VN May 2021

Vetnuus | Mei 2021 40 the horses. The floor was instrumented with 24 shearbeam load cells to measure the vertical load imposed by each horse and its horizontal motion. Two horses were driven on a 56 km trip on both rural and urban roads. Load data were collected at 100 Hz for the 58-minute trip and were filtered with a cut-off frequency of 5 Hz using a Butterworth low-pass filter and then vertical acceleration computed. A pivot table counted sign reversals in the vertical acceleration signal, and vertical displacement was calculated using the fundamental frequency of the resulting acceleration data. Total vertical motion was calculated by making the negative displacements absolute and summing these with the positive displacements, and vertical work done was calculated by multiplying the force by the displacement measures. Horizontal motion was calculated by averaging the transverse and cranio-caudal position of the centre of pressure every second and adding the resultant displacements. Absolute vertical displacement of the two horses was 69.55 m and 97.56 m. In addition to the work done by standing, vertical work done in response to vibration was 322.4 kJ and 443.2 kJ. Horizontal excursion was 227.1 m and 243.0 m. This is a first effort to quantify the additional workload imposed on animals during transport, which will aid in the design of smart transport vehicles that will minimise the stress to horses. v (Source: Journal of Equine Veterinary Science , Volume 99, April 2021, 103408) The objective of the current experiment by Jomari Badillo Delos Reyes and co-workers was to investigate the effects of dietary supplementation of vitamin C on productive performance, egg quality, tibia characteristics and antioxidant status in laying hens raised under normal temperature conditions. A total of 504 46-week- old Hy-Line Brown laying hens were allotted to 1 of 6 dietary treatments with 7 replicates in a completely randomised design. A commercial-type basal diet was formulated without inclusion of supplemental vitamin C. Five treatment diets were prepared by adding 250, 500, 1000, 2000 or 3000 mg/kg vitamin C to the basal diet. Hens were raised under normal temperature conditions (20.3°C of room temperature and 60% of relative humidity, on average) for 6 weeks. Results indicated that increasing supplementation of vitamin C increased (quadratic, P < 0.05) hen-day egg production and egg mass, and decreased feed conversion ratio (quadratic, P < 0.05) and the incidence of broken and shell-less eggs (linear and quadratic, P < 0.01). The positive effects on productive performance were observable for hens fed diets supplemented with 250 mg/kg vitamin C, but no further improvements at the supplemental levels of over 250 mg/kg vitamin C were identified. Egg quality, tibia characteristics and liver antioxidant status were not affected by increasing supplementation of vitamin C in diets. Gene expression of L-gulonolactone oxidase was increased (linear, P < 0.05) in the kidney by increasing supplementation of vitamin C in diets; however, this increase was not observed in the liver. Increasing supplementation of vitamin C in diets improves productive performance of laying hens but has no effects on egg quality and tibia characteristics. The quadratic improvements in productive performance suggest that dietary supplementation of 250 mg/kg vitamin C is recommended for laying hens raised under normal temperature conditions. v POULTRY Effects of dietary supplementation of vitamin C on productive performance, egg quality, tibia characteristics and antioxidant status of laying hens (Source: Livestock Science, Volume 248, June 2021, 104502) FARMANIMALS Relationship between body condition score index and fertility in beef cows subjected to timed artificial insemination Visual evaluation of body condition score (BCS) is an important method for the subjective quantification of body energy reserves in cattle. The objective of this study by Luiz Francisco Machado-Pfeifer and co- workers was to develop an index to estimate the relationship between BCS and fertility, using 2321 lactating Nelore cows from 29 cohorts in Mato Grosso do Sul and Rondonia states, Brazil enrolled in timed artificial insemination (TAI) programs. All females were evaluated according to BCS (scale 1 to 5) and were included in an estradiol-progesterone-based TAI protocol. Oestrus scores were evaluated (scale 1–3) for all cows at TAI. The cows in each TAI protocol were categorised according to pregnancy per AI (P/AI) into low (< 45%, LF), moderate (45%–60%, MF), and high (>60%, HF) fertility groups. To evaluate whether the BCS of each cow was in accordance with the target BCS (3 to 4) for beef cows to be enrolled in TAI programs, three variables were calculated: (1) adequate BCS rate (ABR), in which cows with BCS on target received 100% and cows with BCS values outside the target range received 0%; (2) the difference between the real BCS and the target BCS (DBCS); and (3) the adjusted DBCS (ADBCS), in which DBCS was transformed into an inverse value. Finally, the average between ABR and ADBCS resulted in a BCS index (BCSi). Analysis of variance was used to compare BCSi, BCS, and oestrus scores among fertility groups, and Tukey's test was used to compare means among groups. There were differences in BCSi between fertility groups ( P <0.05). Both the BCSi and BCS were highest in the HF groups, which also showed the highest oestrus scores. However, the BCSi provides information that takes into account the proportion of cows with or without adequate BCS, and could be more useful to apply in practice. The results demonstrate that determining the BCSi presents a novel approach that is highly associated with fertility in TAI programs. v (Source: Livestock Science, Volume 248, June 2021, 104482) Recent Clinically Relevant Research from Around theWorld