@conference {41407,
	title = {Strategies to encourage adoption: a case study of New Zealand farmers and their possum control practices},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {63},
	year = {2003},
	month = {Jan},
	pages = {66-68},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Queenstown},
	abstract = {Ecological scientists and policy agencies have identified possums (Trichosurus vulpecula) as a pest of both biodiversity and agricultural production. However it has been unclear whether farmers would take action to control possums for biodiversity reasons if their potential threat to agriculture was reduced. In 2002 a survey was made of New Zealand livestock farmers, of whom 85\% had control measures in place. From the data, a regression model was developed for predicting farmers{\textquoteright} intentions to control possum numbers. The model had a squared multiple regression co-efficient of 62\%. The individual regression coefficients all had F probabilities <0.001. It is apparent that possum control on farms is mainly undertaken to reduce the threat of bovine tuberculosis (Tb) in cattle. Farmers are also more likely to take steps to control possum numbers when they consider it will reduce pasture damage, contribute to an overall reduction in farm pests, and reduce damage to their fruit trees and gardens. Control is discouraged by risks of poisoning farm dogs and high costs. Policy agencies will need to work with scientists to provide the information landowners need to encourage their greater commitment to possum control even when the Tb threat has been reduced. },
	issn = {1176-5283},
	author = {Parminter TG and Wilson JA}
}
@conference {41344,
	title = {Genetic engineering and the public: Attitudes, beliefs, ethics and cows},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {62},
	year = {2002},
	month = {Jan},
	pages = {179-182},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Palmerston North},
	abstract = {A postal survey (n = 1682, margin of error 3\%) used a hypothetical milk product with medical benefits produced by genetically engineered (GE) cows as a stimulus to examine New Zealanders{\textquoteleft} support and attitudes towards GE for food and medicine. Beliefs about proposed benefits of GE, ethical issues associated with GE, and ethical perceptions about the status and treatment of cows were canvassed. Ten times as many respondents totally opposed GE food as totally supported it. Medical applications (15.6\%) received significantly more total support than GE food production (3.4\%). A majority of respondents were prepared to support GE under some circumstances (medicine 61.8\%, food 51.7\%) - implying their need for case-by-case analysis. Respondents disagreed GE will: cure the world{\textquoteleft}s major diseases, solve the world{\textquoteleft}s food problems, improve the quality of animal lives, be environmentally benign, or that the spread of GE organisms can be controlled. GE did not fit with respondents{\textquoteright} cultural and spiritual beliefs or basic principles. Although agreeing the instrumental use of cows by humans was acceptable, respondents strongly disagreed genetic modification of cows for human benefit was acceptable. Consistent significant differences were found between males and females on all the above issues. },
	issn = {1176-5283},
	author = {Small BH and Peddersen JA and Wilson JA and Parminter TG}
}
@conference {41381,
	title = {Incidence and perceptions of cryptorchid lambs in 2000},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {62},
	year = {2002},
	month = {Jan},
	pages = {334-336},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Palmerston North},
	abstract = {<p>A telephone survey of 400 randomly selected sheep farmers was undertaken to determine the incidence of ram, cryptorchid, and wether lambs in the New Zealand lamb flock in 2000. Respondents were asked why they choose to produce rams, cryptorchids or wethers and how willing they would be to change. The percentage (+/-5\%) of male lambs left entire and made cryptorchids was similar at 39\% and 41\% respectively with the remaining 20\% wethers. The primary reasons why farmers produced cryptorchids was to achieve good lamb growth rates and lean carcasses without having fertile male lambs. Published research reports support the perception of leanness relative to wether lambs but indicate that carcass weights are similar to those of ram and wether lambs and that some cryptorchids may be fertile. Secondary reasons given for producing cryptorchids were that they were cleaner and easier managed than ram lambs. Although the production of cryptorchids has declined in recent years, 71\% of the farmers who currently produce them have a preference for this method and indicated unwillingness to change from this practice.</p>},
	issn = {1176-5283},
	author = {Tarbotton IS and Bray AR and Wilson JA}
}
@conference {41111,
	title = {Angus selection-herd reproductive data: A genetic model for dairy cattle?},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {59},
	year = {1999},
	month = {Jan},
	pages = {169-172},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {A selection experiment with Angus cattle, established in 1984/85, has achieved a difference in age at puberty in heifers of 70 + 6 days (17\%) between an {\textquoteleft}Age Plus{\textquoteleft} (i.e. high age) selection line and an {\textquoteleft}Age Minus{\textquoteleft} line. Currently three heifer calf crops (born in 1993-95) are being retained until 5.5 years of age, so that pregnancy rates in 5 mating seasons (and calving data in 4 seasons) on unculled females can be recorded. Genetic correlations between pubertal traits (from either sex) and heifer or cow reproductive traits have been calculated. Similar estimates were also derived from a pilot beef-cattle trial in 1980-85 using paternal half-sib data (230 sire groups), but no selection. The objective of this paper is to evaluate the merits of selecting on pubertal traits to improve reproduction, and to assess the possibilities of this type of selection in dairy cows. Correlated responses in the {\textquoteleft}Age Minus{\textquoteleft} herd, relative to {\textquoteleft}Age Plus{\textquoteleft}, include earlier pubertal development in half-brothers (+1.6 cm (5.2\%) in scrotal circumference (SC) at 8, 10 and 12 months of age, P<0.001), an earlier mean calving date in cows by 3 days following an unchanged start-of-mating date, a 3-day reduced postpartum anoestrous interval (PPAI, adjusted for the earlier calving date), and a higher mean pregnancy rate (+4.7\%, based on 1083 matings) in cows 2 years of age or more (P<0.05). All the genetic correlations between age at puberty in heifers and cow reproductive traits in our two studies so far have favourable signs (e.g. negative between age at puberty and pregnancy rate, or positive between age at puberty and PPAI), so that selecting heifers for earlier pubertal age would be consistent with increasing cow reproduction. Because selecting heifers for puberty is not very practical, selecting bulls could be more realistic. All the genetic correlation estimates between SC and cow reproductive traits in our two studies so far also have favourable signs. Additionally, genetic correlations between SC in bulls and age at puberty in heifers are negative (-0.21 {\textpm} 0.09 and -0.19 {\textpm} 0.20, respectively in the two trials cited above), so that bull selection for higher SC would reduce age at puberty in heifers and improve cow reproduction. Thus direct selection for precocious puberty in our Angus herd (predominantly by bull selection) has led to more fertile beef cows. It is suggested that the genetic correlations observed could be an initial model for dairy cattle, showing how selection-index traits on dairy animals at puberty could be used to correct for the inferior reproductive genes of some dairy cows. },
	issn = {1176-5283},
	author = {Morris CA and Verkerk GA and Wilson JA}
}
@conference {40956,
	title = {Muscle distribution in lamb progeny from several breeds.},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {57},
	year = {1997},
	month = {Jan},
	pages = {267-270},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Leg and shoulder composition (fat, muscle and bone) and some linear fat and muscle distribution measurements were taken on 458 lambs produced by 39 strains and breeds of ram born in 1992, 1993 and 1994. Lambs were either Romney or Romney-cross. Texel-cross lambs had the highest proportion of muscle in the leg and shoulder cuts with the Poll Dorset-cross lambs having a similar amount. Southdowns, American Suffolks and Romney strains had least muscle, and apart from the American Suffolk, also had most fat. The fat selected Southdown-cross had the highest \% carcass fat. There was no significant difference between any of the sire groups in the proportion of the major defatted leg primal cuts. All genotypes had a similar leg muscle cut distribution, breed differences being only in the relative proportions of muscle to fat and bone. The Texel-cross had the highest weight (at the same carcass weight) of psoas muscle and the ultrasonically selected Poll Dorset progeny had the highest proportion of measured lean as longissimus muscle. },
	issn = {1176-5283},
	author = {Kirton AH and Duganzich DM and Mercer GJK and Clarke JN and Dobbie JL and Wilson JA}
}
@conference {40873,
	title = {Progress with selection to change age at puberty and reproductive rate in Angus cattle.},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {57},
	year = {1997},
	month = {Jan},
	pages = {9-11},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Trying to improve beef cow pregnancy rate by genetic selection within a breed is generally considered to be slow and difficult. We have investigated a promising option which involves selecting to change age at puberty in heifers and then exploiting the genetic correlation with lifetime pregnancy rate. Angus herds were established from a common foundation population in the early 1980s, and were then selected from 1984 for reduced age at puberty (AGE-) or increased age at puberty (AGE+), with a control herd for comparison. Relative to the AGE+ herd, heifers born in the AGE- herd in 1993 and 1994 were 83 days (=20\%) younger at puberty (P<0.001), and their half brothers had 2.0 cm (=6.6\%) greater scrotal circumference (P<0.001). Corresponding live weights in the AGE- herd were 17\% less at puberty (P<0.001), not significantly different between herds at birth, weaning or 8 months of age, and 3.5\% higher as yearlings (P<0.01) than in the AGE+ herd. Conception rates for the 1992-95 matings were 91.2 and 71.2\% (P<0.001) for AGE- and AGE+ yearling heifers, but not yet significant at 89.6 and 85.0\% respectively for older cows. Restricted maximum likelihood estimates of heritability for age at puberty and scrotal circumference (mean of 3 measurements) were 0.27{\textpm}0.04 and 0.48{\textpm}0.05, with a genetic correlation of -0.29{\textpm}0.10. Phenotypic standard deviations for age at puberty in the AGE- and AGE+ herds were 51 days for each herd. However, within-herd heritabilities for age at puberty were 0.32{\textpm}0.11 and 0.13{\textpm}0.14 for the AGE- and AGE+ herds, respectively, which suggests to us that different modes of inheritance should be investigated in each herd. },
	issn = {1176-5283},
	author = {Morris CA and Wilson JA}
}
@conference {40683,
	title = {Evaluation of muscling using Texel and Oxford cross Romney and Hight Romney lambs},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {55},
	year = {1995},
	month = {Jan},
	pages = {108-110},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Selection for out-of-season breeding ability could be enhanced if an  early indication of the trait was available. The onset of hogget oestrus has  been proposed as such a trait and has been examined for 362 ewe progeny  coming from early and late-lambing selection lines over 3 years.   In each year the early lambing (BV-) hoggets had an earlier (P<0.05) mean  date of onset of oestrus than the hoggets from the late-lambing (BV+) line.   In 1992 and 1993 this effect was confounded by the season of birth such that  nearly all the BV- animals were autumn born (AB) and the BV+ animals  born in the spring (SB). In 1993 animals from both lines were produced in  both seasons. Their mean day of first oestrus in 1994 (expressed as day of  year },
	issn = {1176-5283},
	author = {Kirton AH and Mercer GJK and Clarke JN and Dobbie JL and Duganzich DM and Wilson JA}
}
@conference {39923,
	title = {The effects of lamb breed, slaughter age and sex on carcass fat depth and export grade},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {44},
	year = {1984},
	month = {Jan},
	pages = {227-230},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {A least squares analysis of the weight of 15 individual export cuts from 808 carcasses of 20-month old steers identified significant effects of carcass weight, carcass fat measurements, carcass grade and sire breed on the weight of export cuts. Increasing carcass weight had a positive effect on cut weight but increasing carcass fatness had a variable effect on weight of cut. The weight of cut marketed with negligible subcutaneous fat (cube roll) decreased in weight by 7\% as carcass fat depth increase from 4 to 12 mm. In contrast a cut which included subcutaneous fat increased in weight by 15\% over the same fatness range. The data show that the most equitable pricing system (schedule) would take account of weight of individual cuts.},
	issn = {1176-5283},
	author = {Geenty KG and Young SR and Clarke JN and Wilson JA}
}
@conference {39911,
	title = {Terminal sire comparisons of the Charolais and Murray Grey breeds for calving difficulty, calf survival and growth},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {44},
	year = {1984},
	month = {Jan},
	pages = {177-180},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {An enzyme-linked immunosorbent assay (ELISA) system has been developed for the detection of an endophytic fungus of Lolium perenne. The technique has been used to demonstrate quantitative differences in the spatial and tissue distribution of the endophyte in vegetative and reproductive tillers of infected plants. The influence of this on pasture toxicity is discussed. The nature of the endophyte antigen is described and the relationship between the antigen and toxicity discussed.},
	issn = {1176-5283},
	author = {Morris CA and Baker RL and Wilson JA}
}
@conference {39790,
	title = {Evaluation of dam breeds and crosses for export lamb production},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {42},
	year = {1982},
	month = {Jan},
	pages = {133-136},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {The effects of castrating and surgically dehorning male Drysdale and Tukidale lambs at birth or docking on subsequent horn growth were investigated in 3 lamb crops at Whatawhata Hill Country Research Station. Castration was more effective than dehorning in reducing subsequent horn growth. A combination of castration at birth and dehorning at docking was the most effective way to treat lambs to reduce horn growth. Excision of germative tissue around the base of the horn following dehorning increased the effectiveness of dehorning. Attainment of meat inspection standards for horned breeds is more dependent on the "trimmers" on the slaughter chain than the time of dehorning.},
	issn = {1176-5283},
	author = {Clarke JN and Atkins KD and Geenty KG and Johnson DL and Hickey SM and Wilson JA}
}
@conference {39413,
	title = {Comparison of pen and paddock systems for the pedigree mating of sheep},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {34},
	year = {1974},
	month = {Jan},
	pages = {23-27},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	issn = {1176-5283},
	author = {Clarke JN and Geenty KG and Bennett RG and Christensen GN and Wilson JA}
}
