Journal Articles

Permanent URI for this collectionhttps://mro.massey.ac.nz/handle/10179/7915

Browse

Filters

2019 - 201912020 - 20246

Settings

Has files: YesSubject: search.filters.subject.lamb

Search Results

Now showing 1 - 7 of 7
  • Thumbnail Image
    Item
    The influence of the number of lambs present on the suckling behaviour of triplet-rearing ewes at pasture
    (Taylor and Francis Group, 2024-01-01) Corner-Thomas RA; Shanks R; Beausoleil NJ; Sneddon N
    This study examined the suckling behaviour of triplet-rearing ewes for three days post-parturition. Twenty-six ewes were enrolled with 11 being observed for the entire 3-days post-lambing. The behaviour of the ewe, number of lambs present at the end of the event and the behaviour that terminated the event were recorded for each suckling event. The mean suckling event duration increased when additional lambs were present at the end of the suckling event. Ewes that had observations across all three days showed no change in the number of suckling events over time, but suckling events tended to be shorter on day 3 than on days 1 or 2. On day 1 more suckling events were terminated by the ewe walking away from her lambs than on days 2 and 3. The odds of a ewe walking away to terminate the suckling event were greater when three lambs were present compared with two. Ewes showed more inactive behaviours when more lambs were present at the end of the suckling event. The results partially supported the hypothesis that the ewe would be more likely to terminate a suckling event when three lambs were attempting to suck compared with one or two lambs.
  • Thumbnail Image
    Item
    Comparison of meat quality characteristics of lambs weaned at eight or 14 weeks of age grazing perennial ryegrass-white clover or a plantain-clover mix
    (New Zealand Society of Animal Production, 2019-07) Kok JC; Schreurs NM; Cranston LM; Corner-Thomas RA; Ekanayake WEMLJ; Morris ST; Kenyon PR
    This study compared the meat quality of lambs grazing either perennial ryegrass-white clover pasture or a plantain-clover mix (plantain, red clover, and white clover) from eight to 14 weeks of age followed by a six-week finishing period on perennial ryegrass-white clover pasture. Ewes and their lambs were allocated to four treatments: 1) lambs weaned early (eight weeks of age) on a plantain-clover mix (EARLY), 2) lambs with dam grazing a plantain-clover mix (HERB), 3) lambs with dam grazing pasture >1200 kgDM/ha (HIGH), and 4) lambs with dam grazing pasture <1200 kgDM/ha (LOW). Following the treatment period, all lambs weighing a minimum of 35 kg were sent for slaughter and all remaining lambs were managed and finished as one mob on perennial ryegrass-white clover pasture for a further six weeks. Lambs that reached a minimum 35 kg live weight were slaughtered and meat samples from each lamb were analysed for ultimate pH, meat colour (L*, a*, b*), drip loss and shear force but, no difference was found in objective meat quality characteristics of lambs from different treatments.
  • Thumbnail Image
    Item
    Increased Dietary Protein to Energy Ratio in Pre-Weaning Lambs Increases Average Daily Gain and Cortical Bone Thickness in the Tibia
    (MDPI (Basel, Switzerland), 2022-12) Gibson MJ; Adams BR; Back PJ; Dittmer KE; Herath HMGP; Pain SJ; Kenyon PR; Morel PCH; Blair HT; Rogers CW
    The objective of this study was to examine if diets differing in crude protein (CP) to metabolizable energy (ME) ratio (CP:ME) pre-weaning altered peripheral quantitative computed tomography (pQCT) measures of bone mass and strength in lambs. The left hind leg of lambs were available at the completion of a trial designed to examine the effect that altering the CP:ME ratio in milk replacer had on growth and body composition of pre-weaned lambs reared artificially. Treatments consisted of either normal commercial milk replacer (CMR, n = 10) containing 240 g/kg CP and 21.89 MJ/kg ME, high protein milk replacer (HPM, n = 9) containing CMR with additional milk protein concentrate to reach 478.7 g/kg CP and 19.15 MJ/kg ME or a mix of normal milk replacer and milk protein concentrate adjusted twice-weekly to match optimal CP:ME requirements (MB, n = 8) based on maintenance plus 300 g/d liveweight gain. At 22 kg live weight, lambs were euthanized and the tibia including the surrounding muscle was collected and scanned using pQCT at the mid-diaphysis. Lambs on the HPM and MB diets had a greater average daily gain (p < 0.01). There were limited differences in bone morphology and muscle mass, though notably the higher protein diets (MB and HPM) were associated with greater cortical thickness (p < 0.05) and, therefore, potentially greater peak bone mass at maturity This finding demonstrates that pre-weaning diets, and the protein content in particular, may influence the developmental potential of long bones and attainment of peak bone mass at maturity.
  • Thumbnail Image
    Item
    Predicting the Feed Intake of Artificially Reared Pre-Weaned Lambs from Faecal and Dietary Chemical Composition
    (MDPI (Basel, Switzerland), 2022-06) Anim-Jnr AS; Morel PCH; Kenyon PR; Blair HT; Leury BJ
    Predicting feed intake in suckling lambs consuming both milk and pasture can be challenging, and thus intake values are often derived from solely milk or solid feed consumption. The present study investigated if dry matter (DM), organic matter (OM), and metabolisable energy (ME) intakes of lambs given a combination of milk and pellets under controlled conditions could be predicted with enough precision using dietary and faecal chemical composition. A total of 34 pre-weaned lambs bottle-fed milk replacer with or without access to pellets and kept in metabolic cages for four days were used. To develop the prediction equations, 54 faecal samples with detailed information on their chemical compositions, and the feed consumed by the lambs, were used. Pellet DMI was predicted from neutral detergent fibre concentration in faeces and pellets, pellets %DM, and live weight (LW) of lambs. Milk DMI was predicted from faecal Nitrogen concentration and LW. Milk and pellet DMI and their ME content were combined to predict DMI/d and ME intake/d. The equations developed were validated against 40 spot faecal samples randomly selected from the lambs. DM, OM, and ME intakes were predicted with high accuracy and precision. The results showed that the developed equations can be used with enough accuracy to predict ME, OM, and DM intakes in pre-weaned lambs ingesting milk and pellets concurrently, thus the results revealed that the established equations may be used to predict ME, OM, and DM intakes in pre-weaned lambs drinking milk and pellets at the same time, allowing feeding regimens for young lambs to be developed.
  • Thumbnail Image
    Item
    The Effect of Artificial Rearing on Live Weight Gain and Bone Morphology of the Tibia in Lambs Prior to Weaning
    (MDPI (Basel, Switzerland), 2022-03) Gibson MJ; Rogers CW; Pettigrew EJ; Pain SJ; Dittmer KE; Herath HMGP; Back PJ; Leury BJ
    Growth rates associated with different artificial rearing systems have been thoroughly examined in many species. However, the effect of different rearing systems on bone morphology has not been described. The objective of this study was to examine differences in the bone mass and the relationship of peripheral quantitative computed tomography (pQCT) measures of bone with muscle area of ewe-reared lambs and artificially reared lambs. Lambs were opportunistically collected from a concurrent trial examining changes in ewe mammary glands during lactation. Thirteen lambs were artificially reared while the remaining nine were left on their dam. Measures of stature were taken throughout the six-week trial period. At approximately six weeks of age, the lambs were euthanized and the tibia was collected and scanned using peripheral quantitative computed tomography. Artificially reared lambs had reduced live weight gain and an altered pattern of stature growth. There was no effect of treatment on bone morphology (p > 0.05), but ewe reared lambs had a greater cortical bone content to muscle area ratio than artificially reared lambs (0.06 vs. 0.15, respectively). Differences in growth between ewe reared lambs and artificially reared lambs emphasizes the importance of adequate preweaning nutrition for livestock production systems that routinely use artificial rearing systems.
  • Thumbnail Image
    Item
    Proteomic Profile of M. longissimus thoracis from Commercial Lambs Reared in Different Forage Systems
    (MDPI (Basel, Switzerland), 2022-05-13) Ye Y; Maes E; Deb-Choudhury S; Hefer CA; Schreurs NM; Realini CE; Colgrave M; Mora L
    This study compared the protein composition of M. longissimus thoracis of lambs from six commercial forage production systems in New Zealand. A total of 286 proteins were identified based on liquid chromatography-tandem mass spectrometry. First, a binomial model showed that different production groups could be distinguished based on abundances of 16 proteins. Second, pair-wise comparisons were performed to search for protein abundance differences in meat due to animal sex (ewe vs. wether), diet (perennial ryegrass vs. chicory), and age (4 vs. 6-8 months old). Greater abundance of some myofibrillar and sarcoplasmic proteins were observed in lamb loins from ewes compared to wethers. Chicory diet and older age at slaughter were associated with meat with lower abundance of some myofibrillar proteins, possibly due to a greater proportion of muscle glycolytic fibres. The proteins that showed significant differences in their abundances due to production factors could be further investigated to understand their influence on meat quality.
  • Thumbnail Image
    Item
    Factors Associated with Mortality of Lambs Born to Ewe Hoggets
    (MDPI (Basel, Switzerland), 2022-02) Ridler AL; Flay KJ; Kenyon PR; Blair HT; Corner-Thomas RA; Pettigrew EJ
    The reproductive performance of ewe hoggets is poorer than that of mature-age ewes due to production of fewer lambs with poorer survival. Scant data are available on the risk factors for, and causes of, the mortality for lambs born to ewe hoggets, the impact of ewe deaths on lamb loss, and the causes of death for lambs born to ewe hoggets vs. mature-age ewes lambing in the same circumstances. In this study, 297 lambs born to 1142 ewe hoggets were necropsied along with 273 lambs born to 1050 mature-age ewes. Low lamb birthweight, multiple litter size, and increasing ewe hogget average daily gain from breeding to late pregnancy were risk factors for lamb mortality. The most common cause of mortality for lambs born to ewe hoggets was stillbirth and the risk factors for stillbirth were similar to those for lamb mortality generally. Approximately 11% of ewe hoggets’ lamb deaths were due to the death of the dam. Causes of mortality differed between lambs born to ewe hoggets vs. those born to mature-age ewes. Management practices to increase ewe hogget lambs’ birthweights (particularly those from multiple litters) and supervision of ewe hoggets at lambing time are recommended.