https://hdl.handle.net/20.500.12008/27969 2026-04-23T11:57:11Z https://hdl.handle.net/20.500.12008/53192 Título: Relationship between energy balance and key blood metabolites in primiparous dairy cows at different calving conception interval Autor: Stefanello, Simone; Santos Amaral, Carolina dos; Cantarelli, Camila; Kozloski, Gilberto Vilmar; Cajarville, Cecilia; Repetto, José Luis; Mendoza Aguiar, Alejandro; Marques Portela, Valério; Quites Antoniazzi, Alfredo Resumen: This study identified the relationship between energy balance and some blood metabolites in primiparous dairy cows with different calving conception interval. Twenty primiparous Holstein-Friesian dairy cows were grouped according to the interval (days) from calving to conception into early-conception (early-c; <100 days), mid-conception group (mid-c; 100 – 150 days) or late-conception (late-c; >150 days) group; and evaluated on day -7 prior to parturition, and days 28, 56 and 90 postpartum. All groups presented positive energy balance, serum concentrations of HDL, urea-N and progesterone with no difference on days 28 and 56 of lactation. On day 90 of lactation all the cows presented negative energy balance; however, the early-c group presented a less intense (P < 0.05) net energy balance (-1.09 versus -2.15 and -1.86 Mcal/day), lower concentrations of serum urea-N (3.28 versus 4.22 and 4.88 mg/dL) and HDL cholesterol (0.84 versus 1.59 and 1.46 mmol/L) and greater serum concentration of progesterone (8.13 versus 4.54 and 1.83 ng/mL) than cows of mid-c and late-c groups, respectively. In conclusion, different from those usually observed for multiparous dairy cows, the energy balance during the first weeks of lactation was not a determining factor affecting the calving conception interval of primiparous dairy cows in the present study. Instead, the nutritional status and the serum concentration of urea-N and progesterone at a later stage, after 56 days of lactation, suggest having a role in delaying these cows’ pregnant status. 2024-01-01T00:00:00Z https://hdl.handle.net/20.500.12008/53179 Título: Oral sugar and vasopressin: Possible alternative in the management of ovine pregnancy toxemia Autor: González Montaña, J.R; Martín-Alonso, María José; Cal Pereyra, Luis; Benech, Alejandro; Escalera-Valente, Francisco; Alonso-Diez, Ángel J. Resumen: Ovine pregnancy toxemia, a disease that affects adult ewes in the final stages of pregnancy and which is caused by a negative energy imbalance, requires the usage of dextrose substances for treatment. It has been proven that it is possible to induce reticular groove closure by means of an intravenous injection of lysine-vasopressin (LVP) at doses of 0.08 IU/kg B.W., which enables oral administration of glucose solutions that can be used in pregnancy toxemia therapy. The aim of this research is to compare the effectiveness of conventional treatment with i.v. glucose solution versus coadministration of LVP and a commercial sugar-water solution. This was administered orally to eight ewes to which we experimentally had provoked pregnancy toxemia by fasting. The use of commercial sugar, replacing other glucose solutions, could facilitate and cheapen the therapy for this disease significantly. The results obtained indicate that the joint administration of LVP and an oral solution of commercial sugar produce a noteworthy increase in glycaemia, which has a longer effect over time despite being less marked than with i.v. administration of glucose solution. Therefore, it could be used in the therapy of this disease. Besides, it is also able to normalize other parameters used to evaluate energy metabolism in ewes during the days of the trial. 2023-01-01T00:00:00Z https://hdl.handle.net/20.500.12008/52765 Título: Efecto de la esquila preparto en diferentes etapas de la preñez sobre la población folicular de la piel y características de la lana de la progenie en Merino Australiano Autor: Martín, Andrea; Cal Pereyra, Luis; Abreu Palermo, Mayra Cecilia; Campos Pregliasco, María Belén; Scaglione Sanson, Fiorella; Rodríguez, Pablo; Pinto-Santini, Livia; Cantou Mayol, María Inés; Vallejo, A.; Neimaur, Karina 2025-01-01T00:00:00Z https://hdl.handle.net/20.500.12008/52752 Título: Effect of prepartum shearing on serum thyroid hormone concentrations in Australian Merino sheep under extensive grazing conditions Autor: Martín, Andrea; Neimaur, Karina; Scaglione Sanson, Fiorella; Rodríguez, Pablo; Campos Pregliasco, María Belén; Abreu Palermo, Mayra Cecilia; Pinto-Santini, Livia; Cantou Mayol, María Inés; González Montaña, J.R; Cal Pereyra, Luis 2025-01-01T00:00:00Z