@conference {40408,
	title = {The breeding season of pubertal red deer hinds},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {52},
	year = {1992},
	month = {Jan},
	pages = {183-186},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {This paper summarises a series of experiments near Rotorua in  which the liveweight changes of sheep grazed on pasture under Pinus  Radiata was measured. In general terms sheep performance was lower as  the tree stocking increased. Long term experiments have shown that  under continuous grazing, sheep performance declines with increased tree  stocking from as early as tree age 5 years. Feed allowance experiments  indicated there may be a general decline in the feed value of pasture  growing under Pinus Radiata. The effects were minor at tree stockings  up to 100 stems per hectare. The effects would be minimised by offering  higher allowances, to provide greater feed selection for the stock.  },
	issn = {1176-5283},
	author = {Duckworth JA and Barrell GK}
}
@conference {40282,
	title = {Oestrous behaviour and luteal function in anoestrous red deer hinds treated with a GnRH analogue or oestradiol},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {51},
	year = {1991},
	month = {Jan},
	pages = {55-62},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Five-year old Coopworth pregnant twin bearing ewes were  allocated to four periods of treatment which commenced either -4, 0, 6  or 12 weeks from lambing periods 1 to 4, respectively. Within each  period, pregnant ewes were further allocated to one of two groups (n+6)  one receiving 4000 Ostertagia(Teladorsagia)  circumcincta larvae per day for 30 days (MCI) or no infection  (NIC). All ewes were housed indoors and offered a pelleted diet.  Faecal egg counts, ewe liveweight, food intake, milk production and  serum pepsinogen were determined weekly. Wool growth, fibre diameter  and tensile strength were determined on wool grown within each  experimental period. Abomasal damage, as judged by serum pepsinogen,  occurred during all periods of infection. The magnitude of production  losses varied with time of challenge. Parasitism reduced milk  production by 10-59\% (p<0.01) and wool staple strength by 29-44\%  (p<0.01) with greatest effects on wool staple strength being recorded  during period 1. During lactation food intake (p<0.01) was reduced by  30\% in period 1 by parasitic infection but little effect was seen prior  to parturition. These data confirm that significant production losses do  occur in breeding ewes. The effects on ewe production of any larval  challenge will depend on the timing of the challenge will depend on the  timing of the challenge and on the susceptibility of the ewe to  infection at that time.  },
	issn = {1176-5283},
	author = {Duckworth JA and Barrell GK}
}
@conference {40136,
	title = {Effect of melatonin immunisation on liveweight gain of red deer},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {49},
	year = {1989},
	month = {Jan},
	pages = {29-34},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {The primary constraint to extended milking intervals of dairy cattle without loss of solids production is the storage capacity of the udder needed to accommodate the milk produced over the extended period. This constraint may be overcome by the production of more concentrated milk as the volume of production is a major determinant of udder capacity. The production of more concentrated milk is being explored by two approaches. The first exploits the natural variation in milk solids{\textquoteright} concentration present in commercial dairy herds. The herd test records from LIC, NZDB were used to identify 2 groups of 19 high breeding index Jersey cows with either high or low milk solids content, which were subsequently established at Ruakura in June 1988 along with 19 high BI Friesians. Mean fat concentration in November 1988 was 6.61, 5.32, and 4.74 for high and low solids and Friesian groups respectively. Corresponding values for protein content were 4.34, 3.72 and 3.42\%. Effective hours worth of udder capacity in October-November 1988 was 27.4, 24.8 and 22.9 hours for high solids, low solids and Friesian groups respectively. The second approach involves the use of recombinant DNA techniques to modify the expression of the a-lactalbumin gene, a key component in water secretion in milk. Alpha-lactalbumin, one of the major whey proteins and a component of the enzyme lactose synthetase, plays a major role in regulation and synthesis of lactose, which in turn is the major osmole of milk. Antisense RNA and RNA enzymes can be used for highly specific inhibition of gene expression. These gene blocking agents bind to the {\textquoteright}natural{\textquoteright} mRNA and block translation of the message into a protein. An antisense RNA construct with RNA enzyme cleavage activity against the a-lactalbumin gene has been constructed and is currently under evaluation. This construct will be placed downstream to a mammary specific promoter region and inserted into the bovine genome by gene transfer techniques to produce a transgenic animal. These techniques have considerable potential as tools in physiological studies and for producing animals of superior genotypes.},
	issn = {1176-5283},
	author = {Duckworth JA and Barrell GK}
}
@conference {40093,
	title = {Induction of ovulation in anoestrous red deer hinds with a GnRH analogue},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {48},
	year = {1988},
	month = {Jan},
	pages = {71-76},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Mixed-age Coopworth ewes (594) were allocated to 18 groups on the basis of age and live weight. Three groups (n=33) were treated and joined every second month from June 1986 until April 1987. Ewes were treated with controlled internal drug releasers (CIDR) for 14 d and either 0, 400 or 800 iu pregnant mare serum gonadotrophin (PMSG) at CIDR removal. Entire Poll Dorset rams (10\%) were joined at CIDR removal and changed every 6 h during oestrus. Data on interval from CIDR removal to onset of oestrus, duration of oestrus, ovulation rate, pregnancy rate and lambing performance were recorded for all groups. The interval from CIDR removal to the onset of oestrus increased in the non-breeding season and this was modified by PMSG treatment which shorted the interval. The duration of oestrus was shorter in the non- breeding season in ewes with no PMSG and longer in ewes with the higher dose of PMSG. Both dose levels of PMSG prevented the out-of-season reductions in the incidence of oestrus and ovulation. Ovulation rate increased with dose of PMSG and all treatments showed a seasonal change. A decline in conception rate was a major problem even in PMSG treated ewes during the non-breeding season.},
	issn = {1176-5283},
	author = {Duckworth JA and Barrell GK}
}
