Thermoregulation in intensively lactating cows in near-natural conditions

Thermoregulation in fasting emperor penguins under natural conditions.

Emperor penguins breed during the cold antarctic winter. The males incubate the single egg while fasting for up to 4 mo and losing some 20 kg of their body mass. Fasting captive birds under outdoor conditions lost from 0.145 to 0.434 kg day -1. Mean resting metabolic rate, 49.06 W for 24.8 kg body mass, is 7 and 27%, respectively, higher than predicted from general metabolic equations for birds...

Estrous Synchronization in Lactating Cows

Pyruvate and Propionate Metabolism in Lactating Cows

The glucogenic behavior of butyrate in ruminants has been reported frequently, but the metabolic nature of this anomalous relationship has remained obscure. To test the possibility that the metabolism of butyrate affects gluconeogenesis, lactating cows were given intravenous injections of tracer amounts of pyruvate-2-14C and, in parallel experiments, of pyruvate-2-l% plus substrate amounts of s...

Economic Value and Produced Milk Quality in Holstein Lactating Cows in Organic System

In the past decade, a global demand for products from organic agriculture has increased rapidly. Milk quality is of major interest for all parties. Therefore, the objective of this study was to compare cow performance and product quality in conventional and organic system. Twenty Holstein dairy cows were allotted to one of 2 diet groups, which including: a conventional diet (CON), and an organi...

the effects of high non fibrous carbohydrates diet on milk production, inflammation and molecular mechanism of innate immunity in lactating dairy cows

پژوهش حاضر با هدف بررسی اثر جیره حاوی کربوهیدراتهای غیرالیافی زیاد و بروز التهاب در گاوهای شیرده در دو آزمایش جداگانه انجام شد. در آزمایش اول 20 رأس گاو مبتلا به ورم پستان از دو گروه کم تولید و پرتولید (هر کدام 10 رأس) و 20 رأس گاو سالم از دو گروه کم تولید و پرتولید (هر کدام 10 رأس) انتخاب شدند. همه گاوها در دوره دوم و یا سوم شیردهی و در روزهای 80-120 پس از زایش بودند. میانگین تولید شیر در گروه...