Effects of Moringa oleifera silage on milk yield,nutrient digestibility and serum biochemical indexes of lactating dairy cows

This study investigated the effects of Moringa oleifera (MO) as a partial substitute of alfalfa hay on milk yield, nutrient apparent digestibility and serum biochemical indexes of dairy cows. MO was harvested at 120 days post‐seeding. Fresh MO was cut, mixed with chopped oat hay (425:575 on a DM basis), ensiled and stored for 60 days. Sixty healthy Holstein dairy cows were allocated to one of three groups: NM (no MO or control), LM (low MO; 25% alfalfa hay and 50% maize silage were replaced by MO silage) or HM (high MO; 50% alfalfa hay and 100% maize silage were replaced by MO silage). The feeding trial lasted 35 days. The LM and HM diets did not affect dry matter (DM) intake, milk yield or milk composition (lactose, milk fat, milk protein and somatic cell count). The apparent digestibility of DM and NDF was lower for HM group than NM group. Additionally, there were no significant differences in serum biochemical indexes between the LM and NM groups. The HM group had lower serum concentrations of total cholesterol, high‐density lipoprotein cholesterol, and low‐density lipoprotein cholesterol and higher serum concentrations of urea than the NM group. The partial replacement of alfalfa hay (≤50%) and maize silage with MO silage had no negative effects on milk yield, in vivo nutrient apparent digestibility or serum biochemical indexes of lactating cows.     

三峡库区消落带不同海拔狗牙根草地土壤微生物生物量碳氮磷含量特征

为探究库区消落带优势草本植物狗牙根人工植被恢复后土壤质量及肥力的变化,选择三峡库区消落带150, 160和170 m海拔人工构建狗牙根植被土壤为研究对象,并以裸地作为对照,测定土壤微生物生物量碳、氮、磷和相关理化性质。结果表明:(1)各海拔狗牙根微生物生物量均显著高于裸地,表明狗牙根人工植被构建对土壤微生物恢复具有重要意义。(2)土壤微生物生物量碳、氮含量160 m高程显著高于150和170 m高程,但土壤微生物生物量磷(SMBP)却显著低于150和170 m高程,需要特别注意P元素的下移,加强水体P含量的检测。(3)土壤微生物生物量碳氮比和碳磷比变化范围分别为5.93~15.62和7.11~19.99,土壤微生物生物量碳、氮、磷占土壤有机碳、全氮、全磷百分比的范围分别为0.68%~2.57%、0.68%~3.33%、1.95%~5.23%。狗牙根土壤微生物生物量碳氮比和碳磷比显著低于裸地,表明狗牙根土壤有效氮、有效磷高于裸地;土壤微生物生物量碳、氮、磷占土壤有机碳、全氮、全磷百分比显著高于裸地,表明狗牙根土壤营养元素周转速率快于裸地。(4)微生物生物量碳、氮、磷与土壤有机碳、全氮和土壤含水率有显著或极显著相关性,与土壤pH值呈不同程度的负相关。因此,在三峡库区消落带进行狗牙根草地恢复重建能显著提高土壤微生物生物量及土壤质量,对加强三峡库岸生态系统的稳定性具有重要意义。     

野榆钱菠菜三种异型种子幼苗的生长特性

野榆钱菠菜是新疆重要的荒漠野生牧草资源,具有褐色(非休眠类型)、黑色大、黑色小(休眠类型)3种异型种子。以种子异型性植物野榆钱菠菜为材料,对3种异型种子在自然条件下进行培育,对比观察研究3种异型种子的萌发物候及幼苗的生长特性。结果表明:1) 异型种子萌发物候不同步,萌发策略不同,褐色种子集中萌发,出苗率为74.30%,萌发期为3 d;两种黑色种子萌发期长,分散萌发,出苗率分别为6.58%(黑色大种子)和1.55%(黑色小种子),萌发期分别为21和17 d。2) 异型种子子叶存留时间长,但存留时间有差异,种子越小子叶存留时间越短。3) 褐色种子幼苗在初期其子叶长宽、根长、地上地下生物量均显著大于黑色种子幼苗,但随着幼苗的生长,3种异型种子幼苗在这些指标方面的差异逐渐缩小。4) 异型种子幼苗具有不同的生物量分配策略,褐色种子幼苗主要将养分输送到地上部分,两种黑色种子幼苗主要将养分输送到地下部分,这种不同的生物量分配策略能够使种子异型性植物在面对荒漠异质环境时具有不同的应对方式,是种子异型性植物能够长期适应荒漠异质环境的重要生态适应机制。研究结果为揭示种子异型性植物长期适应荒漠异质环境提供新的科学依据,也为“两头下注”对策理论提供新的理论基础。     

The complete mitochondrial genome and molecular phylogeny of Lueyang black-bone chicken

ABSTRACT

1. The objectives of the current study were to investigate the mitochondrial genome and molecular phylogeny of Lueyang black-bone chicken, and provide molecule base to preserve and explore the specific chicken strain.

2. Based on sequencing and clustering, the complete mitochondrial DNA map and sequences of Lueyang black-bone chicken were revealed, and two phylogenetic trees of Lueyang black-bone chickens based on D-loop sequences and the mitochondrial genome were constructed.

3. The results showed that the complete mitochondrial genome of Lueyang black-bone chickens is 16,784bp in size, consisting of 22 transfer RNA genes, two ribosomal RNA genes, 13 protein-coding genes, and one non-coding control region. The base composition of the complete mtDNA sequence is 30.28% for A, 23.78% for T, 32.42% for C, 13.52% for G. Additionally, 10 haplotypes of D-loop sequences in 32 Lueyang black-bone chickens were detected, which were distributed into 4 clades (A, B, C and E).

4. It was concluded that genetic diversity is wide in Lueyang black-bone chickens, and this strain has multiple maternal origins from different regions in China and neighbouring regions.     

Inclusion levels and modes of whole grain incorporation into wheat-based rations differentially influence the performance of broiler chickens

1. The objective was to compare three whole grain (WG) inclusion levels (7.5, 15 and 30%) offered to broiler chickens by three modes of WG incorporation: (i) pre-pellet WG inclusion, (ii) post-pellet WG inclusion as a blend of WG and pelleted concentrate and (iii) post-pellet WG inclusion where WG and pelleted concentrate were provided in separate feed trays against a ground-grain, wheat-based control diet.

2. Ten dietary treatments were offered to 6 replicate cages (6 birds per cage) of male Ross 308 chickens from 7 to 28 d post-hatch. The effects of treatment on relative gizzard weights, gizzard contents, pancreatic weights and pH of gizzard digesta were monitored. Parameters of growth performance, nutrient utilisation (apparent metabolisable energy [AME], metabolisable to gross energy [ME:GE] ratios, nitrogen [N] retention and N-corrected AME [AMEn]), apparent starch and protein (N) digestibility coefficients and disappearance rates in for small intestinal segments and concentrations of free amino acids in plasma taken from the anterior mesenteric vein were determined.

3. Whole grain feeding (WGF) did not influence weight gain, but 30% post-pellet blended and 15 and 30% post-pellet separated treatments significantly depressed (P < 0.05) feed intakes while the 30% post-pellet separated treatment improved (P < 0.01) feed conversion ratios (FCR). WGF regimes significantly increased relative gizzard weights.

4. Overall, WGF generated profound responses in AME, ME:GE ratios, N retention and AMEn that were highly correlated with relative gizzard weights. In general, WGF improved starch and protein (N) digestibilities and again there were some correlations with these outcomes and relative gizzard weights.

5. Post-pellet WG inclusions where WG and pelleted concentrate were offered separately provided chickens with the opportunity to choice feed. Birds showed a preference for the relatively high-protein pelleted concentrate and at 30% WG, this resulted in an improvement in FCR of 7.69% (1.260 versus 1.365; P < 0.001) relative to the ground-grain control diet.     

Polyphenols in Eucalyptus leaves improved the egg and meat qualities and protected against ethanol‐induced oxidative damage in laying hens

Polyphenols in Eucalyptus leaves (PE) were value resources due to various pharmacological activities, but data on the effect on laying hens are very scare. This study was conducted to determine the effect of PE on the laying performance, egg traits, meat quality, antioxidant status and liver tissues of laying hens. One hundred and twenty 256‐day‐old Yueqinhuang laying hens were randomly assigned to four treatment groups (different levels of PE at 0, 0.5, 0.8 and 1.2 g/kg diet) for 63 days with 15 replicates per group. Addition of 0.8 g/kg PE not only improved the egg trait by increasing the eggshell thickness and decreasing MDA production and cholesterol content in the egg yolk, but also significantly enhanced meat quality of hens, as suggested by the increase pH_45 min (p < .01) and a* value, and decrease drip loss rate (p < .01). Meanwhile, under acute ethanol‐induced oxidative damage condition, supplementation of 0.8 g/kg PE enhanced the serum antioxidant status by increasing enzymatic activities (GSH‐PX, T‐SOD, T‐AOC), inhibited oxidative damage and provided protective effect to liver tissue. In conclusion, addition of 0.8 g/kg PE not only improved the egg traits and meat quality without obvious adverse effects, but also increased the serum antioxidant status of the hens and protected their liver tissue from ethanol‐induced oxidative damage. This study indicated that PE could be utilized as an effective feed additive for laying hens to improve health performance and egg traits.     

Effects of concentrate‐to‐forage ratios and 2‐methylbutyrate supplementation on ruminal fermentation,bacteria abundance and urinary excretion of purine derivatives in Chinese Simmental steers

This study evaluated the effects of dietary concentrate levels and 2‐methylbutyrate (2MB ) supplementation on performance, ruminal fermentation, bacteria abundance, microbial enzyme activity and urinary excretion of purine derivatives (PD ) in steers. Eight ruminally cannulated Simmental steers (12 months of age; 389 ± 3.7 kg of body weight) were used in a replicated 4 × 4 Latin square design with a 2 × 2 factorial arrangement. Moderate‐concentrate (400 g/kg diet [MC ]) or high‐concentrate (600 g/kg diet [HC ]) diets were fed with or without 2MB (0 g/day [2MB ?] or 15.0 g/day [2MB +]). Dry matter intake and average daily gain increased, but feed conversion ratio decreased with the HC diet or 2MB supplementation. Ruminal pH decreased, but total volatile fatty acid increased with the HC diet or 2MB supplementation. Molar proportion of acetate and acetate‐to‐propionate ratio decreased with the HC diet, but increased with 2MB supplementation. Propionate molar proportion and ruminal NH ₃‐N content increased with the HC diet, but decreased with 2MB supplementation. Neutral detergent fibre degradability decreased with the HC diet, but increased with 2MB supplementation. Crude protein degradability increased with the HC diet or 2MB supplementation. Abundance of Ruminococcus albus , Ruminococcus flavefaciens , Fibrobacter succinogenes and Bufyrivibrio fibrisolvens as well as activities of carboxymethyl cellulase, cellobiase, xylanase and pectinase decreased with the HC diet, but increased with 2MB supplementation. However, abundance of Prevotella ruminicola and Ruminobacter amylophilus as well as activities of α‐amylase and protease increased with the HC diet or 2MB supplementation. Total PD excretion also increased with the HC diet or 2MB supplementation. The results suggested that growth performance, ruminal fermentation, CP degradability and total PD excretion increased with increasing dietary concentrate level from 40% to 60% or 2MB supplementation. The observed diet × 2MB interaction indicated that supplementation of 2MB was more efficacious for improving growth performance, ruminal fermentation and total PD excretion with promoted ruminal bacteria abundance and enzyme activity in the MC diet than in the HC diet.     

Effect of gut stress induced by oxidized wheat gluten on the growth performance,gut morphology and oxidative states of broilers

This study was to investigate the effect of oxidized wheat gluten (OG) on growth performance, gut morphology and its oxidative states of broilers. One hundred and eighty‐day‐old male broilers (10 chicks/pen) were randomly allocated into three dietary treatments: control diet (CON), diet with 8% wheat gluten (WG) and diet with 8% OG with six pens/treatment. Body weight (BW) (21 and 35 days) and average daily gain (ADG) (1–21 days and 22–35 days) decreased (p < .05) and feed conversion ratio (FCR) (1–21 days and 22–35 days) increased (p < .05) in OG treatment. Feed intake (FI) decreased (p < .05) in WG and OG treatments during 22–35 days. However, FI was not influenced by dietary treatments during 1–21 days (p > .05). The OG‐fed broilers had a lower faecal pH value (p < .05) and higher faecal moisture content (p < 05) at 14, 21, 28 and 35 days. Villus height, crypt depth and V/C value were not different (p > .05) among treatments at 21 and 35 days. Lipid peroxidation (LPO) (21 and 35 days) and malondialdehyde (MDA) (35 days) content in crop of OG treatment increased (p < .05). Oxidized glutathione (GSSG) (21 days), LPO (21 and 35 days) and MDA (21 and 35 days) content in ileum of OG treatment increased (p < .05). The reduced glutathione/oxidized glutathione (GSH/GSSG) (21 days) and (GSH) (35 days) in ileum of OG treatment decreased (p < .05). The present findings indicate that OG might be a stressor for broiler gut, which could induce oxidative stress both in crop and in ileum, and the diarrhoea as well. The growth performance of broiler was consequently depressed.