@conference {3672, title = {Analysing hidden patterns of farmers{\textquoteright} preferences for farm performance characteristics that may be related to tail-docking practice decisions}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {205-209}, address = {Dunedin}, abstract = { We investigated how multivariate statistics can be used to determine the different patterns of preferences that may exist within a farmer population. As a case study, we used adaptive conjoint analysis to analyse farmers{\textquoteright} preferences for nine farm performance characteristics that may be related to tail docking practice decisions. As expected, at the whole population level, farmers{\textquoteright} preferences for these traits were found to be highly heterogeneous, with only the most important issues and least important issues being able to be statistically differentiated. Using Cluster Analysis and Principal Components Analysis we found some hidden relationships and identified the existence of four groups of farmers that had greater preferences for different characteristics; group one preferred having less dags and less costs associated with dagging and crutching, group two preferred to reduce euthanasia from uterine prolapse and rectal prolapse, group three preferred to avoid stressing lambs at the time of docking and group four preferred to have less fly-strike and greater weaning weights. We discuss how the use of multivariate statistics allowed a deeper interpretation of preference studies in a context of importance to NZ farmers.}, issn = {1176-5283}, author = {Martin-Collado D and Byrne TK and Amer PR and Behrent MJ and Maclennan G and Kerslake JI} } @conference {3672, title = {The effect of grazing high-sugar ryegrass on lamb performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {235-238}, address = {Dunedin}, abstract = { A multi-year grazing study was undertaken on three commercial properties in the southern South Island to compare the performance of lambs grazing high-sugar ryegrass/white clover (HSG) with lambs grazing a standard ryegrass/white clover pasture (SRG). Cultivars were established in late spring 2012; approximately 400 lambs in each treatment group per property grazed the swards in autumn 2013 and summer/autumn 2014 at a density of 30 to 35 lambs per hectare. Lambs were weighed regularly throughout the season; those that reached the desired weight were sent for slaughter. Across both years and properties, lambs grazing the HSG pasture grew 31 grams per day faster (17\%) on average than those grazing SRG (P<0.001). These lambs were an average of 0.4 kg heavier in terms of carcase weight at slaughter (P<0.001) yielding 0.2 kg more meat per carcase based on VIAScan yield. These results suggest that lambs grazing HSG outperform those grazing SRG.}, issn = {1176-5283}, author = {Proctor LE and Craig HJB and McLean NJ and Fennessy PF and Kerslake JI and Behrent MJ and Chuah JCL and Campbell AW} } @conference {3672, title = {Effect of shearing on lamb growth and carcase performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {215-218}, address = {Dunedin}, abstract = { A study was undertaken on three properties throughout New Zealand to determine the impact of shearing on lamb performance and whether this offered any economic benefit to farmers as a farm-management tool. A total of 1,183 lambs were randomly allocated to one of four treatments, shorn fasted, bellied fasted, woolly fasted and woolly not fasted. Shorn fasted lambs grew 12 g/d faster than woolly fasted lambs (P<0.05), but at similar rates to bellied lambs and woolly not fasted lambs. There were no differences among treatments for carcase weight, meat yield or proportion of lambs killed at slaughter. The difference observed in average daily gain between the shorn fasted and the woolly fasted lambs, and the lack of difference observed between shorn fasted and woolly not fasted lambs, indicated that while shearing improved lamb growth rates, the weight loss due to fasting overnight was not overcome by the increased growth rate associated with shearing. While there was no economic benefit associated with lamb carcase weight or time to slaughter, at a wool price of $5.40 per kg clean, shorn lambs were still of a greater value to farmers compared to lambs from all other treatments.}, issn = {1176-5283}, author = {McLean NJ and Craig HJB and Fennessy PF and Behrent MJ and Kerslake JI and Campbell AW} } @conference {3672, title = {The reasons farmers choose to dock lamb tails to certain lengths, or leave them intact}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {210-214}, address = {Dunedin}, abstract = { Compared to a survey carried out in 2005, New Zealand farmers appear to be docking fewer lamb tails flush (6\% vs. 22\%) and docking a greater number of lamb tails at 4-7 cm length (32\% vs. 16\%). The main reasons for docking were to minimize fly strike risk, reduce accumulation of dags and keep the crutching costs down. Farmers who docked lamb tails to a shorter length (3-4 cm) gave significantly (P<0.05) more importance to minimizing fly-strike, reducing the likelihood of dags and reducing the cost of crutching than any other reason. Farmers who docked lamb tails at a longer length (4-7 cm) gave significantly (P<0.05) more importance to meeting the processor requirements, minimizing euthanasia from uterine prolapse and minimizing fly-strike risk than any other reason. When farm performance characteristics, that may influence decisions relating to tail docking practices, were prioritised by farmers, preferences for minimizing deaths from fly-strike, improving weaning weight and making more money from the processor were greater than having fewer dag events, less euthanasia from rectal prolapses and less stress for the lamb at docking. These preferences did not differ among farmers that dock tails at different lengths or leave them intact.}, issn = {1176-5283}, author = {Kerslake JI and Bryne TJ and Behrent MJ and Maclennan G and Martin-Collado D} } @conference {89240, title = {Ewe live weight and body condition in mid-to- late-pregnancy does not affect the maximum heat production capacity of its lamb at birth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {143-145}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Under pastoral conditions, lambs are often exposed to wind, cold and rain that result in neonatal mortality. Thus any improved thermoregulatory response has the potential to increase lamb survival. Especially in light lambs, there is a strong negative relationship between birth weight and mortality (Everett-Hincks \& Dodds 2008). Birth weight also regulates the lamb{\textquoteright}s thermoregulatory capability (Kerslake et al. 2010). Lamb birth weight is influenced by ewe live weight, ewe bodycondition score and the variation in these parameters (Everett-Hincks \& Dodds 2008; Schreurs et al. 2012). Therefore, ewe live weight and ewe body condition score may influence the thermoregulatory capability of the newborn lamb and its survival to weaning.

}, issn = {1176-5283}, author = {Martin NP and Kenyon PR and Hickson RE and Kerslake JI and Morris ST} } @conference {79004, title = {Does castration status have an effect on the quality of lamb meat?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {144-146}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Consumer demand for leaner lamb meat all-year-round and price incentives to produce heavier carcases means that in New Zealand ram lambs are often being left entire in an attempt to improve lamb growth rates (Fisher et al. 2010). While this offers potential improvements in on-farm returns, there are still perceived concerns in the market place that meat from entire ram lambs of a certain age may be unsatisfactory. Based on the latest scientific evidence (Young et al. 2006; Young et al. 2003) New Zealand processors make no distinction between carcasses from lambs of different genders. However, due to continual perceived concerns from consumers, ... continued}, issn = {1176-5283}, author = {Kerslake JI and Hely FS and Maclennan G and Lindsay S and Behrent MR and Campbell AW} } @conference {79006, title = {Exploring the effects of growth rate and meat yield on lamb meat quality}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {150-151}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

New Zealand sheep breeding programs currently place high emphases on selection for growth and yield. High growth rates and high meat yield have both been reported as having negative effects on meat quality in pig, beef and poultry (Dransfield \& Sosnicki 1999), probably due to changes in muscle structure and metabolism. In contrast, organic pork has shown to be less tender than conventional pork, which is thought to be due to organic pigs growing more slowly (Therkildsen et al. 2012). It is of importance to evaluate these relationships in lamb.

}, issn = {1176-5283}, author = {Campbell AW and Maclennan G and Lindsay S and Behrent MR and Cheong I and Kerslake JI} } @conference {75906, title = {BRIEF COMMUNICATION: The effects of different forage types on lamb performance and meat quality}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {208-210}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {

Meat quality is made up of a number of traits, with colour at the point of purchase, being perceived as the main indicator of freshness. The traits of aroma, flavour, succulence, and texture influence the eating experience and the probability of repurchase. A number of factors influence meat quality traits, including environmental factors such as... Continued.

}, issn = {1176-5283}, author = {Campbell AW and Maclennan G and Judson HG and Lindsay S and Behrent MR and Mackie A and Kerslake JI} } @conference {75892, title = {Continuing to increase productivity while maintaining our clean green image. Introductory remarks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {149}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {An increase in intensive livestock farming can help our agricultural industry increase the production of more affordable food products. Unfortunately it can also have a negative impact on our environment and consequently the overall acceptance of our food products by the international consumer. To retain our position as leaders of premium quality agricultural food products, the New}, issn = {1176-5283}, author = {Kerslake JI} } @conference {75924, title = {Physical and physiological factors associated with twin- and triplet-born lamb heat production at 24 to 36 hours of age}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {286-290}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {This study attempted to identify physical and physiological factors of twin- and triplet born lambs within the first 24 to 36 hours of life which are associated with maximum heat production on a per lamb basis (W/lamb) and a per kg of birth weight basis (W/kg). Multiple regression analyses revealed that lamb birth weight accounted for 34 percent of the variation in maximum heat production on a per lamb basis (P <0.001), whereas, inclusion of plasma non-esterified fatty acids (NEFA; P <0.01), tri-iodothyronine (T3; P <0.05) and glucose concentrations at 24 to 36 hours of age (P <0.05) increased the accountability to 59 percent. Multiple regression analyses also revealed that plasma NEFA concentrations at 24 to 36 hours of age accounted for 15 percent of the variation in maximum heat production on a per kg of birth weight basis (P <0.01), whereas, inclusion of plasma T3 at 24 to 36 hours of age increased the accountability to 22 percent (P <0.05). Overall these results suggest that having greater lamb birth weights, plasma thyroid hormone, glucose and NEFA concentrations at 24 to 36 hours of age is beneficial for twin- and triplet-born lamb thermoregulation during periods of cold stress.}, issn = {1176-5283}, author = {Kerslake JI and Kenyon PR and Morris ST and Stafford KJ and Morel PCH} } @conference {41701, title = {Parturition duration and birthing difficulty in twin and triplet lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {55-60}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {The primary objective of this study was to investigate the relationship between parturition duration, localised oedema in lambs (as determined by post mortem findings) and lamb survival. Parturition behaviour was recorded for 131 mixed age Coopworth ewes and their 303 lambs (twins n=180; triplets n=123). Twin lambs and first born triplet lambs that did not survive tothree weeks of age took at least twice as long to be born than lambs that survived (P<0.05). The duration of parturition for lambs that died and had moderate to severe subcutaneous oedema was more than three times longer than for those that had none and minor localised subcutaneous oedema at post mortem examination (P<0.05). Further research is required to understand the factors contributing to prolonged parturition for twins and triplets. This information is needed so that appropriate management techniques and animal breeding programmes can be developed to reduce birthing difficulties (dystocia) and lamb mortality rates.}, issn = {1176-5283}, author = {Everett-Hincks JM and Dodds KG and Kerslake JI} } @conference {41529, title = {Lamb survival: a new examination of an old problem}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {13-18}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The overall aim of this project is to identify genetic markers for lamb survival. This paper reports the results from the first stage of the investigation aimed to identify the primary causes of lamb death from parturition to three days of age for highly fecund flocks. Flocks in the study consisted of 9 breeds and 12,000 breeding ewes and were located in New Zealand regions; Southland, Otago and Manawatu. All lambs were tagged and identified to their dam and sire. Lambs dead at birth and up to three days of age were collected (n = 1529), weighed, measured and examined by post mortem to determine cause and time of death. Primary causes of lamb death included: dystocia, starvation/exposure, amnion over nose, organ rupture, disease, and unknown. The mean mortality rate from birth to weaning for the 20 flocks studied was 14 {\textpm} 0.6\% (SEM) in singles, 16 {\textpm} 0.3\% in twins and 29 {\textpm} 0.6\% in triplets. The study showed that the predominant primary cause of lamb deaths from parturition to three days of age was dystocia (difficult births). The dystocia rate was highest for dead single lambs (57 {\textpm} 4.2\% SEM) (P < 0.05), where there was an unexpectedly high incidence for dystocia for dead twin (46 {\textpm} 1.7\% SEM) and triplet lambs (48 {\textpm} 2.3\% SEM). This suggests that dystocia as a primary cause of lamb death may be underestimated within highly fecund sheep flocks. The high death rate from dystocia in twin and triplet lambs has not been previously reported and is currently under further investigation. KEYWORDS: lamb survival; dystocia; post-mortem; cause of death; mortality; genetic; phenotypic. }, issn = {1176-5283}, author = {Kerslake JI and Everett-Hincks JM and Campbell AW} }