@conference {41025,
	title = {The effects of a cation-anion balanced diet on calcium and phosphorus metabolism in growing lambs},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {58},
	year = {1998},
	month = {Jan},
	pages = {192-194},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {During the past decade, there has been renewed interest and research in the role of the dietary cation-anion balance (DCAB) in controlling Ca and P homeostasis. Two diets differing in DCAB (either high DCAB, 250 meq/kg DM, or low DCAB, -100 meq/kg DM) were fed to 10 Romney lambs. Feeding low DCAB decreased urine pH by 2.0 pH units; from 8.2 (SE=0.45) to 6.2 (SE=0.50), indicative of the anticipated changes in the ionic balance associated with alterations in the dietary CAB. Plasma concentrations of Ca and P, and whole-body Ca and P balance (intake-excretion) were similar for both groups of sheep. Reducing the dietary CAB caused a 7-fold increase in the urinary excretion of Ca (low DCAB 0.75 g/day vs high DCAB 0.11 g/day; P=0.001).The apparent absorption of Ca in the low DCAB and high DCAB groups were 1.6 and 1.3 g/day, respectively, although there was no significant difference between the two groups. These data indicate that lowering the DCAB increases urinary excretion of Ca of growing lambs without affecting Ca balance due to an alteration in the movement of Ca to and from bone. Similar changes in Ca absorption and utilisation have been observed in dairy cows, suggesting that the growing lamb is a suitable model for future studies in the regulation of Ca homeostasis in dairy cattle. },
	issn = {1176-5283},
	author = {Wilson KL and Min S and Revell DK and Lee J and MacKenzie DDS and Cottam YH and Davis SR}
}
@conference {41034,
	title = {Monitoring some muscoid fly populations on Massey University sheep farms in the Manawatu},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {58},
	year = {1998},
	month = {Jan},
	pages = {220-223},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Over three summers (1993-94, 1996 and 1996-97), four fly-traps were placed at each of two locations on Massey University farms. Caught flies comprised eight species, of which four are commonly involved in flystrike. Australian sheep blowfly (Lucilia cuprina) numbers caught varied dramatically between years. At the season peak, numbers in 1996 and 1996-97 were three and one and a half times higher, respectively, than in the first year. Average weekly fly catch increased rapidly over a 2-3 week period from near zero to a peak (in years 1996 and 1996-97) of about 30 flies for L. cuprina and from near zero to a peak (in 1996-97) of about 75 flies for Chrysomya rufifacies in February/early March. Peaks presumably reflected emergence of adult flies from the previous year{\textquoteright}s pupae that overwintered in the soil. Five of the eight species showed a second peak about four weeks after the first. The second peak most likely reflects emergence of a second generation. Minimum temperature explained a significant proportion of variation (up to 48\%) in fly numbers. Rainfall and wind run were less important. Further work is required to provide robust indicators of potential rises in fly numbers. },
	issn = {1176-5283},
	author = {Cottam YH and Blair HT and Potter MA}
}
@conference {40937,
	title = {Control of Reproductive Success in Rabbits Using Bromocriptine.},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {57},
	year = {1997},
	month = {Jan},
	pages = {222-224},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Feral rabbits impose a substantial environmental and economic cost in this country, causing pasture devastation over large areas of land, accelerating erosion and decreasing vegetation cover. Existing or potential methods of control have a high ethical cost, and there is a need to identify new methods of control. Manipulation of lactation, to enhance mortality and inhibit growth and development of the young, is a possible alternative strategy. Prolactin (PRL) is known to be important for establishment and maintenance of lactation in rabbits, and PRL secretion may be inhibited by administration of ergot alkaloids such as bromocriptine (CB154). These substances are orally active and so could potentially be used in baits. In order to determine whether CB154 could be used in baits, it is first necessary to establish the lowest effective dose. The objective of this study was to examine the relationships between dose of CB154 (initially administered systemically) and the growth and survival of kits. Sixteen pregnant New Zealand White does were divided into four treatment groups receiving different doses (mg/kg live weight/d) of CB154 ("low"(L), 0.2; "medium"(M), 0.4; "high"(H), 0.8; and control (C), 0). From day 3 of lactation, does were injected once daily with CB154 or excipient. Treatment continued until day 14 or until the death of all the kits, whichever came first. There were significant treatment effects on the proportion of kit deaths on all measurement days. By day 17, kit mortalities were: C, 20\%; L 42\%; M, 64\%; H, 71\%;) (P<0.05). The weight gain of the surviving kits from day 3 to 8 did not differ significantly between treatment groups, but kit weight gain day from days 8 to 13 showed a significant treatment effect (P<0.01) (control, 83.7{\textpm}11.4g; low, 18.7{\textpm}11.4g; medium, 33.5{\textpm}17.2g; high -0.8{\textpm}14.9g). Results are discussed in relation to the possible use of bromocriptine as a bait to control reproductive success, and to the fact that these rabbits were much less sensitive to bromocriptine than previously published studies would suggest. },
	issn = {1176-5283},
	author = {Cottam YH and Peterson SW and McCutcheon SN}
}
@conference {40932,
	title = {Metabolic changes in the mammary gland of sheep prior to, and at, parturition.},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {57},
	year = {1997},
	month = {Jan},
	pages = {209-211},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Four sheep fitted with an indwelling catheter in the femoral artery and a transit time ultrasonic flow probe around the left pudendal artery (supplying the mammary gland) were used to quantitate changes in mammary blood flow (MBF) in late pregnancy and lactation, and to determine the extraction of glucose and oxygen by the mammary gland. Mammary vein blood samples were collected by venipuncture. Considerable variation existed in the pattern of change in MBF between individual sheep. In two animals, MBF through the pudic artery fitted with the flow probe doubled to 600 mL/min on the day of lambing (DL), while in the other two sheep, MBF varied little in response to lambing. Possible explanations for this difference between individuals are discussed. Glucose extraction trebled on DL from 6.0 to 18.7\% (P<0.01) and remained high during lactation in relation to milk output. Oxygen extraction by the mammary gland peaked during the last week of pregnancy (at 45.7\%) and during lactation it was related linearly to milk output. },
	issn = {1176-5283},
	author = {Revell DK and Harris PM and Cottam YH and Reynolds GW and Lee J}
}
@conference {40881,
	title = {The use of fly attractants to encourage flystrike for sheep selection purposes.},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {57},
	year = {1997},
	month = {Jan},
	pages = {37-40},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {The incidence of flystrike in New Zealand flocks is about 3\% in most years. This low level of prevalence makes it difficult to discriminate between potential flock replacements based on naturally occurring flystrike. Selection decisions could be improved if either the rate of flystrike could be raised artificially or an easily measured trait that has a higher level of occurrence could be found. The second approach is used in Australia where fleece-rot has both a higher incidence rate than flystrike and is highly genetically correlated to susceptibility to flystrike. However, the incidence of fleece-rot in New Zealand dual-purpose sheep is not sufficiently high to allow its use as an indirect indicator. In a effort to find a means of artificially increasing the incidence of flystrike, groups of hoggets were brought indoors and exposed to the Australian green fly Lucilia cuprina. In total, 5 trials (10 animals/treatment) were run to compare: the susceptibility of Romney vs Perendale sheep, using wetting, dung or homogenised liver as attractants. Wetting was applied along the back from a watering can while the other attractants were applied to a patch on the shoulder, mid-back and rump. About 2000 gravid flies were released into a fly-proof room along with the penned sheep. The main results of these trials were: a) It was very difficult to get an established maggot population on clean wet sheep; few eggs were laid and no cases of established strike occurred; b) Dung acted as a moderately successful attractant; maggots were hatched on the sheep but none developed to the skin penetrating stage; c) Liver acted as a very successful attractant and maggots developed on all treated sheep. No between-breed differences occurred with wetting, dung or liver attractants. Further studies are required to refine the use of attractants. In particular, an attractant that is less powerful than homogenised liver but more potent than wetting or dung is required before moving onto large-scale field trials. },
	issn = {1176-5283},
	author = {Blackwell GL and Potter MA and Cottam YH and Blair HT}
}
@conference {40576,
	title = {Mammary involution in ewes: Changes in milk plasminogen and plasmin},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {54},
	year = {1994},
	month = {Jan},
	pages = {107-110},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Multiparous Border Leicester x Romney ewes were weaned early (day 35  
of lactation), milked to empty the mammary gland and again milked 18 h later  
(day 0 of experiment) to establish baseline milk yields and concentrations in  
milk of the proteolytic enzyme plasmin and its zymogen plasminogen.  They  
were then divided into 3 groups to be milked 3 (n=5), 8 (n=6) or 15 (n=5) days  
after the day 0 milking to determine changes in concentrations and yields of  
plasmin and plasminogen in mammary gland secretions during involution.   
Yields (mean{\textpm}SE) on days 0 (groups 1 + 2 + 3), 3 (group 1), 8 (group 2) and 15  
(group 3) were: secretion (g), 785{\textpm}31.2 v. 598{\textpm}94.8 v. 478{\textpm}86.8 v. 51{\textpm}66.6;  
plasminogen (mg), 7.8{\textpm}2.2 v. 78.7{\textpm}11.1 v. 22.4{\textpm}4.6 v. 3.9{\textpm}2.1; and plasmin  
(ug), 11.5{\textpm}2.38 v. 148.5{\textpm}8.00 v. 51.6{\textpm}7.92 v. 4.9{\textpm}2.32.  Corresponding  
concentrations in the secretions were (ug/ml): plasminogen, 0.01{\textpm}0.002 v.  
0.15{\textpm}0.027 v. 0.046{\textpm}0.005 v. 0.061{\textpm}0.007; and plasmin, 0.015{\textpm}0.006 v.  
0.275{\textpm}0.027 v. 0.118{\textpm}0.011 v. 0.083{\textpm}0.009.  There was a linear decline in the  
volume of secretions from day 0 to day 15.  In contrast there was a transient  
increase (15 fold) in plasminogen and plasmin yields by 3 days after milking.   
These data suggest that any role of plasmin in mammary gland involution is  
likely to be limited to the first week after early weaning. },
	issn = {1176-5283},
	author = {MacKenzie DDS and Cottam YH and Knutson RJ and McCutcheon SN}
}
