[show abstract][hide abstract] ABSTRACT: Polymorphism at the αS1-casein locus (CSN1S1) in goats influences several milk production traits. Milk from goats carrying strong alleles, which are associated with high αS1-casein (αS1-CN) synthesis, has higher fat and casein contents, longer coagulation time and higher curd firmness than milk from goats with weak alleles linked to low αS1-CN content. Nutrition also affects these milk properties; therefore, it is important to better understand the interaction between dietary characteristics and the CSN1S1 genotype in goats. This study aimed to investigate the effect of fresh forage based diet or energy supplement on feeding behavior, milk production, and metabolic and hormonal parameters of Girgentana goats with different genotypes at CSN1S1 loci. From a group of goats genotyped by PCR at the DNA level, 12 were selected because they had the same genotype for αS2-CN, β-CN, and κ-CN but a different genotype for αS1-CN: 6 were homozygous for strong alleles at the CSN1S1 loci (AA) and 6 were heterozygous for a weak allele (AF). Goats of each genotype were allocated to 3 subgroups and fed 3 diets ad libitum in a 3 × 3 Latin square design. The diets were sulla (Hedysarum coronarium L.) fresh forage, sulla fresh forage plus 800 g/d of barley meal (SFB), and mixed hay plus 800 g/d of barley meal (MHB). Diet had a stronger effect than CSN1S1 genotype. The SFB diet led to the highest energy intake, dry matter (DM) digestibility, and milk yield. The fresh forage diets (SFF and SFB) increased DM and crude protein (CP) intake, CP digestibility, and milk CN compared with the MHB diet. The diets supplemented with energy (SFB, MHB) reduced milk fat and urea, improved CP utilization for casein synthesis, and limited body fat mobilization, in accordance with a lower level of nonesterified fatty acids and higher levels of glucose and IGF-1. With regard to CSN1S1 genotype, AA goats showed higher CP digestibility and lower free thyroxine hormone and cholesterol levels than AF goats. Significant diet × genotype interactions indicated how AA goats, compared with AF goats, showed higher DM digestibility and milk yield when fed the SFB diet, which had more energy. A reduction in free triiodothyronine hormone occurred in AF goats fed the MHB diet, whereas no differences were observed in AA goats. These results demonstrate how goats with a higher capacity for αS1-CN synthesis exhibit more efficient energy and protein utilization, evident at the digestive level, and better productive responses to high-nutrition diets.
Journal of Dairy Science 04/2013; 96(4):2107–2117. · 2.57 Impact Factor
[show abstract][hide abstract] ABSTRACT: Caciocavallo Palermitano is a typical stretched-curd cheese that has been produced over the centuries in Sicily according to traditional cheesemaking technology and using raw milk from autochthonous cow breeds reared at pasture. The objective of this experiment was to evaluate the effects of the farming system and processing technology on the characteristics of Caciocavallo Palermitano cheese, with particular regard to the fatty acid profile. The farming system was either extensive, using autochthonous cows fed a pasture-based diet, or intensive, with specialized dairy cow breeds fed mainly hay and concentrate. The cheese-processing technology was either artisanal, using traditional wooden tools and endemic lactic bacteria, or advanced, using modern steel equipment and selected lactic bacteria. Twelve Caciocavallo Palermitano cheeses, 3 from each of the 4 experimental theses (2 farming systems × 2 cheesemaking technologies), were obtained and aged for 1, 30, 60, and 120 d. Milk of origin and cheeses were analyzed for the main chemical and rheological parameters. Fatty acids were methylated in lyophilized cheese and analyzed by gas chromatography. Sensory analysis was carried out by trained panelists. The PROC GLM of SAS 9.1.2 (SAS Institute Inc., Cary, NY) was used for the statistical analysis. The physical, chemical, and sensory characteristics of Caciocavallo Palermitano cheese were influenced more by the farming system than by the cheesemaking technology. Compared with cheese produced through intensive farming, cheese from extensive farming was richer in polyunsaturated, n-3, and odd- and branched-chain fatty acids, as well as in conjugated linoleic acid (cis-9,trans-11 C18:2), with accompanying improved human health benefits. The cheesemaking technology produced variation in the evolution of proteolysis during aging, due presumably to the different active microflora, which influenced the sensory profile of the resulting cheese. Indeed, cheese produced by artisanal manufacturing was described as less "bitter" and more "piquant" than cheese produced through the advanced process.
Journal of Dairy Science 11/2012; · 2.57 Impact Factor
[show abstract][hide abstract] ABSTRACT: The nutritional effects of sulla (Hedysarum coronarium L.) forage containing condensed tannins (CT) on growth of lambs, and carcass and meat quality were investigated. Thirty-two male Comisana lambs aged 100 ± 8 days weighing 19.0 ± 2.8 kg were fed fresh forage of sulla or CT-free annual ryegrass (Lolium multiflorum Lam. subsp. Wersterwoldicum) for 49 days until slaughter; in addition, each lamb was supplied with 200 g/days of concentrate. Eight lambs per diet had been previously treated with anthelmintic drugs to remove nematode parasites. Measurements of BW and feed intake, and counts of faecal nematode eggs were made. Carcass parameters were recorded after slaughter, and tissue components of the hind leg were determined. Longissimus dorsi meat was evaluated for pH, colour, thawing and cooking losses, Warner-Bratzler shear force, chemical composition and sensory properties based on triangle tests. Relative to ryegrass-fed lambs, sulla-fed lambs had significantly greater dry matter (DM) and protein intake, a more favourable feed conversion ratio, and superior growth rate, final BW at 150 days of age, carcass weight, yield and fatness. These results were attributed to the high protein and non-structural carbohydrate content of sulla, and also to the moderate CT content of sulla (16.7 and 20.3 g/kg of DM in offered and consumed sulla forage, respectively). Anthelmintic treatment did not affect lamb growth, as the level of parasitic infection (initial and final) was low. The physical, chemical and sensory properties of the lamb meat were not influenced by diet.
[show abstract][hide abstract] ABSTRACT: In order to verify the effect of the introduction of concentrates without GMO risk and at low aflatoxin risk in the diet of grazing milk ewes on the quanti-qualitative production of meat of their milk-fed light lambs, two trials were carried out - in Sicily, on 32 Comisana lambs, slaughtered at 49±4 days (trial 1); and in Sardinia, on 28 Sarda lambs, slaughtered at 31±4 days(trial 2) - comparing the following grazing dams’ feeding regimes: High stocking rate + Organic (barley – tickbean or pea) Concentrate (HO); High stocking rate + Conventional (maize-soybean) Concentrate (HC); Low stocking rate + Organic Concentrate (LO); Low stocking rate + Conventional Concentrate (LC). Lamb performances, carcass quality, meat colour and lipid content were not modified by dam’s feeding regimen. However, significant differences were observed in the fatty acid (FA) composition of the intramuscular fat of the older suckling lambs of trial 1. The main variation concerned n-3 polyunsaturated FAs and conjugated linoleic acids.
[show abstract][hide abstract] ABSTRACT: A total of 24 Girgentana goats was divided into 3 homogeneous groups grazing a sulla monoculture under stocking rate of 30, 50 or 70 goats/ha (LSR, MSR and HSR). Available biomass, herbage selected by goats and milk yield were measured and sampled. The DM intake of goats and its botanic composition and digestibility were assessed by the n-alkane method. Grazing at HSR was suspended 18 d before MSR and LSR (35 vs. 53 d), due to the low biomass availability. Over the first 35 d of grazing, the HSR reduced height and availability of herbage. The herbage intake and milk yield of goats increased from HSR to LSR, without relevant changes in milk quality. During all grazing period (53 d), the higher grazing pressure led to a lower total milk yield per goat, whereas the HSR produced the highest daily and total milk amount per ha.
[show abstract][hide abstract] ABSTRACT: Synchronization methods are used to obtain higher fertility when artificial insemination (AI) is applied to lactating rabbit does. The most common methods are eCG administration or temporary doe-litter separation. Nevertheless, drawbacks have been reported, such as negative side effects of hormonal treatment in the doe and low litter growth due to absence of suckling, respectively. Recently, improved reproductive performance (without visible consequences on young rabbit growth), has been obtained by applying a 2-day controlled nursing method before AI, by allowing for a 10 min nursing of the litter 24 h of separation. The present study was undertaken to examine the pituitary (PRL, LH, FSH) and the ovarian response (follicle size and number) to those methods. A total of 442 lactating does inseminated on day 11 post-partum were distributed in three experimental groups: 2CN (closing of nest box on day 9, controlled nursing on days 10 and 11), eCG (20 IU administered on day 9 post-partum) and CONTROL (untreated). Blood samples were obtained from 10 does per group at 48, 24 and 0 h before AI, and 1h after AI. Both 2CN and eCG treatments similarly improved sexual receptivity (76.3, 77.5 and 58.2%, respectively; P<0.001) and fertility (63.1, 64.1 and 48.4%, respectively; P<0.05) in lactating does, compared to the CONTROL group. Similar plasma FSH levels in all groups of does and sampling times were observed. Due to the absence of suckling, plasma concentration of PRL on day 10 post-partum in the 2CN group was lower than in the CONTROL group (P<0.05); this endocrine change in PRL levels could explain the better reproductive performances obtained with 2CN treatment. At 1h after exogenous administration of GnRH (at the moment of AI) a high LH response was observed in all groups (P<0.001). Ovaries from 20 rabbits treated in the same way but uninseminated (2CN, n=10; eCG, n=5; CONTROL, n=5 does) were obtained on day 11 post-partum in order to check the morphometric status (weight, width and height) and to make histological and immunohistochemical studies to detect growth hormone receptor (GH-R). As a result, synchronization methods did not show any significant difference in relation to the CONTROL group. However, a small increase in the number of primary follicles was evidenced in the 2CN group with respect to the eCG group, similarly to the CONTROL group (23.0+/-3.7, 9.4+/-4.9 and 14.8+/-4.92 primary follicles, respectively; P=0.1). GH-R immunostaining-presence was more evident in the 2CN and the eCG groups, including primordial follicles and oocytes themselves. Thus, there could have been some direct effects of GH on follicular development, as described in other species. Some ovarian parameters described open new ways to study intra-ovarian mechanism of follicular development in the post-partum period of rabbit does.
[show abstract][hide abstract] ABSTRACT: To prevent the weight loss of litters, and the distress of both rabbit does and their litters due to doe-litter separation (DLS), without losing its beneficial effects on fertility, the DLS, lasting 48 h before artificial insemination (AI), was split into two periods of 24 h with a short controlled suckling.Initially, 105 does of different parity were divided into three groups. During the post partum, the free-nursing does were treated as follows: regular DLS (R-DLS), the nest-box was closed for 48 h, from days 9 to 11, before AI; split DLS (S-DLS), the nest-box was closed for 24 h and, after suckling, for other 24 h before AI; control, does had free access to the nest-box.Fertility improved (P≤0.05) in both R-DLS (60.9%) and S-DLS (59.4%) does compared to control does (44.1%). R-DLS and S-DLS does showed lower rabbit losses from days 14 to 35 (P≤0.001) and higher litter sizes at weaning (P≤0.05) than control does. Whereas the S-DLS did not affect the growth-rate and the weight of nursed rabbits until the weaning, the R-DLS reduced growth from days 9 to 14 (9.3, 13.2 and 14.0 g/day for R-DLS, S-DLS and control, respectively; P≤0.001) and the weaning weight of rabbits (732, 777, 780 g for R-DLS, S-DLS and control, respectively; P≤0.01). Productivity improved by 35.4% and 44.2% with R-DLS and S-DLS, respectively.
[show abstract][hide abstract] ABSTRACT: This experiment aimed to investigate the effects of a concentrate supplement based on barley and tickbean (BT), compared with a concentrate of maize and extruded soybean meal (MS), on milk and cheese yield and composition of ewes grazing with different stocking rates (SR). Thirty two Comisana ewes, divided into four groups, for 50 days in spring were allowed to graze plots of a mixed sward of Italian ryegrass and berseem clover with a low (LSR, 23 ewes/ha) or a high SR (HSR, 38 ewes/ha) and fed BT or MS. Herbage allowance per ewe was more than double at LSR compared to HSR (P < 0.001), and daily milk yield was 10 to 15% higher (P < 0.01) in the LSR-BT ewes than in the other groups. Milk composition, cheese yield and composition were not influenced by treatments. Curd firming time (k20) was higher (P < 0.05) for LSR-BT milk. Milk fatty acid composition of ewes fed MS, compared to BT, had a higher level of C18:0 and a lower level of C16:0 and C18:3 n-3. Milk trans-10 C18:1 and trans-13 C18:1 fatty acids were higher (P < 0.05) at HSR and with BT, while trans- 12 C18:1 was higher at LSR (P < 0.05). LSR increased (P < 0.05) the cheese content of odd and branched chain fatty acids compared to HSR. The results suggest that both concentrate type and pasture availability influenced milk and cheese composition, whereas milk yield was positively affected by the interaction LSR × BT.