Browsing by Author "Hickson R"

Now showing 1 - 15 of 15
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    Assessing Extensive Semi-Arid Rangeland Beef Cow-Calf Welfare in Namibia. Part 2: Categorisation and Scoring of Welfare Assessment Measures
    (MDPI (Basel, Switzerland), 2021-01-20) Kaurivi YB; Laven R; Hickson R; Parkinson T; Stafford K
    This paper aims to develop standards for a welfare assessment protocol by validating potential categorisation thresholds for assessing beef farms in various beef cow-calf production systems in Namibia. Forty measures, combined from a New Zealand-based protocol plus Namibia-specific measures, are applied to 55 beef farms (17 commercial farms, 20 semi-commercial and 18 communal village farms) during pregnancy testing, and a questionnaire guided interview. The categorised measures on a 3-point welfare score (0: good, 1: marginal, and 2: poor/unacceptable welfare) are subsequently compared with the derivation of thresholds based upon the poorest 15% and best 50% of herds for each measure. The overall combined thresholds of continuous measures across the three farm types show 10/22 measures that posed welfare compromise across Namibia, whereas commercial farms have 4/22 measures, and semi-commercial and communal village farms have 12/22 and 11/22, respectively, with high thresholds. Most measures-imposed thresholds are retained because of significant importance to the welfare of animals and preventiveness of the traits, while leniency was given to adjust good feeding and mortality measures to signify periods of drought. Handling measures (fearful, falling/lying) and abrasions thresholds are adjusted to reflect the temporary stress caused by infrequent cattle handling, and faulty yard designs/design and possible cattle breed influence on handling. Hence, Namibia needs prioritised investigation of underlying contributing factors and remediation to reduce the high thresholds.
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    Assessing Extensive Semi-Arid Rangeland Beef Cow-Calf Welfare in Namibia: Part 1: Comparison Between Farm Production System's Effect on the Welfare of Beef Cows
    (MDPI (Basel, Switzerland), 2021-01-12) Kaurivi YB; Laven R; Parkinson T; Hickson R; Stafford K
    A proposed animal welfare assessment protocol for semi-arid rangeland-based cow-calf systems in Namibia combined 40 measures from a protocol developed for beef cattle in New Zealand with additional Namibia-specific measures. Preliminary validation of the protocol had been undertaken with five herds in one semi-commercial village. The aim of the current study was to apply this protocol and compare animal welfare across three cow-calf production systems in Namibia. A total of 2529 beef cows were evaluated during pregnancy testing in the yards of 17 commercial, 20 semi-commercial, and 18 communal (total: 55) herds followed by an assessment of farm resources and a questionnaire-guided interview. Non-parametric tests were used to evaluate the difference in the welfare scores between the production systems. The results indicated a discrepancy of animal welfare between the three farm types, with a marked separation of commercial farms from semi-commercial, and communal village farms in the least. The differences in these production systems were mainly driven by economic gains through access to better beef export market for commercial farms and semi-commercial villages, as well as by the differences in the available grazing land, facility designs/quality, and traditional customs in the village systems. The results indicate an advantage of commercialization over communalization.
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    Development of LIME-NZ: a generic tool for prompt estimation of economic impacts of disease for New Zealand livestock.
    (Taylor and Francis Group, 2024-02-04) Wada M; Compton C; Hickson R; Bingham P
    AIMS: To develop a simple and robust generic tool to measure the impacts of livestock diseases on New Zealand dairy, beef and sheep farms using enterprise gross margin models. METHODS: The most recent (2018-2020) livestock production benchmarking data was extracted from industry-led economic surveys. Gross margin models were built for each enterprise type, accounting for 11 dairy farm types and 16 farm types for beef and sheep. Disease parameters, including changes in mortality, reproduction performance, milk yield, price of animals and culling rate, as well as additional expenses for veterinary intervention, were applied to the infected compartment of the herd/flock using the assumed annual within-herd disease incidence. Farm-level disease impacts were estimated as the difference in annual profit between the baseline and infected farm. The baseline gross margin models were validated against the industry data. The disease impact models were validated using a recently published study on bovine viral diarrhoea (BVD). The impact assessment tool, LIME-NZ, was developed using the statistical software R and implemented in the web-based R package Shiny. The input parameters can be varied interactively to obtain a range of disease impacts for uncertain disease parameters. RESULTS: The baseline gross margin models demonstrated reasonable accuracy with a mean percentage error of <14% when compared with the industry reports. The estimated annual impacts of BVD were comparable to those reported in the BVD study, NZ$38.5-140.4 thousand and $0.9-32.6 thousand per farm per year for dairy and beef enterprises, respectively. CONCLUSIONS: LIME-NZ can be used to rapidly obtain the likely economic impacts of diseases that are endemic, recently introduced or at increased risk of introduction in the New Zealand context. This will aid communication and decision-making among government agencies and the livestock industry, including veterinarians and livestock producers, about the management of diseases, until refined information becomes available to improve decision-making.
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    Effect of Animal Welfare on the Reproductive Performance of Extensive Pasture-Based Beef Cows in New Zealand
    (MDPI (Basel, Switzerland), 2020-12-11) Kaurivi YB; Laven R; Parkinson T; Hickson R; Stafford K
    One key area where animal welfare may relate to productivity is through reproductive performance. This study assesses welfare on 25 extensively managed pastoral New Zealand beef farms, and explores the relationship between welfare and reproductive performance. Relationships between welfare measures and key reproductive performance indicators (pregnancy rate, weaning rate, mating period and bull: cow ratio) are investigated using an exploratory principal components analysis and linear regression model. Seven welfare measures (thinness, poor rumen fill, dirtiness, blindness, mortality, health checks of pregnant cows and yarding frequency/year) showed a potential influence on reproductive performance, and lameness was retained individually as a potential measure. Mean pregnancy rates, in both 2018 (PD18) and 2017 (PD17), were ~91% and mean weaning rate was 84%. Of the welfare measures, only lameness had a direct association with pregnancy rate, as well as a confounding effect on the association between mating period and pregnancy rate. The bull: cow ration (mean 1:31) and reproductive conditions (dystocia, abortion, vaginal prolapse) did not influence pregnancy and weaning rates. In the study population, there was no clear association between welfare and reproductive performance, except for the confounding effects of lameness.
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    Estimated Breeding Values of Beef Sires Can Predict Performance of Beef-Cross-Dairy Progeny
    (Frontiers Media S.A., 2021-09-30) Martín N; Coleman L; Lopez-Villalobos N; Schreurs N; Morris S; Blair H; McDade J; Back P; Hickson R
    On average, half of the animal’s estimated breeding value (EBV) is passed on to their progeny. However, it is not known how the performance of beef-cross-dairy cattle relates to the EBV of their beef sire. Such information is required to determine the genetic potential of beef sires selected based on existing EBV to be used on dairy cows in New Zealand. This study evaluated the relationship between the EBV of 30 Angus and 34 Hereford sires and the performance of their progeny for birth, growth, and carcass traits, via progeny testing of 975 beef-cross-dairy offspring born to dairy cows and grown on hill country pasture. Overall, BREEDPLAN EBV did predict progeny performance of the beef-cross-dairy cattle from this study. Gestation length and birthweight increased with increasing sire EBV (mean 0.37–0.62days and 0.52–0.64kg, respectively, p<0.05). Age at weaning decreased with increasing sire EBV for liveweight at 200days (0.17–0.21days per extra kilo of sire EBV, p<0.05) but sire EBV for liveweight at 200days had no effect on the liveweight of the progeny at 200days for either breed (p>0.05). Liveweight increased with sire EBV for liveweight at 400, 600, and 800days, by a similar amount for both breeds (between 0.23 and 0.42kg increase in progeny liveweight per extra kilo of sire EBV, p<0.05). The relationships were more inconsistent for carcass traits. For Hereford, carcass weight and eye muscle area increased with increasing sire EBV (0.27kg and 0.70cm2, respectively, p<0.05). For Angus, marble score increased by 0.10 with 1% extra in sire EBV for intramuscular fat (p<0.05). Rib fat depth tended to increase with sire EBV for both breeds (p<0.1). EBV derived from beef-breed data work in dairy-beef systems but maybe slightly less than the expected 0.5units of performance per unit of EBV. New Zealand farmers should consider BREEDPLAN EBV when selecting sires to mate dairy cows or when buying beef-cross-dairy calves for beef production, to ensure the resulting calves are born safely and on time and then grow well to produce carcasses of suitable meat and fat composition.
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    Genetic susceptibility to Theileria orientalis (Ikeda) in Angus- and Hereford-sired yearling cattle born to dairy cattle on an endemically infected farm in New Zealand
    (Taylor and Francis Group, 5/03/2023) Lawrence K; Fermin L; Gedye K; Hickson R; lawrence B; coleman L; Pomroy W; Natalia M; Lopez- Villalobos N
    Theileria orientalis (Ikeda) was first detected in New Zealand in 2012, becoming endemic in most of the North Island, and can cause incidences of anaemia and death. Research has been performed in New Zealand on the incidence and severity of infection. Through this research anecdotal evidence has been found to suggest a potential genetic susceptibility component in the response of the host to the parasite. To investigate the genetic susceptibility of cattle to T. orientalis (Ikeda), 99 calves born in 2016 as part of a separate experiment and grown in six grazing herds, were examined for their response to the parasite. In addition to measuring live weight, two blood collections were taken in the first four months of life which were used to measure packed cell volume by haematocrit and qPCR to assess parasite load. Heritability was calculated and was low for parasite load, but the result indicates that there is some potential to increase resistance through selective breeding. The mechanisms of the differences in parasite load were not elucidated in this research; however, significant variation was found among herds and sires, indicating that both genetic selection and environmental management could be utilised to reduce parasite load in growing calves.
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    Low Birthweight Beef Bulls Compared with Jersey Bulls Do Not Impact First Lactation and Rebreeding of First-Calving Dairy Heifers—A Case Study in New Zealand
    (MDPI (Basel, Switzerland), 2022-03) Coleman L; Martín N; Back P; Blair H; López-Villalobos N; Hickson R; Bittante G; Mantovani R
    Dairy heifers in New Zealand are typically naturally mated by Jersey bulls to produce low-value non-replacement offspring sold for slaughter a few days after birth. Producing a beef-sired calf from a dairy heifer will increase the value of these calves for beef production but may compromise the subsequent career of the animals, in terms of milk production, rebreeding success, health, or survival of the heifer. This study aimed to determine the impact of low birthweight Angus and Hereford bulls versus breed-average Jersey bulls on the reproduction and production traits of first-calving dairy heifers. The experiment included 304 heifer-calf pairs over 2 years. Calves sired by Angus and Hereford bulls were 3.5–4.4 kg and 3.7–6.8 kg heavier than Jersey-sired calves and had a 4.2% and 9.3% incidence of assistance at birth for normally presented calves over the 2 years, respectively. No normally presented Jersey-sired calves were assisted. There was no difference in body condition score, pre-calving live weight, milk production, pregnancy rate, inter-calving interval, re-calving day, and 21-day re-calving rate of heifers mated to the different breeds of bulls. The results indicate that the Angus and Hereford bulls with low birthweight and high direct calving ease estimated breeding values (EBV) can be used to produce calves of greater value than Jersey-sired calves without impacting dairy heifer production. However, a small increase in assistance at calving could be expected.
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    Service Sire Effects on Body Condition Score, Milk Production, and Rebreeding of Mixed-Aged Dairy Cows Bred to Angus and Hereford Bulls—A Case Study in New Zealand
    (MDPI (Basel, Switzerland), 2021-12-01) Coleman L; Back P; Blair H; López-Villalobos N; Hickson R; Meyer U
    Beef-breed bulls are used in dairy herds to produce a calf of greater value for finishing than calves sired by dairy bulls. There is limited research about which beef-breed bulls are most appropriate, and whether any negative impact on cow performance in terms of milk production and rebreeding should be considered. The aim of this case study was to compare the body condition score, milk production, and rebreeding performance of mixed-aged dairy cows bred to a selection of Angus and Hereford beef-breed bulls. Body condition score, post-calving live weight, milk production, rebreeding performance, and survival of 952 mixed-aged dairy cows artificially bred to 65 Angus and Hereford bulls were compared. There was no effect of service sire on post-calving live weight, days in milk, milk production, or inter-calving intervals of mixed-aged cows. Service sire had an effect on the calving day due to differences in gestation length (p < 0.001), although this did not translate into an effect on days in milk. A longer gestation length negatively influenced pregnancy rates, and greater birth weight of the calf negatively influenced survival to rebreeding (p < 0.05), indicating the potential for an effect of service sire. Selection of beef-breed service sires for dairy cows should include emphasis on lighter calves and shorter gestation lengths. The general absence of the service sire effect on the parameters measured in this study indicated that any of the service sires used in this experiment would be appropriate for use over dairy cows.
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    Sire Effects on Birth Weight, Gestation Length, and Pre-Weaning Growth of Beef-Cross-Dairy Calves: A Case Study in New Zealand
    (MDPI (Basel, Switzerland), 2021-09-01) Coleman L; Back P; Blair H; López-Villalobos N; Hickson R; Meyer U
    Production of beef-cross-dairy calves from dairy cows increases the value of non-replacement calves born to the dairy herd. The use of beef-breed sires may impact on calf birth weight, gestation length and pre-weaning growth rate of calves, which in turn influences the profitability of the dairy farm. The aim of this case study was to compare the birth weight, gestation length, and pre-weaning growth of progeny born to mixed-aged dairy cows on a single farm which were artificially bred to a selection of Angus and Hereford bulls, typical of those used over dairy herds in New Zealand. The birth weight, gestation length and pre-weaning growth of 980 calves sired by 65 sires were compared. Mean progeny birth weight (range 33.3–41.4 kg), gestation length (range 276.1–288.6 days), age at weaning (range 70.3–88.3 days) and pre-weaning ADG (range 0.63–0.76 kg/d) differed among sires (p < 0.001). There was a negative genetic correlation (−0.31) and positive phenotypic correlation (0.36) between gestation length and birth weight. Age at weaning was negatively correlated with birth weight (genetic: −0.56, phenotypic: −0.57). Bulls used in this study, and other bulls with similar genetic merit for birth weight and gestation length would be suitable for mating mixed-aged dairy cows in New Zealand.
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    Sire Effects on Carcass of Beef-Cross-Dairy Cattle: A Case Study in New Zealand
    (MDPI (Basel, Switzerland), 2021-03) Martin N; Schreurs N; Morris S; Lopez-Villalobos N; McDade J; Hickson R
    There is interest in increasing the carcass value of surplus calves born in the dairy industry that are reared for beef production in New Zealand. This experiment evaluated the carcass of Angus and Hereford sires via progeny testing of beef-cross-dairy offspring grown on hill country pasture. Weight and carcass traits were analyzed from 1015 animals and 1000 carcasses of 73 sires. The mean of the progeny group means was 567 kg for live weight at slaughter, 277 kg for carcass weight, 48.9% for dressing-out, 240.3 cm for carcass length, 73.6 cm2 for eye muscle area, 7.4 mm for rib fat depth, 0.91 for marble score, 3.05 for fat color score, 3.01 for meat color score, and 5.62 for ultimate pH. Sire affected (p < 0.05) carcass size and fat traits, but not fat color, meat color, or ultimate pH (p > 0.05). There was a 46 kg increase in carcass weight between the best and worst sires tested. Carcass fat traits were the most variable among sires. The use of genetically superior beef-breed sires over dairy-breed cows has the potential to increase carcass weights from surplus calves born in the dairy industry, while maintaining adequate fat levels and carcass quality.
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    The Effect of Age of Dam and Birth Rank on the Reproductive Performance of Ewes as One- and Two-Year-Olds.
    (10/03/2021) Pettigrew E; Hickson R; Morris S; Kenyon P; Corner-Thomas R; Haslin E; Blair H
    Currently, 30-43% of New Zealand sheep farmers breed their ewe lambs, but few retain the offspring as replacements for their flock. No difference in lamb production as a yearling among singletons and twins born to ewe lambs and twins born to mature ewes has been reported, provided the ewe lambs had reached the 60-65% of their likely mature weight prior to breeding at seven to eight months of age. The aim of this experiment was to determine the lamb production from singletons and twins born to ewe lambs and twins born to mature ewes during their first two years of lambing. The experiment included 8-month-old ewes born as twins to mature ewes (M2, n = 135), singletons born to ewe lambs (L1, n = 135), and twins born to ewe lambs (L2, n = 88), bred during the same period to the same rams, over two years. The efficiency of lamb production (total litter weight at weaning divided by the pre-breeding weight of the ewe, for all ewes presented for breeding) after two years of production was not significantly different (p > 0.05) among the groups (0.40 ± 0.02, 0.39 ± 0.02, and 0.39 ± 0.03, for M2, L1, and L2, respectively).
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    The Effect of Sex and Age on Bone Morphology and Strength in the Metacarpus and Humerus in Beef-Cross-Dairy Cattle
    (MDPI (Basel, Switzerland), 2021-03-05) Gibson M; Hickson R; Back P; Dittmer K; Schreurs N; Rogers C
    In cattle, limited data have been reported about the relationship between live weight, bone size, and strength and how this relationship can be altered by factors such as sex and age. The aim of this study was to describe the relationship of peripheral quantitative computed tomography (pQCT)-derived parameters of bone strength and morphology with live weight, age and sex in beef-cross-dairy cattle. All animals were weighed the day before slaughter. The metacarpus and humerus were collected at slaughter and scanned at the mid-diaphysis using pQCT. Live weight was the primary explanatory variable for bone size and strength in all cohorts. However, the effect of age was significant, such that magnitude of response to liveweight was less in the 24-month-old cohort. Sex was significant within cohorts in that bulls had a shorter metacarpus than steers and heifers had a shorter metacarpus than steers at age of slaughter.
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    The Mid-Diaphysis Is a Poor Predictor of Humeral Fracture Risk Indicating That Predisposing Factors Are Recent
    (MDPI (Basel, Switzerland), 2021-09) Gibson M; Dittmer K; Hickson R; Back P; Wehrle-Martinez A; Rogers C; Bonanno A
    The incidence of spontaneous humeral fractures in first-lactation dairy heifers in New Zealand has emphasised the need to understand the thoracic limb bone growth of dairy heifers. Previous research has indicated that a predisposing factor to spontaneous humeral fracture is nutrition. In addition, it has been hypothesised that liver copper concentration affects bone strength and may be a potential factor associated with humeral fracture risk. The aim of this study was to compare bone morphology in the mid-diaphysis of the metacarpus and humerus of heifers affected and unaffected by spontaneous humeral fractures, and determine the effect of copper status at death on bone morphology. The metacarpus and humerus were collected from heifers affected and unaffected by humeral fractures, and scanned using peripheral quantitative computed tomography (pQCT). The mid-diaphysis of the humerus of the affected group had reduced cortical bone mineral density and a trend for reduced cortical content and total bone content, which contributed to a reduced stress–strain index. The trend for reduced bone length in affected humeri provides additional support for the hypothesis of inhibited humeral growth. Heifers with low copper liver concentrations had reduced humerus lengths and reduced cortical bone mineral densities. These data support the hypothesis that the developmental window for humeral fracture is recent, and possibly associated with periods of inadequate nutrition.