Conference Papers
Permanent URI for this collectionhttps://mro.massey.ac.nz/handle/10179/7616
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Item A review of the use of chicory plantain red clover and white clover in a sward mix for increased sheep and beef production(NZ Grassland Association, 2015) Cranston LM; Kenyon PR; Morris ST; Kemp PDMany farmers are sowing mixed swards containing chicory (Cichorium intybus), plantain (Plantago lanceolata), red clover (Trifolium pratense) and white clover (T. repens) (hereafter termed herb and clover mix). This herb and clover mix has comparable annual dry matter (DM) production to perennial ryegrass white clover pasture (rye/wc), however, it has a different pattern of growth, producing more DM during summer and autumn. The herb and clover mix also has a higher nutritive value and is able to support greater rates of animal production, especially over summer, than rye/ wc in both sheep and cattle. The herb and clover mix is most suited to a rotational grazing interval of 3–4 weeks to an 8 cm residual height, with no winter grazing. When managed appropriately the herb and clover mix is able to persist for at least 2 years and up to 5 years under both sheep and cattle grazing.Item Days to calving and intercalving interval in beef and dairy-beef crossbred cowsMorris ST; Hickson RE; Martin NP; Kenyon PROne important attribute of a beef-breeding cow is the ability to wean a calf every year. Furthermore, an earlierborn calf is likely to be heavier at weaning and its dam has more opportunity to conceive again during the following breeding season. In a spring-calving system under the seasonal pastoral-grazing system in New Zealand, a 365- day intercalving interval is desirable. A normal gestation length is 280 days leaving 85 days for a cow to resume oestrous cycles and conceive again to maintain the 365- day calving interval. Literature estimates of the interval between calving and the first oestrous cycle post-calving are 53-82 days for mixed-aged beef-breeding cows and 81-95 days for first-lactation beef-breeding cows (Hickson et al. 2012; Knight & Nicoll 1978; Morris et al. 1978; Smeaton et al. 1986), indicating that a 365-day calving interval is difficult to maintain. An alternative reproductive performance measure to intercalving interval, and favoured in naturally mated beefcow herds, is days to calving, that is defined as the number of days from the start of joining to the day of calving. Days to calving has become the standard fertility trait for genetic evaluation (Meyer et al. 1990; 1991; Johnston & Bunter 1996). A study was conducted to investigate the effects of breed group, year of calving and conception cycle on intercalving intervals and days to calving in straight-bred Angus and Angus-cross-Friesian, Angus-cross-Jersey and Angus-cross-Kiwicross cows from first mating as heifers through to their sixth calving.
