Effects of dietary crude protein and electrolyte balance on production parameters and blood biochemicals of laying hens under tropical summer condition

The objective of this study was to determine the effects of different levels of crude protein (CP) and dietary electrolyte balance (DEB) on productive performance, egg quality, and blood biochemical parameters of laying hens reared during hot summer months. The average minimum and maximum room temperatures recorded from 32 to 42 weeks of age were 27.2 and 36.5 °C, respectively, with relative humidity ranging from 48 to 56 %. A total of 144 Lohmann LSL-Lite laying hens were assigned to each of four dietary treatments with six replicate cages of six birds. The treatments were as follows: CP 15.4 % + DEB 165 mEq/kg (group 1), CP 15.4 % + DEB 250 mEq/kg (group 2), CP 13.9 % + DEB 165 mEq/kg (group 3), and CP 13.9 % + DEB 250 mEq/kg (group 4). In groups 3 and 4, feed conversion ratio and blood uric acid were decreased (P?<?0.05); but the plasma triglyceride level was increased (P?<?0.05) compared to groups 1 and 2. Low-CP diet with DEB 250 (group 4) also induced significant increases of average egg production and eggshell thickness compared to group 1. Blood pH, Na⁺, and HCO₃ ^? values were also higher (P?<?0.05) in groups 2 and 4 than in the other groups. These results indicate that, under tropical conditions, using a DEB of 250 mEq/kg achieves a correction of the lay-induced metabolic acidosis and induces a positive effect on eggshell quality when the hens were fed low-protein diet.     

Responses of ‘Petopride’ processing tomato to partial rootzone drying at different phenological stages

Partial rootzone drying (PRD) is a water-saving irrigation practice which involves watering only part of the rhizosphere at each irrigation with the complement left to dry to a pre-determined level. The effect of PRD, applied at different phenological stages, on yield, fruit growth, and quality of the processing tomato cv. ‘Petopride’ was studied in this experiment. The treatments were: daily full irrigation (FI) on both sides of the root system considered as the control, and PRD treatments applied at three phenological stages. These were: during the vegetative stage until the first truss was observed (PRD_VS–FT), from the first truss to fruit set (PRD_FT–FS), and from fruit set to harvest (PRD_FS–H). In some occasions, leaf xylem water potential was lower in each PRD period than in FI. Number of fruits, total fresh and dry weight of fruit per plant, harvest index, and fruit growth were lower in PRD_FT–FS and PRD_FS–H plants than in FI and PRD_VS–FT plants. However, irrigation water use efficiency, on a dry weight basis, was the same among the treatments. For PRD_FT–FS and PRD_FS–H treatments, mean fresh weight of fruit and fruit water content were reduced and dry matter concentration of cortex and total soluble solids concentration of fruit increased compared with FI and PRD_VS–FT treatments. Incidence of blossom-end rot was the same among PRD_VS–FT, PRD_FS–FH, and FI fruit, but it was higher in PRD_FT–FS fruit. Fruit skin colour was the same among treatments. Total dry weight of fruit per plant decreased by 23% for PRD_FT–FS and by 20% for PRD_FS–H relative to FI. Fruit quality improvement in PRD_FS–H could compensate for the reduction in total dry weight of fruit where water is expensive for tomato production. But an economical analysis would be needed to substantiate this. PRD from the first truss to fruit set is not recommended because of the high incidence of blossom-end rot. An erratum to this article can be found at     

The effect of safranal on histamine (H1) receptors of guinea pig tracheal chains

The effect of three concentrations of safranal on histamine (H₁) receptors was tested on two groups of tracheal chains incubated with: 1) indomethacin, and 2) indomethacin, propranolol and atropine (n = 6). The EC₅₀ (effective concentration of histamine causing 50% of maximum response) obtained in the presence of chlorpheniramine and all concentrations of safranal in both groups were significantly greater than those of saline (p < 0.05 to p < 0.001). The EC₅₀ obtained in the presence of all concentrations of safranal and maximum response of its two higher concentrations (1.25 and 2.5 μg/mL) in group 2 were greater than in group 1 (p < 0.05 to p < 0.001).     

Assessment of the biological control capability of <Emphasis Type="Italic">Hippodamia variegata</Emphasis> (Col.: Coccinellidae) using functional response experiments

Lady beetles are among the most successful predators of aphids in different environments. The functional responses of different life stages of Hippodamia variegata (Goeze) towards cotton aphids were examined in two different set-ups, a two-dimensional Petri dish set-up with detached leaves and a three-dimensional set-up with whole plants. In addition, the functional responses in two-dimensional set-ups towards cotton aphids and the pea aphids were compared. H. variegata exhibited a functional type II response to both cotton aphids and pea aphids irrespective of life stage and spatial scale of the set-up. Females and fourth instars generally had higher search rates than third instars whereas handling times were consistently lower for the fourth instar stage compared with the preceding juvenile stage and with females. The spatial dimensions did not have any significant influence on the functional responses towards cotton aphids, except for third instars which in the three-dimensional set-up reduced their search rate and increased their handling time. Fourth instars reacted in the same way to both Aphis gossypii and Acyrthosiphon pisum whereas the functional response parameters for third instars and females were significantly different on the two prey species. Our study, a part of this first-step evaluation of H. variegata as a biocontrol agent against A. gossypii and A. pisum under field condition, suggest that the voracity of all tested stages of H. variegata towards both aphid species hold good promises for a use of especially fourth instars and females in inundative biocontrol.     

Gene expression of endothelin-1 and its receptors in the heart of broiler chickens with T(3)-induced pulmonary hypertension

To investigate the effect of T₃-induced pulmonary hypertension on endothelin (ET) production and genes expression of ET-1, ET_A and ET_B receptors (ET_AR and ET_BR) during rearing, semiquantitative RT-PCR and enzyme immunometric assay were performed in the heart ventricles and serum, respectively. The ET-1 and its receptor genes were expressed in the right and left ventricles of control and T₃-treated broilers at 12, 28 and 49 days of age. There were significant (P < 0.05) reductions of the relative amounts of ET-1 (in both ventricles) and ET_AR (in the right ventricle) mRNAs at 28 and 49 days of age, in T₃-treated broilers compared to controls. The relative amounts of ET_BR mRNA in the right and left ventricles did not significantly differ between control and T₃-treated broilers at any age. The serum level of ET was significantly (P < 0.05) increased in T₃-treated chickens at 28 and 49 days of age when compared with that of the control. It is concluded that ET-1, ET_AR and ET_BR genes are normally expressed in the heart ventricles of broilers. It is likely that increased serum level of ET and decreased ET-1/ET_AR genes expression in the ventricles are involved in the heart dysfunction of broiler chickens with developmental pulmonary hypertension.     

Blood parameters in female Zandi lambs as affected by liver biopsy methodology

The aim of the present study was to investigate the normal blood parameters of Iranian fat-tailed sheep (Zandi) and their changes due to rapid liver biopsy technique with a tru-cut biopsy needle. In ten ewe lambs, blood samples were collected from jugular vein and biopsy needle was inserted through the dorsal one third of the 11th intercostal space, on the right hand side of the lambs and liver specimen was collected. Physical examinations were performed on alternate days during the experiment. Blood collection was done on both before (day 1) and after (day 17) the biopsy. All animals were slaughtered at day 17. Values were compared using paired t test. While biopsy did not make any significant changes in mean values of body temperature, heart rate, respiratory rate, PCV, WBC, neutrophil, lymphocyte, eosinophil, monocyte, total serum protein, AST, ALT, and serum calcium (p > 0.05), it made a significant difference on the values of ALP (p < 0.001), serum inorganic phosphate (p = 0.035), and magnesium (p = 0.013). Necropsy examination revealed the points of hitting the biopsy needles on the diaphragmatic surface of the livers, surrounded by a zone of intense hyperemia. Peritoneal adhesions accompanying with typical strands of fibrous connective tissue between diaphragmatic surface of the liver and adjacent abdominal wall were found in two cases.     

A survey on hydatidosis in livestock in Northern Iran based on data collected from slaughterhouses from 2004 to 2008

Data have been collected from slaughterhouses in three provinces across the Northern Iran (Gilan, Mazandaran and Golestan) from March 2004 to March 2008. These data were collected to evaluate the prevalence of hydatidosis in slaughtered cattle, sheep and goats. During the study, 3,347,797 animals were slaughtered. These included 621,686 cattle, 1,719,725 sheep and 1,006,386 goats. The prevalence of infection in cattle, sheep and goats was 12%, 14.6% and 10.1%, respectively. The association of condemnation rates with seasons was not proven statistically.     

Fruit thinning in ‘Conference’ pear grown under deficit irrigation: Implications for fruit quality at harvest and after cold storage

Fruit thinning in pear is feasible for mitigation of water stress effects. However, it is not well known how fruit quality at harvest and after cold storage is affected by pre-harvest water stress. Even less is known about the effects of fruit thinning on quality under these circumstances. To elucidate these, we applied deficit irrigation (DI) and fruit thinning treatments to ‘Conference’ pear over the growing seasons of 2008 and 2009. At the onset of Stage II (80 and 67 days before harvest in 2008 and 2009, respectively), two irrigation treatments were applied: full irrigation (FI) and DI. FI trees received 100% of crop evapotranspiration (ETc). DI trees received no irrigation during the first three weeks of Stage II to induce water stress, but then received 20% of ETc to ensure tree survival. From bud-break until the onset of Stage II and during post-harvest, FI and DI trees received 100% of ETc. Each irrigation treatment received two thinning levels: no thinning leaving commercial crop load (∼180 fruits tree⁻¹), and hand-thinning at the onset of Stage II leaving a light crop load (∼85 fruits tree⁻¹). Under commercial crop loads, DI trees were moderately water-stressed and this had some positive effects on fruit quality. DI increased fruit firmness (FF), soluble solids concentrations (SSC) and acidity at harvest while no changes were observed in fruit maturity (based on ethylene production). Differences in FF and acidity at harvest between FI and DI fruit were maintained during cold storage. DI also reduced fruit weight loss during storage. But fruit size was reduced under DI. Fruit thinning under DI resulted in better fruit composition with no detrimental effect on fresh-market yield compared to un-thinned fruit. Fruit size at harvest and SSC values after five months of cold storage were higher in fruit from thinned trees than fruit from un-thinned trees. Fruit thinning increased fruit ethylene production, indicating advanced maturity. This may lead to earlier harvest which is desirable in years with impending drought. Fruit thinning is therefore a useful technique to enhance pear marketability under water shortage.