Relationships between milk urea concentrations and nutritional management, production, and economic variables in Ontario dairy herds.
نویسندگان
چکیده
The objectives of this study were to describe the relationships between milk urea concentrations and nutritional management, production, and economic variables in commercial dairy herds. Dairy Herd Improvement (DHI) test-day milk urea data, production data, and information on ration nutrient composition and feeding management programs were collected over a 13-mo period from 53 commercial Ontario dairy herds. Economic variables included gross milk revenue, feed costs, and income over feed costs. Herd mean milk urea concentrations had a positive relationship with dietary levels of crude protein (CP), rumen degradable protein (RDP), and rumen undegradable protein (RUP) and a negative relationship with dietary levels of nonfiber carbohydrates (NFC), forage:concentrate (F:C) ratio, NFC:CP ratio, and NFC:RDP ratio. These findings are consistent with experimental studies that used chemical methods of milk urea analysis. Herd mean milk urea concentration was not associated with feeding management (e.g., total mixed rations, component feeding, feeding frequency, or synchrony of forage and concentrate feeding). Herd mean milk urea was not associated with either mean milk yield or linear score. Herd mean milk urea had a positive relationship with feed costs per cow per day but was not associated with gross milk revenue per cow per day. Herds with a high mean milk urea concentration tended to have lower income over feed costs per cow per day. High herd mean milk urea concentrations were associated with higher feed costs per kilogram of milk fat but lower gross milk revenue and lower income over feed costs per kilogram of milk fat. The results of this study demonstrate that DHI milk urea measurements produced by an infrared test method offer a useful tool for monitoring the efficiency of nitrogen utilization in commercial dairy herds. The results also suggest that diets may be balanced to achieve greater efficiency of nitrogen utilization, lower milk urea concentrations, and lower feed costs, while still achieving high milk production. This may lead to improved income over feed costs.
منابع مشابه
Factors associated with milk urea concentrations in Ontario dairy cows.
All DHI test-day data, including milk urea concentrations measured by infrared test method, were collected from 60 commercial Ontario Holstein dairy herds for a 13-mo period between December 1, 1995, and December 31, 1996. The objectives of this study were to describe the relationships between milk urea concentrations and seasonal factors, sampling factors, cow factors, and test-day production ...
متن کاملهمبستگی نیتروژن اورهای خون، نیتروژن اورهای شیر و باروری گاوهای شیرده
The purpose of this study was to evaluate nutritional status in Isfahan dairy herds and the relationship between milk urea nitrogen (MUN) and fertility in the first postpartum insemination. Blood and milk samples were collected from 170 and 290 Holstein cows from 9 dairy herds, respectively. Feed samples were also collected to quantify the relationship between MUN and protein and energy content...
متن کاملهمبستگی نیتروژن اورهای خون، نیتروژن اورهای شیر و باروری گاوهای شیرده
The purpose of this study was to evaluate nutritional status in Isfahan dairy herds and the relationship between milk urea nitrogen (MUN) and fertility in the first postpartum insemination. Blood and milk samples were collected from 170 and 290 Holstein cows from 9 dairy herds, respectively. Feed samples were also collected to quantify the relationship between MUN and protein and energy content...
متن کاملSources of variation in milk urea nitrogen in Ohio dairy herds.
The purpose of this study was to estimate the amount of variation in milk urea nitrogen (MUN) concentrations attributable to test-day, individual cow, and herd effects and to describe factors associated with MUN measurements in Ohio dairy herds. The data came from 24 Holstein herds, half of which were classified as low producing (LP) [rolling herd average (RHA) milk production < 7,258 kg] and h...
متن کاملEffect of Milk Urea Nitrogen of Dairy Cows in Relation to Breed
Milk urea nitrogen (MUN) of dairy cows was determined in relation to breed. A total of forty (40) Pabna and red Chittagong dairy cattle each of twenty (20) were selected to know the milk composition, nutritional status and milk urea nitrogen. Live weight of Pabna Cattle (187±14 kg) was higher than that of red Chittagong cattle (174±4 kg). In Pabna cattle milk yield (4.94 kg), minerals (0.15%) a...
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ورودعنوان ژورنال:
- Journal of dairy science
دوره 84 5 شماره
صفحات -
تاریخ انتشار 2001