High-immune quality colostrum (IgG1 concentration ⩾50 g/l) is crucial for the health and development of the young calf. Studies on colostrum quality tend to focus on external factors such as breed, parity or dry period length, but few have focused on within-cow variations. Here we ran experiments to gain a deeper insight into within-cow variation in IgG1 concentrations in dairy cow colostrum. T...

Genetic and environmental factors that might affect gestation length (GL) were investigated. Data included information from >11 million parturitions from 1999 through 2006 for 7 US dairy breeds. Effects examined were year, herd-year, month, and age within parity of conception; parturition code (sex and multiple-birth status); lactation length and standardized milk yield of cow; service sire; co...

Lameness causes major financial losses and welfare problems in dairy herds. Prevention of foot lesions may suffice in the majority of lameness cases. The objectives of this longitudinal study were to describe the dynamics and associations between abnormal hind leg conformation, asymmetric claws, lameness, and foot lesions in 122 Danish Holstein heifers from an average of 41 d before first calvi...

The objectives of the study were to compare the ovarian activity of Holstein-Friesian (CH HF), Fleckvieh (CH FV) and Brown Swiss (CH BS) dairy cows of Swiss origin with that of Holstein-Friesian (NZ HF) dairy cows of New Zealand origin, the latter being used as a reference for reproductive performance in pasture-based seasonal calving systems. Fifty, second-lactation NZ HF cows were each paired...

The objective of the experiment was to determine the effects of fat supplementation on embryo quality of dairy cows and the subsequent success of embryo transfer into recipient heifers fed the same sources of fat. A total of 30 lactating Holstein cows were allotted on d 18 postpartum to 2 groups of 15 donor cows blocked for similar calving dates. Total mixed diets based on silage and fat supple...

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...

Two experiments were conducted to evaluate dry matter intake (DMI), milk yield, and milk composition from feeding rations that contained different sources of genetically modified whole cottonseed to Argentinean Holstein dairy cows. Twenty-four lactating multiparous Argentinean Holstein dairy cows were used in 2 experiments with a replicated 4 x 4 Latin square design, with cows averaging 565 kg ...

The major aim of this study was to compare the morphology and activity of rumen protozoa of Khuzestan water buffalo and Holstein cow using in vitro digestibility and gas production parameters of steam treated sugarcane pith. Rumen fluid obtained from two buffalo and cow steers fed the same diet, 30:70 concentrate: forage. To separate rumen protozoa, antibiotic solution and fungicides were added...

In order to improve animal welfare it is recommended that dairy farmers move calving cows from the herd to individual pens when calving is imminent. However, the practicality of moving cows has proven a challenge and may lead to disturbance of the cows rather than easing the process of calving. One solution may be to allow the cow to seek isolation prior to calving. This study examined whether ...

The objective of this study was to quantify the phenotypic and genetic risk factors associated with multiple ovulations and twin births in cattle. Prevalence and cow- and herd-level risk factors associated with ovulation rate were determined using 40,617 ultrasonographic records of the reproductive tract from 27,907 dairy and beef cows from 738 commercial herds. Prevalence of twin births was es...