@conference {69508,
	title = {Wool characteristics in the Meat and wool New Zealand Central Progeny Test flocks},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {70},
	year = {2010},
	month = {Jun},
	pages = {217-221},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Palmerston North},
	abstract = {The Meat and Wool New Zealand Central Progeny Test programme (CPT) was established to demonstrate the relative breeding merit of leading sires in the New Zealand sheep industry. Here we describe the wool grown over the summer by the 2007 born one-year-old ewes within the CPT. Within fleeces, staple strength varied between farms as shown by the mean difference of 23 N/ktex in offspring of the link sire. Staple strength correlated positively with midside fibre diameter (r = 0.26), medullation (r = 0.23) and negatively with fibre curvature (r = -0.61). Staple strength was similar on anterior (74 {\textpm} 24 N/ktex) and midside (75 {\textpm} 24 N/ktex) body-sites, but was weaker on the hindleg (64 {\textpm} 21 N/ktex; P <0.001). Overall mean staple strength was 72 {\textpm} 20 N/ktex, while individual fleeces ranged from 19 to 121 N/ktex. Ten percent of fleeces measured below 45 N/ktex leaving them prone to excessive fibre breakage during processing. Some fleeces varied up to 40 N/ktex across body-sites. Even within one flock, offspring of individual sires differed by a mean of 29 N/ktex, suggesting a consistent weakness of wool in the progeny of some highly ranked sires which will negatively affect processing and end-product performance.},
	issn = {1176-5283},
	author = {Craven AJ and Ashby MG and Scobie DR}
}
@conference {60950,
	title = {Variation of wool between and across the fleeces of composite-breed strong wool sheep in New Zealand},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {69},
	year = {2009},
	month = {Jun},
	pages = {90-95},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {Many farmers in New Zealand have moved towards using composite-breed sheep flocks to increase the meat production and fecundity of their stock. We aimed to determine whether flocks with a wider genetic base had greater between and within-fleece variation than single-breed flocks. Wool from seventeen body sites of sheep from five flocks of diverse genetic background (Romney, Coopworth, and crosses with Texel, Finnish Landrace and East Friesian breed lines) were compared. Both mean fibre diameter and mean fibre curvature differed between flocks (P <0.001), and across the body (P <0.01). While fibre diameter was more consistent, fibre curvature was more variable across the finer fleeces of flocks with some Finnish Landrace influence. Wool was shorter in Texel crosses, resulting in more consistent length across body sites. Our data suggests that composite-breed sheep exhibit increased within-fleece variation of some wool traits and decreased variation of others. Of most significance was that the extent of wool variation across body sites varied considerably between sheep, regardless of their genotype. In general, there was little association between wool traits with respect to this across-fleece uniformity. Fleece uniformity can be assessed by sampling across the anterior-posterior axis. Selection of stock with more uniform fleeces for specific traits may aid the production of wool better specified to satisfy differentiated niche markets. },
	issn = {1176-5283},
	author = {Craven AJ and Ashby MG and Wildermoth JE and Cox NR and Scobie DR and Nixon AJ}
}
@conference {41784,
	title = {Gene expression profiling of wool follicle growth cycles by cDNA microarray},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {68},
	year = {2008},
	month = {Jan},
	pages = {39-42},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Brisbane, Australia},
	abstract = {Wool growth in Wiltshire sheep was synchronised by daylength manipulation to allow identification of genes that are regulated during transitions in the wool follicle cycle. Pair-wise comparisons between growing and resting phases were conducted using both direct and indirect cDNA microarray analysis. The two approaches were well correlated at three different levels: overall similar patterns of gene expression, detection of changes in keratin gene expression, and reduced differential expression between closer cycle stages. Using more slides, the indirect approach identified more expressed sequence tags (ESTs) (indirect 1132, direct 444), and had higher coverage of wool keratins (indirect 78\%, direct 42\%). This study demonstrates the usefulness of cDNA microarray for expression profiling in whole skin. Further characterisation of genes identified by this work, particularly the smaller sets of ESTs derived from comparisons at early stages of follicle regression and regrowth, would improve our understanding and provide leads for alternative wool harvesting technology or enhancing wool growth. },
	issn = {1176-5283},
	author = {Yu Z-D and Gordon SW and Pearson AJ and Henderson HV and Craven AJ and Nixon AJ}
}
@conference {41788,
	title = {Wool follicle characteristics in sheep with differing ventral wool length phenotypes},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {68},
	year = {2008},
	month = {Jan},
	pages = {49-52},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Brisbane, Australia},
	abstract = {Recent interest in sheep requiring less on-farm fleece management has lead to the development of sheep with long wool covering the trunk, but only short wool on the belly and breech. We have characterised developmental and structural features of the skin, including follicle density, primary to secondary follicle ratio and follicle activity state at various body sites of bare- and woolly-bellied ewes, and their foetuses. At 70 days of gestation, foetuses of bare-bellied ewes had developed fewer follicles than woolly-bellied sheep (1.7 {\textpm} 0.27 versus 2.8 {\textpm} 0.21 follicles per mm2; P<0.01). In adults, similar densities and ratios of primary to secondary follicles occurred in bare- and woolly-bellied ewes in each body site studied including dorsal, midside, anterior and posterior fleece positions, as well as the belly, breech and face. However, the proportion of inactive follicles in late autumn was greater in bare-belly adult ewes, not only on the belly (15.5 {\textpm} 1.9\% versus 4.9 {\textpm} 2.9\%; P<0.05), but also across the fleece which exhibited anterior-posterior and dorsal-ventral gradients in follicle activity. The short wool phenotype was thus associated with altered follicle cycles, but no differences in adult follicle densities. However, wool production might be compromised, as follicle activity varied across the whole fleece of bare-belly sheep. },
	issn = {1176-5283},
	author = {Craven AJ and Scobie DR and Ashby MG and Nixon AJ}
}
@conference {42003,
	title = {Culture of ovine keratinocytes : An experimental model for wool growth},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {67},
	year = {2007},
	month = {Jan},
	pages = {326-331},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Wanaka},
	abstract = {Wool fibres are formed from the germinative epithelium, a population of keratinocytes at the base of wool follicles. In order to test the function of candidatewool growth genes and pharmaceuticals, we have developed methods to isolate and maintain these cells inculture. Pure, clonal lines of ovine keratinocytes were isolated from both vibrissae and wool follicles. Vibrissa-derived cells proliferated more extensively before senescing, but cells from both follicle types possessed ample proliferative potential for further experimentation. Standard assays have been established to quantify keratinocyte proliferation and apoptosis in culture. Differentiation of keratinocytes could be induced by maintaining them at high density for a week. Keratinocytes expressed differentiation markers for epidermis and inner root sheath. Expression of a chosen gene could be up-regulated by transfection with a liposome-borne plasmid. A transfected plasmid encoding a fluorescent reporter protein was expressed in 68-100\% of cells. Similarly, expression of a gene of interest could be suppressed by RNA interference. The experimental tractability of these keratinocytes suggests that they will be a valuable model for investigating the cell biology and molecular genetics of wool growth. The methods described form a unique experimental system to identify leads for new technologies that improve wool production.},
	issn = {1176-5283},
	author = {Rufaut NW and Goldthorpe NT and Craven AJ and Wallace OAM and Wildermoth JE and Pedersen G and Nixon AJ}
}
@conference {42006,
	title = {Expression of the developmental regulators Msx1 and Msx2 in sheep skin varies with body region and wool growth pattern},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {67},
	year = {2007},
	month = {Jan},
	pages = {345-350},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Wanaka},
	abstract = {The variability of fibre characteristics affects the processing performance of wool and therefore the value of the wool clip. These variations originate during development in utero, and manifest as patterns of fibre growth that differ between body regions. Two transcription factors, Msx1 and Msx2, have previously been linked to regional specification within the skin and alsoact as regulators of differentiation within the hair follicle matrix. In this study, we describe the expression patterns of Msx1and Msx2in multiple body sites of foetuses and adult crossbreed ewes. In foetal skin, the expression of both Msx1and Msx2was greatest in the regions of lower eventual follicle density. In adults, both anterio-posterior and dorso-ventral gradients were observed in Msx1expression across the fleece bearing skin. Higher concentrations of Msx1and Msx2transcripts were present in adultsthan foetuses, possibly reflecting  additional roles in regulating the differentiation and growth of the wool fibre shaft. These results are consistent with the involvement of Msx1 and Msx2 in the development of skin regions, wool follicle growth, and anterio-posterior and dorso-ventral gradients of wool characteristics in sheep},
	issn = {1176-5283},
	author = {Craven AJ and Rufaut NW and Scobie DR and Nixon AJ}
}
@conference {42005,
	title = {Variation of wool characteristics across the body of New Zealand Wiltshire sheep},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {67},
	year = {2007},
	month = {Jan},
	pages = {339-344},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Wanaka},
	abstract = {Variations in wool quality within a sheep arise from inherent differences between sites across the body and between fibres within a site, as well as variationsalong individual fibres that result from nutritional, reproductive and seasonal influences. The Wiltshire sheep is a shedding breed in which there is renewed interest due to the relative values of meat and wool, and the costs of wool production. Staple length, fibre diameter, fibre diameter standard deviation, and medullation were measured on wool grown at seventeen sites across the body of two-tooth Wiltshire rams undergoing a photoperiod-induced wool growth cycle. Staple length was longest on the shoulder (41 {\textpm} 2.5 mm) and shortest on the belly (14 {\textpm} 1.2 mm). There was an inverse correlation between staple length and fibre diameter with the finest fibres on the shoulder and coarsest on the hip (R{\texttwosuperior}=-0.7, P<0.001). This gradient of increasing fibre diameter was associated with increased variation within-staples (R{\texttwosuperior}=-0.8, P<0.001). Fibre medullation increased from the shoulder to the hip. Short coarse fibres on the front and back legs, along with facial hairs highlight differences in major regional skin domains that are established in utero. Although midside samples were representative for each fleece they did not portray the anterior/posterior and dorsal/ventral gradients observed in all characteristics studied. Understanding the within-fleece variation in wool characteristics is a requirement for producing sheep with more desirable fleece distribution patterns.},
	issn = {1176-5283},
	author = {Craven AJ and Ashby MG and Scobie DR and Nixon AJ}
}
@conference {41567,
	title = {Relation between skin structure and wool yellowing in Merino and Romney sheep},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {65},
	year = {2005},
	month = {Jan},
	pages = {197-202},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {Five adult Merino and five adult Romney ewes were skin sampled on the back, midside and belly regions of the body following a study measuring the relationship between rate of sweat secretion and wool yellowing under various controlled environmental conditions. Densities of primary follicles, secondary follicles, sweat (sudoriferous) glands and sebaceous glands, as well as dimensions of the sweat and the sebaceous glands were measured. The density of secondary follicles was negatively related to wool yellowing and there was a weaker positive relationship between the density of primary follicles and wool yellowing. Underlying these relationships were associations of measurements suggesting sebaceous gland output restricted wool yellowing while sweat gland output encouraged wool yellowing. In addition, large sweat glands were related to increased sweat secretion rate. The results of this study suggest there may be two potential avenues to minimise fleece discolouration while the wool is growing on the sheep; either increasing sebum production or reducing sweat production.
KEYWORDS: Romney; Merino; wool yellowing; wool follicles; sweat glands; sweat; sebaceous glands. },
	issn = {1176-5283},
	author = {Sumner RMW and Craven AJ}
}
@conference {41522,
	title = {Relation between sweating and wool yellowing in Merino and Romney sheep},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {64},
	year = {2004},
	month = {Jan},
	pages = {286-292},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Hamilton},
	abstract = {Five adult Merino and five adult Romney ewes with 7 months growth of fleece were subjected to nine different environmental challenges in a climate controlled room on consecutive days where the temperature humidity index (THI) was varied from 74.2 to 91.3 for up to 7 h at each exposure. Secretions were collected from glands in the skin on the back, midside and belly regions of each sheep. The sheep were shorn 5 months later. There was a significantly curvilinear increase in total skin gland output and the rate of secretion of titratable alkalinity and potassium ions with increasing THI. Romney sheep had a higher secretion rate than Merino sheep with no significant site effect. The rate of secretion of titratable alkalinity and potassium ions by the skin glands were both strongly related to tristimulus (Y-Z) of the fleece at shearing (base yellow) (R2 = 0.93, 0.92) and after incubation of the wool sample at 40{\textdegree}C and 100\%RH for 6 d (challenge yellow) (R2 = 0.96, 0.95). These data indicate a particularly strong relationship between the rate of secretion of titratable alkalinity and potassium ions by the skin glands and the later propensity of the fleece to develop a yellow discolouration. },
	issn = {1176-5283},
	author = {Sumner RMW and Ashby MG and Craven AJ}
}
@conference {41188,
	title = {Variation of fibre and follicle characteristics related to wool bulk over the body of Perendale ewes: Implications for measurement of wool bulk},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {60},
	year = {2000},
	month = {Jan},
	pages = {166-170},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Hamilton},
	abstract = {Wool samples were collected prior to shearing in two consecutive years from 8 sites over the body of six adult Perendale ewes differing in wool bulk. A skin sample was collected from the same sites in the second year. Fibre curvature and fibre diameter explained between 67 and 94\% the variation in core bulk at the different sites. No measured characteristics significantly reduced the unexplained variance across all sites. Intercepts for the relationship between fibre curvature and fibre diameter with core bulk at each site were significantly different but less than the confidence limits associated with core bulk measurement. There were no significant differences in the slopes of the same relationships across the eight sites. Use of a pooled relationship to predict bulk from fibre curvature and fibre diameter is a least-cost option to describe the bulk of a fleece. },
	issn = {1176-5283},
	author = {Sumner RMW and Craven AJ}
}
@conference {40660,
	title = {A comparison of protocols for the photoperiodic induction of synchronised wool follicle growth cycles},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {55},
	year = {1995},
	month = {Jan},
	pages = {35-38},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {This study endeavoured to characterise the effects of breed and  calving liveweight (CW) on postpartum (pp) ovarian activity in 16  Friesian (F) and 16 Jersey (J) heifers. Half of the animals within each  breed were differentially fed (High vs Low: H vs L) during the 8 weeks  before calving to achieve CWs (24 h pp) of 404 (FH), 354 (FL), 334 (JH)  and 279 (JL) kg. They were fully fed as one group after calving.  Ovarian ultrasonography showed that the FL group had the longest  postpartum anovulatory interval (PPAI) of 77 days compared to 47 days  among other groups. The second dominant follicle pp emerged 6 days  later in FL heifers. Breed, but not CW, affected follicle patterns in  the first normal oestrous cycle. Underfeeding of Friesian heifers  during late pregnancy extended the PPAI whereas Jerseys were not  affected to the same extent.   },
	issn = {1176-5283},
	author = {Craven AJ and Parry AL and Ashby MG and Pearson AJ}
}
@conference {40583,
	title = {The effect of long-day photoperiod treatments on plasma prolactin and wool follicle activity in New Zealand Wiltshire sheep},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {54},
	year = {1994},
	month = {Jan},
	pages = {135-138},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Exposure of NZ Wiltshire sheep to a long-day photoperiod during late  
winter/spring has previously been shown to alter wool follicle growth patterns.   
The present experiment was undertaken to evaluate the plasma prolactin and  
wool follicle response to treatment with either 1, 2 or 3 months of long days. 
 
Four groups of six, NZ Wiltshire ewes were subjected to long-day photoperiod  
(16L:8D) for 1 month (LD1), 2 months (LD2), 3 months (LD3) or natural  
photoperiod (control), commencing on the 3 August, after which they were  
released from light treatment into natural (indoor) spring daylength.  Weekly  
jugular blood samples were assayed for prolactin (PRL) and skin biopsies were  
histologically assessed for wool follicle activity. 
 
Circulating PRL concentrations were low in all treated and control sheep at the  
start of the experiment (19 {\textpm} 2 ng/ml).  In treated sheep mean PRL  
concentration increased (P<0.05) above control levels (8 {\textpm} 1 ng/ml) within 1  
week after exposure to long days (52 {\textpm} 4, 51 {\textpm} 5 and 55 {\textpm} 2 ng/ml for LD1,  
LD2 and LD3, respectively).  PRL concentrations remained significantly higher  
than controls (P<0.05) for the duration of each treatment reaching maxima of  
148 {\textpm} 27 ng/ml, 180 {\textpm} 43 ng/ml, and 199 {\textpm} 33 ng/ml for LD1, LD2 and LD3  
respectively.  In LD2 and LD3 treatments, PRL concentrations declined to  
control levels by 3 and 2 weeks after treatment had ceased, respectively, but in  
the LD1 treatment PRL remained significantly above (P<0.05) control levels  
until between 2 and 3 months after treatment.  Primary follicle activity (PFA)  
decreased in response to long-day treatment (P<0.01) reaching minima of 47 {\textpm}  
9\%, 36 {\textpm} 6\%, and 33 {\textpm} 11\% in LD1, LD2, LD3 sheep, respectively.  Secondary  
follicle activity (SFA) responses were most marked in the LD2 and LD3  
treatments where they fell below (P<0.05) control levels reaching minima at 2  
months into treatment (66 {\textpm} 15\% and 58 {\textpm} 13\% for LD2 and LD3,  
respectively).  Both PFA and SFA increased to over 90\%, within 1 month after  
release into natural light, in all treatments groups (except PFA for the LD1  
group which took 2 months after release to reach over 90\%). 
 
In support of previously reported trials an increasing level of plasma PRL was  
followed by a decline in follicle activity.  The optimal time frame to achieve an  
effective synchronised follicle regression was between 2 and 3 months of long- 
day treatment.  The long-day treatment system produced a complete follicle  
growth cycle in temporal synchrony and is therefore a potential model for the  
investigation of structural and biochemical processes surrounding transitions  
between active and resting stages of fibre growth. },
	issn = {1176-5283},
	author = {Craven AJ and Parry AL and Wildermoth JE and Pearson AJ}
}
@conference {40519,
	title = {Skin follicle development in South African (SA) and SA x New Zealand Angora goats},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {53},
	year = {1993},
	month = {Jan},
	pages = {327-330},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {The expected value of the solution of the differential equation arising from the allometric hypothesis when the variables are random is found. This solution differs from the deterministic solution, so that predictions using the allometric equation which ignore the stochastic nature of the differential equation are biased. When lease squares estimation is carried out using the deterministic solution, ignoring the stochastic nature of the size variable, the estimate of the constant coefficient of the allometric equation may be severely biased. An example shows mild bias in estimates of the maturity parameter, but large bias in the estimate of the constant coefficient. To obtain unbiased estimates of the parameters in the allometric equation a factor equal to the reciprocal of the square of the size variable must be added to the usual log-log regression used to calculate estimates of the parameters. These results have application to models based on the allometric hypothesis, in particular models which are used in studies of carcass composition and the description of maintenance requirements in animal nutrition. When these models are used for prediction they need to be modified to account for any random variation occurring in the size variable.},
	issn = {1176-5283},
	author = {Parry AL and Death AF and Dick HB and Miller CM and Craven AJ}
}
