[Application value of arousal threshold in obstructive sleep apnea].

The pathogenesis of obstructive sleep apnea (OSA) includes anatomical and non-anatomical factors, and the arousal threshold (ArTH) is one of the important non-anatomical factors. At present, the main method is to assess the increased respiratory effort due to arousal to determine the arousal threshold, and invasive epiglottic or esophageal manometry is the gold standard, while the non-invasive continuous positive airway pressure (CPAP) method and polysomnography (PSG) ventilation signal conversion method are also widely used. Arousal threshold is expected to serve as an important evaluation index and potential target for drug therapy in OSA, which is of great importance for realization of precise treatment of OSA. This article focused on the method and clinical significance of OSA arousal threshold.

[Efficacy and safety of endothelin receptor antagonists combined with phosphodiesterase 5 inhibitor in the treatment of pulmonary arterial hypertension: a network meta-analysis].

Objective: To examine the efficacy and safety of endothelin receptor antagonists (ERA) combined with phosphodiesterase 5 inhibitors (PDE5i) in the treatment of pulmonary artery hypertension (PAH). Methods: Computer-based retrieval was performed on PubMed, Cochrane Library, CNKI, Wanfang, and VIP database (up to February 12th, 2021). Randomized controlled trials about endothelin receptor antagonists (ERAs) or PDE5i in patients with PAH were collected. The change of 6-minute walking distance (6MWD) in 12-16 weeks was used as primary outcome index. Case fatality rate, worsening clinical events, WHO functional class (FC) improvement, adverse events (AEs), serious adverse events (SAE) were the key secondary outcomes indicators. STATA 16.0 software was used for network meta-analysis, and the pooled estimates of odds ratios (ORs) or weighted mean differences (WMDs) and 95% confidence intervals (CIs) of the results were shown. To help explain ORs and WMDs, we used the surface under the cumulative ranking curve (SUCRA) to calculate the probability of each intervention. Results: We included 29 trials with 5 949 participants. In network meta-analysis, Bosentan combined with Sildenafil (WMD=53.93, 95%CI=6.19-101.66) had shown the greatest improvement in 6MWD compared with placebo, followed by Bosentan combined with Tadalafil (WMD=50.84, 95%CI=7.05-94.62), Ambrisentan combined with Tadalafil (WMD=46.67, 95%CI=15.88-77.45), Bosentan (WMD=29.44, 95%CI=5.86-53.02), Ambrisentan (WMD=23.90, 95%CI=0.31-47.48) and Macitentan (WMD=21.57, 95%CI=2.45-40.69). According to SUCRA, the effects of different intervention measures on improving 6MWD in patients with arterial pulmonary hypertension were as follows: Bosentan+Sildenafil (82.9%)>Bosentan+Tadalafil (78.4%)>Ambrisentan+Tadalafil (77.1%)>Bosentan (49.2%)>Sildenafil (48.5%)>Ambrisentan (40.3%)>Macitentan (37.3%)>Tadalafil (33.0%)>Placebo (3.3%). For the WHO functional class, Sildenafil (OR=2.90, 95%CI=1.04-8.08) was optimal compared with placebo, followed by Bosentan (OR=2.15, 95%CI=1.15-4.04), and there was no significant difference in the rest. For clinical worsening, Bosentan combined with Tadalafil (OR=0.08, 95%CI=0.01-0.49) performed best compared with placebo, followed by Bosentan (OR=0.20, 95%CI=0.11-0.38), Bosentan combined with Sildenafil (OR=0.21, 95%CI=0.09-0.46), Ambrisentan combined with Tadalafil (OR=0.27, 95%CI=0.15-0.50), Sildenafil (OR=0.33, 95%CI=0.17-0.66) and Tadalafil (OR=0.44, 95%CI=0.21-0.90). There was no statistical difference between all interventions and placebo in terms of the incidence of adverse events and serious adverse events. For case fatality rate, Ambrisentan (OR=0.28, 95%CI=0.11-0.74) was statistically superior to placebo and there was no statistics difference in the rest. Conclusions: The combination therapy of ERAs and PDE5i performed well in the short-term improvement of motor function. Furthermore, there was no significant difference with monotherapy in terms of safety. However, it is worth emphasizing that the choice of treatment should be based on the patient's individualized situation and the patient's requirements.

Effects of dietary protein restriction followed by realimentation on growth performance and liver transcriptome alterations of lamb.

The present study aimed to investigate the compensatory effect of early protein restriction followed by a realimentation on growth performance of lamb and to explore the transcriptomic changes in liver. Thirty-two lambs with an initial birth weight of 2.3 ± 0.20 kg that were weaned on day 15 were randomly divided into two groups. The lambs were fed a basal diet with normal protein level (NPL, protein level in the milk replacer and starter, 25 and 21%, respectively) or low protein level (LPL, protein level in the milk replacer and starter, 19 and 15%, respectively) from 15 to 60 d, after which all lambs consumed the same diet with a normal protein level from 61 to 90 d. Protein restriction led to a significant decrease in average daily gain (ADG), body weight and liver weight (P < 0.05). Transcriptome analysis showed that 302 or 12 differentially expressed genes (DEGs) were identified during the restriction or recovery periods, respectively (P < 0.05). The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated that DEGs enriched in nutrient metabolism and antioxidant capacity were down-regulated, while vessel development and immunity response-related genes up-regulated. The genes involved in metabolism of tyrosine were still down-regulated in the realimentation phase. Studies in this area indicated the accelerated growth effect of early protein restriction followed by a realimentation on growth performance of lambs and explored the transcriptomics change of liver which can help to develop feeding strategies to optimize the use of feedstuffs and in providing a new perspective for the study of early nutrition and epigenetics in later life.

[Clinical analysis of 3 cases of eosinophilic granulomatosis with polyangiitis].

Objective: To improve the clinical recognition of eosinophilic granulomatosis with polyangiitis(EGPA) in clinical manifestations, diagnosis and treatment. Methods: The clinical manifestations, pathological characteristic, imaging manifestations, diagnosis and the therapy of three patients with EGPA were presented. Results: These 3 patients had asthma-like symptoms and extrapulmonary manifestations of systemic vasculitis. They were 20, 40 and 44 years old. All of them were female.They denied exposure or contact. Chest radiographic examination showed that the most common features were nodule shadow and tree-in-bud in the lung. The pathological manifestation was characterized by hypereosinophilia, high total IgE(over 300 KU/L) and high CRP(over 14.1mg/L). The FeNO of 2 patients was over 100ppb. The ANCA of these 3 patients was negative. The pulmonary pathology was observed had eosinophil infiltration in the alveolar, interstitial and vessel for 3 cases. The clinical manifestations were nonspecific. All patients were treated by glucocorticoid and immune-inhibitor(alkylating agents or purine synthesis inhibitors) therapy. Because patients were complicated with other organs involved, they needed long-time treatment. Conclusions: This disease is diverse and complex, with a lack of pathognomonic symptoms. We should highly suspect eosinophilic granulomatosis with polyangiitis, when the patients present severe asthma and eosinophilia. Early detection, early treatment, and the prognosis could be better.

[Effect of HCO3- level on the accuracy of NoSAS screening for obstructive sleep apnea hypopnea syndrome].

Objective: To evaluate the effect of arterial blood HCO3- level on the accuracy of NoSAS questionnaire screening for obstructive sleep apnea hypopnea syndrome (OSAHS). Methods: The hospitalized patients with suspected OSAHS were recruited from March 2016 to December 2017 in the First Affiliated Hospital of Guangzhou Medical University. NoSAS scores, blood gas analysis and polysomnography (PSG) were performed in these patients. Patients were divided into non OSAHS group and mild, moderate and severe OSAHS group according to the PSG results. According to the NoSAS questionnaire score, the patients were divided into OSAHS high-risk group and low risk group. The correlation between arterial blood HCO3- level and apnea hypopnea index (AHI) was analyzed. The receiver operating characteristic (ROC) curve was plotted to analyze the accuracy of HCO3- prediction OSAHS. Predictive parameters(sensitivity, specificity, positive and negative predictive values)for NoSAS scores and HCO3- level were calculated. Results: A total of 243 patients with suspected OSAHS were included, including 186 males (76.5%), 57 females (23.5%), age (49±13) years, body mass index (BMI) (26.9±4.4) kg/m2, and neck circumference (38.6±4.5) cm. The HCO3- level was positively correlated with AHI (r=0.206, P=0.001). The proportion of patients with HCO3- level ≥26 mmol/L in non-OSAHS group was lower than that in OSAHS group (13.0% vs 34.5%, P=0.004); the proportion of patients with HCO3- level ≥26 mmol/L in severe OSAHS group was higher than that in mild OSAHS group (37.7% vs 15.0%, P=0.008), and there was no difference in the ratio of patients with severe OSAHS and moderate OSAHS (37.7% vs 35.3%, P=0.767). The specificity of OSAHS predicted by HCO3- level 25 and 26 mmol/L was 69.6% and 87.0%, respectively. With the NoSAS score of 8 or 7 as cutoffs for analysis, the sensitivity for OSAHS was 61.9% and 79.2%, the specificity for OSAHS was 57.4% and 40.4%, respectively. With the addition of HCO3- level ≥ 26 mmol/L to the NoSAS score ≥ 7, the specificity for OSAHS improved to 93.6%, while the sensitivity decreased to 27.4%. Conclusion: Combined with the arterial blood HCO3- level, the specificity of the NoSAS questionnaire increases and the sensitivity decreases.

[Analysis of the characteristics of electrocardiogram in patients of different genders with pulmonary hypertension].

Objective: To analyze the characteristics of ECG in patients with pulmonary hypertension(PH) and explore their correlation with pulmonary vascular resistance(PVR), mean pulmonary arterial hypertension(mPAP) and cardiac index(CI). Methods: A total of 186 patients with right heart catheterization were enrolled in the Department of Respiratory of the First Affiliated Hospital of Guangzhou Medical University from August 2015 to October 2017. Patients with normal pulmonary artery pressure, incomplete clinical data and repeated examinations were excluded and there were 101 patients with pulmonary hypertension included. The results of ECG parameters and right heart catheterization were collected to analyze the ECG characteristics of patients with different genders and their correlation with PVR, mPAP and CI. Results: Among all PH patients, the duration of QRS axial in male group was significantly longer than that of the female group [(110.38±15.829) vs. (98.63±18.041) ms, P<0.001], and the S wave amplitude in V5 was significantly higher compared to female group [(1.304±1.356) vs. (0.648±0.663) mv, P<0.001]. Their heart rate-corrected QT interval (QTc), QRS axis, S wave amplitude in Ⅰ, S and R wave amplitude in V1, R/S ratio in V1, S wave amplitude V5, all had a correlation with their PVR and the S wave amplitude in V1 was negatively correlated with PVR (r=-0.441, P<0.001). In the male group, PVR was not correlated with R/S ratio in V1 and S wave amplitude in V5. While PVR in the female group was significantly correlated with QTc, R wave amplitude in V1, R / S ratio in V1. In all PH patients, their P wave duration in Ⅱ, QRS axis and S wave amplitude in Ⅰ, S wave and R wave amplitude in V1, S wave amplitude in V5, QTc, R/S ratio in V1, all had correlations with mPAP (P<0.05). In male group, mPAP was not correlated with QTc, P wave duration in Ⅱ, and the S wave amplitude in V5 (P>0.05). The mPAP in the female group was only related to the S wave and R wave amplitude in V1, and S amplitude in Ⅰ and S wave amplitude in V5 (P<0.05). The CI was positively correlated with the S wave amplitude in V1 (r=0.34, P<0.001), and negatively correlated with the QRS axis (r=-0.219, P=0.04); CI in male group was not correlated with QRS axis(P=0.073), but correlated with QTc (r=-0.296, P=0.044). Conclusion: There were gender differences in QRS duration and S wave amplitude in V5 in patients with pulmonary hypertension. The QRS axis and the S wave amplitude in V1 were related to the heart index. There was a difference in the correlation between ECG and PVR, mPAP and CI in patients of different genders with pulmonary hypertension.

[Comparison of the NoSAS score with four different questionnaires as screening tools for obstructive sleep apnea-hypopnea syndrome].

Objective: To evaluate the clinical utility of the NoSAS score in the screening of patients with obstructive sleep apnea-hypopnea syndrome(OSAHS), and to compare the performance of the NoSAS score with other tools including Epworth Sleepiness Scale(ESS), STOP, STOP-Bang(SBQ) and Berlin questionnaires. Methods: A total of 444 consecutive patients(328 males and 116 females) with suspected OSAHS who underwent an overnight polysomnography(PSG) were recruited into this study. Five questionnaires including the NoSAS score, ESS, STOP, SBQ and Berlin were completed. Based on the severity of OSAHS which was determined by apnea-hypopnea index(AHI), the patients were classified into 4 groups: normal(<5 events/h), mild(5-15 events/h), moderate(15-30 events/h) and, severe (≥30 events/h) OSA.Sensitivity, specificity, positive predictive values, negative predictive values and the area under the receiver operating characteristics curve of 5 questionnaires were calculated. Results: With AHI≥5 events/h as the standard diagnosis of OSAHS, the NoSAS score and SBQ questionnaire showed a moderate performance, with the NoSAS score having the largest area under the ROC curve(0.753, P<0.001), followed by the SBQ questionnaire (0.727, P<0.001). The performance of the ESS, Berlin, and the STOP questionnaire was not high. Using mild moderate-severe(≥5 events/h), moderate-severe(≥15 events/h), and severe(≥30 events/h)OSAHS as cutoffs, NoSAS had the highest specificity and positive predictive values(80.2% and 88%, 72% and 69.8%, 66.3% and 50.5%), and the sensitivity and negative predictive values were (51.5% and 36.9%, 56.5% and 59.1%, 66.3% and 74.2%) .SBQ had the highest sensitivity and the negative predictive values(80.2% and 88%, 72% and 69.8%, 66.3% and 50.5%), and the specific and positive predictive values were (45.7% and 81.0%, 39.1% and 61.9%, 34.8% and 44.4%). The NoSAS score ≥ 7 had higher sensitivity and negative predictive value(75.0% and 47.1%, 78.1% and 66.5%, 82.7% and 81.9%)than the NoSAS socre ≥ 8. With AHI≥5 events/h as the standard diagnosis of OSAHS, the NoSAS score and the SBQ questionnaire had a higher accuracy than the other 3 questionnaires as screening questionnaires for diagnosing OSAHS, and the value of DOR were 4.298 and 3.758 respectively. Conclusions: The NoSAS score and the SBQ questionnaire have a moderate performance in diagnosing OSAHS. The NoSAS score is a new screening tool, and it is similar to the SBQ questionnaire, being also simple and effective. While the SBQ questionnaire is more widely used, it is necessary to further evaluate the diagnostic value of NoSAS score.

[Correlation between peripheral venous oxygen saturation and hemodynamic parameters in patients with pulmonary hypertension].

Objective: To investigate the correlation of peripheral venous oxygen saturation (SpvO(2)) with mixed venous oxygen saturation (SvO(2)), pulmonary vascular resistance (PVR) and cardiac index (CI) in patients with pulmonary hypertension (PH), in order to predict these parameters using SpvO(2) and assess the prognosis of patients. Methods: Hospitalized patients diagnosed with PH by right heart catheterization in the Guangzhou Institute of Respiratory Diseases from July 2015 to October 2016 were retrospectively analyzed. Parameters during the right heart catheterization, including SvO(2,)SpvO(2,)cardiac output (CO) and mean pulmonary arterial pressure (mPAP) were recorded, while CI, PVR and other parameters were indirectly calculated. The correlation between SpvO(2) and SvO(2,)CO, CI, mPAP, PVR and other parameters were respectively analyzed and compared between groups. Results: A total of 77 PH patients were selected, which comprised of 39 males and 38 females. The results revealed that SpvO(2) was correlated positively with SvO(2,)CI and PaO(2) (P<0.05), but negatively with PVR, total pulmonary resistance (TPR), systemic vascular resistance, right atrial diameter and right ventricular diameter (P<0.05). In the group with SpvO(2) <65%, the dilation of the right atrium and right ventricle was more significant, the WHO heart function grade was worse, CI, systemic systolic pressure and mean systemic pressure were lower, and PVR and TPR were higher, as compared to those in the group with SpvO(2) ≥65%. (P<0.05). Conclusions: There was good consistency between SpvO(2) and SvO(2). Furthermore, SpvO(2) could indirectly reflect the CI, PVR and changes in right heart structure of PH patients, providing reference for the clinical prediction of CI and PVR, as well as the prognosis of PH patients, through the use of SpvO(2). Low SpvO(2) indicated a severe condition and poor prognosis.

[Individual difference of coronal bowing of femur and its influence on the lower limbs alignment after the total knee arthroplasty].

Objective: To disclose the correlation between the femur bowing angle(FBA) and vulgas correction angle(VCA), anlysys its influence on the total knee arthroplasty and the lower limbs alignment. Methods: From Janurary 2013 to December 2015, 699 patients who had received total knee arthroplasty(TKA)were collected in the Department of Joint Surgery, China-Japan Friendship. The FBA, VCA, offset of the proximal femur, the lengh of the femur, the neck shaft angle of the femur of the eligible cases from the long leg X-ray were measured.All the data were analysed for the following steps: the FBA's mean value and characteristics of distributation of all the cases; the VCA's mean value and characteristics of distributation of all the cases; correlations between the VCA and the other parameters; divide all the cases into four groups based on the value of FBA : group A(FBA<-3°, 29), group B(-3°≤FBA≤0°, 255), group C(0°3°, 236)and then plan to cut the distal femur with 5° and 6°, respectively. The percent of ideal alignmental outcome's percentage of every group were compared. Results: The mean Value of the FBA is -7.1--12.1(1.4±2.4)°; the mean Value of the VCA is 2.5--11.9(6.5±1.3)°. The correlation index between VCA and FBA, the neck shaft angle of the femur , offset of the hip joint, the lengh of the femur is 0.72, -0.26, 0.45 and -0.08, perspectively. The theoretical ideal alignment percentage of the 5 degree-valgus-bone cut and 6 degree-valgus-bone cut in every group is group A: 89.7% and 66.5%; group B: 93.7% and 95.7%; group C: 71.9% and 94.6%; group D: 21.2% and 50.8%, respectively. Conclusion: The cases whose femur bowing angles are outliers are common in daily medical practice, so the vulgas correction angles need be ajusted for its significant correlation with FBA. 5 degree-valgus-bone cut or 6 degree-valgus-bone cut could not get the ideal alignment some times.

[Severe obstructive sleep apnea-hypopnea syndrome with dilated cardiomyopathy leading to pulmonary hypertension: case report and literature review].

Objective: To study the relationship between dilated cardiomyopathy and obstructive sleep apnea-hypopnea syndrome (OSAHS) and to evaluate the curative effects of continuous positive airway pressure (CPAP) in OSAHS complicated with dilated cardiomyopathy. Methods: We reported one case with the symptom of exertional dyspnea for 1 year and aggravating for 1 month. The patient finally was diagnosed with severe OSAHS complicated with dilated cardiomyopathy leading to pulmonary hypertension. A systematic literature review was performed for similar published cases in Pubmed, Wanfang and CNKI database, using the keywords (obstructive sleep apnea) OR(OSA) OR(OSAHS) AND(dilated cardiomyopathy OR DCM)from January 1990 to May 2016. Results: Our patient had no significant improvement after receiving initial treatments, including reducing cardiac preload, improving myocardial metabolism, increasing myocardial contractility, and anticoagulants. After the patient was diagnosed as having severe OSAHS by polysomnography(PSG) and treated with CPAP, his symptoms improved remarkably. The enlarged heart became smaller and the patient had no repeated dyspnea at follow-up examination. By literature review, we found 4 English original articles and 6 Chinese articles (1 review article, 1 expert note, 1 original article and 3 case reports) on OSAHS complicated by DCM.Four Chinese and 1 English articles reported that the symptoms and parameters of OSAHS with DCM was improved remarkably after treatment with CPAP. Conclusion: For patients with dilated cardiomyopathy which fails to conventional therapy, especially those accompanied by obesity, snoring, daytime sleepiness, morning dry mouth and other related symptoms, PSG should be carried out. Early CPAP therapy could improve symptoms and prognosis of OSAHS associated with DCM.

Feeding different dietary protein to energy ratios to Holstein heifers: effects on growth performance, blood metabolites and rumen fermentation parameters.

Eighteen Chinese Holstein heifers average age 230 ± 14 days were allocated to 1 of 3 dietary crude protein (CP) to metabolizable energy (ME) ratios to examine the effects on growth performance, blood metabolites and rumen fermentation parameters with 90-days experiment. Three different dietary CP:ME ratios were targeted based on the formulation of dietary CP contents of 10.85%, 12.78% and 14.63% on dry matter (DM) basis with similar ME contents (10.42 MJ/kg DM), which were categorized as low, medium and high dietary CP:ME ratios. The actual CP:ME ratios obtained in this study significantly increased from low to high CP:ME ratio groups with a value of 10.59, 11.83 and 13.38 g/MJ respectively. Elevated CP:ME ratios significantly increased CP intake (kg/day) and feed efficiency (FE) which was defined as dry matter intake as a proportion of average daily gain (ADG), whereas little difference was observed in body weight (kg), ADG (kg/day), DM intake (kg/day) and ME intake (MJ/day) among the three different CP:ME ratio groups. Increasing dietary CP to ME ratios significantly increased CP digestibility, whereas digestibility of DM and gross energy remained constant in the current experiment. Blood urea nitrogen and insulin-like growth factor-1 linearly increased with increasing dietary CP:ME ratios. There was significantly dietary treatment effect on rumen fermentation parameters including acetate, propionate, butyrate and total volatile fatty acids. Therefore, this study indicated that increasing dietary CP levels with similar energy content contributed to increased protein intake and its digestibility, as well as FE. Holstein heifers between 200 and 341 kg subjected to 13.38 dietary CP:ME ratio showed improved feed efficiency, nutrient digestibility, some blood metabolites and rumen fermentation characteristics for 0.90 kg/day rate of gain.

Influence of dietary slow-release urea on growth performance, organ development and serum biochemical parameters of mutton sheep.

Eighty Dorper × thin-tailed Han cross-bred non-castrated male lambs [mean body weight (BW), 25.87 ± 1.06 kg] were randomly allocated to one of five different concentrations of slow-release urea (urea phosphate, UP). The feed consisted of an equal amount of concentrate diet and roughage; the concentrate feed was formulated to be isoenergetic and isonitrogenic and contained 0%, 1%, 2%, 4% and 8% UP (UP0.0, UP1.0, UP2.0, UP4.0 and UP8.0, respectively) as a replacement for soya bean meal. Feed intake, BW, average daily gain (ADG), feed utilisation efficiency (FUE), absolute and relative organ weights and biochemical and histopathological parameters were measured. Feed intake, BW, ADG and FUE significantly decreased in the group receiving UP8.0 (p < 0.05), but no difference was found among the other groups (p > 0.05). Quadratic equations were developed between the UP dosage in the concentrate feed and ADG or FUE (r2  = 0.973 for ADG and r2  = 0.761 for FUE) to determine the appropriate dosage of UP given the desire to maximise either ADG or FUE, the appropriate dosage (feed concentration) was calculated as 2.01% UP to achieve the greatest ADG or 2.13% UP to achieve the best FUE. The relative weight of the liver (% BW) in the UP2.0 groups was significantly greater than that of UP0.0 (p < 0.05), and the relative weight of the intestine in the UP8.0 was significantly greater than that of UP0.0 (p < 0.05); the relative weight of the carcass, heart, spleen, lung, kidney, rumen, reticulum, omasum and abomasum did not differ among treatments (p > 0.05). The UP8.0 treatment significantly increased serum phosphorus levels (p < 0.05) and decreased the levels of alkaline phosphatase, glucose and calcium (Ca) compared with the lower UP dosage (p < 0.05). No histopathological differences were found in either hepatic tissues or renal tissues among treatments. Dietary UP as a replacement for soya bean in concentrate feeds for mutton sheep should not exceed 4%, as higher dosing may cause malnutrition and mineral disorders.

Energy requirements of early-weaned Dorper cross-bred female lambs.

The net and metabolizable energy (NE and ME) requirements of Dorper cross-bred female lambs with BWs of 20-35 kg were assessed in a comparative slaughter trial. Thirty-five Dorper × thin-tailed Han cross-bred female lambs weaned at ~50 days of age (20.3 ± 2.15 kg BW) were used. Seven randomly selected lambs were slaughtered at the start of the trial (baseline group). An intermediate group consisting of seven randomly selected lambs fed ad libitum was slaughtered when the lambs reached an average BW of 28.5 kg. The remaining 21 lambs were allotted randomly to three levels of dry matter intake: ad libitum or restricted to 70% or 40% of the ad libitum intake. All the lambs were slaughtered when the sheep fed ad libitum reached a BW of 35 kg. Total body energy, nitrogen, fat, ash and moisture content were determined. In a digestibility trial, an additional 15 Dorper × thin-tailed Han cross-bred female lambs (28.7 ± 1.75 kg BW) were housed in metabolism cages and used in a completely randomized design experiment to evaluate the ME value of the diet at the three feed intake levels. The maintenance requirements for NE and ME were 245.5 and 380.3 kJ/kg metabolic shrunk body weight (SBW0.75 ) respectively. The partial efficiency of energy use for maintenance was 0.645. The NE requirements for growth ranged from 1.18 to 5.18 MJ/d for the lambs gaining 100-350 g/d from 20 to 35 kg BW. Partial efficiency of ME for growth was 0.44. In conclusion, the current study suggests that the NE requirement for maintenance and growth of Dorper early-weaned cross-bred female lambs is lower than the current AFRC and NRC recommendations.

Effect of oral administration of probiotics on growth performance, apparent nutrient digestibility and stress-related indicators in Holstein calves.

This study aimed to investigate the effect of dietary supplementation with Lactobacillus plantarum and Bacillus subtilis on growth performance, apparent nutrient digestibility and stress-related indicators in dairy calves. Twenty-four neonatal Holstein calves were randomly allocated to three treatments: a basal diet with no supplementation (control), the basal diet supplemented with 1.7 × 10(10) CFU per head per day (CFU/h.d) of L. plantarum GF103 (LB group) or the basal diet supplemented with a mixture of L. plantarum GF103 (1.7 × 10(10) CFU/h.d) and B. subtilis B27 (1.7 × 10(8) CFU/h.d) (LBS group). Dry matter intake (DMI), average daily gain (ADG), feed conversation ratio (FCR), apparent digestibility of nutrients and stress-related indicators were measured in this trail. The result indicated that no significant differences were observed in DMI or ADG (p > 0.05), but the FCR was improved in the LB group over the first 12 weeks (p > 0.05). The apparent digestibility of nutrients was not altered by probiotics in week 6 (p > 0.05), but the apparent digestibility of total phosphorus was significantly greater in the LB and LBS groups in week 8 (p > 0.05); additionally, an increase in the apparent digestibility of crude protein was detected in the LBS group (p > 0.05). Oral administration of L. plantarum alone improved the T-lymphocyte transformation rate on days 58 and 62 (p > 0.05), while adding the mixture of L. plantarum and B. subtilis increased the T-lymphocyte transformation rate (p > 0.05) but decreased the content of cortisol on day 58 (p > 0.05). No significant differences were detected between the LB and LBS groups in growth performance, apparent digestibility of nutrients and stress-related indicators (p > 0.05). The results suggested that oral administration of L. plantarum improved growth performance, nutrient digestibility and relieved weaning stress in calves, but no additional effect was obtained by supplementation with B. subtilis.

Effect of the Ratio of Non-fibrous Carbohydrates to Neutral Detergent Fiber and Protein Structure on Intake, Digestibility, Rumen Fermentation, and Nitrogen Metabolism in Lambs.

This study aimed to investigate the effect of the ratio of non-fibrous carbohydrates to neutral detergent fibre (NFC/NDF) and undegraded dietary protein (UDP) on rumen fermentation and nitrogen metabolism in lambs. Four Dorper×thin-tailed Han crossbred lambs, averaging 62.3±1.9 kg of body weight and 10 mo of age, were randomly assigned to four dietary treatments of combinations of two levels of NFC/NDF (1.0 and 1.7) and two levels of UDP (35% and 50% of crude protein [CP]). Duodenal nutrient flows were measured with dual markers of Yb and Co, and microbial N (MN) synthesis was estimated using (15)N. High UDP decreased organic matter (OM) intake (p = 0.002) and CP intake (p = 0.005). Ruminal pH (p<0.001), ammonia nitrogen (NH3-N; p = 0.008), and total volatile fatty acids (p<0.001) were affected by dietary NFC/NDF. The ruminal concentration of NH3-N was also affected by UDP (p<0.001). The duodenal flow of total MN (p = 0.007) was greater for lambs fed the high NFC/NDF diet. The amount of metabolisable N increased with increasing dietary NFC:NDF (p = 0.02) or UDP (p = 0.04). In conclusion, the diets with high NFC/NDF (1.7) and UDP (50% of CP) improved metabolisable N supply to lambs.

Effect of dietary supplementation of rutin on lactation performance, ruminal fermentation and metabolism in dairy cows.

The effect of long-term dietary supplementation with rutin on the lactation performance, ruminal fermentation and metabolism of dairy cows were investigated in this study. Twenty multiparous Chinese Holstein cows were randomly divided into four groups, and each was offered a basal diet supplemented with 0, 1.5, 3.0 or 4.5 mg rutin/kg of diet. The milk yield of the cows receiving 3.0 and 4.5 mg rutin/kg was higher than that of the control group, and the milk yield was increased by 10.06% and 3.37% (p < 0.05). On the basis of that finding, the cows supplemented with 0 or 3.0 mg rutin/kg of diet were used to investigate the effect of rutin supplementation on blood metabolites and hormone levels. Compared with the control group, the serum blood urea nitrogen (BUN) concentration of the 3.0 mg rutin/kg group is significantly decreased (p < 0.05). In another trial, four adult cows with permanent rumen fistula and duodenal cannulae were attributed in a self-control design to investigate the peak occurrence of rutin and quercetin in different parts of the gastrointestinal tract, ruminal fermentation and microbial population in dairy cows. The cows supplemented with 3.0 mg rutin/kg in the diet differed from the control period. Samples of rumen fluid, duodenal fluid and blood were collected at 1, 2, 3, 4, 5, 6, 7 and 8 h after morning feeding. Compared to the control group, the pH, ammonia nitrogen concentration, number and protein content of rumen protozoa and blood urea nitrogen were lower, but the concentration of total volatile fatty acid (TVFA), microbial crude protein (MCP) and serum lysozyme content were higher for the cows fed the rutin diets. The addition of 3.0 mg rutin/kg to diets for a long term tended to increase the milk yield and improve the metabolism and digestibility of the dairy cows.

Effect of dietary supplementation with resveratrol on nutrient digestibility, methanogenesis and ruminal microbial flora in sheep.

Two experiments were conducted to evaluate the effect of resveratrol on methanogenesis and microbial flora in Dorper × thin-tailed Han cross-bred ewes. In experiment 1, ten ewes (67.2 ± 2.24 kg BW) were assigned to two dietary treatments, a basal diet and a basal diet supplemented with resveratrol (0.25 g/head·day), to investigate the effect of resveratrol on nutrient digestibility and nitrogen balance. In experiment 2, six ewes (64.0 ± 1.85 kg BW) with ruminal cannulae were assigned to the identical dietary treatments used in experiment 1 to investigate supplementary resveratrol on ruminal fermentation and microbial flora using qPCR. The results showed that supplementary resveratrol improved the digestibility of organic matter (OM; p < 0.001), nitrogen (N; p = 0.007), neutral detergent fibre (NDF; p < 0.001) and acid detergent fibre (ADF; p < 0.001). The excretion of faecal N was reduced (p = 0.007), whereas that of urinary N increased (p = 0.002), which led to an unchanged N retention (p = 0.157). Both CO2 and CH4 output scaled to digestible dry matter (DM) intake decreased from 602.5 to 518.7 (p = 0.039) and 68.2 to 56.6 (p < 0.001) respectively. Ruminal pH (p = 0.341), ammonia (p = 0.512) and total volatile fatty acid (VFA) (p = 0.249) were unaffected by resveratrol. The molar proportion of propionate increased from 13.1 to 17.5% (p < 0.001) while that of butyrate decreased from 11.0 to 9.55% (p < 0.001). The ratio of acetate to propionate (A/P) decreased from 5.44 to 3.96 (p < 0.001). Supplementary resveratrol increased ruminal population of Fibrobacter succinogenes, Ruminococcus albus and Butyrivibrio fibrisolvens (p < 0.001) while decreased protozoa and methanogens. In conclusion, dietary resveratrol inhibited methanogenesis without adversely affecting ruminal fermentation.