ABSTRACT. Predictive ability of genomic EBV when using single-step genomic BLUP (ssGBLUP) in Angus cattle was investigated. Over 6 million records were available on birth weight (BiW) and weaning weight (WW), almost 3.4 million on postweaning gain (PWG), and over 1.3 million on calving ease (CE). Genomic information was available on, at most, 51,883 animals, which included high and low EBV accuracy animals.

ABSTRACT Quality control filtering of single-nucleotide polymorphisms (SNPs) is a key step when analyzing genomic data. Here we present a practical method to identify low-quality SNPs, meaning markers whose genotypes are wrongly assigned for a large proportion of individuals, by estimating the heritability of gene content at each marker, where gene content is the number of copies of a particular reference allele in a genotype of an animal (0, 1, or 2). If there is no mutation at the marker, gene content has an additive heritability of 1 by construction.

ABSTRACT. One of the main animal health problems in tropical and subtropical cattle production is the bovine tick, which causes decreased performance, hide devaluation, increased production costs with acaricide treatments, and transmission of infectious diseases. This study investigated the utility of genomic prediction as a tool to select Braford (BO) and Hereford (HH) cattle resistant to ticks.

ABSTRACT. Performance of nymphs and adults of Piezodorus guildinii (Westwood) feeding on different cultivated legumes was studied under controlled laboratory conditions (25 ± 1°C, 80 ± 10% RH, 14 h of photophase) on soybean immature pod (SIP; R5.5?R6), birdsfoot trefoil immature pod (BTIP), alfalfa immature pod (AIP), and red clover flower with immature seeds (RCF). Food had significant effects on the life history of P. guildinii.

ABSTRACT. Performance of nymphs and adults of Piezodorus guildinii (Westwood) feeding on different cultivated legumes was studied under controlled laboratory conditions (25 ± 1°C, 80 ± 10% RH, 14 h of photophase) on soybean immature pod (SIP; R5.5?R6), birdsfoot trefoil immature pod (BTIP), alfalfa immature pod (AIP), and red clover flower with immature seeds (RCF). Food had significant effects on the life history of P. guildinii.

ABSTRACT. This article analyzed the weight of land in the economic performance of the primary livestock production sector, using the policy analysis matrix (PAM). The financial cost of the assets immobilized with the land factor was considered through its opportunity cost (OC).

The aim of this experiment was to evaluate the utility of CO2 production rate (CPR; g CO2/d) and animal weight (WT) data as proxies for feed-intake to adjust methane production rate (MPR; g CH4/d) in situations where dry-matter intake (DMI) is not known. This experiment measured individual-animal DMI, MPR and CPR in the feedlot, and then again on restricted quantities of grain and roughage diets in open-circuit respiration chambers. Of the 59 cattle tested in the feedlot, 41 had MPR and CPR recorded, and 59 and 57 had test results on the restricted grain and roughage rations.

Spot measurements of methane emission rate (n = 18 700) by 24 Angus steers fed mixed rations from GrowSafe feeders were made over 3- to 6-min periods by a reenFeed emission monitoring (GEM) unit. The data were analysed to estimate daily methane production (DMP; g/day) and derived methane yield (MY; g/kg dry matter intake (DMI)). A one-compartment dose model of spot emission rate v. time since the preceding meal was compared with the models of Wood (1967) and Dijkstra et al. (1997) and the average of spot measures. Fitted values for DMP were calculated from the area under the curves.

Methods to measure enteric methane (CH4) emissions from individual ruminants in their production environment are required to validate emission inventories and verify mitigation claims. Estimates of daily methane production (DMP) based on consolidated short-term emission measurements are developing, but method verification is required. Two cattle experiments were undertaken to test the hypothesis that DMP estimated by averaging multiple short-term breath measures of methane emission rate did not differ from DMP measured in respiration chambers (RC).

ABSTRACT. The flight distance from humans and the reaction of the mother to human handling of their offspring are measures that can be used to assess the quality of the human-animal relationship which could vary according to animals? position in a group. The objective was to determine if the flight distance and the mother?s reaction to human handling of her fawn during the first 24 h after birth differ according to pampas deer (Ozotoceros bezoarticus) hinds? social rank. A complementary aim was to compare the mothers? reaction to their fawns being handled relative to its sex.