Poor utilization of amino acids contributes to losses of milk protein yield in dairy cows exposed to heat stress (HS). Our objective was to test the effect of essential amino acids on milk production in lactating dairy cows exposed to short-term HS conditions. To achieve this objective, 12 multiparous, lactating Holstein cows were assigned to two environments (thermoneutral (THN) or HS) from da...

This study was conducted to determine a proper feeding regime for lactating Holstein cows during the warm season in Taiwan. In Feeding Trial, 21 lactating Holstein cows were randomly allotted into three feeding regimes in a Completely Randomized Design. The feeding regimes were roughage fed ad libitum along with concentrate fed either twice daily (2C) or four times daily (4C), and total mixed r...

Bovine viral diarrhoea virus (BVDV) is an important pathogen of dairy cattle. In this study, bulk milk samples representing a total of 4105 milking cows, from 18 dairy cattle herds in the suburb of Mashhad- Iran, were tested for presence of BVDV by the use of a nested reverse transcription polymerase chain reaction (Nested RT- PCR) assay. Non of the cows in the herds had been vaccinated against...

Thirty-eight lactating dairy cows including 6 ruminally cannulated cows were used in a feeding study to assess effects of feed sources that differed in dietary nonfiber carbohydrate (NFC) composition and ruminal degradability of dietary protein (RDP) on production, ruminal, and plasma measures. The design was a partially balanced, incomplete Latin square with three 21-d periods and a 3 x 2 fact...

to compare the nutritional value of rapeseed meal and cottonseed meal in holstein cows, feeding 20 lactating holstein cows each with an average weight of 580± 34 kg and 100± 10 days in milk were studied in a randomized complete block design. the experimental diets consisted of 4 levels of 0, 8, 14 and 25 percent rapeseed meal replaced with cottonseed meal and barley grain in the diets. diets we...

Increasing dietary energy density by feeding supplemented fat may enhance lactation performance as well as metabolic efficiency of lactating cows (Kronfeld 1980). Inadequate energy intake prepartum and during early lactation has been associated with increased incidences of metabolic disorders (Curtis et al. 1985) and poor reproductive performance. The aim of this study was to determine the effe...

The effects of utilizing evaporative cooling system equipped with tunnel ventilation on postpartum ovarian activities, energy balance and milk production of early lactating dairy cows under hot and humid climates were studied from parturition to 22 wk postpartum. Thirty-four crossbred Holstein-Friesian (93.75% HF×6.25% Bos indicus) primiparous cows were randomly assigned to one of two groups. C...

Current NRC recommendations for dairy cattle provide limited guidance to nutritionists for meeting the fiber and carbohydrate needs of lactating cows. The NRC provide only minimum recommendations for fiber and no accommodation for factors such as physical effectiveness of fiber, interactions with nonfibrous carbohydrates, or animal attributes, which can affect the optimality of dairy rations. T...