The objective of this experiment was to determine effects of peripheral blood mononuclear cells (PBMC), derived from parasite-resistant St. Croix (STC) and parasite-susceptible Suffolk (SF) sheep, on motility of Haemonchus contortus L stage larvae in vitro. Peripheral blood mononuclear cells were collected from 10 lambs of each breed, 5 naïve and 5 which had received a priming infection with H. contortus. Larval motility was quantified using a MIF Nikon Sweptfield microscope and NIS Elements AR software, and measurements included path length (PL) (μm), velocity (VEL) (μm/s) and acceleration (ACC) (μm/s ). After 18 h of incubation, PL and VEL were greatest in larvae cultured with SF-derived PMBC and were significantly different from all other groups (P < 0·01). No difference was observed in PL or VEL between larvae exposed to naïve or primed STC-derived PBMC and primed-SF PBMC. Differences in ACC were detected between larvae cultured with primed STC-derived PBMC (10·91 μm/s ) and naïve SF-derived PBMC (45·7 μm/s ) (P = 0·035). These data indicate an innate ability of STC-derived PBMC to severely inhibit larval motility.

The objective of this study was to determine the effects of peripheral blood mononuclear cells (PBMC), derived from parasite-resistant St. Croix (STC) hair sheep and parasite-susceptible Suffolk (SUF) sheep, on Haemonchus contortus L stage larval death in vitro, with or without autologous serum. Larval morbidity was quantified by measuring larval ATP concentration following incubation with PBMC. Larvae exposed to either STC- or SUF-derived PBMC had lower ATP than live larvae (0.12 μmol/L ATP and 0.16 μmol/L ATP vs 0.27 μmol/L ATP, respectively) (P<.001) and greater ATP of dead larvae (0.03 μmol/L ATP) (P<.001). Breed differences were observed with addition of autologous serum. Larvae exposed to SUF-derived PBMC with autologous serum were not significantly different from live larval ATP. STC-derived serum did not significantly reduce larval ATP compared to PBMC alone (0.11 μmol/L ATP), but was significantly reduced compared to live larvae (0.22 μmol/L ATP) and SUF-derived PBMC with autologous serum (0.23 μmol/L ATP) (P<.001). These data indicate that a cellular response alone is capable of significantly reducing larval ATP in a breed-independent manner. However, addition of serum to SUF-PBMC failed to reduce larval ATP, indicating breed-dependent humoral response to H. contortus.

The effect of ovine peripheral blood mononuclear cells on Haemonchus contortus larval death in vitro Elizabeth Anne Shepherd Gastrointestinal nematode parasitism is the greatest problem facing small ruminant livestock, largely due to development of anthelmintic resistance. Of particular concern is Haemonchus contortus, a hematophagous trichostrongylid that can lead to death in lambs or immunocompromised sheep. Some breeds of sheep are resistant to Haemonchosis, e.g. St. Croix (STC) hair sheep. St. Croix sheep have well-documented resistance and have been shown to develop a robust immune response, generating a rapid cellular response to larval stages that does not occur in susceptible sheep. Studies evaluating effects of mononuclear cells, including monocytes and lymphocytes, indicate that these cells dramatically reduce motility of H. contortus larval motility in vitro. Furthermore, breed affected larval motility. However, lack of motility may also have been caused by immune cell trapping. In this study, the impact of peripheral blood mononuclear cells (PBMC) on H. contortus larvae in the presence or absence of autologous serum was measured by larval ATP. Viability of larvae was tested by measuring fecal egg count (FEC) after infecting susceptible sheep with PBMC-exposed larvae. Larvae exposed to STC-derived or Suffolk (SUF)-derived PBMC had lower (P < 0.001) ATP than live larvae (0.12 µM ATP and 0.16 µM ATP) (0.27 µM ATP). Larvae exposed to PBMC from both breeds were greater than dead larval ATP (0.03 µM ATP) (P < 0.001). Larval ATP was lower when exposed to STC-derived PBMC with serum (0.11 µM ATP) than SUF-derived PBMC with serum (0.23 µM ATP) or live (0.22 µM ATP) (P < 0.001). There was no significant difference between live larvae and larvae treated with SUF-derived PBMC with serum. Taken together, these data indicate a cellular response alone is capable of significantly lowering larval ATP. However, the addition of serum to SUF-PBMC failed to reduce larval ATP, suggesting differences in humoral response in mediation of H. contorus.

The rumen is a complex organ that is critical for its host to convert low-quality feedstuffs into energy. The conversion of lignocellulosic biomass to volatile fatty acids and other end products is primarily driven by the rumen microbiome and its interaction with the host. Importantly, the rumen is demarcated into five distinct rumen sacs as a result of anatomical structure, resulting in variable physiology among the sacs. However, rumen nutritional and microbiome studies have historically focused on the bulk content or fluids sampled from single regions within the rumen. Examining the rumen microbiome from only one or two biogeographical regions is likely not sufficient to provide a comprehensive analysis of the rumen microbiome and its fermentative capacity. Rumen biogeography, digesta fraction, and microbial rumen–tissue association all impact the diversity and function of the entirety of the rumen microbiome. Therefore, this review discusses the importance of the rumen biographical regions and their contribution to microbiome variation.

Development and maintenance of healthy muscle fibers rely on the myogenic potential of satellite cells (SC), muscle stem cells that proliferate and differentiate to form myotubes. Satellite cells are indispensable for post-hatch muscle growth as well as muscle repair and regeneration when myofibers are damaged. Pectoralis major of young broiler chicks (5 day-olds) is a readily available source of SC, which can be used in vitro to elucidate cellular and molecular mechanisms responsible for muscle growth and regeneration in broilers. Here, we optimized a method for efficient isolation, purification, and differentiation of SC, from young broiler chicks. This procedure includes a simple method that allows SC to be purified from other muscle cell types that can impede the fidelity of follow-on experiments, particularly highly sensitive measures such as RNAseq. The methods for culturing and differentiating SC into multinucleated myotubes were also optimized by testing serum types, concentrations, and the effects of chicken embryo extract. Using the isolation procedure, a highly pure SC population (94.6 ± 2.11% Pax7 +) with high viability and yield was obtained, and their capacity to differentiate into myotubes was confirmed. Enrichment for SC and myogenic capacity were maintained through multiple passages and after cryopreservation. Analysis of gene expression over the first 48 h of differentiation confirmed that SC exhibited the expected molecular signature of myogenesis. Taken together, this method simplifies the ability to isolate and maintain a relatively pure population of SC with strong myogenic potential from young broiler chicks, and should support downstream applications for assessing the impact of nutrients, metabolites, and other physiological cues on muscle growth and development in broilers.