Ruminants, Volume 2, Issue 2 (June 2022) – 10 articles

This study determined potential microbial and metabolic biomarkers of feed efficiency in Angus heifers. Seventeen ruminal cannulated Angus heifers underwent a 70-day feed efficiency trial. Residual feed intake was used to determine high and low feed efficient heifers. On day 70 of the trial, rumen content and blood were collected and used for microbial and metabolomic analyses, respectively. Bacterial populations were examined by targeting the V4 region of the 16S rRNA gene and analyzed using QIIME and SAS. Rumen fluid and serum metabolites were analyzed using MetaboAnalyst. No microbial taxa differed after false discovery rate correction, but seven did differ (p ≤ 0.05) prior to correction, including Lachnospiraceae (Other), Desulfobulbaceae, Neisseriaceae, Shuttleworthia, Corynebacterium, p-75-a5, and L7A-E11. No differences were observed in alpha diversity metrics. Beta diversity utilizing unweighted UniFrac distances analyzed via PERMANOVA was significant (p = 0.03). Several metabolites in rumen fluid metabolites were correlated with bacteria that differed by feed efficiency phenotype. The metabolites correlated with bacteria were primarily involved in nutrient signaling and microbial crude protein availability. These data suggest variation in the availability of nutrients, primarily amino acids, as well as a relationship among microbiota, metabolome, and host feed efficiency phenotypes in heifers. Full article

This paper summarizes the information on the Lagune cattle breed and its production systems in Benin available in peer-reviewed journals, conference papers and research reports covering the period from 1970 to 2020. Lagune cattle are kept in two production systems in Benin: the improved ranching system established at the Governmental farm of Samiondji, where most of the published studies on this breed have been achieved, and the village traditional production system. This breed has a small size with short horns. Reported adult weight varied from 140 to 180 kg for male and from 100 to 140 kg for female. Lagune cows are bad dairy. The breed plays an important role in the livelihoods of the rural people and has many functions, including cultural, ecological, socio-economic, savings and income provision roles. Most of the reports emphasizes its low productivity, which might rather be more related to its poor management conditions than to its genetic potential. The Lagune breed is reported to have adaptive traits such as tolerance to drought and heat, and resistance to ticks and diseases. In 1975, the Government of Benin, having realized the risk of the disappearance of this breed, devoted the Samiondji Farm to its ex situ conservation and set up a purebred multiplication herd. Since then, there have been very few efforts to comprehensively characterize this breed and its productivity under smallholder production systems. Consequently, the opportunities for its in situ conservation, management and sustainable use by the rural communities are not sufficiently explored. Full article

Environmental stressors have, over generations, influenced the morphology, anatomy, behaviour, physiology, and genetic structure of small ruminants. The widespread dispersal of small ruminants over vast geographical areas occurred along with human migration, thereby promoting the adaptative process to different environmental conditions mainly through natural selection. Ongoing global warming prompted scientific efforts to deepen the knowledge and understanding of adaptation traits in small ruminants. Compared to other ruminants, sheep and goats seem to have a better adaptation ability to environmental stressors, as evident by their presence across different geographic areas on a global level. Adaptation to a specific environment leads to variations in precise genomic regions, allowing for the identification and selection of animals with a high capacity of adaptation to environmental stressors. Rapid development in sequencing technologies, together with bioinformatics tools, make it possible to analyse the genomic regions related to environmental adaptation. Hence, the aims of this review were (i) to outline the main steps of the evolution process in sheep and goat species, (ii) to summarise candidate genes related to environmental adaptation, and (iii) to evaluate both selection and conservation possibilities of these genes in native small ruminant breeds for future challenges to better face the global warming. Full article

Predicting feed intake in suckling lambs consuming both milk and pasture can be challenging, and thus intake values are often derived from solely milk or solid feed consumption. The present study investigated if dry matter (DM), organic matter (OM), and metabolisable energy (ME) intakes of lambs given a combination of milk and pellets under controlled conditions could be predicted with enough precision using dietary and faecal chemical composition. A total of 34 pre-weaned lambs bottle-fed milk replacer with or without access to pellets and kept in metabolic cages for four days were used. To develop the prediction equations, 54 faecal samples with detailed information on their chemical compositions, and the feed consumed by the lambs, were used. Pellet DMI was predicted from neutral detergent fibre concentration in faeces and pellets, pellets %DM, and live weight (LW) of lambs. Milk DMI was predicted from faecal Nitrogen concentration and LW. Milk and pellet DMI and their ME content were combined to predict DMI/d and ME intake/d. The equations developed were validated against 40 spot faecal samples randomly selected from the lambs. DM, OM, and ME intakes were predicted with high accuracy and precision. The results showed that the developed equations can be used with enough accuracy to predict ME, OM, and DM intakes in pre-weaned lambs ingesting milk and pellets concurrently, thus the results revealed that the established equations may be used to predict ME, OM, and DM intakes in pre-weaned lambs drinking milk and pellets at the same time, allowing feeding regimens for young lambs to be developed. Full article

Butyrate is produced by microbe fermentation in the rumen, and its supplementation results in rumen development. Butyrate-induced experiments are valuable in studying nutrient metabolism, cell growth, and functional genomics. This study aimed to characterize accessible chromatin regions and the dynamics of genomic accessibility prompted by butyrate-induced histone modifications in bovine cells. An average of 117,569 accessible chromatin regions were identified for all samples, and 21,347 differentially accessible regions (DARs) for butyrate. Most of the DARs were in distal intergenic regions, introns, and promoters. Gene ontology enrichment resulted in important terms related to the digestive system, regulation of epithelial cells, and cell adhesion. Ingenuity Pathway Analysis (IPA) identified critical networks (e.g., digestive system development, cell morphology and assembly, and cell cycle); canonical pathways (e.g., TGFβ, Integrin-linked kinase, and epithelial adherens junction); and upstream regulators (e.g., TGFβ1, FOS, JUNB, ATF3, and KLFs). Co-expression analysis further showcased the TGFβ and Integrin-linked kinase (ILK)-signaling pathways, which play roles in rumen development through cellular adhesions. This study is the first to provide a genome-wide characterization of differential, open chromatin regions for bovine cells by butyrate-induced treatment. These results provide valuable information for future studies of the butyrate functions in cattle gastrointestinal tract development. Full article

The inclusion of fresh forages into dairy cows’ diets during the winter can represent economic and nutritional benefits but can affect cows’ metabolic function. The study aimed to evaluate the effect of using fresh berseem clover/oat (MIX), fresh lucerne (LEG) and hay/silage (CON) as forage basis for total mixed ration during the winter period on dairy cows’ rumen characteristics and N metabolism. Three non-lactating rumen-cannulated cows were allocated to each diet for a 14-day period in a 3 × 3 Latin Square design. Sample collection occurred on the last 3 days of each period. Rumen fluid samples were analysed for pH, volatile fatty acids and N-ammonium contents. In situ forage nutrients degradability were evaluated by ruminal incubation. Serum, urine and faecal samples were collected and analysed for N content. Cows had similar feed intakes. No major changes were observed in rumen characteristics, but LEG led to greater ruminal N-ammonium and ammonium ureic N contents. Fresh pasture diets reduced the daily urine ureic N. The fresh forages improved the ruminal kinetics of dry matter and crude protein. The forage nutrients’ effective degradability was greater for the fresh pasture diets than for CON. Overall, inclusion of fresh forages had minor effects on ruminal parameters, but the use of the MIX diet represents a suitable option in terms of N use efficiency. Full article

(1) Background. Merino is a worldwide sheep breed well known for the quality and quantity of its wool. If there is no doubt that it originates from the Mediterranean Basin and that human selection took place in southern Spain, the populations that potentially contributed to the building of this breed are a matter of debate. Here, we tested whether a Moroccan breed settled on the North Atlantic coast, the Beni Ahsen, could be a good candidate, given the thickness and distribution of fleece covering the head and legs. (2). Methods. Using the control region of the mtDNA, 20 Beni Ahsen sequences were considered in a dataset of 643, including Mediterranean Merino and non-Merino breeds. Unfortunately, the Beni Ahsen is an endangered breed because of a lack of interest from the breeders. (3) Results. European Merino-derived breeds are divided into an Iberian and an Italian cluster, more linked to non-Merino breeds of the same country than between Merino themselves. Beni Ahsen breed is strongly linked to the other Moroccan breeds but shows the greatest number of connections with Merino-derived breeds, especially from Iberia. Interestingly, several other Moroccan breeds are also connected to Iberian Merino. Full article

The synchronous supply of energy and nitrogen (N) substrates to the rumen microbes on grass silage (GS)-based diets can potentially lead to reduced levels of N excreted in the urine. The objective of this study was to evaluate the effect of supplementing GS-based diet with carbohydrate sources differing in rumen fermentation profile on N metabolism of beef heifers. Six Belgian Blue × Holstein Friesian cross beef heifers (487 ± 29 kg BW) were used in a 3 × 3 Latin Square design (n = 6). Dietary treatments were: (RB) GS supplemented with rolled barley; (MM) GS supplemented with maize meal and; (SH) GS supplemented with soya hulls offered at 40:60 forage to concentrate ratio on a dry matter (DM) basis, at maintenance feeding (40 g DM/kg BW^0.75). Carbohydrate source had no effect on DM, organic matter, or N intake or total N excretion and the amount of N excreted in the urine (p > 0.05). Animals offered MM excreted a higher percentage of N in the faeces and a lower percentage of N in the urine compared to animals offered RB (p < 0.05). There was a time by interaction for ruminal ammonia (NH₃) concentrations (p < 0.01). Ruminal NH₃ concentrations peaked at 2 h post-feeding for all treatments. At 3 h post-feeding, ruminal NH₃ concentrations for the RB treatment remained higher compared to MM and SH treatments. Molar proportions and total ruminal volatile fatty acids were similar among dietary treatments (p > 0.05). Supplementing GS-based diets with different carbohydrate sources had no impact on the total level of N excreted or the amount of N excreted in the urine. However, there was a higher percentage of N excreted in the faeces and a lower percentage of N excreted in the urine when animals were offered MM compared to those offered RB (p < 0.05). Full article

The Maraichine breed of cattle originates from the Loire region of France and has been under a conservation programme since 1986. This programme links the conservation of the breed with the conservation of its traditional environment of wet grasslands. In this case report, we describe the different steps of this programme, each of which had its own successes and challenges. We also describe how, throughout this process, researchers have been involved in the generation and dissemination of information covering areas such as stakeholder perspectives, animal performance, and socio-economics. Under the conservation programme, the Maraichine population has expanded in both size and scale. Simultaneously, stakeholder perspectives have also developed, continually shifting the balance between the productivity, conservation, and maintenance of heritage traits. The conservation programme also provided the opportunity to utilise the breed’s desirable traits, such as easy calving and disease resistance. Whilst the carcasses are not necessarily as valuable as those of other breeds, farmers have implemented novel economic practices to capitalise on market opportunities. Today, Maraichine cattle and Maraichine breeders offer researchers the opportunity to deepen and enrich our knowledge on sustainable ruminant livestock farming systems. Full article

Climate change is accompanied by temperatures exceeding the thermal comfort zone of dairy cows, resulting in numerous consequences for production and welfare. Early detection of heat load enables taking countermeasures and can be realized using monitoring systems. We aimed at investigating heat load-induced changes in the behavior and physiology of grazing Simmental cows. Data were collected on five (round 1; r1) and eight (round 2; r2) consecutive days on a dairy farm combining a freestall barn with permanent access to pasture. Weather data, respiration rate, milk yield, milk composition, and fecal cortisol of eleven (r1) and thirteen (r2) cows were collected. The behavior of five animals was recorded with collar-based monitoring systems. Previously reported thresholds of different weather indices were exceeded on two days in r1 and on four days in r2. Under heat load, respiration rate and somatic cell count increased. Fecal cortisol did not change in r1 but increased steadily in r2. Grazing time decreased in r1. Rumination mainly occurred at night in both rounds, and its synchrony decreased in r2. Although limited by sample size, our results give a first impression on heat load induced physiological and behavioral reactions of Simmental dairy cows on pasture. Full article