The objective of the present study was to determine the effect of substitution of corn grain with dried citrus pulp (DCP) on milk composition, fatty acids profiles and blood metabolites in Holstein dairy cows. These parameters were measured in a replicated 4 × 4 latin square design experiment using eight Holstein cows. Each experimental period lasted 4 weeks. The four treatments were: control (...

The objective of the present study was to determine the effects of rumen-protected choline (RPC) supplementation on body condition, milk production and milk choline content during the periparturient period. Thirty-two Holstein cows were allocated into two groups (RPC group - with RPC supplementation, and control group - without RPC supplementation) 28 days before the expected calving. Cows were...

The objective of this study was to investigate the effect of a partial substitution of soybean meal with field pea (Pisum sativum) in Holstein lactating dairy cow diets on dry matter intake, milk yield and composition, blood metabolites, rumen ammonia-N concentration and pH. Eighteen lactating Holstein cows were randomly assigned into three groups based on parity, days in milk, and mil...

Ten lactating multiparous Holstein cows were used in a cross-over design with two dietary treatments and 28-d periods (with 14 d as an adaptation) to study the effect of restaurant fat on milk production and composition. Each cow was offered 14.7 kg DM /d of the basal concentrate diet based on barley and corn (crude protein = 17.7%, neutral detergent fiber = 23.5%, and acid detergent fiber = 5....

Using monthly test day records the genetic parameters of Iranian Holstein cattle in first lactation were studied. Data of 277400 test-day milk records from 65320 cows and 2210 sires were analyzed by an animal random regression model using restricted maximum likelihood methodology. The model included herd-test-date, interaction between year-season of calving, days in milk (linear and quadratic) ...

Although it has long been known that there are seasonal variations in the chemical characteristics of butterfat, it has as yet not been possible to assess the relative importance of nutritional and lactational influences. Moreover, in the Northern Hemisphere the problem is further complicated by the climatic effects, which necessitate the maintenance of cows indoors during the colder months, th...

-A feeding trial was conducted in eight cows to compare the effect of supplementing commercial yeast species Saccharomyces cerevisiae and Saccharomyces siccum on milk yield and its composition. Cows were randomly assigned to one of the two treatment groups consisting four animals each. Commecial yeast granules were added at the rate of 25 g /cow / day to the concentrate feed in the afternoon fo...

Forty-eight primiparous and pregnant Holstein cows at 202 (+/-59) days in milk and average daily milk production (DMP) of 22 (+/-5.3) kg at the beginning of the trial were used to study the possibility of identifying animals that are more responsive to recombinant bovine somatotropin (rbST). Animals were housed in free-stall barns, milked three times a day and fed a total mixed ration. Animals ...

Aiming at the determination of the metabolic disorder prevalence as well as the effect of subclinical disorders on daily milk traits of Holsteins, over 1 million (1 962 831) test day records were analysed. The metabolic disorder (ketosis or acidosis) prevalence was indicated by the fat-to-protein (F/P ) ratio, while subclinical disorder was indicated by the F/P ratio and cows’ daily production....

The study was conducted to assess the effect of milk production, parity, stage of lactation, season and individual milk components themselves on milk urea nitrogen (MUN) concentration and other milk components of 3,219 Holstein dairy cows in Korean dairy farms. The MUN concentrations in Korean dairy cows were estimated to 16.68±5.87 mg/dl. Milk yield was negatively correlated with fat and prote...