Effects of Dam Age, Prepartum Nutrition and Duration of Labor on Productivity and Postpartum Reproduction in Beef Females

Abstract

Sixty-two, 2-yr-old heifers and 65 cows, 4 to 7 yr old, were assigned randomly at 60 d before the median predicted calving date to a factorially designed study. Main effects were: age of dam (heifer or cow), moderate (M) or high (H) precalving feed level (110 or 135% of National Research Council recommendation) and short (S) or prolonged (P) duration of Stage II of parturition. After calving, all dams were placed in the same range pastures and received supplemental hay and a grain-salt mix until adequate range forage was available to produce weight gains in the lactating dams. Dams were bred in a 45-d artificial insemination period. Calving difficulty scores and duration of labor (Stage II) were greater (both P less than .01) in heifers than in cows; calf birth weight (P less than .01), calf vigor at birth (P less than .05) and calf gains birth to weaning (P less than .01) were higher in cows. Effect of gestation feed level on precalving, calving and postpartum data were nonsignificant. Eighty-two percent of the S females were given obstetrical assistance and 15% of the P females required assistance at parturition (P less than .01). More S dams exhibited estrus by the beginning of the breeding season than P dams (91.4 vs 81.7%, P less than .10), and October pregnancy of S dams was higher than P dams (89.5 vs 75.6%, P less than .05). Interaction effects of dam X duration of Stage II were not significant, but short duration of labor had beneficial effects on postpartum reproduction in both dam age groups. Results of this study indicate prolonged labor may result in depressed subsequent reproduction in beef dams.

Effects of early- to mid-gestational undernutrition with or without protein supplementation on offspring growth, carcass characteristics, and adipocyte size in beef cattle1

“…Similar birth weights of calves in the present study are consistent with Long et al (2010b) and others (Doornbos et al, 1984;Goehring et al, 1989;Houghton et al, 1990) who showed that restriction of dietary energy before the last trimester of gestation did not influence birth weight or gestational length. Additionally, it has been reported that if postnatal nutrition is adequate, any effects of maternal diets during mid or late gestation on birth weights will not result in altered calf BW either before or at weaning (Hight, 1968;Freetly et al, 2000).…”

Effect of weaning date (normal vs. late) on performance of young and mature beef cows and their progeny in a fall calving system in the Southern Great Plains1

“…It appears that greater cow BW and BCS at calving led to increased calf preweaning BW gain. This is in contrast to previous reports that milk production or preweaning and 205-d adjusted weaning BW of calves are not influenced by cow body energy reserves, as indicated by BCS, when cows are in moderate body condition at the time of parturition (Doornbos et al, 1984;DeRouen et al, 1994;Spitzer et al, 1995;Ciccioli et al, 2003).…”

A Simultaneous Equations Model of the Cause-Effect Relationships Among Biological Variables: An Analysis Using Postpartum Beef Cows

“…That is, when variables other than those reported in Table 3 were included in the specification the estimated coefficients on those variables were not significantly different from zero, the estimated coefficients in Table 3 Doornbos et al (1984).…”

“…With OLS analysis and a broader categorization (age of dam X obstetrical assistance) an effect on PPI was not statistically discernible (Doornbos et al 1984 …”