Lactation: historical patterns and potential for manipulation.

نویسنده

  • D G Blackburn
چکیده

The advent of biotechnology has made data on undomesticated mammals relevant to dairy science. Such data indicate the potential of lactation for modification, reveal genetic material available for use through bioengineering, help distinguish adaptive features from historical artifacts, and clarify limits on lactational diversity that date from early evolution. Evolutionary analysis indicates that a complex degree of lactation preceded divergence of the extant mammalian lineages during the Mesozoic Era. Although aspects of monotreme lactation appear to be ancestral for extant mammals, the marsupials and eutherians exhibit divergent specializations. Evidence is consistent with the idea that protolacteal glands evolved by combining features of skin gland populations into a new functional complex. Secretions of these ancestral glands may have had antimicrobial properties that protected the eggs or hatchlings and organic components that supplemented offspring nutrition. Following development of highly nutritious milks, evolution produced diversity in milk composition and function, milk output, length of lactation, mammary gland anatomy, and contributions of lactation to offspring nutrition. Certain marsupials are specialized in terms of functional independence and temporal plasticity of mammary tissues. Mammalian diversity indicates that artificial selection and physiological manipulation of domestic artiodactyls has only modestly exploited the potential of mammary glands as a nutritional source for humans.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Relationships of Hofstede's Cultural Dimensions and Lactation Patterns in Lactating Mothers

Background: Exclusive breastfeeding is the best pattern for feeding infants in the first 6 months of life. On the other hand, lactation patterns may be influenced by cultural factors. The present study aimed to determine relationships of Hofstede's cultural dimensions and lactation patterns in lactating mother. Material...

متن کامل

Exploring the Patterns of In-Between Spaces in Guilan Historical Houses

The aim of this paper is to explain the spatial patterns of in-between spaces in Guilan historical houses in order to show their potential capacity in having various functions, and thus different forms, in the course of history. In-between spaces are mediators between two other spaces making them accessible or visible for each other. An explanation of their spatial patterns can both reveal the ...

متن کامل

Impact of Oxytocin-Milking Method on Lactation Performance and Lactation Length of Sheep

Determination of milk yield potential using an accurate method is essential for assessing nutritional requirements, evaluation of genetic potential, lamb growth and survival, management decisions and improving performance traits of sheep flocks. Exogenous oxytocin injection is applied to estimate milk secretion rate in sheep. Oxytocin is a neurohormone produced in the hypothalamo-neurohypophysi...

متن کامل

Effect of Water and Temperature on Seed Germination and Emergence as a Seed Hydrothermal Time Model

The physiological process of germination depends on several environmental factors such as temperature, water potential, light, nutrients and smoke. Water and temperature are determinant factors for seed germination. Both factors can, separately or jointly, affect the germination percentage and germination rate. The effect of temperature on germination and water potential on germination canoften...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Journal of dairy science

دوره 76 10  شماره 

صفحات  -

تاریخ انتشار 1993