Feeding value of hays of tropical forage legumes in pigs: Vigna unguiculata, Psophocarpus scandens, Pueraria phaseoloides and Stylosanthes guianensis

Re-domestication of feral pigs in Martinique: first results of growing-finishing trials to test meat consumption and consumers' perceptions

In Martinique, pig production satisfies less than 20% of demand for pork, with traditional pig farming and wild pig hunting covering only a small proportion. This study has three parts: (i) for the first time, it analyses the performance of domesticated descendants of Creole feral pigs of Martinique based on a 29-day finishing test on two farms (A vs. B) with the same fibre-rich diet on a total of 40 pigs; (ii) it evaluates consumers' tastes based on a sensorial test by an untrained panel of 61 consumers who tasted pork prepared as a fricassee from either farm A or farm B; and (iii) evaluates willingness to pay (WTP) for Creole pork products and of the design of a future niche market. The average daily gain (ADG) of the finishing pigs was higher on farm A than on farm B (256 vs. 100 g/d, P < 0.001) resulting in a higher hot carcass weight on farm A than farm B (41.3 vs. 33.5 kg, P < 0.01), and better hot carcass yield on farm B than farm A (74.0 vs 68.8 %, P < 0.01). In the sensorial test, the consumers gave a higher score to the meat originating from the youngest pigs (Farm B), especially scores for tenderness and juiciness (+0.94 and +0.55 points, P < 0.05 and P=0.10, respectively). The 61 respondents were willing to pay more for processed products (sausage, pâté, ham) than for fresh meat. They considered that Creole pork has a better taste and is of better quality than industrial meats originating from mainstream genotypes. According to the majority of respondents, Creole pork should be rich in intra-muscular fat (100% of respondents) and low in inter-muscular fat (60% of respondents). Based on the survey, the main desirable future for Martinique's Creole pig production correspond to a low-carbon system with feed based on local resources, with on-farm slaughtering and short-distance sales (direct-to-consumer farm gate sale, sale at the butcher's or at the pig cooperative).

Effects of Sucrose, Glucose and Molasses on Fermentation Quality and Bacterial Community of Stylo Silage

To better understand the mechanism underlying water-soluble carbohydrates (WSC)-regulated silage fermentation, the bacterial community and fermentation quality of stylo (Stylosanthes guianensis) ensiled without (sterile distilled water) (CK) or with 10 g/kg sucrose (S), 10 g/kg glucose (G), and 10 g/kg molasses (M) were investigated. Each treatment was ensiled in three plastic bag silos for 30 days. The DM of stylo was 301.0 g/kg (fresh matter basis), while the contents of CP, WSC, NDF and ADF were 104.9, 12.3, 510.4 and 407.6 g/kg (dry matter basis), respectively. The bacterial community was characterized by using 16Sr DNA sequencing technology. The addition of WSC significantly altered both fermentation quality and the bacterial community of stylo silage. The additive treatment resulted in higher lactic acid (17.2 vs. 67.0 g/kgDM), lower pH (4.68 vs. 4.46), and lower acetic acid (37.0 vs. 28.9 g/kgDM) compared with the control. In addition, no propionic acid and butyric acid were detected in the additive treatment groups. These results indicated that WSC additives helped to produce greater quality stylo silage. Meanwhile, the Shannon index was higher, and the Simpson index was lower in the WSC additive-treated groups compared with the control, indicating that WSC improved microbial diversity. Furthermore, WSC treatments increased the abundance of acid-producing bacteria Megamonas and Bacteroides, decreased the abundance of Weissella, and inhibited the growth of the undesirable Enterobacter. Our results confirmed that sucrose, glucose and molasses have similar beneficial effects on both bacterial community and silage fermentation of stylo. Molasses was recommended to be used in stylo silage for economic benefit and resource utilization.

Dynamics of shearing force and its correlations with chemical compositions and in vitro dry matter digestibility of stylo (Stylosanthes guianensis) stem

Objective

The study explored the dynamics of shearing force and its correlation with chemical compositions and in vitro dry matter digestibility (IVDMD) of stylo.

Methods

The shearing force, diameter, linear density, chemical composition, and IVDMD of different height stylo stem were investigated. Linear regression analysis was done to determine the relationships between the shearing force and cut height, diameter, chemical composition, or IVDMD.

Results

The results showed that shearing force of stylo stem increased with plant height increasing and the crude protein (CP) content and IVDMD decreased but fiber content increased over time, resulting in decreased forage value. In addition, tall stem had greater shearing force than short stem. Moreover, shearing force is positively correlated with stem diameter, linear density and fiber fraction, but negatively correlated with CP content and IVDMD.

Conclusion

Overall, shearing force is an indicator more direct, easier and faster to measure than chemical composition and digestibility for evaluation of forage nutritive value related to animal performance. Therefore, it can be used to evaluate the nutritive value of stylo.

Silage fermentation and ruminal degradation of stylo prepared with lactic acid bacteria and cellulase

In order to improve the silage fermentation of stylo (Stylosanthes guianensis) in tropical areas, stylo silages were prepared with commercial additives Lactobacillus plantarum Chikuso-1 (CH1), L. rhamnasus Snow Lact L (SN), Acremonium cellulase (CE) and their combination as SN+CE or CH1 + CE, and the fermentation quality, chemical composition and ruminal degradation of these silages were studied. Stylo silages treated with lactic acid bacteria (LAB) or cellulase, the pH value and NH₃ -N ⁄ total-N were significantly (P < 0.05) decreased while the ruminal degradability of dry matter (DM), crude protein (CP), neutral detergent fiber (aNDFom) and acid detergent fiber (ADFom) were significantly (P < 0.05) increased compared to control. Compared to LAB or cellulase-treated silages, the DM, CP contents and relative feed value (RFV), and the ruminal degradability in LAB plus cellulase-treated silages were significantly (P < 0.05) higher, but the aNDFom content was significantly (P < 0.05) lower. CH1 + CE treatment was more effective in silage fermentation and ruminal degradation than SN+CE treatment. The results confirmed that LAB or LAB plus cellulase treatment could improve the fermentation quality, chemical composition and ruminal degradation of stylo silage. Moreover, the combined treatment with LAB and cellulase may have beneficial synergistic effects on ruminal degradation.

Nutritive value of three tropical forage legumes and their influence on growth performance, carcass traits and organ weights of pigs

The effects of tropical forage legumes on feed intake, growth performance and carcass traits were investigated in 16 groups of two Large White × Duroc pigs. The diets consisted of a commercial corn-soybean meal diet as the basal diet and three forage-supplemented diets. Four groups of control pigs received daily 4 % of body weight of the basal diet, and 12 groups of experimental pigs were fed the basal diet at 3.2 % of body weight completed with fresh leaves of one of the three forage legumes (Psophocarpus scandens, Stylosanthes guianensis and Vigna unguiculata) ad libitum. The study lasted 90 days. The in vitro digestion and fermentation of the forage legumes were also determined. The in vitro digestible energy content of the legumes was between 0.72 and 0.77 that of the basal diet (14.4 MJ/kg dry matter (DM)). V . unguiculata was the most digestible forage legume expected for crude protein digestibility. Feeding forage legumes lowered the dry matter intake by 4.5 to 9.6 % (P < 0.05), final body weight (P = 0.013), slaughter weight, average daily gain and hot carcass weight (P < 0.05) without affecting the feed conversion ratio (FCR), dressing percentage and back fat thickness. In conclusion, using forage to feed pig could be interesting in pig smallholder production with limited access to concentrate, as FCR was not significantly affected.