Animal Production Science
Volume 59 Number 9 2019
AN18281A review of the financial impact of production diseases in poultry production systems
The academic literature on nine important poultry production diseases contains few studies reporting financial impacts. Using data on physical disease impacts, bioeconomic models were constructed which showed that uncontrolled diseases caused major financial losses, although some effective disease controls were available. Without such secondary modelling, the academic literature does not allow financially optimal disease control decisions to be made.
AN18186The potential impact of breeding strategies to reduce methane output from beef cattle
Ruminants are major contributors, through methane, to greenhouse gas emissions from livestock. Improvements in efficiency through selection of superior animals for breeding reduces methane per unit of product sold – known as methane intensity. Directly selecting animals for lower methane would reduce emissions, but a focus on productivity is predicted to be almost as effective in improving methane intensity. However, a focus on better management and faster growth is likely to generate greater gains.
AN18177Effect of heat load and dietary protein on oxygen pulse and energy cost for locomotion in heifers
The oxygen pulse technique allows the energy cost of animals in production conditions to be obtained. However, there are few studies evaluating if oxygen pulse changes as a function of weather. Temperature and humidity have a low effect on oxygen pulse and the technique can be used in production conditions. Walking in terrain with a low slope can increase the energy cost of heifers considerably.
AN18205Uncovering the mechanism whereby dietary nicotinic acid increases the intramuscular fat content in finishing steers by RNA sequencing analysis
A higher dosage of nicotinic acid in the diet dramatically increases intramuscular fat content in finishing steers, but its mechanism is unknown. Here we show that dietary nicotinic acid upregulates the expression of the genes associated with adipocyte differentiation and adipogenesis, lipid and glucose metabolism, and fatty acid synthesis and esterification. As a feed additive, nicotinic acid can be used for the production of high-quality beef.
AN18210Metabolism of glycerol in pigs fed diets containing mixed crude glycerin and β-adrenergic agonist
Crude glycerin is an important alternative energy ingredient in the diet of pigs and the ractopamine is a feed additive that has been associated with improvements in animal performance and meat quality. The present study contributes to the advancement of the animal science, because it provides information about a subject that remains still little explored, namely, the glycerol metabolism in pigs fed diets containing glycerin and ractopamine. Such understanding is necessary to contribute to the formulation of diets that are nutritionally more adequate.
AN17758Starch sources and concentration in diet of dairy goats affected ruminal pH and fermentation, and inflammatory response
Corn is widely used in ruminants because of the low price and slow ruminal digestion rate, but wheat can sometimes be cheaper than corn. The present study evaluated the differences of lactation performance and inflammatory response between these two starch sources in different levels. The results indicate that wheat had a similar effect on lactation performance with corn, but led to more severe inflammatory responses.
AN18432Comparison of the effects of high and low milk-replacer feeding regimens on health and growth of crossbred dairy heifers
Once-a-day feeding regimens with milk replacer reduce both feed and labour costs of rearing newborn dairy heifers pre-weaning. We compared two commercial calf-feeding systems in a Spring-block (January–March) calving herd, based on milk-replacer A fed twice daily during Weeks 1–8 (High), or on milk-replacer B, for which feeding was reduced to once daily during Weeks 4–8 (Low). High group heifers showed better growth, remained larger at 6 months and had higher pre-weaning IGF1 in their circulation, a hormone indicative of metabolic health.
AN18432 Abstract | AN18432 Full Text | AN18432PDF (354 KB) | AN18432Supplementary Material (1.9 MB) Open Access Article
AN17680Effects of supplementing low-quality hay with groundnut foliage and cassava tops on feed intake, apparent digestibility and rumen fermentation in crossbred cattle
Alternative feed resources for use as protein supplements are crucial for cattle productivity in Cambodia. The present study investigated the effects of sun-dried groundnut foliage (DGF) and sun-dried cassava tops (DCT) as feed supplements to diets based on rice straw and para grass. The results indicated that both DGF and DGF + DCT improved dry-matter intake and apparent digestibility, but supplement of DCT alone reduced digestibility of protein and fibre.
AN18083Assessment of the nutritive value of urea–calcium hydroxide-treated rice straw by in sacco technique
Rice straw is a low-quality roughage source for ruminants and improving rice straw quality is very important. The objective of this study was to determine the effect of urea–lime treatment on nutritive values and rumen degradability of rice straw using the nylon-bag technique. Urea–lime-treated rice straw could improve the nutritional value of rice straw, especially 3% urea with 2% lime.
AN18063Effect of banana flower powder on rumen fermentation, synthesis of microbial protein and nutrient digestibility in swamp buffaloes
Rumen pH is important, affecting fermentation of end-products for ruminants. Banana flower powder (BAFLOP) was used as a rumen buffering agent in order to replace chemicals. Supplementation of BAFLOP resulted in higher rumen pH and volatile fatty acid, especially propionic acid.
AN18491Inclusion of yeast waste as a protein source to replace soybean meal in concentrate mixture on ruminal fermentation and gas kinetics using in vitro gas production technique
The yeast waste is by-product produced from industrial ethanol production. The aim of this study was to evaluate the effect of yeast waste powder on in vitro gas production technique. In conclusion, yeast waste could not negative effect on in vitro fermentation and digestibility, and would contribute to a reduction in environmental pollution when fed to animals.
AN17862Dietary calcium supplementation affects nutrient digestibility and antler-production performance during the antler-velvet growth period of male sika deer
This study reveals that calcium supplementation plays an important role in velvet antler growth performance. Total calcium concentration of 1.10–1.70%, on the basis of dry matter, significantly increased feed digestibility and antler daily gain for the 6-year-old sika deer. These results will contribute to increase the velvet yield.
AN17862 Abstract | AN17862 Full Text | AN17862PDF (106 KB) Open Access Article
AN16840Response of common silage corn hybrids to inoculant application: fermentation profile, carbohydrate fractions, and digestibility during ensiling
Corn silage quality is a result of silage fermentation and digestibility characteristics. Studies so far were focussed on the influence of either inoculant on fermentation characteristics, or genetically distant corn types on chemical composition and digestibility of main components. This research combines both approaches; it is a fermentation and digestibility study of diverse commercial hybrids ensiled with inoculant during storage. The study shows that even for commercial corn hybrids, when addressing silage fermentation characteristics and digestibility, a hybrid type is more relevant than inoculant.
AN18049Determination of the optimum arginine : lysine ratio in broiler diets
Arginine is an essential amino acid. Broilers cannot synthesise arginine to meet their requirements. Therefore, broilers were fed on dietary arginine for optimal growth and other functions. The optimum dietary Arg : Lys concentration was 1.05 to maximise weight gain in the grower phase (Days 11–24 of age) and carcass yield. The use of optimum Arg : Lys concentrations has enabled nutritionists to formulate cost-effective diets to improve carcass yield and performance.
AN18049 Abstract | AN18049 Full Text | AN18049PDF (117 KB) Open Access Article
AN18353Effect of dietary probiotics and stocking density on carcass traits, meat quality, microbial populations and ileal histomorphology in broilers under hot-climate conditions
The present study investigated the potential effects associated with dietary probiotic inclusion and the stocking density on carcass traits. We concluded that dietary probiotic supplementation has a positive significant effect on the ileal villus height, and significantly decreases the counts of Escherichia coli and Salmonella in the gut and litter. Moreover, colour and odour significantly improved in broilers fed a diet containing the probiotics.
AN18494Estimation of lamb deaths within 5 days of birth associated with cold weather
The present study examined the effect of cold weather on lamb deaths within 5 days of birth. A model is given to estimate the proportion of lambs expected to die for any given chill index.
AN18400Commingled black and white cows (Bos taurus; Angus and Charolais) in high-elevation rangeland are differentially parasitised by Haematobia irritans
Horn flies, an external parasite of cattle, are not well understood in high-elevation rangelands. We measured horn flies on black Angus cows and white Charolais cows in 2016 and 2017. Annual fly infestations were four times greater or more on black cows both years. Not all cattle reached economic thresholds all years. Cow colour fly preference in our environment may be explained by external temperatures of black cows. Manipulating host colour and thermal preferences of horn flies could enhance beef production.
AN18311Productivity and profitability of alternative steer growth paths resulting from accessing high-quality forage systems in the subtropics of northern Australia: a modelling approach
This study assessed the most profitable ways to incorporate high-quality forages (oats and leucaena) into whole-of-life growth paths of steers otherwise grazing buffel grass pastures in central Queensland. For both a steer turnover enterprise and a breeding and finishing enterprise the strategy of grazing steers on leucaena-grass pastures from weaning until they achieved feedlot entry weight was substantially more profitable than any of the other 21 growth paths. Incorporation of forage oats into a buffel grass growth path always reduced the profitability of beef cattle enterprises.
AN18064Performance, carcass and meat quality traits of grazing cattle with different exit velocity
Animal temperament could affect not only meat production but also quality. Though temperamental animals, i.e. more reactive ones, get used to the production system as they spend time on it, they produce carcasses with less fat cover and lower glycogen content in the muscles. These traits could increase the risk of low meat quality obtained from temperamental cattle under severe stressful situations. Additional feeding or animal management strategies should be considered for them.
AN18424Effective incorporation of xylanase and phytase in lick blocks for grazing livestock
Lick blocks are used to supplement grazing livestock and increase the nutritional value of low quality pasture and they could be improved further by the addition of enzyme supplements. High temperatures used to make lick blocks could inactivate feed enzymes. The present research however shows that active enzymes could be incorporated into lick blocks. If these results were applied in lick block manufacturing then grazing livestock could benefit from enzyme supplementation using the established and convenient lick block delivery system.