Performance of F 1 Piglets of Sows Fed Fermented and Enzyme-Supplemented Cassava Peel Meal Based Diets

The performance of F 1 piglets fed fermented or enzyme-supplemented cassava peels was investigated. Peels from freshly harvested cassava were fermented for four days, sun-dried for 3-5 days, then milled. The cassava peel meal (CPM) replaced maize in grower and finisher diets in T 1 (control), T 2 (fermented CPM) and T 3 (fermented CPM + maxigrain R enzyme) in a completely randomized design. The diets were served at 4% of live body weights daily to 27 Largewhite x Duroc weaner-gilts, aged 8 weeks and weighing 10.61±0.27 kg. The piglets suckled until mid-lactation, then shared finishing diets with the sows in addition. Data was analyzed with one-way ANOVA on SPSS. Average litter sizes, average birth weights, average weaning body weights and mortality rates had no significant (p>0.05) differences. Average daily body weight gains differed significantly (p<0.05) 155.24±0.09g (T 1 ) and 159.29±0.15g (T 3 ) compared to 146.67±0.11g (T 2 ). Fermented cassava peels with or without enzyme supplementation has no deleterious effect on the performance of F 1 piglets.


Experimental site
The experiment was carried out at the piggery unit of the Teaching and Research Farm at the Federal College of Animal Health and Production Technology, Moor Plantation, Ibadan, Oyo State, Nigeria. Ibadan is geographically located at latitude 7° 22 ' 39 '' N and longitude 3° 54 ' 21 '' E and falls within the tropical rainforest wet and dry climate, with a lengthy wet season. It has mean total rainfall of 1420.06 mm, mean maximum and minimum temperatures of 26.46 °C and 21.42 °C respectively and relative humidity of 74.55%.

Source of ingredients and feed formulation
Fresh cassava peels for this experiment was sourced from Orile-Ilegun; an industrial layout in Ibadan, Oyo State, Nigeria. The maxigrain R enzyme was sourced from the open market with the following constituents: Amylase, xylanase, Beta-glucanase, cellulase, pectinase, protease, phytase and lipase. Four processing methods were carried out on cassava peels to determine the process that would reduce hydrogen cyanide glycoside most, improve crude protein content and be more practicable by the rural farmers. Such processing method (fermentation) was used to treat the cassava peels for onward compounding of the experimental diets thus: T1 = Conventional maize-based diet (control). T2 = T1 with the maize component (40%) replaced with fermented cassava peels. T3 = T1 with the maize component (40%) replaced with fermented cassava peels supplemented with maxigrain R enzyme. The dietary composition of the experimental grower and finisher rations are presented in Tables 1 and 2.

Experimental animals, design, management and duration
A group of 27 Large white x Duroc female weaner pigs aged 8 weeks and weighing 10.61±0.27 kg each, with good body condition, conformation and at least six pairs of teats, were used for this experiment. Measurement and recording of their body weights were carried out using weighing balance and were allotted to the above treatments using completely randomized design. The piglets were allocated to three treatment groups, each replicated thrice. They were closely observed for deformity and other aberrations that could render them unfit for the experiment and replacements were made in such eventuality. Prophylactic administration against endo-and ectoparasites were done using ivomec R (ivermectin) subcutaneous injection at the dose of 1 ml/33 kg body weight. There was also intramuscular administration of long acting oxytetracycline injection at the dose rate of 1 ml/10 kg body weight, which was repeated after 72 hours to help eliminate possible pathogenic microbes that were still under incubation. Grower diet (Table 1) was offered daily at 4% of their body weight (Santiago & Tegbe, 1987;Onyimonyi, 2002). The grower diets were given for the first eleven weeks after which they were replaced with finisher diet (Table 2) till the end of the experiment. Clean drinking water sourced from a borehole in the farm was supplied ad libitum. After farrowing, the primiparous sows were maintained on finisher diet (Table 2). The sows received 2.5 kg of feed daily and additional 0.2 kg of feed for every piglet farrowed (Miller, 2001). The piglets ate from the sows' rations (finisher) at about the mid-lactation and continued till the piglets were weaned at 6 weeks of age.

Data collection
Birth weights were taken at birth using weighing balance, and recorded for analysis. Litter size at birth was also taken for each sow and treatment groups. Mean piglet body weight gain were measured till weaning, particularly mean piglet weights at mid-lactation and weaning, litter size at weaning and mortality rate were also recorded. The weights were taken fortnightly till weaning at 6 weeks of age.

Statistical analysis
All data were subjected to analysis of variance for completely randomized design. Significant differences between means were separated using Duncan's Multiple Range Test (Duncan, 1955). Table 3 shows the performance of F1 piglets farrowed by sows fed fermented and enzyme-supplemented cassava peel meal diets. There were no significant (p>0.05) differences among the treatments with respect to the average birth weight, weaning age and the average final body weights. There was however, significant (p<0.05) difference when T1 and T3 were compared to T2 with respect to the total and daily body weight gains. There were no significant (p>0.05) differences between T1 and T3. The mid-lactation (21 st day) body weights had no significant (p>0.05) difference among the treatment groups. The mortality rates were significantly different (p<0.05) across the treatment groups with T2 having more cases than T1 whereas T3 recorded the least number of cases.

Litter sizes
The average litter sizes of 7.33±0.06 piglets (T1), 6.00±0.03 piglets (T2) and 6.33±0.08 piglets (T3) are more than 5.3 piglets reported by Motaleb et al. (2014). The T1 result was similar to 7.33±3.4 piglets/litter for Sinha et al. (2015). This range of 6 -7.33 piglets per litter is also similar to 7.47 piglets/litter reported by (Orheurata, 2000) but slightly differed from 8.17 piglets/litter reported by (Omeke, 1990) and 7.67±0.33 -8.67±0.33 piglets/litter observed by (Abonyi, 2011). Generally, the mean litter size in this study was lower than 12 piglets reported by Cole & Foxcroft, (1982) in domesticated sows and 12.2 piglets reported by (Halina et al., 1993) as well as 12.00±0.24 reported by (Iheukwumere et al., 2008). This variation could be due to feeding system (restricted), breed of pigs, parity and feed composition. The smaller mean litter size for treatments fed CPM-based diets (T2 and T3) than the control (T1) was apparently due to lower metabolizable energy and crude protein levels in these diets. Numerically, the enzyme-supplemented CPM-based diet (T3) showed marginal superiority over the CPMbased diet only (T2) possibly due to effect of enzyme. Milligan et al., (2002) and Damgaard et al. (2003) indicated that parity influences birth weight and generally, sows in first parity have lower birth weight and litter size than in subsequent parities.

Birth weights
The average birth weights of 1.12±0.04 kg (T1), 1.02±0.06 kg (T2) and 1.23±0.03 kg (T3) were similar to 1.11 kg and 1.27 kg obtained by (Purabi et al., 2013) for crossbred and Hampshire pigs respectively as well as 1.03±0.13 -1.24±0.08 kg reported by (Abonyi, 2011) but differed from 1.44 kg obtained by (Purabi et al., 2013) for Duroc. Similarly, the birth weights as recorded by (Sharma, et al., 1990;Omeke, 1990;Nath, 1993;Singh, 1994) and (Abonyi, 2011) in half-breeds of indigenous and Large White x Yorkshire were also in good agreement with the present findings. However, (Johnson & Omtvedt, 1973) and (Stewart & Drewry, 1983) reported a heavier average birth weight of 1.406±0.065 kg in Duroc. In contrast, (Pluske et al., 2005) reported birth weights of 1.83kg and 1.32 kg for heavy and light breeds of pigs respectively. In the same vein, (Hossain et al., 2011) reported a contradicting birth weight of 1.72 kg, likewise (Dejan et al., 2007) who got 1.71 kg for intermediate breed and 2.40 kg for heavy breed. The highest average birth weight showcased by pigs on enzymesupplemented diet (T3) over control (T1) and CPM-based diet (T2) could be due to effect of maxigrain R enzyme on the utilization of feed ingredients (particularly fermented cassava peels) as well as the effect of fermentation on the CPM that helped to reduce the HCN content below detrimental level. Studies have reported improved performance when exogenous enzymes are used in chicken (Zyla et al., 2000;Onyango et al., 2005;Silverside et al., 2006) and pigs (Young et al., 1993;Yi et al., 1996;Adeola et al., 1998;Matsui et al., 2000;Omogbenigun et al., 2004;Jendza et al., 2005;Cowieson & Adeola, 2005). The addition of digestibility-improving enzymes to feed can improve nutrient bio-availability and absorption, and thereby enhance the value of the feed as a source of energy, protein and other nutrients (Ullmann's, 2003;Schäfer et al., 2007;Bedford & Gary, 2010). Enzymes are mostly used when the dietary ingredients contain relatively higher amount of fiber (Bedford, 2000) and to break down the phytate molecule that binds phosphorus and some other mineral elements in plant-based feedstuffs (McDonald et al., 2001;Fuller, 2004).

Daily body weight gain
The average daily body weight gains of 155.24±0.09 g (T1), 146.67±0.11 g (T2) and 159.29±0.15 g (T3) showed no significant difference (p>0.05) between T1 and T3 but with T2 (p<0.05). The piglets on enzyme-supplemented CPM diets performed best possibly due to enzyme effect. This can be corroborated by the finding of Omogbenigun et al. (2004) who reported improvement in average daily gain of piglets receiving enzymesupplemented diets. Olukosi et al., (2007) also found improvement in broilers fed enzymes cocktail. The weight gains in this study were heavier than the 105.35 g daily weight gain obtained by (Akdag & Muglali, 2008) while some authors had reported mean values better than this present study (Shon et al., 1994;Nessmith et al., 1997;Angulo & Cubilo, 1998;Lauridsen & Danielsen, 2004;Straub et al., 2005;Pluske et al., 2005;Dejan et al., 2007;Václavková et al., 2012). The possible reasons for lower average daily gains could be environmental temperature, type of feed/ingredients, genetic make-up, breed and sex. Besides, type of feeding regimen (restricted) had effect. It can also be attributed to limiting nutrients (Kidd et al., 2001;Café et al., 2002) as portrayed by the lowest daily weight gain of T2.

Weaning body weights
The average weaning body weights of 7.64±0.13 (T1), 7.18±0.17 kg (T2) and 7.92±0.15 kg (T3) were similar to 7.67 kg and 7.32 kg reported for crossbreed (Hampshire x Duroc) (Dejan et al., 2007;Purabi et al., 2013) but heavier than 4.24 kg reported by (Akdag, 2003). The results were however less than 8.9 -9.7 kg obtained in previous studies (Vesseur et al., 1997;Milligan et al., 2002;Hossain et al., 2011) and much less than 8.45±0.11 -9.84±0.35 kg observed by (Abonyi, 2011) and 11 -14.20 kg obtained in other studies (Bruininx et al., 2001;Mota et al., 2002;Bates et al., 2003;Straub et al., 2005). The difference in weaning body weights could be attributed to the effect of the enzyme on the digestion and absorption of nutrients in respect of T3 that showed superiority over T2 and T1. The litter size differential could also be a contributing factor to differences in the average final body (weaning) weights. The relatively similar weaning weights also suggested that all the experimental diets were good and that there was no detrimental effect of HCN from CPM possibly due to fermentation (T2) and maxigrain R enzyme-supplementation (T3). Additionally, the control (T1) performed best because of the nutritional advantage (metabolizable energy and crude protein) it had over others. Other factors that could have limited the growth potential of suckling piglets include teat position (Zschorlich & Ritter, 1984a;Zschorlich & Ritter, 1984b;Puppe et al., 1993), milk composition and percentage milk protein (Noblet & Etienne, 1989) and establishment of lactation and successful nursing (Valros et al., 2002). The non-significant difference (p>0.05) in the final body (weaning) weights among the treatment piglets could also align with the findings of some authors that there was no improvement in performance of pigs given exogenous feed enzymes. Thacker et al. (1991) and (Inborr et al., 1993) observed no improvement in performance of pigs fed rye-or barley-based diets supplemented with xylanase. Officer (1995) reported no growth improvement as a result of enzyme supplementation in weanling pigs receiving wheat-SBM diet. Thacker et al. (1988) similarly reported no effect of an enzyme mixture that had β-glucanase, pentosanase, cellulase, amylase and pectinase on barleybased diets fed to 80 kg pigs. However, the numerical difference between pigs on maxigrain R enzyme supplementation and other pigs could be attributed to effect of enzyme supplementation. Omogbenigun et al., (2004) reported improvement in average daily gain of piglets that received enzyme supplemented diets. In addition, several studies have shown improvement of growth performance of pigs after the use of phytase (Nasi, 1990;Cromwell et al., 1993;Adeola et al., 1998). William (2003) also reviewed numerous studies showing that weights at birth and one week of age are correlated to subsequent performance. This assertion has been exonerated by this experiment when the initial weights were compared to the final (weaning) weights since (Rehfeldt & Kuhn, 2006) showed that piglets with lower body weights at birth grow slower.