Lameness is a major economic and welfare issue for the sheep industry in the UK and Ireland. It has been estimated that footrot costs the UK sheep industry £24 million per year (Nieuwhof and Bishop, 2005). Although a feet lesion scoring system in sheep has been devised to monitor lameness, it is a time-consuming process. Locomotion scoring is well established in dairy cattle to record the incidence of lameness, but needs validation within sheep. The primary aim of the present study was to investigate the association between locomotion score and the level and pattern of feet lesion scores in sheep. There is some evidence that there are differences in susceptibility to lameness between breeds. Therefore, a secondary aim of the study was to investigate feet lesions and locomotion in four crossbred genotype ewes.

Sheep lameness is a major welfare concern as well as a challenge for sheep farmers because it is associated with reduced production and economic losses. The etiology of lameness can be either of environmental origin associated with housing, nutritional and genetic factors, or associated with the physiological changes during the productive life of sheep. Although, there is now a large body of research studies about lameness in meat producing sheep, such information in the literature regarding dairy sheep is very limited (Grogono-Thomas and Johnston, 1997; Winter, 2004). The Greek sheep industry is mainly based on milk production and is characterised by the recent establishment of many large, commercially run flocks. The aims of this study were to determine the prevalence of lameness (total number of cases at a given time) in such flocks of Chios sheep and to obtain data concerning the risk factors and type of management in relation to lameness.

Ovine foot rot is a chronic, contagious, and painfully debilitating bacterial disease affecting the hooves of sheep. It is the most common cause of lameness, resulting in a loss of an estimated £24 million annually (Nieuwhof & Bishop, 2005). The main causative agents Dichelobacter nodosus and Fusobacterium necrophorum; two symbiotic, Gram-negative, strictly anaerobic bacteria. Treatment is usually by regular footbathing with formalin (3% v/v) or zinc sulphate (10% w/v), antibiotic injection, or by topical application of an antibiotic combined with paring of the hoof. Natural methods of treatment have the potential of circumventing the increasing problem of antibiotic resistance, in addition to being favoured by consumers due to their perceived health and environmental benefits. Some plant extracts are known to exhibit multicomponental antibacterial actions. This study investigated the efficacy and practicability as treatments for ovine foot rot of three plant extracts all of which have been shown in numerous studies, mostly carried out in vitro, to kill a range of bacteria, when applied topically.

Recently much research has been carried out to enhance piglet survival by genetic improvement. Heritabilities of traits associated with piglet survival are generally low, but the genetic variation is large enough to provide improvement through breeding (Knol et al., 2002). However, correlations between some traits and/or between maternal and direct genetic effects have shown contradictory results, and not many studies have considered these effects. Reports of correlations between piglet survival traits and production traits are even fewer. The aim of this study was to estimate heritabilities of piglet survival traits and their genetic associations with other reproduction traits as well as production traits, using a Bayesian approach and appropriate models and genetic statistical procedures in order to obtain more accurate genetic parameters.

Predictive models have previously been applied to viral diseases such as porcine reproductive and respiratory syndrome virus (PRRSV) and have demonstrated that selection for resistance can reduce the likelihood of epidemics or the impact of disease on infected animals (Bishop and MacKenzie, 2003). Key components of selection programs for disease resistance are the characterisation of genetic variation and the identification of genetic markers or QTL associated with resistance to, or tolerance of, the pathogen. The growing evidence for genetic variation in host susceptibility to PRRSV has been described in the review by Lewis et al. (2007). This study seeks to develop data partitioning methodologies for describing the impacts of disease on pig performance, and estimate heritabilities traits affected by PRRSV.

Piglet survival is based on a complex interaction between the piglets own genetic component (direct genetic effects), the dams genetic contribution (maternal genetic effects) and environmental effects (systematic environmental such as year-season, common litter and individual environmental effects). Disentanglement of direct and maternal genetic effects needs a powerful design of genetic relationships. In order to accomplish this, a two generation selection experiment was designed with different selection groups for direct and maternal effects and cross-classification of these selection groups. Survival at birth and survival during the nursing period may have genetically independent components and would then be treated as different traits. In addition, piglet survival traits are reported to have low direct and maternal heritabilities and traits genetically associated with survival, such as birth weight, may result in a more efficient change in survival than using survival per se. Therefore, the objective of the research was to estimate the genetic parameters of direct and maternal genetic effects of survival and birth weight in order to enhance the selection strategies for piglet survival.

Footrot is an endemic disease of sheep, costing the British sheep industry an estimated £24M annually (Nieuwhof and Bishop, 2005). Estimates for the heritability of footrot in Australian data are as high as 0.3 (Raadsma et al., 1994), but this may differ in Britain because of different bacterial strains, sheep breeds and environmental conditions. The aim of this study is to determine the heritability and repeatability of resistance to footrot in Scottish Blackface (SBF) and mule sheep at different ages, and to assess if breeding for resistance to footrot is a credible option for British sheep breeders.

The presence of footrot in a flock can have serious implications for animal health, welfare and productivity. Associated increases in treatment and prevention costs, as well as losses in performance, have led to a notable interest in using breeding to control footrot in sheep. Current breeding indexes for UK hill sheep such as the Scottish Blackface, include both lamb and maternal traits, and have led to improvements in economic returns. So that breeding for resistance to footrot can be evaluated in the context of multi-trait selection programmes, the genetic relationships with current breeding goal traits must be quantified. The objective of this study was to identify important environmental factors affecting footrot prevalence and to estimate genetic parameters between footrot severity and other traits used in current UK hill sheep breeding indexes.

Fertility has been shown to have an unfavourable genetic relationship with milk production in Holsteins so continued selection for milk production will exacerbate the decline in fertility in the absence of information on daughter fertility. The only way to reverse this genetic trend is to breed dairy cows additionally for fertility. But dairy farmers have historically had no access to fertility information when they purchase semen. It is therefore vital that fertility is included in selection programmes and that farmers can choose to inseminate their cows with semen from bulls with a positive predicted transmitting ability (PTA) for daughter fertility. Although of low heritability, fertility traits have been shown to have sufficient genetic variation and have recently been made available nationally for the Holstein-Friesian breed (Wall et al., 2003). The aim of this study was to investigate the feasibility of estimating fertility indices for Ayrshire (AYR), Guernsey (GUE) and Jersey (JER) dairy cows.

Digital dermatitis (DD), an infectious skin disease of cattle, is considered an important cause of lameness in dairy herds due to the resulting pain, discomfort and impaired performance (Read and Walker, 1998). DD has been associated with reduced fertility and a shorter lifespan (LS) as well as a decrease in milk production and generally reduces the overall wellbeing of the cows. As part of the UK type classification scheme, field officers record whether or not cows exhibit signs of DD during routine type evaluation. The aim of this study was to estimate the heritability of DD and genetic associations between DD, type traits related to feet and legs, with fitness-related traits and production.

Energy evaluation systems translate animals’ requirements for net energy (NE) into feed metabolisable energy requirements (MER). The Feed into Milk (FiM) project resulted in a new system for predicting the MER of dairy cows (Thomas, 2004). In contrast to AFRC (1993), the FiM system is (almost) independent of feed quality, like the system proposed in 1994 by Tolkamp & Ketelaars (T&K). To translate NE requirements into MER, FiM requires nine parameters, while for all cattle that are fed (near) ad libitum T&K require only one. Here we analyse how these parameters contribute to the differences in prediction of daily MER between the two systems and what the causes of these differences are.

Supplemental fat is often used to increase the energy density of diets for dairy cows, with the aim of improving tissue energy balance (TEB), milk production and herd fertility. In this study, the effects of supplemental calcium salts of palm fatty acids (CSFA) on production parameters, dry matter intake (DMI) and TEB were assessed in highly productive, early-lactation cows offered typical UK diets.

Rapid breakdown of herbage proteins in the rumen and inefficient capture of nitrogen (N) by the rumen microbial populations are a major source of N loss and pollution in pasture-based ruminant agriculture. Degree of cell damage during mastication and ingestion varies between grass species with consequences for release of cell contents (protein, sugars and lipids) into the rumen (Kim et al., 2008). Consequently, grazing cattle on different grass species may provide an opportunity to manipulate N efficiency. The purpose of this study was to compare N utilisation efficiency by dairy cattle grazing grass species differing in chemical and morphological characteristics.

Reducing the phosphorus (P) content of dairy cow diets has the potential to help reduce P losses. However, P is an essential nutrient, and has many roles within the body, while in addition, rumen microbes have a requirement for P (NRC, 2001). Thus, if dietary P levels are inadequate, this could have a negative effect on rumen function, nutrient utilisation and energy metabolism. An experiment was undertaken to examine the effect on energy metabolism and P utilisation of offering dairy cows diets containing reduced levels of dietary P.

There has been growing public concern with regard to the effects of heavy metals excreted by animals on the environment. Heavy metals can be lost from manure and slurry to ground and surface waters, and subsequently affect water quality (Van Horn et al., 1996). In regions of high domestic livestock production, farmers are therefore seeking means to reduce the quantity of heavy metals excreted by animals and subsequently onto the land (Van Horn et al., 1996). The objective of this study was to establish the effect of two levels of dietary Zn inclusion in two different forms (organically chelated vs. inorganic) on apparent absorption and retention in dairy cattle.

Neonatal diarrhoeas are a major problem in bovine husbandry. Antibiotics are usually utilized as medicine but a prevention based on natural methods could be of interest. Lactoferrin (Lf) is a glycoprotein naturally found in milk. It is known for its many useful properties for animal health, in particular for its immunomodulator, antimicrobial, anti-inflammatory and antiviral effects. The lactoperoxidase system (LpS), an enzymatic system, also present in milk, possesses effective antimicrobial properties. It is composed of lactoperoxidase (Lp), thiocyanate and H2O2. A synergy between Lf and LpS has been reported. The aim of this study was to assess the effects of Lf and of the association Lf-LpS as oral supplements to newborn dairy calves in order to improve health and production parameters.

Cull cows comprise about 44% of all cattle slaughtered at Irish meat factories in 2006; which was an increase of 6% from 2005. Between September and December 2006, 18% of cull cows failed to achieve P+3 carcass classification compared with 12% for the remainder of the year (DAF, 2006). There is a large proportion of cows slaughtered in November, which suggests that unfit (low bodyweight and condition score) cows are being presented for slaughter at the end of lactation without finishing prior to slaughter. Farmers who are finish feeding cull cows have an interest in alternative feeding regimes i.e. pasture and/or forage use for a more economical beef supply due to increasing concentrate costs, however present farm practice and culling decisions made by the dairy farmer often excludes this as a real possibility. The objective of this study was to compare days to slaughter, average daily gain, and final live and carcass of cull dairy cows subjected to four over-wintering strategies prior to a pasture based finishing diet.

Yeast has been used as a means of manipulating rumen fermentation to improve production performance because of the effect on stimulating cellulolytic mico-organisms in the rumen that increase fibre digestion, alter acetate to propionate ratios and increase microbial protein flow to the duodenum (Wallace and Newbold, 1992). Williams et al. (1991) found that animals offered high energy diets had decreased rumen lactic acid concentrations, which is associated with higher rumen pH and characteristic of more stable rumen fermentation. Low rumen pH has been associated with poorer hoof quality (Westwood et al., 2003). This research aimed to assess the effect of the inclusion of live yeast in total mixed rations on milk yield, lameness, sole bruising and hoof characteristics.

A short herd lifespan is a significant economic loss to the dairy industry, with infertility a major cause. Conception rates to first service have fallen from around 60% in the 1970s to 40% by 2000. The re-establishment of ovarian cyclicity after calving is important in determining the timing of conception which should be around 80 days postpartum (PP) to maintain yearly calving intervals. Insulin-like growth factor-I (IGF-I) is thought to influence ovarian activity at this time. We have previously shown that pre-pubertal IGF-I levels are related to growth and can predict concentrations around first calving. This study investigated IGF-I, insulin, glucose, urea and betahydroxybutyrate (BHB) concentrations before and after first calving in typical UK herds in relation to measures of fertility during the first lactation.

Calving dairy heifers at 2 years of age, with the achievement of high levels of maturity (live weight) at service (65%) and calving (85 %) increases lifetime productivity (Margerison and Downey, 2005). Recent research into dairy heifer nutrition has focused on increasing calf development, live weight gain and development of stature, while minimising tissue fat deposition, particularly in mammary parenchyma (Serjrsen, 2005). The use of increasing feeding levels and growth rates for dairy heifers during the prepubertal period have been the focus of recent research and much of this has involved differing sources and levels of energy and protein (Hill, 2005; Tannan, 2005) and the use of probiotics and natural plant extracts to replace antimicrobials. In addition to these considerations, the world milk supply dynamics and increasing global demand for milk results in the need to consider using lower levels of whole milk and alternatives to skim milk products for dairy heifer rearing. The aim of this research was to compare the effect of offering differing levels of whole milk and a combination of plant extracts on the growth, development and weaning age of New Zealand (NZ) Holstein Friesian and NZ Holstein Friesian dairy heifers.