ABSTRACT
The aim of this study was to describe the morphology and estimate live weight from body measurements of Socorro Island Merino lambs. A group of Socorro Island Merino lambs was recorded from birth to year for live weight, rump width, rump length, withers height, body length, cannon bone perimeter, and chest girth, width, and depth. The effect of the lamb type on body measurements and live weight was analyzed using ANOVA, Pearson's correlation analysis was performed to estimate the relationship between body measurements and live weight, multiple linear regressions were fitted to obtain prediction equations of live weight from the body measurements and finally, chest girth was used to generate prediction equations using linear and exponential models. At birth and at year, differences were observed in body measurements, especially those related to the thoracic region, with crossbred males showing the highest values. Live weight was correlated with almost all the body measurements, with the highest coefficients observed with chest girth, chest width, and chest depth. Live weight can be accurately predicted from multiple regression equations using several body measurements, but using only chest girth (CG) as a predictor, the exponential equation W0-365 = 0.9142 exp(0.0462 CG) showed the best accuracy.
ABSTRACT
To establish reference values for biochemical analytes related to freshwater shortage adaptation, a total of 376 blood samples were collected from feral sheep at Socorro Island, Revillagigedo Archipelago. Year-round variation was assessed by sampling at the beginning of each season defined by the March equinox, June solstice, September equinox, and December solstice. The resulting data set was analyzed using Gaussian distribution and descriptive statistics. Confidence intervals of 95% were established. Analysis of variance was used to compare the mean values of each season. Total cholesterol, triglycerides, urea, albumin, total protein, sodium ion, anion gap, creatine kinase, arginine vasopressin, and aldosterone showed concentrations above the reference range for domestic sheep. Triglycerides, urea, albumin, sodium ion, and aldosterone showed concentrations within the reference range for domestic goats. Most biochemical analytes showed differences (P<0.05) between seasons, with the highest values occurring during winter, and the lowest during spring. Results could help improve the accuracy of metabolic profiles used as a tool for evaluating dehydration indicators, and to describe the physiological mechanisms employed by feral sheep to cope with seasonal availability of freshwater.(AU)
Para estabelecer valores de referência para analitos bioquímicos relacionados à adaptação da escassez de água doce, um total de 376 amostras de sangue foram coletadas de carneiros selvagens na ilha de Socorro, no arquipélago de Revillagigedo. A variação durante todo o ano foi avaliada por amostragem no início de cada estação definida pelo equinócio de março, solstício de junho, equinócio de setembro e solstício de dezembro. O conjunto de dados resultante foi analisado usando distribuição Gaussiana e estatística descritiva. Intervalos de confiança de 95% foram estabelecidos. A análise de variância foi usada para comparar os valores médios de cada estação. O colesterol total, triglicerídeos, ureia, albumina, proteína total, íon sódio, hiato aniônico, creatina quinase, arginina vasopressina e aldosterona apresentaram concentrações acima do intervalo de referência para carneiros domésticos. Triglicerídeos, ureia, albumina, íon sódio e aldosterona apresentaram concentrações dentro da faixa de referência para cabras domésticas. A maioria dos analitos bioquímicos apresentou diferenças (P<0,05) entre as estações, com os maiores valores ocorrendo no inverno e os menores na primavera. Os resultados podem ajudar a melhorar a precisão dos perfis metabólicos usados como uma ferramenta para avaliar os indicadores de desidratação e descrever os mecanismos fisiológicos empregados pelas carneiros selvagens para lidar com a disponibilidade sazonal de água doce.(AU)
Subject(s)
Animals , Sheep/blood , Dry Season , Dehydration/blood , Seasons , Animals, Wild/blood , MexicoABSTRACT
A study was conducted with the objective to characterize the morphology of Socorro Island Merino sheep. A total of 67 sheep, 62 females, 26 purebred and 36 crossbred with hair breeds, and five males were scored for 10 body measurements in addition to live weight, and four racial and seven functional indices were calculated. The influence of sex and crossbreeding on the body measurements and indices was analyzed by one-way analysis of variance, and morphological harmony was determined using Spearman correlation. With exception of rump length, body measurements and live weight were significantly greater in males than in females. Sexual dimorphism was 1.21, with males being 78 % heavier than females. Socorro Island Merino sheep were dolichocephalous, elipometric, with a convex curve rump, and with a high and low morphological harmony for females and males, respectively. They had undefined zootechnical aptitude tended toward dairy phenotype as long as crossbreeding with hair breeds did not affect their functional or productive aptitude. It can be concluded that Socorro Island Merino sheep is a new biotype of the Merino breed, which is necessary to preserve and evaluate as a source of genetic characteristics such as adaptation to harsh environmental conditions.
