Two experiments were conducted to estimate the effect of protein malnutrition (2 vs 17% protein diet during gestation and 5 vs 17% during lactation) on sow and progeny performance and learning ability of the offspring. Gestation gain and birth weights were significantly decreased (P<.05), but litter size at birth was not significantly affected by feeding the low level of protein to the sow. Wei...

The objective was to determine whether the use of estradiol-17beta (E2) at the initiation of short dry periods prevented an anticipated decline in milk production in the subsequent lactation. Lactating Holstein cows (n = 66) were dried at either 60 or 30 d before expected calving. Treatments in a 2 x 2 factorial arrangement included: D60 (n = 19, 60-d dry, no E2), D60 + E2 (n = 18, 60-d dry, E2...

Environmental influences on lactation efficiency are frequently associated with reductions in milk output. Heat stress, for example, leads to depressed feed intake and, subsequently, losses in production. Conversely, cold stress may limit nutrients available for milk synthesis. Fortunately, one environmental factor, photoperiod, can exert a positive effect on dairy performance when managed prop...