EVALUATION OF CROSSBRED CALF AND COW TYPES; SUBJECTIVE TRAITS

Data in this experiment consisted of birth weight, calving score, thickness and grade records of 600 crossbred calves. Angus, Brangus, and Gelbvieh sires were mated to purebred Hereford cows. Yearling and 2-yr-old Angus-Hereford, Brangus-Hereford, and Gelbvieh-Hereford daughters then were bred to Polled Hereford bulls (Data Set 2). Later-parity Angus-Hereford, Brangus-Hereford, and Gelbvieh-Hereford daughters were mated to Salers or Simmental sires (Data Set 3). The traits evaluated were birth weight, thickness and feeder grade of calves and degree of calving diffi culty. Calving diffi culty, grade, muscling or thickness evaluation is a subjective assessment. Progeny of Angus cattle were lighter at birth and were born easier than progeny of Brangus and Gelbvieh cattle. Angus-Hereford cows were more likely to have medium grade calves than Brangus-Hereford cows (odds ratio=1.69) and that was the only signifi cant difference for grade in all data sets. Brangus calves had thicker muscles than Angus and Gelbvieh calves. Adding Bos Indicus genes to a cross may increase birth weight, calving diffi culty and muscle thickness

EVALUATION OF CROSSBRED CALF AND COW TYPES; SUBJECTIVE TRAITS

Data in this experiment consisted of birth weight, calving score, thickness and grade records of 600 crossbred calves. Angus, Brangus, and Gelbvieh sires were mated to purebred Hereford cows. Yearling and 2-yr-old Angus-Hereford, Brangus-Hereford, and Gelbvieh-Hereford daughters then were bred to Polled Hereford bulls (Data Set 2). Later-parity Angus-Hereford, Brangus-Hereford, and Gelbvieh-Hereford daughters were mated to Salers or Simmental sires (Data Set 3). The traits evaluated were birth weight, thickness and feeder grade of calves and degree of calving diffi culty. Calving diffi culty, grade, muscling or thickness evaluation is a subjective assessment. Progeny of Angus cattle were lighter at birth and were born easier than progeny of Brangus and Gelbvieh cattle. Angus-Hereford cows were more likely to have medium grade calves than Brangus-Hereford cows (odds ratio=1.69) and that was the only signifi cant difference for grade in all data sets. Brangus calves had thicker muscles than Angus and Gelbvieh calves. Adding Bos Indicus genes to a cross may increase birth weight, calving diffi culty and muscle thickness

Ranking of Sire Breeds and Beef Cross Breeding of Dairy and Beef Cows

End of Project ReportSummary There is general agreement across countries on the ranking of beef breeds for production and carcass traits. Differences between dairy and early maturing beef breeds in growth and slaughter traits are small, but the latter have lower feed intake and better carcass conformation. Late maturing beef breeds also have lower feed intake and better carcass conformation and in addition, have a higher growth rate, kill-out proportion and carcass muscle proportion. When factors such as age and fatness are accounted for, differences between breeds in meat quality traits are small. Differences amongst breed types in kill-out proportion can be explained by differences in gut contents (consequent on differences in feed intake), differences in the proportions of gastrointestinal tract and metabolic organs, differences in hide proportion, and differences in offal fats. Growth is an allometric, rather than an isometric, process. Some parts, organs and tissues grow relatively more slowly than the animal overall, and so become decreasing proportions over time, while others grow relatively faster and become increasing proportions. With increasing slaughter weight, the proportions of non carcass parts, hind quarter, bone, total muscle and higher value muscle decrease, while the proportions of non carcass and carcass fats, fore quarter and marbling fat all increase. Because of heterosis or hybrid vigour, the productivity of cross-bred cattle is superior to the mean of the parent breeds. While calving difficulty may be slightly higher (probably due to greater birth weight), calf mortality is much reduced in cross-breds. In addition, general robustness and growth rate are increased. There are additive effects of heterosis in the dam and the progeny. When cross-bred cows are mated to a bull of a third breed, >60 % of total heterosis is attributable to the cross-bred cows. The double muscling phenotype in beef cattle is due to the inactivated myostatin gene, but the inactivating mutation is not the same in all breeds and other genes also contribute to muscling. Compared to normal animals, double muscled animals have lower proportions of digestive tract, internal fats and metabolic organs. This explains their superior kill-out proportion. They also have a smaller hind shin that helps accentuate the muscling in the remainder of the 4 limb. There are similar degrees of muscular hypertrophy in both the hind and fore quarters. Muscle to bone ratio is about one third greater in double muscled than in normal carcasses. Piedmontese cattle with none, one or two mutated myostatin alleles were compared with normal Herefords and Limousins. In the absence of any mutated allele, Piedmontese were similar to Herefords, with one mutated allele they were similar to Limousins and with two mutated alleles they were immensely superior to Limousins. In fact, the response to the second mutated allele was about three times that to the first. If progeny approximated to the mean of the parent breeds, crossing a double muscled sire with a dairy or early maturing beef cow would result in cattle of similar characteristics to pure-bred late maturing beef breeds. This does not happen because double muscling is dependent on a homozygous myostatin genotype. The progeny of a common cow breed and normal late maturing, or double muscled, sire breeds have similar production traits

Relative Tissue Growth Patterns and Carcass Composition in Beef Cattle

End of Project ReportSummary The main objective of the beef breed evaluation programme carried out at Grange Beef Research Centre was to compare the productive characteristics of different beef breed crosses out of Holstein-Friesian cows. In the course of this work much additional information was acquired, particularly on growth patterns of body organs and tissues, and how these affect kill-out proportion and carcass composition. The data were also used to examine relationships between carcass classification variables and carcass composition. Cattle used for beef production in Ireland can be classified into three main biological types: (i) early maturing, (ii) dairy, and (iii) late maturing. Results from an experiment that compared Friesians (dairy), Hereford × Friesians (early maturing) and Charolais × Friesians (late maturing) are used to represent these biological types. The material is organized under the following headings: (i) non carcass parts and kill-out proportion, (ii) carcass composition, (iii) carcass tissue distribution, (iv) muscle chemical composition, (v) gender, (vi) dairy breeds, and (vii)carcass classification and composition. Kill-out proportion increased by about 10 g/kg from Friesians to Hereford × Friesians to Charolais × Friesians. It also increased by about 10 g/kg per 100 kg increase in slaughter weight. Friesians had higher proportions of gastrointestinal tract plus contents than the two beef crosses and also had higher proportions of metabolic organs. Hereford crosses had a higher proportion of hide and offal fats than Charolais crosses. At any carcass weight, early maturing animals had more fat and less bone and muscle than late maturing animals. As carcass weight increased, the proportions of bone and muscle in the carcass decreased, and the proportion of fat increased, but the rates of these changes differed with biological type. Carcass muscle distribution also differed with biological type. Late maturing cattle had a higher proportion of hind quarter and higher value muscle than Friesians and early maturing animals, while Friesians had higher proportions than early maturing animals. Muscle lipid content (marbling) differed with biological type (early maturing > dairy > late maturing) and with carcass joint (highest for flank and ribs, lowest for m. longissimus). Early maturing steers and heifers had similar carcass fat proportions when the heifers were about 60 kg carcass lighter than the steers. Despite having poorer carcass conformation, heifers had a slightly higher proportion of muscle and a considerably higher proportion of higher value muscle than steers. Carcass classification grade was not a reliable indicator of carcass muscle proportion. Carcass fat class was related to both carcass fat and muscle proportions but accounted for less than half the variance in these. Carcass conformation class was not related to carcass fat proportion, carcass muscle proportion or higher value muscle proportion, but it was negatively related to carcass bone proportion

Forage intake and digestibility of Angus, Hereford, and Hereford-Angus first-calving beef females grazing fescue-legume and fescue pastures

Forage intake and digestibility were measured from March 10 to September 15 for 80 lactating Angus, Hereford, and Hereford-Angus first-calf females. Females were fed Cr2O2 twice per day during this period, and an AM and PM fecal sample was collected for each female each week, and samples were composited. Fecal samples were analyzed for calcium, chromium, dry matter (DM), and crude fiber, and these components were used in a fecal index to calculate DM intake, DM digestibility, and digestible DM intake for each female each sampling time. Females grazing fescue-legume and fescue pastures had similar DM digestibility as an average (P \u3e .1). However, females on fescue-legume had significantly higher (P \u3c .0001) DM intakes and digestible DM intakes over the grazing season than did females on fescue pastures. The advantage for females on fescue-legume was primarily due to higher DM and digestible DM intakes during late spring and summer. However, females on the two pasture types consumed similar amounts of forage during the fall and early spring. A breed X pasture type interaction was detected for average DM digestibility for Hereford-Angus females. As an average of the season, Hereford-Angus on fescue-legume had higher DM digestibility, DM and digestible DM intake over Angus and Hereford on same pasture type, while Angus and Hereford females on fescue-legume had similar DM digestibilities, and DM and digestible DM intakes. Angus and Hereford females on fescue had similar digestibilities, DM, and digestible DM intake, while Hereford-Angus had higher DM and digestible DM intakes, however Hereford-Angus on fescue had the lowest digesti-bility of any breed on fescue. Over time, Hereford-Angus on fescue-legume had higher peaks during the late spring and stayed higher during late spring and summer for DM digestibility than Angus and Herefords on fescue-legume. However, Angus, Hereford, and Hereford-Angus on fescue-legume had similar patterns for DM and digestible DM intakes. Hereford-Angus on fescue had lower levels of digestibility during spring and summer than Angus and Herefords on fescue, but Hereford- Angus on fescue showed an increase for DM and digestible DM intake during the late summer and fall over Angus and Hereford females on fescue

Effect of Breed Group and Mating System on Weaning Production in Beef Cattle

Straightbred Hereford, Angus-Hereford and Simmental-Hereford are popular cow breeds in South Dakota. Larger and/or higher milking crossbreds can be expected to require more energy input to support higher maintenance and lactation requirements. Realizing this, comparisons between breed groups and mating systems under realistic conditions are of interest to producers. This study was designed to evaluate how straightbred Herefords along with Simmental-Hereford and Angus-Hereford two-breed rotations perform under western South Dakota range conditions. All cattle were maintained at the Antelope Range Livestock Station near Buffalo, South Dakota, throughout the study

Ohio Beef Cattle Production Testing Directory

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MITOCHONDRIAL DNA POLYMORPHISMS AND FERTILITY IN BEEF CATTLE

Two regions of mitochondrial DNA, D-loop and ND-5 were characterized using polymerase chain reaction – restriction fragment length polymorphism (PCR-RFLP) involving 422 beef cattle of Hereford and composite breeds from Wokalup’s research station. ANOVA models (model I, II) were used to estimate associations between molecular haplotypes and quantitative traits. The phenotypic data used were records on calving rate, defined as the mean number of live calves born over four years, while the genotypic data used were the result of PCR-RFLP analysis in both regions of mitochondrial DNA using 7 restriction enzymes. The results of the present study have provided evidence that mitochondrial polymorphisms in the D-loop and ND-5 regions are associated significantly with fertility. This is the first report of a correlation between mitochondrial polymorphism in D-loop and ND-5 on fertility in beef cattle. Key words: PCR-RFLP, bovine mitochondrial DNA, D-loop, ND-5

Rurality, Locality and Industrial Change: A Micro-scale Investigation of Manufacturing Growth in the District of Leominster

Geographers have recently sought to understand countryside change by examining economic restructuring and its impact on local social coherences. However, despite renewed interest in the locale, many investigations of the rural economy have been at a macro-scale. It is argued that this broad brush approach has neglected many important aspects of rural restructuring and, in particular, the importance of social and cultural constructions of change. This paper considers manufacturing growth in rural areas and focuses on western Hereford and Worcester. Based on the findings of a micro-scale investigation of a rural industrial estate, it examines the causes of manufacturing growth and assesses its impact on job creation, local restructuring and in-migration. Copyright © 1996 Elsevier Science Ltd

Epidermolysa bullosa in Danish Hereford calves is caused by a deletion in LAMC2 gene

BACKGROUND Heritable forms of epidermolysis bullosa (EB) constitute a heterogeneous group of skin disorders of genetic aetiology that are characterised by skin and mucous membrane blistering and ulceration in response to even minor trauma. Here we report the occurrence of EB in three Danish Hereford cattle from one herd. RESULTS Two of the animals were necropsied and showed oral mucosal blistering, skin ulcerations and partly loss of horn on the claws. Lesions were histologically characterized by subepidermal blisters and ulcers. Analysis of the family tree indicated that inbreeding and the transmission of a single recessive mutation from a common ancestor could be causative. We performed whole genome sequencing of one affected calf and searched all coding DNA variants. Thereby, we detected a homozygous 2.4 kb deletion encompassing the first exon of the LAMC2 gene, encoding for laminin gamma 2 protein. This loss of function mutation completely removes the start codon of this gene and is therefore predicted to be completely disruptive. The deletion co-segregates with the EB phenotype in the family and absent in normal cattle of various breeds. Verifying the homozygous private variants present in candidate genes allowed us to quickly identify the causative mutation and contribute to the final diagnosis of junctional EB in Hereford cattle. CONCLUSIONS Our investigation confirms the known role of laminin gamma 2 in EB aetiology and shows the importance of whole genome sequencing in the analysis of rare diseases in livestock