Relationships among performance, residual feed intake, and product quality of progeny from Red Angus sires divergent for maintenance energy EPD1

Abstract

Energy expenditure is a physiological process that may be closely associated with residual feed intake (RFI). The maintenance energy (ME(M)) EPD was developed by the Red Angus Association of America (RAAA) and is used as an indicator of energy expenditure. The objectives of this study were to evaluate and quantify the following relationships using progeny of Red Angus (RA) sires divergent for ME(M) EPD: 1) postweaning RFI and finishing phase feed efficiency (FE), 2) postweaning RFI and end-product quality, and 3) postweaning RFI and sire ME(M) EPD. A total of 12 RA sires divergent for ME(M) EPD were chosen using the RAAA-generated ME(M) EPD values and were partitioned into 2 groups: high ME(M) EPD (≥4 Mcal/mo) and low ME(M) EPD (<4 Mcal/mo), based on the breed average of 4 Mcal/mo. Commercial crossbred cows were inseminated to produce 3 cohorts of progeny, which were tested for postweaning RFI (cohorts 1, 2, and 3) and finishing phase FE (cohorts 1 and 3). Results indicate that postweaning RFI and finishing phase FE of steer progeny tended to be positively correlated (r = 0.38; P = 0.06) in cohort 1 and were positively correlated (r = 0.50; P = 0.001) in cohort 3. In addition, postweaning RFI was not phenotypically correlated (P > 0.05) with any carcass traits or end-product quality measurements. Sire ME(M) EPD was phenotypically correlated (P < 0.05) with carcass traits in cohort 1 (HCW, LM area, KPH, fat thickness, and yield grade) and cohort 2 (KPH and fat thickness). Since variation in measured LM area was not explained by the genetic potential of rib eye area EPD, and therefore, the observed correlation between sire ME(M) EPD and measured LM area may suggest an association between ME(M) EPD and LM area. A correlation (r = 0.24; P = 0.02) was observed between postweaning RFI and ultrasound intramuscular fat percentage in cohort 2 but was not detected in cohorts 1 or 3. In addition, no phenotypic relationship was observed (P > 0.05) between progeny postweaning RFI and sire ME(M) EPD. Therefore, results suggest 1) RFI measured during the postweaning growth phase is indicative of FE status in the finishing phase, 2) neither RFI nor sire ME(M) EPD negatively affected carcass or end-product quality, and 3) RFI and sire ME(M) EPD are not phenotypically associated.

Meat and sensory quality of major muscles from Angus, Charolais, and Angus crossbred steers with high and low residual feed intake

“…Muscle pH and temperatures in this study were not measured during the early postmortem period, and no significant difference between RFI groups was observed for muscle temperature and pH at 72 h post mortem for all four muscles. In fact, selection for RFI did not affect the chemical composition of the four muscles from the different genetic groups, which is consistent with previous studies (Baker et al 2006;Ahola et al 2011;Welch et al 2012;Zorzi et al 2013;Nascimento et al 2016). Ahola et al (2011) found no significant difference in water and protein percentages, cooking loss, and juiciness across different RFI Angus steers, and Baker et al (2006) reported a tendency (not statistically significant) for protein and moisture of longissimus dorsi of Angus steers to be affected by RFI selection.…”

Growth performance, feed digestibility, body composition, and feeding behavior of high– and low–residual feed intake fat-tailed lambs under moderate feed restriction1

“…Research efforts for years indicate that RFI is a powerful selection tool for improving feed efficiency and decreasing feed costs, especially in beef cattle (Herd et al, 2003;Arthur and Herd, 2008;Hoque and Suzuki, 2009). Because RFI is defined as the difference between actual feed intake and expected feed intake, most of these studies have been conducted on free-access feeding of cattle (Meyer et al, 2008;Welch et al, 2012) or sheep (Snowder and Van Vleck, 2003) using medium-to highenergy diets. However, it is important to know whether the animals that were efficient or inefficient on a feeding regime are also efficient or inefficient on other feeding conditions such as programmed or restricted feeding regimes.…”

An examination of the association of serum IGF-I concentration, potential candidate genes, and fiber type composition with variation in residual feed intake in progeny of Red Angus sires divergent for maintenance energy EPD1

“…Energetic efficiency is an intricate process associated with and dependent on various factors, as noted above. Welch et al (2012) discussed sire ME M EPD in context of the relationship that may exist between maintenance energy and RFI, which also alluded to the importance of overall energetic efficiency. Based on this concept, measurements that could provide substantial input regarding variation in RFI were also analyzed in terms of sire ME M EPD.…”

“…For a more detailed description of sire selection, postweaning RFI evaluation, and finishing phase FE evaluation, refer to Welch et al (2012). In brief, a total of 12 Red Angus sires divergent for ME M EPD were chosen using the Red Angus Association of America-generated ME M EPD.…”