Effects of dietary L-carnitine and pomegranate seed pulp on the quality and milk production and rumen parameters of lactating goats

Using agricultural and food industry by-products can reduce nutritional cost. Among by-products, pomegranate seed pulp (PSP) can be used in animal nutrition. To improve the using of the oil in pomegranate seed which most of it is long chain fatty acids, L-carnitine can be utilized. It is effective on long chain fatty acid oxidation for increasing milk production efficiency. This study was designed to investigate the effects of PSP containing unsaturated fatty acids with L-carnitine, on the quantity and quality of milk from Mahabadi lactating goats as well as their rumen activity.
Thirty-two Mahabadi lactating goats with days in milk of 45±6, daily milk production of 1.05±0.20 kg, the average age of three years, 39.8±4.1 kg weight with one sucker kid. Goats were assigned to four groups with eight animals per group. The goats were used in a 2 × 2 factorial arrangement with two levels of 0 and 10% PSP and 0 and 300 parts per millions of L-carnitine per kg of dry matter for six weeks. The experimental diets included: diet without PSP and L-carnitine (control group), diet with 10 percent of PSP without L-carnitine (PSP group), and diet without PSP but with 300 parts per million per kg of dry matter L-carnitin (LC group), and diet with 10 percent PSP and 300 parts per million per kg DM L-carnitine (PSP group), respectively. According to feeding goats individually, goat feed intake were recorded daily. Milk production for every goat was measured two times per day using a milking machine. Sampling from the rumen fluid was done on the last day of the final week of the experiment just three hours after morning feeding with using the esophagus tube connected to vacuum pump. Data analysis was performed using SAS 9.1 (2002) software, and MIXED procedures.
The results of this experiment showed that the addition of PSP and L-carnitine to the diet had no effect on final weight, total weight, average daily gain and dry matter intake, and the change in conversion factor was insignificant. Milk production (grams per day) were not different between treatments, but on the basis of 4 percent fat corrected milk, fat percentage, fat content and fat / protein ratio significantly increased by addition of PSP (P0.05). Also, PSP and L-carnitine did not have any significant effects on molar ratio of the all volatile fatty acids and acetate to propionate ratio, but interaction between PSP and L-carnitine administration increased acetate molar ratio and reduced the isovaletaye and butyrate molar ratio (P The results showed that the addition of the PSP and L-carnitine to the diet improved the quality of the goat milk. Although simultaneous use of PSP and L-carnitine showed no significant effect on milk production, also interaction of PSP and L-carnitine on rumen activity led to increase in acetate production. According to the results, it can be concluded that PSP can be utilized in animal nutrition as a cheap by-product to improve production and composition of goat milk and L-carnitin also can be used as an effective supplement on dietary fat and better supply of energy available in nutrition of dairy goat.