Effects of Dietary Cashew Nut Testa as an Alternative to Wheat Bran in Swine Diet

Abstract

Effects of Dietary Cashew Nut Testa as an Alternative to Wheat Bran in Swine Diet

These experiments were conducted to evaluate the 1) effects of dietary cashew nut testa (CNT) as an alternative ingredient on growth performance and carcass quality of growing-finishing pigs, 2) effects of dietary CNT levels as an alternative of wheat bran in gestating sow and 3) effect of dietary CNT supplementation levels on nutrient digestibility in gestating sows.

Experiments I. Effects of dietary cashew nut testa as an alternative ingredient on growth performance and carcass quality of growing-finishing pigs.

This experiment was performed to assess the effect of different level of CNT in growing-finishing pig diets on growth performance, blood profile and carcass characteristics. A total of 160 crossbred pigs ([Landrace X Yorkshire] X Duroc) with an average body weight of 28.05 ± 8.47kg were used for 12 weeks feeding trial for grower and finisher in Seoul National University Experimental Farm. Pigs were allotted to one of four treatments with 4 replicates and 10 pigs per pen in randomized completely block (RCB) design based on sex and initial body weight. Treatments were: 1] CON: corn and SBM based diets which met requirements of NRC (1998) + 0% CNT, 2] C2: CON + 2% CNT, 3] C4: CON + 4% CNT, and 4] C6: CON + 6% CNT. There was no significant difference in average daily gain (ADG) among treatments, but ADFI showed linear response in growingⅠ(P=0.02) and finishingⅠphase (P=0.04), respectively. Feed efficiency in growingⅠphase showed significant linear difference and quadratic response as the amount of CNT increased (linear, P<0.01

quadratic, P=0.02). Total cholesterol concentration was decreased by addition of CNT during the whole experimental period. There were no significant differences in BUN, creatinine, insulin and glucose concentration during 12 weeks of experiment. No significant differences were observed in WHC, cooking loss and shear force of pork as the level of CNT supplementation. In economic efficiency, feed costs per gain during whole experiment (0-12 week) were lower in the order of C6, C2, CON and C4. Consequently, this experiment demonstrated that addition of 6% CNT can be supplemented in growing-finishing pig diet without any negative effects on growth performance, pork quality and feed cost.

Experiments II. Effects of dietary cashew nut testa levels as an alternative of wheat bran in gestating sow

This experiment was performed to determine the effects of dietary cashew nut testa (CNT) instead of wheat bran as an ingredient on reproductive performance, litter performance, milk composition, and blood profiles of sows in gestation. The experiment was started when sows were on their 35 days of pregnancy with an initial average body weight (BW) of 211.53 ± 3.52 kg. 40 multiparous sows (Yorkshire × Landrace) were allotted to one of four treatments based on BW, backfat thickness and parity in 10 replicates. Treatments were as followed: 1] C0: corn-SBM based diet, 2] C2: basal diet with 2% CNT, 3] C4: basal diet with 4% CNT, and 4] C6: basal diet with 6% CNT. Experimental diet (gestating diet) contained 3,265 kcal of ME/kg, 12.90% crude protein, 0.74% lysine, 0.20% methionine, 0.90% calcium, and 0.70% total phosphorus, respectively. Other nutrients were met or exceeded NRC requirement (1998). There were no significant differences in body weight, body weight change, backfat thickness, and backfat thickness changes of gestating sows at 35 day, 70 day, and 110 day, 24 hour after parturition and 21day of lactation among treatments. But the body weight change of lactating sows tended to decrease linearly (P=0.09) and the daily feed intake of sows tended to increase (P=0.09) during lactation. The quadratic response was observed in weaning to estrus interval (WEI) after weaning (P=0.02), and the treatment added 2% of CNT (C2) showed the shortest WEI among treatments. Total born alive piglets were 10% higher in C2 and 12.5% higher in C4 treatment, respectively compared to control treatment. Litter birth weight (P = 0.04) and piglet weight (P = 0.01) after cross-fostering were reduced by addition of CNT in diet. However, litter weight gain and piglet weight gain had no significant differences in 21 day of lactation. In milk composition, the percentage of fat (p = 0.03), lactose (p = 0.02) and total solid (p = 0.03) in 24 h postpartum showed a quadratic correlation with the increasing CNT level during gestation while lactation progressed showed no correlation. Along with the increasing CNT level in diets, insulin concentration at 70 d of gestation was reduced linearly (p = 0.03). Consequently, there were no negative effects of addition of 4% CNT instead of wheat bran in gestating sow. Consequently, 4% of CNT supplementation instead of wheat bran in gestating sows diet could be acceptable as an alternative ingredient.

Experiments III. Effect of dietary cashew nut testa supplementation levels on nutrient digestibility in gestating sows This experiment was conducted to evaluate the effect of cashew nut testa (CNT) supplementation levels on nutrient digestibility and its availability in gestating sows. A total of 20 gestating sows (Yorkshire × Landrace, at d 90 of gestation) with initial BW of 252.61 ± 24.69 kg, BF thickness (P2 position) of 23.4 mm and average parity 6.5 was used in a digestibility trial. Sows were allotted to one of four treatments in a completely randomized design (CRD) by their body weight, backfat thickness and their parity. Treatments were: 1] C0: corn-SBM based diet, 2] C2: basal diet with 2% CNT, 3] C4: basal diet with 4% CNT, and 4] C6: basal diet with 6% CNT. Experimental diet (gestating diet) contained 3,265 kcal of ME/kg, 12.90% crude protein, 0.74% lysine, 0.20% methionine, 0.90% calcium, and 0.70% total phosphorus, respectively. Other nutrients were met or exceeded NRC requirement (1998). There were no significant differences in BW and BF thickness at initial and final days of trial by dietary CNT level. Increasing the supplementation of CNT level decreased digestibility of dry matter (linear, P=0.03), crude protein (linear, P=0.04), ether extract (linear, P=0.05) in gestating sows. Also, crude fiber, ADF and NDF digestibility tended to decease linearly by increase of dietary CNT level (linear, P=0.07

linear, P=0.06, linear, P=0.02, respectively). These results indicated that nutrients digestibility was lowered as dietary CNT level was increased, but body weight and backfat thickness of sows were not affected by dietary CNT during gestation.