The health and welfare of organically-farmed livestock are of concern due to restrictions on the use of veterinary medicines. Non-organic systems control nematodes using prophylactic treatment with anthelmintics. Routine drenching is banned within organic agriculture, and farmers are encouraged to find alternative methods of control, for example grazing management practices. This study investigated the level of nematode parasitism in organic and non-organic dairy herds around Scotland.

Excessive phosphorus (P) inputs to agricultural systems contribute to the problem of eutrophication of water courses, with dairy farms often implicated as potential sources of P pollution. To help address this issue, there is currently considerable interest in reducing the P content of dairy cow diets. For example, recent research has indicated that the P content of dairy cow rations can be reduced without any negative effect on animal performance (Wu and Satter, 2000). The objective of the current study was to examine the effect of reducing dietary P levels over four successive lactations, on dairy cow fertility.

Phosphates represent one of the primary sources of water pollution in Northern Ireland, an issue of particular concern in view of existing EU legislation, such as the Water Framework Directive. Inputs of phosphorus (P) to agricultural systems contribute to this problem, with dairy farms often implicated as a potential source of P pollution. Part of this problem can be attributed to the fact that large quantities of P are imported onto dairy farms in concentrate feeds which tend to be high in P (7.3 g P/kg DM in a survey of 35 winter concentrates for dairy cows). However, recent research has indicated that the P content of dairy cow rations can be reduced without any negative effect on animal performance (Wu and Satter, 2000). Nevertheless, the rations offered in this study were very different from those commonly offered within grassland based dairy systems in the UK. Consequently a study was established to examine the effect of reducing dietary P levels on cow performance, with the study being conducted over two successive lactations. The long-term nature of the study was deemed necessary as cows can mobilise bone phosphorus reserves for milk production when dietary phosphorus levels are inadequate.

Optimisation of supplementation of forage with concentrates is essential to improve efficiency and economic sustainability of dairy cow production systems, as well as reducing the environmental impact of intensive dairy farming. However, continuing fertility and health problems indicate that we are not responding effectively to the needs of high genetic merit dairy cows in terms of current feeding and management strategies. A programme was initiated to examine the consequences of nutritional manipulation of dairy cow diets on animal performance in order to attempt to reprogramme the nutrient partitioning of the animal towards maintenance of body reserves rather than excessive milk yield and to potentially alter the lactation curve to give a flatter curve of milk production.

The imminent ban on the use of antibiotics and antibiotic growth promoters in animal feed in EU member states from 1st January 2006 provides a new focus for the development of alternative strategies to augment immune function in farm animals. In recent years there has been an increased interest in the ability of certain nutraceuticals to enhance immune response and consequently improve health status. For example, there is now some evidence for non-ruminants that consumption of polyunsaturated fatty acids (PUFA) including eicosapentaenoic acid (EPA; 20:5n-3), docosapentaenoic acid (DPA; 22:5 n-3) and docosahexaenoic acid (DHA; 22:6n-3), belonging to the n-3 fatty acid series, can affect immune function. However, both positive and negative effects have been reported depending on the specific fatty acid and amount used (see review by Calder, 1998). There is a dearth of information, however, on the possible effects of PUFA on immune status in ruminants. One recent study (Wistuba et al., 2005) suggests that fishoil may act as an immune stimulant in grazing beef calves. The objective of the current study was to examine the effect of level of dietary omega-3 fatty acid supplementation on the haematological profile and indicators of immune function in cattle.

Benefits when yeast cultures are added to ruminant diets may include increased intake, ruminal fibre digestion, reduced ruminal accumulation of lactic acid, increased growth efficiency in beef cattle and increased milk yield in dairy cows. However, the effects on milk performance can be variable, with small or negative responses being reported, as well as positive effects. Part of this variation may be attributable to differences in animal potential and basal diet, and it has been suggested that the greatest benefit may occur in high yielding cows when fed diets high in high starch. The objective of the current experiment was to determine the effect of a yeast culture on the intake and performance of high yielding dairy cows fed a complete diet that was high in starch.

Reproduction and health in addition to milk production are the principal factors that are influencing dairy farm profitability. The dairy industry in Iran has changed dramatically in the last decade. The shift toward more productive cows and larger herds is associated with a decrease reproductive efficiency (Heravi Moussavi et al., 2004). Increased knowledge about the principal causes of reduced fertility is essential. It was shown that clinical mastitis during early lactation markedly influenced reproductive performance of Jersey cows (Barker et al. , 1998). Recently, survival analysis was used to assess the effects of diseases on days from calving to conception. Survival analysis allows for a more appropriate management of censored data and time-dependent covariates, which are very common in the study of variables such as days open, days to first breeding, and days from first breeding to conception (Maizon et al., 2004). The objective of this study was to evaluate the effect of postpartum mastitis on days open in Iranian Holstein dairy cows.

Greater feeding value of lucerne silage than lucerne hay has been a common finding of ruminant feeding studies in tropical countries. However, during ensiling, a large proportion of the crude protein (CP) in lucerne is broken down to non protein nitrogen (NPN), (Broderick et al. , 1995). Additives such as formic acid may reduce proteolysis during lucerne ensiling. The objective of the present experiment was to compare the nutrient content, and ruminal and post-ruminal dry (DM) matter and protein disappearance of lucerne silage treated with urea and formic acid.

Rearing pre-weaned calves is one of the most challenging tasks on a dairy farm. Intensively reared calves are typically separated from dams within 24 hours of birth and fed restricted quantities of either whole milk or milk replacer until weaning. In contrast, a calf left with its dam will consume significantly more milk which leads to increased weight gain and improved health (Albright and Arave, 1997). Milk can be provided through ad libitum feeding systems with artificial teats allowing calves to consume more milk than with the traditional, bucket fed system. Milk replacer is a commonly used substitute feedstuff for whole milk on many calf rearing units in the UK. Milk replacers are formulated to meet the nutritional requirements of the pre-weaned calf but typically contain significantly less fat, on a DM basis, than whole milk. The aim of this trial was to investigate the effects of feeding whole milk versus a milk replacer to calves on a cold ad libitum basis on the milk and concentrate feed intakes and liveweights between the groups.

Various ethanol solutions have been used to alter ruminal degradation of soya-bean meal (SBM) protein, thus increasing its post-ruminal availability. The best ethanol solutions for this purpose in wide range of ethanol concentration were reported to be 600 and 700 ml/l by Van der Aar et al. (1984), and Lynch et al. (1987), respectively. However in the literature, there is no degradability data concerning comparison of narrow range of ethanol solutions. Therefore our objective was to compare crude protein (CP) and true protein degradation characteristic of 500, 600 and 700 ml/l ethanol treated SBM.

Introduction The recent change in beef cattle support payments from headage to area based payment and relatively low cereal prices could see an increased interest in earlier finishing of beef cattle. An increased number of producers are therefore likely to adopt intensive cereal finishing systems for beef cattle. Antibiotic based feed additives e.g. monensin sodium, have been successfully used for over 40 years to manipulate microbial activity and improve beef cattle performance especially in cereal beef systems. The use of monensin sodium was banned from January 2006 and therefore there is a requirement to find alternative ‘natural’ products that can improve the efficiency of beef production with cereal based rations. Acid Buf is a natural rumen buffer derived from calcified seaweed (Lithothamnium calcareum) ground to a very fine particle size. It contains calcium and magnesium as well as a range of trace minerals. The claimed characteristics of Acid Buf are: excellent acid absorbency, long term buffering activity and fine particle size for optimum availability to help overcome problems with acidosis in high starch based rations. The objective of this experiment was to determine the effect of feeding Acid Buf on the performance of intensively finished dairy-bred beef cattle fed ad libitum cereals.

We have reported previously (Sadeghi et al., 2005; Sadeghi and Shawrang, 2005) on the use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis technique (SDS-PAGE) to study subunits degradation of soya-bean meal (SBM) and rapeseed meal (RSM) proteins in the rumen. As far as we are aware, there is no published information concerning degradation rates of protein subunits of feedstuffs. The objective of this study was to investigate degradation rates of SBM and RSM protein subunits in the rumen.

A preliminary investigation by Marsh and Gibson (2004) indicated that cracked head-cut urea treated whole crop wheat could offer beef producers the opportunity to achieve high levels of animal performance and reduce feed costs per kg gain when compared to diets based on rolled barley for intensively fed beef cattle. The objective of this experiment was therefore to evaluate crop yield and beef cattle performance from winter wheat and winter barley crops harvested both conventionally and at the end of physiological grain fill (approx 70% dry matter), the latter being made into cracked head-cut urea treated whole crop.

Grass silage can be less attractive as a ruminant feedstuff when compared to alternative forages due to relatively modest yields obtained in a single harvest, variability in digestibility and ensilability, coupled with ever increasing costs of production and effluent management. The composition of feeds consumed differs markedly from the nutrients available for metabolism due to the modifications caused by microbial fermentation in the rumen. Volatile fatty acids produced in the rumen as a result of the fermentation of feed are the major source of energy supplied to the ruminant. The objectives of this experiment were to determine the effect of alternative forages on intake, rumen fermentation and plasma metabolites in beef cattle.

Previous work has shown that the biohydrogenation of fatty acids is different in solid and liquid fractions prepared from rumen fluid (Dorel et al. , 2005). This study aimed to relate this observation to differences in the microbial population in the different fractions. Molecular techniques allow the rapid investigation of microbial numbers and diversity in environmental samples. However, description of the microbial diversity can be affected by the efficiency of DNA extraction from samples as it is known that it is harder to quantitatively extract DNA from some microbes than others (Clement and Kitts, 2000). The aim of this study was to investigate different protocols for preparing samples and extracting DNA from different fractions of rumen fluid, in terms of both the numbers and diversity of bacteria that could be recovered.

Sugarcane and sugar beet molasses are dark brown juices which are remained after crystallization or concentration of sugar syrup. Problematic nature of molasses prompted sugar producers to solve difficulty of preservations, transportation, mixing and the problem of sticky concentrate mixtures or its hard handling in cold weather. Thus, in recent years, Iran sugar industry made a shift to develop dehydration technology of molasses, but it was not clear weather the applied technology could be efficient employed and if such a product could replaced by sugar beet pulp which is in rare in cold seasons. This trial performed to study if Dry Sugar beet Molasses (DSBM) could be efficiently replaced with sugar beet pulp with no side effects.

Lowering the costs of suckler cow production systems is one of the key challenges facing the beef industry as a result of recent changes in the Common Agricultural Policy which has resulted in farm based subsidies being decoupled from food production. One of the largest costs associated with production in spring calving suckler cow systems is the costs of over-wintering the non-lactating cow. The capital tied up in buildings is a major component of these costs in countries such as the UK where the relatively harsh winter environments have traditionally led to many cows being housed and fed conserved forages over the winter months to ensure excessive losses in cow liveweight (LW) and condition score (CS) do not occur. Applied studies are required to develop systems which allow non-lactating suckler cows to be out-wintered under UK conditions without excessive LW and CS loss as a means of reducing production costs. The objective of the current study was to determine LW and CS changes in non-lactating suckler cows when managed under a range of outdoor conditions from November to March.

Previously reported results indicated that feeding heifer calves more milk replacer increased growth rates in the pre-weaning period, but had little or no effect on plasma protein concentration. However, increasing the crude protein content of milk replacer from 230 to 300 g/kg, had no effect on growth rates but plasma total protein and plasma urea concentrations increased (Wicks et al. , 2005a, b). Kohn et al. (2005) showed that plasma urea was an indicator of nitrogen excretion. An experiment was therefore initiated to investigate the influence of level of milk replacer feeding and the crude protein content of the milk replacer on the nitrogen excretion of calves.

Lameness in adult ewes can result in reduced prolificacy, lower milk yields and a reduced wool yield (Anon, 1992) and a report by DEFRA (2003) showed 90% of sheep farms had lameness problems. The profiles of fatty acids found in claw lipids from lame cattle have been shown to be different to those in sound animals (Offer et al. 2000). Although the underlying mechanism behind this remains unclear, this offers the possibility of influencing the degree of lameness by manipulating claw lipid composition (Offer et al. 2000). Inoue et al. (1986) have shown that human epidermis with higher levels of lipid also has higher moisture content and bound water content. As water is known to modulate the mechanical properties of claw horn (Baillie et al. 2000), it may be postulated that a change in lipid content through supplementation may allow manipulation of the biomechanical properties of the claw. This may be important in lameness where brittle claw horn is manifest. This study investigates whether a dietary lipid supplement, protected against rumen fermentation, may be a useful tool in controlling the properties of the sheep claw.

Digital dermatitis is a major challenge to the UK dairy industry, affecting more than 70% of farms (Dawson, 1998). It is a highly contagious condition that affects the skin next to the claws and may even extend to the claws themselves. The extent to which digital dermatitis is affected by different management systems, and its relationship with other hoof health issues remains unclear. The aim of the current study was to assess the effects of different rearing regimes on the occurrence of digital dermatitis in dairy herd replacements. In addition, relationships between digital dermatitis and the severity of other hoof health parameters, including sole lesions, level of heel erosion and locomotion score, were also examined.