@conference {41283,
	title = {Relationship between bulk milk urea nitrogen and reproductive performance of New Zealand dairy herds},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {61},
	year = {2001},
	month = {Jan},
	pages = {192-194},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {New Zealand dairy cows grazing lush spring pasture have relatively high plasma urea nitrogen levels as a consequence of the high soluble crude protein content of this rapidly growing pasture. The elevated plasma urea levels have been implicated as a cause of poor reproductive performance in dairy herds. The aim of this trial was to determine if the bulk milk urea nitrogen levels (BMUNs) collected during the period from calving and through mating were related to the reproductive performance of the herds. Bulk milk samples were collected twice a week from 127 farms during the spring of 1998. The farms were suppliers of the NZ Dairy Group and Kiwi co-operatives. Reproductive performance data was collected from all herds. BMUNs were determined spectrophotomically using Sigma blood urea nitrogen kits. The twice-weekly BMUNs were averaged for each farm and these weekly mean values were centred on the nominated week of mating (W=+1) for the individual farms. There were significant among-farm differences in BMUNs with individual weekly farm values ranging from 5.4 to 26.8 (mg/dl) and the mean (W-3 to W+5) value for farms ranging from 9.6 to 18.8 (mg/dl). There were significant between farm differences in reproductive performance. The percentage of cows submitted for AI in first 3 weeks of mating (\%SR21) ranged from 29.9 to 95.3\%. The percentage of SR21 cows conceiving to that AI (\%Preg1) ranged from 39 to 98.6\% and the percentage of all cows in the herd pregnant by the end of mating (\%Pregall) from 44.9 to 98.4\%. There was some indication of a relationship between reproductive performance and BMUNs in that the change in BMUN level from W-3 to W+5 was significantly correlated within geographic zones with \%SR21 and \%Pregall, correlation coefficients being 0.36 (P=0.013) and 0.37 (P=0.010) respectively. The corresponding correlation for \%Preg1 was only 0.21(P = 0.15). Thus farms for which BMUNs rose over the period W-3 to W+5 had higher reproductive performance than those in the same zone, which showed a fall. However, this accounted for very little of the overall variability. Farms were ranked on their reproductive performance and the average weekly BMUNs for the farms in each quartile calculated. There was no difference in the pattern of BMUNs for the different quartiles of each reproductive parameter. Thus, the measurement of BMUNs would appear to be of little value as an indicator or predictor of reproductive performance. },
	issn = {1176-5283},
	author = {Smith JF and Beaumont S and Hagemann L and McDonald RM and Peterson AJ and Xu ZZ and Duganzich DM}
}
@conference {41284,
	title = {Relationships between, milk production, nutrition and reproduction in benchmark herds},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {61},
	year = {2001},
	month = {Jan},
	pages = {195-198},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {Inter-relationships between nutrition, milk production and reproduction in dairy cows were investigated in dairy herds with previous high reproductive performance. Ten herds were selected as {\textquoteleft}benchmark{\textquoteleft} farms from one area of the Waikato. Pasture and supplement intakes, and milk production were monitored on a herd basis. Bulk milk samples were taken weekly from calving through to the first three weeks of mating and assayed for levels of progesterone, urea nitrogen and b-hydroxybutyrate (BOH). Pre-mating oestrus, mating (AI) and pregnancy data were recorded. All data was expressed in relation to the planned date of mating (PSM) for each farm. Significant between farm differences were detected in all the reproductive parameters but there was no effect of supplement feeding. The mean proportion of cows cycling at PSM was 65.6 {\textpm} 3.3\% (range 50.5 to 81\%).The mean proportion of cows pregnant to AI at PSM + 3 weeks was 51.3 {\textpm} 2.1\% (range 43 to 61.5\%); at PSM + 6 weeks the mean was 74.5 {\textpm} 3.3\% (61 to 89.5\%); at PSM + 9 weeks it was 84.7 {\textpm} 2.2\% (74.9 to 91.6\%) and at PSM + 12 weeks it was 91.3 {\textpm} 1.2\% (85.6 to 95.4\%). Bulk milk progesterone rose linearly from a mean of 0.5 ng/ml at 8 weeks before PSM to 5.0 ng/ml at PSM and to 6.0 ng/ml three weeks later. The difference between farms at PSM ranged from (2.1 to 7.1 ng/ml). While the pattern of increase in bulk milk progesterone tended to mimic the overall pattern of oestrus activity, there was no relationship in the ranking of farms for these parameters at any time. Bulk milk BOH showed no consistent pattern over the period of measurement and levels ranged between farms in any one week from 0.01 to 0.05 mM. Bulk milk urea nitrogen concentration also showed little change on average (7.25 mM) over the pre-mating and mating periods. The significant between-farm differences in these bulk milk parameters did not appear to be related to reproductive performance. Metabolic indicators measured in bulk milk samples appear of little value for predicting reproductive performance at herd level. },
	issn = {1176-5283},
	author = {Smith JF and Verkerk GA and Clark BA and McKay BJ and Duganzich DM}
}
@conference {41125,
	title = {Effect of very low sperm doses on pregnancy rates after AI in sheep.},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {59},
	year = {1999},
	month = {Jan},
	pages = {219-222},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Low sperm numbers and ambient temperature storage are two important factors in the successful AI system for dairy cattle in New Zealand. A critical evaluation of these factors with ram semen is required before the establishment of a similar AI system within the NZ sheep industry is feasible. A trial involving a total of 1262 Romney ewes was conducted in April 1998 to examine the effects of inseminate dose (25, 5, 1 and 0.5 x 106 sperm) of semen held for up to 9 h at 20{\textdegree}C in two diluents (RSD-1 and RSD-8). Ewes, synchronised with 3 types of CIDR devices were laparoscopically AI{\textquoteleft}ed with semen from either a Finn or a Romney ram at set times (49 or 56h) after CIDR removal. AI was spread over 4 days in each of two consecutive weeks. Rams were used on each alternative day. Ewes were checked for return to service to determine pregnancy. There was a significant (P<0.001) difference between rams in pregnancy rate (Finn =35.6 and Romney =52.5\%). There was an effect (P<0.001) of inseminate dose (25 = 55.5 {\textpm} 2.6\%; 5 = 45.2 {\textpm} 2.6\%; 1 = 37.2 {\textpm} 2.6\% and 0.5 = 37.5 {\textpm} 2.6\%). However there was a suggestion of an overall dose by ram interaction with the Romney semen maintaining higher fertility at lower dose levels. There were no effects of inseminator or of diluent. Time from CIDR removal to oestrus had a significant (P<0.05) effect. Time to onset of oestrus was affected by CIDR type. While there was no overall effect of CIDR type on fertility, there was a significant (P<0.05) interaction between sperm dose and CIDR type. These results indicate that acceptable (>50\%) fertility can be achieved with sperm dose rates as low as 1.0x106 if semen quality is satisfactory thus increasing the number of inseminates per ejaculate 20-50 fold. Improved synchrony methods seem imperative to obtaining better fertility from AI. },
	issn = {1176-5283},
	author = {Smith JF and Parr J and Murray GR and Clarke A and Oliver JE and McDonald RM and Duganzich DM}
}
@conference {41023,
	title = {Effect of sperm dose, diluent type and timing of insemination on pregnancy rates in sheep.},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {58},
	year = {1998},
	month = {Jan},
	pages = {186-188},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Low sperm numbers and ambient temperature storage are two important factors in the successful AI system for dairy cattle in New Zealand. Similar technologies with ram semen are required before the establishment of a similar AI system within the NZ sheep industry is feasible. A trial involving a total of 1200 Romney ewes was conducted in April 1997 to examine the effects of inseminate dose (50, 25, or 5 x 10--6 sperm) of semen held for up to 9 h at 20{\textdegree}C in two diluents (RSD-1 and Tris + egg yolk). In the first half of the trial ewes were laparoscopically inseminated with semen from Finn rams at set times (49 and 56 h) after CIDR removal, while in the second half of the trial ewes were inseminated with semen from Romney rams following the detection of oestrus, after CIDR removal, resulting in insemination times of 26, 44 and 49 h post removal. Returns to service in the cycle following AI were recorded and ewes were scanned for pregnancy 50 days post AI. There was a significant difference between ram breeds in pregnancy rate (Finn 63.2 \% v Romney 50.2 \% ; P<0.05). There were no effects of inseminate dose nor of diluent. Time to onset of oestrus was affected by ewe live weight (P<0.05) with the heavier ewes showing a trend for an earlier onset but there was no overall effect of ewe weight on fertility. The effect of time to onset was reflected in an effect of time from CIDR removal to AI in the second half of the trial, with ewes AI{\textquoteright}d within 30h of CIDR removal having a 10\% lower fertility. These results indicate that acceptable fertility can be achieved with semen dose rates 5 to 10 fold less than normal, thereby increasing the number of inseminations available per ejaculate. Improved synchrony methods seem imperative to obtaining better fertility from AI. },
	issn = {1176-5283},
	author = {Smith JF and Parr J and Murray GR and Clarke A and Oliver JE and Duganzich DM}
}
@conference {41022,
	title = {Relationships between laboratory measures of ram sperm competence and field fertility.},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {58},
	year = {1998},
	month = {Jan},
	pages = {181-185},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Previous work has show poor relationships between the maintenance of sperm motility and fertility after AI of ram semen. New laboratory tests of sperm competence have been developed but their relationship to fertility needs to be established. Two large scale trials involving the laboratory evaluation of straws of frozen semen from different rams and the field AI of ewes with the same batches of semen were conducted. In Trial A, 1671 ewes were AI{\textquoteleft}d with 52 batches of semen from 26 rams on 6 farms. In Trial B 6872 ewes were AI{\textquoteleft}d with 137 batches of semen from 34 rams on 25 farms. In Trial A, there was no linkage between farms while in Trial B the same batch was used on more than one farm and most farms had more than 1 batch from more than 1 ram. Laboratory evaluation involved: visual motility assessment post thaw and time taken to drop to 5\% motility when incubated at 38{\textdegree}C, 8 parameters of velocity and direction of motility using CASA; \% live and \% acrosome intact and sperm concentration. These parameters were measured immediately post-thaw and in Trial B a repeat measurement was made after 6h at 38{\textdegree}C. In addition, in Trial A the relative IVF value was determined. In Trial A there were significant (P<0.05) between farm and ram within farm effects on fertility (\% pregnant) but no ejaculate within ram effect. Significant (P<0.001) differences were seen in all semen parameters except initial motility, time to 5\% and concentration. Parameters correlated with fertility were IVF and \% live and together these accounted for 44 \% of the variation. In Trial B, there were effects of farm on fertility (P<0.001) and breed of ram (P<0.05), residual ram variation was non-zero but not significant. There were significant differences between rams and between ejaculates within rams in concentration, visual motility, \% live, velocity and directional parameters. The number of live and motile sperm inseminated was correlated (P<0.001) with fertility. Significant (P<0.05) correlations were also obtained between two CASA parameters; the \% live and \% visual motility, after 6h of incubation. Multiple regression equations were derived that accounted for between 62 and 75 \% of the variation between rams. },
	issn = {1176-5283},
	author = {Smith JF and Parr J and Murray GR and Clarke A and McDonald RM and Duganzich DM}
}
@conference {40949,
	title = {Changes in the activities of plasma membrane bound sperm enzymes during semen processing.},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {57},
	year = {1997},
	month = {Jan},
	pages = {251},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {The physico-chemical changes in spermatozoa that take place during semen processing and storage regulate the fertilising ability of spermatozoa. Spermatozoa1 motil-ity, traditionally used as a marker of fertilising ability, does not indicate the true fertilising ability of spermatozoa (Smithet al., 1993),although motility is required for in  vivo fertilisation. In this study we have monitored changes in activities of spermatozoa1 enzymes at various stages of semen processing. In future, these changes could be corre-lated to fertilising ability. It is also anticipated, that the information on these enzymes would improve our under-standing of basic sperm physiology.},
	issn = {1176-5283},
	author = {Oliver JE and Upreti GC and Duganzich DM and Smith JF}
}
@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 {40953,
	title = {Seasonal Patterns in Production and Quality of Semen of Rams from Flocks Selected for or against an Early Breeding Season.},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {57},
	year = {1997},
	month = {Jan},
	pages = {259},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Seasonal patterns of semen production and sperm quality from rams of different breeds have been previously reported (Colas, 1979). Flocks within a breed have been selected for differences in seasonal lambing patterns based on ewe lambing date (Smith, et al.,1992). This trial reports the effects of this selection on the production and quality of semen from rams in those flocks.},
	issn = {1176-5283},
	author = {Smith JF and Parr J and Smith JK and Briggs RM and Duganzich DM}
}
@conference {40859,
	title = {Brief Communication: Effect of lipids on ram spermatozoal motility},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {56},
	year = {1996},
	month = {Jan},
	pages = {365-366},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Lipids from egg yolk, milk and coconut were toxic to ram  spermatozoal motility. The toxicity of egg yolk lipid was associated with the  neutral lipid fraction. Motility was prolonged in the presence of coconut  lipid.},
	issn = {1176-5283},
	author = {Upreti GC and Hicks K and Oliver JE and Briggs RM and Duganzich DM and Smith JF}
}
@conference {40855,
	title = {Brief Communication: The effect of inorganic ions on ram sperm motility using Computer Assisted Sperm Analysis (CASA)},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {56},
	year = {1996},
	month = {Jan},
	pages = {353-354},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {The role of specific inorganic ions in the maintenance of ram sperm  motility in a chemically defined ram semen diluent (RSD-1) was examined.  A preliminary experiment identified that magnesium was required to  maintain motility. Significant treatment and incubation effects were  observed for all motility parameters (P<.05). RSD-1 (treatment T1) was  modified to provide a series of treatments. Effects measured were the  substitution of MgCl2 (T2) or MgSO4 (T3) and the elimination of KH2PO4  (T4) or NaHCO3 (T5). A total of 10 ejaculates were analysed using the  Hobson Sperm Tracker (HST) over a period of 7 days. Semen was cooled to  15 C after dilution with treatment diluents and reheated to 38 C after 1 hr  and 5 days storage. Motility was measured after incubation at 38 C for 0,  24, and 48 hours. Treatments had a significant (P<0.001) effect on the  velocity parameters and the percentage of motile sperm. Treatments T4 and  T5 had greatest depression in motility parameters with fresh semen while T5  also had an effect with stored sperm. Substitution of the MgSO4 (T3)  reduced the velocity parameters in the fresh semen e.g. mean Curvilinear  velocity (VCL) values (},
	issn = {1176-5283},
	author = {Briggs RM and Upreti GC and Smith JF and Duganzich DM}
}
@conference {40843,
	title = {Effect of selection for early lambing on the testicular diameter of the male offspring},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {56},
	year = {1996},
	month = {Jan},
	pages = {310-313},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Testicular size has been linked to reproductive efficiency and changes  in testicular size could provide an early indicator for the choice of ram  lambs to be used in flocks selecting for out-of-season breeding ability. For 3  years, 20 ram lambs from each of the BV(DL)-ve (earlier lambing) and  BV(DL)+ve (later lambing) flocks at Ruakura were monitored for testicular  diameter (TD) and liveweight (LWT) from weaning until November the  following year. In 1991 and 1992, BV(DL) class and season of birth were  confounded while in 1993 both BV(DL) classes were represented in both  seasons of birth (Autumn and Spring). At the same age Autumn born BV(DL)-ve rams had larger (P<0.05) TD than  did Spring born BV(DL)+ve rams in all years. For the 1993 born lambs, the  shape of the TD growth curve was different for each BV(DL) x season of  birth sub-class (P<0.001). However, at any single age point the within sub- class variation in TD (rsd = 4.6 mm) was such that no meaningful selection  for BV(DL) could be made within rams for that season of birth. Liveweight  interacted with TD and this effect was also influenced by the season of birth. These data indicate that while TD is influenced by season of birth, the  difference in TD between ram lambs of divergent BV(DL; selection for out- of-season breeding ability) was not sufficient for TD to be a useful  parameter for early selection. },
	issn = {1176-5283},
	author = {Smith JF and Parr J and Duganzich DM}
}
@conference {40697,
	title = {Effect of selection for early lambing on the expression of hogget oestrus activity},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {55},
	year = {1995},
	month = {Jan},
	pages = {154-156},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {The effect of grazing parasitised ewe lambs on herbages with and  without condensed tannins (CT},
	issn = {1176-5283},
	author = {Smith JF and Parr J and Murray G and Harris C and Duganzich DM}
}
@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 {40719,
	title = {Seasonal changes in LH profiles of ewes selected for and against an early lambing date},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {55},
	year = {1995},
	month = {Jan},
	pages = {224-227},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	issn = {1176-5283},
	author = {Smith JF and Briggs RM and Parr J and Johnson DL and Duganzich DM}
}
@conference {40600,
	title = {Prediction of beef carcass yield from selected commercial cuts expressed as a percentage of side weight},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {54},
	year = {1994},
	month = {Jan},
	pages = {205-208},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Given that almost all beef carcasses intended for export from New  
Zealand are boned out into cuts in the boning room of export plants, the  
feasibility was investigated of carrying the identification of individual animals  
from the point of slaughter through to sides in the boning room and using the  
weights (percentages) of selected cuts to predict the yield of saleable meat.  A  
Ruakura beef cuts database with information from sides of 1461 bulls, 1097  
steers, 320 heifers and 329 cows, all of known breeding, was used to test the  
accuracy of beef saleable meat yield prediction from the weights of three  
hindquarter cuts removed at the same time and site in the boning room.  The  
inside round (topside), outside round (silverside) and thick flank expressed as a  
percentage of side weight were chosen for use alone and in multiple regression  
to predict the percentage of the carcass available as saleable meat.  A model  
incorporating \% inside and \% outside and their interactions with sex (bull,  
steer, heifer and cow) provided useful prediction of \% meat yield (R2 0.77,  
RSD 2.11\%) and if hot carcass weight was added to the equation the R2  
improved to 0.78 and the RSD was reduced to 2.06\%.  The sum of the inside  
and outside expressed as a percentage of side weight gave the same accuracy of  
prediction of percentage saleable meat yield as when they were treated as  
separate independent variables.  The use of thick flank gave no improvement in  
prediction.  These results should be compared with the present system where  
sex class, fat class (grade) and hot carcass weight predicted yield with an R2  
of 0.60 and an RSD of 2.80\% for the same set of data. },
	issn = {1176-5283},
	author = {Kirton AH and Bass JJ and Hogg BW and Mercer GJK and Duganzich DM and Woods EG}
}
@conference {40512,
	title = {The date of onset of puberty in ewe lambs as an indicator of the ability to breed out-of-season},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {53},
	year = {1993},
	month = {Jan},
	pages = {299-302},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Half-sib heritability estimates were derived from ewe lamb progeny of the Woodlands Romney selection project. Ultrasonic subcutaneous fat depths (C) were measured with a Delphi probe at 5, 6, 8 and 14 months of age.  Heritability estimates at each age were 0.31 (SE=0.12), 0.45 (0.11), 0.29 (0.06) and 0.28 (0.09) respectively. A Toshiba Sonolayer SAL-22A B-mode ultrasonic scanner was used to measure muscle width (A), depth (B) and GR tissue depth at 14 months of age and resultant heritability estimates were 0.07 (0.05), 0.26 (0.09) and 0.39 (0.11), respectively. Genetic correlations among ultrasonic fat depths at different ages ranged from 0.81-0.95 (SE 0.06-0.12) with higher values for those of closer temporal separation. Phenotypic correlations were consistently about 0.3 below the corresponding genetic correlations. Ultrasonic GR had a high heritability estimate and a high genetic correlation with fat depth at 14 months of 0.84 (0.08),but its genetic correlations with fat depths at earlier ages, were lower ranging from 0.55 to 0.72. The genetic correlation of hogget fleece weight with fat depth at 8 months of age was 0.09 (0.15), and the genetic correlation between 8 month liveweight and fat depth was 0.38 (0.13); similar relationships were found for fat depths measured at other ages. The heritability estimate for muscle depth B was moderate and close to that reported for carcass measurements. In contrast, the estimate for muscle width A was lower than reports for carcass measurements perhaps reflecting limitations in the ultrasonic technology used. The results indicate that ultrasonic measurements are useful selection criteria in breeding programmes to alter carcass traits.},
	issn = {1176-5283},
	author = {Smith JF and Parr J and Johnson DL and Duganzich DM}
}
@conference {40534,
	title = {The use of commercial grading probes for classifying lamb carcasses},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {53},
	year = {1993},
	month = {Jan},
	pages = {393-396},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {North American wapiti (Cervus elaphus sub species)_ evolved within, and inhabit, an extremely varied environment generally not apparent within any pastoral farm environment. Normal farm management practices also reduce disease and predation; modify or prevent behavioral strategies such as migration, wallowing and isolation at calving; impose artificial mate selection; result in the removal of antlers in velvet, and premature dissociation of familial groups. Whilst the object of these practices is to utilise deer for animal production, primarily meat and velvet antler, the vast changes imposed will undoubtedly result in rapid changes in genetic, physiological, morphological and behavioral characteristics of the animals. Deer provide a unique opportunity to study and manipulate the effects of farming in a large ruminant, but at the same time the ecological requirements of the animal should be considered.},
	issn = {1176-5283},
	author = {Kirton AH and Mercer GJK and Duganzich DM and Uljee AE}
}
@conference {40372,
	title = {A comparison between subjective and objective (carcass weight plus GR or the Hennessy Grading Probe) methods for classifying lamb carcasses},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {52},
	year = {1992},
	month = {Jan},
	pages = {41-44},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Stress research in farm animals is becoming increasingly  important as a result of public concern for the welfare of animals and  the ongoing need to increase the efficiency of animal production.  Changes in the behaviour of animals is often the first indicator that a  particular farming practice may be aversive or stressful. For example,  cattle housed indoors on concrete floors have fewer resting bouts than  those on deep litter or at pasture. Subsequent measurement of a variety  of physiological parameters confirmed that lying down on slatted floors  is stressful. Changes were noted in the episodic secretory pattern of  glucocorticosterioid hormone, in the cortisol response to challenge with  a standard dose of ACTH (1-24) and in heart rate.   Ongoing studies with dairy cattle indicate that the frequencies and  types of fly-avoidance behaviours utilised by animals without tails  differ from those with tails. In addition, animals without tails have a  higher number of flies on the body. Physiological parameters will be  monitored to determine if the decreased ability of cattle without tails  to remove flies results in altered physiological responses indicative of  stress.   These studies show that a multi-disciplinary approach is required to  quantify the relative stressfulness of various farming practices.  },
	issn = {1176-5283},
	author = {Kirton AH and Mercer GJK and Duganzich DM}
}
@conference {40158,
	title = {Meat yields and chemical composition of muscle in New Zealand goats},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {49},
	year = {1989},
	month = {Jan},
	pages = {153-156},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Three data sets comprising 2329, 2102, and 720 Angora goats sired by 30, 29 and 17 bucks used in the Land Corporation{\textquoteright}s Waitangi Angora flock, were used to obtain estimates of the effects of age, of dam, sex, rearing rank and birth day (age). Characters studied (and years of birth) in the three data sets were: Set 1: weaning weight and 12-month fleece weight (1978-1986); Set 2: 6-month fleece weight and yearling fleece weight (the sum of both 6- and 12-month fleece weights; 1978-1985); Set 3: 12-month live weight and 12-month fibre measurements of fibre diameter, standard deviation of fibre diameter, percent medullation and percent kemp (1984-1986). The weaning weights of kids out of dams aged 3, 4, 5 and 6 + years were heavier than those out of 2-year old dams by 0.7, 1.0, 1.5 and 1.8 kg respectively (P<0.001). Corresponding differences in 6-month fleece weight were 0.01, 0.02, 0.03 and 0.03 kg (P<0.05). Age-of-dam effects were variable for 12-month live weight and arcsine-transformed percent kemp, and nonsignificant for the remaining traits studied. Males had heavier live weights and fleece weights than females (P<0.001), but differences between the sexes were generally small for the fibre measurement traits. Multiple-reared kids (and later-born kids) had significantly lighter live weights and fleece weights than single-reared kids (and earlier-born kids). Both rearing rank and birth day effects were generally small and not significant for the fibre measurement traits. Heritability estimates for weaning weight, 6-, 12-month and yearling fleece weights, 12-month live weight, fibre diameter and standard deviation of fibre diameter were respectively 0.10, 0.24, 0.25, 0.36, 0.24, 0.51 and 0.21. Arcsine transformation of percent medullation and percent kemp data yielded heritabilities of 0.16 and 0.02 respectively. Subject to the limited number of sires represented in the data sets studied, genetic correlations between 12-month fleece weight and the two live weight traits were negative and of medium magnitude. There were also strong positive genetic correlations between 12-month fleece weight and both fibre diameter and arcsine- transformed percent kemp. Phenotypic correlations among live weight, fleece weight, and fibre diameter traits were all positive and of medium to high magnitude. Corresponding correlations with arcsine-transformed percents medullation and kemp were generally small and positive. It was concluded that direct incorporation of the genetic and phenotypic parameter estimates obtained in this study into selection index calculations, could not be advocated without due attention to the limited sample sizes and associated errors of estimation.},
	issn = {1176-5283},
	author = {Hogg BW and Catcheside LM and Mercer GJK and Duganzich DM}
}
@conference {40154,
	title = {Variation in composition and eating quality of New Zealand export beef},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {49},
	year = {1989},
	month = {Jan},
	pages = {133-136},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {An experiment ran from mid-October to mid-January to develop pasture height/quality guidelines for optimum doe and kid growth in spring and to test the advantages of integrating goats with other stock classes at this time. Three goat-only farmlets comprised two paddocks with does and kids alternating, 7 days in each. Pre-grazing pasture mass was maintained at 1.6, 2.0 and 2.5 t DM/ha respectively. In three integrated-species farmlets, does with kids grazed from a pre-graze pasture mass of 2.5 t DM/ha for 7 days, followed by the sheep/cattle mob for 7 day. Paddocks were spelled for three weeks before goats were reintroduced. Sheep/cattle mobs comprised, hoggets, yearling steer, or 60\%/40\% combination of the two (respectively). In goat-only farmlets, does lost live weight and kid liveweight gain was reduced when pre-graze pasture mass was below 2.5 t DM/ha. Doe liveweight gain was maximised in the goat/sheep/cattle farmlet. Kid liveweight gain was compromised only on the lowest pasture mass, gain on other farmlets being similar. Sheep and cattle liveweight gains appeared to be unaffected by grazing behind goats when grazing down to 1.5 - 1.6 t DM/ha. Parasite faecal egg concentration (FEC) of does was increased by grazing at low pasture masses with 80\% and 63\% of does being drenched at 1.6 and 2.0 t DM/ha respectively compared to 53\% at 2.5 t DM/ha. Integration with cattle and sheep/cattle reduced FEC (27\% and 17\% does drenched respectively) compared with goats only or goats followed by sheep (53\% and 43\% respectively). In all farmlets without sheep grazing, weed occurrence on transect analysis was over 35\%. The presence of sheep reduced this to approx. 23\% and in the goat/sheep/cattle system weed occurrence was approx. 10\%. Clover occurrence was similar in all farmlets (approx. 50\%) except for the goat/sheep farmlet (approx. 30\%).},
	issn = {1176-5283},
	author = {Hogg BW and Catcheside LM and Mercer GJK and Duganzich DM and Keiler AH and Ireland TL and Hagyard CJ}
}
@conference {40089,
	title = {The influence of breed on the meat content of beef carcasses for export},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {48},
	year = {1988},
	month = {Jan},
	pages = {57-60},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {A 2 x 2 x 4 factorial trial was performed (n=20), N=320) to investigate the effect of 2 levels of nutrition (high protein diet -23\% crude protein v low protein diet - 10\% crude protein) on the ovarian response to exogenous follicle stimulating hormone (FSH) administration in mixed-age Coopworth ewes. Two preparations of FSH were examined (FSH-P, Burns-Biotec and Folltropin(r), Vetripharm) at 4 different levels (0, 8, 16 and 24 mg equivalents FSH-P). The ovulation rate of both high and low protein intake ewes increased linearly in response to increasing FSH levels (0 mg = 1.2; 8 mg = 3.2; 16 mg = 7.9; 24 mg = 9.6). There was no difference in response between the 2 sources of FSH. Ewes on a high protein intake had a higher ovulation rate when FSH was not administered (mean ovulation rate },
	issn = {1176-5283},
	author = {Butler-Hogg BW and Morris CA and Baker RL and Bass JJ and Mercer G and Duganzich DM}
}
@conference {39994,
	title = {Prediction of ewe mutton carcass composition from carcass weight, GR and C measurements, and the Hennessy grading probe},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {46},
	year = {1986},
	month = {Jan},
	pages = {59-62},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Fourteen herd-years of data, comprising a total of 2169 records, were obtained from beef heifers involved in the Ruakura Genetics Section{\textquoteright}s long term breeding trials. The contributions of breed-cross, weight selection , herd year, birth date and age of dam, to variation in live weight, proportion exhibiting oestrus and proportion pregnant were studied. For heifers reaching first oestrus by about 15 months of age, means ages and weights at puberty were also calculated. Later-born calves were younger and lighter at puberty than average. Younger dams produced heifer offspring which reached puberty when older but lighter than average. Breed and location differences were greater for proportions of heifers expressing oestrus before joining than for proportions pregnant. At Goudies, the proportion achieving oestrus among Jersey x Angus heifers was 0.72, Friesian-cross 0.61, Hereford x Angus 0.47, Hereford 0.38 and Angus 0.25. Corresponding proportions diagnosed pregnant after 8 weeks of mating were 0.83, 0.93, 0.83, 0.78 and 0.73. Where there were major feed shortages over an extended period between 5 and 15 months of age, live weights and pubertal age were more affected than pubertal weight. In contrast, long term weight selection increased pubertal weight by 11\%, while pubertal age was little changed. Preliminary estimates of heritability for pubertal age and weight were 0.31},
	issn = {1176-5283},
	author = {Kirton AH and Feist CL and Duganzich DM}
}
@conference {39948,
	title = {Display life of frozen lamb chops. Effect of breed, sex, packaging film and temperature at packaging},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {45},
	year = {1985},
	month = {Jan},
	pages = {81-84},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Effects of shearing and restricted feeding on the weight and leanness of lamb carcasses were measured in 3 experiments. Changes in fat measurements were parallel to and consistent with changes in carcase weight except where shearing and restricted feeding were combined. The 2 treatments together resulted in carcasses about 1 mm GR leaner than expected for their weight. Shearing following by mild underfeeding was more effective than either procedure alone in reducing fat cover and may increase the market value of overfat lambs.},
	issn = {1176-5283},
	author = {Moore VJ and Duganzich DM}
}
@conference {39944,
	title = {Prediction of lamb carcass composition from GR and carcass weight},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {45},
	year = {1985},
	month = {Jan},
	pages = {63-66},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {A lean-growth index (LGI) incorporating growth rate and the proportion of that growth which is fat is calculated by first converting live-weight differences into differences in weight of lean tissue and then adjusting these values using an estimated breeding value for fat depth. The adjustment of fat depths for weight is by within-flock double-log regression or by specifying a constant exponent in the relationship between fat depth C and live weight. Simulation studies suggested that the constant-exponent method was superior for smaller groups of sheep. Improvements in LGI by selection appear more likely to arise from genetic increases in growth rate than from decreases in weight-corrected fatness, but the inclusion of fatness in the index should lead to the production of lambs that can be taken to heavier weights before becoming overfat.},
	issn = {1176-5283},
	author = {Kirton AH and Duganzich DM and Feist CL and Bennett GL and Woods EG}
}
@conference {39942,
	title = {Swimming speed and fertilisation rates of ram sperm from high and low prolificacy populations},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {45},
	year = {1985},
	month = {Jan},
	pages = {55-58},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {The composition of 2 groups, comprising 70 and 837 lamb carcasses, was predicted from hot carcass weight (HCW) and GR separately and together, these being the main observations considered in the export lamb carcass grading system. GR was a better predictor of composition than HCW with the 2 in combination tending in most cases to be slightly better than GR alone. These measurements could account for 50 to over 70\% of the variation in carcass fat and bone and 26 to 47\% of the variation in carcass muscle. On average, for each 1 mm decrease in GR, carcass fatness decreased by about 1 percentage unit, muscle increased by about 0.5 percentage units and carcass bone increased by just under 0.5 percentage units.},
	issn = {1176-5283},
	author = {Moore RW and Wilson MC and Duganzich DM}
}
@conference {39924,
	title = {Dressing percentages of lambs},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {44},
	year = {1984},
	month = {Jan},
	pages = {231-234},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Overseas comparisons have indicated sheep breeds and strains with improved growth rates and lean meat production to those currently available in New Zealand.  Most studies in U.K. and Eire have generally shown fastest growth and lean tissue gain amongst offspring by the large down breeds, the Suffolk and Oxford. These results are generally comparable with New Zealand studies. In addition, there has been considerable European interest shown in the Texel for its high yield of lean relative to fat and bone, including lean yield in high value areas of the carcass. The white fleece and moderate fecundity of this breed also favour its maternal use to improve flexibility of lean lamb production. In most studies in the U.S. crossbred lambs sired by Suffolk rams fastest to reach slaughter weights before other meat breeds. This breed is of widespread popularity for lamb production in the U.S.  Indirect comparisons suggest a greater growth superiority (5\%) of crossbred lambs sired by U.S. Suffolks overseas compared with those sired by New Zealand Suffolks in this country.},
	issn = {1176-5283},
	author = {Kirton AH and Carter AH and Clarke JN and Duganzich DM}
}
@conference {39835,
	title = {Comparison of well and poorly muscled lamb carcasses as selected by experienced meat industry personnel},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {43},
	year = {1983},
	month = {Jan},
	pages = {111-114},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Ten lambs and 10 kids were offered a low quality meadow hay (7.1 gN/kg/DM) for 12 weeks. Five of each species were then reallocated to lucerne hay (23.8 gN/kg/DM) and the remainder maintained on meadow hay. Feed was offered ad libitum. Digestibility was determined at weeks, 4, 6, 10 and 16. Animals were fed at 2 h intervals prior to slaughter and the retention time of dry matter in the rumen estimated. Body energy changes were estimated by comparative slaughter. In the initial 6 weeks kids and lambs digested meadow hay to a similar extent but whereas it was maintained in kids, digestibility by lambs subsequently declined until week 16. At week 16 values for dry matter digestibility were 0.67 and 0.54 for kids and lambs, respectively. There were no significant differences in the digestibility of lucerne hay between the species nor in the voluntary intake of meadow hay or lucerne hay. Both species consumed more lucerne hay than meadow hay. Kids retained lucerne hay longer than did lambs (18.,7 h and 11.8 h, respectively) but meadow hay had a similar retention time in both species (24.7 h and 27.8 h, respectively). Water intake of lambs was approximately double that of kids. Difficulties in determining maintenance energy requirement from body weight change are discussed.},
	issn = {1176-5283},
	author = {Kirton AH and Woods EG and Duganzich DM}
}
@conference {39785,
	title = {Comparison of backfat depth probes for use in pig carcass grading},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {42},
	year = {1982},
	month = {Jan},
	pages = {119-120},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Objective measurements in cattle accounted for a significant percentage of the variation of hindquarter muscle weight after adjustment for weight of hindquarter and within the N.Z. export P grade. The conformation measurements on lamb accounted for only a small percentage of the variation of the weight of muscle and fat-free frozen carcass weight. Objective conformation measurements in cattle may be of use in a grading system unlike the conformation measurements taken in sheep.},
	issn = {1176-5283},
	author = {Adam JL and Duganzich DM and Hargreaves K}
}
@conference {39804,
	title = {Influence of feeding post-lambing on ewe and lamb performance at grazing},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {42},
	year = {1982},
	month = {Jan},
	pages = {179-182},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {No abstract supplied},
	issn = {1176-5283},
	author = {Rattray PV and Jagusch KT and Duganzich DM and MacLean KS and Lynch RJ}
}
@conference {39721,
	title = {The effect of season of the year and pasture allowance on the growth of lambs fed different pasture species - Brief Communication},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {41},
	year = {1981},
	month = {Jan},
	pages = {117-118},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	issn = {1176-5283},
	author = {Jagusch KT and Duganzich DM and Winn GW and Rattray PV}
}
@conference {39738,
	title = {Interrelationships of placental development with nutrition in pregnancy and lamb birth weight},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {41},
	year = {1981},
	month = {Jan},
	pages = {218-223},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	issn = {1176-5283},
	author = {Davis SR and Rattray PV and Petch ME and Duganzich DM}
}
@conference {39709,
	title = {Production differences between Jersey and Friesian x Jersey cows in commercial dairy herds},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {41},
	year = {1981},
	month = {Jan},
	pages = {48-52},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	issn = {1176-5283},
	author = {Macmillan KL and Duganzich DM and Bryant AM}
}
@conference {39247,
	title = {The effect of two different planes of nutrition from conception to four years of age on the maintenance requirements and on the efficiency of wool growth},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {28},
	year = {1968},
	month = {Jan},
	pages = {74-82},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	issn = {1176-5283},
	author = {Wodzicka-Tomaszewska M and Bigham ML and Kirton AH and Duganzich DM}
}
