The effects of diet,slaughter weight and docking on growth,carcass composition and meat quality of fat-tailed Barbarine lambs. A review

This review summarises the main factors that influence meat production and quality in fat-tailed Barbarine (FTB) lambs. As a general feature, FTB lamb's growth is moderate, and the average daily gain ranges between 100 and 350 g. The carcass being relatively fatty, carcass fat content varies from 10% to 32%; white fat and rose meat are often dominant in these carcasses. The meat fatty acid profile of this fat-tailed breed is similar to that of thin-tailed ones, with a prevalence of palmitic, stearic and oleic acids. The order of dissected adipose tissues accumulation, estimated by allometry coefficients, is in agreement with observations in thin-tailed sheep. However, tail fat allometry coefficient is closer to kidney fat values rather than to the subcutaneous one. Concerning effects of feed level, growth of FTB lambs fed silage is higher than those fed oat hay. With moderate concentrate supply, FTB lambs' growth is more pronounced on pasture diet than on the feedlot (FL) diet. Furthermore, at similar slaughter weights, carcasses of lambs fed pasture diet have less tail and carcass fat than those from lambs fed FL diet (5% and 18% vs. 9% and 24% for grazing and FL lambs, respectively). No difference in fat colour, fat firmness or cooked meat flavour is observed between carcasses obtained at different slaughtering weight (i.e. from 25 to 35 kg). The tail docking of FTB improved lambs' growth particularly before weaning. Its effect on carcass composition and fat proportion depends on stage of slaughtering and type of fattening diet. For suckled lambs (4 months), the docking resulted in the lower carcass fat weight (and proportion), while for fattened lambs, carcass composition was similar for all types of lambs. Overall, FTB lambs always grow slower than Noire de Thibar lambs. This is particularly pronounced during the fattening phase. Then, for FTB breed, the possibilities to obtain heavy carcasses are at risks of fat accumulation, 22.8% vs. 14.4% for FTB and Noire de Thibar thin-tailed lambs, respectively. However, the main advantage of FTB breed is that adults are well adapted to food scarcity and may produce lambs even under harsh conditions.     

Breeding objectives for the Boran breed in Kenya: Model development and application to pasture-based production systems

Bio‐economic profit models were developed and applied to evaluate biological and economic variables that characterize production systems utilizing the Boran breed. Production systems were described according to their sale age (24 months short‐fed or 36 months long‐fed), levels of input (low, medium or high) and final goal (beef or dual purpose) representing practical circumstances that exist in the various beef cattle farms in Kenya. The input variables were classified into production and economic variables. The outputs from the profit models included revenue, costs and feed intake of cows, heifers and steers in the different production systems. These models can be used to simulate changes in production and marketing circumstances. The biological relationships and assumptions in the model are general and flexible and can therefore be applied to a wide range of beef cattle production circumstances by changing the input variables. In addition, by modifying the herd dynamics and management variables this model may be applied in Kenya or other countries to production systems that utilize indigenous cattle genetic resources or their crosses with Bos taurus breeds.     

Dietary sources and their effects on animal production and environmental sustainability

Animal agriculture has been an important component in the integrated farming systems in developing countries. It serves in a paramount diversified role in producing animal protein food, draft power, farm manure as well as ensuring social status-quo and enriching livelihood. Ruminants are importantly contributable to the well-being and the livelihood of the global population. Ruminant production systems can vary from subsistence to intensive type of farming depending on locality, resource availability,infrastructure accessibility, food demand and market potentials. The growing demand for sustainable animal production is compelling to researchers exploring the potential approaches to reduce greenhouse gases(GHG) emissions from livestock. Global warming has been an issue of concern and importance for all especially those engaged in animal agriculture. Methane(CH_4) is one of the major GHG accounted for at least 14% of the total GHG with a global warming potential 25-fold of carbon dioxide and a 12-year atmospheric lifetime. Agricultural sector has a contribution of 50 to 60% methane emission and ruminants are the major source of methane contribution(15 to 33%). Methane emission by enteric fermentation of ruminants represents a loss of energy intake(5 to 15% of total) and is produced by methanogens(archae) as a result of fermentation end-products. Ruminants' digestive fermentation results in fermentation end-products of volatile fatty acids(VFA), microbial protein and methane production in the rumen. Rumen microorganisms including bacteria, protozoa and fungal zoospores are closely associated with the rumen fermentation efficiency. Besides using feed formulation and feeding management, local feed resources have been used as alternative feed additives for manipulation of rumen ecology with promising results for replacement in ruminant feeding. Those potential feed additive practices are as follows: 1) the use of plant extracts or plants containing secondary compounds(e.g., condensed tannins and saponins) such as mangosteen peel powder, rain tree pod; 2) plants rich in minerals, e.g., banana flower powder; and 3) plant essential oils, e.g., garlic, eucalyptus leaf powder, etc. Implementation of the-feed-system using cash crop and leguminous shrubs or fodder trees are of promising results.     

Physiological response of crossbred sheep under nutritional scarcity

Nutritional scarcity during summer and winter is a major constraint for sheep rearing in the semi-arid tropical region. In this region, a new crossbred sheep has been developed by the crossing of a native sheep breed Malpura with a breed of hot-humid coastal region breed Garole. A study was conducted for 9 weeks to assess the physiological response of crossbred (Garole x Malpura x Malpura, GMM) rams under nutritional scarcity in the semi-arid tropical region. Eighteen adult crossbred rams were randomly allocated into three groups of six animals each. The groups are G1 (control, ad libitum feeding), G2 (20% less than ad libitum feeding), and G3 (30% less than ad libitum feeding). The animals were stall-fed with a diet consisting of 70% roughage (Cenchrus ciliaris hay) and 30% concentrate feed. Body weight gain, average daily gain, and feed intake were significantly (P?<?0.05) lower in G2 and G3 as compared to G1 rams. Water intake was significantly (P?<?0.05) higher in G2 and G3. Physiological responses, blood biochemical and endocrine profile did not differ between the groups. The results indicate that the crossbred rams evolved through the crossing of the hot semi-arid tropical region breed with hot humid coastal region breed are able to maintain their body homeostasis despite nutritional scarcity although their body weight decreased.

     

景泰当地羊品种改良

在考虑景泰当地气候及资源的基础上提出以无角陶赛特、萨福克、特克赛尔为终端父本,与本地寒滩组成三个杂交组合的平均初生重、繁殖成活率、1月龄、3月龄、6月龄、9月龄、周岁体重优于当地品种二元杂交羊,经济效益显著。发挥了当地滩羊耐粗饲、适宜当地环境的特点,四季发情,改进了二元杂交羔羊体躯不丰满、个体产肉量低的缺陷。试验认为,各组合三元杂交羔羊育肥至6月龄出栏最佳。     

Evaluation of the efficiency of alternative two-tier nucleus breeding systems designed to improve meat sheep in Kenya

A deterministic approach was used to genetically and economically evaluate the efficiency of five two‐tier nucleus breeding systems for meat sheep in Kenya. The nucleus breeding systems differed in terms of whether the system was closed or open, in the type of animals that were involved in the movement of genetic superiority and in the number of selection pathways in each system. These systems were compared under four alternative breeding objectives based on monetary genetic gain and profit per ewe. The first objective simulated a situation where the flock size cannot be increased due to non‐feed related constraints (FLOCK). The second specifically assumed that the flock size is restricted due to limited amount of feed resources (FEED). The third and fourth objectives assumed that sheep performed only tangible roles (TR) and both tangible and intangible roles (IR) in the production system respectively. Monetary genetic gains were highest for all objectives in an open nucleus system with a certain proportion of commercial‐born ewes being introduced in the nucleus while at the same time utilizing young rams from the nucleus to breed sires and dams for the nucleus and commercial sector (ONyre). Utilizing young rams in a closed nucleus system for the dissemination of superior genes resulted in higher annual monetary genetic gain than utilization of old rams. Profit per ewe was significantly higher for FLOCK and IR in ONyre. In a closed system that allowed for downward movement of dams from the nucleus to the commercial sector to breed sires and dams, profit per ewe was highest for FEED and TR. The success of a nucleus breeding system should also focus on the profitability and logistics of establishing it. The implication of these results on the choice of two‐tier nucleus breeding systems for the improvement of meat sheep is discussed.     

Performance and limitation of two dairy production systems in the North western Ethiopian highlands

In order to characterise the dairy production systems as well as the productive and reproductive performance of dairy cows in the study area, a total of 256 and 54 dairy farms were used for survey and monitoring data collection, respectively. Based on breed, land size, feed and market accessibility, two major dairy production systems were identified: a rather specialized, urban, and a peri-urban dairy production system. Urban farmers owned larger herds but farmed less land, and sold a greater proportion of liquid milk than peri-urban farmers, who processed more milk. Purchased feed played a more important role for the feed supply of urban than peri-urban farms. Significant breed effects were found for productive and reproductive performance traits. It is concluded that improved breeding and health management, genetic improvement of local breeds and supplementation of poor quality feed resources are the key factors for enhancing productivity of dairy cows and thereby increasing family income from milk production.     

绵、山羊生产科技支撑现状与未来需求技术研究分析

发展绵、山羊生产是畜牧业生产结构调整的重点环节，是节粮型畜牧业发展的主要方向之一，有很大的发展潜力。作者简要介绍了中国养羊生产中主要的绵、山羊品种资源、选育技术和饲养方式等科技支撑现状，并对目前养羊生产的限制因素作了简要分析，阐述了今后绵、山羊生产的进一步发展对育种、繁殖、饲料加工与调制、疫病防治等技术的需求。     

Optimizing the use of breed types in developing country livestock production systems: a neglected research area

Developing country livestock production systems are diverse and dynamic, and include those where existing indigenous breeds are currently optimal and likely to remain so, those where non‐indigenous breed types are already in common use, and systems that are changing, such as by intensification, where the introduction of new breed types represents significant opportunities. These include opportunities to improve the livelihood of the world's poor, increase food and nutrition security and enhance environmental sustainability. At present, very little research has focused on this issue, such that significant knowledge gaps in relation to breed‐change interventions remain. The purpose of this study is to raise awareness of this issue and suggests strategic research areas to begin filling these knowledge gaps. Such strategic research would include (i) assessing the impact of differing breed types in developing country livestock productions systems, from a range of viewpoints including intrahousehold livelihood benefit, food and nutrition security at different scales, and environmental sustainability; (ii) identification of specific livestock production systems within developing countries, and the type of livestock keepers within these system, that are most likely to benefit from new breed types; and (iii) identification of new breed types as candidates for in‐situ testing within these systems, such as through the use of spatial analysis to identify similar production environments combined with community acceptance studies. Results of these studies would primarily assist stakeholders in agriculture, including both policy makers and livestock keepers, to make informed decisions on the potential use of new breed types.     

Evaluation of biological and economic efficiency of smallholder pig production systems in North Vietnam

This study evaluates smallholder pig production systems in North Vietnam, comparing a semi-intensive system near a town with good market access, where a Vietnamese improved breed has replaced the indigenous pig breed, and an extensive system away from town, where the indigenous breed still prevails. Fieldwork was conducted in 64 households in four villages. Repeated farm visits yielded 234 structured interviews. Data were analysed by linear models and non-parametric tests. Production inputs and outputs were quantified, and feed use efficiency and economic efficiency were assessed. The gross margin was higher for semi-intensive production with the improved breed, while the benefit–cost ratio was higher under extensive conditions with the indigenous breed. The net benefit did not differ between systems. Twenty-four per cent of farmers yielded a negative net benefit. In one village under extensive conditions, live weight output from indigenous sows with crossbred offspring compared positively with the output from semi-intensive production with improved genotypes, but was associated with high inputs, making production inefficient. Results indicate that improved genotypes might not be an efficient production alternative for saving-oriented production with limited resource supply. Suitability of evaluation parameters, farmers’ production aims, and factors impacting the production success in different systems are discussed.     

Sheep rearing in Shaba (Zaire): present-day situation

Four sheep rearing systems have been studied in Shaba (Zaire) to compare production and profit levels. Weight production per mother at nine months of age is 4.5 kg under traditional breeding conditions, versus 23 kg in the ranching system (with shepherd) and 30 kg under extensive rearing. Management of range by fire and rotation and feeding habits, principally explain variations in the production. Internal parasite control and housing conditions are next important. Extensive sheep breeding under the ranching system, succeeding to cattle on pasture, appears to be the most profitable rearing system in the region.     

Indigenous sheep breeds of North Ethiopia: characterization of their phenotype and major production system

A study was conducted in Tigrai, Northern Ethiopia to describe the sheep breeds and their production system. The survey was done in selected districts known for their high sheep population density. The phenotype characterization identified distinct features for each breed. The breeds are Aberegelle, Ille, Begait, and the common Tigrai highland sheep. The strong discriminating phenotypes are face profile, tail type, and compactness; accounting for 83.48, 17.95, and 2.93 % respectively of the total variability among breeds. The flock structure are affected by the market demand; requirements of breeding females and feed availability. Farmers tend to keep more female sheep for longer (culling age of 5.9?±?0.4 and 1.9?±?0.5 for females and males, respectively) for the reasons of feed shortage and need to maximize number of breeding female. The ratio of male to overall female is large (1:6) and thus a single ram gets maximum contact time with ewes and ewe lambs. The overall average age at puberty for females is 9–14 months. However, the presence of very young lamb rams and uncontrolled mating system lead to early breeding of females which results in low conception rate, low birth weight, poor survival rates, and in extreme cases causing inbreeding. It was also possible to identify the critical control points such as breed, age of animals, nutrition, and feeding systems affecting the provision of live animals for good meat quality.     

Mini review: breeding Awassi and Assaf sheep for diverse management conditions

The Local Awassi, a triple-purpose breed for meat, milk, and carpet–wool production, is a low-prolific, hardy breed that is well adapted to the unfavorable conditions of the Middle East, where it is managed under traditionally extensive to semi-extensive conditions. Breeding work with the Awassi has included within-breed selection, crossbreeding, and gene introgression. Those efforts resulted in a variety of Awassi-derived genotypes that successfully occupy semi-intensive as well as intensive production systems. Thus, within-breed selection resulted in development of the “Improved Awassi”—a dairy-type Awassi strain which, under intensive management, produces over 500 l milk/ewe annually; crossbreeding with the East Friesian breed led to the development of the Assaf dairy breed, which exceeds the Improved Awassi in prolificacy and in year-round breeding activity, and introgression of the B allele of the FecB locus into the Awassi and Assaf breeds resulted in the formation of the prolific Afec Awassi and Afec Assaf strains, with prolificacies of 1.9 and 2.5 lambs born per ewe lambing, respectively. Advanced molecular genetics tools have enabled a better understanding of how the Awassi breed was formed during domestication and have uncovered differences in its genetic structure compared to other breeds. Implementing large-scale selection schemes that implement emerging new information on the sheep genome, overcoming threats of inbreeding depression, and further breeding for high uterine capacity are the new breeding goals for the Awassi, Assaf, and their derivatives.     

肥东县奶牛养殖现状及发展对策

根据肥东县奶牛养殖的调查结果,针对当前奶牛生产在奶价偏低、养殖效益低下、中小养殖场户高产奶牛少、饲养管理水平不高、基础设施不完备、卫生防疫制度不健全等方面存在的问题,结合我县奶牛养殖现状和发展奶牛生产的优势,提出了加快品种改良,实施标准化生产,广开饲料饲草资源,抓好社会化服务,加强疫病防治,加大投入力度等对策。     

舍饲因素对妊娠后期繁殖母羊生产性能影响研究

本项研究的目标是通过试验分析,找出舍饲条件中对繁殖母羊生产性能起主导作用的影响因素,并探索应对措施以指导生产。为此,笔者于2009年末开始在洮南市向阳乡开展了舍饲对母羊生产性能影响要素研究试验。结合我省西部的气候和饲料资源条件,总结试验结果,我们推荐在生产中使用代谢能8.50MJ/kg、粗蛋白9.50%、环境温度＋4℃、饲养密度0.8只/m2、环境湿度60%的参数,对妊娠后期繁殖母羊有较好的增产效果。     

Comparative aspects of plant tannins on digestive physiology,nutrition and microbial community changes in sheep and goats: A review

Comparative aspects of plant tannins on digestive physiology, nutrition and microbial community in sheep and goats are discussed in the context of differences due to feed intake, digestibility, utilization of nutrients and microbial community. The purpose of this review was to present an overview of the potential benefits of tannin‐containing diets for sheep and goats and specie differences in their response to tannins. It is well established that moderate level of tannins in the diet (3%–4% tannins DM) can precipitate with soluble proteins and increase protein supply to the sheep, but comparative aspects of tannin‐containing diets in sheep and goats on animal performance, digestive physiology, rumen microbial changes and potential benefits to sustainable animal production by those compounds have received little attention. In addition, developing plant‐based tannin‐containing diets for control of rumen microbiota and rumen fermentation (e.g., methane gas) would be expected to have a greater impact on the ruminant health, productivity and emission of greenhouse gasses. The positive impacts of the plant tannin compounds mainly depend on their influence on the gut microbiome diversity and ability to generate fermentation end products (short‐chain fatty acids) that have diverse biological roles. Diets which contain optimal levels of tannins have potential benefits for sustainability of small ruminant production systems. However, there is a need for an improved understanding of the utilization of tannin‐containing forages to improve their management. This implies investigations of animal responses to tannin‐containing forages or browse species and, in particular, a better understanding of the interactions that can arise between sheep and goats on digestion, DMD, rumen fermentation and microbial community changes. This knowledge could help to improve current feeding systems in terms of efficiency of feed use and environmental impacts (reduce methane gas production) and thus contribute to the development of a sustainable sheep and goat production.     

Suckler cow efficiency – breed by environment interactions in commercial herds under various natural production conditions

ABSTRACT

The significance of breed by environment interaction on suckler cow efficiency traits was investigated, using production data from the Norwegian Beef Cattle Recording System and data collected (feed regimes, etc.) from 27 commercial suckler cow herds. Two statistical approaches were used; mean breed performance in extensive/intensive environments (mixed models), or as within breed regressions of cow performance on modelled cow energy intake. Aberdeen Angus produced higher weaning weight than Hereford below 12,000?MJ NE (241?kg) and Charolais below 13,000?MJ NE (244?kg) cow energy intake in the suckler period, after which the breeds re-ranked. The corresponding re-rank between Hereford and Charolais was at 14,500?MJ NE (263?kg) cow energy intake. Overall, breed by environment interactions were observed for calving interval, number/kg calves weaned/mated cow/year and energy efficiency, which emphasise that choice of cow breed should be dependent on the natural production resources available.     

湟源地区种植青玉米试验

湟源地区是青海省绵羊实行西繁东育的基地之一,但由于饲料资源不足而限制了绵羊繁育规模,我们通过种植青玉米的试验,结果表明,青玉米产量可达到6.50kg/m2,它将为解决绵羊饲料探寻出新的途径.     

Relationships among heat production, body weight, and age in Finnsheep and Rambouillet ewes

It was the objective of this study to quantify heat production across ages of Rambouillet and Finnsheep ewes and to evaluate the previous hypothesis that breed differences can be accounted for by scaling for proportion of mature body weight. Seventy-two Finnsheep and 55 Rambouillet ewes were sampled. Heat production was estimated based on individual animal gaseous exchange, which was determined from 55 through 71 h of the feed restriction. Heat production per unit BW decreased as sheep aged, and the breed-specific functions fit the data better than the pooled functions. The rate of decrease in heat production was greater in Finnsheep ewes until 37 wk of age. The rate of growth of Rambouillet ewes was greater than that of Finnsheep ewes over the first 52 wk of age, and Rambouillet ewes reached 95% of their mature BW at an earlier age (71 wk) than did Finnsheep ewes (113 wk). At any given age, Rambouillet ewes had achieved a greater proportion of their mature BW and had a lower heat production per unit BW than Finnsheep ewes. This study demonstrated the necessity of accounting for both age and breed when estimating metabolic rate in sheep. Furthermore, this study suggested that breed and age differences in metabolic rate could be accounted for by scaling for proportion of mature BW and that daily heat production per unit BW (kcal/kg) of Finnsheep, Rambouillet, Suffolk, and Texel ewes can be described by the function /(BW, matBW) = 59.5e(-0.797(Bw/matBw)), where BW = body weight and matBW = mature body weight.     

中环肉羊新品种培育及其应用研究

本研究主要以中环肉羊新品种为例,通过了解、认识及亲自参与培育过程及应用情况研究介绍,掌握其培育方法及相关试验操作,从而提高自己在肉羊养殖中的业务水平和工作能力。结果显示,中环肉羊新品种比一般肉羊生长发育快,繁殖水平高,饲料转化率高,肉品质好,具有良好的应用推广价值。目前,中环肉羊新品种育种核心群已达到1.7万只,培育F1代1.2万只。由此可见,该品种的培育效果显著。通过加速培育进程,以此来提高培育效率。将培育、扩繁更优质的肉羊种质资源,应用推广到当地及周边的市、县,使得农户、专业合作社通过发展肉羊产业实现稳定增收,达到共同富裕的目的。