Within a dairy herd, total milk production is determined by the proportion of cows producing milk at any given time and the level of milk production of the individual cows within the herd. Improving reproductive efficiency helps to maintain the maximal number of cows producing milk at optimal levels. Reproductive efficiency in dairy cattle currently is suboptimal primarily due to four factors: ...

Poor reproductive efficiency is a worldwide problem that has affected the dairy industry during the last several decades. In an attempt to explain the changes in reproductive physiology caused by high milk production, a model of elevated steroid metabolism in lactating dairy cows has been proposed. A slow increase in levels and low peak levels of estradiol (E₂) and progesterone (P₄) characteriz...

Profitability of different grouping criteria was simulated in a dairy farm with 153 lactating cows that were divided into three groups of high (79), medium (40) and low (34) cows based on the milk records. Animals were reassigned to the new groups based on the following criteria using a decision support tool and the same three groups scenario: fat corrected milk 4%, days in milk (DIM), dairy me...

the aim of this study was to consider reproductive performance parameters and blood progesterone concentration changes in high-producing dairy cows (39±2 kg per day) after artificial insemination, in summer and winter. 270 heads of holstein dairy cattle were choose in three big dairy farms, and blood samples were collected at days seven, ten and fourteen after artificial insemination. temperatu...

Although the number of dairy farms is decreasing, that of large farms is increasing in Japan. Milk production in Japanese dairy cows has increased from 62 kg/year to 88 kg/year over the last 2 decades. However, Japanese dairy cows are experiencing a sustained decline in reproductive performance, calving intervals, and days open; further, the number of inseminations required for conception have ...

In early postpartum, high-producing dairy cows undergo a period of extensive tissue catabolism because of negative nutrient balance. Metabolic unbalances can lead to diseases, which are known to depress fertility in dairy cows. Negative nutrient balance has been associated with compromised immune and reproductive functions in dairy cows, and a compromised immune system leads to greater risk of ...

The efficient production of milk drives the profitability of the dairy enterprise. Within a dairy herd, total milk production is determined by the proportion of cows producing milk at any given time and the level of milk production of the individual cows within the herd (Vandehaar, 1998). Both of these factors are dramatically affected by reproductive efficiency. Improving reproductive efficien...

The expression of oestrous behaviour in Holstein Friesian dairy cows has progressively decreased over the past 50 years. Reduced oestrus expression is one of the factors contributing to the current suboptimal reproductive efficiency in dairy farming. Variation between and within cows in the expression of oestrous behaviour is associated with variation in peripheral blood oestradiol concentratio...

Subacute Ruminal Acidosis (SARA) corresponds to an imbalance between lactate-producing bacteria and lactate-using bacteria, which results in a change in ruminal pH associated with a prevalent consumption of rapidly fermentable carbohydrates. In our study, 216 primiparus and multiparus dairy cows were selected from 20 Italian intensive dairy herds and were divided into three groups based on the ...

One of the primary objectives of dairy producers is to promote dry matter intake (DMI) to support milk production. Considerable research to date has focused on improving the DMI of lactating dairy cows by changing the nutrient composition of feeds. However, the DMI of group-housed lactating dairy cows is also affected by feeding behavior, which is modulated by the environment, management, healt...