Net energy efficiencies of Holstein, Jersey and Holstein-Jersey F1-crosses

Abstract

Net energy efficiencies were calculated from data of an experimental herd with respect to type of cow, lactation number, stage of lactation and diet. The trial consisted of 71 Holstein-Friesians, 71 Jerseys and 71 Holstein-Jersey F1-crosses in 1st, 2nd and > 2nd lactation. Data were collected during 210 days of lactation, from calving to week 30 and included total dry matter intake, energy content of foods, milk yield, milk solids, body weight, body condition scores and several body measurements. The cows were divided into four feeding groups : high and low energy content of roughage as well as high and low proportion of concentrates. Net energy efficiency was calculated as the ratio of milk energy to total net energy intake after subtracting energy utilized for maintenance and body tissue change. Body tissue change was calculated either via body-weight changes or body condition-score changes. Due to the distribution of the efficiencies being skewed, efficiencies were transformed applying a Box-Cox transformation. Transformed net energy efficiencies were analysed using a repeated measurements design considering the sequential nature of the observations. Mixed models with a compound symmetry structure for the variance components were applied. Final models contained the fixed effects of type, lactation number, feeding group and the covariates week of lactation and its square. Holstein-Jersey crosses were more efficient than purebreds, second lactation cows were least efficient, cows given low energy roughage and a lower proportion of concentrates were more efficient than cows on the other diets. Least efficient were the cows belonging to the high energy roughage and higher proportion of concentrates group. The coefficients of determination of the final models were between 0·357 and 0·492.

Three-breed rotational crossbreds of Montbéliarde, Viking Red, and Holstein compared with Holstein cows for feed efficiency, income over feed cost, and residual feed intake

“…The Jersey breed was later replaced with the VR breed for an ongoing 3-breed rotational system of HO, MO, and VR. A description of the crossbreeding design and genetic level of cows in this study was reviewed in Shonka-Martin et al (2019).…”

“…Some cows were involuntarily culled, and cows that left the herd before 150 DIM were eliminated from the study for only the terminal lactation (Shonka-Martin et al, 2019). Less than 9% of the lactations of cows were eliminated for cows that left the herd before 150 DIM.…”

“…The multiparous analysis had 43 lactations (15 with a HO sire, 15 with a MO sire, and 13 with a VR sire) of CB cows and 37 lactations of HO cows. More details about the cows in this study were reviewed by Shonka-Martin et al (2019).…”

“…The BCS was evaluated on all cows once per week by a single trained evaluator and was scored on a 5-point scale with 0.25 increments, where 1 = thin and 5 = obese (Wildman et al, 1982). Additional details about the FI, BW, and BCS of individual cows, as well as the ingredients and nutritional composition of the diet, are presented in Shonka-Martin et al (2019).…”

“…Research on FE of crossbred cows has mostly focused on Jersey × HO crossbreds, and the results have been mixed. Schwager-Suter et al (2001) reported Jersey × HO crossbreds in a confinement system had more FE than pure HO cows because of a higher ratio of ECM to net energy intake. Prendiville et al (2009) found Jersey × HO crossbreds had a higher ratio of milk solids to DMI over a total lactation in a pasture system.…”