The effect of fishmeal supplementation of a straw-based diet on growth and calorimetric efficiency of growth in heifers

Abstract

Thirty-two 160 kg dairy heifers were used to measure the effects of increasing dietary protein content on growth and heat production. A basal diet containing (g/kg) 550 sodium hydroxide-treated straw, 220 barley, 220 sugarbeet pulp and 10 urea was offered with 0,76 and 152 g fishmeal/kg dry matter of the basal diet (FO, F1 and F2 levels respectively). The three diets were each given at two levels of feeding (low, L; high, H): 57.6 g/d per kg metabolic body-weight (Wo7') for the LFO diet and 747 g/d per kg Wo7' for the HFO diet. Apparent digestibility of the diets increased in response to the addition of fishmeal. Mean dry matter digestibility values were 0.67, 0.67, 0.69, 0.66, 0.68 and 069 and those for acid-detergent fibre digestibility were 0.60,0.63,066,0.58,060 and 0.65 for diets LFO, LF1, LF2, HFO, HFl and HF2 respectively. Nitrogen retention increased in response to both fishmeal and feeding level. Live-weight gains were 170, 296,434 g/d for the LFO, LFl and LF2 diets and 468,651 and 710 g/d for the HFO, HF1 and HF2 diets respectively. There were significant effects of increasing the plane of feeding and the level of fishmeal in the diet on live-weight gain. Dietary effects on live-weight gains were accompanied by increases in mean energy retention of 23,45,82,94,160 and 152 kJ/d per kg WO" for diets LFO, LFl, LF2, HFO, H F l and HF2 respectively, but no definite evidence was obtained that dietary supplementation with fishmeal modified the efficiency of utilization of metabolizable energy for growth.

Frequency of concentrate supplementation for cattle fed barley straw. 1. Effect on voluntary intake, ruminal straw disappearance, apparent digestibility and heat production

“…The improvement in digestibility is consistent with the 10% increase in ruminal degradability of straw which we observed at 24 h when straw was incubated in situ in steers consuming the high-protein diets (Table 3). Our results therefore confirm those of researchers such as Ortigues et al (1990), Beaty et al (1994 and Fike et al (1995) who measured improvements in the digestibility of straw associated with protein supplementation.…”

Effects of a high-protein, low-energy diet in finishing lambs: 1. Feed intake, estimated nutrient uptake, and levels of plasma metabolites and metabolic hormones

“…Ortigues et al (1990) and Kabré and Petit (1994) also found that fish meal supplementation significantly increased digestibility of a medium quality roughage under restricted intake levels. However, our values are considerably greater than the 43% reported by NRC (1985) for barley straw.…”

“…Plasma concentrations of insulin like growth factor 1 (IGF-I; ng/ml) in lambs receiving the three diets CON = concentrate diet ad libitum, STR = straw ad libitum, SFM = straw ad libitum plus 150 g/ d fish meal, over the duration of study. Ortigues et al (1990) found elevated levels of plasma glucose in heifers limit-fed a straw-based diet when supplemented with high levels of fish meal. However, when the base diet was fed at high levels, plasma glucose levels were highest at low levels of fish meal supplementation.…”

“…Given the genetic heterogeneity of the animals in our experiment, the estimation of degree of maturity based on a breed specific standard growth curve would not have been possible; this situation appears to be the norm in the literature. Ortigues et al (1990) measured comparable effects of fish meal supplementation on BUN levels in heifers under a similar regimen. Galbraith et al (1997) found a difference in BUN between fish meal supplemented and unsupplemented treatments similar to that observed in the present study.…”

Whole-body fuel selection in ruminants: nutrient supply and utilization by major tissues

“…Overall, the responses predicted here do not clarify the small and variable effects of CP on the efficiency of energy utilization by the growing ruminants (Ortigues et al 1990). …”