Feeding Liquid Sweet Whey to Growing Swine

Liquid sweet whey (LSW) is the by-product resulting from the manufacture of hard cheeses. It is the liquid remaining after the cheese curds are removed. Entrepreneurial artisanal cheese plants located on the urban-fringe or associated with the rural agro-tourist areas of Michigan and other states, are too small to gain the attention of whey processors, leaving swine farmers the opportunity to access a low-cost swine feedstuff. This work was conducted to study the effects of feeding liquid sweet whey to growing pigs on growth performance and pork eating attributes. A total of 72 barrows (Yorkshire x [PIC 327], weighing 9.63 kg and 8.33 kg BW at weaning for Rep 1 and 2, respectively) were used. Six pens and 6 pigs per pen were used in each replicate. When weaned, pigs were allotted based on BW and birth litter to 1 of 2 experimental treatments: 1) Control, provision of corn soybean-diets and water in a single-space wet-dry feeder; or 2) LSW, provision of corn soybean-diets and LSW in a single-spaced, wet-dry feeder. Each feeder was fitted with a nipple drinker. No other source of liquid was provided. Pigs were fed for 98 and 103 d in Rep 1 and 2, respectively. Average daily gain did not differ between the two treatments. Daily dry feed intake was less (P < 0.01) for pigs fed LSW but they consumed an average of 9.10 kg of LSW each day, resulting in those pigs have slightly greater (P < 0.05) average daily dry matter intake. Feeding LSW resulted in slightly poorer (P < 0.05) efficiency of dry matter utilization. A triangle taste testing was completed using a sirloin chop and results indicate that consumers detected a difference (P < 0.05) between pork harvested from whey-fed pigs and those fed commercially available grain based feeds. Feeding LSW using wet-dry feeders in wean-finish production has potential to provide economic and environmental benefits for both cheese and pork production.

	Control	LSW	SE or (SD)	P - value
ADG, kg	0.88	0.86	0.019	0.50
Average daily dry feed intake, kg	1.95	1.37	0.046	< 0.01
Average daily LSW intake, kg	-	9.10	(2.83)	-
Average daily dry matter intake, kg	1.72	1.85	0.022	< 0.05
Efficiency (gain:dry matter intake)	0.515	0.471	0.0099	< 0.05