Apart From the Diet, the Ruminal Microbiota of Lambs Is Modified in Relation to Their Genetic Potential for Feed Efficiency or Feeding Behavior

Using two successive types of diets (100% concentrate and 67% forage), this study explores the relationship between the ruminal microbiota of 78 Romane lambs and their feed efficiency (residual feed intake trait) or feeding behavior (feeding rate trait). Analysis was carried out phenotypically by correlating feed efficiency or feeding behavior traits with the relative abundance of bacteria at the phylum, family, and genus levels, and then genetically by comparing the microbiota of lambs selected for extreme breeding values for residual feed intake or feeding rate. Our results confirmed the major effect of diet on the ruminal microbiota composition. The microbiota of lambs consuming a forage-based diet was distinguished by higher microbial diversity and also by higher relative abundance of Firmicutes, whereas Bacteriodetes and Actinobacteria were relatively more abundant in the microbiota of lambs consuming a concentrate-based diet. Moreover, the comparison of lambs divergent for residual feed intake breeding values revealed that regardless of diet, more efficient lambs possessed a ruminal microbiota enriched in Coprococcus, Moryella, [Eubacterium] Brachy group, and [Eubacterium] hallii group, but depleted in Lachnospiraceae FD2005 and Shuttleworthia. The connection between microbiota composition and feeding rate was more tenuous, with no link between the abundance of particular genera and lambs genetically divergent for feeding rate.

Standardized Natural Citrus Extract dietary supplementation influences sows’ microbiota, welfare, and preweaning piglets’ performances in commercial rearing conditions

We investigated the effect of the Standardized Natural Citrus Extract (SNCE; Nor-Spice AB, Nor-Feed SAS, France) on the microbiota of the sows and on the weight gain of their piglets. Fifty sows were randomly divided into two groups: a control group (23 sows) with a standard diet and a SNCE group (27 sows) with a standard diet supplemented with 2,500 ppm of SNCE. Supplementation occurred 10 d before and 5 d after farrowing. Fecal samples from 16 sows (8 randomly selected sows of each dietary treatment) were collected for the fecal microbiota analysis 5 d after farrowing. The supplementation of SNCE increases the amount of cultivable Lactobacillus threefold in vitro. Microbial DNA was extracted from the fecal samples for sequencing of the 16S rRNA gene. The SNCE, which affected the microbiota as a discriminant analysis, was able to separate the microbial communities of the eight sows that received SNCE from the three control sows with 21 Operational Taxonomic Units (area under the ROC curve = 96%). SNCE also reduced the interval between farrowing and the first dejection of the sow and increased their feed intake (P-value < 0.05). Furthermore, feeding the sows with SNCE improved the weight gain of the piglets in the first week of life. These results show that SNCE supplementation allows to enhance zootechnical performances of peripartum’ sows, possibly due to the modulation of the microbiota transmitted to the piglets.

Diversity and Co-occurrence Pattern Analysis of Cecal Microbiota Establishment at the Onset of Solid Feeding in Young Rabbits

This study aimed to evaluate how the feeding strategy of rabbit kits at the onset of solid feed intake could affect ecological diversity and co-occurrence patterns of the cecal bacterial community. From birth to 18 days of age kits were exclusively milk-fed, and between 18 and 35 days the young rabbits also had access to solid feed. After weaning at (35 days), young rabbits were exclusively fed solid feed. Three experimental feeds were used: a high concentrate diet [H: 10.16 MJ digestible energy (DE)/kg and 15.3% crude protein (CP)], a low concentrate diet (L: 9.33 MJ DE/kg and 14.7% CP) and a reproductive female diet (R: 10.57 MJ DE/kg and 17.3% CP). The rabbit kits (n = 357) were divided into three groups, differing by the diet received during two periods: from 18 to 28 and from 28 to 49 days of age. In the groups LL and HH, rabbit kits were fed L or H diets, respectively, during both periods. Kits in the group RL received feeds R and L from 18 to 28 and 28 to 49 days of age, respectively. Cecal bacterial communities of 10 rabbits per group were carried out at 18, 28, 35, 43 and 49 days of age by MiSeq Illumina sequencing 16S rRNA encoding genes. Between 18 and 28 days of age, solid feed intake was higher in the group RL compared to the other two groups (+24%; P < 0.01). Overall, 13.4% of the OTUs detected were present in the cecal ecosystem from 18 to 49 days old, whereas 17.4% were acquired with the onset of solid feeding and kept from 28 days on. Exclusive milk consumption constrains the bacterial community toward a similar structure but high phylogenetic beta-diversity. Introduction of solid feed induced a sharp change of microbial community structure and decreased phylogenetic diversity. A strong relationship in bacterial community network occurred only from 43 days on. Our feeding strategy at the onset of solid feed ingestion exhibited only a moderate effect on the microbial community structure (P = 0.072), although the LL group seemed to reach faster maturity compared to the two other groups.

Type-specific changes in fibre size and satellite cell activation following muscle denervation in two strains of turkey (Meleagris gallopavo)

Morphological features and the chronology of muscle changes after denervation were studied over a 21 d period in 2 heavy (HW) and light-weight (LW) strains of 6-wk-old male turkeys. The atrophy of tibialis cranialis, gastrocnemius lateralis and plantaris muscles was apparent at d 3 after denervation. By d 21 the weight of these muscles had reached 45-60% of that of nondenervated contralateral muscle. Cellular lesions, such as irregularities in mitochondrial distribution or coagulative necrosis with fragmentation and lysis associated with moderate infiltration of inflammatory cells, were similar in both strains. Ten days after denervation, immunolabelling of a proliferating cell nuclear antigen (PCNA) expressed during the G1 and S phase of the cell cycle revealed satellite cell activation in denervated muscles. The number of satellite cells activated at d 21 was markedly greater in the HW than LW strain. Morphometric analysis revealed that fast twitch (type II) fibres were atrophied after denervation, whereas slow-twitch (type I) and slow tonic (type III) fibres were hypertrophied from d 10. Hypertrophy occurred more rapidly in the LW than HW strain.