人工诱导池养3+龄鲥鱼性腺发育的初步试验与探讨

通过模似鲥鱼性腺发育的自然生态条件和埋植 LHRH-A 和 Testosterone 缓释放颗粒激素,诱导池养3~+龄鲥鱼性腺发育季至第1期,成熟系数达0.9%。试验摸索出麻醉操作鲥鱼不死的有效方法。对今后鲥鱼全人工繁殖的前景及有关问题进行了探讨.     

卤鸭肝肫软罐头的研制

本产品以鸭肝肫为原料，经卤制、切片、灭菌等加工工艺制成鸭肝肫软罐头，该产品开袋即食，营养丰富，风味独特。     

Involvement of Bacillus licheniformis and Micrococcus kristinae During Ripening of Salt Fermented Indian Shad (Tenualosa ilisha)

ABSTRACT

“Lona ilish” is a salt fermented fish product prepared exclusively from fatty Indian shad (Tenualosa ilisha). Despite the presence of salt and metals coming from the container used for fermentation, rancidity is not observed as long as the products are kept immersed in the fermenting brine. To understand the technical principles of this indigenous preservation method, the traditional preparation was followed along with analyses of chemical and microbiological changes. The biochemical and microbiological changes were followed at 15 day intervals during the fermentation period of 150 days. From the 45th day of fermentation onwards, the microbial flora in the product was composed of only two species, tentatively identified as Bacillus licheniformis and Micrococcus kristinae. Because Bacillus licheniformis showed some atypical biochemical reactions, it was tentatively identified as Bacillus licheniformis var. III. These two bacterial species either singly or collectively were involved in the fermentation process.     

Effect of intermittent feeding and oat hulls to improve phytase efficacy and digestive function in broiler chickens

1. Two trials were carried out to investigate the impact of intermittent feeding and oat hulls as methods to stimulate the anterior digestive tract in broiler chickens.

2. In Trial 1, 7-d-old broilers were placed 4 per cage in 48 cages and fed either ad libitum or intermittently on a diet with 50 g/kg of either oat hulls or cellulose, with or without 1000 FTU phytase, in a 2 × 2 × 2 factorial arrangement. Ad libitum fed birds had two 4-h dark periods with 1-h light in between, while intermittently fed birds in addition had restricted access to feed through four 1 h feeding bouts.

3. In Trial 2, 144 broiler chickens were divided amongst 12 pens which were intermittently fed on the same diets as in Trial 1 in a 2 × 2 factorial arrangement. At 34 d of age, after 16 h feed withdrawal, birds were fed for 1 h, followed by dissection of 4 birds per treatment every hour for 9 h. Contents from different segments of the digestive tract were collected quantitatively to assess dry matter (DM) and starch flow.

4. In Trial 1, phytase improved performance and nutrient availability, while oat hulls and intermittent feeding improved some measures of nutrient availability. Intermittent feeding augmented the effect of phytase on myo-inositol hexakisphosphate (IP6) degradation in the anterior digestive tract.

5. In Trial 2, birds filled up their crop and slowly passed these contents on to lower segments of the digestive tract. Already 1 h after commencement of feeding, the entire length of the small intestine was filled with DM, and no significant changes in DM content were observed before 4–5 h later, when the small intestine gradually became emptied. The tendency for a higher initial load of DM and starch in birds without oat hulls seems to support the hypothesis that one important function of the gizzard is feed-flow regulation.

6. In conclusion, the anterior digestive tract seems to have an important regulative function in broiler chickens when stimulated by intermittent feeding or structural components. More research is needed in order to elucidate the role of the crop and gizzard for phytase function.     

福建省东山岛西埔湾港养斑鰶的繁殖生物学

本文研究了福建省东山岛西埔湾港养斑鰶性腺周期发育、成熟系数周年变化、个体生殖力以及雌雄同体。港养斑鰶能在半封闭式湾内发育成熟而且自然产卵。其卵细胞发育分为6个时相,精巢发育分为6期。卵膜由透明带、外放射带和内放射带组成,内有孔道结构。第4时相中期卵母细胞的内放射带有7～8层纤维状片层。产卵后鞘膜细胞和颗粒细胞分裂增殖变成游走的吞噬细胞。西埔湾港养斑鰶Ⅰ龄鱼初次性成熟,生殖季节从12月下旬至翌年3月下旬,生殖盛期为2月,雌鱼成熟系数高达17.88％。个体绝对生殖力为7575～72621粒,平均 35310粒,系属于分批产卵类型,第1批生殖力大于第2批。     

Threadfin shad impacts phytoplankton and zooplankton community structures in channel catfish ponds

Plankton community structure and chlorophyll a concentration were compared in twelve 0.1 ha earthen ponds co‐stocked with channel catfish (Ictalurus punctatus Rafinesque, 1818) in a multiple‐batch culture (initial biomass=5458 kg ha^?1) and a planktivore, threadfin shad (Dorosoma petenense Güther, 1867; initial biomass=449 kg ha^?1), during the April–November growing season. We used a completely randomized design in a 2 × 2 factorial arrangement to test the planktivore level (presence or absence of threadfin shad) and channel catfish feeding frequency (daily or every third day). Channel catfish were fed a 32% protein feed to apparent satiation on days fed. The presence of threadfin shad affected phytoplankton and zooplankton community structure more than did feeding frequency, and the impact in ponds was more pronounced after 1 July. The numbers of all major groups of zooplankton were lower in ponds with threadfin shad, but were unaffected by the feeding frequency. Chlorophyll a concentration before 1 July was higher in ponds with threadfin shad and unaffected by the feeding frequency, whereas after 1 July it was higher in ponds without threadfin shad and that were fed daily. Phytoplankton community structure after 1 July was dominated by nuisance algal bloom genera of cyanobacteria in ponds without threadfin shad and by Bacillariophyceae in ponds with threadfin shad.     

Dietary overlap and selectivity among silver carp and two native filter feeders in the Wabash River

Silver carp (Hypophthalmichthys molitrix) are a potential threat to native filter feeders and larval fish due to dietary overlap. To test for dietary overlap and selectivity, we collected diet samples from invasive silver carp and two native filter feeders (gizzard shad Dorosoma cepedianum and bigmouth buffalo Ictiobus cyprinellus), and river plankton samples at three sites on the Wabash River during the spring and summer of 2015. Contents of diet items were identified to major group and quantified. Diet proportions were compared among seasons, sites and species. Diet selectivity was calculated using the Manly–Chesson diet selectivity index. The results of our diet analysis showed that silver carp had significantly dissimilar diets among seasons and displayed dietary overlap with native fishes. We did not find a significant difference among sample sites. While silver carp diets overlapped with native fishes, the impact of this possible source of competition requires further study to confirm impacts on native fish abundances and body conditions.     

Whole pearl millet feeding does not impair performance and nutrient digestibility in 28-day-old broiler chickens

The effects of varying inclusion levels of whole grain millet in millet–soya bean-based diets on growth performance, gizzard development, digesta characteristics and nutrient digestion in broiler chicken were investigated. Starter (0–14 days) and grower (15–28 days) broiler chicken diets containing pearl millet at 500 and 540 g/kg diet, respectively, were formulated. The diets comprised of 0%, 20%, 40%, 60%, 80% and 100% of millet incorporated as whole grain. One-day-old unsexed Arbor Acres Plus chicks (n = 540) were allotted to the experimental diets in a completely randomized design with the diets and water provided ad libitum for 28 days. Each treatment was replicated seven times, and each replicate had 12 chicks. Results showed that daily live weight gain and feed conversion ratio of chickens on the whole millet grain diets compared favourably with chicken on the control in both starter and grower phases, while feed intake reduced quadratically (p < .05) with increased whole grain millet levels in the starter phase. Morphological and structural characteristics of the gizzard and small intestine and intestinal digesta pH and viscosity were also unaffected (p > .05) by whole grain millet inclusion levels. However, the weight of intact millet grain in gizzard increased linearly (p < .001) with whole grain millet inclusion in the diets. Dietary whole grain millet inclusion also consistently lowered (p < .05) jejunal and ileal maltase and sucrase activities, but did not influence (p > .05) pancreatic amylase activity. Ileal crude protein and starch digestibility increased, while ileal energy digestibility decreased significantly (p < .05) with whole grain millet inclusion. Whole grain millet inclusion in broiler starter and grower diets up to 500–540 g/kg did not negatively impact on broiler chicken performance.     

鸡肫黄豆软罐头工艺与技术研究

以鸡肫和黄豆为主要原料,以复合蒸煮袋作包装材料,经过预煮、脱气、腌制、封口、杀菌等工序,制得了番茄汁鸡肫黄豆软罐头,确定了最佳生产工艺,并研究了其生产技术条件与营养保健作用。