Blood gas values and pulmonary hypertension as affected by dietary sodium source in broiler chickens reared at cool temperature in a high-altitude area

Animal protein-soybean oil-based broiler diet optimizes net profit at the expense of desirable ω-6 fatty acids from the breast muscle of the broiler chicken

Total 288 Ross-308-day-old male broiler chicks were randomly distributed into six dietary treatment groups in a two-way ANOVA with 2 × 3 factorial arrangements (two factors, i.e., dietary protein and energy having two types of protein, e.g., plant, animal and three different sources of energy, e.g., soybean oil, rice bran oil and sunflower oil) to justify if animal protein-soybean oil based broiler diet optimizes net profit at the expense of desirable ω-6 fatty acids in the breast muscle of the broiler chicken. Average daily feed intake (ADFI), final live weight (FLW), average daily gain (ADG), feed efficiency (FE), carcass characteristics, cardio-pulmonary morphometry, fatty acid profile of the breast muscle and cost-benefit analysis were measured. Results indicated that animal protein significantly increased 4.27% FLW, 6.13% ADFI, 4.31% ADG and 2.93% wing weight. Accordingly, soybean oil increased 4.76% FLW, 3.80% ADG and 1.36% dressing percentage at the expense of 12.07% proventriculus weight compared with sunflower oil. The generalized linear model identified no interaction effects of the sources of protein and energy on overall performance of the birds. Replacement of vegetable protein by animal protein decreased 14.01% ∑ω-3, 12.16% ∑ω-6 and 12.21% sum of polyunsaturated fatty acids (∑PUFA) and concomitantly increased 10.82% sum of saturated fatty acids (∑SFAs) in the breast muscle (Pectoralis major). Accordingly, replacement of sunflower oil by soybean oil decreased 29.17% ∑ω-3, 6.71% ∑ω-6, 11.62% sum of monounsaturated fatty acids (∑MUFAs) and 7.33% ∑PUFAs and concurrently increased 18.36% ∑SFAs in the breast muscle of the broiler birds. It was concluded that animal protein-soybean oil-based broiler diet optimized net profit at the expense of desirable ω-3 and ω-6 fatty acids in the breast muscle of the broiler chicken.

Which source and level of dietary sodium is appropriate for broiler chickens reared in a high-altitude area?

This study investigated effect of increasing level of dietary sodium using sodium bicarbonate or sodium chloride on growth performance, mortality, characteristics of carcass, organs and tibia, calcium and phosphorus of serum in broilers reared in a high-altitude area (1,700 m above sea level). A total of 588 Ross 308 male broiler chicks were used in seven treatments, six replicates per treatment of 14 birds per each from 1 to 38 d of age. Seven dietary treatments consisted of a basal diet (with 0.16% sodium and 0.23% chloride), top-dressed for six diets to give three supplementary levels of sodium (0.07%, 0.14% and 0.21%) from sodium bicarbonate (respectively by 0.26%, 0.52% and 0.78%) or sodium chloride (respectively by 0.18%, 0.36% and 0.54%), resulting in seven diets with total sodium and chloride levels of 0.16% and 0.23%, 0.23% and 0.23%, 0.30% and 0.23%, 0.37% and 0.23%, 0.23% and 0.33%, 0.30% and 0.44%, 0.37% and 0.55% respectively. Increasing sodium level improved feed conversion ratio (FCR) linearly and quadratically. However, when FCR was calculated without adjusting for feed intake of mortalities, the enhanced sodium level did not improve this parameter. Increasing sodium level via sodium chloride enhanced ascites mortality, total mortality, relative weight of heart and right ventricle linearly. Increasing sodium level reduced serum calcium and enhanced serum phosphorus linearly; however, there was a linear tendency to increase tibia ash when sodium level was enhanced by sodium bicarbonate (p = 0.08) or sodium chloride (p = 0.07). Increasing sodium level via sodium bicarbonate tended (p = 0.08) to reduce tibia strength linearly. In conclusion, a diet with 0.16% sodium and 0.23% chloride is enough for broiler chicken reared in a high-altitude area, and increasing dietary sodium level via sodium chloride has detrimental effect on survivability of broiler in such condition.

Pulmonary hypertension and right ventricular failure in broiler chickens reared at high altitude is affected by dietary source of n-6 and n-3 fatty acids

The present study evaluated the development of pulmonary hypertension and right ventricular failure in broiler chickens reared at high altitude (2100 m) as affected by dietary intake of n-3 and n-6 fatty acid sources. Flax oil and soy oil were used as sources of n-3 and n-6 fatty acids, respectively, either with or without α-tocopheryl acetate. A total of 192 day-old broiler chicks (Ross 308) were used in a completely randomized design using isoenergetic and isonitrogenous experimental diets. Results showed that dietary flax oil significantly (p < 0.05) improved feed conversion ratio during 21-42 days of age. However, body weight gain did not significantly differ among the experimental groups in entire trial. Birds received flax oil had significantly higher serum concentration of nitric oxide (NO) but they had lower serum concentration of malondialdehyde when compared with their counterparts fed with soy oil. Liver and abdominal fat weights were significantly (p < 0.05) reduced by substitution of soy oil for flax oil. The right-to-total ventricle weight ratio (RV/TV) and mortality from pulmonary arterial hypertension (PAH) were significantly (p < 0.05) decreased in birds that received flax oil. In conclusion, n-3 fatty acids could significantly reduce RV:TV and PAH mortality in birds by increasing circulatory level of NO and suppressing hepatic lipogenesis.

L-arginine supplementation of reduced-protein diets improves pulmonary hypertensive response in broiler chickens reared at high altitude

This study was conducted at high altitude (2100 m above sea level). A total of 208 d-old male broilers (Ross 308) were randomised across 16 floor pens and reared up to 42 d. A normal-protein diet (NPD) was formulated according to the National Research Council. A reduced-protein diet (RPD) was prepared with dietary protein reduced by 30 g/kg relative to that of the NPD. Two additional diets were prepared by adding 2 and 4 g L-arginine (ARG)/kg to the RPD. At the end of trial (42 d), blood sampling was done and carcass characteristics were recorded. ARG supplementation of the RPD at 4 g improved feed:gain in the growing stage and throughout the trial compared with the RPD. The right-to-total ventricular weight ratio was significantly increased in birds fed on RPD compared with those fed on NPD or ARG-supplemented RPD. Feeding RPD caused a significant decrease in plasma concentrations of nitric oxide (NO) and uric acid. Plasma NO level, however, was restored by ARG supplementation of RPD. ARG supplementation of RPD, however, significantly reduced the rate of pulmonary hypertension syndrome mortality compared to the negative control fed on RPD.

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.

L-carnitine supplementation decreases lipid peroxidation and improves cardiopulmonary function in broiler chickens reared at high altitude

An experiment was carried out to examine the effects of L-carnitine supplementation on growth performance and cardiopulmonary function of broiler chickens reared at high altitude (2100 m above sea level). A total of 96 day-old male chicks (Cobb 500) were randomly assigned into two dietary treatments containing 0 (control group) and 200 mg/kg L-carnitine. The experimental diets were fed for a period of 42 days consisting of the starting (days 1 to 21) and growing periods (days 21 to 42). Nutrient requirements of chickens met the NRC (1994) recommendations. The results showed that dietary L-carnitine had no significant influence on body weight gain, feed intake and feed conversion ratio. L-carnitine reduced plasma concentration of malondialdehyde, packed cell volume (PCV) and abdominal fat deposition compared to the control (P < 0.05). A significant (P < 0.05) decrease was observed in the right to total ventricular weight ratio (RV:TV) in birds receiving L-carnitine when compared to the control. Supplementation of L-carnitine increased plasma nitric oxide and immune responsiveness, which manifested in an increased toe-web thickness index measured at 24 h following the injection of phytohaemagglutinin P. In conclusion, supplementation of L-carnitine had beneficial effects on preventing lipid peroxidation and pulmonary hypertension in broiler chickens raised at high altitude.

An L-Arginine supplement improves broiler hypertensive response and gut function in broiler chickens reared at high altitude

An experiment was carried out to examine the effects of supplemental dietary arginine (ARG) on growth, hypertensive response, and gut function in broilers reared at high altitude (2,100 m). A total of 120 day-old male broilers (Cobb 500) were divided equally into two treatment groups. Treatments included a control basal diet composed of corn and soybean meal and an experimental diet to which an L-ARG supplement was added at 10 g/kg. The trial lasted for 42 days. There were no treatment differences with regard to feed intake, body weight gain, or feed conversion ratio. However ARG supplementation did increase the plasma concentration of nitric oxide, a potent vasodilator (P<0.05), and attenuated indices of pulmonary hypertension as reflected by reductions in the hematocrit and the right to total ventricular weight ratio (P<0.05). Significantly enhanced intestinal mucosal development was observed in broilers receiving ARG supplement when compared with controls (P<0.05), suggesting that ARG supplementation increased the absorptive surface area of the jejunum and ileum. In conclusion, broiler diets supplemented with ARG beneficially improved pulmonary hemodynamics and appeared to enhance gut function.

Factors that affect the nutritive value of canola meal for poultry

This article reviews the factors affecting the nutritive value of canola meal (CM), including glucosinolates, sinapine, phytic acid, tannins, dietary fiber, and electrolyte balance. It also addresses the means of improving the nutritive value of CM throughout seed dehulling, development of low-fiber canola, or application of feed enzymes. Over the years, the glucosinolate content of canola has been declining steadily and is now only about one-twelfth of that of the older high-glucosinolate rapeseed (that is, 10 vs. 120 μmol/g). Therefore, the rations for broilers or laying hens could now contain 20% of CM without producing any adverse effects. Tannins are of lesser importance due to their presence in the hull fraction and thus low water solubility. Sinapine has been implicated with the production of a "fishy" taint in brown-shelled eggs, which results from a genetic defect among the strain of Rhode Island Red laying hens. The White Leghorns have been reported not to be affected. Although lower in protein, CM compares favorably with soybean meal with regard to amino acid content. Because CM contains more methionine and cysteine but less lysine, both meals tend to complement each other when used together in poultry diets. Canola meal is low in arginine (Arg) which could be of importance when introducing CM to broiler diets at high inclusion rates. The Arg content of CM is approximately two-thirds of that of soybean meal. Chickens fail to synthesize Arg and are highly dependent on dietary sources for this amino acid. Supplementation of Arg to CM-based diets has been shown to partly restore the growth performance. Dietary cation-anion difference in CM is also less than optimal due to the high sulfur and low potassium contents. Seed dehulling has not been very successful due to excessive fineness and thus difficulties with percolation of the miscella through the cake. Development of low-fiber, yellow-seeded canola and the use of enzymes have proven to increase the energy utilization and the nutritive value of CM for poultry.

Effect of dietary electrolyte balance on production, immune response and mineral concentrations of the femur in broilers

The aim of this study was to assess the age-related effects of dietary electrolyte balance (DEB) on the performance, immune response (from day 0 to 42) and macromineral content of femur ash of broilers. The DEB values of the purchased commercial broiler diets were modified with the addition of NH4Cl or NaHCO3 to formulate the diets (DEB 325, 250, 175, 100, 25 and -50 mmol/kg) for this investigation. A total of 396 chickens were divided into 6 treatment groups and fed with the experimental diets for 6 weeks. During the first two weeks of life, DEB did not influence feed intake and body weight gain; however, by the 21st day of age DEB 175 and between 22 and 42 days of age DEB 250 mmol/kg gave significantly better results than the control. DEB did not affect the macromineral concentrations of bone ash. The immune response of broilers on low DEB (< 175 mmol/kg) was faster and more intensive than that of chickens on diets with medium or high DEB (> 175 mmol/kg). It can be concluded that the optimal DEB value required for the best body weight gain is significantly influenced by the age of broilers. Our results call attention to the discrepancy between the decreasing DEB level of commercial broiler diets and the age-related increase of 'electrolyte requirements' of broilers. It is also interesting that DEB may influence not only the performance but also the immune response of broilers.