Effect of summer forage species grazed during finishing on animal performance, carcass quality, and meat quality1,2

Abstract

Angus-cross steers (n = 60) were used to assess the effect of forage species [alfalfa (AL; Medicago sativa L.), bermudagrass (BG; Cynodon dactylon), chicory (CH; Cichorium intybus L.), cowpea (CO; Vigna unguiculata L.), and pearl millet (PM; Pennisetum glaucum (L. R Br.)] in replicated 2-ha paddocks for finishing on cattle performance, carcass quality, and meat quality in a 2-yr study. Steers were blocked by BW and assigned randomly to finishing-forage treatments before the start of the experiment. Steers grazing AL and CH had greater (P < 0.05) ADG than those grazing for BG, CO, and PM, whereas AL produced more (P < 0.05) gain/ha than CH, CO, and PM. Days steers spent grazing were longest (P < 0.05) for PM and shortest (P < 0.05) for CO. Steers grazing BG and CO produced heavier (P < 0.05) HCW than steers grazing BG and PM. Dressing percentage was greatest (P < 0.05) in steers grazing CO, and grazing AL resulted in greater (P < 0.05) dressing percentages than grazing BG, CH, and PM. Grazing AL and CH produced carcasses with more (P < 0.05) fat at the 12th rib than steers grazing warm-season grasses (BG and PM). Marbling scores tended to be greater (P = 0.06) for CO, but carcasses from steers grazing CO received greater (P < 0.05) quality grades than AL and CH. Trans-11 vaccenic (C18:1 trans-11; TVA) acid concentration in the LM was greater (P < 0.05) for BG than CH, CO, and AL. Conjugated linoleic acid, cis-9 trans-11 isomer, concentration was greatest (P < 0.05) for BG and PM than AL, CH, and CO. Grazing CH and PM increased (P < 0.05) the ratio of omega-6 to omega-3 fatty acids in the LM compared with AL, BG, and CO. Grazing legumes (AL and CO) resulted in lower (P < 0.05) Warner-Bratzler shear force values than other forage species. Consumers rated steaks from steers finished on AL and CO pastures greatest (P < 0.05) and steaks from steers finished on BG and CH least (P < 0.05) for overall palatability. Consumer preference was greatest (P < 0.05) for steaks from steers finished on AL and least (P < 0.05) for steaks from steers finished on BG and CH. Finishing steers on AL and CH during summer increased steer performance (> 1 kg/d). Finishing on legumes (AL and CO) increased dressing percentage, reduced Warner-Bratzler shear force values, and increased consumers preference, whereas finishing on grasses (BG and PM) enhanced anticarcinogenic fatty acid concentrations.

Stability, fatty acid composition and sensory properties of the M. Longissimus muscle from beef steers grazing either chicory/ryegrass or ryegrass

“…Our findings are in contrast to the research comparing beef from steers grazing chicory to bermudagrass, cowpea, lucerne or pearl millet, where it was found that consumers preferred steaks from steers finished on all other treatments compared with chicory or bermudagrass (Schmidt et al, 2013). Although it is difficult to draw comparisons between cattle and sheep given species differences in grazing efficiencies and intakes of chicory (McCoy et al, 1997), research looking at pure chicory swards compared with ryegrass in finishing lamb systems found, in agreement with our study, that including chicory in the diet of grazing lambs did not have any substantive effects on meat eating quality (Houdijk et al, 2011).…”

“…That stated, fatty acid profiles have been shown to differ among forages, with chicory reported as having higher concentrations of C18 : 3 when compared with grasses (including ryegrass), plantain, turnips, rape, triticale and borage (Clapham et al, 2005). In contrast to the current study, other research found that grazing beef steers on chicory increased the ratio of n-6 to n-3 fatty acids in the meat when compared with steers grazing bermudagrass, cowpea or lucerne but not those grazing pearl millet (Schmidt et al, 2013). Further research into the fatty acids profiles in chicory when grown and managed under different environmental conditions are now required to determine if feeding chicory to cattle could be used as an effective approach to improving beef fatty acid composition, with potentially beneficial consequences for human nutrition (Scollan et al, 2006).…”

“…Fatty acid profiles have been shown to differ among forages, with chicory reported as having a different profile and a higher total concentration of PUFA (C18 : 3n-3) than other forages including ryegrass (Clapham et al, 2005). In the experiment by Schmidt et al (2013), chicory increased the ratio of n-6/n-3 PUFA in the meat of grazing steers when compared with steers grazing bermudagrass, cowpea or lucerne, suggesting that including chicory in the diet of grazing ruminants would alter the total fatty acid concentration and composition of their meat.…”

“…Most notably, degradation products of sesquiterpene lactones found in chicory, namely dihydrolactucin, tetrahydrolactucin and hydroxypenyacetic acid, were identified as the taint compounds in the milk of dairy cows on high chicory diets (Visser, 1992), leading to speculation that the same compounds could result in meat with a bitter taste compared with meat from grass-based systems. In a recent study, consumers preferred steaks from steers finished on pearl millet (Pennisetum glacum), cowpea (Vigna unguiculata) or lucerne (Medicago sativa) when compared with steaks from steers grazing chicory or bermudagrass (Cynodon dactylon) (Schmidt et al, 2013).…”

Effect of Cowpea (Vigna unguiculata) Pasture Grazing on Growth, Gastrointestinal Parasite Infection and Immune Response Biomarkers of Goat

“…Cowpea plants are grazed by cattle (Pitman et al, 2015), and sheep and goats (Mubi, Midau & Hamdalla, 2015;Adjei-Fremah, 2016c) as a summer legume. More recently, cowpea used as a summer finishing diet in cattle resulted in improved meat quality and marbling score, and higher consumer steak preference (Schmidt et al, 2013). It is important to understand goat growth and health performance when allowed to graze fresh cowpea pasture.…”