Enhancing Postgraduate Learning and Teaching: Postgraduate Summer School in Dairy Science

Dairy science is a multidisciplinary area of scientific investigation and Ph.D. students aiming to do research in the field of animal and/or veterinary sciences must be aware of this. Ph.D. students often have vast spectra of research interests, and it is quite challenging to satisfy the expectation of all of them. The aim of this study was to establish an international Ph.D. training program based on research collaboration between the University of Sydney and the University of Padova. The core component of this program was a two-week Postgraduate Summer School in Dairy Science, which was held at the University of Padova, for Ph.D. students of both universities. Therefore, we designed a program that encompassed seminars, workshops, laboratory practical sessions, and farm visits. Participants were surveyed using a written questionnaire. Overall, participants have uniformly praised the Summer School calling it a rewarding and valuable learning experience. The Ph.D. Summer School in Dairy Science provided its participants a positive learning experience, provided them the opportunity to establish an international network, and facilitated the development of transferable skills

Thermographic study of the ovine mammary gland during different working vacuum levels

Thermography is a non-contact, non-invasive technique that detects surface heat emitted as infrared radiation. Because skin temperature reflects the status of underlying tissue metabolism and blood circulation, abnormal thermal patterns can signify areas of superficial inflammation or circulatory impairments (i.e. congestion). In sheep different methods have been adopted to measure udder blood circulation and the effect of cold exposure and lactation on the distribution of blood flow. The effect of milking procedures on udder and teat skin temperature was investigated in cows through thermographic scanning. Thermography results in a very useful tool to evaluate, estimate and differentiate short and longer-term tissue reactions to machine milking. The objective of this study was to evaluate the influence of working vacuum level on udder and teat temperature changes during milking procedures and the recovery by indirect monitoring of the circulatory impairments of teat tissue via infrared thermography. Two groups of six lactating Sarda ewes were milked experimentally at two vacuum levels (28 and 42 kPa) and same pulsation parameters (120 cycles/min and 60% ratio). Thermographic images (Flir System, ThermaCam P25, sensitivity of 0.08 °C) of posterior udder area (PUA) and teats (teat base – TB; mid teat – MT and teat tip – TT) were taken pre-milking (PM), during milking (M) (only for PUA), and immediately after milking (IAM) up to 2 minutes after milking (AM+). Temperatures were recovered by processing the thermographic images in ThermaCam Researcher Basic 2.8 SR-1 Software (Flir System). The PUA showed a drop of 1°C in both treatments between PM and M. After milking, values did not show remarkable changes. The vacuum level effect on teats temperature results to be different between treatments. Results during IAM indicate a general drop of the teats temperatures and specifically for high vacuum level (from 39.82 to 37.92°C and from 39.71 to 37.75°C for low and high vacuum level respectively). During AM+ (monitored up to 60 sec - AM +30; up to 90 sec - AM+60 and up to 120 sec – AM+90) the increase of teat temperatures were different (P<0.05) between vacuum levels (AM+30: 38.12 vs 37.54°C; AM+60: 38.19 vs 37.96°C and AM+90: 39.02 vs 38.58°C for low and high vacuum level respectively). Differences among TB, MT and TT were evident also at AM+90 only for the high vacuum level while in low one, at the same time, it was persistent only the difference between TT and TB. The higher teat temperature for the low vacuum level could be attributable to a faster return to a normal condition of the blood flow in all teat locations. Teat circulation impairments due to milking procedures need further surveys

Expression of selected genes related to energy mobilization and insulin resistance in dairy cows

The physiological and metabolic adaptation characterizing the transition period in the dairy cows is developed by a complex modulation of different metabolic pathways as well as the expression of selected tissue-specific gene. The aim of this study was to evaluate the age effect on expression of selected genes in adipose, hepatic and muscle tissues in dairy cows during their dry period using the quantitative Real Time Polymerase Chain Reaction (qRT-PCR). Twenty-two pluriparous dairy cows were divided into 3 groups in relation to the age: Group A (38 \uc2\ub1 2 months); Group B (52 \uc2\ub1 2 months) and Group C (80 \uc2\ub1 8 months). Lower levels of peroxisome proliferator-activated receptor gamma (PPARG) and higher levels of adiponectin (ADIPOQ) were found in adipose tissue in Group C than Groups A and B (P < 0.05). Higher levels of solute carrier family 2/facilitated glucose transporter member 4 (SLC2A4) were found in muscle in Group C than Group A (P < 0.001) and Group B (P < 0.05). The present study showed in dairy cows that the expression of selected genes associated with mobilization of energy and with insulin resistance are influenced by age demonstrating and highlighting the importance of a genomics approach to assess the metabolic status of dairy cows during the transition period

Adaptation of some energetic parameters during transition period in dairy cows

The aim of this study was to evaluate the effect of peripartum period and lactation class on serum β-hydroxybutyrate, non-esterified fatty acids (NEFA), insulin and glucose concentration in dairy cows. Thirty-five multiparous Holstein cows were selected from a high-producing dairy farm. The animals were divided according to their lactation class: second lactation group (L2, n = 16), third lactation group (L3, n = 10) and fourth lactation group (L4, n = 9). Blood sampling were performed 7 ± 5 days before calving (Pre/C) and 7 ± 5 days after calving (Post/C). Two-way analysis of variance was applied to determine significant effects of lactation class (L2, L3 and L4) and period (Pre/C and Post/C) on studied parameters. Increased NEFA values and lower insulin levels were found in Post/C respect to Pre/C in L2 and L4. These changes highlight the difficulty of dairy cows to cope with the energy demand characterizing the transition period. Improving in knowledge of energetic metabolism changes may help to supply a new strategy of farm management and reproductive performance in dairy cows during the transition period

Glucose infusion response on some metabolic parameters in dairy cows during transition period

Abstract. The aim of this study was to evaluate the effect of glucose tolerance test (GTT) on glucose, insulin, non-esterified fatty acids (NEFA) and β-Hydroxybutyrate (BHB) concentration in dairy cows during prepartum and postpartum period. Forty Two clinically healthy Holstein cows were enrolled in two high producing dairy farms in the Northeast Italy. All animals were divided into two equal groups on the basis of the farm of origin: Group A (farm located in Vicenza) and Group B (farm located in Padua). Body condition score (BCS) was determined for both groups. GTT was performed 7 ± 5 days before and 7 ± 5 days after calving. Blood samples were collected from each animal before (T0) and after the administration of glucose at different times. Plasma concentration of glucose, insulin, NEFA and BHB was evaluated. Application of two way analysis of variance (ANOVA) showed no significant effect of farm and a significant effect of transition period (prepartum and postpartum) on BCS for both groups. Multivariate analysis of variance (MANOVA) was applied to determine significant effects of infusion glucose time, transition period and farm on glucose, insulin, NEFA and BHB. No significant difference was observed between Groups A and B and a significant effect of transi tion period and glucose infusion was found on all parameters studied. Results confirm that glucose is an important direct controller of metabolic response in dairy cows during the transition period because of the inappropriate energetic supply that characterizing this physiological phases