Effects of the Physiological Status and Diet on Blood Metabolic Parameters in Amiata Dairy Donkeys

An Investigation on the Effects of Partial Replacement of Rapeseed Cake in Ayrshire Dairy Heifers' Diets with By-Product Source of Animal Protein on Body Weight Dynamics, Nutrient Balancing, and Blood Biochemical Markers

Recently, the secondary use of by-products of the processing industry resulting from the production of poultry meat, which can be included in animal diets, has become a popular topic in the feed industry. For studying the effects of partial replacement of rapeseed cake (RC) with the by-product source of animal protein concentrate Agro-Matic (PCAM) on growth dynamics, nutrient absorption and nitrogen balance, as well as blood biochemical parameters during the growing period, a total of 48 Russian Ayrshire dairy heifers were selected for this experiment and they were divided into three experimental groups (16 in each group, including the control group). The heifers of the control group were fed the basal diet which contained rapeseed cake (30%), while the second (RC + PCAM) and third groups (PCAM + RC) were fed the basal diet after replacing a part of the rapeseed cake with 2.25% and 4.5% of protein concentrate Agro-Matic respectively. The results showed that the weight of heifers treated with PCAM at 3 months of age exceeded the control by 2.3 kg (p > 0.05) in group 2 by 4.4 kg (p < 0.05). Similar results were obtained at the age of 6 months of raising. Feeding 4.50% protein concentrate Agro-Matic has a positive effect on the digestibility of nutrients; in particular, there was a significant increase in the digestibility of crude protein in the PCAM + RC group (77.23 vs. 73.42%) compared with the control group. Moreover, a similar trend was found in the digestibility of nitrogen in the diet. At the age of 3 months, heifers showed a significant decrease in the concentration of ketone bodies in the second group (1.82 vs. 2.20 mmol/L) relative to the control group. Urea was significantly lower in the RC + PCAM group (5.05 vs. 6.62 mmol/L) relative to the PCAM + RC group, while acid capacity (alkaline reserve) was higher by 2.41% (p < 0.05) relative to the control. In the 10th month of age, a positive effect on the blood of heifers was observed, as in the second and the third experimental groups, β-globulin and phosphorus increased (p < 0.05), while in the second group aspartate aminotransferase decreased (p < 0.05). Consequently, replacing the rapeseed cake with the protein concentrate Agro-Matic revealed an improvement in the dynamics of growth, nutrient digestibility and nitrogen balance, and it has an effect on improving some biochemical parameters of the blood.

Evaluation of Ultrasound Measurement of Subcutaneous Fat Thickness in Dairy Jennies during the Periparturient Period

Simple Summary

Ultrasonography is an accurate method to objectively measure subcutaneous fat (SF) thickness and to routinely predict body fat reserves in cows, horses, and donkeys. The aim of the present study was to describe ultrasonographic SF thickness in periparturient jennies. The SF was evaluated in 6 different truncal location in 6 dairy jennies prior and post parturition. Measurement values were reported and each site were compared through time. No statistically significant differences were found between sites and time. The mean values of SF measurements were above those reported by others. A good and reliable association was detected between body condition score (BCS) and sites during the whole study period. Our study gives a preliminary description of different body locations fat reserves evaluated by ultrasonography, showing no significative variations, in pregnant and lactating jennies.

Abstract

The body condition score (BCS) represents a practical but subjective method for assessing body fat reserves. Real time ultrasonography (RTU) has been proposed as an accurate method to objectively measure subcutaneous fat (SF) thickness and predict body fat reserves in cows, horses and donkeys. The aim of the present study was to describe RTU measures of SF thickness during periparturient period in jennies. The present prospective cohort study evaluated six dairy jennies. SF RTU were performed at 15 and 7 days before the presumptive delivery, and 2, 15 and 30 days after delivery. A portable ultrasound machine and multifrequency linear transducer (5–7.5 MHz) was used. RTU images were obtained in six sites (S1–S6). Results at each time point were reported as mean ± standard deviation and compared through time. A total of 180 images were evaluated. RTU technique was easy to perform and well tolerated. No statistically significant differences were found of each site during time, except for S2 and S6a: S2 at T2 and S6a at T1 were significatively different to values obtained at T5. The RTU mean values were above those reported by others, suggesting major physio-logical challenges related to energy balance and fat mobilization in pregnant jennies bred for milking production. BCS and sites through observational time have shown a good and reliable association. Our study could give preliminary indications on fat reserves in different body locations evaluated thanks to RTU and it show no significative variation of SF thickness, in pregnant and lactating jennies.