Feeding Responses of Hatchery-Reared Gilthead Sea Bream (Sparus aurata L.) to a Commercial Diet and Natural Prey Items

Many fish species have evolved feeding mechanisms and behaviours enabling them to feed on specific prey. However, such mechanisms may not be optimal for feeding on commercial-pelleted diets in aquaculture. Gilthead sea bream chew and occasionally eject pellets or parts of pellets from the mouth when feeding on commercial diets. This may result in an increase in nutritional waste from the intensive culture of this species. In this study we examined the prevalence of this food processing behaviour in two sizes of sea bream, feeding on three types of natural prey items in comparison to a commercial pellet, to give an insight into the circumstances in which excess chewing and ejection of food items from the mouth occurred. These included two hard-textured food items (commercial pellet and hard-shelled prey) and two soft-textured food items (larvae and small crustacean). Both sizes of sea bream frequently consumed the soft-textured food types, however large sea bream also frequently consumed hard-textured pellets. Hard-textured food required longer handling times and elicited more chewing and the ejection of food items from the mouth. These results suggest that future investigations on the food processing behaviour and consequent waste when fed commercial diets differing in texture could give an insight into improving diets and feeding efficiency for intensively cultivated gilthead sea bream.     

Is the citrus-like plumage odorant of crested auklets (Aethia cristatella) a defense against lice?

Plumage odors may function as chemical defenses against ectoparasites in birds. We tested this hypothesis for crested auklets (Aethia cristatella), a species of colonial seabird that emits a very strong citrus-like odor from its plumage. This odorant contains known chemical repellents. We evaluated evidence for chemical defense in this species using two approaches. First, we exposed pigeon lice to the volatiles emitted by freshly plucked plumage and by whole specimens. Louse survivorship was compared between these treatments and two controls. Second, we compared louse abundance on crested auklets versus a closely related congener that nests in close association. Louse survivorship did not differ between crested auklet treatments and controls. Comparison of ectoparasite loads showed that crested auklets had significantly higher louse abundance than least auklets (A. pusilla), even after controlling for body size. Our results failed to support two expectations for chemical defense. Presence of the crested auklet plumage odorant in our experiments did not reduce louse life span. Presence of the aldehyde odorant in nature did not reduce louse abundance on crested auklets. Hence we conclude that the aldehyde odorant is not immediately lethal to lice at natural concentrations in plumage.     

Performance, chewing activity, and ruminal parameters in yearling beef steers fed early-harvested sorghum silage: Effect of chop length and wheat straw addition

Two experiments were conducted to evaluate effects of silage chop length (SCL) and long wheat straw (WS) addition on performance, ruminal parameters, and chewing activity of yearling beef steers. The aim of the first experiment was to measure dry matter (DM) intake, average daily gain (ADG) and feed conversion (FC). For this, 59 Angus yearling steers were assigned to one of the four treatments in a 2 × 2 factorial arrangement. The factors were SCL (i.e., 5.8 and 9.4 mm mean particle length, MPL) and WS addition (i.e., 0 and 100 g/kg). Diets consisted of 792 g/kg of early-harvested sorghum silage (SS, Sorghum bicolor (L.) Moench.), 200 g/kg of pelleted sunflower meal, and 8 g/kg of urea and mineral–vitamin supplements. The amount of SS was reduced by 100 g/kg when WS was added to the diet. The second experiment, which aimed to evaluate ruminal parameters and chewing activity, consisted of two treatments with four rumen-cannulated steers fed with a diet comprised of finely chopped SS (5.8 mm MPL) either with or without WS. In the first experiment, SCL had no effect on DM intake, ADG or FC, while addition of WS depressed DM intake and ADG and had a negative effect on FC, without interactions between the factors. In the second experiment, WS addition reduced DM intake and volatile fatty acid concentration, but did not affect rumen pH or chewing activity. Results suggest that WS addition to these SS-based diets containing a high aNDF did not improve the ruminal environment, did not affect chewing activity and had a negative effect on steer performance, while SCL may not affect performance of beef steers.     

Lineage sorting in multihost parasites: Eidmanniella albescens and Fregatiella aurifasciata on seabirds from the Galapagos Islands

Parasites comprise a significant percentage of the biodiversity of the planet and are useful systems to test evolutionary and ecological hypotheses. In this study, we analyze the effect of host species identity and the immediate local species assemblage within mixed species colonies of nesting seabirds on patterns of genetic clustering within two species of multihost ectoparasitic lice. We use three genetic markers (one mitochondrial, COI, and two nuclear, EF1‐α and wingless) and maximum likelihood phylogenetic trees to test whether (1) parasites show lineage sorting based on their host species; and (2) switching of lineages to the alternate host species depends on the immediate local species assemblage of individual hosts within a colony. Specifically, we examine the genetic structure of two louse species: Eidmanniella albescens, infecting both Nazca (Sula granti) and blue‐footed boobies (Sula nebouxii), and Fregatiella aurifasciata, infecting both great (Fregata minor) and magnificent frigatebirds (Fregata magnificens). We found that host species identity was the only factor explaining the patterns of genetic structure in both parasites. In both cases, there is evident genetic differentiation depending on the host species. Thus, a revision of the taxonomy of these louse species is needed. One possible explanation of this pattern is extremely low louse migration rates between host species, perhaps influenced by fine‐scale spatial separation of host species within mixed colonies, and low parasite infrapopulation numbers.     

高嵌体与纤维桩核冠修复对后牙牙体缺损疗效观察及对患者咀嚼能力和牙龈状况的影响

摘要 目的：观察高嵌体修复与纤维桩核冠修复对后牙牙体缺损疗效及对患者咀嚼能力和牙龈状况的影响。方法：选取2020年11月～2021年11月收治的60例牙体缺损患者作为研究对象,根据患者治疗意愿分为对照组和研究组,其中对照组26例、观察组34例。对照组行纤维桩核冠修复治疗,观察组行高嵌体修复治疗,对比两组患者修复效果、咀嚼功能、牙龈指数（GI）和菌斑指数（PLI）评分、并发症发生情况、满意度。结果：经统计发现,观察组邻面接触、表面质地、边缘密合度、舒适度等均优于对照组,两组比较具有明显差异（P<0.05）;修复前,两组患者咀嚼功能评分比较无差异（P>0.05）,修复后,观察组较对照组高（P<0.05）;修复前,两组GI和PLI评分比较无差异（P>0.05）,修复后,两组评分均有所降低,且观察组低于对照组（P<0.05）;观察组并发症发生率为2.94 %,对照组并发症发生率为11.54 %,观察组与对照组比较无差异（P>0.05）;观察组患者满意度为94.12 %,对照组患者满意度为73.08 %,观察组明显高于对照组（P<0.05）。结论：高嵌体修复与纤维桩核冠修复用于治疗牙体缺损,高嵌体修复的临床疗效更佳,患者咀嚼能力和牙龈健康程度明显提升,GI和PLI评分明显降低,有效减少并发症,提高满意度。值得临床推广使用。     

Effect of roughage level in a total mixed ration on feed intake, ruminal fermentation patterns and chewing activity of early-weaned calves with ad libitum access to grass hay

In this study, two total mixed rations (TMR, based on dry ingredients) consisting (per kg dry matter (DM)) of 300 or 400 g finely chopped hay mixture of grass and alfalfa (H30 versus H40) were compared concerning their effects on dry matter intake (DMI), ruminal fermentation patterns and chewing activity of early-weaned (8 weeks milk-fed) calves. Ten ruminally cannulated male German Holstein calves were randomly assigned to two dietary treatments (n = 5) and observed from an age of 8–15 weeks. One group received the H30 (11.3 MJ metabolizable energy (ME)/kg DM) and the other the H40 (10.7 MJ ME/kg DM) TMR. All calves received grass hay (9.0 MJ ME/kg DM) separately. Water, TMR and hay were offered ad libitum twice daily (08:00 and 16:00 h). Rumen fluid was collected via cannula at an age of 9, 11, 13 and 15 weeks, twice weekly just prior to as well as 1, 3, 5 and 7 h after morning feeding. Chewing activity was recorded by a special head collar. As the calves aged DMI increased rapidly congruent with the recommended range for weaned calves. Because of the differing energy supply, calves receiving the H30 TMR were heavier than calves receiving the H40 TMR (139 kg versus 123 kg, P=0.007). During the trial ruminal pH of all calves were within the target range (6.2 ± 0.5), indicating physiological ruminal fermentation patterns. Daily mean ruminal pH was uninfluenced by treatment, however at an age of 13 and 15 weeks H30 showed a higher short chain fatty acid (SCFA) level than H40 (P=0.098; P=0.036). At an age of 15 weeks H30 showed a critical decrease in ruminal pH (3 h after feeding: 5.7) corresponding to a higher ruminal SCFA concentration (148.2 mmol/L, P=0.007). Chewing activity was well developed at an early age due to an increasing DMI after weaning. At an age of 15 weeks chewing activity (per day: 613–743 min total chewing; 358–418 min rumination) was similar to that of adult cows. In summary, feeding a dry TMR consisting per kg DM of 300–400 g hay to early-weaned calves can be recommended for a successful calf rearing up to an age of 15 weeks.     

Effects of inclusion of neutral detergent soluble fibre sources in diets varying in forage particle size on feed intake, digestive processes, and performance of mid-lactation Holstein cows

The aim of this study was to evaluate effects of partial replacement of neutral detergent soluble fibre (NDSF) for starch in diets varying in particle size (PS) of alfalfa hay on chewing activities, ruminal fermentation, nutrient digestibility and performance in mid-lactation dairy cows. Eight multiparous Holstein cows (146 ± 6.0 d in milk; 36.7 ± 2.57 kg milk/d) were used in a replicated 4 × 4 Latin square design with four 21 d periods with the last 7 d for data collection. The experiment was a 2 × 2 factorial arrangement with 2 levels of NDSF (low = 85 g/kg or high = 130 g/kg diet dry matter) each combined with 2 PS (short = 20 mm or long = 40 mm) of alfalfa hay. Results show that forage PS alone, or in combination with NDSF inclusion, had no effect on dry matter (DM) intake. Although total chewing, eating and ruminating times were not affected by treatments, eating time per kg of neutral detergent fibre (NDF) ingested was higher in long versus short alfalfa hay-based diets (P<0.05). Feeding long forage PS increased sorting of the diet against particles >19 mm, and in favor of those <8 mm (P<0.05). Feeding diets high in NDSF lowered DM intake (P<0.05), but increased apparent digestibility of all nutrients including NDF (P<0.05) independent of forage PS. Ruminal pH and concentrations of total volatile fatty acids were unaffected by dietary treatments, however the proportion of butyrate was higher in ruminal fluid of cows fed high NDSF diets (P<0.05). Changes in milk composition included lower milk crude protein content in high NDSF diets and higher lactose content for short hay-based diets (P<0.05). That milk yield and milk energy output were similar in low versus high NDSF diets suggests that high NDSF-fed cows had higher energy efficiency due to lower DM intake. Results suggest that, independent of forage PS, NDSF sources can be successfully included to partly replace starchy grains in diets exceeding minimum fibre recommendations.     

Miswak and oral health: An evidence-based review

Poor oral health has been associated with several chronic and systemic disease. Currently, the most common method of teeth cleaning is the use of a toothbrush together with dentifrices. However, natural chewing stick such as S. persica miswak is still used in many developing countries due to their low cost and availability. The present review aims to summarize the evidences on effectiveness of miswak in promoting oral health. The search was performed using Medline via Ebscohost, Scopus and Google Scholar database to obtain relevant articles published between 2010 to May 2020 using the following set of keywords 1) Miswak OR Salvadora OR persica AND 2) dental OR caries OR plaque OR oral OR orthodontics. Isolated microbial inhibition studies were excluded from the review due to its well-established wealth of literature. Miswak was administered as ten different forms, namely mouthwash, toothpaste, chewing stick, essential oil, aqueous extract, ethanol extract, probiotic spray, dental varnish, dental cement or chewing gum. All studies reported a positive effect of miswak as an anti-plaque, anti-gingivitis, anti-cariogenic, promotion of gingival wound healing, whitening properties, orthodontic chain preservation, and biocompatibility with oral cells. Miswak in its different forms demonstrated positive effect towards oral health maintenance and management.     

Energieumsatz wachsender Broiler in Abhängigkeit von der Umgebungstemperatur

In einem nach dem lateinischen Quadrat (3 × 3) durchgeführten Versuch an 3 pansenfistulierten laktierenden Milchkühen (LM 550 bis 580 kg) wurden Effekte von drei Partikellängen faserreichen Heus (28,7 mm; 9,2 mm und 2,9 mm) mit ca. 60% NDF in der DM geprüft. In einem weiteren dreifaktoriellen Versuch an 8 Hammeln (4 Tiere mit Pansenfisteln, mittlere Lebendmasse 68 kg) wurden die Haupt‐ und Wechselwirkungen der oben genannten Partikellängen bei zwei unterschiedlichen Kraftfutterstufen (10,4 bis 13,3 und 29,5 bis 40,1% in der Ration) und zwei Fütterungsniveaus (restriktiv und ad libitum) untersucht. Die Zerkleinerung faserreichen Heus auf 9,2 mm hatte keinen negativen Einfluß auf die Kauaktivität, während eine weitere Abnahme der mittleren Partikellänge auf 2,9 mm zu einer deutlichen Reduzierung sowohl der Wiederkaudauer (um 52% bei Schafen und 36% bei Milchkühen) als auch des Kau‐ und Wiederkauaufwandes (Zeit je Einheit DM oder NDF) führte. Diese negative Wirkung verstärkte sich mit der Erhöhung des Kraftfutteranteils in der Ration. Bei Schafen ergab sich bei ad libitum Fütterung eine höhere Heuaufnahme weniger durch Verlängerung der Wiederkaudauer sondern eher durch Reduzierung des Kauaufwandes. Anhand der pH‐Werte, der Bicarbonatkonzentration und des C2 : C3‐Verhältnisses kann bei Partikellängen von 28,7 und 9,2 mm von günstigen Fermentationsbedingungen ausgegangen werden, während bei gemahlenem Heu (2, 9 mm) anhand dieser Parameter auf eine gewisse Beeinträchtigung der Pansenfermentation geschlossen werden kann.