Effect of dietary crude protein degradability and corn processing on lactation performance and milk protein composition and stability.

The present study aimed to evaluate the effect of crude protein degradability and corn processing on lactation performance, milk protein composition, milk ethanol stability (MES), heat coagulation time (HCT) at 140°C, and the efficiency of N utilization for dairy cows. Twenty Holstein cows with an average of 162 ± 70 d in milk, 666 ± 7 kg of body weight, and 36 ± 7.8 kg/d of milk yield (MY) were distributed in a Latin square design with 5 contemporaneous balanced squares, 4 periods of 21 d, and 4 treatments (factorial arrangement 2 × 2). Treatment factor 1 was corn processing [ground (GC) or steam-flaked corn (SFC)] and factor 2 was crude protein (CP) degradability (high = 10.7% rumen-degradable protein and 5.1% rumen-undegradable protein; low = 9.5% rumen-degradable protein and 6.3% rumen-undegradable protein; dry matter basis). A significant interaction was observed between CP degradability and corn processing on dry matter intake (DMI). When cows were fed GC with low CP degradability, DMI increased by 1.24 kg/d compared with cows fed GC with high CP degradability; however, CP degradability did not change DMI when cows were fed SFC. Similar interactions were observed for MY, HCT, and lactose content. When cows were fed GC diets, high CP degradability reduced MY by 2.3 kg/d, as well as HCT and lactose content, compared with low CP degradability. However, no effect of CP degradability was observed on those variables when cows were fed SFC diets. The SFC diets increased dry matter and starch total-tract digestibility and reduced ß-casein (CN) content (% total milk protein) compared with GC diets. Cows fed low-CP degradability diets had higher glycosylated κ-CN content (% total κ-CN) and MES, as well as milk protein content, 3.5% fat-corrected milk, and efficiency of N for milk production, than cows fed high-CP degradability diets. Therefore, GC and high-CP degradability diets reduced milk production and protein stability. Overall, low CP degradability increased the efficiency of dietary N utilization and MES, probably due to changes in casein micelle composition, as CP degradability or corn processing did not change the milk concentration of ionic calcium. The GC diets increased ß-CN content, which could contribute to reducing HTC when cows were fed GC and high-CP degradability diets.

Gingival crevicular fluid levels of human beta-defensin 1 in individuals with and without chronic periodontitis.

BACKGROUND AND OBJECTIVE: Human beta-defensins (hBDs) contribute to innate immunity antimicrobial activity. They are also effective in the adaptive immune response and may play a crucial role in the susceptibility to diseases of the oral cavity. This study aimed to evaluate the levels of hBD-1 in the gingival crevicular fluid of individuals with and without chronic periodontitis. MATERIAL AND METHODS: Twenty periodontally healthy individuals (H) and 20 individuals with chronic periodontitis were recruited. Gingival crevicular fluid samples were collected from: healthy sites (Hh) from periodontally healthy individuals; and healthy sites (Ph), sites with gingivitis (Pg), and sites with periodontitis (Pp) from individuals with periodontitis. The levels of hBD-1 (pg/mL) were measured using enzyme-linked immunosorbent assay. Comparisons of hBD-1 between individuals (H and chronic periodontitis) and among sites (Hh, Ph, Pg, Pp) were performed through hierarchical linear modeling. RESULTS: Gingival crevicular fluid levels of hBD-1 were: Hh = 229.52 ± 138.96 (median 199.26), Ph = 53.88 ± 58.17 (median 35.75), Pg = 57.11 ± 40.18 (median 39.90) and Pp = 55.31 ± 37.28 (median 54.19). No influence of site diagnosis (level 1; health/gingivitis/periodontitis) was observed; however, individual diagnosis (level 2; health/periodontitis) influenced the levels of hBD-1 (P < .001). CONCLUSION: Periodontally healthy individuals showed higher gingival crevicular fluid levels of hBD-1 when compared to individuals with chronic periodontitis. This suggests a potential protective role of hBD-1 in the susceptibility to chronic periodontitis.

Dog skin parasite load, TLR-2, IL-10 and TNF-α expression and infectiousness.

Visceral leishmaniosis is a zoonotic disease that is transmitted by Lutzomyia longipalpis sandflies. Dogs are the main peri-urban reservoir of the disease, and progression of canine leishmaniosis is dependent on the type of immune response elaborated against the parasite. Type 1 immunity is characterized by effective cellular response, with production of pro-inflammatory cytokines such as tumour necrosis factor alpha (TNF-α). In contrast, Type 2 immunity is predominantly humoral, associated with progression of the disease and mediated by anti-inflammatory cytokines such as interleukin 10 (IL-10). Although seemly important in the dynamics of leishmaniosis, other gene products such as toll-like receptor 2 (TRL-2) and inducible nitric oxide synthase (iNOS) exert unclear roles in the determination of the type of immune response. Given that the dog skin serves as a micro-environment for the multiplication of Leishmania spp., we investigated the parasite load and the expression of TLR-2, iNOS, IL-10 and TNF-α in the skin of 29 infected and 8 control dogs. We found that increased parasite load leads to upregulation of TLR-2, IL-10 and TNF-α, indicating that abundance of these transcripts is associated with infection. We also performed a xenodiagnosis to demonstrate that increased parasitism is a risk factor for infectiousness to sandflies.