Steffen Adler

Research Scientist

(+47) 404 82 199
steffen.adler@nibio.no

Place
Tingvoll

Visiting address
Gunnars veg 6, 6630 Tingvoll

To document

Abstract

Interest in dairy cow-calf contact (CCC) systems is growing, yet limited research had been focused on CCC in a pasture setting. Our study aimed to evaluate the performance of pastured dairy cows and calves with or without CCC through machine milk yield and composition, cow body condition score (BCS) and body weight (BW) decrease, and calf body weight gain (BWG). We also examined calf intake of concentrates, artificially reared calves’ milk intake, and the health of both cows and calves. Conducted on a commercial dairy freestall farm and summer farm in Norway from May to August 2021, the study included twenty cow-calf pairs: 17 Norwegian Red (NRF) and three NRF × Holstein crossbreeds. They were divided into two treatments: cow-calf contact (CC, n = 10) or early separation (ES, n = 10), each with two groups of five cow-calf pairs. CC pairs had full CCC on pasture until 6 weeks postpartum and part-time contact in weeks 7 and 8 (weaning). ES pairs were separated 1–3 h after birth, kept on separate pastures with no contact between ES cows and calves. ES calves’ received daily milk allowances of 12–14 L (weeks 0–6), reduced to 8 L (week 7) and further to 4 L (week 8). From week 9, all calves were denied access to any milk (ES) or cows (CC). During weeks 0–6, CC cows had a daily machine milk yield 23.7 kg lower/cow than ES cows. The difference was likely affected by nursing and other factors (parity and inhibited milk ejection), and persisted during weaning, with CC cows delivering 8.3 kg less/cow/day in weeks 10 and 11 postpartum. Fat and protein content in machine milk showed no significant difference, while lactose content was lower in milk from CC cows than ES cows (week 5 postpartum). CC cows had a lower BW decrease compared to ES cows (CC: 913 g/day, ES: 1415 g/day from pasture day one through week 9). ES calves had an average milk intake of 10.7 L/calf/day (weeks 0–6), and consumed more concentrates than CC calves. Calves’ daily BWG did not differ between treatments in weeks 0–6 (CC: 1340 and ES: 1250 g/day) and decreased for both treatments during weaning (CC: 1050 g/day, ES: 920 g/day in weeks 6–9). Inhibited milk ejection during machine milking was a challenge in CC cows, prompting oxytocin injections to prevent mastitis. Allowing calves full CCC or providing whole milk near ad libitum can result in similar BWG and health in calves. Further research should explore strategies to enhance milk ejection in pastured CCC cows.

To document

Abstract

Leys are an important part of northern European livestock production, particularly for ruminants since monogastric animals are limited in their ability to digest the fibres of the forage. Crop fractionation methods are a promising option to make forages more beneficial for monogastric animals and decrease the amount of imported protein feed. A leaf stripping harvesting technique was evaluated at Röbäcksdalen in northern Sweden in mixed grass-clover leys over 2 years. The PremAlfa Mini leaf stripper (Trust'ing-Alf'ing, Nantes, France) worked well in mixed stands, harvesting on average a third of the available forage biomass, primarily in the form of leaves and soft stems from the clover plants. It proved successful in producing a forage fraction that had a significantly higher crude protein (CP) concentration (+39.1%) and lower neutral detergent fibre (aNDFom) concentration (−21.4%) than the pre-harvest mixed sward (all significant at p < .05 level). Due to the remaining high level of aNDFom in the leaf stripper fraction, it is more suited for use as an energy source for monogastrics rather than as a protein supplement. Alternatively, the leaf stripper fraction could be used to increase digestibility and CP content in the feed rations of high producing dairy cows.