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.

Analysis of weaning-induced stress in Saanen goat kids.

In young ruminants' life, weaning often coincides with a period of growth stasis and poor welfare. The present study aimed at evaluating the effect of coping with the new diet on behavioural and haematological stress indicators in goat kids subjected to a commonly adopted weaning practice. Immediately after birth, male Saanen goat kids were divided into two groups: MILK and WMIX. All were fed colostrum for the first 3 days and then goat milk to the age of 29 days. After that, MILK kids continued to receive milk, while the WMIX kids underwent weaning and were completely weaned by day 48. Animal behaviour was recorded daily. From day 23-50, blood samples were taken weekly and analysed for indicators of stress and immune function. No abnormal behaviour, such as injurious behaviours or stereotypies, was observed in either of the experimental groups throughout the experimental period. During the last week, fasting plasma cortisol level was significantly lower, whereas plasma activity of both alanine aminotransferase (ALT) and aspartate aminotransferase (AST) was significantly higher in WMIX kids, in relation to the MILK ones. Anyway, data were within the normal physiological range and no difference was observed neither in plasma haptoglobin, ceruloplasmin, albumin and antithrombin III, nor in plasma immunoglobulin A and G, at any time, signalling no stressful condition. Therefore, differences observed in cortisol, ALT and AST could be the consequence of the metabolic changes that occur during the transition from pre-ruminant to ruminant state. The gradual weaning at 48 days of age did not result in any stressful condition and had no negative effect on weight gain. Results suggest that parameters commonly adopted to provide information on animal stress, such as cortisol and aminotransferase activity, can vary in relation to the physiological status of the animals and may bias stress assessment.

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.

Ghrelin, insulin and pancreatic activity in the peri-weaning period of goat kids.

Two groups of 3-day-old Saanen goat kids (MILK and WMIX) were studied in order to investigate the effect of weaning on plasma ghrelin and insulin and on pancreatic activity. MILK kids received goat milk to age 50 days; WMIX kids were initially fed milk but started weaning at 30 days and were completely weaned by 48 days. Dry matter intake and body weights were recorded, and plasma samples were analysed for metabolites, ghrelin, insulin, leptin and α-amylase. At 50 days, all the animals were slaughtered, pancreas samples were analysed for α-amylase, zymogen, DNA and ribosomal capacity (RNA/zymogen). Seven days after the beginning of the weaning program, dry matter intake in the WMIX group began to decrease in relation to the MILK group. Nonetheless, body weight did not differ throughout the study period. Weaning significantly decreased plasma levels of glucose, amino acids, urea and insulin, but increased creatinine and ghrelin. In weaning kids ghrelin secretion may help minimize the negative consequences of the new diet on dry matter intake. Pancreatic zymogen and ribosomal capacity did not differ between the groups, whereas pancreatic amylase activity was over three times higher in MILK than WMIX kids even though the former had no dietary starch. This finding could be a consequence of lower pancreatic secretion of amylase in the MILK group due to the lack of dietary starch, resulting in pancreatic accumulation, but could also be due to higher plasma insulin in the MILK group, suggesting a role for insulin in the functional development of the pancreas in weaning goats.

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 IGFI 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.