Total Egg Mass Research Articles

Metabolic Rate and Egg Production in Japanese Quails Can Be Predicted by Assessing Growth Parameters of Laying Hens.

The aim of the current study was to assess the female metabolic rate and test the hypothesis that there is a relationship between the egg productivity of Japanese quails from eight breeds and their morphometric, or growth, parameters. Parameters measured were body weight (B), volume (V), and surface area (S), as well as the metabolism level expressed by the ratio S/V. The collected egg performance traits were as follows: the number of eggs produced (N), the average egg weight (W), and the total egg mass (M) (i.e., N multiplied by W). To measure the S and V values, a novel technique was developed that takes into account the similarity of the quail's body to an ellipsoid. An analysis of the relationships between productivity indicators allowed us to introduce a new index called the metabolic index, B·S/V, based on all three main growth parameters in quails. Using the values of this index, we were then able to judge indirectly the level of quails' egg productivity. We went on to assess the N, W, and M values, not only depending on the size of the bird's growth parameters but also according to the degree of their changes during quail growth. These changes were expressed as the slope angles of trend lines describing the growth process data. This approach produced more accurate results for predicting the egg productivity in terms of W and M.

Fatty acids derived from oviposition systems guide female black soldier flies (Hermetia illucens) toward egg deposition sites.

The black soldier fly, Hermetia illucens, comes with big promises for industrial purposes since its larvae feed polyphagously on a broad spectrum of organic substrates. However, research focusing on adult flies is scarce, which is inconsistent with their reproductive relevance within the rearing cycle. In particular, directed oviposition is a challenge in artificial systems. Currently, decomposing organic matter is commonly used as oviposition substrate, which has extensive potential for improvement in view of the lack of standardization and the risk of microbial contamination. Here, we identified three fatty acids and one fatty acid methyl ester derived from the surface of old oviposition sites and targeted to elucidate their effect on preference behavior and oviposition site selection using Y-olfactometry and prepared oviposition sites, respectively. Exposure to tetradecanoic acid attracted gravid females and stimulated oviposition most strongly, while decanoic acid demonstrated a repulsive effect. Females kept in mixed-sex populations were attracted by tetradecanoic acid, resulting in a higher egg mass found in the compound box (3.0-11.4 fold), a ≥ 2.3 fold reduction of nonspecifically deposited eggs, and the highest total egg mass. Conversely, decanoic and dodecanoic acid caused females to lay a greater proportion of eggs nonspecifically outside both boxes. Our data suggest that fatty acids, especially tetradecanoic acid, are important cues for oviposition site selection in black soldier flies. In order to achieve a directed oviposition behavior, the role of further short- and long-chain fatty acids as attractants should be examined.

Effect of Use Different of L-Carnitine on Productive Performance on Egg of Two Breeds of Japanese Quail

This study was conducted on 270 quail females at the age of 42 days from two strains of Japanese quail, the desert and white, in order to show the effect of the strain and the levels of carnitine (0,200,250) mg carnitine/kg feed by three treatments and three replicates for each strain during the egg production stage (42-101) days. The results of study showed that there was a significant difference (p≤0.05) for the effect of strain on the number of eggs, the ratio of egg production HD%, the height of albumen, and the height of yolk, while there were no significant differences in egg weight, total egg mass, egg white ratio, yolk ratio, shell ratio shell thickness, yolk diameter, feed consumption rate, and feed conversion efficiency and mortlity ratio. The results showed, in relation to the effect of carnitine levels, that there were a significant differences (p≤0.05) in the characteristics of egg weight, total egg number, total egg mass, HD% egg albumen height, and yolk diameter, while the differences were not significant in the characteristics of whiteness and yolk ratio, shell, thickness of shell,, feed consumption rate (g/bird), feed conversion efficiency g/g egg, and mortality ratio. As for the effect of the interaction between the quail strains and three levels of carnitine, the results of the statistical analysis showed that there were significant differences (p≤0.05) in the egg weight, the number and the mass of the total egg, HD%, the ratio of whiteness, yolk, shell, height and diameter of the albumen, feed consumption rate, and feed conversion efficiency, while the difference were not significant in the ratio of yolk, thickness of shell, height of yolk and the ratio of mortality

Tradeoffs explain scaling, sex differences, and seasonal oscillations in the remarkable weapons of snapping shrimp (Alpheus spp.).

Evolutionary theory suggests that individuals should express costly traits at a magnitude that optimizes the trait bearer's cost-benefit difference. Trait expression varies across a species because costs and benefits vary among individuals. For example, if large individuals pay lower costs than small individuals, then larger individuals should reach optimal cost-benefit differences at greater trait magnitudes. Using the cavitation-shooting weapons found in the big claws of male and female snapping shrimp, we test whether size- and sex-dependent expenditures explain scaling and sex differences in weapon size. We found that males and females from three snapping shrimp species (Alpheus heterochaelis, Alpheus angulosus, and Alpheus estuariensis) show patterns consistent with tradeoffs between weapon and abdomen size. For male A. heterochaelis, the species for which we had the greatest statistical power, smaller individuals showed steeper tradeoffs. Our extensive dataset in A. heterochaelis also included data about pairing, breeding season, and egg clutch size. Therefore, we could test for reproductive tradeoffs and benefits in this species. Female A. heterochaelis exhibited tradeoffs between weapon size and egg count, average egg volume, and total egg mass volume. For average egg volume, smaller females exhibited steeper tradeoffs. Furthermore, in males but not females, large weapons were positively correlated with the probability of being paired and the relative size of their pair mates. In conclusion, we identified size-dependent tradeoffs that could underlie reliable scaling of costly traits. Furthermore, weapons are especially beneficial to males and burdensome to females, which could explain why males have larger weapons than females.

Large-brained birds lay smaller but heavier clutches

The brain is among the most energetically costly organs in vertebrates, and thus trade-offs have been hypothesized to exert constraints on brain size evolution. The energy trade-off hypothesis (ETH) predicts that reducing the energy consumption of reproduction or other costly tissues should compensate for the cost of a large brain. Egg production in birds requires a large proportion of the total energy budget, and a clutch mass in some bird species can outweigh the body mass of the female. To date, this hypothesis has mainly been tested in mammals and ectothermic animals such as anurans and fishes. We collated data on adult brain size, body mass and egg-production traits such as clutch size, egg mass and annual broods from published studies, and conducted a phylogenetic comparative test of the interplay between egg-production investment and brain size evolution across bird species. After controlling for phylogenetic relationships and body size, we find a negative correlation between brain size and clutch size across 1395 species, which favored ETH. However, when egg mass was integrated in models, positive associations were detected between brain size and mass of eggs (via egg mass, clutch mass and annual total egg mass). Our results suggest that brain size trades off against egg-production only via certain aspects (e.g., clutch size). By contrast, a positive relationship between brain size and total egg reproduction (e.g., clutch mass and annual total egg mass) implied increased total energy budget outweighing energy allocation across bird species. Our study shows that there is no general energy trade-off between brain size and egg-reproduction investment, and suggests that brain size evolution follows mixed strategies across bird species.

The use of peppermint (Mentha piperita) leaves meal reduces ammonia excreta, increases egg production, and egg quality of laying hens

A study was carried out to determine the effect of peppermint (Mentha piperita) leaves meal on ammonia production, dry matter excreta, egg production, and the quality of laying hens. A total of 80 laying hens of Lohmann Strain aged 20 weeks old were used as experimental animals. The birds were allocated in individual battery pens. The 20-week-old laying hens were vaccinated for New Castle diseases protection by using Vaksimune®ND B1on day 5 after arrival. The hens were kept for 8 weeks and fed four experimental diets. The diets used were basal diet (BSL), basal + 1% peppermint leaves meal (PLM) (BSL+1PLM), basal + 2% PLM (BSL+2PLM) and basal + 3% PLM (BSL + 3PLM). Feed and drinking water were present at all times. Parameters measured were ammonia concentration, dry matter excreta, hen day production, total egg mass, feed intake, FCR, dry matter digestibility, and quality of 14-days-stored eggs. A completely randomized design with 4 experimental diets and 5 replications was used. Data collected from this study were analyzed by using analysis of variance and tested with the Tukey test. The addition of peppermint leaf meal reduced ammonia production and increases dry matter excreta, total egg mass production, and dry matter digestibility. The Haugh unit, yolk height, and albumen height were improved when the eggs were kept for 14 days at room temperature. The addition of peppermint leaves meal decreased the mass loss of 14 days-stored eggs. In conclusion, supplementation of diets with peppermint leaf meal decreased ammonia concentration and watery excreta and increased the quality of eggs stored for 14 days at room temperature.

INFLUENCE OF THE SPECTR OF THE LIGHT DURING MEAT-EGGING PULLET REARING ON THE PRODUCTIVE INDICATORS OF THE ADULT POULTRY

One of the insufficiently studied issues in the during of replacement young stock hens young meat-and-egg chickens rearing is the determination of rational parameters of light programs for them. Proceeding from this, research was conducted at the SPRS NAAS to study the effect of the light spectrum in the poultry house during the rearing of replacement young stock of Birkovskiy meat-and-egg chickens on the results of its rearing and the productive indicators of adult birds. 6 groups of Birkovskiy meat-and-egg day-old chicks were formed, during the cultivation of which, respectively, LED lamps (LED) of cold white (4500 K), warm white (3000 K), green, blue and red light, as well as standardized incandescent lamps were used. (IL). At the age of 18 weeks, conditioned chicks were transferred to the poultry house for adult birds, where all of their groups were kept under warm white light (3000 K) with LED. It was found that the replacement young stock grown under green and cold white light (4500 K) at the age of 18 weeks had an advantage in live weight of 78-116 g (P≤0.05) compared to those grown under red light or LED or warm white IL light (2700 K). There were no other statistically significant differences in the main indicators of rearing young stock under light sources with different spectra. The rearing young reared under green and blue light later had a 1.6-1.9 g greater egg mass (P≤0.05) compared to those grown under warm white light LED (3000 K) or IL (2700 K), however, was inferior in egg production and total egg mass yield per initial laying hen to young animals that were grown under cold white (4500 K) light. There were no statistically significant differences between the groups that were grown under the light of different spectra in terms of the yield of hatching eggs and the main indicators of their incubation.

تأثير استبدال مستويات مختلفة من كسبة السمسم كمصدر بروتيني محل كسبة فول الصويا على الأداء الإنتاجي والتناسلي لطائر السمان البياض

أجريت الدراسة في حقل الطيور الداجنة التابع لقسم الإنتاج الحيواني/ كلية الزراعة والغابات/ جامعة الموصل للفترة من 2020/ 2/ 18 ولغاية 2020/ 4/ 13. هدفت التجربة لدراسة تأثير استبدال مستويات مختلفة من كسبة السمسم (SSM) كمصدر بروتيني محل كسبة فول الصويا (SBM) على الأداء الإنتاجي والتناسلي لطائر السمان البياض، استخدم فيها 360 طائر سمان (240 أنثى و120 ذكر) بعمر 49 يوم وزعت عشوائياً إلى خمسة معاملات، كل معاملة ثمانية مكررات وبواقع 9 طيور في كل مكرر (6 إناث و3 ذكور) وكانت المعاملات كالآتي: الأولى سيطرة (كسبة السمسم صفر%)، الثانية والثالثة والرابعة والخامسة تم استبدال كسبة السمسم محل كسبة فول الصويا بالنسب (25، 50، 75 و100)% على التوالي، حيث كان العلف والماء متوفر بصورة حرة طيلة فترة التجربة البالغة 8 أسابيع. أظهرت نتائج التحليل الإحصائي وجود تدهور معنوي بمستوى (α≤0.05 ) في المعاملة الخامسة (كسبة السمسم 100%) مقارنةً بالسيطرة وباقي المعاملات في عدد البيض الكلي، معدل وزن البيضة، كتلة البيض الكلية، نسبة إنتاج البيض Hen day egg production (%H.D)، كمية العلف المستهلك الكلي، معامل التحويل الغذائي، نسبة الخصوبة، نسبة الفقس من البيض الكلي، معدل وزن الأفراخ الفاقسة وارتفاع معنوي في نسبة الهلاكات الجنينية. كما بينت النتائج وجود انخفاض معنوي بمستوى (P≤0.05) في كمية العلف المستهلك الكلي للمعاملة الرابعة (كسبة السمسم 75%) مقارنةً بالسيطرة، في حين لم يلاحظ وجود اي فروقات معنوية لباقي معاملات الاستبدال في جميع الصفات المدروسة. أظهرت نتائج هذه الدراسة إمكانية استخدام كسبة السمسم كمصدر بروتيني بنسبة (75%) محل كسبة فول الصويا في علائق طائر السمان البياض.

Molecular and Biological Characterization of Haemaphysalis Leachi (Acari: Ixodidae) in Nigeria West Africa

Abstract Ticks constitute a serious threat to the wellbeing of humans and other animals. The accurate identification of ticks is paramount in epidemiological investigations. Genetic markers have been identified and used to overcome the limitations of phenotypic identification of ticks. In this study, the cytochrome c oxidase 1 (Cox1) gene was amplified and sequenced for the identification of Haemaphysalis leachi, the putative vector of Babesia rossi in Nigeria. Amplification was successful in 34 out of 39 (87 %) ticks collected from dogs in three Nigerian states with sequence homology of 99 % to H. leachi in Genbank (GenBank: MN663156.1). Maximum Likelihood phylogenetic analysis showed significant grouping of H. leachi sequences in independent monophyletic subclade with a bootstrap value of 100 %. Genetic distance analysis of H. leachi identified in this study indicated a very low level of intraspecific diversity (0.016 %) compared to 0.150—0.190 % interspecific distance to other Haemaphysalis species. The number of eggs laid by engorged female ticks maintained in the laboratory ranged from 885 to 2190 and was proportional to the ticks’ initial weight. The mean value of other biological parameters; female engorgement weight, pre-oviposition period, oviposition period, total egg mass, egg size, efficiency rates of female ticks in converting their food reservoir to eggs and incubation period are, 147.5 mg, 7.8 days, 13.2 days, 59.5 mg, 485.5 × 348.7 µm, 41.2 % and 26.2 days, respectively. This study reports the first molecular identification of H. leachi in Nigeria.

Effects of using processed barley and supplemented multi-enzymes in laying hen rations on egg production, egg quality, and egg fatty acids

In this study, we have observed different technological processes, which are commonly used in poultry production. Rations contained different amounts of barley and multi-enzyme, egg weight, egg mass, egg yield, feed intake, egg weight. The rations of the control groups were as follows: 0% barley (based of corn) (K), 15% untreated barley (A1), 15% pellet barley (A2), 15% flaked barley (A3), 30% untreated barley (A4), 30% pelleted barley (A5), 30% flaked barley (A6), 30% untreated barley + enzyme (0. 025%) (A7). In the research, 64 brown laying hens ATAK-S for 36 weeks were divided into 8 different treatments for egg hens. Thirty-week-old laying hens were divided into 8 groups of 8 animals each with a similar live weight. Each treatment consisted of 8 animals in individual cages. Animals were completely randomly determined, grown in individual cages, and kept under a 16:8 h light: dark lighting period. Feed and water were given as ad-libitum. The highest egg weight was obtained from chickens fed with A2 group (62.98 g), and those chickens fed with A1 group (56.45 g) showed lowest egg weight (p ≤ 0.01) In terms of total egg mass, the statistical differences between the experimental groups were very important, but A2 had the highest value and A4 group had the highest value. (p ≤ 0.01). When considering the average feed consumption, feed consumption of A2 fed chickens was higher than the other groups (p ≤ 0.001). Feed consumption of chickens fed A4 and A7 groups were significantly less than that of A1 group and K group feed consuming groups (p ≤ 0.001). There was no significant difference in mean egg yield between treatments. When egg weight average was examined, it was found that egg weight was higher than A4 group's weight ratios when A7 group's added weighted ratio was considered (p ≤ 0.01). When we examined the omega- 6 (n- 6) and omega-3 (n- 3) fatty acids in the trial, linolelaidic acid, one of the omega 6 fatty acids, was found to differ between treatments (p ≤ 0.05). The lowest value for linolelaidic acid ranged from 0.022 in A3 group, while the highest value was 0.046 in A2 group.

Nondestructive Sampling for Spotted Lanternfly (Hemiptera: Fulgoridae) Egg Masses in Woodlands Based on Fixed-Radius Plots.

A nondestructive sampling method was developed for Lycorma delicatula egg masses based on fixed-radius plot (100 m2) in 2020. All trees >1.0 cm DBH (diameter at breast height, 1.37 m in height) on each plot were visually inspected from the ground 4 m from the tree with binoculars. Egg masses found on trees were separated into six within-tree positions (lower trunk, middle trunk, upper trunk, first branch, second branch, above second branch) and recorded by cardinal directions, whereas those laid on shrubs/vines and stones were recorded without such separation. In total, 146 trees were inventoried at 28 plots over seven study sites (four plots per site). Egg masses were found on 19 tree species plus summer grape (Vitis aestivalis) and stone. Of the 421 total egg masses recorded, 31.1% were on Norway maple (Acer platanoides), followed by tree-of-heaven (Ailanthus altissima; 14.7%), black birch (Betula lenta; 12.6%), tuliptree (Liriodendron tulipifera; 11.9%), and American beech (Fagus grandifolia; 10.2%). Egg mass density per tree was positively correlated with tree diameter, and egg mass density per plot was positively correlated with plot basal area. Egg mass density after conversion ranged from 600 to 3,930 eggs masses/ha with no significant difference among study sites. Cardinal direction had no effect; however, significantly more egg masses were found on the first branches and upper trunks than other within-tree positions. Overall, branches were better than trunks in predicting egg mass number for the tree. The role of distance and late season adult aggregation on oviposition substrate selection are discussed.

Albumen Quality of Fresh and Stored Table Eggs: Hen Genotype as a Further Chance for Consumer Choice.

Simple SummaryConsumer interest in food products and their origins is increasing. Knowledge of egg production and quality of purebred hens during the productive period is required for a niche market sustaining and encouraging biodiversity and the peculiarities of the products that consumers can appreciate. Egg production and quality of the eggshell and albumen in fresh and stored eggs of two Italian dual-purpose purebreds (Ermellinata di Rovigo (ER); Robusta maculata (RM)) and two hybrid genotypes (Hy-Line Brown (HB); Hy-Line White (HW)) reared outdoors were compared throughout the laying period. RM breed (brown eggshell) showed fresh and stored eggs with a good eggshell thickness, and Haugh Units (HU) quite stable along the production period; RM total egg mass was lower than ER (light brown eggshell) which showed fresh and stored eggs with more variable HU, due also to a possible effect of lower eggshell thickness and pigmentation, and shape index. The hybrids produced a higher total egg mass than the purebreds and showed an intermediate variation of the egg quality, with HU higher than those of ER and RM only in 1 d eggs, but not in stored eggs.The quality of fresh (1 d) and stored (7–14–21 d, 21 °C) eggs was studied in Italian dual-purpose breeds (Ermellinata di Rovigo (ER), Robusta maculata (RM)) and hybrids (Hy-Line Brown (HB), Hy-Line White36 (HW)), reared outdoors (4 m2/bird) and fed commercial feed. The eggs were analyzed at 4 ages, throughout different seasonal environmental conditions, from summer (31, 35 weeks; 25 °C) until autumn (39, 43 weeks, 15 °C). Each genotype showed significant (p < 0.01) changes in egg quality. In 1 d eggs, the eggshell thickness changed in RM and HW (quadratic), decreased linearly in ER; Haugh Units (HU) changed (ER–cubic) and decreased (hybrids-linear). In 7 d and 14 d eggs, HU linearly (p < 0.01) decreased, except in RM. In 21 d eggs, HU (ER linear decrease; HB, HW quadratic) changed. Significant negative correlations between albumen pH and height were seen in ER (at 1 d, 14 d, 21 d) and HW (at each storage time) eggs, and in RM and HB only in 1 d eggs. RM showed a quite stable albumen quality and a lower total egg mass than ER which showed a more variable albumen quality, due also to a lower eggshell thickness and shape index. The hybrids produced a higher total egg mass than the purebreds and showed an intermediate variation of the egg quality, with an albumen quality higher than those of ER and RM only in 1 d egg, as a result of a higher albumen weight.

Heterosis for egg production in native by exotic by inbred chicken crosses

Inbred lines generated from the native and exotic chickens were compared with their F1 and backcross populations for a range of short term egg production traits. The experimental birds were brooded for 8 weeks and raised on a deep litter pens from 8 to 40 weeks of age. Age at first eggs were longer in the crossbred groups and the delay was mostly caused by the dominant genes from the exotic parents. Highly significant (P&gt;0.01) heterosis were obtained by the crossbred groups in hen day rate and total egg mass respectively. The heterosis observed in the crossbred groups for egg weight was low and mostly non significant. the backcross groups recorded residual heterosis in egg production traits ( hen day rate, total egg mass and egg weight) and the magnitude was higher in the exotic than the native backcrosses. The results further indicate that the egg production performance of the crossbred groups were mostly influenced by maternal, sex linked, dominance and epistatic gene effects. It was suggested that the egg production potential of the native chicken could be improved further by cross mating-selected native and exotic backcross groups. This should be followed by crisscrossing.

The reproductive value of large females: consequences of shifts in demographic structure for population reproductive potential in Chinook salmon

While conservation and fisheries management are often concerned with changes in population abundance and distribution, shifts in population age–size structure are commonly observed in response to human and environmental stressors. Chinook salmon (Oncorhynchus tshawytscha) have experienced widespread declines in mean age and size throughout their North American range. We investigated the consequences of declines in body size for spawner reproductive potential in terms of total egg mass per female. Our case study is the Yukon River where Chinook salmon have supported subsistence, commercial, and recreational fisheries. Using historical observations on individual body size from throughout the Yukon River and the relationship between female size and total egg mass from the Canadian portion, we estimate a decline in average female reproductive potential of 24%–35% since the 1970s. Because spawner abundances and the population sex ratio have not shown clear trends over time, our results suggest a reduced total population reproductive potential. Changes in spawner quality should be considered when developing management reference points, and conservation of population demographic structure may be necessary to sustain productive Chinook salmon systems.

EFFECT OF ADDING THYMUS VULGARIS POWDER TO RATION ON REPRODUCTIVE PERFORMANCE OF QUAIL

This study was conducted in the Poultry farm of Animal production Dept. College of Agriculture and Forestry, Mosul University in order to investigate the effect of adding Thymus vulgaris Powder to the diets on productive performance and Reproductive for laying quail. One hundred forty four unsexed quail Coturnix coturnix 90 day old were randomly distributed into four treatments with four replicate in each replicate nine birds 6 female and 3 male, The treatments were as follows: first basal diet without addition as (control). Second, third and fourth treatments basal diet and addition of Thymus vulgaris Powder in 0.5, 1, 1.5 % respectively. Feed and water was ad libitum. Statistical analysis of data showed significant improvement (p≤0.05) in total egg number, average egg weight, hen day production, feed conversion ratio(g feed: g eggs) for treatments third and forth as compared with control. Also significant increase in daily and total egg mass in treatments second, third and forth as compared with control. No significant difference in live body weight, average body weight gain, feed consumption , feed conversion ratio (g feed: egg), mortality rate, fertility percentage, hatchability percentage from total and fertile eggs and embryo mortality

Effect of the Ration Form on Productive Performance of Three Japanese Quail Breeds

تم تنفيذ الدراسة على (720) فرخا من ثلاث سلالات من السمان الياباني هي الصحراوي والأسود والأبيض لبيان تأثير السلالة وثلاثة أشكال للعليقة هي المجروش والمحبب والمفتت وبواقع ثلاث معاملات وبأربع مكررات لكل سلالة خلال مرحلة النمو (1- 35 يوما)، و324 أنثى من نفس السلالات بواقع ثلاث معاملات وبأربع مكررات لكل سلالة خلال مرحلة إنتاج البيض (42- 101 يوما). أظهرت نتائج البحث وجود فروقات معنوية (P≤0.05) لتأثير السلالة في وزن الجسم الحي والزيادة الوزنية ومعامل تحويل العلف (غم علف: غم زيادة وزنية) و(غم علف: غم ذبيحة) ووزن الذبيحة خلال مرحلة النمو، وفي وزن البيضة خلال مرحلة إنتاج البيض. أما بالنسبة لتأثير شكل العليقة فقد اتضح وجود فروقات معنوية (P≤0.05) لصفات وزن الجسم الحي والزيادة الوزنية ومعامل تحويل العلف (غم علف: غم زيادة وزنية) و(غم علف: غم ذبيحة) ووزن الذبيحة خلال مرحلة النمو، وفي وزن البيضة وكتلة البيض الكلية خلال مرحلة إنتاج البيض. أما تأثير التداخل بين السلالة وشكل العليقة فقد أوضحت نتائج التحليل الإحصائي وجود فروقات معنوية (P≤0.05) في وزن الجسم الحي والزيادة الوزنية ومعامل تحويل العلف (غم علف: غم زيادة وزنية) و(غم علف: غم ذبيحة) ووزن الذبيحة ونسبة التصافي خلال مرحلة النمو، وفي نسبة القشرة ووزن البيضة وعدد البيض الكلي وكتلة البيض الكلية وتركيز الالبومين خلال مرحلة إنتاج البيض. أما ما يخص الحسابات الاقتصادية فقد أظهرت النتائج حصول سلالة السمان الصحراوي على أفضل ربح (دينار عراقي/ كغم وزن حي) خلال مرحلة النمو، بينما حصلت سلالة السمان الأبيض على أفضل ربح (دينار عراقي/ كغم بيض) خلال مرحلة إنتاج البيض. أما أفضل ربح نتيجة تأثير شكل العليقة فقد كان من نصيب العلف المحبب خلال مرحلتي النمو وإنتاج البيض. أما أفضل ربح لمعاملات تداخل السلالة وشكل العليقة فقد كان لتداخل سلالة السمان الصحراوي مع العلف المحبب خلال مرحلة النمو، وتداخل سلالة السمان الأبيض مع العلف المحبب خلال مرحلة إنتاج البيض.

Effects of Physiological Condition on Aspects of Repeat Spawning in Female Steelhead Reconditioned in Captivity

AbstractPhysiological condition (hereafter shortened to “condition”) influences survival, spawning schedules, and reproductive effort in salmonids. In iteroparous females, the effects of first spawning on condition could result in trade‐offs with future reproduction, mediated by postspawning survival, repeat spawning schedule (i.e., consecutive or skip spawning), or reproductive effort. However, which aspects of condition affect these outcomes and when they are sensitive to condition are not well understood. These issues were examined in highly energy‐depleted hatchery‐origin female summer steelhead Oncorhynchus mykiss that were undergoing postspawning reconditioning in captivity. Measures of condition and reproductive characteristics (i.e., fecundity, egg size, and total egg mass [TEM]) at first spawning were examined for their effects on postspawning survival and future spawning schedules, and condition was tracked during reconditioning to examine effects on reproductive characteristics at repeat spawning. The levels of plasma osmolality and triglycerides measured at first spawning were positively correlated with survival probability, suggesting that survival depends on the ability to maintain homeostasis and access stored energy. Surprisingly, size‐standardized TEM measured at first spawning was positively correlated with the probability of consecutive spawning, providing no support for the hypothesized trade‐off between current and future reproduction. This finding instead suggests that both first‐spawning reproductive effort and consecutive spawning may be influenced by condition at earlier points. Plasma triglycerides and growth rates at sampling points 10–20 weeks after first spawning were strongly correlated with size‐standardized egg size and TEM at consecutive spawning, suggesting that reproductive effort and its allocation to egg size and fecundity depend on energetic status during early oogenesis. These results indicate that condition influences survival, repeat spawning schedules, and reproductive characteristics in female steelhead up to a year or more before repeat spawning. If more broadly applicable, these relationships could provide insight into the mechanisms that link environmental conditions with reproductive characteristics in salmonids and other species.

Caracterization of glutathione S-transferase of Dermacantor marginatus and effect of the recombinant antigen as a potential anti-tick vaccine

Dermacentor marginatus is one of the main tick species in northwestern China, and is a vector of various tick-borne pathogens. Tick control method largely depends on chemical agents, but the disadvantages of using such approach would cause environmental damage and the risk of developing tick resistance to acaricides. Vaccination of tick protective antigen is an eco-friendly approach which is an alternative and promising method to mitigate tick infestation in livestock. In the study, a mu-class glutathione S-transferase (GST) sequence of D. marginatus was cloned and the recombinant protein (rDmGST) was expressed. Transcriptional level of the GST was measured together with native GST activity of the tick. Finally, A vaccine trial on rabbits against D. marginatus was proceeded to evaluate the anti-tick effect of rDmGST. Results reveled that the CDs of the D. margiantus glutathione S-transferase mu 1 gene has 669 base pair nucleotide sequence encoding a 223 amino acid. The deduced GST protein sequence had over 95 % similarity with that of D. variabilis. The rDmGST was efficiently expressed soluble and purified by His trap affinity chromatography. Enzyme activity of native GST and transcriptional profiles of the GST showed up-regulation in different stages and organs of D. marginaus during blood feeding. Polyclonal antibody reacted with rDmGST in Western blotting. Tick challenge on rDmGST inoculated rabbits showed reductions in adult female engorgement rate, total egg mass and egg hatching rate with an overall vaccine efficacy of 43.69 %. The results of the experiment indicated the GST has potential value to be an effective protective antigen of D. marginatus.

Xylanase and β-glucanase in diets for Japanese laying quails

The rations of monogastric animals in Brazil are composed of corn and soybean meal. The main obstacles of grains use in diets are related to the presence of non-starch polysaccharides and the increase in viscosity. Thus, it is important to study non-conventional ingredients and the use of additives, such as enzymes in animal feed. The objective of this study was to evaluate the productivity and metabolism of Japanese laying quails fed with corn or sorghum feeds containing or not xylanase and β-glucanase. The experimental design was completely randomized in a 2x2 factorial scheme, with four treatments, with five replicates and seven birds each, to 140 animals. The treatments were: 1) ration based on soybean meal and maize (RSMM); 2) RSMM with enzymes; 3) ration based on soybean meal and sorghum (RSMS) and 4) RSMS with enzymes. The evaluated variables were: zootechnical performance; metabolizable rations and excreta; quality and oxidative process of eggs; biometrics of organs and serum biochemistry. There was no significant interaction between the factors (ingredients x enzymes) for all evaluated characteristics. The rations did not cause changes in the productive variables, metabolizable, egg quality, biometry of the gastrointestinal tract organs and femur of Japanese laying quails. The total egg mass was higher in the treatments with enzymatic use. Serum calcium and phosphate concentrations were higher in the RSMM and RSMM with enzymes, however, the Ca:P ratios remained, indicating a metabolic normality condition in the birds.

Energy partitioning by broiler breeder hens in conventional daily-restricted feeding and precision feeding systems

An empirical linear mixed model was derived to describe metabolizable energy (ME) partitioning in broiler breeder hens. Its coefficients described ME used for total heat production (HP), growth (ADG), and egg mass (EM). A total of 480 Ross 308 hens were randomly and equally assigned to 2 treatments: precision feeding (PF) and conventional daily-restricted feeding (CON) from 23 to 34 wk of age. The PF system allowed birds to enter feeding stations voluntarily at any time, weighed them, and provided access to feed for 60 s if their BW was less than the breeder-recommended target BW. The CON birds were fed daily each morning. Energetic efficiency of hens was evaluated using residual feed intake (RFI), defined as the difference between observed and predicted ME intake (MEI). The energy partitioning model predicted (P < 0.05): MEI = A × BW0.67 + 1.75 × ADG + 0.75 × EM + ɛ. The coefficient A, a vector of age-specific HP, was 142 kcal/kg0.67/d; the energy requirement for growth and EM was 1.75 and 0.75 kcal/g, respectively. For the CON and the PF hens, respectively, MEI was 366 and 354 kcal/d (P = 0.006); RFI was –5.9 and 6.7 kcal/d (P = 0.009); HP% was 85.5 and 87.7 (P < 0.001); hen-day egg production (HDEP) was 65.5 and 55.2% (P < 0.001). Although the CON hens had higher MEI, the model predicted lower HP%; thus, CON hens had more nutrients available for egg production, increased egg production, and were more energetically efficient than the PF hens. The decreased egg production by the PF hens was likely due to these hens receiving production-related feed increases after an egg was laid. However, feed allocation increases for the CON hens resulted in increasing MEI for all CON hens at the same time. Therefore, the PF hens had lower MEI and lower HDEP than the CON hens.