Palma-Hidalgo Juan Manuel, Jiménez Elisabeth, Popova Milka, Morgavi Diego Pablo, Martín-García Antonio Ignacio, Yáñez-Ruiz David Rafael, Belanche Alejandro
Estación Experimental del Zaidín (CSIC), Profesor Albareda 1, 18008, Granada, Spain.
Université Clermont Auvergne, INRAE, VetAgro Sup, UMR Herbivores, F-63122, Saint-Genès Champanelle, France.
Anim Microbiome. 2021 Jan 19;3(1):11. doi: 10.1186/s42523-021-00073-9.
Newborn ruminants possess an underdeveloped rumen which is colonized by microorganisms acquired from adult animals and the surrounding environment. This microbial transfer can be limited in dairy systems in which newborns are separated from their dams at birth. This study explores whether the direct inoculation of fresh or autoclaved rumen fluid from adult goats to newborn kids has a beneficial effect on rumen microbial development and function.
Repetitive inoculation of young kids with fresh rumen fluid from adult goats adapted to forage (RFF) or concentrate diets (RFC) accelerated microbial colonization of the rumen during the pre-weaning period leading to high protozoal numbers, a greater diversity of bacterial (+ 234 OTUs), methanogens (+ 6 OTUs) and protozoal communities (+ 25 OTUs) than observed in control kids (CTL) without inoculation. This inoculation also increased the size of the core bacterial and methanogens community and the abundance of key rumen bacteria (Ruminococcaceae, Fibrobacteres, Veillonellaceae, Rikenellaceae, Tenericutes), methanogens (Methanobrevibacter ruminantium, Methanomicrobium mobile and Group 9), anaerobic fungi (Piromyces and Orpinomyces) and protozoal taxa (Enoploplastron, Diplodinium, Polyplastron, Ophryoscolex, Isotricha and Dasytricha) before weaning whereas CTL kids remained protozoa-free through the study. Most of these taxa were positively correlated with indicators of the rumen microbiological and physiological development (higher forage and concentrate intakes and animal growth during the post-weaning period) favoring the weaning process in RFF and RFC kids in comparison to CTL kids. Some of these microbiological differences tended to decrease during the post-weaning period, although RFF and RFC kids retained a more complex and matured rumen microbial ecosystem than CTL kids. Inoculation with autoclaved rumen fluid promoted lower development of the bacterial and protozoal communities during the pre-weaning period than using fresh inocula, but it favored a more rapid microbial development during the post-weaning than observed for CTL kids.
This study demonstrated that inoculation of young ruminants with fresh rumen fluid from adult animals accelerated the rumen microbial colonization which was associated with an earlier rumen functional development. This strategy facilitated a smoother transition from milk to solid feed favoring the animal performance during post-weaning and minimizing stress.
新生反刍动物的瘤胃发育不全，其微生物群落是从成年动物和周围环境中获得的。在奶牛养殖系统中，新生动物出生时即与母体分离，这种微生物转移可能会受到限制。本研究探讨了直接向新生山羊接种成年山羊的新鲜或高压灭菌瘤胃液是否对瘤胃微生物的发育和功能有有益影响。
用适应牧草（RFF）或精料日粮（RFC）的成年山羊的新鲜瘤胃液反复接种幼羊，在断奶前加速了瘤胃微生物的定殖，导致原生动物数量增加，细菌（+234个OTU）、产甲烷菌（+6个OTU）和原生动物群落（+25个OTU）的多样性高于未接种的对照幼羊（CTL）。这种接种还增加了核心细菌和产甲烷菌群落的规模以及关键瘤胃细菌（瘤胃球菌科、纤维杆菌属、韦荣球菌科、理研菌科、柔膜菌纲）、产甲烷菌（瘤胃短杆菌、运动甲烷微菌和第9组）、厌氧真菌（梨形霉属和奥尔平霉属）和原生动物类群（内质体属、双滴虫属、多质体属、腹毛虫属、等毛虫属和达氏毛虫属）在断奶前的丰度，而CTL幼羊在整个研究过程中一直没有原生动物。这些类群中的大多数与瘤胃微生物和生理发育指标呈正相关（断奶后较高的牧草和精料摄入量以及动物生长），与CTL幼羊相比，有利于RFF和RFC幼羊的断奶过程。尽管RFF和RFC幼羊的瘤胃微生物生态系统比CTL幼羊更复杂和成熟，但这些微生物学差异在断奶后趋于减小。与使用新鲜接种物相比，接种高压灭菌瘤胃液在断奶前促进细菌和原生动物群落的发育较低，但与CTL幼羊相比，它在断奶后促进微生物发育更快。
本研究表明，用成年动物的新鲜瘤胃液接种幼龄反刍动物可加速瘤胃微生物定殖，这与瘤胃功能的早期发育有关。这种策略有助于从牛奶到固体饲料的更平稳过渡，有利于断奶后的动物性能，并最大限度地减少应激。
