@conference {40640,
	title = {Farm management implications of a seasonal price differential for factory supply milk production},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {54},
	year = {1994},
	month = {Jan},
	pages = {383-388},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {A number of New Zealand dairy companies have proposed a differential  
pricing scheme that would discount the price paid for "peak milk" and provide  
a premium for milk supplied "off peak".  A linear programming model was  
developed to analyse the on-farm impact of a differential milk pricing scheme.   
The differential pricing scheme used in the study was based on a dairy  
company where farmers supplied 30\% of total milk during the  
October/November peak and 70\% during the off-peak period (peak-to-shoulder  
ratio of 30:70).  The impact of three price differentials of $0.82/kg MS,  
$1.63/kg MS and $2.45/kg MS between peak and off-peak milk was analysed.   
The results showed that if the case study farmer made no management changes  
to his system, there would be little change in the farm gross margin per hectare  
under a differential pricing scheme, provided the farm had a peak-to-shoulder  
ratio close to that used by the dairy company to set the price differential.   
However, returns declined by $182/ha, if the farm peak-to-shoulder ratio was  
40:60 and increased by $185/ha if the ratio was 20:80.  A price differential of  
at least $1.71/kg milksolids ($3.00/kg MF) between peak and shoulder milk, was  
required to reduce peak milk production significantly.  As the price differential  
increased, the LP model selected solutions that reduced both total milk  
production and the ratio of peak-to-shoulder milk.  Management changes  
selected to modify the pattern of milk production included; a reduction in  
stocking rate, a shift to an earlier calving date (and then a split calving),  
an increased lactation length, higher cow condition at calving and greater use  
of supplements. 
 },
	issn = {1176-5283},
	author = {Gray DI and Yuretich PA and Lynch GA}
}
@conference {40471,
	title = {Drying off management and the use of management aids on seasonal supply dairy farms},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {53},
	year = {1993},
	month = {Jan},
	pages = {127-132},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {No abstract supplied.},
	issn = {1176-5283},
	author = {Parker WJ and Gray DI and Lockhart JC and Lynch GA and Todd EAG}
}
@conference {40500,
	title = {Effects of rumensin anti-bloat capsules on plasma magnesium concentration and aspects of health and performance of pastured dairy cows},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {53},
	year = {1993},
	month = {Jan},
	pages = {247-250},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {A total of 134 ewe lambs born in 1991 from the Ruakura "Kamo" out- of-season breeding flock were run with harnessed vasectomised rams from weaning and inspected weekly for onset of puberty and subsequent oestrus activity. The breeding values for date of lambing (BV) for these animals were calculated from a pedigree and performance database. Multiple regression analysis were performed to determine the value of factors associated with hogget oestrus for predicting BV. While all the factors analysed, date of puberty, age and weight at puberty and number of subsequent oestrus cycles, had significant effects, none were as useful a predictor as date of birth(Bday).  Season of birth (autumn vs spring) also exerted considerable influence on date of first tup and number of cycles. The results indicate that the best method of selection at present is that based on date of birth. Further research is needed to understand the interaction between season of birth and BV as they influence the onset of puberty.},
	issn = {1176-5283},
	author = {Wilson GF and Lynch GA and Van Der Wel C}
}
@conference {40364,
	title = {A conceptual framework for an expert system to improve drying off decisions on seasonal supply dairy farms - Brief Communication},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {52},
	year = {1992},
	month = {Jan},
	pages = {11-12},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Forty Border Leicester (BL) and forty-eight Dorset Down (DD)  ewe hoggets (7.5mo) that had been farmed together were scanned using a  real-time ultrasound machine, at six sites with one muscle depth (B) and  five subcutaneous fat depth measurements (R - tissue depth over fifth  rib, C - backfat over last rib, GR, L - backfat over last lumbar  vertebrae, T - fat over tail) being taken. Comparisons of tissue ratios  (individual fat depth divided by B) were used to characterise  subcutaneous fat distribution. From these ratios it was found that the  DD had 9\%, 10\% and 6\% greater ratios at R, L and T respectively, and 7\%  lower ratios at C and GR. Breed differences at R, GR and T were  significant (P<0.05). It was concluded that true genetic differences in  subcutaneous fat distribution existed between the genotypes studied.  These findings have implications for carcass classification, for  breeding programmes for lean growth, and for comparisons of the fatness  of different genotypes.  },
	issn = {1176-5283},
	author = {Gray DI and Lynch GA and Lockhart JC and Parker WJ and Todd EG and Brookes IM}
}
@conference {40309,
	title = {The effects of once daily milking as a management practice in late lactation},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {51},
	year = {1991},
	month = {Jan},
	pages = {191-196},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Five goats were milked hourly for 43 h on two occasions, on one  occasion receiving injections of growth hormone (GH; 15 mg S.C.) after 4  and 28 h of the milking period and on the other occasion were untreated.  Blood samples were taken before each milking, the latter facilitated by  intravenous injection of oxytocin (100 m i.u.).   Milk yield began to rise 4-5 h after the injection of GH and continued  to rise for a further 8-9 h until a level of production 18\% above the  pre-treatment yield was achieved. Following the second injection of GH  the yield increment was reduced such that by the end of the experiment  the yield increase was 24\%. In one goat the milk yield response was not  sustained and these data were excluded from the above calculations.   Plasma insulin-like growth factor-I (IGF-I) and insulin concentrations  increased in a similar time-course to the change in milk yield  following GH treatment but were relatively constant in control  experiments. IGF-I and insulin content of plasma was approximately  doubled by GH treatment by the end of these experiments.  },
	issn = {1176-5283},
	author = {Lynch GA and Hunt ME and MacKenzie DDS}
}
@conference {40335,
	title = {Non-milk constituents in replacers for calf rearing},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {51},
	year = {1991},
	month = {Jan},
	pages = {323-326},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {This study was carried out to investigate central nervous system  pathways which may be involved in the depression of food intake  exhibited by parasitised lambs.   Ten lambs with intake depression (c.20\%; p<0.05); as a result of chronic  infection with 4000 T.colubriformis larvae/day together with 10  non-infected animals were used in a factorially designed experiment.  The factors were a 24 h fast or no fasting followed by; saline solution  (control), or 0.6 mg/kg brotizolam (blocks satiety signals at the  ventromedial hypothalamus), or 0.125 mg/kg of naloxone (an opioid  antagonist), all in a 2 ml volume given i.v. immediately prior to  feeding.   Trickle infection depressed mean daily intake by 20\% (p<0.05), likewise  short term intake was depressed by infection (p<0.05). Fasting  stimulated both short term and daily intake by approximately 100\%  (p<0.001) and 12\% (p<0.05) respectively. Naloxone depressed cumulative  intake for up to 2 h (p<0.01 - p<0.001) while brotizolam stimulated  intake at both 60 and 120 minutes (p<0.001).   These results show that opioid signals stimulate food intake in lambs  and that fasting will overcome the effects of parasitism on appetite in  the short term. A lack of opioid signals may be a factor in parasite  induced food intake depression.  },
	issn = {1176-5283},
	author = {Wilson GF and Brookes IM and Lynch GA and Billington AC}
}
@conference {40316,
	title = {Plasma hormone concentrations in pasture-fed Friesian cows treated with recombinantly-derived bovine somatotropin (bST)},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {51},
	year = {1991},
	month = {Jan},
	pages = {235-238},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Dairy farmers often debate the importance of liveweight of  rising 2 year old heifers and the value of various heifer wintering  systems on subsequent production. Lifetime performance of all dairy  cows born on the Taranaki Agricultural Research Station have been  recorded since 1978 on a computerised data base. This data base was  utilised to determine the liveweight gain of heifers and cows over  winter and the effects of this on production in the following season.   Initial analysis of the data showed a significant (P<0.01) age effect on  winter liveweight gain within a mixed age herd of cows. The average  liveweight gain over eight years of the older cows (4 yr +) was 3 times  that of the rising 2 year olds. Further analysis showed a significant  (P<0.05) age effect on the relationship between liveweight at calving  and production of milkfat in the following season. Higher liveweight at  calving resulted in a greater increase in production for 2 year olds  than for older cattle. The conclusion to be drawn from this is that  wintering rising 2 yea old heifers separately from older cows to achieve  higher liveweight may have beneficial effects on the following seasons  production.   A field trial in winter 1990 to test this assumption showed the winter  liveweight gain of rising 2 year old heifers and mature cows, offered  the same herbage allowance, was significantly (P<0.01) higher when  wintered separately than wintered as a mixed age herd. Subsequent milk  solids production from the two-wintering systems was the same despite  different liveweight at calving. Aspects of herd behaviour were  suggested as the cause of the nil response.  },
	issn = {1176-5283},
	author = {McCutcheon SN and Hoogendoorn CJ and Lynch GA and Wickham BW and Breier BH and Gluckman PD}
}
