F. Piccioli Cappelli

Effect of summer season on milk protein fractions in Holstein cows

Milk characteristics are affected by heat stress, but very little information is available on changes of milk protein fractions and their relationship with cheesemaking properties of milk. The main objective of the study was to evaluate the effect of hot season on milk protein fractions and cheesemaking properties of milk for Grana Padano cheese production. The study was carried out in a dairy farm with a cheese factory for transforming the milk to Grana Padano cheese. The study was carried out from June 2012 to May 2013. Temperature and relative humidity of the inside barn were recorded daily during the study period using 8 electronic data loggers programmed to record every 30 min. Constant managerial conditions were maintained during the experimental periods. During the experimental period, feed and diet characteristics, milk yield, and milk characteristics were recorded in summer (from June 29 to July 27, 2012), winter (from January 25 to March 8, 2013), and spring (from May 17 to May 31, 2013). Milk yield was recorded and individual milk samples were taken from 25 cows selected in each season during the p.m. milking. Content of fat, proteins, caseins (CN), lactose and somatic cell count (SCC), titratable acidity, and milk rennet coagulation properties were determined on fresh samples. Milk protein fraction concentrations were determined by the sodium dodecyl sulfate-PAGE. Data were tested for nonnormality by the Shapiro-Wilk test. In case of nonnormality, parameters were normalized by log or exponential transformation. The data were analyzed with repeated measures ANOVA using a mixed model procedure. For all the main milk components (fat, protein, total solids, and solids-not-fat), the lowest values were observed in the summer and the greatest values were observed in the winter. Casein fractions, with the exception of γ-CN, showed the lowest values in the summer and the greatest values in the winter. The content of IgG and serum albumin was greater in summer than in the winter and spring. A mild effect of season was observed for milk SCC, with greater values in summer than in the winter and spring. A worsening of milk coagulation properties was observed in summer season. The alteration of cheesemaking properties during hot season seems strictly linked with changes of milk protein fractions mainly with the decrease of αS-CN and β-CN and the increase of undefined proteins.

Effects of the precalving administration of omega-3 fatty acids alone or in combination with acetylsalicylic acid in periparturient dairy cows.

This study investigated the effects of the administration of long chain omega-3 fatty acids (ω-3 FA) and acetylsalicylic acid (ASA) on inflammation, performance, and fertility in periparturient dairy cows. Five weeks before calving, 26 multiparous dairy cows were randomly assigned to 1 of 3 treatments: ω-3 FA (n = 9; OME), ω-3 FA and ASA (n = 9; OMAS), or palm oil (n = 8; CTR). During the last 3 wk of pregnancy, OME and OMAS groups received daily 12.0 g of fish-derived ω-3 FA, whereas CTR cows received only SFA. In addition, OMAS cows received daily 6.0 mg ASA/kg BW starting at 7 d before calving. Only a few cows had health problems after calving, but those in OMAS were most affected (n = 3 vs. 1 in CTR). Inflammatory status around calving did not improve in OME cows, as confirmed by the patterns of concentration of acute-phase proteins (APP), which were similar to CTR. Compared with CTR and OME, the increase of the positive APP and the decrease of the negative APP (e.g., albumin; P < 0.01) observed in OMAS cows suggested a severe inflammatory status after calving. Compared with OMAS, postcalving energy metabolism was better in OME cows as shown by a lower degree of lipomobilization (smaller BCS drop, greater glucose) and milder ketogenesis (less β-hydroxybutyrate; P < 0.01). Cows in CTR had optimal fertility indices, whereas OMAS was the worst group. The severe inflammation and the more negative energy balance likely contributed to the poor fertility parameters in those cows. It is known that ASA exerts an inhibitory effect on cyclooxygenases, causing a possible decrease in the synthesis of PGF2α. A decreased concentration of PGF2α is connected with alterations in the physiologic processes related to labor and to uterine motility. Cows in OMAS had a longer pregnancy (P < 0.10 vs.OME) and a greater frequency of retained placenta, which may be attributed to decreased synthesis of PGF2α. The administration of ω-3 FA alone did not delay calving or the expulsion of fetal membranes. In conclusion, long-chain ω-3 FA improved the physiological status of cows, partly through better energy balance. The administration of ASA before calving (even at a low dose) in combination with ω-3 FA did not exert any synergistic positive effect on inflammation and performance.

Variations of some blood parameters in rabbit reared under different environmental conditions

Riassunto Variazioni di alcuni parametri ematici in conigli allevati in differenti condizioni ambientali. Presso un allevamento commerciale di conigli, una medesima prova di allevamento è stata condotta, dallo svezzamento a fine ingrasso, in condizioni di clima fresco e caldo, controllando accrescimenti, consumi alimentari, caratteristiche del contenuto ciecale e profilo metabolico. Lo stress da caldo ha indotto variazioni nei parametri ematici solo in parte correlabili al riscontrato calo di ingestione. Le più consistenti relazioni tra caratteristiche del contenuto ciecale e variazioni metaboliche in condizioni di stress termico indicano una maggiore criticità delle caratteristiche delle diete in tali situazioni.

Glutathione peroxidase responses in mature horses following the withdrawal of an organic selenium supplement

Abstract The study comprised 25 mature horses and incorporated five dietary treatments; a negative control (C: 0.085 ppm of Se in the diet), 3 levels of organic Se supplementation (S2, S3 and S4; 0.2, 0.3 and 0.4 ppm of Se on DM respectively) and one positive control supplemented with Na selenite (N3: 0.3 ppm of Se on DM). Diets were offered for 112 days (supplementary period) after which horses were blood sampled to determine GSH-Px activity. Sampling was repeated at 28 day intervals for the following 112 days (post-supplementary period). Increased GSH-Px activity was observed with ascending concentrations of dietary Se following the supplementary period. GSH-Px activities are still notably higher at the end of the post-supplementary period in S2, S3, S4 and N3 when compared to C, although rates of decline were greatest in those treatments with the highest levels of selenium supplementation. Furthermore, GSH-Px activity was better maintained in those animals that had received organic Se following the withdrawal of Se supplements. Therefore, from a nutritional viewpoint, organic forms of Se are superior to selenite as GSH-Px activity is maintained during periods of Se inadequacy.

Pattern of γ-glutamyl transferase activity in cow milk throughout lactation and relationships with metabolic conditions and milk composition

The main objective of this experiment was to study the γ-glutamyl transferase (GGT) activity in milk during lactation and its relationship with metabolic status of dairy cows, milk yield, milk composition, and cheesemaking properties. The study was performed in a tied stall barn and involved 20 lactations from 12 healthy multiparous Italian Friesian dairy cows. During lactation starting at d 10, milk samples were collected weekly and analyzed for composition, somatic cells count, titratable acidity, and milk coagulation properties. The GGT activity was measured in defatted samples. Blood samples were collected weekly to assess biochemical indicators related to energy, protein, and mineral metabolism, markers of inflammation and some enzyme activities. The lactations of each cow were retrospectively categorized into 2 groups according to their milk GGT activity value through lactation. A median value of GGT activity in the milk of all lactations was calculated (3,045 U/L), and 10 lactations with lower GGT activity were classified as low while 10 lactations with greater GGT activity were classified as high. The average value of milk GGT activity during lactation was 3,863 and 3,024 U/L for high and low, respectively. The GGT activity decreased in early lactation and reached minimum values in the second month (3,289 and 2,355 U/L for high and low, respectively). Thereafter GGT activity increased progressively, reaching values in late lactation of 4,511 and 3,540 U/L in high and low, respectively. On average, milk yield was 40.81 and 42.76 kg/d in high and low, respectively, and a negative partial correlation with milk GGT activity was observed. A greater milk protein concentration was observed in high (3.39%) compared with low (3.18%), and a positive partial correlation with milk GGT activity was observed. Greater titratable acidity in high than that in low (3.75 vs. 3.45 degrees Soxhlet-Henkel/50 mL, respectively) was also observed. Plasma glucose was greater in cows of high than in low group, while plasma urea was lower in the high than in the low group. No relationship between plasma GGT and milk GGT activity was observed. Our results show an important effect of lactation stage on milk GGT activity. The individual effect observed from consecutive lactations and the relationship between milk GGT activity and milk protein concentration in healthy cows could open prospects for GGT as a future tool in improving milk protein content.

Change of selenium in plasma of dairy cows receiving two levels of sodium-selenite during the transition period

Abstract With the aim to study the plasma Se content during transition period, 2 groups of 12 dairy cows were monitored the month before and after calving. In stall 1 (S1) cows were tied and individually fed, in stall2 (S2) cows were free and fed TMR. In both stalls cows were supplied with Se as Na-selenite. In S1 3 mg/d of Se were fed mixed with corn silage while, in S2, Se was offered with TMR, in dry period 2 mg/d were added with a mineral-vitamin supplement, in lactation 2.6 mg/d (when DMI was 22.2 kg/d) with the concentrate. Forages, the same for both stalls, and concentrates were sampled for chemical composition and Se determination. Cows were checked for milk yield and its content of somatic cells (SCC), health problems, and bled for Se determination in plasma. Average Se intake was higher in S1, in both dry (4.08 vs 2.76 mg/d) and lactating (5.80 vs 2.11 mg/d) period. Besides the supplementation, differences depended on high Se intake in S1 with the concentrate (increased after calving to 11.5 kg/DM on d 30 and containing 0.24 mg/kg DM of Se). According to the intake, plasma Se content resulted higher in S1 in dry (1.20 vs 0.74 µmol/L) and lactating (1.47 vs 0.62 µmol/L) cows. In close-up plasma Se decreased in both groups, in first days of lactation increased in S1, while decreased in S2 to level indicating a deficient intake (0.50 µmol/L). These results confirm the link between Se intake and its plasma level. Finally, Se plasma content did not seem related to cow health status during transition period.

Effect of some disease stress on cow milk yield and features

Riassunto Effetti indotti da diversi problemi di salute sulla produzione e caratteristiche del latte bovino. 9 bovine con problemi infiammatori sono state divise in due gruppi in funzione del calo di ingestione di alimenti e produzione di latte: 5 non hanno evidenziato alcun calo (IG); 4 un calo marcato (AG). Il latte è stato controllato per 21 giorni prima e 21 dopo l’evidenza dei problemi. In entrambi i gruppi nel periodo di manifestazione dei problemi il tenore in proteina del latte non è variato, l’acidità è diminuita significativamente, mentre le caratteristiche reologiche sono peggiorate e in AG questo si è protratto sino a 7 giorni dopo. A livello delle frazioni proteiche la variazione che parrebbe giustificare questo peggioramento è stata la riduzione della β-caseina, osservata in entrambi i gruppi e solo in AG sino al termine dei controlli. I dati ottenuti confermano che lo stress infiammatorio determina condizioni che modificano le caratteristiche del latte, tra cui anche la frazione proteica, e che le alterazioni sono più marcate in concomitanza di fenomeni di anoressia.

Estimation of dry matter intake by n-alkanes in dairy cows fed TMR: effect of dosing technique and faecal collection time

Estimation of individual intakes in dairy cows would be beneficial to select animals according to efficiency of milk production. The n-alkanes technique has been used to estimate intake by dairy cows in free stall barns, limiting faecal samples to one or two per day, but diurnal variation in the ratio of dosed to natural alkanes in faeces represents a source of error. We aimed to adapt this technique to estimate feed intake on a large number of lactating dairy cows housed on commercial dairy farms. Using a change-over design, six lactating cows fed a TMR diet were given a dose of 0.5 g/day of C32 n-alkane administered once a day as a drench (DRE) or top fed (TP). Feed offered and refused were weighed daily. After the lead-in phases, faeces were collected at 0700 hours, 1400 hours and 1900 hours on the last 5 days of each dosing period. Dry matter intake (DMI) was estimated from C31, C33 and C32 concentrations in feeds and in faeces for each dosing system and sampling time. DMI estimated from C31 : C32 ratio was better correlated with measured individual DMI than estimates from C33 : C32 ratio. For DRE, the best correlation was for sampling at 1400 hours (R2 = 0.96, P < 0.001), but estimated DMI for the 1400 hours sampling was much higher than the actual DMI. For TP, the best correlation was for sampling at 0700 hours (R2 = 0.83, P < 0.001). Feeding C32 n-alkane and collecting faeces once a day at the same time (0700 hours) represents a valuable protocol to measure individual intake on a large number of animals.

Effects of dietary changes on milk yield and quality and metabolic profile in dairy cattle

– Dietary changes can negatively affect digestive processes, particularly at ruminal level and mainly when rapid and associated with an increase of fermentable carbohydrates (Owens et al., 1998). Milk quality can also be affected by digestive functionality (Bertoni et al., 1992). Excesses of degradable N boost blood and milk urea levels but these latter parameters are also influenced by the amount of escape protein fed, the aminoacid profile of absorbed protein and the energy availability (Westwood et al., 1998). Some field experiences indicated increases of milk urea after reformulation of diets to change some ingredients,.......

Single nucleotide polymorphisms in collagen genes and association with skin quality trait

Abstract Livestock skin is largely employed in the manufacturing of clothing and shoes, sector in which Italy is a world leader. To sustain Italian products against foreign competition in the globalization era particular attention is to be focus on product quality. Here we investigate the association of SNP mutations in genes coding for collagen proteins present in animal skin with a number of phisico-chemical parameters influencing skin quality for the tanning industry. Skin and blood were sampled from 73 Italian Friesian and Italian Brown bovines and from 43 Bergamasca and Sarda ovines, classified by sex and age. Skins were characterised for a set of chemico-physical parameters (thickness, density, humidity, protein content, ashes, lipid content, hydrossi-proline and DNA content). Regions of the collagen type I, III and IV were screened for SNP discovery in the two species by sequencing a set of reference animals. In bovine 15 polymorphisms were identified: (2 in collagen type I, 9 in collagen type III alpha 2; 4 in collagen type IV alpha 3). In ovine 21 SNPs were detected (7 for collagen type I, 7 in collagen type III alpha 2, 8 in collagen type IV alpha 3). Association analysis between SNP variants and traits was carried out by single marker ANCOVA within species, considering the breed as categorical predictor and the age in months as continuous predictor. One SNP in ovine and two in bovines resulted significantly associated (P <0,05) with one or more skin traits.