蛋氨酸羟基类似物的生产工艺及其在动物营养中的应用

蛋氨酸羟基类似物(MHA)作为蛋氨酸(Met)替代物被广泛应用于饲料添加剂中.MHA因其特殊的结构性质,不仅具备Met的营养功能,而且可以发挥Met不具备的酸化剂、抗生素等功能.随着我国畜牧和饲料添加剂行业的发展,MHA合成方法的研究及应用必将得到进一步的关注,因此,本文概述了MHA的生产工艺及其在动物营养中的应用.     

Effect of ammonium‐iron‐hexa‐cyanoferrate and of the covariates age,gender, weight,season and calendar time on radiocaesium contamination of wild boars living in the wild in Bavaria

Feed with Ammonium‐iron‐hexa‐cyanoferrate (AFCF; 1250 mg AFCF/kg) was fed between March 2009 and March 2011 to wild boars in a territory of 4.5 km² (experimental group, EXP). One hundred and forty similar territories in the same county (500 km², spruce forest, agriculture) served as control (CON). Data for comparison from all territories were available from March 2005 to March 2011. Wild boars could move between, into and from the territories. Lean skeletal muscle meat (500 g) of all wild boars that were killed by humans (hunting and traffic accidents) was investigated for gamma‐radiation from ¹³⁷Cs with a becquerel monitor with a sodium iodide scintillator crystal (range of detection 20–9999 Bq/kg). The wild boars were weighed, and gender and age were determined. For the analyses of effects, multivariable regression models were fitted with the ¹³⁷Cs concentration as response variable. There was a significant difference between the ¹³⁷Cs contamination of wild boars from CON (563 ± 932 Bq/kg meat, n = 1253) and EXP (236 ± 276 Bq/kg meat; n = 45). ¹³⁷Cs contamination decreased with increasing body weight by ?5 Bq/kg meat/kg body weight increase (p < 0.05). Females had higher Bq measurements than males (by +80 Bq/kg meat, p < 0.05). Piglets were lower than adults, but turn‐coats higher. From November to May, contamination was higher (by +500 to +600 Bq/kg meat, p < 0.05) than during the rest of the year. In 2010, contamination was higher (by +200 to + 300 Bq/kg meat, p < 0.05) in comparison with the other years under observation. When all covariates were controlled for, the effect of AFCF was highly significant. Interaction analyses showed that the intervention decreased ¹³⁷Cs contamination by ?500 Bq/kg meat during November to May and by ?200 Bq/kg meat during the rest of the year. In summary, AFCF feeding reduces ¹³⁷Cs contamination of wild boars living in the wild significantly, particularly during the season from November to May.     

Dystocia in beef heifers: A review of genetic and nutritional influences

Breeding beef heifers for the first time at 15 months of age has potential to increase the efficiency of the beef breeding-cow herd. An increased incidence of dystocia in heifers calving at 2 years of age, compared to mature cows, is a major reason many farmers in New Zealand have not adopted the practice. The predominant type of dystocia affecting 2-year-old heifers is feto-maternal disproportion, a condition in which the fetus is too large relative to the size of the heifer's pelvis. Reducing birthweight of the calf is a means of reducing the incidence of dystocia. Birthweight and length of gestation are determined by genotype of the calf, maternal genetic effects and environmental effects.

Bulls with low estimated breeding values for birthweight have been selected for mating heifers; however, the positive genetic correlation between birthweight and mature weight meant that the progeny of these bulls tended to be lighter at finishing, making them less desirable in the beef industry. The genotype of the dam also plays a role in determining the risk of dystocia; the maternal ability of the dam to nurture the fetus influences birth- weight, and the dam's genetic potential for growth influences the size of her pelvic area. Heavy heifers tend to produce high- birthweight calves, counteracting the reduction in the incidence of dystocia resulting from the larger pelvis in larger heifers.

Manipulating feeding level during pregnancy offers an alternative method for manipulating the birthweight of calves. Little is known about the effects of nutrition in early gestation on placental development or birthweight of calves. No differences in the birthweight of calves have been observed in response to variation in feeding in mid-pregnancy, and variable responses in birthweight and the incidence of dystocia to feeding in the third trimester of pregnancy have been reported. Differences in birthweight have not always resulted in differences in the incidence of dystocia, primarily due to differences in liveweight of the heifer also induced by feeding regimens. Variability in the incidence of dystocia in response to feeding level in the third trimester of pregnancy makes it difficult to make recommendations for the feeding of heifers at this stage of gestation. More research is needed into the effects of nutrition in early gestation on fetal and placental development in cattle.     

A survey of feeding,management and faecal pH of Thoroughbred racehorses in the North Island of New Zealand

AIM: To identify feeding and management variables associated with variation in faecal pH within a population of intensively managed Thoroughbred racehorses in New Zealand.

METHODS: A cross-sectional survey was conducted of 16 racehorse trainers in the North Island of New Zealand. Interviews were conducted at the trainers' stables to obtain information on feeding and management of horses, and faecal samples were collected and faecal pH measured.

RESULTS: Ninety-seven percent of the horses surveyed were confined in an area ≤5 × 5 m for ≥12 h/day. Trainer's age, number of years they had trained horses, age and gender of horses, weeks in race training, racing class, frequency of feeding, bedding type, and exercise workload had no effect on mean faecal pH. Acidic faecal pH (pH ≤6.32) was associated with stables with ≤12 horses, and trainers at stables with ≤12 horses offered more concentrate feed than those at stables with >12 horses. Acidic faecal pH was associated with trainers who offered 4 kg of grain as the only form of concentrate fed, or offered ≤2.25 kg hay/day. Horses that displayed stable vices had less acidic faecal pH than horses that did not display stable vices, viz pH 6.70 (standard error of the mean (SEM) 0.135) vs 6.43 (SEM 0.029) (p=0.04).

CONCLUSIONS AND CLINICAL RELEVANCE: Racehorse management in New Zealand is similar to that observed in other major racing countries. Trainers with ≤12 horses fed more concentrates and their horses had lower faecal pH than those of trainers with >12 horses. Irrespective of management system, it appears important to provide at least 2.25 kg of hay/day ad libitum, to buffer hindgut acidosis associated with diets high in soluble carbohydrate.     

A comparative analysis of acceptance by Japanese females and price of goat milk from different sources

A sensory survey was carried out using 4 different types of whole goat milk among middle‐class females to investigate consumer acceptability of goat milk and whether there is an opportunity to expand the sale of goat milk products in Japan. Four different types of whole milk powder (domestic concentrate‐fed, domestic pasture‐fed, USA commercially canned, and New Zealand commercially canned) were used. Fresh cow milk was served as a control. Thirty‐one housewives evaluated the 5 liquid milk samples for smell, taste and overall characteristics on a scale of 1 (low) to 3 (high). Chi‐square analyses were carried out to detect significant differences between the milk types in each category. The goat milk from the USA was the most preferred goat milk with respect to smell and overall evaluation. Domestic pasture‐fed milk received the lowest grade in the evaluation for its ‘grassy and goaty’ smell. This result shows us that pasture intake affects the taste and smell of powdered milk which gives the lowest evaluation by the participants. If Japanese goat milk producers want to be successful in the domestic goat milk market and compete against goat milk products from other countries, they should improve production methods and flavor of their products.     

Effects of increasing days of exposure to prepartum diets on the concentration of certain blood metabolites in dairy cows

Objective To evaluate the effect of the number of days exposure to a prepartum transition diet on mineral, energy and protein metabolism in dairy cows. Design A prospective cohort study. Procedures The prepartum transition diet consisted of ryegrass pasture, cereal hay, grain, grain by-product, protein meals, BioChlor®, rumen modifiers, minerals and vitamins and contained 13.9% crude protein, 10.0 MJ metabolisable energy/kg and a dietary cation anion difference of −35 meq/kg dry matter. Forty cows were bled bi-weekly from their introduction to the prepartum transition diet until day 35 of lactation. Blood samples were submitted for estimation of a range of metabolites. Cubic smoothed splines were fitted to scatterplots of metabolite concentration as a function of day relative to calving and the area under the curve (AUC) was calculated. Linear regression modelling determined the effect of days exposed, age, body condition score (BSC) and calving day on AUC. Results The prepartum AUC of blood phosphorus and beta-hydroxybutyrate increased and the AUC of blood calcium and cholesterol decreased with increasing days exposed to the diet. The postpartum AUC of beta-hydroxybutyrate and non-esterified fatty acids decreased with increasing days exposed but increased with days exposed × age and days exposed × BCS, respectively. The AUC of other metabolites did not vary significantly with number of days exposed. Conclusions Increasing exposure to the prepartum diet significantly altered the AUC of blood metabolites associated with mineral, energy and protein metabolism in ways consistent with improvements in production and reproduction previously reported and the result suggests links between energy, protein and skeletal metabolism.     

种公牛的饲养管理技术

种公牛是提高牛群质量最关健的因素,一头种公牛自然交配,与配母牛一年大约几百头。利用人工授精技术每年比本交能增加几倍。而用牛冷冻精液结合人工授精技术进行冷配每年配种母牛数量少则上万头,多则几万头。本文从饲养种公牛的基本要求出发,对种公牛的特性,营养与日常饲养管理、防疫和疾病防治,以及安全生产多方面做了整理介绍,以供同行参考。     

Endocannabinoid system and proopiomelanocortin gene expression in peripartal bovine liver in response to prepartal plane of nutrition

Endocannabinoids are fatty acid amides (FAE; oleoylethanolamide and anandamide) which have orexigenic, anorexigenic or anti‐inflammatory properties. We examined mRNA expression via qPCR of endocannabinoid receptors (CNR1 and CNR2), enzymes that synthesize FAE (HRASLS5 and N‐acyl phosphatidylethanolamine phospholipase D), enzymes that degrade FAE [fatty acid amide hydrolase (FAAH), N‐acylethanolamine acid amidase (NAAA) and monoglyceride lipase (MGLL)], and the hormone precursor proopiomelanocortin (POMC) in liver at ?14, 7, 14 and 30 days around parturition from cows fed with a control (CON; NE_L = 1.34 Mcal/kg) or moderate‐energy (OVER; NE_L = 1.62 Mcal/kg) diet during the dry period. Expression of CNR2 and POMC was greater at 7 days in cows fed with OVER because of a decrease in expression between ?14 and 7 days in cows fed with CON. Cows fed with CON had an increase in expression of FAAH, HRASLS5, NAA, MGLL and POMC between 7 and 14 days; for FAAH and HRASLS5, such response led to greater expression at 14 days vs. cows fed with OVER. Cows fed with OVER vs. CON had a approximately twofold increase in expression of MGLL between ?14 and 7 days followed by a gradual decrease through 30 days at which point expression was still greater in OVER vs. CON. FAAH, MGLL and HRASLS5 were the most abundant genes measured. Expression of the hepatic endocannabinoid system and POMC was altered by plane of dietary energy prepartum particularly during the first 2‐week postpartum. Such responses may play a role in the physiological adaptations to the onset of lactation, including energy balance and feed intake.     

饲料营养价值评定方法进展

饲料营养价值评定是动物营养研究的基本方法手段,也是建立饲料数据库,为工业饲料产品的研发和生产、畜禽养殖提供基本参数的主要手段。随着分析检验和动物试验设备装备水平的提高、试验方法的进步,饲料营养价值评定方法得到了进一步的改进。文章对饲料营养价值评定采用的新方法与传统方法进行综述。     

Relationship between a plant-based ‘vegan’ pet food and clinical manifestation of multiple nutrient deficiencies in two cats

A topical subject in human nutrition is the steadily growing number of people choosing to limit or completely avoid all animal-derived food products either for moral dilemma, health concerns or both. To meet people's will of applying their dietary choices to their domestic animals, the pet food industry answered by launching on the market some plant-based diets. This leads to concerns about whether these diets are adequately formulated to satisfy the target species nutritional requirements, especially for cats which are still considered strict carnivores. This case report follows a 2-year-old male neutered Main Coon and a 1-year-old female spayed Domestic Shorthair cat, presented to the nutrition service of the University of Toulouse, France. Reason for consultation was lethargy with in anamnesis a recent dietary transition to a plant-based pet food. Dysorexia, lethargy and muscle waste were present at first consultation. Progressive weight loss developed during follow-ups. A macrocytic, non-regenerative anaemia with serum folates below reference were the main clinical features. Analysis of pet food showed multiple nutrients below minimum recommendation at the average daily intake of both cats. Folic acid supplementation improved dysorexia, and subsequent reintroduction of animal-derived ingredients in the diet restored appetite, weight and a normal mentation in both cases.