The effects of feed restriction and ambient temperature on growth and ascites mortality of broilers reared at high altitude

Data Analytics of Broiler Growth Dynamics and Feed Conversion Ratio of Broilers Raised to 35 d under Commercial Tropical Conditions

Data collection is standard in commercial broiler production; however, growth modeling is still a challenge since this data often lacks an inflection point. This study evaluated body weight (BW) dynamics, feed intake, BW gain, feed conversion ratio (FCR), and mortality of broiler flocks reared under commercial tropical conditions with controlled feeding to optimize FCR. The data analyzed included performance records of 1347 male and 1353 female Ross 308 AP broiler flocks with a total of 95.4 million chickens housed from 2018 to 2020. Decision trees determined high- and low-feed-efficiency groups using FCR at 35 d. Logistic, Gompertz-Laird, and von Bertalanffy growth models were fitted with weekly BW data for each flock within performance groups. The logistic model indicated more accurate estimates with biological meaning. The high-efficiency males and females (p < 0.001) were offered less feed than the low-efficiency group and were consistently more efficient. In conclusion, greater feeding control between the second and the fourth week of age, followed by higher feed allowance during the last week, was associated with better feed efficiency at 35 d in males and females. Additionally, models demonstrated that a reduced growth rate resulted in heavier chickens at 35 d with better feed efficiency and greater BW gain.

Changes in the Expression of MIF and Other Key Enzymes of Energy Metabolism in the Myocardia of Broiler Chickens with Ascites Syndrome

Ascites syndrome (AS) is a metabolic disease observed mainly in fast-growing broilers. The heart is one of the most important target organs of the disease. The goal of this study was to evaluate the metabolic function of the right ventricles in clinical ascitic broilers. HE staining was performed to observe histopathological changes in the right ventricle of the heart, while Western blotting was used to detect the protein expression levels of macrophage migration inhibitory factor (MIF) and phosphorylated AMP-activated protein kinase (p-AMPK), as well as other key enzymes of energy metabolic pathways (i.e., glycolytic pathway: HK2, PFK1, PFK2, and PKM2; the tricarboxylic acid cycle (TCA cycle) pathway: OGDH, IDH2, and CS; and the fatty acid oxidation pathway: CPT-1A and ACC) in myocardial tissue. The histopathological examination of the myocardia of ascitic broilers revealed disoriented myocardial cells in the myofibril structure and a large number of blood cells deposited in the intermyofibrillar vessels, suggesting right heart failure in ascitic broilers. The Western blotting analysis demonstrated significantly increased levels of MIF and p-AMPK in the myocardia of ascitic broilers compared to those of the control group (p < 0.05). Additionally, the protein expression of key enzymes was dramatically increased in the glycolytic and fatty acid oxidation pathways, while the protein expression of key enzymes in the TCA cycle pathway was decreased in the ascitic broiler group. These findings suggest enhanced glycolysis and fatty acid oxidation metabolism, and a diminished TCA cycle, in the myocardia of broiler chickens with ascites syndrome.

Comparison of the frequency of patho-anatomic findings in laying hens with findings in broiler chickens and turkeys detected during post-mortem veterinary inspection

We have investigated the health condition of laying hens on the basis of patho-anatomic findings obtained during the veterinary inspection after slaughter. To assess the severity of the health condition of laying hens, we compared the incidence of findings with the findings in broiler chickens and turkeys. In the period from 2010 to 2017, 17,346,183 laying hens, 887,994,167 broiler chickens, and 919,843 turkeys were transported from Czech farms to slaughterhouses in the Czech Republic. The competent veterinary authority in the Czech Republic (the State Veterinary Administration) carried out a veterinary inspection of these birds slaughtered in the slaughterhouse and recorded the patho-anatomic findings. From the recorded data, the number of patho-anatomic findings (intravital origin) of the organs and parts of the bodies (liver, intestines, lungs, heart, spleen, genital tract, urinary system, CNS, skin, head, body, limbs, and whole animal) were analysed. We found increased patho-anatomic findings in the liver (26.76%) and limbs (6.03%) in hens, and also high numbers of findings in the category of total findings (1.57%) were detected. In liver findings, chronic findings (22.09%) were prevailing over the acute findings (4.67%), compared to broiler chickens (chronic 0.04%, acute 0.03%) and turkeys (chronic 1.90%, acute 0.00%). The differences between hens, broilers, and turkeys were significant (P < 0.001). The incidence of traumatic, chronic, and acute findings in hens (3.88%, 1.71%, and 0.44%, respectively) was higher (P < 0.001) in the case of the legs, compared with broiler chickens (0.02%, 0.08%, and 0.02%, respectively) and turkeys (0.27%, 0.23%, and 0.05%, respectively). The results show that the health condition of laying hens is significantly worse than in case of broiler chickens and turkeys, especially in the impact on the liver due to the likely effect of nutrition not corresponding to the intensity of the production of laying hens, and the impact on the limbs due in particular to traumatic changes caused by inappropriate transport handling and inadequate conditions (especially cage housing) of laying hens.

Effects of oxygen levels and a Lactobacillus plantarum strain on mortality and immune response of chickens at high altitude

Chickens reared in high altitude regions suffer from a high mortality, possibly due to poor immune responses induced by hypoxia. This experiment was conducted to evaluate whether increasing the oxygen level or administration of a probiotic could improve mortality and immune response of chickens at high altitude (2,986 m above the sea level). One-d-old chickens were randomly allocated to 1 of 6 treatments in a 2 × 3 factorial arrangement. The first factor was the oxygen level (low and high), while the second factor was the diet (basal diet, basal diet containing aureomycin, and basal diet plus L. plantarum). Increasing the oxygen level significantly reduced the mortality and improved immune responses. The levels of IgA, IgG, IL-10 and anti-BSA antibodies were significantly higher, while IL-1β, LITAF were significantly lower in chickens reared in the high-oxygen room. In the low-oxygen room, L. plantarum significantly decreased the mortality of chickens compared with the other 2 groups. Moreover, L. plantarum significantly increased the levels of IgA, anti-BSA antibodies, IL-10 and decreased IL-1β, LITAF compared with the control group. These results demonstrated that increasing oxygen level or administration of L. plantarum can improve health status of chickens in high altitude regions.

Use of supplemental dietary coenzyme Q10 to improve testicular function and fertilization capacity in aged broiler breeder roosters

In numerous studies it has been suggested that targeting mitochondria with specific compounds could efficiently inhibit various conditions associated with oxidative stress. The treatment of aged roosters with compounds such as coenzyme Q10 (CoQ10), may improve their reproductive performance by providing protection from oxidative stress. Therefore, this study was performed to assess the effect of supplemental dietary CoQ10 on the testicular function and fertility of aged broiler breeder roosters. A total of 36 roosters)47 weeks of age) were randomly divided into dietary treatments containing either 0, 300 or 600 mg CoQ10/kg diet. Three birds were allocated to each of four replicate groups in each dietary treatment. Between 47 and 54 weeks of age, ejaculates were obtained weekly from the three roosters in each replicate group. Samples in a replicate were pooled and analyzed as a single sample. Between 51 and 54 weeks of age, seminal plasma total antioxidant capacity (TAC), alanine amino transferase (ALAT) and aspartate amino transferase (ASAT) levels were assessed. Fertility, hatchability, and sperm penetration (SP) rates were likewise evaluated. Seminal volume, sperm concentration, sperm plasma membrane functionality, sperm plasma membrane integrity, seminiferous tubule diameter and seminiferous epithelium thickness exhibited quadratic increases in response to increasing levels of dietary CoQ10. Respectively, the 429.19, 433.33, 464.50, 613.50, 392.78 and 447.99 mg/kg dietary concentrations of CoQ10 provided the best results for each of the aforementioned variables. Also, other seminal traits, as well as testosterone concentration, fertility, and SP rates, displayed linear increases in response to the increasing levels of CoQ10. Dietary supplementation of CoQ10 linearly decreased seminal plasma ALAT and ASAT and linearly increased seminal plasma TAC. In conclusion, CoQ10 supplementation in the diet (a minimum of 300 mg CoQ10/kg diet) has the potential to improve the reproductive performance of aged broiler breeder roosters.

A Trial Diagnosis of Ascites Syndrome in Broiler Chickens

BACKGROUND

Ascites syndrome is currently a serious disease issue for the global chicken industry. Ascites syndrome is a metabolic disorder frequently found in fast growing broilers including abdominal distention and standing fluid collection in chicken abdomen. It is one of the most common nutrition metabolic disorders.

MATERIALS AND METHODS

In this study, the clinical diagnosis technology of broiler ascites symptoms mainly included the trial inquiry of feeders and administrators, local observation, detection of farm gas and faeces and pathological autopsy.

RESULTS

The study investigated the case of broiler ascites syndrome of local commercial broiler chickens at the age of 4-5 weeks to reduce outburst of ascites syndrome in broiler chickens. Through the trial clinical diagnosis of broiler ascites symptoms and pathological autopsy and observation, it came to the definite diagnosis of broiler ascites. Subsequent investigation found that the rearing houses were closed and sealed with poor ventilation and a high breeding density and much ammonia gas.

CONCLUSION

Under the comprehensive management and drug treatments, there were 800 chickens found ill and later came back to normal from illness after the treatments, except for the death of 38 sick chickens. The appetite and drink of broiler chicken came to normal gradually.

High altitude hypoxia as a factor that promotes tibial growth plate development in broiler chickens

Tibial dyschondroplasia (TD) is one of the most common problems in the poultry industry and leads to lameness by affecting the proximal growth plate of the tibia. However, due to the unique environmental and geographical conditions of Tibet, no case of TD has been reported in Tibetan chickens (TBCs). The present study was designed to investigate the effect of high altitude hypoxia on blood parameters and tibial growth plate development in chickens using the complete blood count, morphology, and histological examination. The results of this study showed an undesirable impact on the overall performance, body weight, and mortality of Arbor Acres chickens (AACs) exposed to a high altitude hypoxic environment. However, AACs raised under hypoxic conditions showed an elevated number of red blood cells (RBCs) and an increase in hemoglobin and hematocrit values on day 14 compared to the hypobaric normoxia group. Notably, the morphology and histology analyses showed that the size of tibial growth plates in AACs was enlarged and that the blood vessel density was also higher after exposure to the hypoxic environment for 14 days, while no such change was observed in TBCs. Altogether, our results revealed that the hypoxic environment has a potentially new role in increasing the blood vessel density of proximal tibial growth plates to strengthen and enhance the size of the growth plates, which may provide new insights for the therapeutic manipulation of hypoxia in poultry TD.

Prevalence rates of health and welfare conditions in broiler chickens change with weather in a temperate climate

Climate change impact assessment and adaptation research in agriculture has focused primarily on crop production, with less known about the potential impacts on livestock. We investigated how the prevalence of health and welfare conditions in broiler (meat) chickens changes with weather (temperature, rainfall, air frost) in a temperate climate. Cases of 16 conditions were recorded at approved slaughterhouses in Great Britain. National prevalence rates and distribution mapping were based on data from more than 2.4 billion individuals, collected between January 2011 and December 2013. Analysis of temporal distribution and associations with national weather were based on monthly data from more than 6.8 billion individuals, collected between January 2003 and December 2013. Ascites, bruising/fractures, hepatitis and abnormal colour/fever were most common, at annual average rates of 29.95, 28.00, 23.76 and 22.29 per 10 000, respectively. Ascites and abnormal colour/fever demonstrated clear annual cycles, with higher rates in winter than in summer. Ascites prevalence correlated strongly with maximum temperature at 0 and -1 month lags. Abnormal colour/fever correlated strongly with temperature at 0 lag. Maximum temperatures of approximately 8°C and approximately 19°C marked the turning points of curve in a U-shaped relationship with mortality during transportation and lairage. Future climate change research on broilers should focus on preslaughter mortality.

Effects of dietary DL-2-hydroxy-4(methylthio)butanoic acid supplementation on growth performance, indices of ascites syndrome, and antioxidant capacity of broilers reared at low ambient temperature

This study examined the effects of dietary DL-2-hydroxy-4(methylthio)butanoic acid (DL-HMTBA) supplementation on growth performance, antioxidant capacity, and ascites syndrome (AS) in broilers reared at low ambient temperature (LAT) from 7 to 28 days of age. Eight hundred 7-day-old broilers were randomly assigned to two ambient temperatures (LAT and normal ambient temperature [NAT]), four supplemental DL-HMTBA levels (0.17, 0.34, 0.51, and 0.68 %) of the basal diet in a 2 × 4 factorial arrangement (ten replicate pens; ten birds/pen). LAT and NAT indicate temperatures of 12-14 and 24-26 °C in two chambers, respectively, and broilers were reared at these temperatures from 7 to 28 days of age. LAT significantly decreased body weight gain (P < 0.001), serum glutathione (GSH) content (day 14, P = 0.02; day 28, P = 0.045), glutathione peroxidase (GSH-Px) activity, and total antioxidant capacity (T-AOC) at 21 days (P = 0.001, 0.015) and 28 days (P = 0.017, 0.010) and increased feed conversion ratio (FCR) (P < 0.001), serum malondialdehyde (day 21, P = 0.000) and protein carbonyl Level (day 14, P = 0.003; day 21, P = 0.035). As for incidence of AS, there were significant effects of LAT on red blood cell (RBC) count (P < 0.05), hematocrit (HCT) (P < 0.05), and the right to total ventricular weight ratio (RV/TV) at 21 days (P = 0.012) and 28 days (P = 0.046). Supplementation of DL-HMTBA markedly decreased RV/TV at day 28 (P = 0.021), RBC (day 21, P = 0.008), HCT (day 21, P < 0.001), mean cell hemoglobin (day 14, P = 0.035; day 21, P = 0.003), and serum protein carbonyl level (day 21, P = 0.009), while significantly increased serum GSH content (day 14, P = 0.022; day 28, P = 0.001), SOD and GSH-Px activities at 21 days of age (P < 0.001 and P = 0.037). The optimal supplemental DL-HMTBA levels in basal diet of broilers aged from 7 to 28 days under low or normal temperatures were similar, so the authors recommended supplemental of DL-HMTBA level was 0.46 %.

Kelussia odoratissima Mozzaf - a promising medicinal herb to prevent pulmonary hypertension in broiler chickens reared at high altitude

ETHNOPHARMACOLOGICAL RELEVANCE

Kelussia odoratissima Mozzaf, formerly Apium odoratissima, is a plant locally called "Karafs", found in central Zagros region of Iran. Leaves and stems of the plant are traditionally used in the treatment of hypertension and inflammation. Lowering blood pressure effects of Kelussia odoratissima Mozzaf (wild celery) was evaluated in preventing pulmonary hypertension syndrome (PHS) in broiler chickens reared at high altitude (2,100 m).

MATERIALS AND METHODS

A total number of 208 day-old male broilers (Ross 308) were randomly assigned to four treatments including different levels of Kelussia odoratissima Mozzaf (0%, 0.25%, 0.5%, and 0.75%) in a 42-day trial.

RESULTS

Body weight gain and feed:gain responses significantly (P<0.05) improved when Kelussia odoratissima Mozzaf was included in broiler diets at 0.75% in the growing stage and throughout the trial. Over-expression of inducible nitric oxide (NO) synthase in the heart was observed in chickens fed Kelussia odoratissima Mozzaf. Birds received Kelussia odoratissima Mozzaf at 0.5% and 0.75% had significantly (P<0.05) higher circulatory concentrations of NO though significantly (P<0.05) lower serum malondialdehyde concentration, hematocrit and heterophil to lymphocyte ratio when compared to the birds fed the control diet. Feeding Kelussia odoratissima Mozzaf at 0.5% and 0.75% prevented from right ventricular hypertrophy and led to a significant decline in mortality from PHS.

CONCLUSION

It can be concluded that Kelussia odoratissima Mozzaf is a promising medicinal herb to prevent PHS in broiler chickens by improving blood pressure and antioxidant responses.

Effects of Rhodiola on production, health and gut development of broilers reared at high altitude in Tibet

Rhodiola has long been used as a traditional medicine to increase resistance to physical stress in humans in Tibet. The current study was designed to investigate whether Rhodiola crenulata (R. crenulata) could alleviate the negative effects of hypoxia on broiler chickens reared in Tibet Plateau. The effect of supplementing crushed roots of R. crenulata on production performance, health and intestinal morphology in commercial male broilers was investigated. Dietary treatments included CTL (basal diet), Low-R (basal diet + 0.5% R. crenulata) and High-R (basal diet + 1.5% R. crenulata). In comparison with broilers fed the control diet, Low-R had no effect on production performance while High-R significantly decreased average daily feed intake at d 14, 28 and 42, body weight at d 28 and 42 and gut development. Ascites induced mortality did not differ among treatments. Nevertheless Low-R significantly reduced non-ascites induced mortality and total mortality compared with broilers fed CTL and High-R diets. Broilers fed the High-R diet had significantly increased blood red blood cell counts and hemoglobin levels at 28 d compared with other treatments. Our results suggest that supplementation with Rhodiola might reduce the effects of hypoxia on broilers and consequently decrease mortality rate.

Effect of dietary coenzyme Q10 supplementation on the growth rate, carcass characters and cost effectiveness of broiler fed with three energy levels

The objective of this experiment was to study the effect of dietary supplementation of Coenzyme Q10 on broiler growth rate, carcass characteristics and cost of production. A biological trial was carried out with 270 broiler chicks fed with coenzyme Q10 at 0, 20 and 40 mg/kg of diet at each of the three energy levels. At the end of 42 days growth period the birds were sacrificed and the samples were analysed. Feed intake was comparable in all the energy and CoQ10 combinations, but higher body weight gain and better feed efficiency with less feed cost per kilogram weight gain was observed in high energy group supplemented with 20 mg of CoQ10/kg diet. The dressing percentages, weight of giblet, liver, spleen, abdominal fat, intestinal length were not significantly altered by CoQ10 supplementation. The heart weight, gizzard weight and ascites heart weight (AHI) were significantly decreased due to CoQ10 supplementation. Hence, birds fed with high energy diet supplemented with 20 mg CoQ10 per kg of diet had higher production performance.

Effect of Origanum chemotypes on broiler intestinal bacteria

Essential oils have been proposed as alternatives to antibiotic use in food animal production. This study evaluated 3 chemotypes of the Origanum genus, containing varying amounts of secondary metabolites carvacrol, thymol, and sabinene, in the broiler chicken diet. Aerial parts of Origanum vulgare L. (OL), O. vulgare L. ssp. hirtum (OH), and O. majorana (OM) were collected from a greenhouse located in the high altitude Sabana de Bogotá (Savanna of Bogotá) and O. vulgare L. ssp. hirtum (OG) produced and ground in Greece. Oregano essential oils (OEO) from these plants were obtained by steam distillation and analyzed by gas chromatography coupled to a mass spectrometer. Six treatments were evaluated: 200 mg/kg of OEO from OH, OL, and OM, 50 mg/kg of OEO from OG, 500 mg/kg of chlortetracycline, and without additives. Broiler chicks were maintained at 2,600 m above sea level, placed in brooder cages under a completely randomized design. Template DNA was isolated from duodenal, jejunal, ileal, and cecal contents in each group and bacterial 16S rDNA patterns were analyzed by denaturing gradient gel electrophoresis. Dendrograms of denaturing gradient gel electrophoresis band patterns revealed 2 main clusters, OEO-treated chicks and nontreated control chicks, in each intestinal segment. Band patterns from different gut compartments revealed major bacterial population shifts in the foregut (duodenum, jejunum, and ileum) compared with the hindgut (cecum and colon) at all ages evaluated (P < 0.05). The OEO groups showed less shift (62.7% similarity coefficient) between these 2 compartments versus the control groups (53.7% similarity coefficient). A reduction of 59% in mortality from ascites was seen in additive-supplemented groups compared with the control group. This study represents the first work to evaluate the effects of the 3 main chemotypes of Origanum genus in broilers.

Broiler ascites syndrome: collateral damage from efficient feed to meat conversion

Chickens have been raised as food for human consumption for over 4000 years. Over this time they have been continuously selected for specific desirable characteristics by active selection of parents to produce birds which fit perceived needs. Despite this long history of selective breeding and improvements in rearing techniques, the efficiency with which broiler meat is produced has shown a remarkable leap in recent decades. Persistent selection for rapid growth, high feed utilisation efficiency and large cut yield has resulted in modern meat-type poultry lines with superior genetic potential with regard to productivity. However, mortality and the incidence of metabolic diseases has increased in parallel with growth rate. One such disease is broiler ascites syndrome, which has been shown to be closely associated with the fast growth and high meat yield resulting from intense selection and with modern rearing techniques. The review is focused on the historical background, pathogenesis, epidemiology and prevention of broiler ascites syndrome in modern broiler production.