There is an increased interest among poultry nutritionists to increase the linoleic acid (LA) content
of the egg, which possesses many benefits for human health. This fatty acid must be provided
by the diet as the bird’s body cannot synthesise it. The present study evaluated the
influence of different levels of dietary LA on the productive performance, egg quality and yolk
lipid profile of Longyan laying ducks. In total, 900 Longyan female laying ducks aged 24 weeks
were assigned to six dietary treatments, each containing 6 replicates of 25 ducks. The six dietary
treatments contained six incremental levels of LA (analysed content: 0.36, 0.66, 0.80, 1.07, 1.28,
and 1.45%) and the experimental diets were offered for the following 20 weeks. The results
showed that different supplemental levels of dietary LA had no effects on egg production traits,
concentrations of plasma cholesterol and triglycerides, or low or high-density lipoprotein cholesterol
(p>.05). There was a linear increase in yolk colour (p<.001) and yolk cholesterol (p<.005)
with increasing dietary LA. With increased intake of LA, the yolk content in C18:1, C20:1 and
total monounsaturated fatty acids decreased linearly (all p<.005), but the concentrations of
C18:2, C18:3, C20:2, C20:3, C20:4, C20:6, and total polyunsaturated fatty acids were linearly
increased (p<.008 to <.0001). The results of the present work show that LA dietary supplementation
of Longyan duck layers positively modified the yolk fatty acid profile, increased the yolk
cholesterol, and enhanced the yolk colour.
HIGHLIGHTS

This study evaluated the effects of selenium
(Se) supplementation in maternal and offspring
diets on performance and antioxidant capacity of ducklings
aged from 0 to 2 wk. A total of 144 female Longyan
duck breeders aged 22-wk were allotted into 2 treatments
and fed a control diet or a 0.16 mg Se/kg supplemented
diet. At 40-wk, 120 offspring from each
treatment were divided into 2 groups, with 6 replicates
of 10 birds. Using a 2 £ 2 factorial design, ducklings
from each maternal dietary treatment were assigned to
a control diet or a 0.16 mg Se/kg supplemented diet
from hatch to 2-wk. Compared with Se-deficient diet,
maternal diet supplemented with 0.16 mg Se/kg
increased the BW of hatchlings (P < 0.01). There were
interactions between maternal and progeny diet with
0.16 mg Se/kg in BW of ducklings aged 2 wk and BW
gain (BWG) as ducklings from maternal Se/progeny
none treatment had the lightest BW and BWG (P <
0.01). Maternal diet with 0.16 mg Se/kg decreased
plasma concentration of uric acid and insulin-like growth
factor 1 (P < 0.01), and progeny diet supplemented with 0.16 mg Se/kg increased the activities of glutathione peroxidase
3 (GPx3) in plasma and glutathione peroxidase
1 in erythrocyte (P < 0.01). Maternal diet with 0.16 mg
Se/kg increased (P < 0.05) the hepatic activity of total
superoxide dismutase (T-SOD). Progeny diet supplemented
with 0.16 mg Se/kg increased (P < 0.01) hepatic
activity of GPx3 and decreased (P < 0.01) the hepatic
concentration of malondialdehyde. Interactions were
detected between maternal and progeny diet with
0.16 mg Se/kg in hepatic activity of T-SOD and maternal
and progeny diet supplemented with Se displayed
the highest hepatic activity of T-SOD (P < 0.05). Overall,
Se supplementation in the diet of duck breeders and
offspring increased the antioxidant capacity of ducklings.
Maternal Se supplementation increased the BW of
hatchlings, whereas maternal and progeny dietary Se
supplementation did not affect the BWG of ducklings
aged from 0 to 2 wk. Se supplementation with additional
0.16 mg/kg in the diet of duck breeders and offspring
displayed beneficial effects particularly on the antioxidant
capacity in ducklings.

A unique sperm behavior was observed in Egyptian chickens. Sperm showed a tendency to agglutinate forming motile thread-like bundles. Sperm agglutination behavior, kinematics, and some morphometric measures were studied in relation to sperm competition and fertility duration in Sharkasi and Dandarawi chickens. Sperm tendency to agglutinate was assessed by examining sperm morphology using scanning electron microscopy, Acridine orange-stained semen smears using fluorescence microscopy, and recording videos of sperm under phase contrast microscope. Sperm velocity and morphometric measures were evaluated using image-J software. To assess sperm competition, Sharkasi and Dandarawi hens were artificially inseminated by semen pools possessing equal number of Sharaksi and Dandarawi sperm. Artificial insemination was repeated ten times. The eggs obtained were incubated, and the hatchlings were discriminated as descending from Sharkasi or Dandarawi fathers according to their phenotype. To assess the fertility duration, Sharkasi and Dandarawi hens were inseminated by semen collected from roosters of the same strain. Eggs were collected for a period of 28 days post-insemination and incubated. Sharkasi spermatozoa showed higher tendency to agglutinate forming longer and thicker motile bundles. No significant differences were observed in sperm curvilinear and straight line velocity and in sperm morphometric measures between Sharkasi and Dandarawi chickens. Sharkasi roosters fathered 81.6% and 67.7% of the hatchlings produced by Sharkasi and Dandarawi mothers, respectively. The fertility period in Sharkasi and Dandarawi was 22 and 14 days, respectively. We suggest that the differences seen in sperm competitiveness and fertility duration can be attributed to sperm agglutination behavior.

Fertility in birds is dependent on their ability to store adequate populations of viable sperm for extended durations in sperm storage tubules (SSTs). The exact mechanisms by which sperm enter, reside, and egress from the SSTs are still controversial. Sharkasi chicken sperm showed a high tendency to agglutinate, forming motile thread-like bundles comprising many cells. Since it is difficult to observe sperm motility and behavior inside the opaque oviduct, we employed a microfluidic device with a microchannel cross-section resembling close to that of sperm glands allowing for the study of sperm agglutination and motility behavior. This study discusses how sperm bundles are formed, how they move, and what role they may have in extending sperm residency inside the SSTs. We investigated sperm velocity and rheotaxis behavior when a fluid flow was generated inside a microfluidic channel by hydrostatic pressure (flow velocity = 33 µm/s). Spermatozoa tended to swim against the flow (positive rheotaxis) and sperm bundles had significantly lower velocity compared to lonesome sperm. Sperm bundles were observed to swim in a spiral-like motion and to grow in length and thickness as more lonesome sperm are recruited. Sperm bundles were observed approaching and adhering to the sidewalls of the microfluidic channels to avoid being swept with fluid flow velocity > 33 µm/s. Scanning and transmission electron microscopy revealed that sperm bundles were supported by a copious dense substance. The findings show the distinct motility of Sharkasi chicken sperm, as well as sperm's capacity to agglutinate and form motile bundles, which provides a better understanding of long-term sperm storage in the SSTs.

أدى استخدام جمیع المعاملات الى نقص فى نسبة المواد الصلبة الذائبة الکلیة والسکریات المختزلة والکلیة وزیادة في نسبة الحموضة لثمار کلا الصنفین السيوي والحياني مقارنة بالثمار الغیر معاملة خلال موسمي الدراسة.

شهد العالم في الآونه الاخيرة العديد من التطورات والتغيرات الاقتصادية التي ساهمت بشكل فعال في حدوث تغيرات جذرية في حركة التجارة الخارجية بين الدول بعضها البعض, حيث عقدت مصر العديد من الاتفاقيات التجارية التي وقعتها مع الكثير من مختلف الدول والتكتلات العالمية, ففي هذا البحث تم التركيز علي اتفاقية تجمع دول الساحل والصحراء Sahel-Sahara وهي من أحدث التجمعات الاقتصادية الأفريقية. حيث وقعت هذه الاتفاقية في 4 فبراير 1998 في مدينة طرابلس بليبيا ليكون أساسا لإقامة اتحاد اقتصادی شامل بين الدول الأفريقية، وهو من التجمعات الاقتصادية الرائدة التي تعمل على تنمية العلاقات الاقتصادية العربية الأفريقية. لذا استهدف البحث بصفة اساسية الوقوف علي أثر اتفاقية تجمع دول الساحل والصحراء (س.ص) Sahel-Sahara علي التجارة الخارجية وانعكاساتها علي الميزان التجاري المصري بصفة عامة والزراعي والغذائي بصفة خاصة

        شهد العالم في الآونه الاخيرة العديد من التطورات والتغيرات الاقتصادية التي ساهمت بشكل فعال في حدوث تغيرات جذرية في حركة التجارة الخارجية بين الدول بعضها البعض, حيث عقدت مصر العديد من الاتفاقيات التجارية التي وقعتها مع الكثير من مختلف الدول والتكتلات العالمية, ففي هذا البحث تم التركيز علي اتفاقية تجمع دول الساحل والصحراء Sahel-Sahara وهي من أحدث التجمعات الاقتصادية الأفريقية. حيث وقعت هذه الاتفاقية في 4 فبراير 1998 في مدينة طرابلس بليبيا ليكون أساسا لإقامة اتحاد اقتصادی شامل بين الدول الأفريقية، وهو من التجمعات الاقتصادية الرائدة التي تعمل على تنمية العلاقات الاقتصادية العربية الأفريقية. لذا استهدف البحث بصفة اساسية الوقوف علي أثر اتفاقية تجمع دول الساحل والصحراء (س.ص) Sahel-Sahara علي التجارة الخارجية وانعكاساتها علي الميزان التجاري المصري بصفة عامة والزراعي والغذائي بصفة خاصة

Optimizing the dietary calcium (Ca) level is essential to maximize the eggshell quality, egg production and bone formation in poultry. This study aimed to establish the Ca requirements of egg-type duck breeders from 23 to 57 weeks of age on egg production, eggshell, incubation, tibial, plasma and ovary-related indices, as well as the expression of matrix protein-related genes. Totally, 450 Longyan duck breeders aged 21 weeks of age were allotted randomly into five treatments, each with six replicates of 15 individually caged birds. The data collection started from 23 weeks of age and continued over the following 35 weeks. The five groups corresponded to five dietary treatments containing either 2.8%, 3.2%, 3.6%, 4.0% or 4.4% Ca. The tested dietary Ca levels increased (linear, P <0.01) egg production and egg mass, and linearly improved (P <0.01) the feed conversion ratio (FCR). Increasing the dietary Ca levels from 2.8% to 4.4% increased (P <0.01) the eggshell thickness and eggshell content. The tested Ca levels showed a quadratic effect on eggshell thickness and ovarian weight (P <0.01); the highest values were obtained with the Ca levels 4.0% and 3.6%, respectively. Dietary Ca levels affected the small yellow follicles (SYF) number and SYF weight/ovarian weight, and the linear response (P <0.01) was significant vis-à-vis SYF number. In addition, dietary Ca levels increased (P <0.05) the tibial dry weight, breaking strength, mineral density and ash content. Plasma and tibial phosphorus concentration exhibited a quadratic (P <0.01) response to dietary Ca levels. Plasma calcitonin concentration linearly (P <0.01) increased as dietary Ca levels increased. The relative expression of carbonic anhydrase 2 in the uterus rose (P <0.01) with the increment of dietary Ca levels, and the highest value was obtained with 3.2% Ca. In conclusion, Longyan duck breeders fed a diet with 4.0% Ca had superior eggshell and tibial quality, while those fed a diet with 3.6% Ca had the heaviest ovarian weights. The regression model indicated that the dietary Ca levels 3.86%, 3.48% and 4.00% are optimal levels to obtain maximum eggshell thickness, ovarian weight and tibial mineral density, respectively.

This study was aimed at estimating the dietary manganese (Mn) requirement for laying duck breeders. A total of 504 Longyan duck breeders (body weight: 1.20 ± 0.02 kg) aged 17 wk were randomly allocated to 6 treatments. The birds were fed with a basal diet (Mn, 17.5 mg/kg) or diets supplemented with 20, 40, 80, 120, or 160 mg/kg of Mn (as MnSO₄·H₂O) for 18 wk. Each treatment had 6 replicates of 14 ducks each. As a result of this study, dietary Mn supplementation did not affect the productive performance of laying duck breeders in the early laying period (17–18 wk), but affected egg production, egg mass, and feed conversion ratio (FCR) from 19 to 34 wk (P < 0.05), and there was a linear and quadratic effect of supplement level (P < 0.05). The proportion of preovulatory ovarian follicles increased (P < 0.01) linearly and quadratically, and atretic follicles (weight and percentage) decreased (P < 0.05) quadratically with dietary Mn supplementation. The density and breaking strength of tibias increased (quadratic; P < 0.05), the calcium content of tibias decreased (linear, quadratic; P < 0.01), and Mn content increased (linear, quadratic; P < 0.001) with increase in Mn. The addition of Mn had a quadratic effect on serum contents of estradiol, prolactin, progesterone, luteinizing hormone, and follicle-stimulating hormone (P < 0.001). Dietary Mn supplementation decreased serum contents of total protein (linear, P < 0.05), glucose (quadratic, P < 0.05), total bilirubin, triglycerides, total cholesterol, low-density lipoprotein cholesterol, and calcium (linear, quadratic; P < 0.05). The serum total antioxidant capacity and total and Mn-containing superoxide dismutase activities increased (linear, quadratic; P < 0.001), and malondialdehyde content decreased (linear, quadratic; P < 0.001) in response to Mn supplemental levels. The dietary Mn requirements, in milligram per kilogram for a basal diet containing 17.5 mg/kg of Mn, for Longyan duck breeders from 19 to 34 wk of age were estimated to be 84.2 for optimizing egg production, 85.8 for egg mass, and 95.0 for FCR. Overall, dietary Mn supplementation, up to 160 mg/kg of feed, affected productive performance, tibial characteristics, and serum biochemical and antioxidant status of layer duck breeders. Supplementing this basal diet (17.5 mg/kg of Mn) with 85 to 95 mg/kg of additional Mn was adequate for laying duck breeders during the laying period.

This study evaluated the effects of barley inclusion and glucanase supplementation on the productive
performance and digestive function in laying ducks. The experiment used a randomized design with a
5
2 factorial arrangement of 5 graded levels of barley (0%, 15%, 30%, 45% and 60%) with or without 1.5 g/
kg b-1,3-1,4-glucanase (15,000 U/kg). During the experimental period of 120 d, the weight and total
number of eggs within each pen were recorded daily, and egg quality was determined every 4 wk. At the
end of the experiment, 3 randomly selected ducks within each replicate were sacrificed, then duodenal
digesta and jejunal mucosa was collected. Dietary inclusion of barley had no effects on egg production,
daily egg mass or FCR, but supplementation with glucanase improved egg production and FCR (P < 0.01).
Barley did not affect feed intake of laying ducks, but glucanase tended to increase feed intake (P ¼ 0.09).
Neither barley nor b-glucanase had effects on the egg quality variables, except for yolk color score, which
was decreased with increasing barley supplementation. Glucanase, but not barley, increased the activity
of chymotrypsin and amylase in duodenal digesta. Barley inclusion affected the activity of alkaline
phosphatase and maltase in jejunal mucosa (P < 0.05), but b-glucanase had no effects on the activity of
these brush border enzymes. Barley inclusion increased the glucan content in duodenal digesta, but
supplementation of glucanase to barley-based diet reduced digesta glucan content and reduced total
volatile fatty acids and increased the proportion of acetic acid in cecal contents. The results indicate that,
without glucanase, the optimal dietary barley level in the diets of laying ducks is about 13% for maximal
production performance; glucanase supplementation of the barley diets improved production performance,
probably through enhancing digestive function.