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Animal Production Science
Volume 58 Number 9 2018
AN17192The sex ratio of a gilt’s birth litter can affect her fitness as a breeding female
The breeding capacity of female pigs may be affected by male littermates in utero. This literature review covers the known effects of masculinisation of female rodents and sheep, as well as the knowledge gaps in pigs. The findings suggest that the effect of the birth litter sex ratio of a gilt on her suitability for breeding should be investigated further.
AN16712Meta-analysis of genetic-parameter estimates for reproduction, growth and carcass traits in Nellore cattle by using a random-effects model
Different studies have reported contradictory heritability and genetic-correlation estimates for reproduction, growth and carcass traits in purebred Nellore cattle. The motivation for the present study was to remove the heterogeneity between published estimates and summarise the results through meta-analysis using a random-effects model.
AN16548Genetic evaluation of bodyweight, scrotal circumference, and visual appraisal scores in Bos indicus cattle
Estimates of genetic parameters are broadly studied in Brazil for Bos indicus animals, particularly in Nellore cattle, but conversely, for Guzerat, another B. indicus breed, no studies were performed. A study was designed to estimate the genetic parameters and trends for body conformation measures. The magnitude of direct heritability estimates ranged from moderate to high, and genetic and phenotypic trends indicate favourable changes during the evaluated period.
AN16570Determining the appropriate selection index for Rayeni Cashmere goat under pasture-based production system
Rayeni Cashmere goat is raised by nomads in Kerman province of Iran. Nomads have no guidelines to establish a breeding program in their herds. The aim of the current study was to investigate breeding goals and find the best selection index for Rayeni Cashmere goat. The most appropriate selection index for this breed was determined to improve nomad income by genetic improvement of Rayeni Cashmere goat epopulations.
AN16162The effect of nitrate supplementation on arterial blood gases, haemoglobin fractions and heart rate in Bos indicus cattle after exercise
Nitrate salts are recommended to reduce methane emissions in extensively grazed cattle. After treatment with nitrate salts for 7 days and walking 3 km Bos indicus steers demonstrated a reduction in the oxygen carrying capacity of their blood and an elevated heart rate. The recommended dose rate of nitrate salts to reduce methane emissions in cattle will create a hypoxaemia in cattle.
AN16801Sperm quality, and morphology and apoptosis of germinal epithelium cells of ram lambs receiving water of different salinities
The ground water from semiarid areas has been an alternative source of drinking water for the small ruminants; however, it shows a wide variation in the concentration of total dissolved solids (i.e. salinity). Consequently, water salinity could affect apoptosis in testicular seminiferous tubules and, further, semen quality in ovine species, which was confirmed in the present study. Therefore, high-salinity water should be avoided because it increases the damage to the germinal cells of ram lambs.
AN16601Effect of herbage allowance on productive and reproductive responses of primiparous beef cows grazing on Campos grassland
The Campos region is the largest biogeographic unit of native grasslands in South America and cow-calf operations primarily graze this grassland. We studied the effects of herbage allowances of 2.5 (low) and 4 (high) kg dry matter/kg liveweight in primiparous beef cows over the entire production cycle on forage mass, cow body condition score, cow liveweight, stocking rate, postpartum anoestrus, probability of pregnancy and calf weight at weaning. The forage mass, reproductive and productive responses were improved in high herbage allowances over 2 years with different patterns of rainfall.
AN16687Influence of low-protein and low-amino acid diets with different sources of protease on performance, carcasses and nitrogen retention of broiler chickens
There are some nutritional strategies that can be used to improve poultry performance and public health like supplementation of commercial enzymes to low-protein diets. The aims of this study were to evaluate the impacts of commercial enzymes supplemented into low-protein diets on performance and economic aspects of broilers. Using different commercial enzymes in low-density diets can partially improve performance and economic aspects in broilers.
AN16290Effect of biochar, zeolite and bentonite feed supplements on egg yield and excreta attributes
Low rates of feed additive can improve poultry production and excreta characteristics. Biochar, zeolite and bentonite added to layer poultry rations at low rates resulted in improved feed conversion rates, especially when birds were challenged with fungus contaminated feed. These results may reflect an impact of these feed amendments on gut ‘health’ (microbiology or absorption of feed toxins).
AN16838Social rank and reproductive performance in a herd of farmed red deer females (Cervus elaphus)
Hierarchical relationships between individuals of several ruminant species result in differential access to resources and thus in advantages in reproductive performance of those of higher social rank. Under captive conditions with high food availability as in the present experiment, reproductive traits of red deer females were unrelated to social rank. These results reaffirm the concept that most ruminants have plastic responses to environmental conditions, and thus, not necessarily social structure affects their reproductive performance.
AN16438Offsets required to reduce the carbon balance of sheep and beef farms through carbon sequestration in trees and soils
This study demonstrates that sheep and beef enterprises can reduce or entirely offset their greenhouse gas emissions by storing carbon in trees. The carbon balance was calculated for enterprises with different stocking rates and levels of tree cover, and an intensively stocked case study farm was also analysed. Most stocking rates were carbon positive with >20% tree cover. This study provides an important reference point for farmers, researchers and policy analysts to estimate the carbon balance of farms.
AN16440Quantifying dairy farm nutrient fluxes and balances for improved assessment of environmental performance
Excess nutrients are challenging the long-term sustainability of grazing-based dairy farming. We have developed an online tool that quantifies nutrient fluxes, balances and efficiency, as well as feed and milk production performance at the whole-farm level. This standardised assessment provides dairy farmers, advisors and industry and policy analysts with the ability to improve environmental performance and develop industry-wide goals.
AN16437Endoparasite and nutritional status of Suffolk lambs in seven production systems
Endoparasite and nutritional statuses of Suffolk lambs were compared across a range of production systems in subtropical conditions of Brazil. The weaned-feedlot lambs and those in the controlled-suckling systems presented the best performance, and the animals in creep-feeding and creep-grazing had the best overall performance on pasture. Production systems exert a major influence on lamb performance, mainly when the ewe is present and supplementation is given on pasture. Nutritional status in different production systems may support overcoming the challenge caused by gastrointestinal nematodes.
AN16012Improving forage nutritive value and botanical composition in a natural grassland using different grazing methods and herbage allowances
The management of natural grasslands is crucial to increase meat production and ranchers profitability. This study aimed at assessing winter management of natural grasslands using sheep; continuous stocking and 12% herbage allowance improved sward quality in spring. These results provide an important management tool for grasslands ranchers so as to improve sward quality during spring.
AN16308Comparison of bacterial populations in bedding material, on teat ends, and in milk of cows housed in compost bedded pack barns
The management of compost bedded systems aims to provide a clean and comfortable place for cows. However, unappropriated management can increase bedding moisture, which may reflect on cow’s health and milk quality. This study proposed to understand the relationship between bacterial populations on bedding pack and bacterial population found on teat end surface and in milk. In the end, we concluded that hygiene score was not an efficient tool to estimate bacterial population on teat end and milk.
AN15873Determinants of consumer willingness to pay for quality-graded Australian sheep meat
The present study investigated the influence of a quality-grading system, demographic information and consumption preferences on consumer willingness to pay (WTP) for sheep meat. Eating quality was defined by four grades developed by the Meat Standards Australia (MSA) sheep-meat grading scheme. Results clearly showed that consumers were willing to pay more for sheep meat as eating quality improved. Robust results for the impact of demographic and consumption preferences on WTP were limited to consumer age, occupation, income level and the interaction between MSA grade and consumer age.
AN15306Consumer acceptability of beef from two sexes supplemented with essential oil mix
Essential oils have many possibilities as feed additives in livestock as natural alternatives to replace other chemical additives. Consumer acceptability of meat from these types of natural additives is important in order to increase the knowledge about these promising feeding systems. Essential oil additives in the diet of crossbred beef cattle did not negatively affect consumer meat acceptability scores or product perception.
AN16161The use of energy-protein supplement increases performance of high-yielding dairy cows and improves health-promoting properties of milk
We can increase the content of milk components desirable from the human health point of view by feeding lipid additives to cows. The aim of the study was to determine the effects of a special supplement on health-promoting properties of milk. We discovered that the supplement had a beneficial effect on milk properties, and produced milk that may serve the role of functional food for people in the future.
AN16352Effects of olive-cake supplementation on fatty acid composition, antioxidant status and lipid and meat-colour stability of Barbarine lambs reared on improved rangeland plus concentrates or indoors with oat hay plus concentrates
Medicago arborea and olive cake can be used in sheep diets as alternative feeds to reduce cost production and/or improve meat quality. Effects of olive-cake supplementation on meat quality of indoor and grazing lambs were studied. Grazing on rangeland containing Medicago arborea improved nutritional meat quality and stability of lipids. Olive cake supplementation did not have any effects.
AN16523Effects of aging on characteristics of breast meat from free-range broiler hens at 12 or 70 weeks of age
Little is known about the acceptability of free-range broiler hen meat. This study evaluated the effect of broiler age and the aging process on the properties of broiler hen breast meat. Its use is beneficial because it has lower storage and cooking losses and lower polyunsaturated fatty acid concentration, which makes it less vulnerable to rancidification. Aging for at least 3 days at 2°C is satisfactory to tenderise the breast meat from free-range broiler hens.
AN16616Using ultrasound to derive new reproductive traits in tropical beef breeds: implications for genetic evaluation
Ultrasound has enabled the identification of heifers genetically superior for the ability to reach sexual maturity and become pregnant earlier in the breeding season, attributes that profoundly impact lifetime reproduction. Research methods to identify superior individuals have laboriously involved multiple ultrasound examinations, so the current research adopted previous methodology to enable identification of superior breeding females using a single ultrasound examination. Adoption of ultrasound technology by commercial beef producers to measure fertility in their herds will be enhanced if a simple, robust system is presented.
AN16694Using Walk-over-Weighing technology for parturition date determination in beef cattle
Genetic selection can greatly increase fertility, which is a major profit driver in northern Australian beef enterprises, but to do so a cow’s calving date is required. Traditionally the calving date is recorded using laborious and costly methods, however, results show that the date can be automatically recorded using a remote weighing system. This will enable seedstock producers to more easily record the calving date, therefore, increasing the recording of fertility traits and consequently increasing the profitability of beef producers in northern Australia.
AN16694 Abstract | AN16694 Full Text | AN16694PDF (491 KB) Open Access Article
AN16097Fitting of pH conditions for the study of concentrate feeds fermentation by the in vitro gas-production technique
Estimation of microbial fermentation of concentrate feeds for ruminants from the in vitro gas-production technique is biased by the differences in incubation pH, established at ~6.5 when rumen pH actually drops below 6.0 in this type of diets. Adjustment of incubation pH by reducing the buffering of the medium is a simple way to overcome this problem in short-length incubations.
AN16577Simple and robust algorithms to estimate liveweight in African smallholder cattle
Liveweight (LW) is a key measurement for livestock owners but most farmers in sub-Saharan Africa have to use heart girth measurements to estimate LW because they cannot access scales. Most equations used to estimate LW are population specific and have large prediction errors, but using several large databases we developed an equation with less error, which can be used in a wider population. A stronger, widely applicable equation to estimate LW of African cattle will enable farmers to make better livestock management decisions.
AN16577 Abstract | AN16577 Full Text | AN16577PDF (507 KB) Open Access Article