Supply Dairy Research Articles

Impact of community gardens on the sustainability of lifestyles: baseline data of the JArDinS study

Abstract Introduction Despite growing evidence for the multiple health benefits of community gardening, longitudinal studies based on quantitative data are needed. JArDinS is a quasi-experimental study aimed at assessing the impact of community garden participation in the adoption of more sustainable lifestyles. Materials and Methods Gardeners starting gardening in a community garden in Montpellier (France) were recruited in 2018. Volunteers with no experience in community gardening and matched for age range, gender, household income and household composition were recruited in a control group. A recruitment goal of 80 participants per group was determined to detect a 30% increase in F&V supply in the gardeners group. Participant were issued with three tools: a Food Supply Dairy to collect data on monthly household’s food supply, a triaxial accelerometer to measure physical activity and an online questionnaire on mental and social health, sensitivity to food waste, and connection with nature. Measures have been collected at baseline and will be repeated 12 months later. Data collected are examined conjointly to assess the sustainability of lifestyles in its social/health, environmental and economic dimensions. Change of outcomes after 1 year will be compared between the natural experiment and the control groups, to evaluate the effect of access to a community garden on the sustainability of lifestyles. Results A final number of 77 participants per group were enrolled at baseline, which is 4% less the original recruitment goal. Baseline data for the natural experiment group and the control group are currently being analysed and will be presented. Discussion This study will provide valuable information about the potential of community gardens to favor sustainable lifestyles, based on a robust quasi-experimental design allowing causality evaluation. Findings could help developing policies toward more sustainable urban planning favoring both human and environmental health. Key messages For the first time, the JArDinS study will allow testing, the impact of community gardens on the sustainability of lifestyles. Results will help orient urban planning decisions towards healthier options.

Selection and segregation of herds for a valuable milk trait

Abstract Dairy processors are seeking to exploit the natural variation in milk components at the farm level to produce high margin niche products. On-farm segregation of milk within or between herds and enhancement of desired traits are mechanisms to increase supply. A simulation modelling approach was used to investigate the genetic effects of breeding and segregating cows for an illustrative milk attribute, milk fat colour. This trait is valuable to New Zealand seasonal supply dairy farmers. Changes in production and the proportion of cows producing “white” (lighter milk fat colour) milk were predicted for a 20 year period for several selection strategies. Genetic gains relative to the status quo were predicted using sires from a small breeding scheme selecting for milk fat colour and yield. It took 18 years or more of continuous breeding for the whole herd to produce “white” milk, although not necessarily over the whole of the lactation under a pasture-based farming system. Selection on colour reduced yield of other valuable traits relative to the status quo herd. Initial selection of cows, reproduction and management strategies can all speed up progress but add cost. Premiums for segregated milks need to compensate owners for transition costs, production losses (if any) relative to the status quo, and the risk associated with long term change.

Milk harvesting and cow factors influencing seasonal variation in the levels of free fatty acids in milk from Waikato dairy herds

Free fatty acids (FFA) occur naturally in milk and, under certain on‐farm conditions, concentrations increase, affecting the flavour, processing efficiency, and shelf‐life of dairy products. To obtain some understanding of these, FFA concentration was determined in silo milk samples collected from seasonal supply dairy farms in Waikato, New Zealand during the 1997/98 and 1998/99 dairying seasons. Selected farms represented the major dairy systems: 25 farms had continuous (rotary) milking systems and 25 farms had batch (herringbone) milking systems. Four of the herringbone dairies had milk‐harvesting systems that eliminated the air‐milk interface (Ruakura Milk Harvester; RMH). FFA concentrations were assessed every 2 weeks in bulk milk samples collected from the farm silo. Concentrations of FFA were lowest in spring (early‐lactation) and highest in summer and autumn (mid‐late lactation). The type of dairy design (herringbone versus rotary) had no association with FFA concentrations, but the four herds milked by the RMH system tended to produce milk with lower (P < 0.10) FFA concentrations during summer and autumn 1998/99. A number of factors were associated with increased FFA concentrations: type of milking system, milk yield, somatic cell count (SCC), milk composition, and stage of lactation. Bacterial infection as identified by SCC and the elimination of the air‐milk interface during milk harvesting (RMH) had possibly major influences on FFA concentrations.

Successful North Canterbury dairy conversion with quality pasture of nil endophyte ryegrass

I have been farming all my working life in partnership with my brother Graeme in a family company known as V.Q. Sutton &amp; Sons Ltd. While I managed our town supply dairy farm in Redwood Valley, west of Nelson, Graeme managed our sheep and beef farm at Kikiwa, near Nelson Lakes. With the impending deregulation of the town supply industry and the growing realisation that our assets were held in high-value Nelson land, we diversified into horticulture, establishing 5 ha of kiwifruit, but we soon realised our strengths were in grassland farming.

Management of summer feed deficits on three high-performing dairy farms in the Manawatu

New Zealand dairy farmers rely on pasture grazed in situ to feed their herds. Summer is the most difficult period to manage because pasture production is usually highly variable and, in most years, less than herd requirements. Dairy farmers can use a range of options (e.g., summer forage crops, silage) to minimise the impact of both variable and inadequate summer feed supply. Much has been written about recommended procedures for planning and monitoring pasture-based systems, but there is little documentation on the processes actually used by New Zealand dairy farmers. To this end the summer management processes of three high-performing Manawatu seasonal supply dairy farmers were studied over 4 years. The farmers used management systems based on their experience. A range of simple techniques was used to identify potential feed deficits. The farmers then used a set of decision rules to select the best option or combination of options to overcome feed deficits. The study highlighted the potential benefits that could accrue from integrating farmer knowledge with scientific knowledge. Keywords: dairy farmers, decision-making, farmer knowledge, monitoring, summer management

Conversion of an eastern Southland sheep farm to factory supply dairy pasture: changes and implications for production

The Kleyngelds sharemilk a 135 hectare dairy farmm for Tasman Agricultme, converted from sheep in 1990. 350 cows are wintered with total production being 41 800 kg milkfat (90/W), 54 000 kg (91/92), and projected 92/93,57 000 kg. One third of the farm is in newer ryegrass/clover, the remaining mainly browntop. Grass grown and grazed is recorded, so paddock performance can be monitored. The major result is variation in growth, 1 l- 3 tonnes/DM. A grazing round of approximately 26 days suits all pastures for best performance. A balance is created between under- andovergrazing. Pasture is grazed to a base level of 1400 kg/ha/DM, to ensure quick regrowth but no loss of quality. Regrassing is the major emphasis -- approximately lo-20 hectares are done a season. Ryegrasses and clover are used at 23 kg/ha. Pasture is sprayed and direct drilled with care taken in grazing for first season. Fertiliser complements regrassing. Over the last two years 400 kg/ha 15% potassic super was applied, this season 600 kg/ha were applied. Nitrogen is used strategically from.late winter to autumn according to soil temperature over the whole farm. There are flow on effects through winter and early spring. Limiting factors to conversion are management, fertility and grasses. Planning is needed to utilise resources for best returns. Keywords dairy conversion, fertiliser, regrassing, sheep farm, dairy farm

Phosphorus supplementation of lactating dairy cattle on a Northland farm

Forty-eight Friesian or Friesian-X factory supply dairy cows were divided into two groups. Group 1 received a supplement of sodiumtripolyphosphate (TPP, 25g P, 25g Na/cow/day), and group 2 a supplement of sodium chloride (25g Na/cow/day). Supplementation began at peak lactation, when the mean serum inorganic phosphorus (Pi) of all cows was 1.13 mmol/l. After four weeks, group 2 changed from NaCl to dicalcium phosphate supplementation (25g P/cow/day). Serum Pi and yields of milk, butterfat and protein were measured before, during and after supplementation. Pasture availability was assessed and P and Ca contents in pasture and the Pi content in milk were also determined. Supplementation raised serum Pi from 1.30 mmol/l (NaCI) to 1.42 mmol/l (TPP, P<0.05) but when dicalcium phosphate replaced NaCl the difference between groups disappeared (P>0.05). P supplementation had no effect on any milk parameter. Pre-grazing pasture mass above estimated grazing height averaged 2260 kg DM and contained >or=0.39 per cent P. It is concluded that a herd mean serum Pi concentration of around 1.2-1.3 mmol/l imposes no limitation to dairy production around the period of peak lactation of grazing dairy cattle.

A survey of the phosphorus and calcium contents of pastures and the serum inorganic phosphorus and calcium contents of cows on four Manawatu dairy farms

Serum inorganic phosphorus (Pi) and calcium (Ca) concentrations were assessed in 20 cows on each of four Manawatu factory supply dairy farms. Blood was taken from each cow before calving and at six-week intervals during lactation. Bleeding coincided with herd testing. Herds of Friesian or Friesian X cows and Jersey or Jersey X cows were compared on adjacent farms on a Central Yellow-brown Sand and on adjacent farms on a Peat Loam overlying a Central Yellow-brown Earth soil. Pasture mass and composition were estimated to grazing height in the next two paddocks to be grazed in the rotation. Mean serum Pi concentration was higher in cows on sandy soils (1.55 mmol Pi/l than in cows on the peat loam (1.34 mmol Pi/l (P<0.001). Concentrations were highest before calving (1.69 mmol Pi/l) but fell to low levels at peak lactation (1.17mmol Pi/l when 70% of cows were below the minima of the 'normal range', and during the drought (1.29 mmol Pi/l. Pasture phosphorus (P) concentrations were adequate to support cow nutrition for lactation (>0.33% DM, ad lib. feeding) until the summer drought when low herbage mass would have restricted milk production. Serum Ca was adequate for lactating cows and changed little between months or between cows (mean 2.12 mmol Ca/l). No metabolic disorders relating to mineral deficiencies were observed. It appears that serum Pi in a high proportion of cows falls below the normal range during peak lactation without cows displaying clinical deficiency symptoms or a depression in butterfat production.

Economics of a dry-cow anthelmintic drenching programme for dairy cows in New Zealand. Part 1. Overall response in 47 herds

Trials were conducted on 47 seasonal supply dairy farms (>5500 cows) to assess the economics of a dry-cow anthelmintic drenching programme. The programme was administered during the autumn/winter of 1983 and consisted of two treatments, the first shortly after drying off (late April-early June) and the second shortly before calving (mid-July-late August). The effects of the programme on the body condition of cows over winter and their subsequent milk production and reproductive performance were assessed. Overall, the treatment did not result in a worthwhile improvement in cow condition over winter. However, there was a small, but significant overall increase in milk production (2.24 kg milkfat/cow/lactation = 51.5 1 milk; P < 0.01). Young cows (3 years old) did not respond significantly better than mature cows, but high quality cows (as assessed on the basis of the previous season's milk production) responded significantly better than those of poorer quality. The pre-calving condition of cows did not significantly influence the magnitude of their response. Calving data for the year following the trials indicated that conception rates and time of conception were unaffected by the drench programme. At prices prevailing at the time of the trials, the programme proved to be only marginally economic overall (∼ 1 kg milkfat/cow was required simply to cover the cost of the anthelmintic used). However, levels of response in the individual herds involved varied considerably.

Economics of a dry-cow anthelmintic drenching programme for dairy cows in New Zealand. Part 2. Influence of management factors and other herd characteristics on the level of response

The results of a series of trials conducted on 47 seasonal supply dairy farms in the southern North Island of New Zealand, which indicated a statistically significant overall production response of 2.24 kg milkfat/cow/lactation following a 2-treatment dry-cow anthelmintic drenching programme (Bisset et al., 1987), were subjected to further analyses in an attempt to identify any management factors or herd characteristics which may have influenced the levels of production response to treatment in individual herds. The management factors examined included calf drenching practices, types of grazing system, mean pre-calving condition of the herds, and ‘nutritional status’ of the herds over the milking season. The influence of herd quality, herd size and geographical location were also examined. Considered separately, only calf drenching practice had a significant influence on the level of herd response to treatment. Increases in milkfat production/cow due to the treatment programme were significantly greater ( P<0.05, t-test) on farms where calves had received a minimal number of drench treatments (⩽2) between weaning and the end of March (mid-autumn) (+5.32 kg/cow/lactation, P<0.01) (=108.2 l milk), than on farms where calves had received regular 3–4 weekly treatments over the same period (+0.42 kg/cow/lactation, N.S.). While none of the other factors, considered in isolation, appeared to significantly influence the production response of herds, observations on possible interactive effects suggested that the grazing system employed was probably of importance in so far as it determined the level of exposure of cows to calf-contaminated pasture. Thus, the greatest mean response to the treatment programme occurred in herds where cows were overwintered on areas grazed during the milking season by calves which had received ⩽2 drench treatments from weaning until the end of March (+5.95 kg milkfat/cow/lactation, P<0.01).

Selenium response in dairy cattle

Abstract Extract Madam:- We wish to report the findings of selenium (Se) response trials in three Taranaki factory supply dairy herds.

A survey of the phosphorus content of pastures and the serum inorganic phosphorus content of dairy cows

Serum inorganic phosphorus (Pi) concentration of 20 cows in each of ten factory supply dairy herds was assessed at monthly or two-monthly intervals during the 198243 lactation. Pasture on offer was ranked low, medium or high and the phosphorus (P) content assessed monthly on all farms from the two paddocks to be grazed next in the rotation. The mean serum Pi concentration was high (1.98 mmol/l) prior to calving but fell to low levels at peak lactation (1.28 mmol/l) and again during the drought (1.28-1.38 mmol/l) in January, February and March. Individual cows had Pi levels as low as 0.32 mmol/l. Herds on Northern Yellow-brown Earths had higher Pi levels than herds predominantly on Brown Granular Loams (P<0.01). There were differences between cows within herds (P<0.01) and Pi levels declined with cow age (P<0.01). Pasture P content was above minimum requirements for lactating cows (0.33% DM; with ad lib. feeding) from July through October but below requirements in most pastures from December through April, when pasture availability also limited production. The P content in pasture was unrelated to either its grass or legume content, but was higher in pastures given a medium or high DM ranking (P<0.05). The possibility of increasing dairy production with P supplementation in spring is discussed.

Phosphorus deficiency in a dairy herd

Phosphorus deficiency was diagnosed in a 90 cow seasonal supply dairy herd which showed low milk production, ill-thrift, infertility and osteophagia. Serum inorganic phosphorus and pasture phosphorus levels were low, pasture Ca:P ratios high and soil phosphorus levels very low; the soil phosphate retention value was 96%. The deficiency, which had probably existed for several years, was considered to be due to inadequate annual phosphate fertiliser applications on a high phosphate retaining soil. Phosphorus deficiency may have been exacerbated by the application of lime without phosphate several months before the onset of severe clinical disease. The finding of low sodium levels in pasture samples suggested that sodium deficiency may have co-existed and contributed to the clinical picture. Treatment, comprising bone flour dusting of pasture, water trough supplementation and phosphorus-containing injections, appeared to induce ovarian activity in anoestrous cows and suppress osteophagia, though controlled treatment trials were not performed. No improvement was noted in milk production or cow condition. Increased annual super-phosphate and reduced potassium applications were recommended, together with the monitoring of pasture and soil macro elements and serum phosphorus levels. A decision on whether to supplement with sodium would be based on the results of pasture monitoring, since a direct animal test is not currently available. It is suggested that phosphorus deficiency may not be uncommon in dairy herds in some North Island districts; based on the present case, the decline in New Zealand superphosphate quality in the 1970's and recently published data which has shown a high proportion of pasture phosphorus deficient sites in some North Island areas.

Pre-mating injection of an analogue of gonadotrophin-releasing hormone (GnRH) and pregnancy rates to first insemination

Two hundred and ninety two dairy cows received a subcutaneous injection of a 2.5 ml solution containing 10 microg GnRH-analogue (Receptal, Hoechst A.G.) 0-6 hours before insemination, while 284 cows acting as controls were injected with 2.5 ml of sterile pyrogen-free water at the same time. The two groups, the treated and the control, were formed by matching (pairing) each oestrous cow with another on the basis of interval from calving to first mating, condition score, and age on the day of first mating after calving. The cows were in 3 factory supply dairy herds, which were visited daily during the first 3 weeks of the mating season. All the cows presented for mating each day were inseminated by the same technician using 0.5 ml of ambient-temperature semen containing 2 million spermatozoa per insemination. The semen used on any particular day originated from one ejaculate of one bull (same batch number). The cows were manually examined for pregnancy 2 to 3 months after their first insemination. A similar response was seen in all three herds irrespective of the interval from calving to mating. First mating pregnancy rates were 9.3% higher in the Receptal-treated cows than in the control group (P = 0.025). It is suggested that Receptal may have a beneficial effect on the pregnancy rate of cows that have recently ovulated as well as on those having delayed ovulation.

A survey of pasture silage making on factory supply dairy farms in the Central Waikato 1977–78

Abstract Pasture silage making practices on 89 factory supply dairy farms in the Central Waikato were surveyed. Average farm size was 61.7 ha of which 59.7 ha was effectively farmed with a stocking rate of 2.50 cows per ha. On average silage was made from 8.7 ha pasture (15% of the effective area) yielding 23 t fresh matter per ha (4.3 t dry matter (DM)), i.e., 0.25 t DM per cow. Silage was normally made about the second week of November from paddocks closed for 7–8 weeks and was precut for wilting on 78% of farms. Farmers were generally unaware why or how and to what DM content silage should be wilted. Although plastic sheeting was used to cover 60% of stacks, only 17% were covered immediately and only 26% were judged to be adequately airtight. Silage was usually made with the intention of feeding out during drought. Machinery used to make silage, method of ensiling, and method of feeding out are described. The timing of feeding out silage and the use of a crop in association with silage making are discu...

Planned animal health and production service (PAHAPS) in New Zealand dairy herds

New Zealand dairy farming is a low cost grassland operation. It is based primarily on a seasonal system of management whereby the calving pattern of the herd is concentrated so that maximum milk production coincides with the greatest pasture production for grazing. While techniques for planned animal health and production systems had been developed in other countries, modifications were likely to be required if they were to be applied to this production system. A feasibility study was carried out on a group of 18 Waikato seasonal supply dairy farms; the results of this study are presented in this paper.