Effect of different feed restriction programs on the performance and reproductive traits of broiler breeders.

The current experiment evaluated the effect of different feed restriction programs applied during rearing on the performance and reproductive traits of broiler breeder pullets reared on floor pens, isolating the birds' weight effect from the analysis. At 4 wk of age, 1,400 breeder pullets were distributed in a completely randomized design with 4 treatments: daily restriction (DAILY-every day feeding), skip-a-day restriction (SKIP-every other day feeding), 4/3 restriction (4/3-4 days feeding and 3 nonconsecutive fasting days) and 5/2 restriction (5/2-5 days feeding and 2 nonconsecutive fasting days), and 8 replicates. At 11, 18, 25, 32, and 39 wk of age, body weight, feed intake, feed conversion ratio, carcass composition, organs relative weight (liver, fat, oviduct, and ovary stroma), egg production, and egg weight were accessed. At 32 and 39 wk, 12 eggs by experimental unit were collected and incubated to determine hatchability and fertility parameters. Body weight, carcass EE, and FCR were higher for SKIP birds when compared to other feed restriction programs. SKIP birds also showed the lowest number of eggs per bird (NEB) and % of egg production when compared to 4/3 feeding schedule, which provided higher values. Feed conversion ratio per egg mass (FCEM) was also higher in 4/3 schedule in relation to SKIP birds. In regard to incubation parameters, 5/2 treatment showed higher values for hatchability (HAT) and fertility (FERT), similar to results of 4/3 and DAILY treatments, while SKIP birds showed the lowest. In conclusion, 4/3 and 5/2 feeding programs showed best results and should be used by broiler breeder producers to control pullets' body weight. Therefore, the higher number of eggs produced with less feed and statistically not different fertility and hatchability between programs obtained in this study suggest the 4/3 program could be more efficient than 5/2 program. Body weight'|'s effect isolation was important to analyze the effect of feed restriction program per se, and should be applied in future approaches.

Interference of age and supplementation of direct-fed microbial and essential oil in the activity of digestive enzymes and expression of genes related to transport and digestion of carbohydrates and proteins in the small intestine of broilers.

The objectives of this study were to describe alterations that age and dietary inclusion of direct-fed microbial (DFM) Bacillus subtilis (BS) and a specific essential oil (EO) blend (carvacrol, cinnamaldehyde, cineol, and pepper extract) causes in the activity of digestive enzymes (maltase: MALT; aminopeptidase-N: APN; intestinal alkaline phosphate: IAP) and expression patterns of genes related to transport (oligopeptide transporter gene: SLC15A1; Na+-dependent glucose and galactose transporter gene: SLC5A1; Na+-independent glucose, galactose, and fructose transporter gene: SLC2A2; ATPase, Na+/K+ transporting gene: ATP1A1) and digestion (aminopeptidase-N gene: ANPEP; maltase-glucoamylase gene: MGAM; Sucrase-isomaltase gene: SI) of carbohydrates and proteins in the small intestine of broilers. Also, the objective was to analyze if growth performance of broilers is affected by supplementation (BS and EO blend). Day-old male broiler chicks (n = 1,320) were assigned to 5 treatments. Diets included a basal diet (BD) as a negative control (CON); experimental diets were BD + BS; BD + BS + EO; BD + EO; BD + antibiotic growth promoter (AGP) avilamycin was the positive control. Performance was evaluated between 1 to 42 d. Transcript abundance of transport-related genes and digestion-related genes were assayed by RT-qPCR and determined at d 7, 21, and 42. MALT-, APN-, and IAP-specific activities were determined at d 7, 21, and 42. Broilers fed BS had greater SLC15A1 mRNA abundance compared to CON, while EO and AGP were related to higher activities of IAP and APN. Analysis over time revealed higher abundance of MGAM, SLC2A2, SLC15A1, SLC5A1 and SI mRNA at d 42 when compared to d 7. Activity of IAP decreased after d 7 and activity of MALT increased with age. The current study suggests that age had effect over carbohydrate and protein transport and carbohydrate digestion. The supplementation of BS DFM hade evident effect over protein transport and that the use of EO in the diet enhanced the activities of carbohydrate and protein digestion, reflecting improvement in digestive and transport physiology of birds. Changes performed by BS DFM and EO did not favor performance.

Analysis of the intestinal bacterial microbiota in maize- or sorghum-fed broiler chickens using real-time PCR.

1. An experiment was conducted to study the effect of two different diets on zootechnical performance and the major bacterial groups in association with the host mucosa and dispersed in the lumen contents of the small intestine of broiler chickens. 2. The two experimental diets were maize or sorghum-based. In addition to the total bacteria, bacterial groups belonging to the Enterobacteriaceae (Enterococcus and Lactobacillus) were quantified by real-time PCR. 3. There were no differences in body weight gain and feed intake, but feed conversion ratio increased for sorghum-fed broilers at 21 and 42 d of age. 4. The Enterococcus group decreased in all gut segments from 7 to 42 d, while the Lactobacillus group increased in both ecosystems. In the ileal mucosa, the enterobacterial counts decreased from 7 to 42 d in the maize-based diet, but remained stable in the sorghum-based diet. 5. The results shed light on the spatial and temporal distribution of bacterial groups that play important physiological roles in the small intestine of chickens. Specifically, the increased Enterobacteria population in the ileum is consistent with the relatively poor feed conversion in sorghum-fed broilers.

Fuzzy modeling to predict chicken egg hatchability in commercial hatchery.

Experimental studies have shown that hatching rate depends, among other factors, on the main physical characteristics of the eggs. The physical parameters used in our work were egg weight, eggshell thickness, egg sphericity, and yolk per albumen ratio. The relationships of these parameters in the incubation process were modeled by Fuzzy logic. The rules of the Fuzzy modeling were based on the analysis of the physical characteristics of the hatching eggs and the respective hatching rate using a commercial hatchery by applying a trapezoidal membership function into the modeling process. The implementations were performed in software. Aiming to compare the Fuzzy with a statistical modeling, the same data obtained in the commercial hatchery were analyzed using multiple linear regression. The estimated parameters of multiple linear regressions were based on a backward selection procedure. The results showed that the determination coefficient and the mean square error were higher using the Fuzzy method when compared with the statistical modeling. Furthermore, the predicted hatchability rates by Fuzzy Logic agreed with hatching rates obtained in the commercial hatchery.