Protein supplementation of rations based o whey for growing pigs

Abstract

Fifty-six individually penned Large White x Landrace pigs (28 females and 28 castrated males), growing from 50 to 120 lb live weight, were used to evaluate the response to variation (12 to 18%) in the protein content of meal mixtures fed at the constant rate of either 1 t or 2t lb/pig/day as supplements to lactic casein whey.On average, gilts grew significantly faster than castrates (p<0.05), utilised the whey consumed more efficiently (p<0.05), and produced leaner carcasses.Pigs fed the 2t lb daily meal allowance grew I 0% fa~ter than those fed only 1 t lb meal per day (p<0.OO5), but did not differ significantly in carcass characteristics.Increases in the protein content of meal supplements fed at the rate of 1 t lb/day had no significant effect on either rate of gain at any stage from 50 to 120 lb live weight, or on carcass quality, but resulted in a significant linear improvement in the efficiency of whey utilisation over the period of 50 to 85 lb live weight (p<0.05). At the 2t lb/day level of meal feeding, increases in meal protein content resulted in a linear improvement in both rate of gain (p<O.OI) and efficiency of whey utilisation (p<O.05) up to 85 lb live weight, but not thereafter. Changes in indices of carcass composition suggested a corresponding increase in carcass lean content.Regression analysis of the growth data from the first 7 weeks of the experiment disclosed a highly significant sex X treatment interaction (p<O.005). Whereas gilts outgained castrates on the lower protein diets, due to the positive and negative trends in the growth rate of castrates and gilts respectively in response to increases in protein intake, the position was reversed at the higher levels of protein.

Protein supplementation of rations based on whey for growing pigs

“…The results therefore support information demonstrating close correlation between TDN and ADE (Maynard 1953;Swift 1957;Crampton 1957;Robinson 1965). Consequently the differences evident in Table 2 between the ADE % of diets containing various proportions of barley meal, BMP, and whey are in accordance with the respective TDN contents of t~ese three foods (Carr and Dunkin 1969) and indicate that energy proVIded in the form of whey is digested with comparable efficiency when consumed in varying amounts by the young growing pig, at least within the range involved in this experiment.…”

“…An experiment has been reported which was designed to assess the response of pigs growing from 50 to 120 lb live weight, in terms of rate of gain, efficiency of food utilisation, and carcass quality, to protein supplementation of diets based on lactic casein whey (Carr and Dunkin 1969). This is referred to as the first experiment in the ensuing report.…”