Giovanni Cristoforo Bomboi

Effects of short-term feed restriction on milk yield and composition, and hormone and metabolite profiles in mid-lactation Sarda dairy sheep with different body condition score

Ten Sarda dairy ewes (5 with high Body Condition Score: H-BCS, BCS>2.5; BW 48.8±5.4 kg; 5 with low BCS: L-BCS, BCS<2.5; BW 36.2±4.7 kg) were subjected, after 7-day preliminary (Prel) period, to short-term feed restriction (FR, 50% of nutrient requirements) for three days followed by refeeding (Re-Fed, 100% requirements) for three days. Milk yield and composition (protein, fat, lactose, MUN, SCC, fatty acids), and blood parameters (glucose, NEFA, BUN, insulin, GH, IGF-I, leptin) were monitored. Milk yield decreased during FR in both BCS groups: at day 3 it was 38% and 35% of Prel values in H- BCS and L-BCS ewes, respectively, reaching Prel levels at Re-Fed in both groups. Milk fat concentration was influenced by BCS×sampling, increasing in H-BCS ewes during FR, but not varying in L-BCS ewes throughout the trial. During FR, milk protein increased as milk yield decreased. There was no change in milk urea nitrogen concentration during FR, but this decreased in both BCS groups during Re-Fed. FR modified the FA profile of milk fat in both BCS groups, increasing LCFA at the expense of SCFA and MCFA. Some blood parameters (NEFA, GH and IGF-I) were influenced by BCS, whereas almost all parameters were influenced by sampling. There was a rapid return to initial levels in all parameters except milk urea, blood urea and insulin at Re-Fed.

Does Vitamin E or Vitamin E plus Selenium improve reproductive performance of rams during hot weather

Abstract The objective of this study was to determine the effect of Vitamin E (Vit E) and Selenium (Se) on semen quality, sexual activity, packed cell volume (PCV), and white blood cell counts (WBC) of Awassi rams during the hot season. Twelve Awassi rams were subdivided into three groups and treated for 90 days. Rams in the 1st group (T1) were treated twice weekly with 175 mg/ram vitamin E at intervals of 12h; rams in the 2nd group (T2) were treated on the same schedule with 70 mg/ram vitamin E plus 2800 mg selenium; and rams in 3rd group (T3) served as controls. Sperm quality (percentage of motile cells and percentage of morphologically normal cells) and quantity (sperm volume, and concentration) were recorded weekly. Sexual activity was tested by using the pen libido test at monthly intervals. Blood samples were taken before treatment and after the 1st, 2nd, and 3rd months. Semen quality was significantly affected by treatments: the ejaculate volume increased in T2 vs T1, and T3; mass activity and individual motility were increased in T1 and T2 vs T3. Sperm concentration was increased in T2 and T1 vs T3, and the percentage of dead and abnormal spermatozoa was reduced in T1 and T2 vs T3, though the differences were not statistically significant. Pen libido test showed reduced reaction time for the first mount in the 1st month in T2 and T1 vs T3. The number of serves was increased in groups T1 and T2 vs T3. There were no significant differences in PCV among groups. After 3 months from the beginning of treatments, the percentage of lymphocytes increased in T1 and T2 vs. T3, while the percentage of neutrophils was reduced in T2 vs T3 in the 2nd and 3rd months. The results of this experiment indicate that treatments with vitamin E alone or in combination with selenium improved semen characteristics and reproductive performance of Awassi rams during the hot season.

Comparison of laparoscopic and transcervical insemination with frozen semen in Sarda dairy ewes

Laparoscopic insemination with frozen-thawed semen is currently used for planned matings in the Sarda breeding programme. In order to find a fast and less intrusive artificial insemination (AI) method that could replace laparoscopic insemination, a field comparison of laparoscopic and transcervical techniques was carried out on 200 mature Sarda ewes. After AI, ewes were assigned to teaser and fertile rams for 2 months. Return rates and cumulative (AI + natural mating) lambing rates were recorded over three subsequent 23-day periods. Lambing rates to AI were significantly different (P 0·05) and reached 82% and 74% respectively. Ewes with body condition scores at AI higher than 2·75 showed better overall reproductive performance, but not higher pregnancy rate to AI. Plasma cortisol concentrations, sampled twice, before and after AI, were higher (P < 0·01) in the last sample, suggesting a stress response to insemination. Cortisol levels after AI were lower (P < 0·01) for ewes submitted to transcervical rather than laparoscopic insemination (P < 0·01). However, cortisol levels after AI were no greater than those recorded when ewes were restrained in a milking yoke different from that usually employed. Laparoscopic AI was confirmed as the most suitable technique for insemination offrozen semen in the Sarda breeding scheme.

Commercial human kits’ applicability for the determination of biochemical parameters in sheep plasma

Currently, several commercially available biochemical kits are validated for their use in human but not in animals. The purpose of this work is to demonstrate the applicability of human kits for alanine-aminotransferase, aspartato-aminotransferase, albumin, total protein, total cholesterol, and triglycerides in ovine plasma. Assays were validated according to international guidelines and stability was explored. Accuracy values were between 67 and 100%, and intra and interday precisions (%RSD) were <15% for all studied parameters. These results confirm the suitability of the studied human kits for their use in ovine plasma and they were used in plasma collected from pregnant ewes.

Effects of fibre and non-fibre carbohydrate and level of intake on microbial protein yield in Sarda sheep

Abstract Three studies using Sarda dairy sheep in dry, mid-lactation and late-lactation were carried out. Forty ewes for each physiological stage were fed 8 complete pelleted diets, which differed from each other in NDF and NFC content and source. Based on their main ingredient, diets were denominated: corn meal (CM), wheat middlings (WM), corn flakes (CF), barley meal (BM), corn cobs (CC), beet pulp (BP), alfalfa (AA), and soybean hulls (SH). In each study, rumen microbial protein (MCP) synthesis was estimated measuring urinary purine derivatives. In dry sheep, MCP synthesis was not affected by diet, while in mid- and late-lactation sheep dietary effects were observed. In mid-lactation, the highest MCP production was found for BM and BP (171 and 166 g/d, respectively), while the lowest was observed with AA (63 g/d). In late-lactation, the highest MCP yield (146 g/d) was observed in BP, while the lowest were for SH and CM. MCP synthesis, for each diet, was higher in mid-lactation than in late-lactation, which in turn were higher than in the dry period. Dry matter intake (DMI) was positively associated to MCP. The MCP synthesis was best predicted by dietary energy (NEL) or digestible organic matter intake (dOMI).