妊娠后期不同营养水平限制饲养母羊对其体贮动员及利用的影响

选择经同期发情且同期受孕,在妊娠90d时健康的苏尼特母羊49只,以4种营养水平(MEMJ/kgW0.75·d):0.2(G1);0.33(G2);0.44(G3);0.86(CG),分组限制饲养,研究妊娠后期不同营养水平限制饲养母羊对其体贮动员及利用的影响。结果表明:整个限制期,CG、G3、G2、G1组母羊随着摄入外源能量的降低,分别动员了试验开始时平均母体净重的2.4%、11.3%、17.9%、27.9%,差异极显著(P<0.01)。在此期间,G1、G2、G3组的胰岛素浓度有降低的趋势。6￣34d,各组血清中游离脂肪酸浓度都不同程度的有所降低,其中G1组与G3、CG组差异显著(P<0.05),仅为262.22μmol/L。到了54d时,尽管各组血清中游离脂肪酸浓度有所回升,但仍低于限制开始时浓度。其中G1组为793.98μmol/L,而G2、G3、CG组分别为1072.29、1048.19、1011.25μmol/L。从54d到分娩后,G1组血清中游离脂肪酸浓度基本维持在同一水平,而G2、G3、CG组血清中游离脂肪酸浓度有不同程度的降低。     

The relationship between appetite and plasma non-esterified fatty acid levels in housed calves

Non-esterified fatty acid (NEFA) levels in housed, 3-month-old calves were monitored in two experiments designed to establish (i) the effect of diet and time of sampling in relation to feeding on blood levels; and (ii) the relationship between appetite and plasma NEFA in animals on chopped hay. In the first experiment, a significant drop in NEFA levels was recorded after feeding. Furthermore, the NEFA levels of calves maintained on concentrate were significantly lower than those on hay throughout the post-feeding period. In the second study, a significant negative correlation was established between NEFA levels and intake of chopped hay in (i) ad-lib-fed calves infected with the abomasal nematode Ostertagia ostertagi; (ii) worm-free animals pair-fed with those in group (i); and (iii) ad-lib-fed worm-free calves. Regression analysis of raw and transformed data from all three groups combined also yielded significant correlations. It is suggested that the measurement of blood NEFA may be a useful indirect indicator of feed intake in conditioned housed calves offered hay diets.     

Plasma leptin and mRNA expression of lipogenesis and lipolysis-related factors in bovine adipose tissue around parturition

The objective was to study changes in plasma leptin concentration parallel to changes in the gene expression of lipogenic- and lipolytic-related genes in adipose tissue of dairy cows around parturition. Subcutaneous fat biopsies were taken from 27 dairy cows in week 8 antepartum (a.p.), on day 1 postpartum (p.p.) and in week 5 p.p. Blood samples were assayed for concentrations of leptin and non-esterified fatty acids (NEFA). Subcutaneous adipose tissue was analysed for mRNA abundance by real-time qRT-PCR encoding for leptin, adiponectin receptor 1 (AdipoR1), adiponectin receptor 2 (AdipoR2), hormones-sensitive lipase (HSL), perilipin (PLIN), lipoprotein lipase (LPL), acyl-CoA synthase long-chain family member 1 (ACSL1), acetyl-CoA carboxylase (ACC), fatty acid synthase (FASN) and glycerol-3-phosphate dehydrogenase 2 (GPD2). Body weight and body condition score of the cows were lower after parturition than before parturition. The calculated energy balance was negative in week 1 and 5 p.p., with higher negative energy balance in week 1 p.p. compared with that in week 5 p.p. On day 1 p.p., highest concentrations of NEFA (353.3 μmol/l) were detected compared with the other biopsy time-points (210.6 and 107.7 μmol/l, in week 8 a.p., and week 5 p.p. respectively). Reduced plasma concentrations of leptin during p.p. when compared with a.p. would favour increasing metabolic efficiency and energy conservation for mammary function and reconstitution of body reserves. Lower mRNA abundance of ACC and FASN expression on day 1 p.p. compared with other biopsy time-points suggests an attenuation of fatty acid synthesis in subcutaneous adipose tissue shortly after parturition. Gene expression of AdipoR1, AdipoR2, HSL, PLIN, LPL, ACSL1 and GPD2 was unchanged over time.     

两种日粮对乌金猪脂肪组织脂类分解代谢相关基因表达的影响

为探讨不同日粮对乌金猪不同生长阶段脂类分解代谢的差异。选用乌金猪为研究对象,以本实验室前期研究确定的乌金猪适宜能量与蛋白水平的日粮和美国NRC(1998)推荐的猪营养需要量为依据,设计和配制乌金猪WJ和NRC日粮。选取体重约23kg的乌金猪36头,公母各半,随机分为2个处理组,每个处理下设3个重复,每个重复6头。分别于30kg、60kg和100kg体重时屠宰,通过real-time PCR比较了4个脂肪分解代谢相关基因在脂肪组织中表达的差异。结果显示:在各个屠宰体重,WJ日粮组HSL基因相对表达量均高于NRC日粮组(P>0.05);在各个屠宰体重,WJ日粮组LPL基因相对表达量均显著高于NRC日粮组(P<0.05);在30kg和60kg屠宰体重,WJ日粮组CPT-1基因的相对表达量显著高于NRC日粮组(P<0.05),但在100kg屠宰体重水平时,WJ日粮组CPT-1基因的相对表达量低于NRC日粮组(P>0.05);在各个屠宰体重,WJ日粮组PPARγ基因的相对表达量均高于NRC日粮组,在30kg屠宰体重达到显著水平(P<0.05)。结果提示:WJ日粮通过上调脂肪分解代谢相关基因的表达促进了脂肪组织脂肪的分解,减少了脂肪沉积。     

饲养方式对滩羊羔羊肌肉及脂肪组织中脂肪酸组成的影响

为探究饲养方式对滩羊羔羊肌肉和脂肪组织中脂肪酸组成的影响,试验选择24只健康且体重相近（14.16 kg±0.58 kg）的2月龄滩羊羔羊随机分成舍饲组和放牧组,每组12只,于4月龄屠宰取其背最长肌、股二头肌、膈肌、皮下脂肪、肾周脂肪、尾部脂肪,用气相色谱仪测定脂肪酸含量。结果表明：①在肌肉组织饱和脂肪酸中,与放牧组相比,舍饲组滩羊羔羊股二头肌丁酸、棕榈酸含量显著提高（P<0.05）,膈肌辛酸、月桂酸、肉豆蔻酸含量显著降低（P<0.05）。在肌肉组织不饱和脂肪酸中,与放牧组比较,舍饲组滩羊羔羊背最长肌棕榈油酸、花生四烯酸含量显著降低（P<0.05）,γ-亚麻酸、α-亚麻酸含量显著提高（P<0.05）,二十碳五烯酸（EPA）、n-3多不饱和脂肪酸（n-3 PUFA）极显著提高（P<0.01）;股二头肌花生四烯酸含量显著降低（P<0.05）,十七碳一烯酸、α-亚麻酸、EPA、n-3 PUFA含量极显著提高（P<0.01）;膈肌棕榈油酸含量显著降低（P<0.05）。②在脂肪组织饱和脂肪酸中,与放牧组比较,舍饲滩羊羔羊皮下脂肪十一碳酸、十五碳酸含量显著降低（P<0.05）,十三碳酸含量极显著降低（P<0.01）;肾周脂肪葵酸、肉豆蔻酸含量显著降低（P<0.05）,丁酸、硬脂酸含量极显著提高（P<0.01）;尾脂十一碳酸含量显著降低（P<0.05）。在脂肪组织不饱和脂肪酸中,与放牧组比较,舍饲滩羊羔羊皮下脂肪十八碳二烯酸含量极显著提高（P<0.01）,肉豆蔻油酸、棕榈油酸、γ-亚麻酸含量极显著降低（P<0.01）;肾周脂肪十八碳一烯酸、α-亚麻酸、n-3PUFA含量显著提高（P<0.05）,肉豆蔻油酸含量显著降低（P<0.05）,十七碳一烯酸、二十碳二烯酸、十八碳二烯酸含量极显著提高（P<0.01）;尾脂肉豆蔻油酸、棕榈油酸含量显著降低（P<0.05）,十八碳二烯酸含量极显著提高（P<0.01）。综上,不同饲养方式对滩羊羔羊肌肉和脂肪组织脂肪酸含量存在一定影响,舍饲滩羊羔羊股二头肌中饱和脂肪酸含量及肾周脂肪中不饱和脂肪酸含量显著高于放牧滩羊羔羊。     

Expression of plasminogen activator-related genes in the adipose tissue of lactating dairy sheep in the early post-weaning period

There is growing evidence that plasminogen activator inhibitor type 1 (PAI-1) is expressed in adipose tissue and its expression is implicated in inflammation that accompanies obesity-associated diseases. The physiological role of other genes implicated in the plasminogen-activating cascade such as urokinase-type plasminogen activator (u-PA), u-PA receptor (u-PAR) and plasminogen activator inhibitor type 2 (PAI-2) in ovine adipose tissue remains unknown. The objective of this study was to examine the changes in the expression of four plasminogen activator (PA)-related genes during the early post-weaning period in dairy ewes. A total of 21 subcutaneous adipose tissue samples were obtained from seven lactating dairy ewes of the Chios breed at weeks 1, 2 and 4 after weaning. Results indicated that expression of all PA-related genes was detected in most of the samples examined. Greatest expression of u-PAR corresponded to highest (week 1), while greatest expression of PAI-2 corresponded to lowest (week 4) rate of lipolysis, as indicated by the expression of hormone-sensitive lipase, in the ovine adipose tissue. There were no significant differences in the expression of the other two PA-related genes (u-PA, PAI-1) throughout the experimental period. Plasminogen activator-related genes are not expressed in a coordinated manner in the adipose tissue of lactating dairy sheep in the early post-weaning period. In conclusion, adipose tissue mobilization is correlated with highest expression of u-PAR and lowest expression of PAI-2.     

Relationship between the Amount of Linoleic Acid in the Diet and That in the Adipose Tissue of Adult Cats Living Freely in Households

The present study was carried out to ascertain whether linoleic acid intake and the content of this fatty acid in adipose tissue are correlated in cats. The linoleic acid intake, as estimated from a food intake questionnaire, was indeed correlated with the linoleic acid content of the abdominal body fat in 165 adult, female cats. A statistically significant linear correlation coefficient of 0.43 was found between the percentage of linoleic acid in the adipose tissue and that in the diet. It is plausible that the observed acid content of adipose tissue of free-living cats may be considered to be a valid biomarker of linoleic acid intake that might be used in studies on diet and chronic disease.     

The effect of various anionic salts on ruminal pH and short-chain fatty acids in non-pregnant and non-lactating cows

AIM: To evaluate whether the different anionic salts used in the prevention of parturient paresis have an impact on the ruminal pH and the production of short-chain fatty acids (SCFA) in mature non-pregnant, non-lactating cows.

METHODS: Eleven Holstein-Friesian crossbred cows were administered 2,000 mEq of either one of three chloride salts, viz CaCl₂, MgCl₂, or NH₄Cl; four sulphate salts, viz CaSO₄, CaSO₄ with a grain size of 10 µm, MgSO₄, or (NH₄)₂SO₄; two combinations of anionic salts, viz CaCl₂+MgSO₄, or CaSO₄+NH₄Cl; NaCl; or water, via a ruminal cannula over a 14-day treatment period. The salts and controls were assigned in an 11 × 11 Latin square, and the cows were distributed randomly. Ruminal fluid was collected four times in each treatment period for monitoring the ruminal pH, and four times a day at Days 7 and 14 for monitoring any changes in the concentrations of SCFA.

RESULTS: Feeding anionic salts did not change the ruminal pH, total concentration of SCFA, or distribution pattern of the main SCFA acetic acid, propionic acid, butyric acid or valeric acid (p>0.05).

CONCLUSIONS AND CLINICAL RELEVANCE: Feeding anionic salts has no negative side effect on the ruminal pH and concentrations of SCFA in mature non-pregnant, non-lactating cattle. Impaired function of the rumen due to the feeding of anionic salts is not likely.     

The effect of concentrate feeding on calcium metabolism and plasma gastrin concentration in parturient cows

The effect of concentrate feeding on calcium metabolism was studied in pregnant cows. The concentrate (5 kg/day) was added to the diet about three weeks before expected calving. A control group was fed only hay during the whole dry period. It was earlier observed in sheep that concentrate feeding was followed by a disturbance in calcium homeostasis, but no such disturbances were observed in the cows. The concentrate fed cows consumed 50 % more calcium than the controls and were found to mobilize less calcium from the skeleton immediately after calving. There was no evidence for the theory that the gastro-intestinal hormone gastrin is involved in calcium homeostasis in the parturient cow.     

沙葱及其提取物对舍饲肉羊肾周脂肪膻味物质代谢组特征的影响

本试验旨在探究不同膻味水平舍饲肉羊肾周脂肪代谢组学特征。试验分为4组,每组15只小尾寒羊羔羊,其中各试验组分别饲喂沙葱粉（AMR）、沙葱水提物（AWE）及沙葱醇提物（AFE）,对照组（CK）饲喂基础饲粮。试验结束后从各组中随机选择6只羊屠宰,采集背部皮下脂肪、尾部脂肪、肾周脂肪和大网膜脂肪样品,检测4-烷基支链脂肪酸（BCFA）的沉积量,并以此为依据筛选极高膻味水平样品和极低膻味水平样品。采用LC-MS的方法,探究不同膻味水平舍饲肉羊肾周脂肪代谢组学特征。结果表明：沙葱及其提取物能够改善除尾部脂肪外其它部位脂肪组织中（肾周脂肪、背部皮下脂肪和大网膜脂肪）3种支链脂肪酸,且肾周脂肪最为敏感,其中沙葱醇提物对降低肾周脂肪中3种支链脂肪酸的沉积量效果最佳（MOA P<0.001;MNA P=0.044;EOA P<0.001）。代谢组学研究发现,组氨酸代谢通路、甘油磷脂代谢通路、精氨酸和脯氨酸代谢通路及亚油酸代谢通路及其相关代谢产物可能与膻味相关物质的合成有关。综上所述,沙葱醇提物可能通过影响舍饲肉羊机体脂肪酸及氨基酸代谢通路,调控相关代谢产物的合成,进而影响4-烷基支链脂肪酸的合成,从而改善羊肉膻味。     

Lipid mobilization and inflammatory responses during the transition period of dairy cows

The transition period of dairy cattle is characterized by dramatic changes in metabolism and host defense mechanisms that are associated with increased disease. Intense lipid mobilization from tissue stores is an important metabolic adaptation during the transition period that results in significant release of non-esterified fatty acids (NEFA) into the blood stream. Whereas these fatty acids are important sources of energy during times of increased metabolic demands, elevated concentrations of NEFA are known to disrupt several immune and inflammatory functions. This review will discuss the implications of lipid mobilization on inflammatory responses with special emphasis on leukocytes and endothelial cell functions during the transition period of dairy cows.     

Decrease in stearic acid proportions in adipose tissues and liver lipids in fatty liver of dairy cows

Samples of liver and perirenal, mesenteric and subcutaneous fat were collected from 16 sick necropsied dairy cows to evaluate the fatty acid profiles in the hepatic and adipose tissues associated with advanced fatty liver or hepatic lipidosis. Hepatic triglyceride and eight fatty acids were measured in the hepatic and adipose tissues. Six cows had more than 3% triglyceride on fresh weight in their livers and were classified as having fatty liver. Stearic and linoleic acid proportions in the liver decreased markedly with increased hepatic triglyceride levels, while the proportion of palmitic and oleic acids increased. The most striking fluctuations in hepatic lipidosis were manifested as decreased stearic acid in the adipose tissues including subcutaneous fat with the trend of decreasing stearic acid. Palmitic acid was elevated in hepatic and perirenal fat in fatty liver cows. In instances of advanced hepatic lipidosis, palmitoleic acid increased in only subcutaneous fat and not in perirenal or mesenteric fat. In addition to the proportions of hepatic fatty acids in fatty liver, this study also clarified the fluctuations observed in the profiles of fatty acids of the adipose tissues in cows with advanced hepatic lipidosis, particularly the decline in the proportions of stearic acid.     

脂联素的生理作用及其在养猪中的应用前景

脂联素是脂肪组织特异性分泌的一种脂肪细胞因子,具有调控生物体的能量稳态、葡萄糖代谢和脂肪代谢等功能。它通过降低脂肪沉积的效应、减重效应及对胰岛素的增敏效应调控能量分配;此外,还具有抗炎、抗血管损伤功能,可能为治疗相关的动物疾病提供新的靶点。本文介绍了脂联素的来源、分子结构、生物学功能及影响其分泌的因素,阐述了脂联素对动物脂肪沉积的影响及其在脂肪-骨骼肌信号通路中的作用,展望了脂联素在养猪生产中的应用前景。     

Plasma lipids in normal cows around partus and in cows with metabolic disorders with and without fatty liver

Free fatty acids, cholesterol and phospholipids in plasma were studied from 6 weeks before to 6 weeks after calving in 16 normal multiparous cows. The same plasma lipids were studied the day after calving in 20 normal primiparous cows. Ten of these were fed according to standards and the other 10 were overfed the last 3 weeks prepartum. The plasma lipids were also analysed in 16 cows with left displacement of the abomasum and fatty liver, and in 16 cows with ketosis with no or only slight fat infiltration of the liver. In the normal cows there was a rise in FFA-level and a reduction in cholesterol and phospholipids from 6 weeks before to the day after calving. Thereafter there was a reduction of FFA-level and rise in cholesterol and phospholipids. Increased feed intensity had no effect on plasma lipids at calving. The level of the plasma lipids in cows with fatty liver differed very much from the amounts in normal cows at corresponding time from calving. Cows with ketosis had high FFA-level but the amount of cholesterol and phospholipids differed very little from normal cows.     

Comparison of the Labour Requirement Involved in the Housing of Dairy Cows in Different Housing Systems

Dairy cows are in Denmark either kept in tie-stalls or in loose housing systems. The labour requirement connected to the two systems is very important for dairy farmers who want to adopt a new housing system. The aim of the present investigation was to estimate the labour requirement for the various tasks involved in milk production in different housing systems. The estimation was done by use of models, which were based on detailed work studies carried out among 13 practical stockbreeders. The efficiency of the different housing systems depended on the size of herd. For herd sizes over 100 cows, the total labour requirement was between 27 and 31% lower in loose housing systems than in tie-stall housing systems. However, when the herd sizes were reduced to fewer than 70 dairy cows, the savings obtained on the tasks feeding and cleaning in loose housing systems were counterbalanced by a higher labour requirement on milking.     

Fatty acid profile of plasma,muscle and adipose tissues in Chilota lambs grazing on two different low quality pasture types in Chiloé Archipelago (Chile)

There is no information about the effect of different pasture types on tissue fatty acid profiles of a native rustic lamb breed of the Chiloe Archipelago, the Chilota. Eight Chilota lambs were grazed on a ‘Calafatal’ pasture (CP), a typical secondary succession of Chiloé Archipelago (Chile) and eight Chilota lambs were located to graze on naturalized pasture (NP) of Chiloé. Botanical, chemical and lipid composition of the two types of pastures and of different lamb tissues (muscle, subcutaneous – and tail adipose tissues) and plasma were performed. Both pasture types induced high n‐3 polyunsaturated fatty acids (PUFA) and CLAcis‐9,trans‐11 proportions in Chilota meat. Thus, in muscle, Chilota lambs grazing CP showed higher sum PUFA, sum n‐6 PUFA proportion and n‐6/n‐3 PUFA ratio compared with Chilota lambs grazing NP. In tail fats of Chilota lambs grazing CP significantly higher proportions of 18:3n‐3, sum saturated fatty acids, sum PUFA, n‐3 and n‐6 PUFA were detected compared with Chilota lambs grazing NP. Feeding of different pasture types (CP vs. NP) caused significant differences in fatty acid composition of muscle and the two fat depots in Chilota lambs, but also point to tissue‐specific responses of de novo synthesized fatty acid deposition in the tissues.     

Physiological changes during feeding and rumination in cows

In this study, we investigated the physiological changes in cattle during feeding and rumination. We collected blood samples every 5 min by using an automated blood sampling system and simultaneously recorded feeding, ruminating, and other behaviors using a video camera. Plasma non‐esterified fatty acid (NEFA) concentrations continuously decreased during feeding and decreased temporarily during rumination. Plasma glucose concentration continuously decreased during feeding and remained stable during rumination. During feeding and rumination, there were no characteristic increases and subsequent decreases in plasma insulin and growth hormone (GH) concentrations, although insulin concentrations were positively correlated with glucose concentration. NEFA concentrations were not correlated with GH and insulin concentrations. In terms of chewing behavior, feeding and rumination are similar; therefore, the changes in metabolites such as NEFA might have been the same. Combination of behavioral observations and application of an automated blood sampling system could contribute to new findings on behavioral and physiological changes regarding the temporary decrease in plasma NEFA concentration during rumination in ruminants.     

不同胎次和产奶量的奶牛鲜奶脂肪酸含量比较

用气相色谱测定了不同胎次及不同产奶量奶牛鲜奶的脂肪酸含量。一胎４２个、二胎４８个、三胎２０个鲜奶样品。２０００～３０００千克１５个、３００１～４０００千克４１个、４００１～５０００千克３５个、５００１～６０００千克７个鲜奶样品。结果发现，１８：１脂肪酸含量为３３．４８％～３４．８６％；１８：２为８．５１％～１０．０８％；１４：０为７．９４％～１０．１４％；１６：０为２４．０４％～２６．２４％；１８     

Effect of extruded linseed on productive and reproductive performance of lactating dairy cows

A total of 356 early lactation multiparous Holstein cows were used in a randomized complete block design to determine the effects of feeding extruded linseed on milk production and composition, and reproductive performance. Forty of these cows were randomly selected to study the effects of extruded linseed on milk fatty acid (FA) profile, individual feed intake and prostaglandin secretion. Cows were fed a 40:60 forage to concentrate ratio diet (17.9% CP, 27.7% NDF and 6.0% EE) ad libitum that was similar in composition between treatments except for the protein supplements that differed and were control (CTR: 4.9% extruded soybean) and linseed (LIN: 5.5% extruded linseed). Individual DM intake measured at 40 (23.0 kg/d) and 90 (24.2 kg/d) days in milk, and milk yield (45.0 kg/d) were not affected by treatment, but the lower (P < 0.05) milk fat percentage in cows fed LIN (2.65%) compared with CTR (2.86%) resulted in lower (P < 0.05) 4.0% fat-corrected milk yield for cows fed LIN (35.4 kg/d) compared with CTR (37.7 kg/d). Milk protein content was higher (P < 0.05) in LIN (3.04%) than in CTR (3.00%). The concentration of saturated FA was lower (P < 0.05) in milk fat from LIN (56.2%) compared with CTR (60.2%). Monounsaturated FA (35.7 vs. 32.7%) and polyunsaturated FA (8.0 vs. 6.9%) were higher in LIN (P < 0.05) than in CTR. Supplementation with LIN also increased (P < 0.05) the proportion of vaccenic acid (2.21 vs. 1.55%), total conjugated linoleic acid (0.91 vs. 0.72%) and n-3 FA (1.21 vs. 0.54%) in milk compared with CTR. Plasma concentrations of prostaglandin metabolite were numerically lower in LIN (106 pg/ml) compared with CTR (120 pg/ml) (P = 0.16) but reproductive performance was similar between treatments. In summary, extruded linseed reduced milk fat percentage and 4.0% fat-corrected milk yield and increased milk protein percentage and the content of healthy FA in milk without modifying DM intake, milk yield and reproductive performance.     

饲粮过瘤胃胆碱添加量对泌乳早期奶牛生产性能及血液指标的影响

本试验旨在研究饲粮过瘤胃胆碱添加量对泌乳早期奶牛生产性能及血液指标的影响.试验选用4头胎次、预产期、体重、产奶量相近的健康荷斯坦牛,采用4×4拉丁方试验设计,试验处理为每头牛的饲粮中每天添加0、30、60或90 g过瘤胃胆碱(氯化胆碱含量分别为0、7.5、15.0、22.5 g).试验共分为4期,每期15 d.试验结果...