Poultry Science Journal
Volume:8 Issue: 2, Summer Autumn 2020

This study was conducted to determine the growth patterns of the Kuchi ecotype of chicken in Kenya. Data was obtained from intensively reared Kuchi birds at Indigenous Chicken Improvement Programme (INCIP) facility at Egerton University. Gompertz's nonlinear growth model was fitted to the Kuchi longitudinal growth data to predict the live body weight at various age points and the growth curve parameters. Growth rate and maturity parameters for all ages were calculated using growth curve parameters. The inflection parameter including age at inflection (TI), body weight at inflection (BWI), and growth rate at inflection (GI) was also calculated using the growth curve parameters. Males had significantly (P < 0.05) higher body weight from week 14 to week 32, and absolute growth rate from week 12 to week 28 of age. Males were significantly (P < 0.05) superior to counterpart females in asymptote (A), body weight at inflection (BWI), and weight gain at inflection (GI). Females attained puberty earlier than counterpart males and from week 8 of age, females were more mature than males with significant difference (P < 0.05) in both degree of maturity (U) and absolute maturity rate (AMR). From the results of this study, it is recommendable to rear Kuchi males and females separately from the age of inflection (week 12) when they experience significantly different growth rates. Optimum feeding of Kuchi should be done at age of week 8 to week 14 when its growth rate is highest thus high feed conversion efficiency and consequently high-profit margin. Kuchi chickens were found to have slower juvenile growth and may not be the best ecotype of chicken for quick production of tender meat among the indigenous chicken ecotype found in Kenya.

This study investigated the effect of reducing dietary metabolizable energy (ME) and crude protein (CP and amino acids) or decreasing only dietary CP [and amino acids, except first limiting amino acids (i.e. lysine, methionine+cystine, and threonine)] on mortality and performance of broilers raised in a farm 1,700 m above sea level. Two hundred and fifty-two Ross 308 male broiler chicks were distributed into 3 treatments with 6 replicates per each from 1 to 38 d of age. Dietary treatments were: control) a diet met or exceeded nutritional recommendations; DMC) a diet with the dilution of ME and CP (and amino acids), and DC) a diet with the dilution of CP (and amino acids, except lysine, methionine+cystine, and threonine). Mortality was higher in control compared to that of other treatments from 25 to 38 and 1 to 38 d of age. There was a higher relative weight of the right ventricle in control compared to that in DMC, and DC was being intermediate. During 1 to 38 d of age, control and DC improved average daily gain and adjusted feed conversion ratio compared to those of DMC. But in respect of the unadjusted feed conversion ratio and European poultry efficiency factor, DC improved these parameters compared to those of other treatments. In conclusion, decreasing CP content without any reductions in ME, lysine, methionine+cystine, and threonine concentration reduces mortality and enhances European poultry efficiency factor without any negative effects on feed efficiency or weight gain in broilers reared at a high-altitude area.

This experiment was conducted to study the effects of nucleotide supplementation on induced ascites and its effects on growth performance, blood metabolites, and expression of hypoxia-inducible factor 1α (HIF-1α) mRNA in Ross 308 broiler chickens. A total of 672 one-day-old Ross 308 broiler chicks were allocated to eight treatments with two levels of common salt in drinking water (0 and 2 g/lit) and four dietary supplemental levels of nucleotides (0, 0.5, 1, and 2 g/kg diet). Each treatment was included 7 replicates of 12 birds each. The experimental design was completely randomized in a factorial arrangement. In this study, 0.2% salt in drinking water induced ascites, decreased body weight (BW), and increased mortality, right ventricle (RV) weight as well as RV to total ventricles ratio (P < 0.05). Results showed that nucleotide levels of 0.05 and 0.1% significantly decreased RV weight and blood triiodothyronine (T3) concentration on 42 d. Interaction effects between salt and nucleotide supplement revealed that 0.1% nucleotide level in the salt group significantly reduced blood T3 concentration in comparison with non-nucleotide supplemented and normal water group. Feed intake, weight gain, feed conversion ratio, carcass characteristics, and the expression of HIF-1α mRNA in heart of broilers were not significantly affected by excess salt, nucleotide supplement, and their interaction. It was concluded that 0.5 g/kg dietary nucleotide supplementation decreased the ascites parameter of the RV/BW ratio in broiler chickens.

This experiment was conducted to investigate the effects of feed restriction and dietary supplementation of coenzyme Q10 (CoQ10) on growth performance, carcass characteristics, blood parameters, hormonal, immune responses, and intestinal microbiota. The completely randomized design experiment used a 2×2×3 factorial arrangement of treatments to provide two dietary restriction levels (10 and 20% less than the standard guide for Ross strain 308 broilers), two restriction durations (7 and 14 days), and three levels of CoQ10 (0, 20, and 40 mg/kg). In addition to the above-mentioned treatments, 3 other treatments were provided without feed restriction for each of the 3 levels CoQ10. Each of the fifteen treatments was replicated 4 times with each replicate containing 10 male birds. No differences were observed in weight gain among treatments. Feed conversion ratio decreased significantly when chicks had the highest duration (14 days) and intensity (20%) of feed restriction and fed all 3 levels of coQ10 as well as when had the mild duration (7 days) and intensity (10%) of feed restriction without coQ10 supplementation (P < 0.05). Heart weight and right ventricular to total ventricular ratio were not affected by feed restriction, but both total heart and right ventricular ratio decreased when CoQ10 was fed (P < 0.05). Blood and hormonal parameters were relatively unaffected by treatments although cortisol decreased with CoQ10 supplementation and CoQ10 at 40 mg/kg increased immune globulins M and G (P < 0.05). Under the conditions of this experiment, we conclude that supplementing CoQ10 can partially overcome the negative effects of feed restriction. Although the exact mechanism is unknown, CoQ10 appears to improve immune response and reduce subclinical ascites syndrome.

This 2 × 3 factorial experiment aimed to evaluate the single and interactive effects of feed form (pelleted, crumble and mash) and carbon tetrachloride (CCl4) intoxication on liver function, blood parameters, and certain external body dimensions in broiler chicken up to day 42 of age. The six experimental treatments were examined with a completely randomized block design in six replicates of 13 birds each using 468 10-day old female Arbor Acres (320±10g) chicks. For CCl4 intoxication, birds were intraperitoneally injected with 0.5, 0.5, and 0.75 mL/kg body weight CCl4 in olive oil at a ratio of 1: 1, v/v in days 14, 21, and 28 of age. Results indicated that feeding the pelleted diet increased daily weight gain (DWG), liver fat percentage (LFP), and improved feed conversion ratio compared with those received crumble and mash diets (P < 0.05). The broilers receiving the pelleted diet had a greater breast angle (BrG) than those feeding with the mash diet (P < 0.05). Exposure to CCl4 decreased breast width (BrW), breast girth (BrG), and BrA of the treated birds (P < 0.01). The best multivariate linear model for prediction of liver fat percentage achieved by the Forward modeling approach in SAS involving serum TC, LDL TP, TBIL, LDH, BrA, and ShL with R2=0.3011. It was concluded that feeding diets in pelleted form may cause a greater performance loss and liver dysfunction when broiler chickens are fed with contaminated feed resources. Moreover, prediction of LFP using multivariate linear models based on blood constituents and external body measurements could not be convincing as for no model R2 exceeds 0.31 likely due to the lack of strong correlation between LFP and the considered predictors.

To investigate the effects of newly introduced probiotic, prebiotic, and synbiotic, 1080 d-old broiler chickens were used in a completely randomized design with six treatments and six replicates of 30 birds each. Dietary treatments were: basal diet (control), basal diet plus 500 g of probiotic/ton (Probiotic-500), basal diet plus 500 g and 300 g of probiotic/ton during days 0-24 and 25-42 of age, respectively (Probiotic-500-300), basal diet plus 300 g of probiotic/ton (Probiotic-300), basal diet plus 1 kg of prebiotic/ton (Prebiotic), basal diet plus 1 kg of synbiotic/ton (Synbiotic). Average daily weight gain and feed conversion ratio were only affected by dietary treatments during the starter period; the lowest average daily weight gain and the highest feed conversion ratio were recorded for the control treatments compared to the others. The antibodies titers (total, IgG, and IgA) against sheep red blood cells, and Newcastle and Influenza viruses were significantly (P < 0.05) increased by feeding diets containing all experimental additives compared with the control diet. The pH of the ileum decreased (P < 0.05) by using probiotic, prebiotic, and synbiotic in the diets. The highest number of lactobacillus and E. coli populations was observed in birds fed synbiotic and control diet, respectively. The height of villus in the jejunum and its ratio to crypt depth was higher in birds fed a symbiotic diet compared to birds fed probiotic or control diets (P < 0.05). Furthermore, the cecum concentration of short-chain fatty acids was greater in chickens fed diets containing probiotic, prebiotic, or synbiotic than the control chickens (P < 0.05). In conclusion, although dietary supplementation with probiotic, prebiotic, and synbiotic had no positive effect on growth performance parameters of broiler chickens, the use of these products could exert promising effects on poultry health.

This sudy was conducted to evaluate the effects of sugar beet pulp and potato peels, as agro-industrial byproducts, with and without enzyme supplementation on nutrient digestibility, gut morphology, and meat quality of broiler chickens. Broiler chicks (n= 150) were randomly divided into five groups, each with 30 birds. Chicks in the first group were fed on the control diet. Birds in second and third groups were given diets containing potato peels and sugar beet pulp at a level of 15.0% and 7.5%, respectively, while those in the fourth and fifth groups were offered the same diets but with adding an enzyme mixture. Diets containing potato peels or sugar beet pulp did not (P > 0.05) affect the digestibility of ether extract, crude fiber, or crude protein. Feeding of potato peels did not (P > 0.05) affect the intestinal morphology during the starter or grower period. However, sugar beet pulp reduced (P < 0.05) the villus height and villus height/crypt depth ratio during the starter period, but without any effect at the grower period. Generally, feeding of potato peels or sugar beet pulp did not (P > 0.05) affect the physicochemical and sensory characteristics of the breast or thigh muscles. Supplementation of the enzyme to the diets increased (P < 0.05) digestibility of nutrients and improve the development of the small intestine. Also, the dietary enzyme inclusion increased (P < 0.05) the crude protein content and reducing the ether extract of the meat as well as increasing its water holding capacity with a reduction of the cooking loss rate. In conclusion, adding the enzyme to the diets containing potato peels or sugar beet pulp can enhance the digestion and absorption of nutrients as well as improve the meat quality of the broilers’ carcass. Also, the tested byproducts can help in solving the problem of low availability and rising costs of traditional poultry feeds.

The study was conducted to determine the apparent and standardized ileal digestibility (AID and SID) of phosphorus (P) in plant origin feedstuffs of corn distiller’s dried grains with solubles (corn DDGS), wheat bran (WB), wheat grain (WG), wheat middling (WM),soybean meal (SBM), canola meal (CNM), cottonseed meal (CSM), and peanut meal (PM), fed to total 612 male arbor acres broilers with or without microbial phytase. A 23 day-old birds with initial body weight (BW) of  939±8.89g were randomly allocated to a factorial 2 × 8 arrangement with a randomized complete block design of sixteen dietary treatments and one P-free diet, with six replicates (cage) and six birds/cage. A purified phosphorus-free (P-free) diet was also prepared to determined endogenous P loss (EPL). The ileal digesta were collected from euthanized birds and analyzed. The study results indicated that the SID of P in WB (38.46%), PM (37.98%), WG (36.90%), and WM (35.69%) was significantly lower (P < 0.001) than SBM (52.01%), corn DDGS (49.41%), CNM (47.02%), and CSM (46.09%) based diets. The Addition of microbial phytase to SBM and WM improved the SID of P by more than 40%, while the others improved by about 34.80%, which is from 31.55% in CNM to 37.77% in CSM. The least improvement was recorded in corn DDGS (5.12%). The feedstuffs ileal digestible P equivalent value of 1000 FTU/kg phytase was ranged from 0.2g to 1.6g. The ileal EPL of the current study was determined to be 46.28 mg/kg DMI. In conclusion, the application of microbial phytase and formulation of plant origin broiler diets based on SID of P can reasonably help to utilize phosphorus resources for reducing feed costs and minimize environmental pollution.

The primary aim of this study was to assay the influence of pellet and mash diets supplemented with different levels of mesquite fruit on performance, energy and protein efficiency ratio, carcass characteristics, and intestinal morphology of broiler chickens. In this study, a total of 560 one-day-old (mixed sex) Ross 308 were distributed in a completely randomized design with 7 treatments, 4 replicates, and 20 chicks per replicate. Seven iso-caloric and iso-nitrogenous diets including a control diet (mash form without mesquite fruit), and pelleted and mash diets, consisting of three levels of mesquite fruit (3, 6, and 9%) were adjusted. The results exhibited that mesquite fruit contained a high percentage of dietary fiber. The results also showed that pelleted and mash diets containing different levels of mesquite caused a significant difference in feed intake, body weight gain, and feed conversion ratio in starter and grower periods. At the finisher period, there was a significant difference between the experimental treatments in terms of feed intake and body weight gain, but there was no significant difference in feed conversion ratio. Experimental treatments also caused a significant difference in energy and protein efficiency ratio in the starter and grower periods. Dietary treatments also exhibited a significant difference in the relative weight of breast and intestine, but no effect was found on carcass yield and relative weight of other internal organs. The findings revealed that pelleted and mash diets containing different levels of mesquite fruit did not show significant differences in morphological traits of the intestine. Taken together, our results suggested that, the use of mesquite fruit in pelleted diets can have positive effects on the performance of broilers.

Effects of dietary inclusion of cumin (CUM) and black cumin (BCUM) powders were investigated on the performance, nutrient digestibility, lipid deposition, and immunocompetence of broiler chickens in a rearing period of 42 days. A total number of 240 male ROSS 308 day-old chicks were randomly allocated to six dietary treatments with four replicates. Dietary treatments consisted of a basal diet as control, control + 10 ppm avilamycin, control + 0.25% CUM, control + 0.75% CUM, control + 0.25% BCUM, and control + 0.75% BCUM. Feed intake, body weight gain (BWG), and feed conversion ratio (FCR) were recorded weekly. Total tract apparent digestibility (TTAD) of crude protein (CP) and ether extract (EE) were measured on day 21. Sheep red blood cells (SRBC) and cutaneous basophil hypersensitivity (CBH) tests were used to evaluate immune responses. On day 42, two chickens from each replicate were selected, bled, euthanized, and carcass, abdominal fat pad, and internal organs were weighted. CUM and also avilamycin improved BWG during the grower and whole period of the experiment. Also, FCR was improved by CUM (0.75%) as well as avilamycin compared to control. Also, CUM (0.75%) decreased serum total cholesterol and LDL, and increased antiSRBC response compared to control. Supplementing the diet with 0.75% CUM also decreased abdominal fat pad percentage compared to other groups. There was an improvement in TTAD of CP and EE with dietary inclusion of CUM (0.75%) as well as avilamycin, compared to control. However, BCUM did not changed the all measured parameters but increased FCR and decreased (0.75% BCUM) BWG and TTAD of CP compared to control. This study indicated growth-promoting, immunostimulatory, and hypolipidemic effects for cumin as a phytogenic feed additive. Then, it may act as an alternative for in-feed antibiotics in broiler nutrition.

The current study evaluated the effects of feeding a phytogenic substance, Macleaya cordata alkaloid extract (MCAE), on the growth performance and protein digestibility of broiler chickens fed two dietary concentrations of protein. A total of 560, one-day-old male broiler chicks (initial body weight = 39.9 ± 0.1) were randomly assigned to eight dietary treatments with five replicates (14 broiler chickens per replicate) in a 2 × 4 factorial arrangement including two concentrations of dietary crude protein (100 and 95% of established requirements; control and low-protein diets, respectively) and four inclusion rates of MCAE (0, 180, 360, and 540 mg/kg diet). Crude protein (CP) and MCAE interactions occurred on the apparent ileal digestibility of CP (P = 0.05), organic matter (P = 0.01), and ash (P = 0.01) at d 35. However, no interaction between CP and MCAE occurred for body weight, average daily gain, and the feed conversion ratio. Dietary MCAE supplementation increased body weight (P = 0.01) at d 35, average daily feed intake (P = 0.04), and average daily gain (P = 0.02) from d 1 to 35 of the broiler chickens linearly. Greater carcass yield and reduced abdominal fat were observed with a higher level of dietary protein intake (P = 0.01). Dietary supplementation with MCAE also reduced the relative weight of the ceca linearly (P = 0.01) without affecting carcass yield at d 35. Dietary treatments had no effects on plasma free Met, Thr, and Gly concentrations at d 35 and serum uric acid and creatinine concentrations at d 15 and 35. In summary, these results indicated that dietary supplementation with MCAE may improve body weight and average daily gain of broiler chickens at both dietary protein levels, by enhancing apparent ileal digestibility of dietary CP and organic matter, as well as by increasing feed intake.

To investigate the effects of dietary supplementation with industrial vinegar (IV) and waste date vinegar (WDV) on growth performance, intestinal morphology, and immune response of broilers, five hundred Ross 308 chickens were randomly divided into 50 cages in a 42-day breeding period. The experiment consisted of ten treatments with five replications in each treatment including; control 1 (standard feed without  WDV or IV), control 2 (control 1 + 2% water into the feed), 1, 2, and 3% of WDV and 2% industrial vinegar (IV) into the feed and 0.5, 1, and 1.5% of WDV and 1% industrial vinegar (IV) into the water. One chicken from each replicate was slaughtered on days 24 and 42 to investigate gastrointestinal tissue growth as well as intestinal morphology. The results showed that growth performance was not affected by treatments in any period. The height and width of the villus in the treatments containing 1% of WDV into the water and 2% of WDV into the feed increased with time compared to the control treatments. On day 42 of the experiment, the crypt depth was also higher in the treatment containing 1% of WDV into the feed compared to the other treatments. The ileal coliforms were also affected by WDV addition into the feed at 42 days of age compared to other groups (P < 0.05). The highest amount of IgM and IgG were found to levels of 2% and 1% of WDV into the diet, respectively (P < 0.05). However, SRBC, ND titter was not affected by treatments. Also, no difference was found between industrial vinegar in water or feed in most of the studied parameters. The results of this study showed that supplementation of the diet with WDV had a positive effect on intestinal morphology and immune system of broilers compared to industrial vinegar.