146
Understanding the impact on performance and the costs associated with increasing gestation feed allowance to sows classified as thin body condition
The objective of this study was to determine if increased daily feed allowance during gestation leads to increased weight gain, feed costs, and improved body condition of sows. Fifty-six sows classified as thin body condition (body condition score (BCS) = 2.2 ± 0.07) were randomly allotted by gestation week (wks 5-10) and parity (2-4; 3.7 ± 0.09) to one of two daily feed allowance treatments (3.2 vs. 4.5 kg). Additionally, 24 sows (BCS = 3.4 ± 0.08; parity = 3.6 ± 0.11) considered to be in “ideal” body condition were fed 3.2 kg of feed daily and served as controls. Feed was pre-weighed and delivered to sows individually and remaining feed weights were estimated daily. Sows were individually weighed and BCS evaluated at the start (d 0) and end of study (d 30). Two experienced herds people visually scored BCS on a scale of 1 to 5 on sows individually. Data were analyzed using the MIXED procedure of SAS with sow as the experimental unit and fixed effects of daily feed allowance and gestation week. Body weight at d 0 was included as a continuous variable. For all sows, BCS improved over the 30 d period (control = 3.68, 4.5 kg/d = 2.94, 3.2 kg/d = 2.91) with the control sows maintaining a significantly higher (P < 0.0001) BCS when compared to sows that were classified thin at d 0. Overall sows fed 4.5 kg of feed daily had greater BW gain (36.9 vs. 27.7 kg; P = 0.0006) when compared to sows initially classified as thin body condition that were fed 3.2 kg daily. Furthermore, when economically evaluating the treatments, the cost per kg of gain was not significantly different ($1.08 vs. $1.09/kg gain) when feeding either 3.2 or 4.5 kg per day to sows classified as thin. However, sows on the 4.5 kg per day treatment had the greatest total feed cost per sow when compared to sows from the control group and treatment sows that were fed 3.2 kg daily ($37.36, $25.22, and $26.43, respectively; P < 0.0001). In conclusion, increasing daily feed allowance for sows classified with a thin body condition score during gestation improved gain and BCS, while not significantly increasing the feed cost per kg of gain for these animals over the 30 d trial.
Keywords: body condition, gestation feed, sows