Effects of Different Protein Levels on the Nitrogen Balance, Performance and Slaughtering Traits of Cinta Senese Growing Pigs

Abstract

Cinta Senese is characterized by slow growth rates, which implies different nutritional requirements compared to major pig breeds. Four different crude protein levels (120, 140, 160 and 180 g/kg on as-fed basis, denoted as CP12, CP14, CP16 and CP18) were tested to assess the optimal protein requirements of Cinta Senese pigs during the growing phase. The in vivo performance, slaughtering traits and nitrogen balance were evaluated using individual pens and metabolic crates. Increasing the protein level in feed lowered the average daily gain (from 0.76 to 0.71 kg/d), final weight (63.0 kg for CP12 versus 60.7 kg for CP16) and reduced the protein conversion efficiency (from 0.37 to 0.58). Also, protein conversion in lean protein linearly increased from CP12 (4.82) to CP18 (7.43), which implies a worsening in the protein utilization efficiency. The nitrogen balance showed higher loss of N through urine (from 0.68 g/d/kg metabolic weight for CP12 to 1.14 g/d/kg metabolic weight for CP18) as the dietary CP levels increased, and a decrease in the biological value (51.78 for CP12 versus 36.54 for CP16). The results indicated that the CP12 diet was adequate for fulfilling the Cinta Senese protein requirements during the growing phase.

Effects of Different Dietary Protein Levels on the Growth Performance, Serum Biochemical Parameters, Fecal Nitrogen, and Carcass Traits of Huanjiang Mini-Pigs

“…In the present study, dietary CP levels had a distinct effect on the carcass traits. As dietary CP levels increased, the slaughter rate of pigs during different growth stages decreased linearly, which was in agreement with the previous studies ( 24 , 40 ). Conversely, several previous studies showed that reducing the CP level by 4% based on a normal CP diet and balanced with crystalline AAs had no significant effects on the slaughter rate ( 41 , 42 ).…”

A Comparison of Stocking Methods for Pasture-Based Growing-Finishing Pig Production Systems

“…The total weight gain was similar in both grazing periods and averaged 61.5 kg pig −1 , the same weight gain figure reported for rotationally stocked pigs during 12 weeks in Uruguay [ 46 ]. The daily weight gain recorded in this study was in the range of values reported for Iberico pigs (0.74 to 0.78 kg pig d −1 ) [ 73 ] and similar to the values registered for Cinta Senese pigs (0.71 to 0.76 kg pig d −1 ) [ 67 ] or for pigs managed in a weekly rotation system (0.73 kg d −1 ) [ 59 ] but are lower than those obtained in strip grazing managed pigs (0.90 kg pig d −1 ) [ 60 ]. The forage species in the pasture has effects on weight gain.…”

“…The feed efficiency values measured in the present study were greater (+8%) in pigs from rotationally managed paddocks than for pigs continuously stocked, while the values obtained from pigs in the strip-grazing treatment were intermediate. Similar values have been registered for Cinta Senese pigs [ 67 ], while lower feed efficiency (0.23 kg kg −1 ) has been reported for grazing pigs in Uruguay [ 46 ].…”