Suitability of Small and Large Size Dairy Cows in a Pasture-Based Production System

Pasture-based dairy production with greatly reduced supplemental feeding and block-calving in spring is increasingly applied in Switzerland. The prevalent cow type has been selected mainly for high individual production in a barn feeding system with balanced diet. This cow type has continuously increased in size over the last 30 years. The question arises whether this type is suitable for the new system, and particularly if cow size is a critical factor. Theoretically a large, heavy type of cow has a higher intake capacity, while the nutrient requirements for a small, light type are easier to satisfy

Prediction of drinking water intake by dairy cows

Mathematical models that predict water intake by drinking, also known as free water intake (FWI), are useful in understanding water supply needed by animals on dairy farms. The majority of extant mathematical models for predicting FWI of dairy cows have been developed with data sets representing similar experimental conditions, not evaluated with modern cows, and often require dry matter intake (DMI) data, which may not be routinely available. The objectives of the study were to (1) develop a set of new empirical models for predicting FWI of lactating and dry cows with and without DMI using literature data, and (2) evaluate the new and the extant models using an independent set of FWI measurements made on modern cows. Random effect meta-regression analyses were conducted using 72 and 188 FWI treatment means with and without dietary electrolyte and daily mean ambient temperature (TMP) records, respectively, for lactating cows, and 19 FWI treatment means for dry cows. Milk yield, DMI, body weight, days in milk, dietary macro-nutrient contents, an aggregate milliequivalent concentration of dietary sodium and potassium (NaK), and TMP were used as potential covariates to the models. A model having positive relationships of DMI, dietary dry matter (DM%), and CP (CP%) contents, NaK, and TMP explained 76% of variability in FWI treatment means of lactating cows. When challenged on an independent data set (n=261), the model more accurately predicted FWI [root mean square prediction error as a percentage of average observed value (RMSPE%)=14.4%] compared with a model developed without NaK and TMP (RMSPE%=17.3%), and all extant models (RMSPE%≥15.7%). A model without DMI included positive relationships of milk yield, DM%, NaK, TMP, and days in milk, and explained 63% of variability in the FWI treatment means and performed well (RMSPE%=17.9%), when challenged on the independent data. New models for dry cows included positive relationships of DM% and TMP along with DMI or body weight. The new models with and without DMI explained 75 and 54% of the variability in FWI treatment means of dry cows and had RMSPE% of 12.8 and 15.2%, respectively, when evaluated with the literature data. The study offers a set of empirical models that can assist in determining drinking water needs of dairy farms

Effect of Animal Grouping on Feeding Behavior and Intake of Dairy Cattle

Although data are scarce, it is clear that grouping strategy can have a significant impact on the feeding behavior and feed intake of dairy cattle. Feed intake is controlled by ruminoreticular fill and physiological mechanisms, but grouping is a component of the cow’s feeding environment that can modulate intake as a result of its impact on cow comfort, competition for feed and other resources, and herd health. Social dominance and competition for feed impact feeding behavior and proper grouping strategy will minimize the negative impact of excessive competition on intake and enhance beneficial effects of group feeding such as social facilitation. Primiparous cows benefit from separate grouping from older animals by increased intake and productivity. Bunk space, accessibility of feed, and type of feeding system must be considered when determining the optimal group size. There appears to be no problem with large (\u3e200 cows) groups of cows per se, but management decisions such as overcrowding with insufficient head gates or manger space play a role in determining cow well-being and feeding behavior. Research with group sizes larger than 400 cows needs to evaluate productivity, feeding and other behavior, and animal well-being. Significant overcrowding appears to reduce feeding activity, alter resting behavior, and decrease rumination activity. Negative social consequences of moving cows between groups last 3 to 7 d. Although the effect of grouping on feeding behavior remains largely unquantitated at this point, the effect is potentially large and requires further research to describe the impact of cow dynamics within a group on feed intake