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1.
J Anim Sci ; 1022024 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-38477357

RESUMEN

Fertility is economically important but is hard to quantify and measure in breeding programs which has led extensive breeding programs to ignore fertility in their selection criteria. While female fertility traits have been extensively researched, male fertility traits have been largely ignored. It is estimated that 20% to 40% of bulls have sub-fertility, reducing the number of calves born and profits, highlighting the importance of investigating bull fertility. The most practical measure of male fertility is a bull breeding soundness evaluation (BBSE) which assesses structure as well as semen quality and quantity. Generally, traits recorded in a BBSE are neither genetically evaluated nor used for selection in breeding programs. All traits recorded during a BBSE were analyzed through a series of univariate and bivariate linear mixed models using a genomic relationship matrix to estimate genetic parameters. All genotype and phenotype data were obtained from a tropical composite commercial cattle population and imputed to 27,638 single-nucleotide polymorphisms (SNPs) with a total of 2,613 genotyped animals with BBSE records ranging from 616 to 826 animals depending on the trait. The heritabilities of the 27 traits recorded during a BBSE ranged from 0.02 to 0.49. Seven of the male fertility traits were recommended to be included in a breeding program based on their heritability and their phenotypic and genetic correlations. These traits are scrotal circumference, percent normal sperm, proximal droplets, distal midpiece reflex, knobbed acrosomes, vacuoles/teratoids, and sheath score. Using these seven traits in a breeding program would result in higher calving rates, increasing production and profitability.


One of the key profit drivers in any animal breeding program is fertility as it contributes directly to the progeny produced. Typically, fertility traits are hard to quantify and lowly heritable so they are often ignored in breeding programs. The inclusion of male fertility traits could allow for selection on heritable traits that are easy to measure and implement in a commercial breeding program. The utilization of male fertility traits could improve overall fertility and production. Bull breeding soundness evaluation traits were heritable, ranging from low to high, allowing for genetic improvement in those traits. Seven traits were recommended as selection criteria in a breeding program, which included two physical traits and five sperm traits. Implementing these seven traits in a breeding program would allow for a higher calving rate and associated increased profits.


Asunto(s)
Análisis de Semen , Semen , Bovinos/genética , Masculino , Animales , Femenino , Análisis de Semen/veterinaria , Fenotipo , Fertilidad/genética , Reproducción
2.
Theriogenology ; 202: 103-109, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36933284

RESUMEN

This study extends observations on the effects of intra-vaginal progesterone treatment on the relationships between the time of luteolysis, emergence of the ovulatory follicle, timing of estrus and ewe fertility. Observations were made in progesterone - treated ewes in autumn, the spring equinox and late spring (Experiment 1, Data set 1) and in progesterone - treated ewes and naturally cycling ewes in autumn and the spring equinox (Experiment 1, Data set 2). In Data set 1, the day of emergence of both the first and second ovulatory follicle was positively related to the day luteal regression within each season. In turn, the day of emergence influenced the timing of estrus by means of a season by day of luteal regression interaction (P < 0.001) indicating that the relationship was positive in autumn and the spring equinox but negative in late spring. In autumn, older ovulatory follicles were associated with an earlier onset of estrus compared with younger ovulatory follicles. In late spring, this relationship was reversed and was influenced by whether or not ewes were cycling at the time of pessary insertion. In Data set 2, the relationship between the day of follicle emergence and luteal regression was influenced by a treatment by day of regression interaction indicating the relationship was positive in treated ewes and negative in naturally cycling ewes. Timing of estrus was positively related (P < 0.001) to both the day of luteal regression and the day of follicle emergence (P < 0.05), with both relationships being stronger in naturally cycling ewes than in treated ewes. In Experiment 2, pregnancy rate following artificial insemination in autumn was highest (90.2%) when luteolysis occurred during Days 7-9 of the pessary period compared with Days 1-6 (77.8%, P = 0.16), 10 to 12 (68.8%, P < 0.05) or Days ≥13 (71.2%, P < 0.05). Timing of estrus was not affected. The mean diameter of ovulatory follicles that emerged during Days 7-9 was larger on Day 12 (5.8 ± 0.13 mm) compared with other periods (range 4.7 ± 0.05 to 5.6 ± 0.14 mm). This study provides two potential strategies to improve the success of AI programs. Firstly, appropriately timed treatment with PGF2α to control the time of emergence of ovulatory follicles and, secondly, earlier treatment with eCG to improve the development of ovulatory follicles that emerge late in the pessary period. Each is likely to be influenced by season and the cyclical status of the ewe.


Asunto(s)
Inseminación Artificial , Folículo Ovárico , Progesterona , Ovinos , Femenino , Animales , Folículo Ovárico/fisiología , Progesterona/farmacología , Pesarios/veterinaria , Estro , Reproducción , Inseminación Artificial/veterinaria , Modelos Lineales , Estaciones del Año , Resultado del Embarazo/veterinaria , Embarazo , Factores de Tiempo
3.
Animals (Basel) ; 12(21)2022 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-36359041

RESUMEN

Media portrayals of animal cruelty can shape public understanding and perception of animal welfare law. Given that animal welfare law in Australia is guided partially by 'community expectations', the media might indirectly be influencing recent reform efforts to amend maximum penalties in Australia, through guiding and shaping public opinion. This paper reports on Australian news articles which refer to penalties for animal cruelty published between 1 June 2019 and 1 December 2019. Using the electronic database Newsbank, a total of 71 news articles were included for thematic analysis. Three contrasting themes were identified: (1) laws are not good enough; (2) laws are improving; and (3) reforms are unnecessary. We propose a penalty reform cycle to represent the relationship between themes one and two, and 'community expectations'. The cycle is as follows: media reports on recent amendments imply that 'laws are improving' (theme two). Due to a range of inherent factors in the criminal justice system, harsher sentences are not handed down by the courts, resulting in media report of 'lenient sentencing' (theme one). Hence, the public become displeased with the penal system, forming the 'community expectations', which then fuel future reform efforts. Thus, the cycle continues.

4.
Animals (Basel) ; 11(7)2021 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-34359180

RESUMEN

The ability to assess the welfare of animals is dependent on our ability to accurately determine their emotional (affective) state, with particular emphasis being placed on the identification of positive emotions. The challenge remains that current physiological and behavioral indices are either unable to distinguish between positive and negative emotional states, or they are simply not suitable for a production environment. Therefore, the development of novel measures of animal emotion is a necessity. Here we investigated the efficacy of microRNA (miRNA) in the brain and blood as biomarkers of emotional state in the pig. Female Large White × Landrace pigs (n = 24) were selected at weaning and trained to perform a judgment bias test (JBT), before being exposed for 5 weeks to either enriched (n = 12) or barren housing (n = 12) conditions. Pigs were tested on the JBT once prior to treatment, and immediately following treatment. MiRNA and neurotransmitters were analyzed in blood and brain tissue after euthanasia. Treatment had no effect on the outcomes of the JBT. There was also no effect of treatment on miRNA expression in blood or the brain (FDR p > 0.05). However, pigs exposed to enriched housing had elevated dopamine within the striatum compared to pigs in barren housing (p = 0.02). The results imply that either (a) miRNAs are not likely to be valid biomarkers of a positive affective state, at least under the type of conditions employed in this study, or (b) that the study design used to modify affective state was not able to create differential affective states, and therefore establish the validity of miRNA as biomarkers.

5.
Animals (Basel) ; 12(1)2021 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-35011167

RESUMEN

Multiple studies have quantified the production differences of Hereford Angus crossbreds compared to purebred Angus for a range of traits including growth, carcass, and reproductive traits. This study aims to quantify breed and heterosis effects on maternal performance using genomics. Thirty Hereford and thirty Angus sires were mated to 1100 Angus heifers and cows in a large commercial herd run on pasture at Musselroe Bay, Tasmania, Australia. Approximately 1650 calves were born. Heifers were weaned, scanned for attainment of puberty prior to joining at approximately 15 months of age, joined, and then recorded for status of pregnancy, calving, lactating, 2nd pregnancy, and weaning of second calf. Heterozygosity effects were significant for heifer pre-joining weight and height as well as proportion pubertal. Breed differences were significant for the same traits plus pregnancy rate at second joining and proportion rearing two calves. Genetic parameters were reported for 13 traits. On average, higher genetic merit (Estimated Breeding Value, EBV percentile) Hereford bulls were used than Angus for growth and puberty, but they were similar for fat and reproduction. Days to calving BREEDPLAN EBVs of the sires were related to puberty and reproduction. Scrotal size BREEDPLAN EBVs of the sires were related to attainment of puberty genomic EBVs calculated. In summary, breed differences in growth and puberty were due to heterosis, but there was an advantage of Hereford genes for reproductive performance. Ongoing emphasis on selection for reduced days to calving and estimation of multi-breed EBVs is important.

6.
Animals (Basel) ; 11(1)2020 Dec 26.
Artículo en Inglés | MEDLINE | ID: mdl-33375377

RESUMEN

Animal welfare is not included in the Australian Constitution, rendering it a residual power of the states and territories. Commentators have suggested that inconsistencies exist between the state and territory statutes, and that a uniform approach would be beneficial. However, there has been no comprehensive assessment of the nature or extent of these purported inconsistencies. This review addresses this gap by providing a state-by-state comparison of animal protection statutes based on key provisions. Utilizing systematic review methodology, every current Australian statute with an enforceable protection provision relating to animal welfare was identified. A total of 436 statutes were examined, with 42 statutes being included in the detailed analysis. The comparison showed that animal protection laws are generally consistent between each Australian jurisdiction and were found to have similar shortcomings, notably including lack of a consistent definition of 'animal' and reliance on forms of legal punishment to promote animal welfare which have questionable effectiveness. It is argued that there is a need for attention to definitions of key terms and future consideration of alternative forms of penalties, but that a uniform federal approach may not be necessary to address these shortcomings.

7.
Animals (Basel) ; 10(3)2020 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-32183062

RESUMEN

Previous research has identified a number of issues arising at all stages of the animal law enforcement process. These issues contribute to an enforcement gap between the written law, as it relates to the penalties laid out in statutes, and the reality of the animal law justice system. This paper identifies and investigates the contributors to this gap. The identified factors discussed are (1) the role of the public in reporting animal cruelty, (2) the ambiguity of the language used in animal welfare legislation, (3) the nature of enforcement authorities, and (4) the role of the courts. Thus, the causes of the enforcement gap are multifactorial, derived from all stages of the enforcement process. Further research on the enforcement model and public education, in addition to debate on legislative reforms, will be needed to address this gap.

8.
PLoS One ; 15(1): e0228413, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31986185

RESUMEN

Behavioural indicators of affective state, including burrowing, clinical scores and the Mouse Grimace Score have not yet been validated in mouse models of chronic gastrointestinal disease. Additionally, a comparison of these methods has not been characterised. This study aimed to determine which behavioural assessment was the optimal indicator of disease, evidenced by correlation with clinically-assessed measures, in an azoxymethane (AOM)/dextran sulphate sodium (DSS) mouse model of colitis-associated colorectal cancer. C57BL/6 mice were allocated to four groups (n = 10/group); 1) saline control, 2) saline+buprenorphine, 3) AOM+DSS+water, 4) AOM+DSS+buprenorphine. Mice were gavaged thrice weekly with water or buprenorphine (0.5mg/kg; 80µL) for 9 weeks. Disease activity index (DAI) was measured daily; burrowing and grimace analyses occurred on days -1, 5, 19, 26, 40, 47 and 61. Colonoscopies were performed on days 20, 41 and 62. All animals were euthanized on day 63. Burrowing activity and retrospective grimace analyses were unaffected (P>0.05), whilst DAI was significantly increased (P<0.05) in mice with colitis-associated colorectal cancer compared to normal controls. In addition, DAI was positively correlated with colonoscopically-assessed severity and tumour number (P<0.05). We conclude that traditional measures of DAI or clinical scoring provide the most reliable assessment of wellbeing in mice with colitis-associated colorectal cancer.


Asunto(s)
Azoximetano/efectos adversos , Buprenorfina/administración & dosificación , Colitis/complicaciones , Neoplasias Colorrectales/complicaciones , Sulfato de Dextran/efectos adversos , Dimensión del Dolor/métodos , Animales , Conducta , Colitis/inducido químicamente , Colonoscopía , Neoplasias Colorrectales/etiología , Neoplasias Colorrectales/psicología , Modelos Animales de Enfermedad , Ratones , Ratones Endogámicos C57BL , Estudios Retrospectivos , Medición de Riesgo
9.
Prev Vet Med ; 170: 104714, 2019 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-31421492

RESUMEN

Although dogs routinely travel in motor vehicles, there is a lack of evidence on if, how, and why people choose to restrain their dogs when travelling. A lack of restraint is likely to be associated with an increased risk of serious injury or death in the case of an accident, and in some cases may even precipitate an accident. The aim of the present study was to determine the frequency in which dog restraints are used in the US, UK and Australia in a convenience sample, and the factors associated with whether or not a dog is restrained. Online surveys using SurveyMonkey® were distributed in the US, UK and Australia during 2017-2018. The survey consisted of questions related to owning a dog, owner and dog demographics, use of restraint when driving with the dog, reasons for restraining/not restraining the dog, and attitudes to restraint of dogs in vehicles. A logistic regression was used to determine factors associated with the use of restraint. There were 706, 692 and 637 completed surveys from the US, UK and Australia, respectively. A little over half of respondents restrained their dog in the US (55%) compared to 67% in Australia and 72% in the UK. The most common method of restraint in the US and UK was a cage/crate in the cargo area in the back of the vehicle; in Australia it was a harness and tether attached to a seat buckle. In the generalised linear model, country, dog size, owner age, dog age and vehicle type were all significant factors associated with the use of restraint for dogs in cars. Younger dog owners from the US who drove a pickup truck or utility van, had a large dog, and drove with their dogs less frequently were least likely to restrain their dogs. This research highlights the need for improved education and information regarding the use of restraints for dogs traveling in vehicles, although the limitations in the convenience sample used mean further research is needed, including use of a more representative sample.


Asunto(s)
Perros , Vehículos a Motor/normas , Equipos de Seguridad/estadística & datos numéricos , Adulto , Anciano , Animales , Australia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Vehículos a Motor/clasificación , Reino Unido , Estados Unidos , Adulto Joven
10.
Animals (Basel) ; 8(12)2018 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-30544781

RESUMEN

Animal welfare legislation in South Australia underwent amendments in 2008, where all the maximum penalties for animal welfare offences were doubled. This commitment to increased penalties arguably provides evidence of the legislature's intent with respect to penalties. Studies have speculated that the legislative intent behind the increased penalties is not being reflected in the courts. This interdisciplinary research sought to gain evidence to confirm or disprove these speculations, by quantifying the average custodial sentence and monetary fine handed down in court before and after the 2008 amendments. Furthermore, trends relating to the species of animal affected and the demographics of the offender were identified. A total of 314 RSPCA (SA) closed case files from 2006 to 2018 were converted into an electronic form. Since the amendments, the average penalties have doubled in magnitude; fines have increased from $700 to $1535, while prison sentences have increased from 37 days to 77 days. Cases of companion animal abuse were most common (75% of all cases) and the location of the offence was found to influence offending. These findings suggest that the 2008 amendments have caused the average penalties to increase. However, it is debatable whether these increases are enough to effectively punish animal abusers.

11.
J Anim Sci ; 96(9): 3856-3862, 2018 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-30060191

RESUMEN

Anogenital distance (AGD) has been used to reflect masculinization in litter-bearing species. As masculinization affects behavior and reproduction, AGD could be measured to assist in selecting gilts with a temperament more suited to commercial production and greater reproductive potential. We hypothesized that gilts from a male-biased litter would have a longer AGD and poorer reproductive performance. In Exp. 1, AGD and weight were measured at day 1, day 21, and week 16 of age for gilts from male-biased litters (≥60% males; n = 51) and female-biased litters (≥60% females; n = 51). Sow AGD was measured 3 d after farrowing. In Exp. 2, AGD was measured at gilt selection at approximately 24 wk of age and gilts followed to second parity. Litter sex ratio affected AGD at 16 wk of age, with gilts from female-biased litters having longer AGD (mean ± SEM, 9.1 ± 0.7 mm vs. 11.0 ± 0.6 mm, P = 0.013). Anogenital distance was not different on day 1 or day 21. There was no effect of sex ratio on weight at any time, and sow AGD was not associated with the sex ratio of her litter. Gilts with an AGD longer than the mean of 11.55 mm were heavier (mean ± SEM, 118.8 ± 0.4 kg vs. 117.7 ± 0.4 kg, P = 0.023), were achieved puberty earlier (179.6 ± 0.6d vs. 182.2 ± 0.6 d, P = 0.001), were mated younger (200.6 ± 0.6 d vs. 203.2 ± 0.6 d, P = 0.001), and were more likely to be mated (91% vs. 83%, P = 0.005) than gilts with an AGD shorter than the mean. Gilts with an AGD greater than 11.55 mm had a greater born alive litter size (11.79 ± 0.20 vs. 11.20 ± 0.19, P = 0.018) compared with gilts with an AGD shorter than 11.55 mm. At 16 wk, AGD was associated with sex bias and could be used as a selection tool to predict reproductive success of the first parity, with a longer AGD being associated with gilts that had been born into a female-biased litter and that had better reproductive performance.


Asunto(s)
Reproducción , Razón de Masculinidad , Porcinos/fisiología , Animales , Peso Corporal , Femenino , Tamaño de la Camada , Masculino , Paridad , Embarazo , Maduración Sexual , Porcinos/anatomía & histología
12.
Am J Physiol Endocrinol Metab ; 294(2): E425-34, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18073322

RESUMEN

Despite the well-known benefits of omega-3 (n-3) polyunsaturated fatty acid (PUFA) supplementation on human health, relatively little is known about the effect of n-3 PUFA intake on fertility. More specifically, the aim of this study was to determine how oocyte and preimplantation embryo development might be influenced by n-3 PUFA supply and to understand the possible mechanisms underlying these effects. Adult female mice were fed a control diet or a diet relatively high in the long-chain n-3 PUFAs for 4 wk, and ovulated oocytes or zygotes were collected after gonadotropin stimulation. Oocytes were examined for mitochondrial parameters (active mitochondrial distribution, mitochondrial calcium and membrane potential) and oxidative stress, and embryo developmental ability was assessed at the blastocyst stage following 1) in vitro fertilization (IVF) or 2) culture of in vivo-derived zygotes. This study demonstrated that exposure of the oocyte during maturation in the ovary to an environment high in n-3 PUFA resulted in altered mitochondrial distribution and calcium levels and increased production of reactive oxygen species. Despite normal fertilization and development in vitro following IVF, the exposure of oocytes to an environment high in n-3 PUFA during in vivo fertilization adversely affected the morphological appearance of the embryo and decreased developmental ability to the blastocyst stage. This study suggests that high maternal dietary n-3 PUFA exposure periconception reduces normal embryo development in the mouse and is associated with perturbed mitochondrial metabolism, raising questions regarding supplementation with n-3 PUFAs during this period of time.


Asunto(s)
Desarrollo Embrionario/efectos de los fármacos , Ácidos Grasos Omega-3/farmacología , Oocitos/efectos de los fármacos , Oocitos/crecimiento & desarrollo , Animales , Antioxidantes/metabolismo , Peso Corporal , Calcio/metabolismo , Dieta , Técnicas de Cultivo de Embriones , Ácidos Grasos/análisis , Femenino , Fertilización In Vitro , Potenciales de la Membrana/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Oocitos/ultraestructura , Tamaño de los Órganos , Estrés Oxidativo/efectos de los fármacos , Embarazo , ARN/biosíntesis , ARN/aislamiento & purificación , Especies Reactivas de Oxígeno/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Cigoto/efectos de los fármacos
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