Explore the vast range of titles available.

Myostatin (GDF-8) is a member of the transforming growth factor β superfamily of secreted growth and differentiation factors that is essential for proper regulation of skeletal muscle mass in mice. Here we report the myostatin sequences of nine other vertebrate species and the identification of mutations in the coding sequence of bovine myostatin in two breeds of double-muscled cattle, Belgian Blue and Piedmontese, which are known to have an increase in muscle mass relative to conventional cattle. The Belgian Blue myostatin sequence contains an 11-nucleotide deletion in the third exon which causes a frameshift that eliminates virtually all of the mature, active region of the molecule. The Piedmontese myostatin sequence contains a missense mutation in exon 3, resulting in a substitution of tyrosine for an invariant cysteine in the mature region of the protein. The similarity in phenotypes of double-muscled cattle and myostatin null mice suggests that myostatin performs the same biological function in these two species and is a potentially useful target for genetic manipulation in other farm animals.

The aim of this study was to evaluate the prevalence of bovine tuberculosis (TB) and the magnitude and trend of tuberculous lesions in slaughtered cattle (1994 to 2010) as well as tuberculin skin tests (TST) in 2,853 cattle (84 herds) of 39 livestock rearing communities in the highlands of Cameroon. Out of 129,165 slaughtered cattle inspected, 599 (0.46%; 95% CI: 0.43%-0.50%) showed suspected tuberculous lesions among a total of 983 (0.76%; 95% CI: 0.71%-0.81%) identified pathologies. The monthly TB detection rates ranged from 0.30% (95% CI: 0.20%-0.40%) to 0.81% (95% CI: 0.64%-0.98%) and annual rates from 0.04% (95% CI: 0%-0.11%) to 1.46% (95% CI: 1.22%-1.69%). The rates were not affected by season and fluctuating peaks were also recorded. The comparative TST revealed that bovine TB was widely distributed in live cattle (4.67%; 95% CI: 3.89%-5.44%) and was significantly higher in the Western highlands than Adamawa plateaux. Comparative TST bovine TB reactors were higher (P less than 0.05) in cattle managed in semi-intensive and beef production systems compared to the others. Animals in small herds showed signif. higher rates than those in large herds. Bovine TB prevalence in exotic/upgraded cattle was comparable to that of the Red Bororo zebu but signif. higher than the rates in Guadali and White Fulani zebus. Among the indigenous zebus, the rate was signif. higher in Red Bororo than the Guadali and White Fulani. Sex did not influence bovine TB prevalence in this study but diagnosis of the disease was signif. higher among adult/older cattle than in younger animals. Further analysis of the TST responses revealed that atypical mycobacterial infections was widespread and 6.83% of tested animals showed positive reactions at both bovine and avian tuberculin injection sites and a strong association between skin responses to both tuberculins. Our study confirms that bovine TB is prevalent in live cattle and abattoirs in Cameroon.

The nature of domestic cattle origins in Africa are unclear as archaeological data are relatively sparse. The earliest domesticates were humpless, or Bos taurus, in morphology and may have shared a common origin with the ancestors of European cattle in the Near East. Alternatively, local strains of the wild ox, the aurochs, may have been adopted by peoples in either continent either before or after cultural influence from the Levant. This study examines mitochondrial DNA displacement loop sequence variation in 90 extant bovines drawn from Africa, Europe, and India. Phylogeny estimation and analysis of molecular variance verify that sequences cluster significantly into continental groups. The Indian Bos indicus samples are most markedly distinct from the others, which is indicative of a B. taurus nature for both European and African ancestors. When a calibration of sequence divergence is performed using comparisons with bison sequences and an estimate of 1 Myr since the Bison/Bos Leptobos common ancestor, estimates of 117-275,000 B.P. and 22-26,000 B.P. are obtained for the separation between Indians and others and between African and European ancestors, respectively. As cattle domestication is thought to have occurred approximately 10,000 B.P., these estimates suggest the domestication of genetically discrete aurochsen strains as the origins of each continental population. Additionally, patterns of variation that are indicative of population expansions (probably associated with the domestication process) are discernible in Africa and Europe. Notably, the genetic signatures of these expansions are clearly younger than the corresponding signature of African/European divergence.

Identification of individual major genes affecting quantitative traits in livestock species has been limited to date. By using a candidate gene approach and a divergent breed cross involving the Chinese Meishan pig, we have shown that a specific allele of the estrogen receptor (ER) locus is associated with increased litter size. Female pigs from synthetic lines with a 50% Meishan background that were homozygous for this beneficial allele produced 2.3 more pigs in first parities and 1.5 more pigs averaged over all parities than females from the same synthetic lines and homozygous for the undesirable allele. This beneficial ER allele was also found in pigs with Large White breed ancestory. Analysis of females with Large White breed background showed an advantage for females homozygous for the beneficial allele as compared to females homozygous for the other allele of more than 1 total pig born. Analyses of growth performance test records detected no significant unfavorable associations of the beneficial allele with growth and developmental traits. Mapping of the ER gene demonstrated that the closest known genes or markers were 3 centimorgans from ER. To our knowledge, one of these, superoxide dismutase gene (SOD2), was mapped for the first time in the pig. Analysis of ER and these linked markers indicated that ER is the best predictor of litter size differences. Introgression of the beneficial allele into commercial pig breeding lines, in which the allele was not present, and marker-assisted selection for the beneficial allele in lines with Meishan and Large White background have begun.

A total of 383 barrows and gilts from a French Large White experimental herd were slaughtered at 100 kg BW. Samples of longissimus muscle were taken to categorize myofibers according to their contractile (I, IIA, and IIB) and metabolic (oxidative and nonoxidative) properties. Myofiber percentages, cross-sectional areas (CSA), and relative areas were measured. Growth rate, carcass composition, muscle chemical composition, metabolic enzyme activities, and meat quality traits were also measured to estimate phenotypic and genetic correlations between these traits and myofiber characteristics. Genetic parameters were estimated using a REML procedure applied to an individual animal model. Heritabilities of fiber traits were moderate to high (h2 = .20 to .59). Highest heritabilities were found for type I fiber percentage (h2 = 46 +/- 11), type IIBw fiber percentage (h2 = .58 +/- .11), and type I fiber cross-sectional area (h2 = .59 +/- .10). For a given fiber type, the relative area was phenotypically and genetically more closely related to the percentage than to the CSA. Phenotypic correlations between fiber type composition and other traits were low. Genetically, growth rate, carcass leanness, and loin eye area were positively related to fiber CSA. Intramuscular fat content was not related to fiber type composition (rg = -.05 to .06), whereas it was positively related to fiber CSA (rg = .68). Type IIBw fiber percentage was related to pH at 30 min (rg = -.46), pH at 24 h (rg = -.62), glycolytic potential (rg = .31), and lightness of color (rg = .55) of longissimus muscle

The objective of this study was to investigate rumen fermentation, apparent digestibility of nutrients, and morphology of ruminal and intestinal mucosa in two cattle breeds of different metabolic type. Six purebred German Holstein (H) bulls representing the secretion type and six Charolais (CH) bulls representing the accretion type were fattened under identical conditions (from 9 to 18 months of age) with semi ad libitum feeding of a high energy diet. Body weight (668 vs. 764 kg, P = 0.011), body weight gain (1,223 vs. 1,385 g/day, P = 0.043), and body protein gain (93 vs. 128 g/day, P = 0.001) were lower in H than in CH bulls. Protein expense per kg protein accretion was higher in H bulls (13.8 vs. 10.2, P = 0.001). Compared to H, the villi of CH bulls were higher in duodenum (586 vs. 495 microm, P = 0.001) and proximal jejunum (598 vs. 518 microm, P less than 0.001), the crypt were deeper in duodenum (295 vs. 358 microm, P less than 0.001) and proximal jejunum (292 vs. 344 microm, P = 0.020). In contrast, the villi in ileum were higher in H than in CH animals (522 vs. 471 microm, P = 0.006). The weight of the small intestine (as percentage of total body weight) was 1.1 in H and 0.8 in CH bulls (P = 0.002). The utilization of crude protein was positively related to the duodenal (P = 0.001) and proximal jejunal villus height (P = 0.003) and to the duodenal crypt depth (P less than 0.001), and negatively related to the small intestine weight (P = 0.004). The higher growth potential and feed efficiency in CH bulls compared to H bulls is caused by differences in size of small intestine and morphology of small intestinal mucosa. Obviously the duodenum and proximal jejunum of CH bulls adapt to increase the absorptive surface due to the increase in nutrient demand.

The noncoding control region of the mitochondrial DNA of various gallinaceous birds was studied with regard to its restriction fragment length polymorphism (RFLP) and sequences of the first 400 bases. Tandem duplication of the 60-base unit was established as a trait unique to the genus Gallus, which is shared neither by pheasants nor by quails. Unlike its close ally Gallus varius (green junglefowl), the red junglefowl Gallus gallus is a genetically very diverse species; the 7.0% sequence divergence was seen between those from Thailand (G. g. gallus and G. g. spadiceus) and the other from the Indonesian island of Java (G. g. Bankiva). Furthermore, the divergence increased to 27.83% if each transversion is regarded as an equivalent of 10 transitions. On the other hand, a mere 0.5-3.0% difference (all transitions) separated various domestic breeds of the chicken from two G. g. gallus of Thailand, thus indicating a single domestication event in the area inhabited by this subspecies of the red junglefowl as the origin of all domestic breeds. Only transitions separated six diverse domesticated breeds. Nevertheless, a 2.75% difference was seen between RFLP type I breeds (White Leghorn and Nagoya) and a RFLP type VIII breed (Ayam Pelung). The above data suggested that although the mitochondrion of RFLP type V was the main contributor to domestication, hens of other RFLP types also contributed to this event.

We tested whether pronounced morphological variability of horses caused by artificial selection was followed also by variation in their vocalization. We compared whinnies of 10 breeds representing horse varieties both in morphology and history using discrimination analyses (Wilks´ lambda = 0.070). Whinnies of Shetland pony were the most distinct from calls of other breeds (74.1% classification success). This result is in agreement with distinction based on morphological features. Whinnies of the primitive Hucul horse belonged among the most correctly classified ones (73.5%). Classification results of both Old Kladruby horse colour forms were very different: whinnies of the grey form revealed the least successful classification (18.9%) whilst calls of the black form showed one of the best classification outputs (72.4%). A surprising result was the extreme vocal distinction between the heaviest breeds, confirmed by discrimination analysis, the Czech-Moravian Belgian (55.5%), and Silesian Noriker (51.4%). This finding was contrary to their morphological similarity. The relationship between morphological and acoustical variables revealed a significant correlation. Our results did not confirm the hypothesis of acoustic distinction in horse breeds based simply on their morphology. However, whinnies of an old breed, the Shetland pony, were the most distinct ones from all the others. The other old breeds, the Thoroughbred and the Old Kladruby horses, clustered together with the modern Czech warmblood. Our results seem to not confirm the second hypothesis of vocal distinction based on the length of time since establishment of the respective breed. Significant differences among horse breeds indicate the process of vocal distinction during the process of artificial selection.

Twelve Chinese indigenous goat populations were genotyped for twenty-six microsatellite markers recommended by the EU Sheep and Goat Biodiversity Project. A total of 452 goats were tested. Seventeen of the 26 microsatellite markers used in this analysis had four or more alleles. The mean expected heterozygosity and the mean observed heterozygosity for the population varied from 0.611 to 0.784 and 0.602 to 0.783 respectively. The mean FST (0.105) demonstrated that about 89.5% of the total genetic variation was due to the genetic differentiation within each population. A phylogenetic tree based on the Nei (1978) standard genetic distance displayed a remarkable degree of consistency with their different geographical origins and their presumed migration throughout China. The correspondence analysis did not only distinguish population groups, but also confirmed the above results, classifying the important populations contributing to diversity. Additionally, some specific alleles were shown to be important in the construction of the population structure. The study analyzed the recent origins of these populations and contributed to the knowledge and genetic characterization of Chinese indigenous goat populations. In addition, the seventeen microsatellites recommended by the EU Sheep and Goat Biodiversity Project proved to be useful for the biodiversity studies in goat breeds.