Animal Production Science
Volume 59 Number 8 2019
AN18487Towards a new phenotype for tick resistance in beef and dairy cattle: a review
About 80% of the world’s cattle are affected by ticks and tick-borne diseases, with estimated economic losses from ticks ranging from US$20 to US$30 billion per year. Cattle host resistance is the most important factor affecting the economics of tick control, but it is largely absent in tick-control programs due to the difficulties and expense of identifying host tick resistance. The present paper reviews the literature to identify factors affecting resistance of cattle to ticks, so as to develop cost-effective ways of measuring tick resistance in cattle. The review recommends that three possible methods (haemolytic analysis; skin hypersensitivity reactions; simplified artificial tick infestations) be further developed to consistently, cost-effectively and reliably measuring cattle tick resistance.
AN18487 Abstract | AN18487 Full Text | AN18487PDF (1.1 MB) Open Access Article
AN17720Strategies and cost–benefit of selecting for a polled sheep nucleus by using DNA testing
Australian Merino sheep can be bred with horns or without (polled). There is evidence suggesting polled rams are becoming more desirable due to increased welfare standards for both the individual sheep and their human handlers. As such there is indication that ram buyers will pay a premium for polled rams at present. This paper investigates breeding strategies to infuse the poll gene into a flock and the cost–benefit to the ram breeder.
AN17714Importance of genotype by environment interaction on genetic analysis of milk yield in Iranian Holstein cows using a random regression model
Genotype by environment (G × E) interaction is a potential source of milk yield in genetic improvement programs in dairy cattle. The results indicate clear evidence of strong G × E interaction that would have a significant negative affect in breeding programs and selection for milk yield.
AN18090Metabolic, follicular and embryo production responses of postpartum crossbred Holstein × Gir dairy cows fed diets with different energy levels
Crossbred Holstein × Gir (HG) cows are crucial for the Brazilian dairy industry. In this study, the aim was to evaluate the effect of two diets of differing energy levels and two genetic groups on the metabolic and hormonal profiles and on oocyte and embryo production during the early postpartum period. The high-energy diet was more efficient in maintaining the energy status and 3/4 HG cows are were more efficient at producing oocytes.
AN18102Immunohaematological status and mRNA expression of the genes encoding interleukin-6, nuclear-factor kappa B, and tumor-necrosis factor-α in the spleen of broilers supplemented with dietary rutin
Modulation of the immune response by using feed additives has been considered as one of the most important prophylactic strategies in animal production. The present study aimed to evaluate the effects of different levels of dietary rutin by measuring the mRNA expression of immune response-associated genes in spleen tissue. This study demonstrated that rutin promoted the immune strength in birds, mainly at 1 g/kg diet, suggesting that rutin is a promising feed additive for broilers.
Usually, bulls are castrated to improve meat quality, but physical castration can negatively affect animal welfare. The effects of immunisation against the gonadotropin-releasing factor depend on the stage of puberty of the animal, and the effects differed for light and heavy bulls, with a decrease in the formation of metmyoglobin in light bulls and improved meat tenderness. Immunisation is an effective technique for producing tender meat without long periods of refrigerated storage, thereby reducing the costs of production.
AN18149Portal drained-viscera heat production and net flux of volatile fatty acids in Iberian pigs fed acorn
The most expensive cured products of Iberian pigs come from animals finishing in open range and eating mainly acorns from oak trees, which is a shift from a balanced to an unbalanced diet. With time, the energy expenditure of viscera involved in the digestion process increased, but the use of the nutrient studied – volatile fatty acids – did not. Adaptation to an unbalanced diet implies adjustments in the use of nutrients by the digestive viscera.
AN18242Changes in intestinal proteins induced by colostrum uptake in neonatal calves: analysis by two-dimensional gel electrophoresis-based proteomics analysis
The uptake of colostrum by neonatal calves plays a central role in determining the success or failure of the passive transfer of immunity. The aim of this study was to investigate colostrum components internalised in the small intestine using a proteomics approach. The results of the present study show the distribution and variation of internalised IgG in the small intestine after calves received colostrum. These findings may provide the fundamental data for improvements in calf rearing and management.
AN18220Dietary crude palm oil supplementation improves egg quality and modulates tissue and yolk vitamin E concentrations of laying hen
The objective of the present study was to examine the dietary inclusion of crude palm oil (CPO) on egg quality and vitamin E distribution in the laying hen. The vitamin E tocotrienol in the CPO, especially at 40 g/kg diet, helps reduce cholesterol concentrations and improve the quality of the egg. The distribution and concentration of both forms of vitamin E (tocopherol and tocotrienol) in the liver, adipose tissues and plasma were enhanced by inclusion of CPO in the diet of laying hens.
AN18100Ethanol extract of mango seed is a suitable plant-based replacement for synthetic antioxidants in pig grower–finisher diets
Concern regarding the dietary use of synthetic antioxidants in animal production has resulted in studies with natural antioxidants. The inclusion of ethanolic mango seed extract (EECM) in growing-finishing pig diets was evaluated and greater protection against oxidative damage, in addition to benefits to animal health, was observed. Thus, EECM has the potential to replace synthetic antioxidants in pig diets.
AN17425Pasture condition and milk production by grazing dairy cows as affected by daily herbage-allowance restriction
Daily herbage allowance is the major grazing management facet of pasture-based dairy-production systems. The study evaluated the long-term effects of daily herbage allowance on pasture condition and milk production of dairy cows. The results showed that using 20 kg DM/cow.day of daily herbage allowance was appropriate to improve both herbage utilisation and milk production per hectare, without affecting long-term pasture condition.
AN16820Comparative effects of ‘solid’-fat sources as a substitute for yellow grease on digestion of diets for feedlot cattle
Generally, the term ‘sequestered’ in supplemental fats is confused with ‘inert’. The objective of the present experiment was to evaluate the comparative effects of some sequestered fat sources as a substitute for yellow grease on characteristics of digestion of growing diets for feedlot cattle. On the basis of nutrient digestion and FA digestibility, supplementation with sequestered fat did not afford advantages over yellow grease in growing diets fed to feedlot steers.
AN16008Effect of Lactobacillus plantarum and Lactobacillus buchneri addition on fermentation, bacterial community and aerobic stability in lucerne silage
Lucerne is difficult to ensile and the relationship between fermentation characteristics and bacteria community during ensiling is poorly understood. The present study evaluated the changes of fermentation characteristics, aerobic stability, and bacterial community of Lactobacillus plantarum and Lactobacillus buchneri application during lucerne ensiling, the inoculation improved quality of lucerne silage and influenced the abundances of other community members to affect the silage nutritional values. This description of the bacterial community dynamics that occurred during ensiling expands our knowledge of fermentation processes.
AN17039In vitro characterisation of two Lactobacillus strains and evaluation of their suitability as probiotics for growing-finishing pigs
Intestinal health plays an important role in promoting the healthy growth of animals. The present study showed that the two Lactobacillus strains exhibited excellent probiotic characteristics in vitro and in vivo for growing-finishing pigs. The results contribute to our understanding of the probiotic activity of the strain and its application in animal production.
Longevity is a desirable trait that affects profitability in dairy cattle. Studies associating somatic cell scores with longevity can benefit farmers and help them in selecting animals. No study in Brazil has reported association between these traits in Holstein cows using survival analysis approach. The results denote a positive effect on longevity when cows are selected to reduce somatic cell scores.
High calcium (Ca) oxalate limits the utilisation of giant taro (Alocacia macrorrhiza) corm by poultry. Feeding 200 g sun-dried whole corm meal/kg diet depresses performance of laying hens. Peeling the corm or increasing inorganic Ca level overcomes the deleterious effect of Ca oxalate and improves laying performance. These findings can be used to reduce feed cost where giant taro is readily available.
AN17743Estimation and mitigation of GHG emissions from ruminant livestock in Pakistan
Livestock farming, a backbone of economy in developing countries, is a major source of greenhouse-gas emissions and highly exposed to the impact of climate change. This makes the livestock sector a prime target for mitigation efforts. Country-specific national adaptation planning is crucial to build climate resilience for food security and requires establishing baseline data and exploring mitigation potentials of greenhouse-gas emissions from livestock. The current study is an effort towards this end, for generating emission data and exploring interventions to reduce the intensity for supporting climate-smart livestock production in Pakistan.
AN17481The traditional livestock breeding practices of women and men Somali pastoralists: breeding management and beliefs on breeding issues
Livestock are the mainstay of the economy in Somalia, one of the world’s poorest countries. Here we document the breeding practices of women and men Somali pastoralists, for the main livestock species kept (goat, sheep, camel and cattle). Overall the pastoralists were found to employ sound breeding practices, although there is room for capacity building such as on inbreeding.
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