Norway has adopted a multi-trait selection programme within its Norwegian Red (NR) dairy cow population for over thirty years, in contrast to breeding programmes with the Holstein-Friesian (HF) breed, which have, until recently, focused primarily on milk production. As a result, evidence from Norway suggests a dairy cow population with high levels of fertility and a relatively low incidence of mastitis. Consequently, there is considerable international interest in the NR breed as a means of overcoming some of the fertility, health and longevity problems that currently exist within the HF breed. To examine the potential of the NR breed, an experiment was established on 19 commercial dairy farms to compare the production, fertility and longevity of animals of the NR and HF breed across a range of production systems.

Fertility traits have been included within breed selection programmes for the Norwegian Red (NR) dairy cow population in Norway for over thirty years. As a consequence, a 60 day non-return rate to first artificial insemination (AI) of 72.5% was recently calculated for NR cows in Norway (Garmo et al., 2008). In view of this long term breeding programme, and current fertility performance within Norway, there is considerable interest in the NR breed as a means of overcoming the high levels of infertility that currently exist within the Holstein-Friesian (HF) breed. However, farming systems within Norway are very different from those within the UK, with herd sizes in particular being much smaller. Thus an experiment was established on 19 commercial dairy farms to compare the fertility performance of cows of the NR and HF breeds.

The role of the dairy herd as a provider of beef has proportionately reduced as the dairy animal has become more specialised over the years. High milk production per cow and a decreasing national herd has resulted in a reduction in calves born, and genetic changes have led to dairy bred bull calves being less suited to beef production. This has led to the market for purebred dairy bull calves being severely curtailed and, in some instances, the male purebred calf has had no value. The study develops tools to allow Holstein-Friesian (HF) dairy breeding goals to include muscling and carcass quality to help improve the value of dairy bred bull calves as beef animals.

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.

Silkworms are agricultural insects producing silk fibres. Because of economic importance of sericulture, breeding programs are performed in order to improve bio-economic traits of lines (production and resistance traits) and also developing new lines containing interesting characteristics. Silkworms in Iran are reared twice a year, in spring and autumn. Spring is the natural rearing period of silkworms because of good environmental conditions. In autumn the quantity and quality of the cocoon produced by silkworm lines decreases due to increasing mortality and access to mulberry leaves with low nutritive quality. This decrease in performance will be lower in the lines which are genetically resistant to severe environmental conditions. Therefore, it is necessary to breed and develop new silkworm lines suitable for such a situation. It is obvious that silkworm lines having lower performance but higher resistance can be introduced for autumn season rearing. Appropriate breeding programs have to be defined and conducted for the autumn rearing lines. Thus, we have to estimate genetic parameters of autumn and spring lines separately when reared in each season. The present study was undertaken to identify heritability of important traits in the spring and autumn seasons for 6 silkworm lines.

There is a large body of research investigating the nutritional needs of the dog at different life-stages and the use of different feed ingredients in commercial diets (Clapper et al, 2001; Schroeder & Smith, 2008). Despite this, though there has been relatively little published work looking at the role the large intestine plays in nutrient digestion in the dog. The dog’s gastro-intestinal tract has been compared to the cat’s in terms of relative length. However the cat is a true carnivore and has little need to ferment fibre from the diet, whereas the dog is a scavenger and will consume a much wider range of food, and therefore may need to ferment fibrous material from the diet. The dog may therefore require a more developed large intestine to harbour a microbial population to aid in the digestion of this fibrous material. This study was performed to determine differences in digestion of nutrients in this segment of the canine gastrointestinal tract.

The increasing use of functional foods as a non-invasive way to modulate and optimise human immune system function is now beginning to transfer into the production animal and companion animal areas as owners search for alternative ways of maintaining and improving animal health. To date, dietary supplementation trials, primarily carried out in humans and mice have demonstrated the ability of a wide variety of bioactive ingredients such as probiotics and specific ratios of omega-3 and omega-6 fatty acids, to modulate a range of immune functions. However, little data exists for other animal species such as the cat or dog and in particular the working dog. Working dogs are a vital component of the farming sector in New Zealand (NZ), however, many animals are subjected to inadequate nutrition that may compromise their short term performance and exercise recovery, and long term usefulness to the farmer (Jerram, 2005). In this study we assessed the potential benefits of dietary supplementation with a canola oil-based dietary supplement (canola is a rapeseed variant), formulated at Massey University, and manufactured in NZ, to enhance a number of immune parameters in the working dog.

Digestibility trials enable researchers to determine the amount of nutrients an animal absorbs and utilises from feed. There are a number of methods available, with the most common being the measurement of total feed intake and total collection of faeces. However, in situations where it is not practical to conduct a total collection trial, indigestible markers are used in conjunction with grab-sampling or sub-sampling techniques. To date, the most common marker used in dog studies has been chromium oxide (Cr2O3; Hill et al., 1996), with little data available on the suitability of other markers such as titanium dioxide (TiO2). A major problem in using Cr2O3 as an indigestible marker is poor repeatability and agreement between laboratories in the determination of Cr2O3. This has led to variable results due to incomplete and inconsistent recovery in excreta (Sales and Janssens, 2003). However work on other species comparing the use of TiO2 and Cr2O3, has demonstrated that TiO2 was a more accurate marker (Jagger et al., 1992). This study was performed to determine the digestibility of two diets, a low (LN) and a high nutrient (HN) diet using TiO2 or Cr2O3 as indigestible markers. The two different quality diets were used to investigate if digestibility affected marker recovery.

Previous studies at this centre have shown that extended grazing ewes in mid (Keady et al., 2007, Keady and Hanrahan 2009b) late (Keady et al., 2007) or throughout (Keady et al. 2007, 2008, Keady and Hanrahan 2009a) pregnancy increased lamb birth and weaning weights relative to progeny from ewes which were housed unshorn. Stocking rate needs to be reduced dramatically to facilitate year round grazing (Keady et al. 2008) as herbage availability during early autumn (to prepare ewes for mating, finish remaining lambs and enable a sufficient proportion of the farm to be rested to build up sufficient herbage for extended grazing) is the major limitation (Keady and Hanrahan, 2007). Keady and Hanrahan (2009b) showed that increasing herbage allowance to ewes in mid pregnancy decreased herbage utilisation but increased forage intake, ewe condition and subsequent lamb birth and weaning weights. The aim of the current study was to evaluate the effects of herbage allowance and frequency of allocation to ewes in mid pregnancy on ewe and subsequent lamb performance. Furthermore the effects of extended grazing management on subsequent herbage yield and ground cover were also evaluated.

Rations for pregnant ewes in the UK are often based on grass silage. However, due to a number of factors, the cost of producing high quality grass silage has increased significantly in recent years so lower cost alternatives need to be investigated. Production of forage maize has the potential to reduce forage costs on mixed beef/sheep farms, with high dry-matter yields (comparable to that of a 3-cut silage system) of high quality maize silage possible from a single harvesting operation (Easson and Fearnehough, 2000). However there is limited information on the effects of feeding maize silage to pregnant ewes. Alternatively, grass silage could be eliminated from rations by feeding high grain diets. The aims of this study were to evaluate the effects of replacing grass silage with either maize silage or concentrates on the performance of housed pregnant ewes and their lambs.

Ewe replacements are a major cost in sheep production. This cost is influenced by replacement rate and rearing expense which is a function of plane of nutrition offered during the first winter, subsequent grazing season prior to joining at 18 months of age and during pregnancy prior to lambing as 2-tooth ewes. There is a paucity of data on the impact of plane of nutrition between 6 months of age and first lambing as 2-tooth ewes on body size and subsequent productivity. The weight of lamb carcass produced per ewe, which is influenced by litter size, lamb survival and growth rate, is the main factor affecting output per ewe. Plane of nutrition at different stages during the rearing phase, genetic potential for prolificacy and their potential interactions may be important. The aim of the current study was to evaluate effects of plane of nutrition during the first winter, subsequent grazing season and during first pregnancy, and potential interactions, on ewe body size and productivity and subsequent lamb performance using two breed types with contrasting prolificacy potential.

The Welsh Mountain sheep is a numerically important breed in the UK, but its lambs are characterised by low slaughter weights and poor carcass conformation. The reduction in stocking rates that is often associated with environmental conservation schemes, offers the potential for the use of larger ewes. Crossbreeding allows more rapid genetic change to be undertaken than would be possible from selection within breeds, and affords the potential to utilise heterosis and improve the quality of subsequent crosses with the Bluefaced Leicester. This work compared the survival and productivity of purebred Welsh Mountain ewes with a range of crossbred ewe types maintained in a hill environment.

Hill sheep flocks in the UK are dominated by purebred ewe genotypes, with the Scottish Blackface being the most common. However a long term decline in economic returns, combined with recent changes to the Common Agricultural Policy, has lead many hill sheep producers to consider keeping crossbred ewes to exploit the benefits of hybrid vigour for lamb survival and to introduce beneficial traits for prolificacy, ease of lambing and carcass quality. In 2001, a major on-farm research programme was initiated to evaluate the performance of a range of crossbred ewe genotypes for the Northern Ireland hill sheep sector. Provisional data has already identified that retaining Lleyn X Blackface and Texel X Blackface ewes can improve lamb output at weaning by up to 10% relative to purebred Blackface ewes (Speijers et al., 2007). However, ewe longevity is a major issue for hill flocks, where the annual replacement rate often exceeds 20%. Therefore it is inappropriate to evaluate crossbred ewe genotypes based on average annual performance alone, and the aims of this study were to investigate the lifetime performance of a range of crossbred genotypes under hill conditions.

Nutrient intake during pregnancy affects foetal development and placental function in a range of species, often with long-term effects on offspring viability. Maternal nutrient supply is believed to affect the ability of the placenta to deliver nutrients to the foetus (Fowden et al., 2006). In ruminant species, the majority of placental nutrient transport occurs in specialised structures called placentomes, which are categorised into 4 types (A-D) based on their morphological appearance. In type A placentomes, maternal tissue surrounds foetal tissues, whereas type D placentomes are typically everted and have a higher ratio of foetal:maternal tissue. It has been suggested that the distribution of placentome types may reflect the ability of the placenta to deliver nutrients (Vonnahme et al., 2006). This study tested the hypothesis that levels of under-nutrition typically encountered by hill ewes during pregnancy would alter the distribution of placentome types and that the relationship between ewe nutrition and placentome type would differ between breeds selected for lean tissue growth (such as the Suffolk) compared to less selected breeds (such as the Scottish Blackface).

Nutrient intake during pregnancy affects foetal development and placental function in a range of species, often with long-term effects on offspring viability. Maternal supply and placental transport of amino acids are key to delivering amino acids for foetal metabolism. Maternal under-nutrition has been shown to reduce both maternal and foetal amino acid concentrations even after a period of re-feeding (Kwon et al. 2004). Intriguingly whether sheep have been adapted to a harsh environment or not appears to influence the extent of any reduction (Jobgen et al. 2008). The present study therefore tested whether plasma amino acid concentrations differed between Scottish Blackface (B) sheep adapted to a hill environment and a lowland breed (Suffolk, S) selected for lean tissue growth when challenged by a period of under-nutrition.

Nutritional status in early and mid-pregnancy can affect subsequent offspring productivity. For example, plane of nutrition in early and mid-pregnancy has been shown to have a significant effect on carcass characteristics, with male offspring of dams offered a low plane diet in early pregnancy having poorer carcass conformation and greater fat depths over the muscle L. dorsi than lambs of dams offered medium or high plane diets (Muñoz et al. 2008a). Supplementation with selenium (Se) during this period had positive effects on measures of lamb viability and survival (Muñoz et al. 2008b). The aim of the current study was to investigate the effect of plane of nutrition and selenium supplementation of ewes in early and mid-pregnancy on the meat quality of the male offspring.

Nutrition has a major impact on the fatty acid composition of beef, despite high levels of biohydrogenation of dietary polyunsaturated fatty acids (PUFA) in the rumen (Scollan et al., 2006). The latter may be ameliorated by feeding rumen-protected lipid. Grass relative to concentrate feeding results in beef characterised by a higher content of n-3 PUFA and excellent colour shelf life. This study investigated the effects of including a PUFA-rich lucerne-based plant extract (PX) on the fatty acid composition and meat quality in beef.

In Northern Ireland grass silage is the basal forage for beef cattle during the winter feeding period. Increasingly however, other ensiled forages are being considered due to their potentially lower cost and perceived conservation and nutritional attributes. Wholecrop cereals such as wheat have been shown to improve dry matter (DM) intake but not animal performance (Keady et al, 2007). With increasing volatility in world markets creating major fluctuations in protein prices, interest has increased in home grown protein sources. High protein legumes with low input costs, such as lupins have given reasonable animal performance when offered as a monoculture. However, limited scientific research has been undertaken on the role of legumes in combination with a cereal as a bi-crop for finishing beef cattle. Consequently the objective of the current study was to evaluate the effects of legume/cereal wholecrop offered either alone or in combination with grass silage on the performance of beef cattle.

The European Union Nitrates Directives set a limit on the amount (170 kg/ha) of manure nitrogen (N, = faecal N + urine N) that may be applied to land each year. This limit has very significant implications for stocking rates on intensive livestock farms. Consequently, there is increasing interest in developing mitigation strategies to reduce N output in faeces and urine in animal production systems. The objectives of the present study were to evaluate the effects of dietary crude protein (CP) concentration on the efficiency of N utilisation in lactating dairy cows.

Improving the sustainability and overall longevity and health of modern Holstein Friesian (HF) dairy cattle is essential in order to maintain overall farm profitability. Prolonged negative energy balance in early lactation can result in metabolic stress, as well as long term problems with fertility (Pryce et al., 2004). In addition, maximising the efficiency of nitrogen (N) utilisation by strategies such as reducing the crude protein content of the diet is of crucial importance in minimising the environmental impact of dairying. The aim of this study was to evaluate the effect of a range of nutritional strategies on milk production, energy balance and efficiency of N use in early lactation.