Cladodes of Opuntia ficus-indica (L.) as a source of bioactive compounds in dairy products.

Recently, the interest in improving livestock product nutraceutical profiles through sustainable feeding systems has increased. In this context, the overall quality and nutraceutical profiles were examined in dairy products obtained from 16 lactating Cinisara cows given an integrated feed in dry season with Opuntia ficus-indica cladodes. Two homogeneous groups of cows (milk yield: 6.3 ± 1.5 kg; body weight: 213 ± 55 kg) were fed with 2 different diets (CON: pasture and wheat bran; OFI: pasture, wheat bran, and cladodes), according to a 2 × 2 Latin square design. The bulk milk produced during the study was used to make Caciotta cheese and was analyzed at 0, 15, and 30 storage days. Milk and cheese samples were analyzed for chemical, physical, and microbiological traits. The nutraceutical and sensorial profiles, as well as the antioxidant capacity, were also determined in the final products. For milk, the urea content in individual samples was reduced in OFI but not in CON. In the cheese, integration of cladodes did not influence the starter cultures development with 2 strains of Streptococcus thermophilus, but it caused a higher content of polyphenols and a consequent greater antioxidant capacity and a change in the fatty acids profile. In particular, the caprylic, capric, lauric, myristic, and palmitic fatty acids were higher, as were the petroselinic, vaccenic, rumenic, and α-linolenic fatty acids. In contrast, the oleic and the γ-linolenic fatty acids were lower for OFI. The cheese from the OFI group showed better overall acceptability, and a higher yellow color, odor intensity, and butter flavor. The multivariate analysis well distinguished the cheeses belonging to the 2 groups. Further investigations should be conducted to formulate well-balanced diets that include cladodes for Cinisara lactating cows, but also to determine the content of other important bioactive compounds in fresh and treated cladodes, as well as their effects on animal welfare and production.

Effects of ewes grazing sulla or ryegrass pasture for different daily durations on forage intake, milk production and fatty acid composition of cheese.

Sulla (Sulla coronarium L.) forage is valued for its positive impact on ruminant production, in part due to its moderate content of condensed tannin (CT). The duration of daily grazing is a factor affecting the feed intake and milk production of ewes. In this study, the effects of grazing sulla pasture compared with annual ryegrass, and the extension of grazing from 8 to 22 h/day, were evaluated with regard to ewe forage intake and milk production, as well as the physicochemical properties and fatty acid (FA) composition of cheese. During 42 days in the spring, 28 ewes of the Comisana breed were divided into four groups (S8, S22, R8 and R22) that grazed sulla (S) or ryegrass (R) for 8 (0800 to 1600 h) or 22 h/day, and received no feeding supplement. In six cheese-making sessions, cheeses were manufactured from the 48 h bulk milk of each group. Compared with ewes grazing ryegrass, those grazing sulla had higher dry matter (DM) intake, intake rate and milk yield, and produced milk that was lower in fat and higher in casein. Ewes grazing for 22 h spent more time eating, which reduced the intake rate, increased DM and nutrient intake and milk yield, and reduced milk fat. Due to the ability of CT to inhibit the complete ruminal biohydrogenation of polyunsaturated fatty acids (PUFA), the FA composition of sulla cheese was more beneficial for consumer health compared with ryegrass cheese, having lower levels of saturated fatty acids and higher levels of PUFA and n-3 FA. The FA profile of S8 cheese was better than that of S22 cheese, as it was higher in branched-chain FA, monounsaturated FA, PUFA, rumenic acid (c9,t11-C18:2), and had a greater health-promoting index. The effect of short grazing time on sulla was attributed to major inhibition of PUFA biohydrogenating ruminal bacteria, presumably stimulated by the higher accumulation of sulla CT in the rumen, which is related to a higher intake rate over a shorter eating time. Thus, grazing sulla improved the performance of ewes, thereby increasing, especially with short grazing time, the nutritional properties of cheese fat.

The effects of different milking intervals and milking times per day in jennet milk production.

In their first 150 days of lactation, nine Ragusana jennets were investigated at the 'Istituto Sperimentale Zootecnico per la Sicilia' (ISZS) in Palermo, to study the effects of different milking typologies on milk production. The jennets were kept in a paddock and were fed hay ad libitum and concentrate (3.5 kg jennet/day). From post-foaling day 21, every 3 weeks individual milk amounts were recorded, and individual milk samples were collected and analyzed for the main qualitative parameters. The compared theses were: two daily milking times with 6- and 3-h intervals; and two, three and eight daily milking times with 3-h interval. The jennets were manually milked. The foals were separated from the jennets at 0800 h, and after the last milking the foals were housed with the jennets. During the day with eight milkings, the milk yield from the jennets was fed to their respective foals, through bottles. The 6-h milking interval produced more milk (+19%) per session than the 3-h interval (P 0.01). The fat content per session, with the eight-time milking frequency (P 0.001), was greater than the others. For each milking typology, the lactation stage had a similar effect on almost all the considered variables. When observing the eight-milking times, the fat content (%) increased from 1100 to 0500 h (P 0.001). The milk yield and the fat percentage produced by two-, three- and eight-milking times were positively correlated.

Jennet milk production during the lactation in a Sicilian farming system.

In Italy, the interest for jennet milk production has recently developed. An 18-month-long experiment was carried out on a jennet farm near Milo (CT), where 24 jennets, which derived from the Ragusana breed, were tested for milk yield and composition over an entire lactation period. The jennets were fed with hay and concentrate in a large paddock. From the 28th post-foaling day to the end of the lactation, the jennets were machine-milked twice a day with an in-between milking interval of 5 h. The milk amount from each jennet was recorded every 3 weeks and individual samples were collected and analyzed for fat, protein, casein, non-proteic nitrogen, lactose and somatic cell count. This study showed that jennets at Sicilian latitudes are not seasonal polyestrous. The daily milk yield, the length of lactation and the milk characteristics varied depending on the foaling season. The total average milk production was 490 ± 36 kg in 295 ± 12 post-foaling days, considering two milking records per day. During the lactation, milk yield decreased constantly from 1.98 to 1.28 kg/jennet per day. When looking at the jennet milk quality during lactation, the percentage of fat and protein decreased, while the lactose percentage increased, according to a tendency apparently unique for equines when compared to the ruminants. When looking at the productive season, spring generally gave the best qualitative and quantitative results. Based on these results, jennet milk yield and quality could be improved; furthermore, jennet milk production may turn out to be a profitable business.