnancy rate was unaffected by treatment (P > 0.39). Steer ADG, 12th-rib fat, yield grade, and LM area (P > 0.10) were similar among all treatments. However, final BW and HCW (P = 0.02) were greater for steers from PS-WR than NS-WR cows. Compared with steers from NS cows, steers from PS cows had greater marbling scores (P = 0.004) and a greater (P = 0.04) proportion graded USDA Choice or greater. Protein supplementation of dams increased the value of calves at weaning (P = 0.03) and of steers at slaughter regardless of winter grazing treatment (P = 0.005). Calf birth and weaning BW were increased by grazing CR during the winter. Calf weaning BW was increased by PS of the dam if the dam grazed WR. Compared with steers from NS cows, steer progeny from PS cows had a greater quality grade with no (P = 0.26) effect on yield grade. These data support a late gestation dam nutrition effect on calf production via fetal programming.

Calving date and wintering system effects on cow and calf performance I: A systems approach to beef production in the Nebraska Sandhills

“…In agreement with the results of the present study, Larson et al (2009) reported similar calf performance from birth to weaning when cows were wintered on native Sandhills range or corn residue.…”

“…They showed cows wintered on corn residue had lower BW and BCS at weaning than cows wintered on pasture. However, Larson et al (2009) reported cows wintered on corn residue had greater BW at weaning than cows wintered on native Sandhills range even though BCS at weaning was not different. Also, Anderson et al (2005) and Larson et al (2009) showed no difference in pregnancy rates of cows a-c Within a row, means with unlike superscript letters differ (P < 0.05).…”

“…Therefore, differences in BW and BCS presumably were more a result of differences in energy supply from the forage relative to energy requirement of the cows during the production year. Energy status is an important factor affecting cow performance (Stalker et al, 2006;Larson et al, 2009). During peak lactation energy requirements are greater than at any other time.…”

Grazing intensity and soil depth effects on soil properties in alpine meadow pastures of Qilian Mountain in northwest China

“…spring-autumn pasture (SAP) are used ( Figure 1). The SAP tends to be utilized by graziers as a convenient hub for livestock to move to higher elevation in summer or lower altitude in winter (Helle & Aspi 1983;Larson et al 2008). The pastures studied are part of a total area of 5900 ha of pasture managed by a single commercial entity engaged in farming wapiti deer.…”

BEEF SPECIES SYMPOSIUM: An assessment of the 1996 Beef NRC: Metabolizable protein supply and demand and effectiveness of model performance prediction of beef females within extensive grazing systems1,2,3

“…Reported changes in birth weights in response to moderate, but not low or high, amounts of MP supplied by UIP may be indicative of developmental programming (i.e., in utero nutrient environments impact offspring performance) by gestational MP supply. Others (Stalker et al, 2006;Martin et al, 2007;Larson et al, 2009) have also reported developmental programming by protein supplementation during gestation. This area of developmental programming in response to MP supply coupled with potential metabolic effects of rumenprotected AA warrants further investigation.…”