Effects of Altitude on the Digestion Performance, Serum Antioxidative Characteristics, Rumen Fermentation Parameters, and Rumen Bacteria of Sanhe Heifers

Abstract

The production efficiency of dairy cows is affected by altitude, with lower efficiency reported at higher altitudes. However, only a few studies have investigated the digestion performance, serum antioxidative characteristics, rumen fermentation performance, and rumen bacteria of Sanhe heifers at different altitudes. Therefore, in this study, we explored the effects of altitude on these aspects of Sanhe heifers. We evaluated the effects of altitude on the apparent digestibility of nutrients, serum antioxidative characteristics, rumen fermentation parameters, and rumen bacteria in Sanhe heifers. Twenty Sanhe heifers from the same herd and managed with the same practice were used. However, the heifers were from two regions in China: 10 were fed in Hulunbuir City, Inner Mongolia Autonomous Region (119°57′E, 47°17′N; approximately 700 m altitude, named LA) and 10 were fed in Lhasa City, Tibet Autonomous Region (91°06′E, 29°36′N; approximately 3,750 m altitude, named HA). The dry matter intake (DMI), average daily gain (ADG), and DMI/ADG ratio were higher (p < 0.05) in LA than in HA heifers, whereas the apparent total tract digestibility of dry matter, ether extract, and crude proteins were higher (p < 0.05) in the HA group. Compared with LA heifers, the HA heifers showed decreased (p < 0.05) serum concentrations of superoxide dismutase and glutathione peroxidase and increased serum concentration of hydrogen peroxide (p < 0.05). Altitude did not significantly affect the volatile fatty acid concentration in the rumen, but HA presented a lower acetate-to-propionate ratio than LA. The 16S rRNA gene sequencing data showed that altitude significantly affected the rumen microbial composition. At the phylum level, the HA heifers presented a lower relative abundance of Actinobacteria (p < 0.05) and higher relative abundance of Spirochaetae (p < 0.05) than the LA heifers. The correlation analysis revealed that the operational taxonomic units belonging to the genus Prevotella_1 were correlated (p < 0.05) with altitude and DMI. The results indicate that altitude can influence the apparent digestibility of nutrients, serum antioxidant capacity, rumen fermentation, and rumen bacteria composition of Sanhe heifers. The study provides insights into the adaptation mechanism of Sanhe heifers to high-altitude areas.

Effect of High Altitude on Serum Biochemical Parameters, Immunoglobulins, and Rumen Metabolism of Sanhe Heifers

“…In a previous study, we showed that different altitudes affect the rumen bacterial diversity of Sanhe heifers [21]. Changes in rumen microbiota structure may further affect differences in rumen metabolism.…”

Rumen microbiota of indigenous and introduced ruminants and their adaptation to the Qinghai–Tibetan plateau

“…In previous studies, we found that Jersey cattle showed adaptations to high altitude areas at both the miRNA and proteome levels ( Kong et al, 2019 ), illustrating adaptive mechanisms through up-regulation of amino acid metabolism and sphingolipid metabolism ( Kong et al, 2021 ). Zhang et al (2022) found that rumen fermentation and bacteria characteristic of highland Sanhe heifers had a lower acetate-to-propionate ratio as alternative hydrogen electron acceptors for CH 4 mitigation, a lower relative abundance of Actinobacteria, and higher relative abundance of Spirochaetae than that in rumen of lowland heifers. Cumulatively, these studies indicated that cattle introduced to the plateau also showed adaptations in phenotype and rumen fermentation microbiota.…”

“…In addition, low oxygen partial pressure, high altitude, strong UV radiation, Low precipitation, and poor forage availability on the alpine rangelands all present physiological challenges for its fauna ( Long et al, 1999 ; Yao et al, 2012 ; Liu et al, 2016 ; Friedrich and Wiener, 2020 ; Jing et al, 2022 ). Despite the challenges to husbandry associated with the need for enhanced adaptation, several domesticated ruminants have also been successfully introduced to the alpine pasture regions for meat and dairy production, such as hybrid sheep, goats, and cattle ( Huang et al, 2016 ; Zhang et al, 2022 ).…”

“…In order to fulfill requirements for life on the plateau, non-native sheep and cattle breeds have been introduced and crossbred with indigenous breeds, then naturalized to the QTP. For example, Gansu alpine fine wool sheep (a cross between Tibetan and Xinjiang fine wool sheep), Small-tail Han sheep, and Suffolk sheep are all found in alpine pastures of the QTP, as are Jersey cattle, Sanhe cattle, Simmental cattle, and Holstein cows, in addition to some crossbred cattle used for meat and dairy production ( Huang et al, 2016 ; Zhang et al, 2022 ).…”

Metagenomic and metabolomic analyses reveal differences in rumen microbiota between grass- and grain-fed Sanhe heifers

“…Sanhe cattle have rough feeding tolerance (Hu et al, 2019), strong disease resistance (Usman et al, 2017), and stable genetic performance. In previous reports, we introduced Sanhe cattle to an altitude of 3,650 m in Tibet and observed improved nutrient digestibility, indicating that Sanhe cattle exhibit strong adaptability to highaltitude environments (Zhang X. et al, 2022). However, the effects of feeding regimens on the composition and functions of gut microbiota in Sanhe heifers have not been explored.…”