Effect of β-casein A1 or A2 milk on body composition, milk intake, and growth in Holstein, Simmental, and crossbred dairy calves of both sexes.

The aim of this study was to compare the effects of feeding homozygous β-CN A1 or A2 milk on the body composition, milk intake, and growth of German Holstein (GH), German Simmental (GS), and crossbred (CR) dairy calves of both sexes during the first 2 wk of life. A total of 104 calves (n = 54 female, f; and n = 50 male, m) from the breed groups GH (n = 23), GS (n = 61), and crossbred GH × GS (n = 20) were evaluated. Calves were weighed after birth and received colostrum ad libitum.

Feed Efficiency and Physiological Parameters of Holstein and Crossbred Holstein × Simmental Cows.

This study aimed to compare the feed efficiency (FE) and physiological parameters of Holstein and crossbred Holstein × Simmental cows in a confinement system during winter and summer. The study was conducted in a dairy farm in southern Brazil by including a total of 48 multiparous cows. The cows were studied for 21 days in two periods, summer and winter, and their daily dry matter intake (DMI), milk yield (MY), rectal temperature (RT), respiratory rate (RR), body weight, and body condition score were recorded.

Rumination time, activity index, and productive performance of Holstein and crossbred Holstein × jersey cows exposed to different temperature-humidity indexes.

The aim of this study was to evaluate the rumination time, activity index, milk yield (MY), physicochemical milk characteristics, and physiological indicators of pure Holstein (H) and first (F1- ½ Holstein × Jersey) and second-generation (R1- ¾ Holstein × ¼ Jersey) of crossbred cows in a pasture-based system under the influence of different temperature-humidity indexes (THI). Twenty-two multiparous cows (H = 7, F1 = 5, and R1 = 10) were evaluated throughout 1-year period. Daily information on rumination time and activity index was obtained using the software HealthyCow24® and the daily THI was determined from data logger information.

Evaluation of an electronic system for monitoring dairy cow rumination in a grazing-based system.

This research aimed to compare the rumination time estimated by an electronic monitoring system with direct visual observations of the rumination of dairy cows in a grazing-based system. Also, it aimed to estimate the agreement between different time intervals of the direct visual observations. To that end, we have observed twelve lactating cows for 16 h a day for 11 days.

Energy Balance Indicators during the Transition Period and Early Lactation of Purebred Holstein and Simmental Cows and Their Crosses.

Crossbreeding in dairy cattle has been used to improve functional traits, milk composition, and efficiency of Holstein herds. The objective of the study was to compare indicators of the metabolic energy balance, nonesterified fatty acids (NEFA), beta-hydroxybutyrate (BHBA), glucose, body condition score (BCS) back fat thickness (BFT), as well as milk yield and milk composition of Holstein and Simmental cows, and their crosses from the prepartum period until the 100th day of lactation at the Livestock Center of the Ludwig Maximilians University (Munich, Germany). In total, 164 cows formed five genetic groups according to their theoretic proportion of Holstein and Simmental genes as follows: Holstein (100% Holstein; = 9), R1-Hol (51-99% Holstein; = 30), first generation (F1) crossbreds (50% Holstein, 50% Simmental; = 17), R1-Sim (1-49% Holstein; = 81) and Simmental (100% Simmental; = 27).