Mature Body Size Research Articles

Breed Preference by Farmers and the Morphometric Characteristics of Sukuma Goats and a Crossbred of Malya and Sukuma Goats in Maswa District, Tanzania

Aims: To study farmers’ perception toward performance of crossbreds (Malya x Sukuma) relative to the indigenous Sukuma goats.
 Study Design: The study was of cross-sectional design employing comparative analysis.
 Place and Duration of Study: The study was conducted in Maswa District of Tanzania over a three weeks period.
 Methodology: Fifty respondents from household which were previously involved in the crossbreeding program were sampled purposively. In which they were interviewed using questionnaires on good/positive and bad/negative attributes for each genotype, then ranks of desired breed according to market price, mature body size and age of attaining mature size. Body weights and linear body measurement of mature crossbred (Malya x Sukuma) goats and pure Sukuma goats were also taken after interviewing each household respondent. Interview data were analyzed using descriptive statistics option of SPSS and body measurements were analyzed using GLM procedure of SAS.
 Results: The most preferred breed was crossbred goats due to their high market price, large mature body size and early age of attaining mature size. Good attributes for Sukuma goats were disease resistance (98%) and drought resistance (94%) while bad attributes were low price in the market (88%), small body size (94%) and slow growth rate (72%). Good attributes for crossbred goats were premium price in the market (92%), high growth rate (80%) and large body size (94%). Bad attributes for crossbred goats had very low frequency. The crossbred goats were larger compared to Sukuma goats. Their mature body measurements were body length (60.6±0.46 cm), heart girth (77.6±0.58 cm), height at withers (66.4±0.42 cm) and body weight (35.1±0.52 kg) for crossbred goats while corresponding mature body measurements for Sukuma goats were 49.6±0.42 cm, 65.1±0.54 cm, 56.7±0.39 cm and 21.6±0.48 kg, respectively.
 Conclusion: Crossbred goats were accepted by farmers due to their beneficial impact to the households’ economy.

Fish weight reduction in response to intra‐ and interspecies competition under climate change

AbstractAs described by the temperature–size rule paradigm, fish living in warmer temperatures grow faster but have a smaller mature body size. However, the changes in the body size of fish communities in the western North Pacific, which is one of the most active fishing grounds, remain unclear. This study aimed to investigate changes in the body size of fish assemblages in the western North Pacific and whether fish sizes were potentially driven by the temperature–size rule, bottom‐up effects and intra‐ and interspecies competition at a community scale. We evaluated the fish weight data of 6 stocks of 4 species from 1978 to 2018 and 17 stocks of 13 species from 1995/1997 to 2018. Weight reduction in the fish assemblage was observed in the 1980s and was associated with the biomass peak of the Japanese sardine (Sardinops melanostictus), indicating the effect of intra‐ and interspecies competition. Another weight reduction was observed in the 2010s, which was associated with a moderate increase in the biomass of the Japanese sardine and chub mackerel (Scomber japonicus). Our analyses indicate that stronger stratifications in the surface layers during the 2010s potentially reduced the nutrient supply from the subsurface to the surface layers. This limitation in food availability forced intra‐ and interspecies competition under a moderate increase in fish biomass. Our findings underscore the critical significance of integrating the impacts of species competition and climate change on fish sizes to improve fishery management at a community level.

Association of ovine follistatin gene polymorphisms with body measurements, fat-tail traits and morphometric of head in Iranian Mehraban sheep

The mature body size of sheep is a polygenic trait that is used as a main selection criterion for increasing meat production through genetic selection. The purpose of this study was to characterize polymorphisms of the follistatin gene (FST locus), which is known to regulate muscle hypertrophy by inhibiting both myostatin and activin. Using single-strand conformation polymorphism analysis (SSCP) and Sanger sequencing, we examined polymorphisms of the ovine FST gene (OAR_v.3.1; Chr 16, NC_019473.1) in Iranian Mehraban sheep (n = 100, seven-month-old male lambs) with records of body measurements, fat-tails, and head morphometry. Among the nine SSCP patterns A to I, we identified five single nucleotide polymorphisms (SNPs), including g.25632659 G>C, g.25632701 G>A, g.25633069 A>G, g.25633069 A>T, and g.25634085 G>C. The only amino acid-altering variant was g.25632659 G>C in exon 3 (p.216Thr > Ser). According to a subsequent statistical analysis, SSCP patterns A (g.25632659 G/C, g.25632701 G/G), B (g.25632659 C/C, g.25632701 G/A), C (g.25632659 C/C, g.25632701 A/A), D (homozygous reference; g.25633069 A/A), E (heterozygous; g.25633069 A/G) and F (homozygous variant; g.25633069 T/T) were significantly (P < 0.05) connected with body measurements. Furthermore, patterns A and B had significantly (P ≤ 0.05) longer forehead lengths than the lambs with the pattern C. Pattern I (homozygous variant; g.25634085 C/C) was significantly associated with an increased mouth width, and decreased eye length compared to patterns H (heterozygous; g.25634085 G/C) and G (homozygous reference; g.25634085 G/G). The findings of this study provide primary evidence of linking between the polymorphisms of the FST gene and body size in a small panel of Iranian Mehraban sheep population.

PSI-B-28 Breed effect on weight gain of broilers

Abstract Poultry production as an aspect of livestock production is important to the biological needs, economic and social development of the people in any nation. Broiler birds are specifically bred for rapid growth to attain mature body size within 7–10 weeks depending on the strain, sex and management. This study was carried out in the humid tropics of Southwestern Nigeria. The experimental units were derived from four commercial broiler breeds namely Arbor Acre, Cobb, Marshall and Ross. Each breed had 76 chicks totaling 304 across the four breeds. On arrival, each chick was tagged by breed and identification number, and the initial weight of the chicks were recorded. Each of the breeds were thereafter randomly selected and randomly assigned to four experimental plots as replicates of the same treatment. The broiler birds were reared for 10 weeks and their weight taken and recorded at weekly intervals. All statistical analyses were conducted using boxplot, descriptive statistic and general linear models of Minitab® 16. After exploratory analysis to check for normality and outliers, a total of 217 birds were used in the final analyses. Except for the Marshall breed that had a highly significantly (P &amp;lt; 0.01) lower weight at hatching, other breeds had fairly similar weight (Table 1). However, there was no statistical (P &amp;gt; 0.05) difference in mean initial weight across the four replicates. While breed alone accounted for 37.81% of the total variation in initial weight, it only accounted for 30.07% of the difference in weight gain. The effect of breed on weight gain was only significant (P &amp;lt; 0.01) in Marshall, while the other three breeds were not statistically different (P &amp;gt;0.05). It can be deduced from this study that performance in terms of weight gain of most of the commercially available breeds in Nigeria are similar with the exception of Marshall.

All sheeps and sizes: a genetic investigation of mature body size across sheep breeds reveals a polygenic nature.

SummaryMature body size is genetically correlated with growth rate, an important economic trait in the sheep industry. Mature body size has been studied extensively in humans as well as cattle and other domestic animal populations but not in sheep. Six‐hundred and sixteen ewes, across 22 breeds, were measured for 28 linear measurements representing various skeletal parts. PCA from these measures generated principal components 1 and 2 which represented 66 and 7% of the phenotypic variation respectively. Two‐hundred and twenty sheep were genotyped on the Illumina Ovine HD beadchip for a GWAS investigating mature body size and linear body measurements. Forty‐six (Bonferroni P < 0.05) SNP associations across 14 chromosomes were identified utilizing principal component 1, representing overall body size, revealing mature body size to have fewer loci of large effect than other domestic species such as dogs and horses. Genome‐wide associations for individual linear measures identified major quantitative trait loci for withers height and ear length. Withers height was associated (Bonferroni P < 0.05) with 12 SNPs across six chromosomes whereas ear length was associated with a single locus on chromosome 3, containing MSRB3. This analysis identified several loci known to be associated with mature body size in other species such as NCAPG, LCORL, and HMGA2. Mature body size is more polygenic in sheep than other domesticated species, making the development of genomic selection for the trait the most efficient option for maintaining or reducing mature body size in sheep.

Natural history of Xenodon matogrossensis (Scrocchi and Cruz, 1993) (Serpentes, Dipsadidae) in the Brazilian Pantanal

Xenodon mattogrossensis is a neotropical snake restricted to the central part of South America, in the Pantanal wetlands and a few neighbouring areas. The available information about this specie in the literature is restricted to geographical distribution, morphological variation and anecdotal information on habitat use. Here we present data on diet, sexual dimorphism and reproduction of X. matogrossensis . We gathered information on diet and reproduction from 72 specimens of X. matogrossensis deposited in scientific collections. This species feeds mainly on amphibians, but also consumes squamate eggs and other small vertebrates. Mature females are generally bigger than mature males considering body size and head width, but males have longer tail than females. The number of follicles and eggs is not related with body size in females of X. matogrossensis . Females showed larger follicle sizes from October to April, suggesting that reproduction is seasonal, even though individuals may be active through the year. The information provided here, associated with others available in the literature can contribute to the assessment of the conservation status of this species and even to design conservation actions in case they are needed in the future.

From zygote to a multicellular soma: Body size affects optimal growth strategies under cancer risk

AbstractMulticellularity evolved independently in multiple lineages, yielding organisms with a wide range of adult sizes. Building an intact soma is not a trivial task, when dividing cells accumulate damage. Here, we study “ontogenetic management strategies,” that is rules of dividing, differentiating and killing somatic cells, to examine two questions: first, do these rules evolve differently for organisms differing in the target mature body size, and second, how well a strategy evolved in small‐bodied organisms performs if implemented in a large body—and vice versa (“large”‐evolved strategies in small bodies). We model the growth and mature lifespan of an organism starting from a single cell and optimize, using a genetic algorithm, trait combinations across a range of target sizes, with seven evolving traits: (a) probability of asymmetric division, (b) probability of differentiation (per symmetric cell division), (c) Hayflick limit, (d) damage response threshold, (e) damage response strength, (f) number of differentiation steps and (g) division propensity of cells relative to “stemness.” Some but not all traits evolve differently depending on body size: large‐bodied organisms perform best with a smaller probability of differentiation, a larger number of differentiation steps on the way to form a tissue and a higher threshold of cellular damage to trigger cell death, than small organisms. Strategies evolved in large organisms are more robust: they maintain high performance across a wide range of body sizes, while those that evolved in smaller organisms fail when attempting to create a large body. This highlights an asymmetry: under various risks of developmental failure and cancer, it is easier for a lineage to become miniaturized (should selection otherwise favour this) than to increase in size.

Secular Dynamics of Body Height and Weight in Russian Children Aged 0–17

This study deals with long-term temporal changes of body height and weight during various stages of ontogeny: newborns, infancy, early age, fi rst childhood, second childhood, adolescence, and youth. Each age/sex group numbers ca 100 persons, the total sample size is ca 2 000. The meta-analysis is based primarily on growth standards for Russian children, regularly renewed by the Research Institute for the Hygiene and Health Protection of Children and Adolescents and mostly relating to separate decades of the 20th century. The intensity of the secular trends was assessed through the analysis of scatter plots. The largest share in the secular increase of bodily dimensions belongs to intense growth during the second year of life and during the adolescent growth spurt. The smallest share is that of intrauterine growth, limited by the mother’s body size, and that of growth during adolescence, when the mature body size has been virtually reached and growth rate is minimal. Boys, who are more eco-sensitive, demonstrate greater secular changes than girls, who are eco-resistant. Smaller secular changes in weight than in height in both boys and girls result in the increase of leptosomy. This heterochrony concerns mostly newborns, whose body mass is a standard example of stabilizing selection.

Ten Cases of Divergence in the Seedling Ecology of Dudleya (Crassulaceae)

Dudleya is a genus of succulents consisting of 49 terminal taxa. Many are restricted to narrow geographic ranges with closely related forms living in differing climates. Previously, we found an intriguing set of correlations among nine more or less sympatric Dudleya: species with a smaller mature body size had a lower tolerance for an arid inland climate compared to larger bodied species. Thus, we were motivated to test for rules caused by convergent evolution. We sampled 20 populations from locations across much of the range of the genus. The 20 populations were placed into 10 pairs of close relatives. For each pair, one form was judged to be more mesophilic and the other to be more xerophilic, based on climate-of-origin. We measured germination rate, survival through the summer drought in a coastal garden, and survival through the summer in an inland garden. We hypothesized (among other things) that the xerophilic taxa would have larger mature body sizes and greater rates of survival than mesophilic relatives; however, this and other expected patterns were not repeated across the 10 pairs. Members of pairs have diverged both in various morphological traits and in seedling ecology, but evolution has seemingly not converged on rules. For nearly all taxa, habitat dependence was clear, i.e. plants survived significantly better through the summer at the coastal garden than at the inland garden. Quite possibly the correlations we previously found were caused by divergence between particular lineages coupled with phylogenetic conservatism. Considering the 10 pairs, Dudleya divergences appear to each evolve individualistically.

A multi‐ingredient athletic supplement disproportionately enhances hind leg musculature, jumping performance, and spontaneous locomotion in crickets (Acheta domesticus)

AbstractNutrition is a key component of life‐history theory with profound impacts on fitness traits. We examined lifetime impacts of a multi‐ingredient athletic supplement (MAS) on physical performance, anatomical morphology, survivorship, and general life‐history features in the house cricket, Acheta domesticus (L.) (Orthoptera: Gryllidae). The MAS was formulated using 13 nutraceutical supplements that are commonly used by human athletes specifically to improve athletic performance. Cricket doses were based on human doses adjusted for body size and metabolic rate. Markers of athletic performance included: jumping distance, spontaneous locomotor activity, and morphology of the hind legs (femurs). Supplemented adult crickets jumped ca. 25% further and expressed elevated spontaneous locomotion relative to controls. The MAS disproportionately increased hind leg femur length and width. Life‐history endpoints included survivorship, juvenile growth rate, maturation age, and mature body size. Supplemented crickets showed faster juvenile growth and earlier maturation, but no change in final adult size. A 20% increase in mean survivorship (extending into older ages) was also documented. Crickets represent an excellent new model for assessing athletic diets and associated performance criteria. Finally, as experimental animals were untrained, we argue that our supplement may represent a novel ‘exercise mimetic’ that impacts both performance and survivorship.

Effect of mature body weight and stocking rate on cow and calf performance, cow herd efficiency, and economics in the southeastern United States.

Eight 4-ha mixed warm-season grass pastures in southwestern Arkansas (33°40'4″ N, 93°35'24″ W, and elevation 107 m) were stocked with either large mature size (571 kg [SD 55.2] BW) or small mature size (463 kg [SD 58.2] BW) spring-calving cows at 4 stocking rates (SR; 1, 1.5, 2, or 2.5 cow-calf pairs/ha) over 4 yr to test the effects of SR and mature body size on cow and calf performance and system economics. Each pasture received 112 kg/ha N as ammonium nitrate in May and was broadcast seeded to annual ryegrass ( Lam.) in mid October each fall along with 112 kg/ha N as ammonium nitrate. Data were analyzed by regression to determine the effects of cow size and SR on calf performance, cow BW change, calf gain, weaning weight per hectare, hay feeding requirements, and net returns. As SR increased, cow BW and BCS at weaning decreased ( < 0.01) by 26 kg and 0.36 condition scores, respectively, for each additional cow stocked per hectare ( = 0.44). Calf BW at weaning in October increased ( < 0.01) 19 kg for each 100-kg increase in cow BW but was not affected ( = 0.66) by SR. As cow BW increased, calf BW at weaning per 100 kg cow BW decreased ( < 0.01) 6.7 kg for each 100-kg increase in cow BW but was not affected ( = 0.44) by SR. Neither cow BW nor SR affected ( ≥ 0.53) pregnancy percentage, which averaged 88% over the 4-yr experiment. Calf BW weaned per hectare was not affected ( = 0.75) by cow BW but linearly increased ( < 0.01) by 217 kg for each additional cow per hectare SR. Hay feeding days and cost of hay per cow increased ( ≤ 0.05) and kilograms of hay offered per cow tended ( = 0.09) to linearly increase with increasing SR, yet cow BW had no effects ( > 0.22). Although there were no effects ( ≥ 0.38) of cow BW on carrying cost or net returns, increasing SR decreased ( < 0.01) total expenses by US$102/cow and increased net returns by $70/cow and $438/ha for each cow per hectare increase in SR. These data indicate that increasing cow size can increase weaning BW of calves but does not affect total production per hectare or profitability, even though weaning weight efficiency ratios were reduced. Increasing SR reduced cow BW and BCS at weaning and increased feeding of conserved forages but did not affect pregnancy rates and led to increases in total calf BW weaned per hectare and net returns.

Direct and maternal components of variance for relative growth rate in Nilagiri and Sandyno sheep

A study was conducted to estimate genetic parameters of relative growth rate (RGR) and explore the possibility of its use as a selection criterion in Nilagiri and Sandyno sheep. RGR for the pre-weaning (birth to 3 months, n=6504) and post-weaning (3–6, 6–9, 9–12 and 3–12 months, n=4309, 3267, 2978 and 3257, respectively) periods were studied. The maximum RGR was noticed for the pre-weaning period and least during the latest age interval from 9 to 12 months. The ability of the trait to adjust for body size was evident from the effects of litter size, breed and age of dam on the trait. An animal model, including maternal effects was used to obtain REML estimates of (co)variances. Maternal genetic effects and inbreeding were not significant for RGR at any of the age intervals. Moderate estimates of heritability were obtained for pre-weaning RGR, with values of 0.126 and 0.103 for Nilagiri and Sandyno sheep, respectively. Among the post-weaning RGR, the age interval 3–6 months showed moderate value (0.140) in Nilagiri sheep. Post-weaning RGR for other intervals in Nilagiri and all intervals in Sandyno sheep showed negligible to low heritability estimates. The genetic correlations between pre-weaning RGR and body weight traits were high and positive in Nilagiri sheep. The estimates for the breed were found to decrease with age. Moderate heritability for pre-weaning RGR and high genetic correlation of the trait with other body weight traits provide scope for indirect selection using the trait in Nilagiri sheep. The result of the study supports the fact that RGR is able to adjust growth curve in such a way as to improve growth without affecting mature body size.

Impacts of metformin and aspirin on life history features and longevity of crickets: trade-offs versus cost-free life extension?

We examined the impacts of aspirin and metformin on the life history of the cricket Acheta domesticus (growth rate, maturation time, mature body size, survivorship, and maximal longevity). Both drugs significantly increased survivorship and maximal life span. Maximal longevity was 136 days for controls, 188 days (138 % of controls) for metformin, and 194 days (143 % of controls) for aspirin. Metformin and aspirin in combination extended longevity to a lesser degree (163 days, 120 % of controls). Increases in general survivorship were even more pronounced, with low-dose aspirin yielding mean longevity 234 % of controls (i.e., health span). Metformin strongly reduced growth rates of both genders (<60 % of controls), whereas aspirin only slightly reduced the growth rate of females and slightly increased that of males. Both drugs delayed maturation age relative to controls, but metformin had a much greater impact (>140 % of controls) than aspirin (~118 % of controls). Crickets maturing on low aspirin showed no evidence of a trade-off between maturation mass and life extension. Remarkably, by 100 days of age, aspirin-treated females were significantly larger than controls (largely reflecting egg complement). Unlike the reigning dietary restriction paradigm, low aspirin conformed to a paradigm of "eat more, live longer." In contrast, metformin-treated females were only ~67 % of the mass of controls. Our results suggest that hormetic agents like metformin may derive significant trade-offs with life extension, whereas health and longevity benefits may be obtained with less cost by agents like aspirin that regulate geroprotective pathways.

Determination of Akbash Shepherd Dog raised in Turkey

This study was carried out to determine the body measurements of the Turkish Akbash Shepherd Dogs raised in provinces of Afyon, Ankara, Eskisehir and Manisa by comparing with some other dog breeds of Turkey by minding factors of sex, region and age. For this purpose, a total of 59 (34 male and 25 female) dogs was included in the study and the data were statistically analysed. Descriptive statistics and comparison results for live weight 44.9±0.80 kg, and height at shoulders 75.3±0.59, height at rump 74.2±0.64, body length 81.8±1.00, heart girth circumference 86.5±0.81, chest width 32.6±0.33, and cannon circumference 13.3±0.13 cm respectively. The overall results of the study showed that Turkish Akbash Shepherd dogs had a very close resemblance to the Turkish Kangal (Karabash) and Kars (Caucasian) Shepherd dogs related with body measurements. The Akbash Shepherd dogs reach mature body weight and size at around 2 years of age. The current study also demonstrated that the Turkish Akbash Shepherd dogs raised in provinces of Afyon and Manisa are smaller than dogs raised in Ankara and Eskisehir.

From spiderling to senescence: ontogeny of color in the jumping spider,Habronattus pyrrithrix

The diverse colors of animals serve a variety of purposes, from acquiring mates to avoiding predators. Often, color patterns are not static throughout life, but change drastically during development, maturity, and senescence. While recent work has focused on the signaling value of vibrant colors in jumping spiders (Salticidae), we know very little about how colors change as spiders age; such information can provide a context for understanding the functions of and constraints on colorful traits. Focusing on Habronattus pyrrithrix Chamberlin 1924, our goals were to examine (1) the microscopic morphology of the colored body regions that males display to females during courtship (i.e., males' red faces, green legs, and white pedipalps), (2) how the colors of these regions as well as dorsal color patterns change during development prior to sexual maturity, and (3) how male condition-dependent red facial and green leg coloration changes as males age beyond sexual maturity. Although the bright white pedipalps and green legs of males appeared only upon sexual maturity, the sexes began to differentiate in facial coloration and dorsal patterning, with males developing red faces and conspicuous black and white dorsal patterning as young juveniles (ca. 2.5 mm in body length, or ca. 45% of their total mature adult body size). Even after maturity, color was not static; a male's green legs (but not red face) faded with age. Results are discussed in the context of potential functions of and constraints on color in salticids, and how they may change throughout an individual's lifetime.

Hatching response to temperature along a latitudinal gradient by the fairy shrimp Branchinecta lindahli (Crustacea; Branchiopoda; Anostraca) in culture conditions

Branchinecta lindahli is a broadly distributed fairy shrimp, reported from a range of temporary wetland habitat types in arid western North America. This species’ eggs hatch after the habitat dries, refills from seasonal rain, and receives a strong cold shock during the winter low temperatures. I studied phenotypic variation in temperature responses in cultures collected from four populations across 8° of latitude with low average temperatures ranging from -8 to 8°C. Time to maturation, mature body size and first clutch size decreased, as temperature increased, with only minor body size variability at mortality, regardless of culture origin. No variation in individual egg size was observed, demonstrating that body size is sacrificed to produce at least a few normal eggs during unfavourable years. Latitudinal variation in hatching temperature demonstrated a pattern of adaptive significance, with some overlap between regional temperature hatching cues. Phenotypic hatching temperature and growth rate responses may cause genetic segregation, selecting one cohort for warmer, dryer years and one cohort for cooler, wetter years. Drier year selected cohorts can exploit habitats that have shorter hydroperiods even in wet years. This may lead to population specialisation and speciation by adapting to more extreme habitats

Analysis of genetic correlations of hip height with selection indices and mature weight in Nelore cattle

Body size is directly related to the productive and reproductive performance of beef cattle raised under free-range conditions. In an attempt to better plan selection criteria, avoiding extremes in body size, this study estimated the heritabilities and genetic correlations of yearling hip height (YH) and mature hip height (MH) with selection indices obtained at weaning (WI) and yearling (YI) and mature weight (MW). Data from 102,373 Nelore animals born between 1984 and 2010, which belong to 263 farms that participate in genetic evaluation programmes of beef cattle conducted in Brazil and Paraguay, were used. The (co)variance components and genetic parameters were estimated by Bayesian inference in multi-trait analysis using an animal model. The mean heritabilities for YH, MH and MW were 0.56 ± 0.06, 0.47 ± 0.02 and 0.42 ± 0.02, respectively. The genetic correlation of YH with WI (0.13 ± 0.01) and YI (0.11 ± 0.01) was practically zero, whereas a higher correlation was observed with MW (0.22 ± 0.03). Positive genetic correlations of medium magnitude were estimated between MH and WI and YI (0.23 ± 0.01 and 0.43 ± 0.02, respectively). On the other hand, a high genetic correlation (0.68 ± 0.03) was observed between the indicator traits of mature body size (MH and MW). Considering the top 20 % of sire (896 sires) in terms of breeding values for the yearling index, the rank sire correlations between breeding values for MH and MW was 0.62. In general, the results indicate that selection based on WI and YI should not lead to important changes in YH. However, an undesired correlated response in mature cow height is expected, particularly when selection is performed using YI. Therefore, changes in the body structure of Nelore females can be obtained when MH and MW is used as a selection criterion for cows.

Transcript profiling of expressed sequence tags from semimembranosus muscle of commercial and naturalized pig breeds

In general, genetic differences across different breeds of pig lead to variation in mature body size and slaughter age. The Commercial breeds Duroc and Large White and the local Brazilian breed Piau are ostensibly distinct in terms of growth and muscularity, commercial breeds are much leaner while local breeds grow much slower and are fat type pigs. However, the genetic factors that underlie such distinctions remain unclear. We used expressed sequence tags (ESTs) to characterize and compare transcript profiles in the semimembranosus muscle of these pig breeds. Our aim was to identify differences in breed-related gene expression that might influence growth performance and meat quality. We constructed three non-normalized cDNA libraries from semimembranosus muscle, using two samples from each one, of these three breeds; 6902 high-quality ESTs were obtained. Cluster analysis was performed and these sequences were clustered into 3670 unique sequences; 24.7% of the sequences were categorized as contigs and 75.3% of the sequences were singletons. Based on homology searches against the SwissProt protein database, we were able to assign a putative protein identity to only 1050 unique sequences. Among these, 58.5% were full-length protein sequences and 17.2% were pig-specific sequences. Muscle structural and cytoskeletal proteins, such as actin, and myosin, were the most abundant transcripts (16.7%) followed by those related to mitochondrial function (12.9%), and ribosomal proteins (12.4%). Furthermore, ESTs generated in this study provide a rich source for identification of novel genes and for the comparative analysis of gene expression patterns in divergent pig breeds.

Partial Resolution of Hypoplastic Trachea in Six English Bulldog Puppies with Bronchopneumonia

Six English bulldog and nine nonbrachycephalic puppies with bronchopneumonia and radiographs were evaluated. Relative size of the trachea was measured by the tracheal diameter (TD) and the thoracic inlet distance (TI), expressed as a ratio (TD:TI). At diagnosis of bronchopneumonia, there was a significant difference between the median TD:TI of the bulldog puppies (0.07; range, 0.06-0.09) and that of the nonbrachycephalic puppies (0.14; range, 0.11-0.25; P=0.0004). At the same time, there was also a significant difference between the mean TD:TI of bulldog puppies (0.07±0.01) and that of nonbrachycephalic puppies (0.15±0.05; P=0.002). Follow-up radiographs showed significant increases in TD:TI ratio in all six bulldogs (median TD:TI = 0.14; range, 0.12-0.18; P=0.03 and mean TD:TI = 0.15±0.02; P=0.0007), whereas the ratio did not change significantly in the nonbrachycephalic control group (median TD:TI = 0.17; range, 0.14-0.22; P=0.10 and mean TD:TI = 0.18±0.03; P=0.06). Tracheal hypoplasia in some brachycephalic dogs might partially or completely resolve with growth to mature body size.

Hormonal growth promotant use in the Australian beef industry

This review focuses on the science that underpins the use of hormonal growth promotants by Australian beef producers. Their effect on increased liveweight gain is reliable and they are used in the grass-fed industry to produce heavier carcasses suitable for the liveweight and age specifications on high value markets. With implants containing only oestradiol, the growth rate response varies between 0.05 and 0.1 kg/day, dependent on the digestible energy intake and the duration of the implant’s functional life for which the animal is in positive energy balance. Combination implants containing both oestradiol and trenbolone acetate promote greater responses in liveweight gain, which can be as high as 0.2 kg/day on good quality pasture. Although there is also accelerated liveweight gain on energy-dense feedlot diets, the main commercial benefit is reduced feed costs associated with improvements in feed conversion efficiency. An example given demonstrates that finishing an implanted steer from 400 to 650 kg reduces feed consumed by ~4%. Androgenic hormones (testosterone and trenbolone acetate) directly reduce fat content of the carcass. Oestradiol treatment increases mature body size so at any intermediate bodyweight the animal is less mature and likely to have less fat in the carcass. Hormonal treatment has a negative influence on the tenderness and eating quality of beef, the effect being more pronounced with combination implants than with oestradiol alone. Aging for up to 28 days of those muscles that age extensively helps to overcome the detrimental hormonal growth promotant effect.