Viability and hatchability of brine shrimp Artemia franciscana cysts after passing through the digestive system of eared grebes Podiceps nigricollis

Brine shrimp Artemia franciscana provide food for many migrating and staging birds that spend summer and fall on Great Salt Lake,Utah,USA.Artemia produce live young and cysts(hard-walled eggs);these cysts are commercially harvested on Great Salt Lake and support a large industry in Utah.It is unclear the impact that millions of hungry birds have on the Artemia population in the lake.To help assess that,this study evaluated cyst viability(percentage of cysts that contain an embryo)and hatchability(percent of cysts that hatch)from cysts that had passed through the digestive tract of eared grebes Podiceps nigricollis and cysts obtained directly from Great Salt Lake at the same site where each grebe was collected.Hatchability was significantly higher for cysts collected from the water column(19%)than from the stomach(0.3%)or intestines(3%)of eared grebes.Viability also was significantly different for cysts collected from the water column(29%),stomach(0.7%),and intestines(5%).These results indicate that eared grebes nutritionally benefit from eating cysts and that they may be an important food source for grebes in late fall after the adult population of Artemia dies off due to the water becoming too cold.Also,enough cysts survive their passage through the digestive system that grebes can vector hatchable cysts to other waterbodies.

Fecundity and egg hatchability of Dastarcus helophoroides adults fed on different types of artificial diets

Both fecundities and egg hatchabilities were compared among three populations of Dastarcus helophoroides Fairmaire adults（Coleoptera： Bothrideridae） fed on three types of artificial diets（Diet of formula 1 composed of silkworm pupa powder, dried yeast powder,sucrose, peptone, egg yolk powder and poplar branch powder. Diet of formula 2 composed of silkworm pupa powder, dried yeast powder, sucrose, egg yolk powder,poplar branch powder, cricket powder, benzoic acid and distilled water. Diet of formula 3 composed of pine bark powder and Monochamus alternatus larva powder）. for90 days. The three diets showed no significant difference regarding the average number of eggs deposited by all D. helophoroides females（16622.3–23874.7）; the average number of eggs per female（1278.6–1836.5）; and the average number of eggs per female per day（14.2–20.4）.The number of eggs one cluster contained mainly（82.06–82.66 %） lied in 1–100 eggs, and the average number of eggs per cluster ranged from 61.7 to 63.1. In the first 10-day period, the number of eggs deposited by all females fed on formula 1 was significantly larger than that on formula 3. The eggs deposited in the last four 10-day periods were more than in the former five 10-day periods,on formula 3. There were no significant differences in hatchability of total eggs among the three artificial diets,and the average corrected egg hatchability ranged from82.85 to 84.78 %. No significant differences in the adult mortality and mean weight gain of D. helophoroides were found after feeding on three artificial diets. Our results suggest that D. helophoroides adults were not specialized on the diet, and the diet types might have little effect on fecundity and egg hatchability in D. helophoroides, as long as sufficient nutrition was supplied.

Comparative Laying Performance, Egg Quality, Fertility and Hatchability of Guinea Fowl with Tilili, Horro and Potchefstroom Koekoek Chicken Breeds

A study was conducted to compare laying performance, fertility, hatchability, and egg quality of guinea fowl (GF) with Horro (HR) and Tilili (TL) local chicken and Potchefstroom Koekoek (PK) exotic chicken. Forty five layers from each genotype and 6 cocks from each chicken genotype and 9 cocks from GF were used in 3 replications in a completely randomized design. Commercial layer feed was used ad libitum for the study that lasted 29 weeks. Daily DM intake per hen was 85, 114, 103 and 137 g (SEM = 3.1) for GF, HR, TL and PK, respectively, and was in the order of GF < TL < HR < PK. Final body weight of hens was highest for PK (2490 g), intermediate for HR (1983 g) and lowest for TL (1671 g) and GF (1641 g). Egg number per production week followed a similar trend like that of DM intake and was 71, 101, 75 and 121 (SEM = 0.5) for GF, HR, TL and PK, respectively. Both fertility and hatchability of fertile eggs for GF were 57%, which were lower than the mean of chicken genotypes by 41% and 34%, respectively. Embryonic mortality was higher for GF (early, middle and late was 15.8%, 10.0%. and 17.4% respectively) compared to chicken genotypes. Chick weight was highest for PK, intermediate for HR and TL and lowest for GF;while chick length was in the order of PK > HR > TL > GF. Average egg weight was higher for PK eggs (46.4 g), intermediate for HR (43.5 g) and TL (42.3 g), and lowest for GF (35.9 g). Eggshell weight and thickness were higher for GF than chicken genotypes. Haugh unit was similar among genotypes. Such differences among poultry genotypes could be reflection of previous selection and breeding interventions, which are apparently more in chicken genotypes than GF. A possible more stressful condition of the confined environment for GF versus chicken genotypes could have also contributed to such differences. This study highlighted the need of implementing future selection and breeding schemes to improve the performance of GF and TL birds to the level achieved by other genotypes.

Research on the appropriate way to transfer exogenous substances into chicken embryos

In biological research, chicken embryos are a classic experimental model for the exploration of the embryonic development and cell differentiation. Transferring exogenous substances into chicken embryos for producing medical antibodies has been widely used in the production practice. However, there are few studies about the effect of the different injection site and dosage on chicken embryos. The aim of this study was to explore the effects of different injection sites and dosages on chicken embryo hatching rate and development, so as to provide a basis for further studies using the chicken embryo model. Freshly laid eggs （Rugao yellow chicken） were injected with different doses of saline at the tip, equatorial plane and the blunt end of the egg shell, respectively. Egg hatching rate was recorded and compared among injection sites and different doses. A trypan blue stain was also injected at the aforementioned sites and the growth of chicken embryos was observed. The SPSS （statistical package for the social science） software was used to analyze the relationship between the chicken eggs hatching rate and the different injection sites or the different dosages. The experimental results showed that there were significant differences on egg hatching rates among the different injection sites and doses （P〈0.05）. The hatchability of the blunt end injection group was significantly higher than that of the other two sites. The egg hatching rate decreased with increased saline doses. The egg hatching rate of the 100 pL saline injection group was higher than the 200 and 300 μL dosage groups. Ultimately, we suggest that the optimal chicken embryo injection process is during early development, at the blunt end site with a dose less than 100 μL to minimize damage to the egg.

Egg investment strategies adopted by a desertic passerine, the Saxaul Sparrow(Passer ammodendri)

Background:As one of the reproductive strategies adopted by bird species,variation in investment in egg production and its influencing factors are important and well-studied subjects.Intraclutch changes in egg size associated with laying order may reflect a strategy of"brood survival"or"brood reduction"adopted by female birds in different situations.Methods:We conducted field studies on the breeding parameters of the Saxaul Sparrow(Passer ammodendri)in Gansu Province,China from 2010 to 2017,to clarify the factors affecting the egg investment and reproductive performance of this passerine species.Results:Our results revealed significant differences in clutch size,egg size and the fledging rate between the first and second brood of Saxaul Sparrows and suggested that this typical desert species allocates more breeding resources to the more favourable second brood period,leading to greater reproductive output.Female body size presented a positive relationship with egg size,and male body size presented positive relationships with clutch size and hatchability.The females that started their clutches later laid more eggs,and hatchability and the fledging rate also increased with a later laying date in the first brood period.With successive eggs laid within the 5-egg clutches(the most frequent clutch size),egg size increased for the first three eggs and then significantly decreased.Conclusions:Our results indicate that female Saxaul Sparrows increased egg investment because of good quality of paired males and good environmental conditions.The intraclutch variation of egg size suggests that this species inhabiting an arid environment adopts a"brood reduction"strategy.

Effects of Ginger (Zingiber officinale) Rhizomes Essential Oil on Some Reproductive Parameters in Laying Japanese Quail (Coturnix coturnix japonica)

To assess the effect of ginger rhizomes essential oil on some reproductive parameters of laying birds, 80 female Japanese quails (Coturnix coturnix japonica) aged 3 weeks and weighing between 120 - 130 g were randomly assigned into 4 dietary treatment groups in a completely randomized design. From 3 till 13 weeks, birds in group 1 (control) received distilled water orally (100 μl/kg body weight), while the other three test groups during the same period, received respectively by gavage 50, 100 and 150 μl of ginger roots essential oil per kg body weight. At 11 weeks old, eight birds per group in each treatment were randomly selected and slaughtered, blood samples collected for analysis. On the other hand, the remaining females were maintained 3 with one untreated male in identical boxes per treatment, for fertility assessment, eggs characteristics and hatchability traits. Throughout the experiment, biochemical parameters, eggs characteristics, fertility and hatchability traits were analyzed. No significant change (p > 0.05) was observed during the experimental period for body and relative ovary weights. Contrary, the relative uterus weight significantly increased (p < 0.05) in dose-dependent manner. The level of serum total proteins, LH, FSH and estradiol significantly increased (p < 0.05) in a dose-dependent manner. Also, fertility, hatchability of fertile eggs, total hatchability and chick’s weight significantly increased (p < 0.05) in birds received 100 and 150 μl/kg b.w compared to those of control group. On the other hand, embryonic mortality decreased significantly (p < 0.05) whatever the ginger rhizomes essential oil dose. It was concluded that ginger rhizomes essential oil enhances bird reproductive performances, proteins and reproductive hormone levels and hatchability traits in treated female quails.

Effect of Combined Vitamin C and Vitamin E Supplementation on Reproductive Performance and Hatching Rate in Japanese Laying Quail

This study was carried out to evaluate the effect of vitE(Vitamin E)supplementation in combination with vitC(Vitamin C)on reproductive performance and hatching rate of Japanese quail at the age of 59-114 days.A total of 132 laying quails were arranged in a completely randomized design with 3 treatments and 4 replicates,each replicate being 9 female quails and 2 male quails at 59 days of age.The experimental treatments were as follows:control fed the basal diet(KPCS),E125C75 including KPCS supplemented with 125 mg vitE/kg feed combined with 75 mg vitC/kg feed and E125C125 including KPCS supplemented 125 mg vitE/kg feed combined with 125 mg vitC/kg feed.Research results showed that the highest WG(Weight Gain)was in E125C125(30.32 g)and lowest in E125C75(17.37 g).There were no statistically significant differences between treatments in terms of laying rate,feed conversion ratio,egg mass and egg weight.However,hatching rate and bodyweight of quails at 1 day of age were significantly different between treatments,the highest was E125C125(74.37%and 7.43 g),followed by E125C75(70.02%and 7.03 g)and the lowest was control(65.89%and 6.82 g).It can be concluded that E125C125 not only improved laying rate but also increased hatching rate and bodyweight of quail chick.