A. Gramenzi

Effect of dietary antioxidant supplementation on fresh semen quality in stallion.

In this study, the effect of dietary supplementation of organic selenium, vitamin E, and zinc on raw semen characteristics was evaluated. Ten stallions with normal fertility were divided into two groups: a control group (CG), in which standard diet was provided, and a treated group (TG), in which the standard diet was supplemented with 1500 mg of α-tocopherol acetate, 360 mg of zinc, and 2.5 mg of organic selenium on a daily basis. Semen parameters on fresh semen were evaluated three times in all stallions before antioxidant supplementation (T0) and 30 (T1), 60 (T2), and 90 (T3) d after supplementation. Dietary supplementation with experimental antioxidants resulted in a significant increase in average path velocity (121.9 ± 3.1 μm/sec in TG vs 118.9 ± 4.3 μm/sec in CG), straightness (86.2 ± 2.4 % vs 82.6 ± 3.9 % in TG and CG respectively), viability (75.6 ± 10.2 % in TG vs 72.3 ± 6.9 % in CG) and total seminal plasma antioxidants levels (2.7 ± 0.5 mmol/l vs 1.9 ± 0.4 mmol/l in TG and CG respectively) while progressive motility 69.7 ± 11 % vs 62.2 ± 9.3 % in TG and CG stallions respectively) and abnormal sperm morphology (8.2±1.5 % in TG vs 14.4±4 % in CG) significantly improved in treated stallions after 60 d of supplementation. In contrast with previously reported in other species, a negative effect of antioxidant supplementation on semen concentration was recorded in the TG. A positive correlation between progressive motility and total antioxidants in seminal plasma in both treated and control stallions suggested that motility is affected by oxidative-antioxidative status, and that dietary antioxidant supplementation could increase the ability of spermatozoa to contrast reactive oxygen species or the ability of seminal plasma to reduce the oxidative stress. The improvement of semen parameters after antioxidant supplementation was not linear, and after 30 d (or 60 d for some parameters), a further increase was not noted. This evidence suggested that in our standard conditions, dietary intake of these antioxidants could be slightly under the dietary requirement and further evaluation of the actual nutrition requirements of organic selenium, zinc, and vitamin E in the stallion are needed.

Effect of dietary supplementation with methionine on cheese-making properties

Riassunto Effetto dell’integrazione della dieta con metionina sulle caratteristiche casearie del latte. Sono stati messi a confronto due gruppi omogenei di bovine in lattazione che hanno ricevuto diete ipoproteiche (13% S.S.) integrate o meno con DL-metionina ruminoprotetta. I risultati dimostrano che bassi tenori proteici ottenuti con diete prive di soia sono compatibili con elevate produzioni. Nel latte l’urea si mantiene bassa (20 mg/100 ml) e la qualità dello stesso risulta buona. L’integrazione delle diete ipoproteiche con metionina stimola la produzione ma, verosimilmente per un effetto “diluizione”, ne riduce significativamente il contenuto di proteine e di lattosio. Le caratteristiche casearie non risultano influenzate (eccezion fatta per l’acidità) dalla metionina ma le rese in formaggio sono inferiori nel gruppo trattato. In ogni caso la quantità stimata di formaggio prodotto dalle vacche trattate è leggermente superiore in relazione alla produzione media giornaliera più elevata.

Effects of a single injection of Flunixin meglumine or Carprofen postpartum on haematological parameters, productive performance and fertility of dairy cattle

The objective of the present research was to evaluate the effects of a single injection of Flunixin meglumine (FM) or Carprofen postpartum on haematological indicators, productive performance and fertility of Italian Friesian dairy cattle. In total, 60 cows, including 42 multiparous and 18 primiparous, were assigned to one of the following three treatments: (1) FM (2.2 mg i.m./kg of bodyweight (BW); Meflosyl 50 mg/mL), (2) Carprofen (CA; 1.4 mg s.c./kg of BW; Rymadil 50 mg/mL) or (3) saline (control) at 2.0 mL s.c./45.5 kg of BW. All treatments were administrated by a single injection within 12 h after calving. Individual milk yield was daily recorded during the trial and composition was determined at 7, 14, 21, 28, 35 and 60 days in milk (DIM). BWs were recorded at –21 ± 5 days before calving, and 1, 7, 14, 21, 28, 35 and 60 days after calving before the morning milking. Individual blood samples were collected from each animal for haemato-biochemical evaluation 3 weeks before calving (T0) and then repeated at the following times: within 12 h after calving, immediately before the administration of the anti-inflammatory drug (FM or CA; T1), ~36 h after calving (T2), 4 days after calving (T3) and 11 days after calving (T4). At each sampling time, the rectal temperature and the heart rate were monitored. Body condition score was determined after each sampling time and at 35 and 60 DIM. FM and CA treatments did not influence rectal temperature and heart rate during the first 11 DIM; no differences in overall milk yield, milk composition and dry matter intake were found. BW and body condition score were not affected by treatments throughout the study. Treatments did not affect serum metabolite concentrations of glucose, non-esterified fatty acids, β-hydroxybutyrate, serum urea nitrogen, total protein and albumin. Control cows showed a higher culling rate (P < 0.05) than did the FM- and CA-treated cows (25% vs 15% vs 5% respectively). FM-treated multiparous cows had a significantly (P < 0.05) lower incidence of retained placenta than did control and CA-treated cows (2.3% vs 9.3% vs 14% respectively). Furthermore, a greater percentage of cows pregnant (35% vs 10%) at the first insemination (P < 0.001) in non-steroidal anti-inflammatory drug groups than in control was found. Our findings evidenced that a single injection of FM or CA to non-febrile cows immediately after parturition could positively affect the metabolic adaptation of the cows at the onset of lactation and this aspect can positively influence reproductive performances and the culling rate.