High‐energy diet improves growth performance, meat quality and gene expression related to intramuscular fat deposition in finishing yaks raised by barn feeding

Abstract

This research aimed to investigate the effects of dietary energy concentration (combined net energy, Nemf) on growth performance and meat quality of yaks raised by barn feeding. In all, 30 male yaks (3‐year old and 114.57 ± 21.56 kg of body weight) were allocated to one of three isonitrogenous dietary treatments that had different Nemf concentrations (low 3.72 MJ/kg, middle 4.52 MJ/kg and high 5.32 MJ/kg, respectively). The yaks were fed for 120 days. The results showed that the final weight, average daily gain, dressing percentage, backfat thickness and loin muscle area were significantly improved (p < .05) with the increase in dietary energy concentration. However, an opposite trend of feed:gain ratio, cooking loss, driage, shear force and moisture content was found. A significant improvement (p < .05) of intramuscular fat content was observed in the high‐energy group. Additionally, the proportion of polyunsaturated fatty acid was increased (p < .05) at the expense of the saturated fatty acids. The mRNA expressions of lipogenic genes fatty acid synthase, acetyl‐CoA carboxylase, sterol regulatory element‐binding protein 1, stearoyl‐CoA desaturase, peroxisome proliferator‐activated receptor γ, lipoprotein lipase and heart fatty acid‐binding proteins increased (p < .05) in a dose‐dependent manner. However, the mRNA expressions of lipolytic genes carnitine palmitoyltransferase‐1 and hormone‐sensitive lipase correspondingly decreased (p < .05) with increased dietary energy level. In summary, the growth performance, meat production and meat quality improvement of finishing yaks can be achieved by increasing the dietary energy concentration. The intramuscular fat accumulation of yaks was achieved through up‐regulation of intramuscular lipogenic gene expression as well as fatty acid transport gene expression and down‐regulation of lipolytic gene expression by promoting dietary energy concentration.

Dietary Energy Levels Affect Carbohydrate Metabolism-Related Bacteria and Improve Meat Quality in the Longissimus Thoracis Muscle of Yak (Bos grunniens)

“…Cooking loss and water holding capacity are important factors in evaluating the meat quality, which affect the juiciness of cooked meat ( 39 ). In the present study, the significant decreasing trend of cooking loss and water loss were observed with increasing dietary energy levels, which is consistent with the study of Kang et al ( 6 ). Shear force is an important indicator of meat tenderness.…”

“…meat (39). In the present study, the significant decreasing trend of cooking loss and water loss were observed with increasing dietary energy levels, which is consistent with the study of Kang et al (6). Shear force is an important indicator of meat tenderness.…”

“…Zhang et al ( 4 ) reported that supplementing a diet with high-protein in early-weaned yaks could increase intramuscular fat accumulation. Similarly, Kang et al ( 6 ) demonstrated that the growth performance, meat production, and meat quality of yak could be improved by increasing the dietary energy concentration. These results suggested that the dietary energy concentration has a positive impact on the growth performance, carcass characteristics, meat production, and meat quality of livestock.…”

Dietary Energy Levels Affect Rumen Bacterial Populations that Influence the Intramuscular Fat Fatty Acids of Fattening Yaks (Bos grunniens)

“…Petri et al [ 9 ] reported that the fatty acid profile in subcutaneous fat is related to rumen bacterial community composition. Our previous study showed that high dietary energy level significantly increased the longissimus dorsi intramuscular fat content, increased the polyunsaturated fatty acid (PUFA) content, and decreased the saturated fatty acid (SFA) content in the intramuscular fat of fattening yaks [ 10 ]. The intramuscular fat fatty acid profile is important for meat quality and human health; however, there is little information available about the correlativity between rumen bacterial populations and intramuscular fat fatty acid profiles in fattening yaks.…”

Lactobacillus improves meat quality in Sunit sheep by affecting mitochondrial biogenesis through the AMPK pathway

“…Therefore, improvement of the meat quality of Sunit sheep is vital and urgent. Kang et al ( 3 ) found that the deposition of intramuscular fat could improve the tenderness and water retention of meat. Nemati et al ( 4 ) discovered that vitamin E increased the antioxidant capacity of meat, which improved meat quality.…”