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Context. Fodder beet (FB) is a widely used winter feed in New Zealand's southern regions due to its high yield, consistent quality, and environmental benefits. However, FB is low in crude protein, phosphorus and fibre, and a survey showed that many dairy farmers were concerned that feeding FB may have negative impacts on lifetime performance. Aim. To determine whether winter feeding FB or kale (Ka) to dairy cows, and then their heifer offspring at 1 and 2 years old, affects the heifer performance from birth until the end of their first lactation. Methods. In June-August 2017, pregnant dairy cows were fed FB or kale over winter and then 140 of the resultant heifer offspring were divided into four treatment groups at 9-11 months old according to their dam's winter diet and offered either FB or kale, with pasture baleage. The groups were as follows (dam crop-heifer crop): FB-FB, FB-Ka, Ka-FB, Ka-Ka. The heifers' subsequent performance (growth, stature, milk production, and reproduction) was measured to the end of their first lactation (May 2020), and blood mineral status was monitored from May 2018 to May 2019. This observational study has its limitations, but is useful for generating hypotheses to test in more controlled research. Key results. Heifers grazing FB in winter (June-August) 2018 had lower blood plasma urea and phosphate concentrations than did heifers grazing kale, despite similar dietary crude protein contents. Treatments had no effect on milk production. However, the heifer liveweights were affected and there was an indication of poorer reproductive performance. The FB-FB heifer treatment group had a lower average liveweight than the FB-Ka heifers from 1 to 2.8 years old. Conclusions. Although no impact on milk production for the first lactation was observed, the key results suggest possible negative impacts of feeding heifers FB during winter, particularly if their dam also wintered on FB. Implications. The combined effects of FB dam and heifer winter diets on lifetime productivity warrant further investigation to help develop sustainable FB feeding systems. When feeding FB, we recommend that farmers test their crops and supplements to ensure that sufficient nutrition, in particular protein and phosphorus are provided. [ABSTRACT FROM AUTHOR]

This paper reports the results of a study to understand why some New Zealand dairy farmers are changing from twice-a-day (TAD) to once-a-day (OAD) milking. Increasing herd size, unavailability of suitable labour and changing lifestyle expectations from farmers and their staff have led some to explore OAD milking as a means of alleviating these issues. A convergent interviewing process was used with 21 dairy farmers who had all adopted OAD milking. A marketing approach, based on consumer behaviour theory and farming systems theory, was used to classify farmers into segments based on their different reasons for adoption. Six segments were identified, viz., herd expansion, time needed to build capital, decreasing labour, increasing labour flexibility, feed shortfalls, and herd health, motivating farmers to adopt OAD milking. Farmers in some segments such as herd expansion and feed shortfalls indicated that they were less likely to be long-term adopters than those in the other segments. Farmers interviewed unanimously understood that OAD milking led to reduced milk yield but were generally prepared to tolerate this to achieve their short-term or long-term goals. (Contains 2 tables and 1 figure.)

Feeding fodder beet (FB) to dairy cows in early lactation has recently been adopted by New Zealand dairy producers despite limited definition of feeding and grazing management practices that may prevent acute and sub-acute ruminal acidosis (SARA). This modelling study aimed to characterize changes of rumen pH, milk production and total discomfort from FB and define practical feeding strategies of a mixed herbage and FB diet. The deterministic, dynamic and mechanistic model MINDY was used to compare a factorial arrangement of FB allowance (FBA), herbage allowance (HA) and time of allocation. The FBA were 0, 2, 4 or 7 kg dry matter (DM)/cow/day (0FB, 2FB, 4FB and 7FB, respectively) and HA were 18, 24 or 48 kg DM/cow/day above ground. All combinations were offered either in the morning or afternoon or split across two equal meals. Milk production from 2FB diets was similar to 0FB but declined by 4 and 16% when FB increased to 4 and 7 kg DM, respectively. MINDY predicted that 7FB would result in SARA and that rumen conditions were sub-optimal even at moderate FBA (pH < 5.6 for 160 and 90 min/day, 7FB and 4FB respectively). Pareto front analysis identified the best compromise between high milk production and low total discomfort was achieved by splitting the 2FB diet into two equal meals fed each day with 48 kg DM herbage. However, due to low milk response and high risk of acidosis, it is concluded that FB is a poor supplement for lactating dairy cows. [ABSTRACT FROM AUTHOR]

The objective of this experiment was to use diurnal and temporal changes in herbage composition to create two pasture diets with contrasting ratios of water-soluble carbohydrate ( WSC) and crude protein ( CP) and compare milk production and nitrogen-use efficiency ( NUE) of dairy cows. A grazing experiment using thirty-six mid-lactation Friesian x Jersey cows was conducted in late spring in Canterbury, New Zealand. Cows were offered mixed perennial ryegrass and white clover pastures either in the morning after a short 19-day regrowth interval ( SR AM) or in the afternoon after a long 35-day regrowth interval ( LR PM). Pasture treatments resulted in lower pasture mass and greater herbage CP concentration (187 vs. 171 g kg−1 DM) in the SR AM compared with the LR PM but did not affect WSC (169 g kg−1 DM) or the ratio of WSC/ CP (1·0 g g−1). Cows had similar apparent DM (17·5 kg DM cow−1 d−1) and N (501 g N cow−1 d−1) intake for both treatments. Compared with SR AM cows, LR PM cows had lower milk (18·5 vs. 21·2 kg cow−1 d−1), milk protein (0·69 vs. 0·81 kg cow−1 d−1) and milk solids (1·72 and 1·89 kg cow−1 d−1) yield. Urinary N concentration was increased in SR AM, but estimated N excretion and NUE for milk were similar for both treatments. Further studies are required to determine the effect of feeding times on diurnal variation in urine volume and N concentration under grazing to predict urination events with highest leaching risk. [ABSTRACT FROM AUTHOR]