Genetic variation of rectal temperature and its relationship to milk production in Holstein dairy cows

Milk production is significantly decreased by thermal stress. The survival and performance of an animal during heat stress periods depend on several weather factors, especially temperature and humidity. Researchers reported dramatic decreases in milk production as temperature rose above 30 degree of centigrade. Very high environmental temperature is common during the summer months in Iran. Rectal temperature is as indicator of heat tolerance and has been the most frequently used physiological variable for estimating heat tolerance in cattle. Some dairy cows are more heat tolerant and productive when subjected to heat stress. Identification and selection of heat stress resistant cattle offers the potential to increase milk yield in tropical environment. The aim of the present study was to estimate genetic parameters of heat tolerance and its relationship to milk production in Holstein Dairy Cows in Iran.

On-line application of visible and near infrared reflectance spectroscopy to predict physical and sensory characteristics of beef quality

Visible and near infrared reflectance spectroscopy (Vis-NIR) has been widely used by the industry research-base for large-scale meat quality evaluation to predict the chemical composition of meat quickly and accurately. Meat tenderness is measured by means of slow and destructive methods (e.g. Warner-Bratzler shear force). Similarly, sensory analysis, using trained panellists, requires large meat samples and is a complex, expensive and time-consuming technique. Nevertheless, these characteristics are important criteria that affect consumers’ evaluation of beef quality. Vis-NIR technique provides information about the molecular bonds (chemical constituents) and tissue ultra-structure in a scanned sample and thus can indirectly predict physical or sensory parameters of meat samples. Applications of Vis-NIR spectroscopy in an abattoir for prediction of physical and sensory characteristics have been less developed than in other fields. Therefore, the aim of this study was to test the on-line Vis-NIR spectroscopy for the prediction of beef quality characteristics such as colour, instrumental texture, water holding capacity (WHC) and sensory traits, by direct application of a fibre-optic probe to the M. longissimus thoracis with no prior sample treatment.

The effect of linkage disequilibrium on the estimates of Single Nucleotide Polymorphic effects

The identification and exploitation of single nucleotide polymorphisms (SNP) associated with production traits present new opportunities for livestock genetic improvement. Often the identified SNP is not the causative mutation but rather is in some degree of linkage disequilibrium (LD). LD markers within 5cM can be considered as direct markers for the causative mutation because they are located close to the causative mutation (Dekkers, 2004). In a dairy herd, Farnir et al., (2000) estimated that the average LD, measured as D′ was 0.5 for loci pairs positioned within 5cM. Goddard et al., (2006) estimated that LD measured as r2 decreased rapidly as the physical distance between loci increased; at a separating distance of 0.5Mb the LD (r2) was only approximately 0.2. The aim of this work was to use stochastic simulation to investigate the effect that the distance between the SNP and causative mutation had on the accuracy of estimating additive and dominance effects of the causative mutation.

Balancing the competing needs of climate change, biodiversity and rural communities

The work of the UK Climate Change Commission (UKCCC) in recommending targets and options for reducing emissions of greenhouse gases is focusing attention on what agriculture and land use can contribute to deliver these targets. Although overall the major issue is the reduction of carbon dioxide emissions from energy use, agriculture and land use are significant emitters of methane and nitrous oxide. UKCCC has identified three main routes by which emissions can be reduced• Lifestyle change with less reliance on carbon intensive produce -eg switching from sheep, and beef to pig, poultry and vegetables.• Changing farm practices – eg to improve use of fertilisers and manures• Using new technology on farms – eg modifying rumen processes, anaerobic digestion.

Efficient ruminant production from grassland

Ruminant production in the UK is largely dependent on grasslands: approximately 52% of UK land is (improved) grassland and rough grazing. Herbage production from improved grassland can be over five times higher than that of indigenous swards (Davies et al., 1984) and these pastures account for the majority of ruminant (meat and milk) production from grassland the UK. They are also amenable to manipulation through the choice of species, variety and mixture of forages sown. Efficiency of production can be influenced at the levels of both the plant and the animal and by the nutrition and genetics of both. This paper examines strategies to increase production efficiency based upon optimising rumen fermentation linked to plant breeding approaches. In this way efficiency can be improved without recourse to diet manipulation with supplements, which is generally impractical at grazing. Although the rumen microbial population allows the ruminant animal to extract energy from otherwise unusable sources (i.e. fibres), the rumen is also the source of greatest inefficiencies in the use of nitrogen and energy. Degraded plant nitrogen that is not captured by the rumen microbes tends to be absorbed as ammonia, much of which is excreted as urea and contributes to ammonia and nitrous oxide emissions. Similarly, methane release from the rumen represents a waste of energy that could otherwise be used for production. Globally, these two processes result in ruminant livestock accounting for approximately a third of the methane emissions (Beauchemin et al., 2008) and half of the nitrous oxide emissions (de Klein and Eckard, 2008) from anthropogenic sources.

Effects of feeding pistachio hull and interaruminal infusion of urea on feed intake, ruminal and abomasum N-NH3 and blood metabolites in Iranian Balochi sheep

Due to binding tannin with protein and cellulose, it was hypothesized that pistachio hull tannin can decrease the digestibility of protein and cellulose. Pistachio Hull (PH) is the main pistachio by-product produced from the pistachio dehulling process. PH contained 12.7, 5.7, 16.6, 25, and 20% ash, EE, CP, NDF, and ADF, respectively. The nutritional responses to high levels of dried pistachio by-product in the diet have not been clearly researched. The main objective of this experiment was to evaluate the effects of feeding pistachio Hull at high levels on feed intake, ruminal pH, N-NH3 and blood metabolites in Balochi sheep.

The pigmeat supply chain: pre-assessment for a Life Cycle Inventory

Formulating the inventory of relevant commodities to assess the life cycle of goods or services (LCI) is highly demanding on time and resources (Suh et al., 2004). Collected information is not always satisfactory to take account of all possible sources of environmental burdens (E-burdens) produced in the commodity supply chain. Several pre-assessment methods have been proposed to serve this function, although these have identified limitations; lack of previous experience and use of subjective cut off criteria are the most frequent weaknesses found (Suh, 2006). An objective pre-assessment method was developed as part of a life cycle analysis (LCA) for different pigmeat supply chain (PSC) scenarios.

Effect of supplemented diet by sucrose and/or starch on blood cholesterol and some hepatic enzymes in Holstein steers

Carbohydrates are the major source of energy in diets fed to dairy cattle and usually comprised 60 to 70 percent of the total diet. They provide energy for both rumen microbes and the host animal. Sugars, starch, and other reserve carbohydrates such as fructans make up the non-structural carbohydrate (NSC) fraction and are major sources of energy for high producing dairy cattle (NRC, 2001). The fermentation of different NSC sources varies in digestion characteristics and in the profiles of organic acids produced (Hall and Herejk, 2001). Cholesterol is a structural lipid that is not required in the diet, since ample amounts are synthesized in the body. This lipid is a required component of most cells of the body. Cholesterol has received a great deal of attention in the nutritional and biochemical communities because of its strange metabolism in certain regions of the body, for example, the arteries that supply oxygen and other nutrients to the heart muscle (Brody, 1999). The aim of this study was to evaluate the effect of diets containing different type of NSC (sucrose or starch) on blood cholesterol and some hepatic enzymes namely serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) in Holstein steers.

Fermentation kinetic, chemical composition, organic matter degradation and metabolisable energy of three non-cultivated pastures located in the central plateau of Mexico

Approximately 80% of all production costs are related to the purchase of forages and other feeds in dairy enterprises in Mexico. Resource poor, smallholder (campesino) systems are heavily reliant on the use of maize stover, noncultivated/cultivated grass species and weeds to feed their dairy cattle, thus a nutritional understanding of local forage resources would be of considerable economic benefit. The objective of this study was to determine the nutritive value of non-cultivated pastures (NcP) across the growing season.

The effect of silver nano-particles (Nanosilver) on in vitro gas production of barley grain and lucerne hay

It is generally believed that heavy metals react with proteins by combining the thiol (-SH) groups, which leads to the inactivation of the proteins (Cho et al., 2005). Silver nano-particles (Ag-NPs) are being used vastly as a strong anti-germ product. In general, Ag ions, which have antimicrobial activity, are used as an antibacterial agent. The antibacterial activity of Ag ions is inhibits intracellular enzyme activity (Cho et al., 2005). Therefore, the other possibility can be considered that remaining Ag ions in Ag-NPs solution or dissolved Ag ions might affect bacterial growth. Recently, dairy farmers have tended to apply this anti-bacterial for sanitization of the environment (as a disinfectant material) of animals. However, the environmental residual effect of this anti-bacterial on ruminant microbial activity is still questionable. In the present study, a gas production technique was applied in order to determine the effect of silver nano-particles on in vitro gas production of barley grain and lucerne hay.