Effect of in ovo glyphosate injection on embryonic development,serum biochemistry,antioxidant status and histopathological changes in newly hatched chicks

This study aimed to investigate the potential toxic effects of pure glyphosate or Roundup^® on hatchability, serum biochemistry and histopathological observation of the liver and kidney of newly hatched chicks. On day six, a total of 225 fertile eggs were obtained from Huafeng breeder hens. The eggs were randomly divided into three treatments: (a) the control group injected with deionized water, (b) the glyphosate group injected 10 mg pure glyphosate/Kg egg mass and (c) the Roundup group injected 10 mg the active ingredient glyphosate in Roundup^®/Kg egg. The results showed a decrease of hatchability rate in chicks treated with Roundup^® (66%). In addition, no significant change was observed in body weights, yolk sac weight and relative weight organs except the liver and kidney were significantly increased with groups treated with glyphosate and Roundup^® compared to the control group. The results showed that serum protein profiles were linearly significantly increased of serum phosphor, uric acid, aspirate aminotransferase, alanine transaminase and alkaline phosphatase in groups treated with Roundup^®, as well as the serum concentrations of triglyceride altered after treatment with glyphosate. Furthermore, oxidative stress was observed in the treated chicks, the glyphosate and Roundup^® induced changes of the content of malondialdehyde in both the liver and kidney, moreover decrease of glutathione peroxidase, total superoxide dismutase and catalase activity in the kidney tissue and serum. Additionally, changes also happened in the histomorphology of the liver and kidney tissue of the treated chicks. It can be concluded that Roundup^® as a probable decrease of hatchability. Exposure to glyphosate alone or Roundup^® caused liver and kidney histopathological alterations, serum parameters imbalances and oxidative stress, also induced a variety of liver and kidney biochemical alterations that might impair normal organ functioning in newly hatched chicks.     

In ovo injection of branched‐chain amino acids: Embryonic development,hatchability and hatching quality of turkey poults

In this study, the influence of a branched‐chain amino acid blend (BCAA composed of 3 l ‐leucine:1 l ‐valine:2 l ‐isoleucine) injected into the amniotic fluid was evaluated for embryonic growth, yolk‐sac (YS) utilization and development of gastrointestinal tract (GIT) and skeletal muscles of turkey embryos from day 24 of incubation (24E) to hatching, together with hatchability, poult quality and liver L* (lightness), a* (redness) and b* (yellowness) values at hatch. At day 22 of incubation, embryonated eggs (n = 240) were assigned to three treatments, that is, eggs were not injected (control, NC) or injected with 1.5 ml sterile solution with 0.9% salt (SA) or 0.2% BCAA blend (BCAAb). These solutions were injected manually into the amniotic fluid of the embryonated eggs. To determine weights and lengths (where appropriate) of the studied organs and tissues, four embryonated eggs and poults per treatment were selected at 24E and at hatch. While the BCAAb decreased the YS and embryo weight, hatchability and the liver L* value, it increased the weight and quality of poults and the weights of breast and thigh muscles at hatch. In conclusion, the in ovo feeding of the BCAA blend negatively affected hatchability but positively affected hatching weight and poult quality by improving development of skeletal muscles and by regulating energy metabolism.     

Effects of in ovo injection of chrysin,quercetin and ascorbic acid on hatchability,somatic attributes,hepatic oxidative status and early post‐hatch performance of broiler chicks

An experiment was conducted to evaluate the effects of in ovo injection of chrysin, quercetin and ascorbic acid on hatchability, somatic attributes, hepatic antioxidant status and early post‐hatch growth performance of broiler chicks. Four hundred and eighty embryonated broiler breeder eggs containing live 18‐day‐old embryos were divided into six groups of 80 eggs each. One group remained intact and served as a control group (i), whereas the other five groups were injected with the prepared injection solutions as follows: (ii) 0.05 ml distilled water; (iii) 0.05 ml distilled water containing 6 mg ascorbic acid; (iv) 0.05 ml dimethyl sulfoxide (DMSO); (v) 0.05 ml DMSO containing 4.5 mg quercetin; and (vi) 0.05 ml DMSO containing 4.5 mg chrysin. The hatchability rate, hatching weight, residual yolk sac weight, yolk sac‐free body weight, liver weight, hepatic glutathione peroxidase and total superoxide dismutase activities, as well as malondialdehyde concentrations, were not affected by the injected solutions. There were no differences between chicks hatched from the control and in ovo injected eggs in weight gain, feed intake and feed conversion ratio from 0 to 11 days of age. However, the specific contrast performed between the in ovo injected groups and intact eggs revealed that in ovo injection significantly increased hatchability rate (p = .0493). This finding also implies that our injection procedure was harmless. In conclusion, the intra‐egg injection of chrysin, quercetin or ascorbic acid at the injection rates used in this study did not have a significant effect on hatchability, somatic characteristics, early growth performance and hepatic antioxidant status of broiler chicks. However, the overall hatchability was higher in the in ovo injected eggs as compared to non‐injected ones. These findings also confirmed the harmlessness of the procedure developed for in ovo injection in this study.     

The impact of in ovo injection of l-arginine on hatchability,immune system and caecum microflora of broiler chickens

The present article was conducted to evaluate the effect of in ovo injection of arginine on hatchability, immune system and caecum microflora of broiler chickens. For this reason, 300 fertile eggs were used in a completely randomized design with three experimental treatments. The experimental groups included: 1%–0.5% l -arginine (100 eggs), 2%–1% l -arginine (100 eggs), 3- control [included both sham control (injection of distilled water; 50 eggs) and control (no injection; 50 eggs)], which were injected on d 14 of incubation. After hatching, chicks of each experimental group (0.5% l -arginine, 1% l -arginine, and control groups) were randomly divided into four equal groups (as replicates) and reared for 30 days. Weight and feeding of chickens were recorded. Next, blood samples of chickens were collected on day 30 to evaluate antibody titre. Also, chickens were slaughtered on 24 and 30 days of the experiment to evaluate immune system organs and caecum microflora. Based on the results, in ovo injection of l -arginine had no significant effect on hatchability, body weight, antibody titre, spleen, bursa of Fabricius and thymus weight (p > .05). On the other hand, treatments significantly affected feed intake and feed conversion ratio (p < .05). As a novel finding, in ovo injection of l -arginine increased caecal Lactobacillus (p < .01), while decreasing Coliform and Escherichia Coli bacteria (p < .01). However, treatments did not influence caecal Enterococcus (p > .05). The overall results indicated that in ovo injection of 0.5% l -arginine had a better improving effect on caecal microflora and then considered as a recommended level of the present experiment.     

鸡胚注射碳酸化合物及提高孵化温度对种蛋孵化率、雏鸡糖原状态的影响

选择800枚16~21d肉用种蛋开展两个试验,评估胚胎注射碳水化合物对高温(37.5和38.5℃)孵化后胚胎的孵化特性、出壳小鸡的重量和相对重量以及孵化时间、肝脏和胸肌糖原含量、糖原指数的影响。试验对照组分为正对照组(不注射)、负对照组(注射生理盐水),处理组分别对鸡胚注射50、100、150、200和250mg碳水化合物。结果显示:胚胎注射200和250mg碳水化合物较50mg碳水化合物组显著降低了胚胎的孵化时间(P<0.05)。胚胎注射50、100、150、200和250mg碳水化合物较正对照组显著提高了出壳鸡只重量及相对重量(P<0.05),各处理组较对照组显著提高了出壳鸡只相对重量(P<0.05)。正对照组和碳水化合物处理组较负对照组显著降低了肝脏相对重量(P<0.05)。胚胎注射250mg碳水化合物组肝糖原含量最高(P<0.05),而正对照、负对照和50mg碳水化合物组肝糖原含量最低(P<0.05)。胚胎注射100、150、200和250mg碳水化合物较50mg碳水化合物和对照组显著提高了胸肌相对重量(P<0.05),胚胎注射150、200和250mg碳水化合物较对照组、50和100mg碳水化合物组显著提高了出壳鸡只的糖原指数(P<0.05)。综上所述,在该研究条件下提高鸡胚孵化后期(16~21d)的孵化温度和蛋鸡日龄会对出壳小鸡的体重和糖原状态产生负面影响,但鸡胚注射100mg碳水化合物会缓解鸡胚高温孵化对仔鸡生长的抑制,使糖原状态得以恢复。     

Effect of adjuvants on in ovo vaccination against Newcastle disease on hatchability,performance and antibody titres in commercial pullets

This study was conducted to investigate the efficacy of in ovo administration of aluminium hydroxide (AH) and/or mannan oligosaccharide (MOS) adjuvants along with lentogenic VG/GA strain‐Avinew to alleviate the embryonic pathogenicity of Newcastle disease virus. Six hundred and thirty fertilized Bovans eggs were divided into nine groups of 70 each incubated in a commercial hatchery and administered with eight types of in ovo injections in a factorial design of 2 × 2 × 2 including with/without AH, MOS and Newcastle disease vaccine (NDV), and one uninjected group on day 18 of incubation. Hatchability was higher in the eggs received MOS and/or AH adjuvants plus NDV compared those injected with NDV alone which confirmed the attenuation of NDV. However, the average daily feed intake and feed conversion ratio of pullets hatched from NDV‐injected eggs were significantly reduced, but did not affect growth performance during 0‐42 days of age. The performance of pullets hatched from eggs injected with AH, MOS or their mixture with NDV was not significantly different during all growth periods. Pullets from MOS + vaccine injected eggs had significantly higher antibody titres against NDV compared to those hatched from either injected with saline or uninjected on d 28 (p < .05). In addition, AH plus vaccine and MOS significantly improved total anti‐SRBC and IgG respectively. Histological observation revealed that injection of MOS adjuvant into eggs led to increase crypt depth, whereas AH injection caused a reduction in villus surface area of jejunum in chicks on d 14 post‐hatch. It is concluded that in ovo MOS injection as compared to AH may be more effective to attenuate the embryonic pathogenicity of in ovo NDV injection.     

In ovo feeding of creatine pyruvate modulates growth performance,energy reserves and mRNA expression levels of gluconeogenesis and glycogenesis enzymes in liver of embryos and neonatal broilers

The effects of in ovo feeding (IOF) of creatine pyruvate (CrPyr) on the growth performance, energy reserves and mRNA expression levels of gluconeogenesis and glycogenesis enzymes in liver of late‐term embryos and neonatal broilers were investigated. After candling on 16 day of incubation, a total of 960 eggs were randomly assigned to three treatments: (i) non‐injected control, (ii) saline group injected with 0.6 ml of 0.75% physiological saline and (iii) Creatine pyruvate group injected with 0.6 ml of physiological saline containing 12 mg CrPyr/egg. After hatching, 120 male chicks with average body weight (BW) were randomly allocated into each treatment group for a 7‐day feeding trial. The results showed that broilers subjected to CrPyr treatment had higher BW than those of the control and saline groups on 1, 3 and 7 day post‐hatch, as well as the yolk sac weight on 19 day of incubation (19 E), the day of hatch and 3 day post‐hatch (p < .05). Compared with the control and saline groups, IOF of CrPyr increased the plasma creatine concentration on the day of hatch, and the plasma pyruvate concentration on the day of hatch and 3 day post‐hatch (p < .05). Moreover, IOF of CrPyr increased the liver pyruvate and glucose concentrations on 19 E and the day of hatch, and the liver glycogen concentration during the experiment (p < .05). Broilers in the CrPyr group showed increased mRNA expression levels of pyruvate carboxylase (PC), phosphoenolpyruvate carboxykinase (PEPCK) and glycogen synthase 2 (GYS2) on 19 E and the day of hatch (p < .05). These results indicated that IOF of CrPyr increased energy reserves in liver of embryos and neonatal broilers possibly through upregulating the mRNA expression levels of PC, PEPCK and GYS2, which could benefit the increase of BW in broilers on 7 day post‐hatch.     

In ovo injection of ascorbic acid and higher incubation temperature modulate blood parameters in response to heat exposure in broilers

1. This study analysed whether in ovo injection of ascorbic acid before incubation and at high incubation temperature influenced blood characteristics and performance in broilers reared in different temperature conditions.

2. A total of 3,000 fertile eggs from broiler breeders (Cobb®) were randomly divided into three incubation treatments: no ascorbic acid injection and egg incubation at 37.5°C (control); no ascorbic acid injection and egg incubation at 39°C; in ovo ascorbic acid injection prior to incubation (6 µg AA/100 µl water) and egg incubation at 39°C.

3. Male chicks hatched from the three incubation treatments were submitted to three distinct rearing temperatures (control, cold and hot) from the third week of age onwards (540 chicks were divided into 6 treatments with 5 replicates per treatment).

4. Measurements at 42 d showed that, after egg incubation at 39°C, the haematocrit, haemoglobin values, ionised calcium and glucose concentrations were increased and base excess values were reduced. However, in ovo injection of ascorbic acid normalised all these parameters.

5. Partial CO₂ and O₂ pressure were higher with increased rearing temperature. Blood pH was lower when eggs were incubated at 39°C and injected with ascorbic acid. In ovo injection of ascorbic acid induced leucocytosis due to lymphocytosis and heterophilia, restored basophils rate and led to monocytopoenia. Leucocytosis was triggered by hot rearing temperature due to lymphocytosis, eosinophilia and heterophilia.

6. The results obtained in this study showed that in ovo injection of ascorbic acid before incubation may serve as a long-term stimulator and modulator of the broiler immune system, and that high incubation temperatures induce adaptations in the electrolytic balance, minimising or avoiding the occurrence of respiratory alkalosis under hot rearing temperature.     

Effects of lycopene supplementation in both maternal and offspring diets on growth performance,antioxidant capacity and biochemical parameters in chicks

This study investigated the effects of different supplementation ways of lycopene during pre‐hatch (from the diet of hens) and post‐hatch (from the diet of progeny) on production performance, antioxidant capacity and biochemical parameters in chicks. In total, 360 hens were fed diets supplemented with 0 (control group) or 40 mg lycopene/kg diet. From 28 to 34 days after the start of supplementation (30 weeks old), 650 qualified eggs were collected to artificial incubation. In this trial, 2 × 2 factorial designs were used. Male chicks hatched from hens fed with 0 or 40 mg lycopene/kg diet were fed a diet containing either 0 or 40 mg lycopene/kg diet. The results showed that, relative to control, in ovo‐deposited lycopene significantly increased chick birth body weight, improved liver total antioxidant capacity (T‐AOC), glutathione peroxidase (GSH‐Px) and glutathione to oxidized glutathione ratio (GSH: GSSG), and significantly declined liver malondialdehyde (MDA) level and increased liver lycopene content during 0–14 days after hatching. On days 14 after hatching, dietary lycopene in diet began to take over gradually. Both supplementation ways of lycopene increased immune organ index, serum high‐density lipoprotein (HDL) cholesterol, villus length and villus/crypt in duodenum, jejunum and ileum. Data in this study suggested lycopene supplementation could improve antioxidant capacity and immune function, and regulate lipid metabolism in chicks.     

Effects of 25‐hydroxycholecalciferol supplementation in maternal diets on milk quality and serum bone status markers of sows and bone quality of piglets

Twenty primiparous sows were allocated to two treatments to evaluate the effects of maternal 25‐hydroxycholecalciferol (25OHD₃) supplementation during gestation and lactation on milk quality and serum bone status markers of sows and bone quality of piglets. Immediately after mating, sows were randomly allotted to one of two diets supplemented with 50 µg/kg 25OHD₃ or basal diets without 25OHD₃. Blood and milk samples were obtained. At birth and weaning, 10 piglets from each treatment were killed for bone quality analysis. 25OHD₃‐fed sows provided one more piglet at farrowing and 1.17 more piglets at weaning than sows fed basal diets. The contents of solids not‐fat, protein, fat or lactose were increased in milk from days 7 and 14 of lactation in 25OHD₃‐supplemented sows and 25OHD₃ concentrations in milk were increased by dietary 25OHD₃ supplementation. Dietary 25OHD₃ supplementation increased serum alkaline phosphatase activity but had no effect on serum tartrate‐resistant acid phosphatase activity of sows. Maternal 25OHD₃ supplementation improved bone strength, density and ash content of newborn piglets rather than those of weaning piglets. In conclusion, 25OHD₃ supplementation in maternal diets improved reproductive performance, milk quality and bone status of sows as well as bone quality of newborn piglets.     

不同属种肉类对大鼠血清生化指标与抗氧化能力的影响

探讨了不同属种肉类对大鼠血清生化指标和抗氧化机能的影响。试验选取体重约177 g的雄性SD大鼠90只,随机分为3组即狗肉组、羊肉组、鸭肉组,分别将日粮中的主要蛋白源替换为狗肉、羊肉、鸭肉(CP 31%)。试验期为4周。结果表明:饲喂狗肉和羊肉能显著提高大鼠生长性能,且前者使得大鼠血清碱性磷酸酶(ALP)活性极显著升高(P<0.01);而饲喂鸭肉使得大鼠血清丙氨酸转移酶(ALT)活性显著升高(P<0.05),天冬氨酸转移酶(AST)、血清尿素氮(BUN)活性极显著升高(P<0.01)。不同属种的肉之间,鸭肉组肝脏和肾脏中谷胱甘肽过氧化物酶(GSH-Px)活性均极显著升高(P<0.01)。结果提示:饲喂狗肉和羊肉能促进机体蛋白质合成,有利于蛋白质沉积;饲喂鸭肉则具有增强机体抗氧化的能力。     

Effects of in ovo feeding of L‐arginine on the development of digestive organs,intestinal function and post‐hatch performance of broiler embryos and hatchlings

This study was to investigate the effects of in ovo feeding (IOF) L‐arginine (Arg) solution on the development of digestive organs, the duodenal mucosa of broiler embryos and hatchlings, and the growth performance of chicks during the first week post‐hatch. A total of 720 fertilized eggs with similar weight were randomly allocated to three groups, consisting of eight replicates of 30 eggs each. Three treatments were arranged as non‐injected control, diluent‐injected (0.75% NaCl solution) group and Arg solution‐injected group containing 1% Arg, dissolved in diluent. At 17.5 days of incubation, 0.6 ml of IOF solution was injected into amniotic fluid of each egg of injected groups. Results showed IOF of Arg solution increased (p < .05) the chick embryo weight at 19 days of incubation; the body weight gain of post‐hatch broilers during 1–7 days; the weights of liver, pancreas, proventriculus and gizzard; the concentrations of duodenal ghrelin, vasoactive intestinal peptide and glucagon‐like peptide 2; and the duodenum mucosal enzyme activities of alkaline phosphatase, maltase, sucrase and inducible nitric oxide synthase of 7‐day‐old post‐hatch broilers compared with other groups. The IOF of Arg solution also increased (p < .05) the villus height (VH) and the ratio of VH to crypt depth (CD) and decreased (p < .05) the CD in duodenum of broiler embryos and post‐hatch hatchlings, except for the CD at 19 days of incubation. In conclusion, IOF of 1% Arg solution into the amnion at 17.5 days of incubation could improve the development of digestive organs, the duodenal morphology, the releasing of gastrointestinal hormones and mucosal enzyme activities of broiler embryos and hatchlings and finally the growth performance of chicks during the first week post‐hatch. Therefore, IOF of appropriate Arg solution could be an effective technology for regulating early nutrition supply and subsequent growth development in poultry industry.     

胚蛋注射L-精氨酸对蛋雏鸡孵化性能、1~14日龄肠道发育及血清生化指标的影响

本试验旨在研究胚蛋注射L-精氨酸(L-Arg)对蛋雏鸡孵化性能、1~14日龄肠道发育和血清生化指标的影响。选取47周龄京红1号蛋鸡种蛋1080枚,随机分为3组,分别为未注射对照(NC)组、生理盐水注射对照(SC)组和L-Arg注射(Arg)组,每组8个重复,每个重复45枚种蛋。在孵化第17.5天时,Arg组每枚蛋注射0.1 mL 10%的L-Arg溶液(0.85%生理盐水作溶剂,10 mg L-Arg/枚蛋),SC组注射相同剂量的0.85%生理盐水。出壳后,每组选取体重相近的健康母雏120只,随机分为8个重复。试验期14 d。结果表明:1)与NC和SC组相比,胚蛋注射L-Arg对1日龄蛋雏鸡的孵化率和出孵重无显著影响(P>0.05),但显著降低卵黄囊重(P<0.05)。2)与NC和SC组相比,胚蛋注射L-Arg显著提高1日龄蛋雏鸡的空肠长度、3日龄时的十二指肠长度和14日龄时的空肠和回肠长度(P<0.05),对3日龄蛋雏鸡空肠内容物脂肪酶活性有增加趋势(P=0.084)。3)与NC组相比,胚蛋注射L-Arg显著提高14日龄蛋雏鸡的空肠上皮细胞增殖指数(P<0.05)。4)与NC组相比,胚蛋注射L-Arg显著降低3和14日龄蛋雏鸡的血清甘油三酯(TG)含量(P<0.05),显著增加3和14日龄时的血清总胆固醇(TC)和低密度脂蛋白(LDL)含量(P<0.05)。与SC组相比,胚蛋注射L-Arg显著增加14日龄蛋雏鸡的血清高密度脂蛋白(HDL)和葡萄糖(GLU)含量(P<0.05)。由此可见,胚蛋注射10 mg L-Arg对蛋雏鸡的孵化率和出孵重等孵化性能无不良影响;胚蛋注射10 mg L-Arg促进蛋雏鸡的脂质代谢和糖代谢,为早期肠道发育提供更多能量,提高空肠上皮细胞增殖指数,增加肠道长度,促进早期肠道发育。     

Gender,caponization and exogenous estrogen effects on lipids,bone and blood characteristics in Taiwan country chickens

This study investigated gender, caponization and exogenous estrogen effects on lipids, bone and blood characteristics in Taiwan country chickens. Thirty male chickens were caponized at 8 weeks (capons); 15 capons were injected with estrogen (5 mg/bird estradiol 3‐benzoate) every 2 weeks from 8 to 28 weeks, and 15 sham‐operated male (shams) chickens and 15 females were selected for this trial. The results showed that the shams had lower relative abdominal and chest subcutaneous fat than females (P < 0.05). The estrogen‐treated capons had greater relative abdominal and chest subcutaneous fat than shams and capons (P < 0.05), which might result from higher blood very low‐density lipoproteins and triacylglycerol concentrations (P < 0.05). Caponization could dramatically increase relative abdominal fat (506%; P < 0.05). The shams had higher tibia weight and biomechanical properties, such as maximum bone strength and bending moment values than the capons (P < 0.05). Tibia biomechanical properties were reduced by estrogen treatment (P < 0.05). The females obtained the lowest biomechanical value in all treatments (P < 0.05). Histological examination revealed cavity formation in the cortical bone of estrogen‐treated capons and female chickens, which suggested that estrogen reduced bone biomechanical properties by destroying its structural integrity.     

Effects of dietary boron supplementation on some biochemical parameters, peripheral blood lymphocytes, splenic plasma cells and bone characteristics of broiler chicks given diets with adequate or inadequate cholecalciferol (vitamin D3) content

(1) The effects of 5 and 25 mg/kg boron supplementation of diets with inadequate (6.25 microg/kg) or adequate (50 microg/kg) cholecalciferol (vitamin D3) content on some biochemical parameters, tibia characteristics, peripheral blood lymphocyte and splenic plasma cell counts of broilers were investigated. (2) Supplementation of the diet with boron affected plasma concentrations of boron, iron, copper and zinc and also tibia boron, zinc and calcium concentrations but did not have any effect on tibia iron or copper concentrations or tibia ash and tibia weight values. (3) Boron supplementation caused significant increases in splenic plasma cell count but decreased the proximal and distal tibia growth plate widths. There was no effect of boron supplementation on peripheral blood alpha-naphthyl acetate esterase (ANAE) content. Whole blood haematocrit and haemoglobin counts were significantly increased by boron supplementation but there were no effects on leucocyte ratios such as eosinophil, basophil, monocyte, lymphocyte and thrombocyte. (4) In general, the findings of the present study support the hypothesis that boron has an important biological role that affects the mineral metabolism of animals by influencing both biochemical and haematological mechanisms.     

Effects of Chinese herbal mixture on performance,egg quality and blood biochemical parameters of laying hens

The aim of the study was to evaluate the effect of Chinese herbal mixture (CHM) in laying hen diets on performance, egg quality and egg nutrition components, as well as selected blood biochemical parameters. A total of 270 Lohmann Brown laying hens, 24 week of age, were randomly distributed into three dietary treatments and fed for 6 week. The CHM was used at the levels of 0%, 0.5% and 1.0% in the diets of the control and two treatment groups respectively. Each dietary treatment was divided into five replicates, comprising of 18 hens each. Hens were housed in a 3‐tier battery system. Feed and water were provided ad libitum. Blood samples and eggs were collected at the end of the experiment. The results showed that dietary treatments did not affect egg weight, mortality, eggshell thickness, albumen height, Haugh units, eggshell‐breaking strength and egg‐shape index. Dietary supplementation of CHM significantly improved (p < 0.05) laying rate and the lowest feed conversion ratio were observed with 1.0% CHM supplementation diets. CHM supplementation decreased (p < 0.05) cracked‐egg rate, egg yolk cholesterol, blood serum levels of cholesterol, triglyceride, low‐density lipoprotein cholesterol (LDL‐C) and alanine aminotransferase (ALT) and increased blood serum levels of high‐density lipoprotein cholesterol (HDL‐C). No differences in serum total protein, serum albumen, serum glucose and aspartate amino transferase (AST) were observed in hens fed CHM. In conclusion, dietary supplementation with CHM improved egg production and egg quality and reduced serum cholesterol concentrations in laying hens. Dietary supplementation of 1.0% CHM in layer diets may be a feasible means of producing eggs with lower cholesterol and higher egg yolk phospholipid contents for health conscious consumers.     

The effects of early‐age thermal manipulation and daily short‐term fasting on performance and body temperatures in broiler exposed to heat stress

This study was conducted to investigate the effects of thermal manipulation at 5 days of age and short‐term fasting during the warmest part of the day on responses to prolonged heat stress of broilers. A total of 240‐day‐old Ross 308 female broiler chicks were divided into three groups: control, thermal manipulation (chicks were exposed to 36 °C for 24 h at 5 days of age) and short‐term fasting during the warmest part of the day (10.00–17.00 h). Prolonged heat stress was induced daily from 28 to 42 days by heating until the ambient temperature reached 32–35 °C between 10.00 and 17.00 h. Both thermal manipulation and short‐term fasting resulted in a decrease in rectal temperatures and haematocrit values at 35 and 41 days of age. Thermal manipulation improved body weight, feed consumption and feed conversion. However, short‐term fasting caused a reduction in body weight and a deterioration in feed conversion. Short‐term fasting lowered the percentages of carcass, whereas thermal manipulation highered breast yield. Both thermal manipulation and short‐term fasting decreased heart mass and abdominal fat.     

The effect of 25‐hydroxyvitamin D3 and phytase inclusion on pig performance,bone parameters and pork quality in finisher pigs

The objective of this study was to investigate the effects of supplementing both phytase and 25‐hydroxyvitamin D₃ (25‐OH ‐D?) on pig performance, nutrient digestibility, carcass characteristics, bone parameters and pork quality in finisher pigs. The experimental design was a 2 × 2 factorial comprising of four dietary treatments. One hundred and twenty pigs (60 male, 60 female) were blocked according to live weight and sex and allocated to the following dietary treatments: low P (4.81 g/kg) diet (basal) (T1); low P diet + phytase (T2); low P diet + 25‐OH ‐D? (T3) and low P diet + phytase + 25‐OH ‐D? (T4). Pigs supplemented with phytase had a lower average daily feed intake (ADFI ) (2.45 kg vs. 2.59 kg; p  < 0.05) and lower feed conversion ratio (FCR ) (2.74 kg/kg vs. 2.85 kg/kg; p  <  0.05) compared to pigs offered the nonphytase diets. Pigs offered phytase diets had a higher (p  <  0.05) coefficient of apparent total tract digestibility (CATTD ) of ash, phosphorous (P) and calcium (Ca) compared with pigs offered the nonphytase supplemented diets. Pigs offered the 25‐OH ‐D₃ diets had a higher CATTD of N and ash. Pigs offered the phytase diets had increased (p  <  0.05) bone DM , ash, Ca, P and density compared to the nonphytase diets. There was a significant interaction (p  <  0.05) between phytase and 25‐OH ‐D₃ on cook loss. Pigs offered 25‐OH ‐D₃ had increased cook loss over the basal diet; however, there was no effect on cook loss when phytase and 25‐OH ‐D₃ were offered in combination compared to the phytase only diet. Pigs offered 25‐OH ‐D₃ exhibited higher (p  <  0.05) Warner Bratzler shear force values and lower (p  <  0.05) pork lightness (L *) surface colorimeter values. In conclusion, there was no benefit to offering a combination of phytase and 25‐OH ‐D₃ on pig performance, bone parameters or pork quality.