@article {3672,
	title = {Use of organic waste streams to reduce the carbon footprint of New Zealand milk},
	journal = {New Zealand Journal of Animal Science and Production},
	volume = {82},
	year = {2022},
	month = {01/2022},
	pages = {88-92},
	address = {Online},
	abstract = {<p>Life Cycle Assessment was undertaken to determine the impact of replacing purchased feeds and nitrogen fertiliser with New Zealand-sourced organic waste streams, on the cradle-to-farm-gate carbon footprint of a dairy farm. Five scenarios were assessed: 1) average New Zealand dairy farm, 2) supplementary feeds sourced from food waste, 3) mineral fertiliser replaced with chicken manure, 4) mineral fertiliser replaced with pig manure, 5) a combination of scenario 2 and 3. Diets in each scenario had the same total metabolisable energy and nitrogen content. Organic fertiliser was applied to ensure the same total nitrogen application per hectare. Replacing purchased feeds with waste from the food industry reduced the carbon footprint by 9\%, while replacing synthetic nitrogen fertiliser with chicken or pig manure resulted in a reduction of 1\%. Although this has shown the potential to reduce the carbon footprint of New Zealand milk while also reducing reliance on mineral fertilisers and imported feed, further work is required to determine feasibility and broader impacts.</p>
},
	issn = {1176-5283},
	author = {Burggraaf VT and Mazzetto AM}
}
@article {3672,
	title = {Grazing behaviour of young cattle around faecal pats},
	journal = {New Zealand Journal of Animal Science and Production},
	volume = {81},
	year = {2021},
	month = {01/2022},
	pages = {63-67},
	address = {Online},
	abstract = {Young Holstein Friesian bulls grazed four mixed-contour paddocks for a duration of three days on ten occasions between December 2002 and March 2004. For the first seven grazing events, five faecal pats on both easy- (<25o) and steep-contoured land in each paddock were selected for monitoring herbage removal during the subsequent four to five grazing events. After each day of grazing, pasture height was measured at 5-cm intervals for 50 cm from the centre of each pat. The decrease in pasture height was converted to estimates of herbage dry matter removal. For the first three grazing events following pat deposition, avoidance of grazing herbage around pats was greatest on the first day of the three-day grazing duration. The mean distance of grazing from the centre of the pats was 21, 14, 10 and 7 cm for the first to fourth grazing events following deposition. Avoidance was greatest around pats that were deposited in late spring/early summer with little difference occurring between pats located on easy or steep land. Increased grazing pressure appeared to override the natural behaviour of young cattle to avoid grazing close to faecal pats. Grazing management of young cattle should ensure residuals of at least 1500 kg DM/ha in order to minimise the grazing of herbage surrounding faecal-pat areas which are highly contaminated with parasite larvae.
Keywords: cattle; grazing behaviour; faecal pats; cattle parasites},
	issn = {1176-5283},
	author = {Boom CJ and Sheath GW and Burggraaf VT}
}
@article {3672,
	title = {BRIEF COMMUNICATION: A case study of the effects of diet and winter management on dairy production, profit and nitrate leaching in Rotorua},
	journal = {New Zealand Journal of Animal Science and Production},
	volume = {79},
	year = {2019},
	month = {07/2019},
	pages = {71-73},
	address = {Palmerston North},
	abstract = {Feed and winter management options were modelled for a dairy farm and its adjoining support land in the Lake Rotorua catchment. The dairy farm grew turnips, fodder beet and oats, with non-lactating cows grazing on the dry-stock unit on pasture, kale and fodder beet. Scenarios investigated were: removing crops from the dairy farm whilst either A) reducing stocking rates by 5\%; B) feeding additional palm kernel expeller (PKE); C) replacing crops, PKE and pasture silage with purchased maize grain and maize silage; or D) grazing non-lactating cows on the dairy farm and reducing stocking rates by 17\%. Using a milk price of $6.00/kg MS, D was the only scenario that increased profitability of the dairy farm (7\%). Compared to the base scenario, nitrate leaching on the dairy farm increased for scenario D and decreased for scenarios A, B and C. When including the dry-stock unit, total N leaching was reduced by 5, 0, 13 and 15\%, for A, B, C and D, respectively, compared to the base farm. These results reiterate the importance of investigating the impact of off-farm winter grazing in nitrogen-sensitive catchments.},
	issn = {1176-5283},
	author = {Burggraaf VT and Rennie GR and Edwards P and Pinxterhuis I}
}
@conference {69477,
	title = {Simulated impacts of increased nitrogen retention in dairy cows on nitrate leaching from grazed pasture},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {70},
	year = {2010},
	month = {Jun},
	pages = {86-87},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Palmerston North},
	abstract = {The intensification of grazing land has increased the amount of nitrogen (N) entering waterways, reducing their quality and clarity. Between 60 and 90\% of the N ingested by grazing cattle is excreted in urine and dung (Haynes \& Williams, 1993), providing the major source of nitrate leached from grazed pasture. Reducing the N content of urine can therefore have a major impact on nitrate leaching, which can be achieved by reducing dietary N or improving N partitioning in the animal. Some  techniques that improve N partitioning have been evaluated. These include dietary manipulation and the use of metabolism modifiers (Di \& Cameron, 2000).},
	issn = {1176-5283},
	author = {de Castro J and Bryant JR and Burggraaf VT}
}
@conference {41807,
	title = {Effect of dietary protein on liveweight gain in parasitised cows},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {68},
	year = {2008},
	month = {Jan},
	pages = {113-116},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Brisbane, Australia},
	abstract = {The interaction between parasitism and crude protein (CP) nutrition on calf liveweight gain (LWG) was investigated. One hundred and twelve calves were either administered 21,000 parasite larvae (73\% Cooperia oncophora, 16\% Ostertagia ostertagi, 11\% Trichostrongylus axei) twice per week or drenched fortnightly with anthelmintic for 12 weeks. Calves grazed ryegrass pastures and received 40\% of their diet as either low (15\% CP) or high (26\% CP) protein pellets. Half of the calves switched diets after six weeks. All treatments averaged a liveweight gain of at least 1 kg/d. After 12 weeks non-parasitised calves were 13 (standard error of difference (SED 2.0)) kg heavier than parasitised calves (P <0.001), and calves fed a high protein supplement were 12 (SED 2.8) kg heavier than those fed low protein supplement (P <0.001). There was no interaction between diet and parasitism (P = 0.74). Subsequentlycalves grazed together for a further 12 weeks with no supplements or parasite dosing. The liveweight advantage of the high protein supplement was lost, while non-parasitised calves maintained a liveweight advantage of 15 (SED 4.9) kg (P <0.01). While protein supplementation did not affect faecal egg count or blood pepsinogen it has the potential to improve LWG with less reliance on anthelmintics under field conditions.},
	issn = {1176-5283},
	author = {Burggraaf VT and Puha MR and Adler AA}
}
@conference {41983,
	title = {A dynamic model incorporating dietary protein for predicting liveweight gain of parasitised grazing lambs},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {67},
	year = {2007},
	month = {Jan},
	pages = {220-225},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Wanaka},
	abstract = {Internal parasites are one of the major constraints toliveweight gain (LWG) in young grazing ruminants. However, even in parasite-free animals, diets low in crude protein can constrain LWG from values expected on the basis of metabolisable energy intake alone. We investigate the impact of protein supplementation in overcoming reduced growth rates of parasitised animals. This was done via a dynamic model which assumes increased maintenance requirements (immune requirements, increased cell turnover and mucous production) in parasitised animals. A key output from the model is LWG over an extended grazing period. We calibrated and validated the model using published data from an indoor feeding experiment in which trickle-infected lambs were fed for 20 weeks on three diets providing different amounts of metabolisable protein. The mean liveweight and worm burden predicted from the model compared well with experimental data. Such models will prove useful in designing supplementation strategies for grazing lambs where anthelmintic control of parasites is not a management option.},
	issn = {1176-5283},
	author = {Louie K and Burggraaf VT and Pacheco D}
}
@conference {41695,
	title = {Response of calves to different levels of mixed species gastrointestinal parasite infection},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {67},
	year = {2007},
	month = {Jan},
	pages = {23-27},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Wanaka},
	abstract = {The effect of different levels of parasite infection was studied in 5-month old calves. Eighty-four calves were dosed with 0, 1000, 2000, 4000, 7000 or 10000 parasite larvae (L3) per day for 6 weeks (90\% Cooperia, 10\% other species), or were drenched 3-weekly, whilst grazing in one mob. Worm burdens were then determined in 3 calves per treatment. The remaining calves then grazed together for 11 weeks to determine carryover effects, during which they were all drenched at weeks 5 and 9. At the end of L3 dosing, there were no liveweight differences, but by week 5 of the carryover period, calves receiving 10000 L3 per day were 12 kg lighter than drenched or 0 L3 calves (P<0.05). This difference was maintained for the rest of the experiment.  Cooperiaburdens (76000/calf) in 10000 L3 calves were at least double those on all other treatments (P<0.001). There was no relationship between L3 dose and worm burden for the other parasite species, or L3 dose and faecal egg count. This experiment has shown that for calves dosed with less than 10000 L3 per day, drenching does not increase liveweight gain when the parasite larvae are 90\% Cooperia.},
	issn = {1176-5283},
	author = {Burggraaf VT and Puha MR}
}
@conference {41135,
	title = {Milk production from perennial ryegrass pastures containing different levels of endophyte},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {59},
	year = {1999},
	month = {Jan},
	pages = {258-262},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {These experiments aimed to compare milk production in spring and autumn from perennial ryegrass pastures containing either
low (L) (<10\%) or high (H) levels of endophyte infection at two pasture allowances.  In October 1997 milk yield was higher (P<0.05) from L compared with H endophyte (15.1 v 14.4 kg/cow/day), similarly for fat yield (0.95 v 0.9 kg/cow/day), and milksolids (MS) (1.53 v 1.46 kg/cow/day), but not protein yield.  In October 1998 there was no effect of endophyte level on milk, fat, protein and MS yield.  In March 1998 milk yield was higher (P<0.001) from H compared to L endophyte (8.5 v 7.4 kg/cow/day), similarly for fat yield (0.53 v 0.48 kg/cow/day), protein yield (0.35 v 0.34 kg/cow/day) and MS yield (0.89 v 0.81 kg/cow/day).  No carryover effects were recorded on milk yield or composition in any period.},
	issn = {1176-5283},
	author = {Clark DA and Thom ER and Waugh CD and Burggraaf VT}
}
