Morning versus afternoon cutting time of Berseem clover (Trifolium alexandrinum L.) affects feed intake, milk yield and composition in Girgentana goats.

Twenty lactating Girgentana goats were used to evaluate the effect of morning v. afternoon cutting time of Berseem clover (Trifolium alexandrinum L.) on feed intake, milk yield and milk composition. Goats were randomly divided into two groups of ten animals, receiving 10 kg of fresh Berseem clover cut at 9.00 (AM group) or 16.00 (PM group), respectively; 500 g of concentrate was given individually to goats before offering forage. Feed intake increased (P<0·01) in the PM group (30·5 v. 25·3 g dry matter/kg body weight), associated with the different nutrient content of diets: lower crude protein but higher dry matter, neutral detergent fibre, water soluble carbohydrates (WSC) and total fatty acids in the PM-harvested forage. Milk production, protein and casein content were higher (P<0·05) in the PM group (1415 g/d, 3·25% and 2·42% v. 1277 g/d, 3·15% and 2·33%, respectively), whereas no differences between groups were detected for milk fat, lactose or urea content. Body weight slowly decreased from the start to the end of the experiment, without differences between groups. This study showed an important milk yield responses in Girgentana goats offered afternoon-cut compared with morning-cut Berseem clover, due to a marked increase in WSC in the afternoon-cut forage.

Effect of CSN1S1 genotype and its interaction with diet energy level on milk production and quality in Girgentana goats fed ad libitum.

A study was carried out to evaluate how the energy level of the diet can affect milk production and quality in Girgentana lactating goats in relation to polymorphism at the alphas1-casein (CSN1S1) genotype locus. Twenty-seven goats, homogeneous for milk production (1.5+/-0.3 kg/d), days of lactation (90+/-10 d) and body weight (35.8+/-5.5 kg) were selected on the basis of their CSN1S1 genotype, as follows: nine goats homozygous for strong (AA) alleles, nine goats homozygous for weak alleles (FF) and nine goats heterozygous (AF). The goats were used in a 3x3 factorial arrangement of treatments, with three genotypes (AA, FF, AF) and three diets at different energy levels (100%, 65% and 30% of hay inclusion). The experiment consisted of three simultaneous 3x3 Latin squares for the three genotypes, with one square for each level of hay inclusion in the diet. All the animals were housed in individual pens. Each experimental period lasted 23 d and consisted of 15 d for adaptation and 8 d for data and sample collection, during which the goats received the scheduled diet ad libitum. The animals were fed three different diets designed to have the same crude protein content (about 15%) but different energy levels: a pelleted alfalfa hay (H100) and two feeds including 65% (H65) and 30% (H30) of alfalfa hay (respectively 1099, 1386 and 1590 kcal NE for lactation/kg DM). All the diets were ground and pelleted (6 mm diameter). AA goats were more productive than AF and FF goats (respectively: 1419 v. 1145 and 1014 g/d; P=0.002). Indeed the interaction energy levelxgenotype was significant (P=0.018): in fact AA goats showed their milk increase only when fed with concentrates. Differences in protein and in casein levels between the three genotypes were in line with results expected from the different allele contribution to alphas1-casein synthesis. Milk urea levels were significantly lower in AA goats compared with AF and FF genotypes (respectively 32.7 v. 40.4 and 40.4 mg/dl; P=0.049) and significantly lower when goats were fed with 65H and 30H diets than with 100H diet (respectively 37.4 and 34.3 v. 41.7 mg/dl; P<0.001). Indeed, a significant interaction genotypexdiet (P=0.043) occurred for milk urea, which was significantly lower in AA goats but only when fed with concentrates (65H and 30H). Blood concentrations of energy indicators (glucose, non-esterified fatty acids and beta-hydroxybutyric acid) were not influenced by genotype. The results confirm that strong alleles are associated with a greater efficiency of feed utilization and seem to show that a high energy level of the diet can further improve this efficiency.

Diet selection and milk production and composition in Girgentana goats with different alpha s1-casein genotype.

In goats, alpha s1-casein polymorphism is related to different rates of protein synthesis. Two genetic variants, A and F, have been identified as strong and weak alleles based on a production of 3.5 and 0.45 g/l of alpha s1-casein per allele. The aim of the trial was to test whether goats can select their diet as a function of their genetic aptitude to produce milk at different casein levels and whether this selection can influence milk production or composition. Two groups of 8 animals, homozygous for strong (AA) or weak (FF) alleles were housed in individual pens. Using a manger subdivided into five separate containers, the goats were offered daily for 3 weeks: 1.5 kg of alfalfa pelleted hay, 0.7 kg of whole barley, 0.7 kg of whole maize, 0.7 kg of whole faba bean and 0.7 kg of pelleted sunflower cake. Total dry matter intake was similar between groups and resulted in nutrient inputs much higher than requirements. On average, goats selected 86% of maize plus barley and only 46% of faba bean plus sunflower. Indeed, AA goats selected less faba bean compared with FF goats (37.2 v. 56.7% of the available amount; P=0.01); during week 2 and week 3 they significantly increased maize selection (respectively for week 2 and week 3: 94.9 and 99.1% v. 85.3 and 87.3%) thus increasing the ratio between the high-energy feeds and the high-protein feeds (2.41 v. 1.81, P=0.023). As for true protein, the high soluble fraction (B1) and the indigestible fraction (C) were lower in the diet selected by AA goats (respectively in AA and FF groups: B1, 7.85 v. 9.23% CP, P<0.01; C, 6.07 v. 6.30% CP, P<0.001); these diet characteristics can be associated with lower losses of protein. Milk production, being similar in AA and FF groups when goats were fed with a mixed diet, significantly increased in AA group, when free-choice feeding was given (mean productions: 1198 v. 800 g/d, P<0.01). Casein content was higher in AA group than in FF group (2.70 v. 2.40%, P<0.01) whereas milk urea was higher in FF group (59.7 v. 48.8 mg/dl, P<0.01). In conclusion, when the animals were free to select their diet, their higher genetic aptitude to produce casein seemed to adjust their energy and protein dietary input in qualitative terms, thus leading to an increase in milk production and a decrease in milk urea. These results seem to demonstrate that interactions probably occurred between genetic polymorphism at the alpha s1-casein locus, diet selection and the efficiency of nutrient transformation into milk.

Allabogdanite, the high-pressure polymorph of (Fe,Ni)2P, a stishovite-grade indicator of impact processes in the Fe-Ni-P system.

Allabogdanite, (Fe,Ni)2P, is the only known natural high-pressure phase reported in the Fe-Ni-P system. The mineral, which was previously described from a single meteorite, the Onello iron, is now discovered in the Santa Catharina and Barbianello nickel-rich ataxites. The occurrence of allabogdanite in Santa Catharina, one of the largest and well-studied meteorites, suggests that this mineral is more common than was believed. The formation of allabogdanite-bearing phosphide assemblages in a given meteorite provides evidence that it experienced peak pressure of at least 8 GPa at a temperature above 800 °C. Since the pressure-temperature stability parameters of allabogdanite fall within the margins of the stishovite (rutile-type SiO2) stability area, the former can be employed as a convenient stishovite-grade indicator of significant impact events experienced by iron and stony-iron meteorites and their parent bodies.

Effect of morning vs. afternoon grazing on intramuscular fatty acid composition in lamb.

The aim of this study was to assess whether different grazing management affect animal performance and meat fatty acid composition. Thirty-five lambs were divided into three groups: 12 lambs grazed from 9 am to 5 pm (8 h group); 11 lambs grazed from 9 am to 1 pm (4hAM group) and 12 lambs grazed from 1 pm to 5 pm (4hPM group). The trial was conducted over 72 days. The 8 h lambs had greater DMI (P<0.0005) and final body weight (P<0.05) than the 4hPM and 4hAM lambs while carcass weight was not different between the three groups. The meat of the 4hPM lambs contained greater (P<0.05) percentages of polyunsaturated fatty acids, C18:2 cis-9 trans-11 and lower saturated fatty acids and C18:0 than the meat of the 8 h and 4hAM lambs. It is concluded that allowing lambs to graze during the afternoon rather than during 8 h does not compromise the carcass yield and results in a healthier meat fatty acid profile.

The volatile compounds in lamb fat are affected by the time of grazing.

This study was designed to assess whether different grazing managements affect the appearance of organic volatile compounds (VOC) in lamb fat. Forty-two lambs were divided into four groups: 9 lambs were restricted in stall and fed concentrate (S group); 12 lambs grazed from 9 am to 5 pm (8h group); 10 lambs grazed from 9 am to 1 pm (4 hAM group) and 11 lambs grazed from 1 pm to 5 pm (4 hPM group). After 72 days on feed the animals were slaughtered and the perirenal fat subjected to SPME-GC/MS analysis of VOC; the data were analyzed by stepwise discriminant analysis. The 6-methyl-2-heptanone and furanone, 2,5-dimethyl, 4-hydroxy-3(2H) allowed discrimination between the 4 hAM and the 4 hPM animals. These are the first results indicating that the time of the day in which the animals are allowed to graze affects the appearance of VOC in lamb fat.

Milk quality as affected by grazing time of day in Mediterranean goats.

We evaluated the effect of grazing time of day on goat milk chemical composition, renneting properties and milk fatty acid profile in a Mediterranean grazing system. Sixteen lactating Girgentana goats were divided into two experimental groups and housed in individual pens, where they received 500 g/d of barley grain. For 5 weeks the two groups were left to graze in two fenced plots on a ryegrass sward as follows: morning group (AM), from 9.00 to 13.00; afternoon group (PM), from 12.00 to 16.00. In selected herbage, water-soluble carbohydrates (WSC) increased in the afternoon (204 v. 174 g/kg dry matter, DM; P=0.01), whereas crude protein (CP) and linolenic acid decreased (respectively, 16.7 v. 19.8% DM; P<0.01 and 26.8 v. 30.4 g/kg DM; P<0.01). Pasture dry matter intake (DMI) was significantly higher in the afternoon (0.82 v. 0.75 kg/d; P=0.026). Fat corrected milk production (FCM), milk fat and lactose content were not affected by treatment, whereas protein and titrable acidity ( degrees SH) increased in the PM group (respectively 3.56 v. 3.42%; P=0.01; 3.55 v. 3.22 degrees SH/50 ml; P=0.01). In contrast, milk urea content was significantly higher in the AM group (381 v. 358 mg/l; P=0.037). The results seem to indicate that an improvement in ruminal efficiency might be obtained by shifting grazing time from morning to afternoon, as a consequence of a more balanced ratio between nitrogenous compounds and sugars. Indeed, the higher linolenic acid and the lower conjugated linoleic acid (CLA) (respectively 1.02 v. 0.90, P=0.037; 0.71 v. 0.81% of total fatty acids, P=0.022) in the milk of goats grazing in the afternoon seem to indicate a reduced biohydrogenation activity in the PM group.