Texel Muscling QTL (TM-QTL) and LoinMaxTM (LM-QTL) are located on chromosome 18 in Texel and Poll Dorset sheep, respectively, and have been shown to positively affect muscling of the loin in crossbred lambs carrying one copy of the QTL (Macfarlane et al., 2008, Masri et al., 2009). MyoMaxTM (MM-QTL), found on chromosome 2 of Texel sheep, increases muscling and decreases fatness in lambs of different genetic backgrounds (Campbell and McLaren, 2007). No differences in live weights, carcass weights or growth rates have been associated with these QTL to date. However, there is further need to investigate the effects of the three QTL on growth patterns in commercial crossbred populations, where fast-growing slaughter lambs of good carcass weights and quality are a prerequisite.

LoinMax (LM-QTL) increases M. longissimus dorsi (MLD) area and weight by 11% and 8% respectively (Nicoll et al., 1998). It was found to segregate in Australian Poll Dorset sheep (Banks, 1997) and has been mapped to chromosome 18 (Nicoll et al., 1998). The UK sheep industry may benefit from using LM-QTL to increase yield of the highly priced loin region. However, before being utilised, the effects of LM-QTL need to be verified in a genetic background typical to the stratified structure of the UK sheep industry.

Normal development of ovarian follicles leading to ovulation depends on interactions between the oocyte and somatic cells in the follicle as well as the general physiological milieu. The oocyte-secreted molecules bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF9) are essential for normal ovarian follicle growth and function (Shimisaki et al. 2003). Mutations in both BMP15 (FecXG) and GDF9 (FecGH) have been shown to be segregating in the Cambridge breed and ewes that are heterozygous carriers of either of these mutations have greatly increased ovulation rate while homozygous carriers of either mutation are sterile with a typical ovarian hypoplasia (Hanrahan et al. 2004). The sterility is due to failure of follicular development to progress beyond the primary follicle stage. However, not all cases of ovarian hypoplasia in Cambridge ewes could be explained by these mutations and sequencing of the entire coding regions for these genes did not reveal any mutations that could account for their typical sterile phenotype (Hanrahan et al. 2004). It was suggested, based on pedigree analysis of the four ‘unexplained’ sterile ewes, that another gene was responsible. The present report concerns the available evidence concerning this hypothesis.

A 50K bovine DNA array allows large scale genotyping of dairy cattle for around 50 thousand markers (Single Nucleotide Polymorphisms -SNP). This development opens the door to genomic prediction and selection, and also facilitates gene detection, mapping and association studies. Any such application requires knowledge of the Linkage Disequilibrium (LD) state of the markers. The objective of this work was to examine the LD in two divergent genetic lines of dairy cows genotyped with the 50K bovine DNA array.

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.

Traditionally UK lamb finishers have used forage brassicas to extend the season of supply of lamb beyond the grazing season. Retailers however can now import low-cost chilled lamb from New Zealand from December to June so financially U.K. supply extension is now more risky. Here, two trials are described to i) evaluate the ability of currently used forage brassicas to finish lambs in Nov/Dec, and to ii) compare the most promising ones with mixtures containing chicory, plantain and clover for finishing lambs in August /Sept. The latter having shown to be bio-active with anthelmintic effects.

Consumer purchasing decisions are, to a large part, governed by the level and consistency of meat quality and there is a need to identify systems of production that deliver consistent lamb eating quality through the winter months that will restore retailer confidence in British lamb outside the main grazing season.. The Vipond et al. (2005) report on lamb eating quality highlighted the deterioration in lamb flavour post-Christmas and recommended that dietary effects be investigated with a specifically designed experiment.

Crossbreeding can be used in the hill sector to improve the efficiency of production. Carson et al. (2001) showed that ram breed substitution increased lamb output per ewe by 24% with concomitant improvements in carcass quality. However, information is required for a range of crossing sire breeds for the hill sector to enable the most effective crossbreeding programmes to be developed. Therefore, the primary aim of this study was to evaluate the effects of a range of lamb genotypes on lamb meat quality. Furthermore, a range of production systems (long-keep grass-based systems to short-keep concentrate-based systems) are used to finish hill lambs. Diet type (i.e. roughage-versus concentrate-based) can also affect lamb growth rates and carcass characteristics (Carson et al., 2001). Consequently, a secondary aim of this study was to evaluate the effects of diet and its interaction with lamb genotype on lamb meat quality.

The standard instrumental method for measurement of texture, Warner Bratzler shear force (WBSF), involves shearing six ‘good’ cores taken from a cooked sample of meat, with coring parallel to the fibre direction (AMSA, 1995), which is a time consuming and destructive methodology. A new, more rapid method, the slice shear force (SSF) test was developed which involves measuring the shear force of a single slice per sample (Shackelford et al 1999a). Shackelford et al. (1999b) reported that SSF was strongly correlated with sensory scores for 14d aged meat. The aim of the current investigation was to study the effect of sex differences on instrumental meat quality and to identify the relationship between SSF measured at 2 days and WBSF values measured at 14 and 21 days post slaughter.

The beef herd in the UK comprises of a diverse range in suckler cow genotypes and terminal sires (Keady et al., 2004a), which results in major variability in the animals presented for slaughter each day. Recent data indicates that Charolais and Limousin progeny account for over 65% of the beef animals slaughtered in Northern Ireland (APHIS, 2008). The objective of this study was to evaluate sire breed (Charolais or Limousin) and gender (steer or heifer) on performance during the finishing period, carcass parameters and meat quality.

With increasing consumer awareness of meat quality and the relationship between dietary fat and the incidence of diseases, such as coronary heart disease, research has been undertaken to manipulate fatty acid (FA) profiles in beef. Diet has been shown to influence FA composition of meat (Scollan et al, 2006). For example meat from finishing cattle offered red clover (legume) silage in comparison to grass silage had significantly increased polyunsaturated FA (PUFA) concentrations and a decreased n-6:n-3 ratio (3.28:2.30). The aim of this experiment was to assess the effect of offering lupins/triticale, vetch/barley and grass silage to continental beef finishing cattle on instrumental meat quality and FA composition.

Maize silage can be produced at a similar cost to grazed grass and is approximately 20% cheaper than grass silage (Keady et al., 2002). Recent studies have shown that maize silage inclusion in the diet increases the performance of dairy (Keady et al., 2003, 2008) and beef (Keady and Gordon, 2006, Keady et al., 2007) cattle and has a concentrate sparing effect of up to 2.5 kg and 5.0 kg, respectively (Keady, 2005). Previous studies at Athenry have shown that maize silage, regardless of maturity at harvest, results in similar levels of ewe and subsequent lamb performance relative to high feed-value grass silage, (Keady and Hanrahan, 2008, 2009). The objective of the current study was to evaluate the effects level and type of concentrate supplementation of maize silage diets on ewe and subsequent lamb performance.

Soya bean (Glycine max) meal is an important component of animal feed and oil seed rape and palm kernel cake and meal are typically used in commercial concentrate diets for sheep in the UK.. Lupins (Lupinus; Leguminosae) as a high protein, high energy, nitrogen-fixing grain legume, have potential as a home-grown livestock feed in the UK (Wilkins and Jones, 2000). Research has been conducted on the effects of narrow-leafed lupins (Lupinus angustifolius) (Hill, 2005) but there have been few studies on the effects of yellow lupins (Lupinus luteus) when fed to sheep. This study investigated the effects of incorporating either yellow lupins, narrow-leaf lupins or soya bean meal into the concentrate diets of finishing lambs on lamb productivity and carcass characteristics when compared to a commercial UK lamb finisher diet.

The oxidative stability of meat depends upon a combination of pro-and antioxidants and the degree of unsaturation of its lipid classes. When animals graze grass the concentrations of α-tocopherol and β-carotene in meat and fat increase and decrease when they are fed concentrates. Supplementation with α-tocopherol acetate increased αtocopherol concentration in the meat of concentrate-fed animals, less so for grass-grazed animals (Descalzo et al., 2005; Realini et al., 2004). Less is known about the relationship between diet, antioxidant enzymes systems such as Superoxide dismutase (SOD) and Catalase (CAT), and the oxidative stability of meat. This study aimed to determine the influence of a forage versus a concentrate diet fed to beef cattle, and an additional treatment with a PUFA-rich lucerne-based plant extract (PX), on the antioxidant profile of their meat, and its relationship with lipid oxidation and colour shelf life. The addition of PX raised the unsaturated nature of the beef muscle lipids and thus increased the oxidative stress (Kim et al., 2009).

Buffaloes (Bubalus bubalis) are an important component of livestock in Nepal. Its population has been estimated as 4,204,886 in 2005/06 (MOAC, 2006). Buffalo calves are seldom raised for meat in Nepal (Rana et al., 2000). In cases where they are raised, they are confined until six to eight months of age, as their dams will not give milk without them (Rana et al., 2000). Scientific information on fattening of male buffalo calves is scanty. A field based study was conducted to access the body weight of male buffalo calves raised under forage based and forage based plus limited concentrate supply at different ages, to determine the cost effectiveness of fattening technology under farmers’ managed condition.

The use of test day model (TDM) for genetic evaluation results in predicted transmitting abilities (PTAs) for any stage of lactation. However, in the United Kingdom (UK), publication and selection of parents are still based on PTAs computed on a 305-day basis from the random regression coefficients of the TDM. It is expected from selection index theory, that selection on 305-day PTAs would place different weights on PTAs at different days in milk (DIM). This could result in changes in the lactation curve of animals over time as a result of genetic progress. This study evaluates genetic trends in terms of changes in PTAs at different DIM for production traits and somatic cell counts (SCC) in the Holstein breed. In addition, the inclusion of SCC in the national profitable life index (£PLI) is based on its relationship with milk computed on a 305-day basis. This study also examines what impact such selection has on the relationship between PTAs for milk and SCC at different DIM.

Selection is the main tool used by animal breeders to improve the performance of their stock. Despite large gains being made at industry level in the major dairy traits (Royal et al, 2000) very few reports exist for the results of experiments on persistent selection for dairy traits in a single herd, particularly with reference to the correlated effects on other dairy traits. This paper reports one such set of results between 1980 and 2005 from SAC’s Langhill herd, which has been under maximal selection for milk production during this period.

Female fertility is an important component of a beef production system. In the British Limousin genetic evaluation there are several female fertility traits recorded (Coffey et al. 2007). Two of these traits are calving interval (CI) and age at first calf (AFC). In British beef breeds, Roughsedge et al. (2005) estimated moderate negative genetic correlations between CI and AFC; early maturing animals (low AFC) had longer CI because of genetic factors. However, it has also been suggested that management factors could be increasing the CI EBV of early maturing animals. For example, does the CI EBV account for heifer’s that calve early for the first calf, but then are not given the opportunity to re-mate when they first return to oestrus, and therefore, may have a longer raw CI record. There were two aims of this was work 1) to investigate if CI EBVs produced by the British Limousin genetic evaluation were affected by management decisions applied to early maturing animals (i.e. low AFC) and 2) to assess if reducing the season slice (i.e. reducing the chance of directly comparing early and late calvers) for the CI contemporary group (CG) improved the CI model.

Selective breeding of farm livestock is one of the most cost-effective ways of improving the performance and efficiency of livestock enterprises. Genetic improvement of British beef cattle over a ten year period was recently estimated to be worth approximately £23, and the benefits continue to rise (Amer et al., 2007). While these returns are impressive, they could be improved by increasing the rate of improvement in the purebred population, for example by increasing the relevance of estimated breeding values (EBVs) to beef production by using final carcass weight and grading information. This study will examine the feasibility carcass weights and classifications from UK commercial abattoirs for the genetic evaluation of cattle for carcass weight, carcass fatness class, and carcass conformation class.

In the UK, mean stillbirth rate is reported to be 6.7% (BPEX, 2008), which indicates a considerable loss for pig producers. Lately much research has been carried out to improve piglet survival by genetic improvement, but correlations between survival and reproduction traits showed contradictory results and seldom distinguished between maternal and direct piglet genetic effects. Some studies considered birth weight as a trait that is likely to be closely related to survival, but few looked at individual piglet birth weight. The aim of this study was to estimate genetic correlations between birth weight or its variation within litter and survival to examine if selection on individual birth weight is a viable way to improve survival.