Comparative Analysis of Milking and Behavior Characteristics of Multiparous and Primiparous Cows in Robotic Systems.

Robotic milking systems are successful innovations in the development of dairy cattle. The objective of this study was to analyse the milking characteristics and behavior of dairy cows of different calving orders in "milk first" robotic milking systems. The data were collected from a commercial herd located in the Midwest region of Minas Gerais (Brazil), which uses an automatic milking system (AMS TM, DeLaval). Were analysed 26,574 observations of 235 Holstein cows were available. Data were evaluated by multivariate analysis of variance and the Tukey test. - Tthe characteristics milk flow and milking efficiency were more favourable for multiparous cows (p <0.01), while the time in the stall was more favourable for primiparous females (p <0.01). The values of handling time were better in the primiparous cows (p <0.01). Primiparous cows had higher amounts of kick-off (p <0.001), and multiparous cows had higher incomplete milkings (p <0.001). The number of incomplete milkings showed a higher ratio in terms of reduction in milk production in 26.6% in primiparous cows and 26.7% in multiparous cows (p <0.01). Regarding the behavioral characteristics, primiparous cows had higher amounts of kickbacks, while multiparous cows had greater quantities of incomplete milkings.

Air velocity spatial variability in open Compost-Bedded Pack Barn system with positive pressure ventilation.

In Compost-Bedded Pack Barn (CBP) systems, air velocity is linked with the thermal comfort of housed dairy cattle and bedding quality and, therefore, assessing ventilation efficiency is essential. In this context, the objective of this study was to evaluate and characterize dependence and spatial distribution of air velocity at the 1.5 m height (vair,M) and at bedding level (vair,B) in an open CBP system with positive pressure ventilation. The study was conducted in 2021, in a facility located in the Zona da Mata region, Minas Gerais, Brazil. The facility area was divided into a mesh composed of 55 equidistant points, where vair,M and vair,B data were collected in the morning (09:00 a.m.) and afternoon (03:00 p.m.) periods, during three weeks in Brazilian winter. Geostatistics techniques were used to assess dependence and spatial distribution. In both periods evaluated, there were a strong occurrence of spatial dependence and non-uniform vair,M and vair,B distributions. The vair,M and vair,B values were lower than recommended (1.8 m∙s-1) in more than 65.0% of the area. Adequate ventilation levels were observed only in the first 20.0 m of the facility, from Southeast to Northwest, because of the fan lines present.

Spatial analysis of microclimatic variables in compost-bedded pack barn with evaporative tunnel cooling.

In this study, we aimed to assess the spatial variability of microclimate inside a closed compost-bedded pack barn (CBP) with a negative ventilation system during summer and winter. The research was carried out in a CBP located in the Zona da Mata region, Minas Gerais, Brazil. For each of the stations analyzed, the following environmental mean variables observed inside a CBP were measured: air dry-bulb temperature (tdb), air relative humidity (RH), and windspeed, Temperature-Humidity index, and specific enthalpy. The kriging maps showed that the most critical housing conditions in the thermal environment were found, mainly, from the central part of the CBP, close to the exhaust fans. The analyses also pointed out that the system presented temperature gradients along the length, up to 3°C. During the summer afternoon, the entire region of the CBP was in a discomfort situation (tdb>26°C; RH>75%). During the winter, the measured environmental data remained within the comfort zone throughout the facility. However, probably due to the lack of thermal insulation of the material used to close the sides of the CBP, it did not allow spatial thermal uniformity for both seasons. It was also inefficient to keep the animals within the comfort zone for lactating cattle during the critical summer period.

Assessment of spatial variability of bedding variables in compost bedded pack barns with climate control system.

The aim of this research was to evaluate the spatial distribution of bedding variables in a climate-controlled compost bedded pack barn (CBP) equipped with an evaporative cooling system associated with a tunnel ventilation mode. The study was conducted on a farm in the West Mesoregion of Minas, MG, Brazil. The interior of the animal facility was divided into a mesh of 120 equidistant points, where the bedding surface temperature (tb-sur), the bedding temperature at 0.20 m depth (tb-20) and the bedding penetration resistance (PRb) of layer 0 to 0.20 m depth were measured. Bedding samples were collected to obtain the moisture (Mb) and pH in the surface and at 0.20 m depth. Geostatistics technique was used to evaluate the dependence and spatial distribution. Through the bedding area, the tb-sur presented low variability, with 6 ºC of amplitude, and tb-20 presented highest values (up to 55 °C). The spatial distribution of Mb-20 was similar to that observed on the surface and its highest levels occurred in the region near the feed alley (> 40%). The distribution of pH was similar in both layers. The tendency of high PRb occurred in the layer between 0.15 and 0.20 m (0 and 1500 kPa).

Using infrared thermography to detect subclinical mastitis in dairy cows in compost barn systems.

This study aimed to evaluate the use of thermal imaging obtained by infrared thermography (IRT) to detect cases of subclinical mastitis in dairy cows under commercial conditions of compost barn systems in a region of Brazil with a semiarid climate. Twenty-eight crossbred cows were evaluated twice a day for one week using IRT. Three thermal images were obtained for each cow, referring to the anatomical regions of the right and left fore udder and rear udder. A computer program was used to analyze the images and obtain the right fore udder temperature (RFUT, °C), left fore udder temperature (LFUT, °C), rear udder temperature (RUT, °C), and average udder temperature (AUT, °C). In addition, samples of milk from each quarter of the udder were collected for somatic cell count (SCC) to correlate the diseases observed on the thermal image with any infection in the udder region. The results obtained using IRT were subjected to regression and correlation analyses. It was observed that LFUT, RAQT, RUT, and AUT were adjusted in quadratic polynomial models with good prediction of SCC (i.e., infection) with R2 = 0.92, 0.97, 0.86, and 0.94, respectively. The region of the anterior quarters of the udder was the most promising for imaging, stronger correlations were obtained between LFUT and RFUT with SCC (r = 0.87 and 0.88, respectively). The IRT is a practical technology capable of detecting cases of mastitis in dairy cows with good precision, especially with thermal images from the anatomical region of the front quarters of the udder. However, more detailed studies are needed to make thermal imaging processing a more useful method for routine activities on farms in compost barn systems.