Evaluating performance, intestinal lesions, and immunity related genes in heritage and modern broiler breeds during a necrotic enteritis challenge.

In this comparative study, the differential responses of heritage (ACRB; Athens Canadian Random Bred) and modern (Cobb) broilers to a necrotic enteritis (NE) challenge were evaluated. The design was a 2×2 factorial with breed (ACRB and Cobb) and challenge (non-challenged and NE-challenged) as main factors. On day (d) of hatch, 96 male chicks (48 ACRB and 48 Cobb) were allocated to 4 experimental groups with 8 replicate cages and 3 birds/cage. On d 14, birds in the NE-challenged groups were orally gavaged with 3,000 Eimeria maxima sporulated oocysts followed by 2 doses of ∼1×108 CFU of Clostridium perfringens on d 19 and 20. On d 21, 2 birds/cage were necropsied to score NE lesions, and spleen and cecal tonsils (CT) samples were collected from 1 bird/cage for assessing mRNA abundance. Challenged ACRB birds exhibited reduced growth performance and relative growth performance compared to challenged Cobb birds. There was no significant interaction between breed and challenge during the challenge period (d 14-21) for mortality. However, there was a challenge main effect (P ≤ 0.05) on mortality as manifested by greater NE-associated mortality compared to non-challenged birds. No significant breed × challenge interaction or breed main effect on lesion scores were observed in the duodenum, jejunum, and ileum. NE-challenged Cobb birds exhibited greater mRNA abundance of IL-18, TNFα, TLR1.2, TLR2.1, CCR5, CCR6, CCL20, and AvBD1 in CT compared to NE challenged ACRB birds. There was a significant breed × challenge interaction effect on mRNA abundance of IL-10, AvBD13, NK-Lysin, and LEAP2 in the spleen. Moreover, a main effect of breed was observed in IL-1ß, IL-18, TNFα, TLR2.1, CCR5, CCL20, and NK-Lysin where ACRB birds had higher mRNA abundance than Cobb birds (P ≤ 0.05). The observed differences in performance, pathology, and mRNA abundance between ACRB and Cobb broilers during the NE challenge highlight the distinct immune response profiles of heritage and modern breeds, emphasizing the need for breed-specific nutritional, managerial, and genetic selection programs for modulating immune responses during enteric disease challenges.

Inclusion of Quillaja Saponin Clarity Q Manages Growth Performance, Immune Response, and Nutrient Transport of Broilers during Subclinical Necrotic Enteritis.

Necrotic enteritis (NE) is an intestinal disease that results in poor performance, inefficient nutrient absorption, and has a devastating economic impact on poultry production. This study evaluated the effects of a saponin-based product (Clarity Q, CQ) during an NE challenge. A total of 1200 male chicks were randomly assigned to four dietary treatments (10 pens/treatment; 30 birds/pen): treatment 1 (NC), a non-medicated corn-soybean basal diet; treatment 2 (PC), NC + 50 g/metric ton (MT) of bacitracin methylene disalicylate (BMD); and treatments 3 (CQ15) and 4 (CQ30), NC + 15 and 30 g/MT, respectively. On the day (d) of placement, birds were challenged by a coccidia vaccine to induce NE. On d 8, 14, 28, and 42, performance parameters were measured. On d 8, three birds/pen were necropsied for NE lesions. On d 8 and d 14, jejunum samples from one bird/pen were collected for mRNA abundance of tight junction proteins and nutrient transporter genes. Data were analyzed in JMP (JMP Pro, 16), and significance (p ≤ 0.05) between treatments was identified by Fisher's least significant difference (LSD) test. Compared to PC and NC, CQ15 had higher average daily gain (ADG), while CQ30 had lower average daily feed intake (ADFI) and feed conversion ratio (FCR). NE lesions in the duodenum were lower in CQ15 compared to all other treatments. On d 8, mRNA abundance of CLDN1, CLDN5, AMPK, PepT2, GLUT2, and EAAT3 were significantly greater in CQ30 (p < 0.05) compared to both PC and NC. On d 14, mRNA abundance of ZO2 and PepT2 was significantly lower in PC when compared to all treatments, while that of ANXA1, JAM3, and GLUT5 was comparable to CQ15. In summary, adding Clarity Q to broiler diets has the potential to alleviate adverse effects caused by this enteric disease by improving performance, reducing intestinal lesions, and positively modulating the mRNA abundance of various tight junction proteins and key nutrient transporters during peak NE infection.

Spray-Dried Plasma Promotes Broiler Chick Growth by Enhancing Immune Surveillance.

Spray-dried plasma (SDP) contain a variety of functional proteins that play an immunomodulatory role. To evaluate the potential of SDP to stimulate the immune system, day-old Ross 708 male broiler chicks (200) were allocated randomly to five dietary treatments. Treatment 1 (CX) comprised chicks fed basal unmedicated corn-soybean meal (SBM) without the addition of SDP. Treatment 2 (MX) includes chicks fed unmedicated corn-SBM basal containing Bacitracin methylene disalicylate (BMD) at 0.055 g/kg diet. Treatments 3 (SDP1), 4 (SDP2), and 5 (SDP3) contained chicks given unmedicated corn-SBM basal, into which SDP was included at 10, 20, and 30 g/kg diet, respectively. On d 7, 14, and 21, chicks' body weight and FCR were calculated. Additionally, leucocyte counts, oxidative status, and IgY concentrations were determined in blood. On d 23, fecal populations of selected indicator bacteria species were determined. Results showed that FCR for SP3 was superior (p < 0.05) to other treatments. Likewise, heterophil numbers decreased in MX and SDP treatments compared to CX. Circulating IgY concentration was higher for SDP dietary treatments (p < 0.05) compared to MX. In conclusion, dietary SDP at 30 g/kg enhanced immune surveillance by increasing circulating IgY levels, maintaining a normal oxidative state, and increasing gut Bifidobacteria, thereby improving chick growth performance.