Effects of Replacing Alfalfa Hay With Native Grass Hay in Pelleted Total Mixed Ration on Physicochemical Parameters, Fatty Acid Profile, and Rumen Microbiota in Lamb

Abstract

This study aimed to investigate the effects of replacing alfalfa with native grass on growth performance, meat quality, and rumen microbiota of lambs. Forty-five 6-month-old Ujimqin lambs with live body weight (BW) of 29.50 ± 0.26 kg were used for the experiment, and the lambs were assigned to three diet treatments (three pens per treatment and five lambs per pen) with 30 square meters per pen in semi-open housing based on similar BW. The lambs have received 30% alfalfa (HA, high alfalfa percentage group), 20% alfalfa (MA, moderate alfalfa percentage group), and 10% alfalfa (LA, low alfalfa percentage group) diets, respectively (dry matter basis). The diet treatments had a significant (P < 0.05) influence on the dry matter intake of lambs and the dry matter intake increased with the increasing percentages of native grass hay, while the significantly (P < 0.05) lower final BW and average daily gain were observed in the MA and LA groups compared with that in the HA group. The diet had a significant (P < 0.05) difference in meat pH value, water loss rate, cooked meat rate, moisture, and intramuscular fat, while no significant (P > 0.05) difference was found in protein. As native grass hay percentages increased in the diet, the contents of palmitic (C16:0) and palmitoleic (C16:1 cis-9) in the HA and MA groups were significantly (P < 0.05) lower than that in the LA groups, and compared with the HA group, the contents of elaidic (C18:1 trans-9), oleic (C18:1 cis-9), and linoleic (C18:2 cis-9–cis-12) were significantly (P < 0.05) increased in the MA and LA groups. The content of α-linolenic (C18:3n3) was significantly (P < 0.05) higher in the LA group than that in the HA and MA groups. The principal coordinate analysis profile displayed that the composition of the bacterial community of these groups was distinctly separated from each other. No significant (P > 0.05) difference was observed in the dominant rumen bacteria at the phyla and genus levels. In conclusion, the meat quality and fatty acid profile analysis revealed that replacing alfalfa hay with native grass hay is more beneficial for Mongolian lambs, and the meat from LA diet treatment is better than the others. In addition, correlation analysis of the association of rumen microbiome with growth performance, meat quality, and fatty acid profile provides us with a comprehensive understanding of the composition and function of rumen microbiota. These findings could provide knowledge of how the diet affects the animal performance, meat quality of lambs, and microbiota of the rumen, laying a theoretical basis for replacing alfalfa with native grass.

Diversity of growth performance and rumen microbiota vary with feed types

“…Indeed, the different substrates of the diet affect the growth of rumen microbiota (Maslowski and Mackay, 2011;Li et al, 2012;Kasparovska et al, 2016). Previous reports found that Prevotella_1, Rikenellaceae_RC9_gut_group, F082_unclassfied, and Succinivibrio were the genera of the core-microbiome (Du et al, 2022;Zhou et al, 2022). In the present study, these genera were influenced by the physical forms and chemical compositions, whereas the stability of the most abundant bacteria can reflect the presence of the genus-core microbiome (Henderson et al, 2015;Lin T. et al, 2021).…”

“…At intervals of 7 days, the initial BW and the final BW were also recorded. The growth performance was analyzed based on the difference between the final BW and the initial BW (Du et al, 2022). At the end of the experiment, all of the lambs were transferred and slaughtered at a commercial slaughterhouse (Xilin Hot, China).…”

“…Additionally, some studies indicated that high-concentrate diets could affect the composition of the rumen microbiota (Plaizier et al, 2012), and high-forage diets are beneficial for some microorganisms, such as those in the genus Firmicutes (Khafipour et al, 2009). Previous reports also found that the growth performance, carcass traits, and meat quality of lambs were significantly influenced by the native grass diet on the Mongolian Plateau (Du et al, 2019(Du et al, , 2022Bu et al, 2021). However, the related research about the effects of non-pelleted native grass without or with concentrate or pellets on the ruminal microbiota is still limited.…”

Silage Mixtures of Alfalfa with Sweet Sorghum Alter Blood and Rumen Physiological Status and Rumen Microbiota of Karakul Lambs

“…It indicated that feeding different ratios of AF in the AF–SS silage-based diets had an effect on the microbiota composition of lambs. Du et al [ 41 ] reported that the composition of the bacterial community of lambs fed diets with 10%, 20%, 30% AF inclusion was distinctly separated according to PCoA analysis, which indicated that different bacteria prefer different nutrients and ruminal environments.…”

Longitudinal Investigation of the Native Grass Hay from Storage to Market Reveals Mycotoxin-Associated Fungi

“…The common and unique OTUs was used to construct the Venn diagram by R (version 1.6.2). The alpha diversity for these samples were used the Chao1 value and Shannon index to evaluate richness and diversity [17][18][19][20], and Good's coverage were calculated through QIIME software. Principal coordinates analysis (PCoA) was conducted on OTU level by R (version 3.3.1) software based on weighted UniFrac distances.…”