Comparison of 3-breed rotational crossbreds of Montb?liarde, Viking Red, and Holstein with Holstein cows fed 2 alternative diets for dry matter intake, production, and residual feed intake

The objective of this study was to compare 3-breed rotational crossbred (CB) cows of the Montbeliarde, fed 2 alternative diets for dry matter intake (DMI), fat plus protein production (CFP), body weight (BW), body condition score (BCS), feed efficiency, and residual feed intake (RFI) from 46 to 150 days in milk (DIM) during first lactation. The CB cows (n = 17) and HO cows (n = 19) calved from September 2019 to March 2020. Cows were fed either a traditional total mixed ration diet (TRAD) or a higher fiber, lower starch total mixed ration diet (HFLS). The HFLS had 21% more corn silage, 47% more alfalfa hay, 44% less corn grain, and 43% less corn gluten feed than the TRAD. The 2 diets were analyzed for dry matter content, crude protein, forage digestibility, starch, and net energy for lactation. The BW and BCS were recorded once weekly. Daily milk, fat, and protein production were estimated from twice monthly milk recording with random regression. Measures of efficiency were CFP per kilogram of DMI and DMI per kilogram of BW. The RFI from 46 DMI on milk energy, metabolic BW, and the energy required for change in BW. Statistical analysis of all variables included the fixed effects of diet, breed group, and the interaction of diet and breed group. The CB cows fed HFLS had less DMI (-12%) and lower DMI/ BW (-14%) compared with the HO cows fed TRAD. For CFP, CB and HO cows were not different when fed had higher BW (+50 kg) compared with HO cows fed and +0.62, respectively). The HO cows fed TRAD had more DMI (+14%) and lower CFP per kilogram of DMI (-12%) compared with the HO cows fed HFLS. In addition, mean RFI from 46 to 150 DIM was lower and more desirable for CB cows fed HFLS (-120.0 kg) compared with HO cows fed TRAD (85.3 kg). Dairy producers may feed either TRAD or HFLS to CB cows without loss of CFP.

Automated summary

This study compared the differences in dry matter intake, milk production, body weight, body condition score, and feed efficiency between CB cows and HO cows fed with different diets. When CB cows were fed with the HFLS diet, compared to HO cows fed with the TRAD diet, the dry matter intake and body weight decreased, while milk production, fat plus protein production, and feed efficiency showed no significant differences. In terms of residual feed intake, CB cows fed with the HFLS diet had lower and more desirable values compared to HO cows fed with the TRAD diet.