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Publications

NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.

2023

Abstract

LoRa-WAN sensors were used to compare methods for determining walking distances by grazing cattle in near real-time. The accuracy of relying on a global positioning system (GPS) alone or in combination with motion data derived from triaxial accelerometers was compared using stationary control trackers (Control) placed in fixed field locations (n=6) or vs. trackers (Animal) mounted on cows (n=6) grazing on pasture at the New Mexico State University’s Clayton Livestock Research Center. Trackers communicated motion data at 1-minute intervals and GPS positions at 15-minute intervals for seven days. Daily distance walked was determined using: 1) raw GPS data (RawDist), 2) data with erroneous GPS locations removed (CorrectedDist), or 3) data with erroneous GPS locations removed and with GPS data associated with the static state excluded (CorrectedDist_Act). Distances were analyzed via one-way ANOVA to compare Control vs. Animal deployment effects. No difference (P=0.43) in walking distance was detected between Control vs. Animal for RawDist. However, distances calculated for CorrectedDist differed (P<0.01) between the two tracker deployments. Due to the random error of GPS measurements, CorrectedDist for stationary devices differed (P=0.01) from zero. The walking distance calculated by CorrectedDist_Act differed (P<0.01) between Control vs. Animal trackers, with distances for Control trackers not differing (P=0.44) from zero. The fusion of GPS and accelerometer data was a more suitable method for calculating walking distance by grazing cattle. This result may highlight the value of combining more than one source of independent sensor data in Precision Livestock Farming applications.

Abstract

Virtual fencing (VF) is an alternative method to control livestock dispersal. This method consists of the use of animal wearable collars that employ auditory-electric pulse cues to deter animals from exiting their predefined containment zones. The study aimed to document skin defense (SkinM) and association learning mechanism (AssocM) in describing the conditioning behavior of the VF application. Nursing Brangus cows at the New Mexico State University’s Chihuahuan Desert Rangeland Research Center were allotted three days of free access to feeding areas (0.19ha) with VF-deactivated (VF-Off) or VF-Activated (VF-On) collars restricting one-third of the penned area. This training sequence was repeated twice (6-day/Period) with two replications (n=11 and 17cows). The VF collars communicated real-time animal positions at 15-minute intervals. ANOVA was used to compare daily-derived variables per cattle on the percentage of time spent within the containment and restricted zones (SkinM) and the number of auditory and electric pulses emitted during the VF-On configurations (AssocM). The VF-On treatment increased the percentage of time collared animals spent within the containment zone (98.4 vs.72.0 ±1.0 %Time;P<0.01) and reduced the percentage of time within the restricted zone (1.6 vs.28.0 ±1.0 %Time;P<0.01) compared to the VF-Off treatment. Exposure to VF-On in Period 1 triggered a greater frequency of auditory (1.8 vs.0.6 ±0.4;P<0.01) and electrical pulses (0.7 vs.0.2 ±0.2;P<0.01) than in Period 2. Results indicate that groups of cows learn rapidly to respond to VF boundaries by reducing the time spent within the restricted areas (SkinM) and relying increasingly on auditory cues to alter behavior (AssocM).

To document

Abstract

A continuous production experiment was conducted in Norway with 48 Norwegian Red dairy cows in early- to mid-lactation, to investigate the effect of grass silage with lactic acid bacteria (LAB) or formic acid (FA) additives, on milk yield (MY) and milk protein yield (MPY). Grass wilted to 250 g dry matter (DM)/kg was inoculated with homofermentative LAB to obtain LAB silage, whilst FA silage was produced adding a FA-based additive. The two silages were fed ad libitum and supplemented with an average 10.3 kg of either high (H) or low (L) metabolizable protein (MP) concentrates, in a 2 ✗ 2 factorial arrangement of treatments. The treatments were LAB silage and L concentrate, LAB silage and H concentrate, FA silage and L concentrate and FA silage and H concentrate. The use of FA resulted in lower levels of residual water-soluble carbohydrates (WSC), and higher levels of ammonia nitrogen (NH3single bondN), compared to LAB. In situ results for FA silage showed lower rumen degradability of crude protein (CP), while gas in vitro results showed lower utilizable CP (uCP), compared to LAB silage (782 vs. 750 g/kg DM and 128 vs. 119 g/kg DM, respectively). The purine over creatinine (PDC) index did not indicate any effects on the microbial protein synthesis (MPS) from any of the treatments. The higher daily intake of FA silage (12.5 vs.13.7 kg DM for LAB and FA, respectively, P < 0.001), did not result in significant differences in daily MY (31.0 vs. 30.2 kg, P = 0.208), nor MPY (1.08 vs.1.07 kg/day, P = 0.878) for LAB and FA, respectively. Feeding H concentrate gave higher MPY (P = 0.036), higher urea in milk (P < 0.001), plasma (P < 0.001) and urine (P = 0.008) and tended to give higher MY (P = 0.063) for both silages. For amino acids (AA) in plasma, alanine was higher for FA silage than for LAB silage (P = 0.030), while histidine (P = 0.001), leucine (P = 0.015) and glutamine (P = 0.007) were higher for both silages when cows were fed H concentrate. In conclusion, the FA and LAB additives did not affect MY or MPY any differently. Feeding H concentrate resulted in higher MPY for both silages, but reduced nitrogen (N) efficiency.