two experiments studied the effects of canola or sunflower seed supplementation on conjugated linoleic acid (cla) concentration in milk fat of lactating cows. in each experiment, only eight cows in early lactation were available to assign to one of two treatments in a completely randomized design and were fed individually for 12 wk. experiment 1 compared similar diets with or without the additi...

The transition from pregnant, non-lactating to non-pregnant, lactating is too often a disastrous experience for the cow. Most of the metabolic diseases of dairy cows milk fever, ketosis, retained placenta, and displacement of the abomasum occur within the first 2 wk of lactation. In addition to metabolic disease, the majority of infectious disease experienced by the dairy cow, especially mastit...

this study was conducted to evaluate the effects of extruded linseed on milk production, dry matter intake and reproduction performance of 300 holstein lactating cows (35±15 days in milk; 41±9/8 kg/day of milk production). cows were utilized in a completely randomized experimental design, comprised of: 2 treatments (concentrate containing 7 percent extruded linseed vs control) with a number of ...

this study was conducted to evaluate the effects of alfalfa hay (ah) particle size and soybean hull (sh) on physical effective fibre (pendf), particle size distribution in diets, chewing activity as well as milk composition and production in early lactating dairy cows. eight lactating holstein cows averaging 590±33 kg of bw and 47±13 days in milk were assigned in a 4×4 latin square design to a ...

Group G streptococci in animals usually belong to the species Streptococcus canis and are most commonly found in dogs and cats. Occasionally, Strep. canis is detected in milk from dairy cows. An outbreak of Strep. canis mastitis in a dairy herd is described. Based on results from bacterial culture and ribotyping, a cat with chronic sinusitis was the most likely source of the outbreak. Subsequen...

Using two PGF(2α) treatments 14 days apart as a way to enhance estrus detection rate following the 2nd treatment is a reproductive management tool that continues to be used on large dairy farms. In one study, in cows with a functional CL and a dominant follicle, treatment with cloprostenol vs. dinoprost resulted in greater peripheral estradiol concentrations. The objective of the present study ...

The objective of this study was to determine the long-term effects of feeding monensin on methane (CH4) production in lactating dairy cows. Twenty-four lactating Holstein dairy cows (1.46 +/- 0.17 parity; 620 +/- 5.9 kg of live weight; 92.5 +/- 2.62 d in milk) housed in a tie-stall facility were used in the study. The study was conducted as paired comparisons in a completely randomized design w...

Several temperature-humidity indexes (THI) have been used to estimate the degree of thermal stress experienced by dairy cows. The present objectives were to develop equations using meteorological variables that predicted rectal temperature of lactating cows in a subtropical environment and compare the goodness of fit of these equations to those using 8 different THI. Rectal temperature was meas...

To establish sustainability in the dairy industry, it is important that cows become pregnant at a biologically optimal time and at an economically profitable interval after calving. In this review, the results obtained from Holstein cattle in an experimental herd for dairy research are summarized. First, the effect of age at first calving of heifers on productive and reproductive performance wa...

Dairy cows enter a period of energy insufficiency after parturition. In liver, this energy deficit leads to reduced expression of the liver-specific GH receptor transcript (GHR1A) and decreased GHR abundance. As a consequence, hepatic processes stimulated by GH, such as IGF-I production, are reduced. In contrast, adipose tissue has been assumed to remain fully GH responsive in early lactation. ...