Fabia Rosi

Effect of dietary conjugated linoleic acid supplementation in sows on performance and immunoglobulin concentration in piglets

Conjugated linoleic acid isomers may affect the onset and severity of several diseases, including tumors, atherogenesis, and obesity. They may also modulate the immune response. However, little information regarding the most advantageous duration of CLA supplementation is available. The purpose of this study was to determine whether the length of dietary CLA supplementation of a sow affects growth, immune components, and metabolic and hormonal factors in lactating sows and piglets. Gestating sows were fed a control (0%) and a 0.5% CLA-supplemented diet beginning 7 d before parturition and ending 7 d postpartum (T1), or until weaning (T2; 7 sows per treatment). Colostrum and sow and piglet blood samples were collected for the determination of serum metabolite concentrations and immunoglobulin titer. Piglet BW at weaning were greater (P < 0.05) in the CLA groups compared with the control. Dietary CLA supplementation increased (P < 0.05) serum thyroxine concentration in sows, but serum insulin, glucose, NEFA, IGF-I, and leptin concentrations were not affected by CLA supplementation. Colostral IgG, IgA, and IgM titers were greater in sows fed CLA than in control sows (P < 0.05). At weaning (21 d), serum IgG titer of the piglets was greater (P < 0.05) in the T1 and T2 groups than the control group, but at 13 d postweaning, a difference (P < 0.05) was observed between the control and T2 group. The results from this study indicate potential beneficial effects of 0.5% dietary CLA supplementation from 7 d before parturition until 7 d postpartum in improving BW at weaning and immune components in piglets.

Effects of Cocoa Husk Feeding on the Composition of Swine Intestinal Microbiota

A two-diet/two-period change over experiment was performed to investigate the effects of cocoa husks, as a source of dietary fiber and polyphenols, on pig intestinal microbial composition. Six pigs were fed a conventional cereal-based diet or a diet obtained by substitution of 7.5% of the conventional diet with cocoa husks for 3 weeks. Experimental diets were isoproteic and isoenergetic. At the end of each 3 week testing period, samples of fresh feces were collected and analyzed for microbial composition by fluorescence in situ hybridization. Cocoa husks did not affect feed intake, weight gain, and feed efficiency. Analysis of fecal microbial populations, grouped by phyla, showed a decrease of Firmicutes and an increase of Bacteroidetes in cocoa husk-fed pigs. Particularly, cocoa husks reduced fecal populations of the Lactobacillus-Enterococcus group and Clostridium histolyticum and increased the Bacteroides-Prevotella group and Faecalibacterium prausnitzii, suggesting a potential for cocoa husks in the improvement of intestinal microbial balance.

Leptin in milk and plasma of dairy asses

Abstract Milk and plasma leptin levels have been studied in dairy asses machine milked according to two different routines: 20 pregnant, pluriparous asses, were divided into two groups subjected, every 28 d for 150 d, to two consecutive milkings carried out at different intervals, i.e. 20 vs. 4 hours interval, respectively for group A and group B. During the study, the declining total milk obtained by machine milking was unaffected by the different milking strategies; body condition score of asses as well did not vary between the groups. Different milking intervals did not significantly influence skimmed milk leptin content neither plasma leptin level. Moreover, we did not find significant variation in plasma leptin neither correlation with BCS, indicating that in donkey pregnancy inhibits the cross talk between hypothalamus and adipose tissue.

Trend analysis of plasma insulin level around parturition in relation to parity in Saanen goats

The present study investigated the effect of parity on plasma insulin level around parturition in Saanen goats. On d -14, -7, 0, 3, 7, 10, and 14 from parturition, plasma glucose, NEFA, free AA, cortisol, and insulin concentrations were analyzed in 10 primiparous and 10 multiparous goats. At parturition, BW of primiparous goats was about 75% of that of multiparous ones (P < 0.001) and then their milk production was lower than that of multiparous ones (P < 0.001). At parturition, glucose increased (P < 0.01) in both primiparous and multiparous goats and then decreased (P < 0.01) on d 3 of lactation, remaining higher (P < 0.01) in primiparous than multiparous goats until the end of the study period. In both groups, free AA decreased (P < 0.01) at parturition, returning to prepartum levels (P < 0.01) on d 3 of lactation without difference between groups. Only in multiparous goats, plasma NEFA increased at parturition (P < 0.01), returning to prepartum levels on d 14 (P < 0.01). Changes in glucose and AA could have been caused by cortisol, which increased (P < 0.01) at parturition in both primiparous and multiparous goats, returning to prepartum levels (P < 0.01) on d 7 of lactation, without difference between the parity groups. In multiparous goats, insulin decreased soon after parturition (P < 0.05), remaining at low levels until the end of the study period, whereas in primiparous goats, insulin did not vary until d 14 of lactation, when it decreased (P < 0.05) also in this group. Therefore, between d 3 and 14 of lactation, insulin was higher in primiparous than multiparous goats (P < 0.05). Only in primiparous goats, at kidding, insulin was negatively correlated to BW (P < 0.01), and after parturition it was negatively correlated with milk yield (P < 0.05) and plasma NEFA (P < 0.05). We hypothesize that higher insulin levels in primiparous Saanen goats, which are still immature at their first breeding season, acted to limit both the mobilization of bodily reserves and the capture of nutrients by the lactating mammary gland, thus providing nutrients for their own physical and physiological development.

EFFECTS OF RECOMBINANT BOVINE SOMATOTROPIN (RBST) ON PRODUCTIVE AND PHYSIOLOGICAL-PARAMETERS RELATED TO DAIRY-COW WELFARE

Two trials have been carried out to evaluate welfare implications or rbST treatment in dairy cows. 1st trial: effects of rbST and F/C ratio on milk production traits, reproductive, metabolic and endocrine parameters were examined. Forty Italian Holstein Friesians (70 d post-partum) were divided into 4 groups: low concentrate (LC); high concentrate (HC); LC+rbST; HC=rbST. LC and HC groups were fed 0.35 and 0.50 kg concentrate/kg of milk yield >18kg. rbST (640 mg/cow) was injected at 28 d intervals for 112 d. 2nd trial: 4 dairy cows (191 d post-partum), each fitted with rumen cannula, were used in a crossover design to examine influence of rbST (640 mg/28 d) on rumen parameters. There was an average increase of 19% in 4% FCM for rbST versus control cows (24.6 vs. 21.0; 18.33 vs. 15.15 kg/d). Milk composition was unaffected except for a decrease (P<0.01) in milk protein percentage of LC+rbST group (2.87% vs. 2.94%). Days open were unaffected by rbST. Seven days post-injection, rbST significantly increased plasma GH, glucose, NEFA, triglyceride, phospholipid, insulin, somatostatin, lowered plasma urea and did not affect plasma total protein, albumin and total cholesterol. Somatotropin did not influence ruminal pH (6.08 vs. 6.10), concentrations of ruminal ammonia (8.28 mg/100 ml vs. 10.48 mg/100 ml), trotal ruminal VFA (111.73 mmol/1 vs. 114.09 mmol/1) and their molar proportion and liquid passage rate (14%/h).

Influence of high levels of beet pulp in the diet on endocrine/metabolic traits, slaughter dressing percentage, and ham quality in Italian heavy pigs

Abstract Seventy two Landrace x Large White barrows were divided into three groups and fed different diets: a control traditional diet based on cereals (C) and two with 15 or 30% dried sugar beet pulp (BP15 and BP30, respectively). Animals weighed 106 kg at start and 167 kg at the end of the experiment. Feeding was restricted (2.5 kg DM/head, on average). The aim of the present experiment was to investigate the influence of high levels of beet pulp in the diet of fattening heavy pigs on some endocrine/metabolic traits, on the slaughter dressing percentage and on some parameters related to meat quality, composition and on the ham quality, after 14 months of seasoning. During the experimental period, jugular vein blood samples were collected from C and BP30-fed pigs and plasma was analysed for several metabolic traits. BP30 diet initially increased the plasma glucose level and decreased free amino acids (P<0.05), but this difference disappeared at the end of the experimental period, when insulin level was decreased (P=0.06) by beet pulp administration. During the entire period, 30% beet pulp diet increased total protein and albumin levels (P<0.001) and decreased urea (P<0.05) without affecting plasma leptin. At slaughter, pigs fed BP30 diet were lighter (P<0.001) and with a lower dressing percentage (P<0.001) in comparison with the other two treatments. Pigs fed BP30 diet also had lower ham and loin weights (P<0.05) (but similar ham and loin percentages) and higher liver weight (P<0.05), liver/carcass ratio (P<0.001), gastrointestinal-tract weight (P<0.001) and gastrointestinal-tract/carcass ratio (P<0.001). Pigs fed C diet had a higher dressing percentage in comparison with pigs fed BP15 diet (P<0.01), but no other significant difference was found between pigs fed diets C and BP15. At slaughter, liver samples were taken from C and BP30-fed pigs in order to evaluate the effect of the diet on liver composition. BP30 diet increased dry liver weight (P<0.05) and liver fat content (P<0.01). The iodine value and the fatty acid composition of the backfat revealed no significant difference between pigs fed the control diet and those fed the high fibre diets. Finally, considering the economic importance of ham production, the characteristics of the seasoned hams were evaluated. No difference was observed on ham quality. In conclusion, feeding a diet with a high percentage of dried sugar beet pulp alters protein and energy metabolism and slaughter parameters, without affecting the quality of the seasoned ham.

Endocrine and metabolic traits in goat kids around weaning

Abstract Eleven Saanen kids, three days after birth, were divided into two groups: WEAN and MILK. All kids were fed goat milk until the 5th week of age, when the WEAN group began a weaning protocol. MILK group continued to receive goat milk for the entire experimental period, while WEAN group was weaned at 47 days of age. Starting from the 3rd week of age, body weight was recorded and blood samples were taken weekly, before the first meal of the day. Plasma was analysed for glucose, total protein, free aminoacid, insulin, leptin and ghrelin. Weaning did not affect plasma levels of total protein and leptin, but decreased plasma glucose and free aminoacid, and increased ghrelin concentration. Moreover, weaning decreased plasma insulin level more than three times. This result was probably the consequence of the lower concentration of plasma glucose of the WEAN group, but the effect could be enforced by the milk-borne insulin ingested by the MILK kids with the diet. Goat milk contains peptides that can pass across the intestinal epithelium and enter the systemic circulation, suggesting a possible role in accomplishing the immature ability of suckling animals to produce hormones and growth factors.

Diet influences the content of bioactive peptides in goat milk

Leptin, insulin, ghrelin, and IGF-I are circulating peptide hormones concerned with energy homeostasis and the regulation of GH axis. They are present in human milk, and are thought to promote neonatal development. The aim of the present study was to detect these substances in goat milk and determine whether their levels can be modified by changing the macronutrient content of the lactating animals’ diet. Sixteen Saanen goats in mid-lactation were divided into two balanced groups, one given a diet containing 17% starch (LS) and the other a diet of 33% starch (HS). Eighty days later, leptin, insulin, ghrelin, and IGF-I were determined by human radioimmunoassay kits in plasma before and after feeding, and in sonicated milk centrifuged to remove fat from morning and evening milking. The HS diet was associated with higher plasma and milk insulin and IGF-I, and plasma ghrelin. Leptin, insulin, and ghrelin in milk were two-three times higher than in plasma; milk IGF-I was only 5–20% of plasma level. Plasma insulin correlated positively with plasma IGF-I; morning milk IGF-I and insulin correlated positively with morning plasma levels. These findings demonstrate that human immuno-activities of bioactive peptides are present in goat milk, and also that levels of insulin and IGF-I in milk can be altered by changing the macronutrient content of the diet. Further research is required to determine whether these substances can be transferred from the milk to suckling animals and humans, and whether they have biological activity in such animals.

Leptin and puberty in goat

Riassunto Leptina e pubertà nella capra. Ventiquattro capre di razza Serrana (7,93±0,24 kg, 93±2,6 giorni di età) sono state suddivise in 3 gruppi alimentati per 11 mesi con fieno ad libitum e differenti quantità di concentrato (30, 50 e 70% della sostanza secca ingerita) fino alla pubertà. I tre gruppi hanno ingerito la stessa quantità di sostanza secca. Il gruppo alimentato con la dieta a maggior apporto di concentrato ha mostrato un anticipo di 30 giorni nella comparsa della pubertà, presentando un maggiore deposito adiposo sottocutaneo ed un maggiore peso vivo rispetto agli altri due gruppi. I livelli di leptina plasmatica sono aumentati significativamente nei 3 mesi prima della pubertà senza mostrare differenze significative tra i 3 gruppi sperimentali, sebbene siano risultati correlati (P<0,01) al peso corporeo ed allo spessore del pannicolo adiposo.

Cocoa husks in diets of Italian heavy pigs

The aim of the present study was to evaluate the effect of cocoa husks feeding on liver composition of the Italian heavy pig. Cocoa husks are by-products derived from chocolate production and have a high content of proteins, lipids, and NDF. Cocoa husks are also rich in antioxidants, polyphenols in particular. Eight finishing pigs were divided into 2 groups: control group fed a traditional diet, based on cereals, and treatment group fed a diet obtained by substitution of 10% of the control diet with coarsely ground cocoa husks. The trial was conducted during the hot season and lasted 6 wk, at the end of which all the pigs were slaughtered. Cocoa husks diet reduced dry matter intake (P < 0.01) and energy intake (P < 0.01) but neither body weight nor backfat thickness was affected by cocoa husks diet. Treatment did not influence carcass weight and hot dressing percentage but reduced liver weight (P < 0.05), liver dry matter percentage (P < 0.01), DNA (P = 0.01), and glycogen content (P = 0.01). By contrast, cocoa husks increased liver ether extract (P = 0.05) without affecting cholesterol content. Liver weight loss, reduction of protein synthesis, and a shift toward glycogen use instead of fat oxidation are considered metabolic strategies to reduce heat production under hot conditions. It is possible, therefore, that cocoa husks feeding promoted the process of acclimation because pigs needed less feeding to reach similar body and carcass weight as control pigs.