ABSTRACT
Meat quality is important in the meat-production chain. Conflicting reports of the effects of feeding systems on sheep growth performance and meat quality exist. By way of meta-analysis, we reviewed the literature on the growth and slaughter performance, and meat quality of lambs that grazed solely on pasture, those that grazed on pasture but received a dietary supplement, and those were exclusively fed indoors. The relevant literature comprised 28 papers, from which response variables of interest were obtained. Compared with stall-fed sheep, pasture-grazing led to significantly (p < 0.05) lower average daily gain, slaughter live weight, hot carcass weight, cold carcass weight, and similar dressing percentage, but pasture-grazed sheep fed a supplement had similar (p > 0.05) values for each of these attributes to stall-fed sheep. The quality of the longissimus muscle from lambs that grazed either exclusively on pasture or pasture with a supplement had significantly (p < 0.05) lower lightness and intramuscular fat content, and significantly (p < 0.05) higher yellowness, Warner-Bratzler shear force, and protein content than meat from stall-fed sheep. We conclude that sheep that have fed exclusively on pasture have lower carcass yield and meat edibility, but improved meat quality, and that pasture-fed sheep that received a supplement had comparable carcass attributes, but greater meat color and health quality than stall-fed sheep.
ABSTRACT
The aim of this study was to determine whether the inclusion of 40% of common vetch (CV) hay as a feed ingredient in place of alfalfa hay (AH) would improve performance and ruminal fermentation and microbiota in fattening lambs. Twenty lambs were equally divided into two groups: control group (fed 40% AH with 20% rice straw) and CV group (fed 40% CV hay with 20% rice straw). Concerning hay quality, CV hay had greater in vitro digestibility of dry matter and neutral detergent fiber (p < 0.05) than AH. Lambs fed the CV diet had a higher average daily gain (ADG) and efficiency of feed and economy than lambs fed the control group. The NH3-N content and estimated methane produced per unit of ADG of the CV diet group were significantly lower (p < 0.05) than control group. Multiple differential microbial genera were identified, with Prevotella being the most dominant genus and a tendency towards higher (p = 0.095) in lambs offered CV diet. The higher Ruminococcus abundance (p < 0.05) was found in animals of the CV group compared to the control group. In summary, CV can be incorporated into lamb diets as a low-cost forage alternative to AH to improve feed efficiency and animal performance and to reduce methane produced per unit of ADG.