Zealand Lamb Research Articles

Bigger lambs or more lambs: The conundrum for New Zealand lamb producers

New Zealand sheep producers generate most of their income from sheep sales, particularly lamb sales. To increase revenue from lamb sales producers have two choices, increase the number of lambs weaned or increase the weight of lambs produced and sold. Lifting the number of lambs sold requires an increase in lambs born per ewe, however this comes at a cost as these lambs are typically smaller and may not reach optimal slaughter weight within the desired timeframe. Alternatively, increasing the weight of lambs, while maintaining total feed supply constant, means that the number of breeding ewes carried on the farm may have to be reduced. This study utilises an existing bioeconomic model to examine the impact on farm productivity and profitability of increasing lambing percentage from an average of 133.5% to 140, 150 or 160%, or increasing lamb weaning weight from 30 kg and 25 kg for singles and twins respectively, by 10, 20 or 30%, or alternatively a mix of the two, i.e., 140% lambing rate and weaning weights of 33 and 27.5 kg for singles and twins, respectively. The results show that lifting lamb weaning weight, by 10, 20 or 30%, increases enterprise cash operating surplus (COS) from $291/ha to $342, $392, or $444/ha, respectively, which is more than the increases in COS from lifting lambing percentage by 10, 20 or 30%, which increased COS to $313, $345, or $368/ha, respectively. The alternative of lifting lambing percentage by 10% and lamb weaning weight to 33 kg and 27.5 kg, increased COS by $74/ha. Overall, increasing pre-weaning lamb growth was more profitable than increasing lambing percentage. Therefore, if a producer has a lambing percentage of 140% or above their focus should be on improving pre-weaning lamb growth rates rather than lifting lambing percentage.

Potential of in-plant intramuscular fat predictions to enable sheep breeders to incorporate consumer preferences in breeding programmes

The inclusion of eating quality traits in sheep genetic improvement programmes is desirable. Intramuscular fat (IMF) plays a key role in ensuring consumer satisfaction when eating lamb, but genetic progress for IMF is constrained by a lack of routine data collection. This study investigated the potential for IMF predictor traits to substitute for measured IMF in genetic improvement programmes. Carcass and predicted IMF (near-infrared estimated IMF and marbling score) data were available on 10,113 New Zealand lambs, 1678 of which also had measured chemical IMF on a slice of M. longissimus lumborum on which the predictions of IMF had been made. Genetic antagonisms were observed between carcass lean traits and IMF. The genetic correlation between the predictors and measured IMF approached one, indicating that predictors of IMF can be used in genetic improvement programmes. Through using selection indexes, simultaneous increases in IMF and the existing terminal selection index are possible, provided all traits are measured. This study highlights the importance and potential of predicted IMF to achieve genetic improvement in traits of importance to consumers.

Doubtful Guests, Harassed Hosts, and the Golden Rule

Doubtful Guests, Harassed Hosts, and the Golden Rule

Cross-Cultural Differences in the Perception of Lamb between New Zealand and Chinese Consumers in New Zealand.

This study investigated differences between general New Zealand consumers and ethnic Chinese consumers living in New Zealand regarding the importance of lamb attributes at the point of purchase and opinions of New Zealand lamb. A central location test survey was undertaken with 156 New Zealand consumers living in Dunedin, New Zealand, and 159 Chinese consumers living in Auckland, New Zealand. In terms of importance at the point of purchase, Chinese consumers rated a number of attributes as more important than New Zealand consumers by a difference of >1.0 on a 9-point Likert scale for importance: animal origin, feeding, age, presence of hormones/residues, traceability, food safety, place of purchase, brand/quality label, and label information (p < 0.05). New Zealand consumers rated the price of other meats and animal welfare as more important than Chinese consumers (p < 0.05); however, the differences in scores were <1.0. In terms of opinions, Chinese consumers also considered New Zealand lamb to be better value for money, more additive-free, and more likely to make people feel good (p < 0.05), by scores >1.0 on a 7-point Likert scale for agreement. New Zealand consumers considered New Zealand lamb more traditional and boring (p < 0.05); however, the differences in scores were <1.0.

Genetic variation in skin traits in New Zealand lambs.

BACKGROUNDThis study explored the genetic variability in the New Zealand sheep population for economically important skin traits. Skins were collected at slaughter from two progeny test flocks, resulting in 725 skins evaluated for grain strain, flatness, crust leather strength and overall suitability for shoe leather. DNA profiles collected from skins post‐slaughter were matched to individual animals using previously collected high‐density genotypes.RESULTSConsiderable phenotypic variation for skin traits was observed, with around 40% of the skins being identified as suitable for high‐value shoe leather production. Several key traits associated with leather production, including flatness, tear strength, grain strength and grain strain were found to be moderate to highly heritable (h 2 = 0.28–0.82).There were no major significant genome‐wide association study (GWAS) peaks associated with many of the traits examined, however, one single‐nucleotide polymorphism (SNP) reached significance for the flatness of the skin over the hindquarters.CONCLUSIONThis research confirms that suitable lamb skins can be bred for use as high‐value shoe leather. While moderately to highly heritable, skin traits in New Zealand lambs appear to be polygenic with no genes of major effect underlaying the traits of interest. Given the complex nature of these traits, the identification and selection of animals with higher‐value skins may be enabled by geomic selection. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

How does maternal genetic merit and country of origin impact lamb performance pre- and post-weaning?

The objective of this study was to investigate the impact of ewe maternal genetic merit and country of origin (New Zealand or Ireland) on lamb growth and performance pre- and post-weaning. The study was conducted from 2016 to 2019, inclusive, and consisted of three genetic merit groups: New Zealand ewes of high maternal genetic merit (NZ), Irish ewes of high maternal genetic merit (High Irish) and Irish ewes of low maternal genetic merit (Low Irish) ewes and their lambs. Each of the genetic merit groups contained 30 Suffolk and 30 Texel ewes, selected based on the respective national maternal genetic indexes; i.e. either the New Zealand Maternal Worth (NZ group) or the Irish €uro-star Replacement Index (Irish groups). The impact of maternal genetic merit on lamb live-weight, average daily gains, age at drafting, ultrasound scanning, and health traits were analysed using linear mixed models. New Zealand lambs were heavier than High Irish lambs at six weeks post-partum (P < 0.05), Low Irish lambs at weaning (P < 0.001) and than both Irish genetic merit groups at ultrasound scanning (P < 0.001) and at drafting (P < 0.05). New Zealand lambs had greater average daily gains at most time points both pre- and post-weaning compared to High Irish and Low Irish lambs. High Irish lambs had greater average daily gains than Low Irish lambs from birth to drafting and from weaning to drafting (P < 0.001). New Zealand lambs had greater muscle depths (P < 0.001), firmer faecal consistency (P < 0.001) and lower dag scores (P < 0.001) in comparison to both Irish genetic merit groups who did not differ from each other (P> 0.05). High Irish lambs had a higher Nematodirus count (P < 0.001) and lamb quality score (P < 0.05) compared to Low Irish lambs. New Zealand lambs were more likely to be drafted from the system by 1st October compared to lambs in the Low Irish genetic merit group (P < 0.001). Lamb mortality from birth to drafting did not differ between any of the three genetic merit groups (P> 0.05). Overall, few differences are reported between the genetic merit groups pre-weaning. However, differences emerged post-weaning between lambs born from ewes of high and low maternal genetic merit and between animals of NZ and Irish origin, demonstrating the potential benefit of their strategic use in the future.

The Implications of COVID-19 on Chinese Consumer Preferences for Lamb Meat.

This study assessed if Chinese consumer attitudes towards a range of lamb attributes (such as origin, food safety, appearance, taste, price), and their opinions of New Zealand lamb (9- and 7-point Likert scales, respectively), had changed since the outbreak COVID-19. The same survey was carried out in Shanghai and Beijing pre (December 2018) and post COVID-19 (November 2020), ~9 months after China’s initial outbreak, with 500 and 523 consumers, respectively. From December 2018 to November 2020, there was an increase in the proportion of Chinese consumers purchasing red meat online or from a butcher, and cooking their lamb well-done. In contrast, there were minimal differences in Chinese consumer ratings between December 2018 and November 2020 for different lamb attributes and opinions of New Zealand lamb. Cluster analysis revealed that many consumers (140 in December 2018/376 in November 2020) used only a small portion of the high end of the scale when rating lamb attributes, resulting in little differences between the attributes. This study suggests COVID-19 has enhanced some food safety related behaviors but had little effect on Chinese opinions and preferences for New Zealand lamb attributes. It also highlights that survey design should be carefully considered when collecting responses from Chinese consumers.

Short communication: Long term performance of near infrared spectroscopy to predict intramuscular fat content in New Zealand lamb

This study investigates the performance of a partial least squares regression model to predict intramuscular fat (IMF) in lamb M. longissimus lumborum developed using near infrared (NIR) data collected under a range of different conditions. A total of 26 independent NIR datasets were collected across 7 years, including 14 flocks, four devices and several measurement conditions. A model is developed and its performance is tested using a total of n = 3201 NIR spectra and intramuscular fat percentage measurements by wet chemistry. The model had a coefficient of determination by cross-validation of 0.52, which agrees with previous results using smaller numbers of animals. Overall the results show that near infrared models can be robust across many varying conditions. These models could potentially be implemented in an automated meat quality monitoring system.

Consumer liking of M. longissimus lumborum from New Zealand pasture-finished lamb is influenced by intramuscular fat

Palatability of meat is known to be affected by intramuscular fat (IMF), but the effect in relatively low-fat New Zealand lamb is unknown. This study evaluated the eating quality of 108 loins (M. longissimus lumborum) from a single flock of ewe-lambs. Loins ranged from 1.09–5.68% IMF and were stratified into 6 groups: 1.65, 2.12, 2.65, 3.20, 3.58 and 4.40%. Consumers' (n = 165) overall liking of lamb increased significantly at around 3% IMF, achieving maximum scores at 4% IMF. One consumer cluster (n = 111) showed a linear increase in overall liking with increasing IMF%, regarded as ‘IMF lovers: the more the better’, while a second cluster (n = 54) preferred 2.5–3.5% IMF, described as ‘IMF optimizers: just the right amount’. IMF% was modestly correlated (~ + 0.25) with all sensory attributes except juiciness. Liking scores were modestly correlated with monounsaturated (~ + 0.25) and polyunsaturated (~ − 0.20) fatty acids. Results suggest aiming for IMF% levels in New Zealand lamb beyond 3% to maximize eating quality for premium markets in particular.

Effect of High Hydrostatic Pressure Processing on the Chemical Characteristics of Different Lamb Cuts.

The non-thermal high-pressure processing (HPP) technique has been used to increase the shelf life of food without compromising their nutritional and sensory qualities. This study aims to explore the potential application of HPP on New Zealand lamb meat. In this study, the effect of HPP, at different pressure treatments (200–600 MPa) on eight different lamb meat cuts in terms of lipid oxidation, fatty acid and free amino acid content were investigated. In general treatments between 400 and 600 MPa resulted in higher oxidation values in eye of loin, flat, heel, and tenderloin cuts. Saturated and monounsaturated fatty acid content were significantly lower with HPP treatment of almost all cuts (except rump and heel cuts) at all pressures. Polyunsaturated fatty acid content was significantly lower in HPP-treated inside, knuckle, and tenderloin cuts at 600 MPa compared to control. Nine essential free amino acids (valine, leucine, isoleucine, methionine, phenylalanine, lysine, histidine, tyrosine and tryptophan), and eight non-essential free amino acids (alanine, glycine, threonine, serine, proline, aspartic acid, glutamic acids and ornithine) were identified in the lamb cuts. HPP increased the total free amino acid composition significantly compared to control at all pressures for almost all cuts except the inside and eye of loin cuts. This study suggests that higher pressure treatments (i.e., 400 and 600 MPa) resulted in higher TBARS oxidation levels. Additionally, significant decreases in saturated and monounsaturated fatty acids and increase free amino acid content were observed in the majority of HPP-treated samples compared to control.

Retail lamb fat composition in western Canada

The fatty acid composition of retail lamb backfat commonly available in Western Canada was analyzed, including 16 lambs collected from a slaughter plant in central Alberta, and backfat collected from racks and chops imported from Australia (n = 8) and New Zealand (n = 8). Lamb fat from New Zealand was the richest source of vaccenic and rumenic acids. Both New Zealand and Australian lamb were the richest source of n-3 fatty acids. North American lamb was richer in t10-18:1, but a subset had fatty acid compositions similar to New Zealand lamb.

US Consumer Assessment of New Zealand Lamb

US Consumer Assessment of New Zealand Lamb

Incidence and heritability of ovine pneumonia, and the relationship with production traits in New Zealand sheep

The cost of ovine pneumonia and pleurisy to the New Zealand economy is high, with the majority of loss through slower growth and reduced carcass value at slaughter. Farm management practices and vaccine development have traditionally been the main focus for prevention of pneumonia. The objective of this study was to estimate the heritability of pneumonia in New Zealand lambs, and investigate the genetic relationship with key production traits.The lungs of 11,437 lambs from pedigree-recorded flocks were scored for the presence and severity of pneumonic lesions at slaughter. On average 28% of lambs had pneumonic lesions at slaughter, with 7% showing severe lesions. The incidence of pleurisy in these animals was 6%. Heritability estimates for pneumonic lesions and pleurisy were 0.07±0.02 and 0.02±0.01, respectively. There was a significant positive genetic correlation between pneumonic lesions and faecal egg count (0.30±0.13). Animals with pneumonic lesions had grown faster from birth to weaning, and slower from weaning to slaughter than animals without lesions.This study has shown that there is a heritable component to pneumonia in sheep. Including more data from pedigree-recorded flocks with severe pneumonia and a high incidence of pleurisy will enable more accurate estimates of genetic parameters, and subsequent correlations with production and disease traits. This would be aided by routine recording of pneumonia in lungs at slaughter by processing plants.

Post-mortem prediction of primal and selected retail cut weights of New Zealand lamb from carcass and animal characteristics

Post-mortem measurements (cold weight, grade and external carcass linear dimensions) as well as live animal data (age, breed, sex) were used to predict ovine primal and retail cut weights for 792 lamb carcases. Significant levels of variance could be explained using these predictors. The predictive power of those measurements on primal and retail cut weights was studied by using the results from principal component analysis and the absolute value of the t-statistics of the linear regression model. High prediction accuracy for primal cut weight was achieved (adjusted R2 up to 0.95), as well as moderate accuracy for key retail cut weight: tenderloins (adj-R2=0.60), loin (adj-R2=0.62), French rack (adj-R2=0.76) and rump (adj-R2=0.75). The carcass cold weight had the best predictive power, with the accuracy increasing by around 10% after including the next three most significant variables.

Derivation of a new lamb survival trait for the New Zealand sheep industry.

Previous research identified that a review of the current industry New Zealand lamb survival trait was necessary as its recording accuracy was reliant on farmers notifying their Sheep Improvement Limited bureau of lamb deaths. This paper reports the decision rules and genetic parameters for a new lamb survival trait for the New Zealand sheep industry. These rules define the new lamb survival trait (NEWSUR) using lamb birth fate (BFATE) codes and the presence/absence of lamb weight measurements. Six univariate animal models were tested and used to estimate variance or covariance components and the resulting direct and maternal heritabilities for NEWSUR. The models differed in the way they adjust for the effect of day of birth, the exclusion or inclusion of a litter (dam/year of birth) random effect, and the application or not of a logit transformation of the phenotypes. For both the linear and logistic methods, models including the random effect of litter provided the best fit for NEWSUR according to log-likelihood values. Log-likelihoods for the linear and logistic models cannot be compared; therefore, a cross-validation method was used to assess whether the logit transformation was appropriate by analyzing the predictive ability of the models. The mean square errors were slightly lower for the linear compared with the logistic model, and therefore, the linear model was recommended for industry use. The heritability attributed to direct effects ranged from 2 to 5.5%. A direct heritability of 5.5% resulted from a linear model without litter effect and omitting the effect of day of birth on survival, whereas a direct heritability of 2% resulted from the logistic model fitting a random litter effect. The heritability attributed to maternal genetic effects ranged from 1.9 to 7.7%. A maternal genetic heritability of 7.7% resulted from the logistic model omitting the litter effect, whereas a maternal genetic heritability of 1.9% resulted from the linear model fitting a random litter effect. The addition of the litter random effect substantially decreased the maternal heritabilities in all cases and was recommended for industry use to avoid overestimation of the maternal genetic variance. Sheep Improvement Limited has implemented NEWSUR and the associated genetic evaluation model based on information described in this paper. Industry-wide implementation will enable sheep breeders to produce more accurate genetic evaluations to their commercial clients.

Conserving Carnivores: Politics in Play

In their Review “Status and ecological effects of the world's largest carnivores” (10 January, DOI: [10.1126/science.1241484][1]), W. J. Ripple et al. propose the creation of a Global Large Carnivore Initiative (GLCI) endorsed by bold commitments from politicians around the world. However, large carnivores deliver political services in addition to ecological services, and this complication may prevent a GLCI from gaining strong political commitment. Conflicts involving the political response to large carnivores raise controversial questions about land-use and political economies. The animals serve as a powerful symbol to communicate difficulties (often those that they revealed but did not create) and to influence policies. Opposing the recovery of large carnivores or limiting their populations has therefore become an inexpensive way for politicians to pose as defenders of particular interest groups that they might otherwise ignore. An illustrative example is the decline of sheep farming in France. French sheep farmers claim that wolf attacks threaten their livelihoods ([ 1 ][2]). However, this story overlooks political factors. In 1985, French Special Forces sank Greenpeace's flagship boat in Auckland harbor to prevent protests against nuclear tests. As part of the compensation, France agreed to not take measures that could hinder the import of New Zealand lambs into the European Union ([ 2 ][3]). This sudden end to France's protectionist standing has been a tough economic challenge for French sheep farming. Since the wolf naturally came back to France from Italy in 1992, some French politicians took the opportunity to stand for national sheep farming by dramatizing the impact of livestock attacks and opposing the wolf return, without addressing the ultimate market-based causes of sheep farming decline. In 2012, wolf-linked subsidies to sheep farming amounted to 8.8 € million ([ 3 ][4]), and data now reveal that sheep farming fares better in wolf regions ([ 4 ][5]). There are strong political incentives to scapegoat large carnivores. We recommend developing a better understanding of the political ecology of large carnivore conservation. 1. [↵][6] 1. S. Sayare , “As wolves return to French Alps, a way of life is threatened,” New York Times, 4 September 2013, p. A4. 2. [↵][7] 1. C. Harding , Singapore Yearbook Int. Law 10, 99 (2006); . [OpenUrl][8] 3. [↵][9] Ministere de l'Ecologie de Developpement Durable et de l'Energie, Ministere de l'Agriculture de l'Agroalimentaire et de la Foret, “Plan d'Action National Loup 2013–2017” (Paris, 2013); [www.loup.developpement-durable.gouv.fr/IMG/pdf/130830\_PLAN\_LOUP_2013-2.pdf][10]. 4. [↵][11] 1. L. Garde 1. L. Garde , in Loup et Elevage: S'Ouvrir a la Complexite: CERPAM—Centre d'Etudes et de Realisations Pastorales Alpes Mediterranee, L. Garde , Ed. (CERPAM, Manosque, France, 2007), pp. 14–20. [1]: /lookup/doi/10.1126/science.1241484 [2]: #ref-1 [3]: #ref-2 [4]: #ref-3 [5]: #ref-4 [6]: #xref-ref-1-1 View reference 1 in text [7]: #xref-ref-2-1 View reference 2 in text [8]: {openurl}?query=rft.jtitle%253DSingapore%2BYearbook%2BInt.%2BLaw%26rft.volume%253D10%26rft.spage%253D99%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [9]: #xref-ref-3-1 View reference 3 in text [10]: http://www.loup.developpement-durable.gouv.fr/IMG/pdf/130830_PLAN_LOUP_2013-2.pdf [11]: #xref-ref-4-1 View reference 4 in text

Association between variation in faecal egg count for a mixed field-challenge of nematode parasites and ovine MHC- DQA2 polymorphism

The selection of sheep that are resistant to gastrointestinal parasites and have lower faecal egg counts (FECs) has been the subject of extensive research. This has led to the speculation that the Major Histocompatibility Complex (MHC) genes could be used as markers to reduce FEC. In this study, associations between variation in ovine MHC- DQA2 and various measures of FEC recorded at two times (approximately 4 and 9 months of age) were investigated in a large group of New Zealand lambs ( n = 4676), derived from 185 different sire-lines, of a variety of breeds and raised on 25 separate farms. Pair-sample t-tests revealed that FEC for Nematodirus spp., Strongyle spp. and total FEC differed significantly between the two assessments. A total of twenty one DQA2 alleles or DQA2– DQA2-like haplotypes were identified, with allele/haplotype presence and frequency varying significantly between farms. For example, allele *0103 was observed on all farms, ranging in frequency from 0.2 to 60.9%, while haplotype *0101–*1601 was only present on one farm, in two lambs. A number of associations between the presence/absence of these alleles and egg counts were observed, but nearly all the allelic/haplotypic associations were age and parasite specific, suggesting that immune response is both age and challenge (parasite species mix) dependent. The exception was allele *1201 which was associated with increased total FECs at both 4 and 9 months of age; with it either being, or tending toward being, significantly associated with both increased Strongyle spp. and Nematodirus spp. counts as well. However, the observed increases in egg counts were small and ranged between 5 and 32 eggs per gram. In conclusion, we believe that the MHC plays an important role in parasite resistance, but that the MHC–nematode interaction is complex and thus the development of a single gene-marker based on the “MHC effect” is unlikely.

Carbon footprinting of New Zealand lamb from the perspective of an exporting nation

Contributors to the carbon footprint of New Zealand lamb exported to the United Kingdom across the life cycle were the cradle-to-farm-gate (80%; mainly animal-related emissions), processing (3%), retail/consumption/waste (12%), and shipping (a small component at 5%). Sheep farming uses low inputs and all-year grazing of perennial grasslands. Nevertheless, large efficiency gains have occurred with a 22% smaller on-farm carbon footprint compared with 1990 from increased lambing percentage and lamb growth rates. In the wider sustainability context of food production, sheep have a low environmental impact and utilize grassland on hills and steepland that have limited other uses.

Hierarchical and spatial analyses of pneumonia-lesion prevalence at slaughter in New Zealand lambs

We recorded lesions of moderate-to-severe pneumonia (≥10% lung surface area affected; “pneumonia”) in 1,899,556 lambs submitted to three New Zealand abbatoirs between December 2000 and September 2001. The average prevalence of pneumonia ranged between 7 and 13%, by abbatoir. We ran a two-level mixed-effects binomial logistic-regression model with the prevalence of pneumonia as the outcome, and adjusting for abbatoir and month. The intracluster correlations for batch (slaughter lambs from the same farm sent at the same time) and farm were 31.3 and 12.4%, respectively. (We also noted threefold differences in odds across abbatoirs, and >30-fold differences among slaughter months.) Case flocks (those in the upper quintile of pneumonia prevalence) generally were not clustered in the spatial incidence-risk analysis (after adjusting for flock-level and batch level effects, and as compared to flocks in the lower two quintiles). We therefore concluded that the risk of moderate-to-severe pneumonia-lesion prevalence detectable at slaughter of lambs was determined at the flock and batch level, rather than at the spatial level.

Marketing New Zealand lamb in the EU

This study replicates work published in 2002, exploring the use of country of origin images in the international marketing of six of New Zealand's primary industry products by agribusinesses. Specifically, this study examines and analyses the use of country of origin in the marketing strategies used by Meat & Wool New Zealand to market New Zealand lamb. Findings from the present study were well aligned with those of the 2002 study by Beaverland and Lindgreen. In particular, the New Zealand lamb-marketing scenario supported the heavy use of country of origin images by specialist marketing boards for niche products. Further, in support of past findings, the use of country of origin was a means of differentiating the product from others in the host market. History was also found to be a contributing factor to how lamb was marketed, though played an indirect role in shaping the attributes of the product that were accentuated by the use of country of origin marketing.