摘要：
The aim of this study was to study the effects of different levels of guar meal (GM) on growth performance of meat ducks, to explore the possibility of GM as an alternative protein resource in meat duck diets. Firstly, the chemical composition, dry matter (DM) digestibility, metabolic energy (ME) were determined. Secondly, a total of four hundred eighty 15-day-old Shuanggui-tou meat ducks were divided into 4 treatments, 1) Control group (0% GM in the diet), 2) 3% GM group (3% GM in the diet), 3) 6% GM group (6% GM in the diet), and 4) 9% GM group (9% GM in the diet). All groups had 8 replicates and 15 birds were included in each replicate. The experiment lasted for 28 days. The average daily gain (ADG), average daily feed intake (ADFI) and feed conversion ratio (FCR) were measured. Results showed that: (1) the DM, CP, EE, CF, Ash, Ca, Pi, GE content of GM is 89.96%, 47.80%, 4.92%, 6.43%, 4.49%, 0.3%, 0.63%, 4.66 Mcal/Kg, respectively, the composition of Met, Lys, Ile, Asp, Glu, Gly, His, Arg, Thr, Ala, Pro, Tyr, Val, Phe in GM is 0.499%, 2.023%, 1.485%, 2.795%, 4.834%, 11.543%, 2.626%, 1.315%, 6.128%, 1.491%, 1.905%, 1.750%, 1.498%, 1.680%, 2.184%, respectively. (2) The DMD and TDDM of GM is 47.13% and 58.31%, respectively. The AME, TME of GM is 2.71 Mcal/Kg and 3.03 Mcal/Kg, respectively. (3) Add GM to the duck diets significant affect the final weight (P<0.05), ADG (P<0.05), FCR (P<0.01), but had no effect on ADFI of ducks (P>0.05). Our results suggest that the GM would be a high quality protein resource in diets for meat ducks. Copyright 2020 Zoological Society of Pakistan
关键词：
Roman laying hens;egg yolk selenium;laying rate;selenium yeast;sodium selenite
摘要：
<jats:p>The objective of this study was to compare the effect of sodium selenite (SS) and selenium yeast (SY) on performance, egg quality, and selenium concentration in eggs and serum biochemical indices in laying hens. Seven hundred twenty healthy Roman laying hens (21 weeks old, 18 weeks in lay) with a similar laying rate (90.27% ± 1.05%) were randomly divided into 5 groups with 6 replicates of 24 hens each. Five diets were prepared as a 1+2×2 factorial arrangement with control and two sources of Se at two levels. Control diet (control) was prepared without adding exogenous selenium (analyzed basal Se content of 0.178 mg/kg). The other four diets were prepared with the control diet supplemented with SY or SS at 0.3 mg/kg (low; L) or 0.5 mg/kg (high; H) to give 5 diets designated as control, SY-L, SY-H, SS-L, and SS-H. The analyzed selenium content in the SY-L, SY-H, SS-L, and SS-H diets were 0.362, 0.572, 0.323, and 0.533 mg/kg respectively. The pre-trial period lasted 7 d, and the experimental period lasted 56 d (30 weeks old), during which the egg production, egg quality, and hen serum parameters were measured. Results showed that selenium source and level had no effect (P > 0.05) on average daily egg weight and feed conversion ratio (FCR). However, the laying rate was different at the L and H levels of supplementation, regardless of source, such that hens that were supplemented had a higher performance than that of the control, and the H level of supplementation lead to a higher laying rate than that of the L level (P < 0.05). There was a difference in average daily feed intake (ADFI) with an interaction in selenium source and level (P < 0.05), such that SS-L was higher than other selenium supplemented treatment or control. There were no significant differences in egg quality (P > 0.05); at the high level, SY had higher egg yolk selenium compared with SS. However, within SY, adding 0.5 mg/kg selenium led to higher egg yolk selenium than 0.3 mg/kg selenium (P < 0.05). Moreover, adding 0.3 mg/kg SY, 0.3 mg/kg, or 0.5 mg/kg SS to the basal diet had no significant effect on the selenium content in the egg (P > 0.05). There were no significant differences in serum biochemical indices among the five groups (P > 0.05). In conclusion, adding a high level of selenium in the diet of laying hens significantly increased egg production, and addition of a high level of selenium in the form of SY led to a higher deposition of selenium in the yolk than that of SS. These results indicate that adding 0.5 mg/kg of SY in the diet of laying hens would result in Se-enriched eggs.</jats:p>
关键词：
Gut microbiome;Nonspecific immunity;Specific immunity;Inflammation
摘要：
The intestinal tract is a host to 100 trillion of microbes that have co-evolved with mammals over the millennia. These commensal organisms are critical to the host survival. The roles that symbiotic microorganisms play in the digestion, absorption, and metabolism of nutrients have been clearly demonstrated. Additionally, commensals are indispensable in regulating host immunity. This is evidenced by the poorly developed gut immune system of germ-free mice, which can be corrected by transplantation of specific commensal bacteria. Recent advances in our understanding of the mechanism of host -microbial interaction have provided the basis for this interaction. This paper reviews some of these key studies, with a specific focus on the effect of the microbiome on the immune organ development, nonspecific immunity, specific immunity, and inflammation. (C) 2020, Chinese Association of Animal Science and Veterinary Medicine. Production and hosting by Elsevier B.V. on behalf of KeAi Communications Co., Ltd.
摘要：
<jats:title>Abstract</jats:title><jats:p>The objective of this experiment was to evaluate the effects of dietary supplementation with porous zinc oxide (HiZox) on growth performance, intestinal microbiota, morphology, and permeability in weaned piglets. A total of 128 weaned piglets [(Landrace×Yorkshire)×Duroc] with an average body weight (BW) of (6.55±0.25kg; 21d of age) were randomly assigned to four dietary treatments: (1) a corn‐soybean basal diet; (2) basal diet+3,000mg/kg conventional ZnO; (3) basal diet+200mg/kg HiZox; (4) basal diet+500mg/kg HiZox. The experiments lasted for 28days. Incremental HiZox in the diet increased ADG (linear <jats:italic>p</jats:italic>=0.015; quadratic <jats:italic>p</jats:italic>=0.043) and ADFI (linear <jats:italic>p</jats:italic>=0.027; quadratic <jats:italic>p</jats:italic>=0.038), and the diarrhea index decreased linearly and quadratically (<jats:italic>p</jats:italic><0.01) as HiZox supplemented increased. Furthermore, supplementation with HiZox increased the amounts of <jats:italic>Lactobacillus </jats:italic>spp. (<jats:italic>p</jats:italic><0.05) in the ileum and cecum in comparison with that of control treatment or 3,000mg/kg ZnO treatment, while decreased the populations of <jats:italic>Escherichia coli</jats:italic>, <jats:italic>Clostridium coccoides</jats:italic>, and <jats:italic>Clostridium. leptum</jats:italic> sub<jats:italic>group</jats:italic> (<jats:italic>p</jats:italic><0.05) in the ileum and cecum relative to those in control treatment. The addition of HiZox increased the villus height and villus‐to‐crypt ratio (VC) of duodenum, jejunum, and ileum (<jats:italic>p</jats:italic><0.05), while decreased the crypt depth of jejunum (<jats:italic>p</jats:italic><0.05) and tended to reduce the crypt depth of duodenum (<jats:italic>p</jats:italic><0.10) compared with the control treatment. Piglets fed with 500mg/kg HiZox had lower serum D‐lactate and diamine oxidase (DAO) than those fed with basal control diet or 3,000mg/kg ZnO diet (<jats:italic>p</jats:italic><0.01). The results suggested that supplementation with HiZox modulated intestinal microbial composition and improved intestinal morphology, which may exert protective effects on the integrity of the mucosal barrier function of weaned piglets, was as efficacious as pharmaceutical doses of ZnO in enhancing growth performance, indicating that the HiZox may be a promising alternative to pharmaceutical doses of ZnO.</jats:p>
