Effect of amino acid level in the pig diet during growing and early finishing on growth response during the late finishing phase of lean meat type gilts.

BACKGROUND: This experiment examined the influence of different amino acid levels during the growing and early finishing diet and the late finishing diet on growth performance and carcass quality of a lean meat type gilt. In a two by two factorial trial, 96 gilts were divided over four treatments. The two factors were (1) amino acid level in growing and early finishing and (2) amino acid level in late finishing. For the low amino acid diets we lowered the lysine, methionine, threonine and tryptophan levels by 20% and 30% in the growing and two finishing phases, respectively. RESULTS: Restricting amino acid levels in growing and early finishing led to a decreased growth rate but improved efficiency of amino acid use, which lasted into the subsequent phase. Pigs on a high amino acid diet in late finishing pigs were able to compensate to a large extent for amino acid restriction in growing and early finishing. Amino acid content in late finishing determined carcass quality. CONCLUSION: In the lean meat type gilts used in this experiment, restricting amino acid concentrations by 20% in the growing and 30% in the early finishing phase increased the growth rate and efficiency of growth in the subsequent late finishing phase. In order to obtain good carcass quality, it is crucial to provide the animals with a balanced diet during the late finishing phase.

Effect of decreasing ideal protein levels on performance results and nitrogen efficiency of growing-finishing gilts.

This study examined the effect of decreasing ideal protein concentrations on performance and nutrient efficiency. The experimental diets contained 100%, 90%, 80% or 70% of the ideal dietary protein level (Diet 100%, 90%, 80% and 70%, respectively) estimated in previous experiments with pigs of the same genetic background. The four different treatments were divided among 16 pens of six pigs each. The average initial and final body weight were 20.8 +/- 1.1 and 107 +/- 3 kg, respectively. Three-phase feeding was applied (BW 20-40 kg, 40-70 kg and 70-110 kg). The dietary ileal digestible (ID) methionine + cystine, threonine, tryptophan, isoleucine, valine, and leucine contents expressed as percent of ID lysine were 63, 72, 22, 60, 68, and > 100%, respectively. The lysine to protein ratio was kept constant at 6.8%. Between 21 and 106 kg BW the best performance was achieved on Diet 90%. Diet 70% led to significantly worse results. Although lean meat percentage did not differ, protein content of the carcass was lower on Diet 70% than on Diets 90% and 100%. Decreased protein concentrations increased crude protein efficiency and consequently decreased nitrogen excretion most at the 80% level. If protein varies together with digestible amino acid content, it can be concluded that Diet 80% may be the best choice for the environment and for profitability. If protein content stays at a fixed level, Diet 90% may be the safest choice.

Reducing nitrogen excretion and soybean meal use by feeding a lower rumen degradable protein balance and protected soybean meal to dairy cattle.

To reduce N pollution by dairy cows, two levels of rumen degradable protein balance (RDPB) and the use of protected protein sources were studied in two feeding trials. Trial 1 investigated if the effect of lowering the RDPB, at a constant DPI (digestible protein in the intestine) supply, could be compensated by using protected protein sources (formaldehyde treated (= formolated) soybean meal (FSBM) or a combination of FSBM and formolated rapeseed meal at a ratio of 60:40). Trial 2 studied if FSBM is as effective as soybean meal (SBM) at a low RDPB level. Each trial was set up as a Latin square design, with three treatments and three periods, involving 18 lactating Holstein cows. Reducing RDPB from about 150 g/d to below -40 g/d resulted in small negative effects on the milk production, independent of the protein source (protected or not). However, N excretion per kg fat and protein corrected milk (FPCM) and N efficiency were both improved. At a low RDPB level, the performance of FSBM (35.0 kg FPCM) was no better than after feeding a combination of FSBM and formolated rapeseed meal (34.7 kg FPCM). The use of FSBM (32.8 kg FPCM and 34.2% N efficiency) was as effective as SBM (32.5 kg FPCM and 34.2% N efficiency). As such, SBM use can approximately be halved by using FSBM, possibly in combination with locally produced rapeseed meal.

Feeding measures to reduce nitrogen excretion in dairy cattle.

Feeding measures with a potential to improve N efficiency in dairy cattle husbandry were studied at two levels of undegradable protein balance (OEB). In each of the two experiments, two simultaneous Latin squares were conducted, each with three treatments and three lactating Holstein cows. Decreasing the OEB of the diet improved N efficiency and resulted in lower N excretion per kg milk. To avoid a negative effect of the decreased OEB on the production results, spreading the concentrate intake (as TMR or in five meals) seemed to be most promising, although only few significant effects were found. The use of protected protein sources or the addition of clinoptilolite were not successful in improving N-efficiency. The rather well balanced mixed basal diet and the large variation between animals seem to have hampered the assessment of such significant influences.

Response of 40-70 kg barrows and gilts to increasing ideal protein concentrations in the diet.

In Belgium, crossing a hybrid dam with a Piétrain sire leads to a rather lean and meaty fattening pig type. A digestibility trial and a performance trial were carried out to determine protein needs of this pig type. Six experimental diets with increasing protein content were formulated with 0.65-1.25% apparent ileal digestible lysine. The feeds were formulated to the ideal protein composition, with lysine as the reference amino acid. Standardised and apparent digestible amino acid values of the extreme diets were measured in a digestibility trial with four gilts cannulated at the end of the ileum, with an average initial and final BW of 39.1 kg and 55.3 kg, respectively, using a protein-free feed to estimate the basal endogenous N-losses. A performance trial at 13-18 weeks of age (40-70 kg BW) was performed with barrows and gilts separately at six protein levels, balanced in lysine, threonine, methionine and tryptophan. The experiment consisted of 11 pens (of 5 animals) per treatment and per sex. Average daily gain (ADG) and feed conversion ratio (FCR) reached maximal performance within the experimental lysine range for both sexes. Based on the ADG-data for barrows and on the ADG- and FCR-data for gilts, a protein level for optimal performance corresponded with a standardised ileal digestible lysine concentration of 0.89% for barrows and of 1.07-1.09% for gilts.

Effect of seven hours intermittent suckling and flavour recognition on piglet performance.

A low feed intake during the first days after weaning is predisposing for weaning diarrhoea and weight loss. In this experiment we tried to increase the feed intake of the piglets after weaning by stimulating the solid feed intake during the last two weeks before weaning by separating them from the sows for 7 h/d. In addition, the effect of flavour recognition and the interaction of flavour recognition with intermittent suckling were tested. In two consecutive weaning rounds, sows were divided over two compartments with 7 to 10 sows each. They were assigned to one of four treatments in a two factorial design: control housing/control feed (n = 7); control housing/ flavoured feed (n = 8); intermittent suckling/control feed (n = 7); intermittent suckling/ flavoured feed (n = 9). After weaning, for each round 3 pens of 6 pigs were selected per treatment group. All these piglets received the same feed with the same flavour at the same concentration. Contrary to the expectations, intermittent suckling decreased the solid feed intake during the last two weeks before weaning. Flavour addition to the creep feed did not increase feed intake or other performance parameters before and after weaning, nor did it interact with intermittent suckling. Although after intermittent suckling pigs ate less creep feed before weaning, they did not perform worse after weaning. However, to increase feed intake after weaning, longer periods of separation might be necessary.