Effects of methionine plus cysteine inclusion on performance and body composition of liquid-fed crossbred calves fed a commercial milk replacer and no starter feed

Abstract

This experiment aimed to evaluate the effects of supplying 4 different inclusion levels of Met + Cys to crossbred liquid-fed calves on animal performance and body composition. Thirty-six Holstein-Gyr male calves were separated into 2 age groups: 16 calves, slaughtered at an age of 30 d, representing the physiological phase from 8 to 30 d, and 20 calves, slaughtered at an age of 60 d, representing the physiological phase from 30 to 60 d. At 8 d of age, the animals were randomly distributed among the experimental treatments: 4 Met + Cys inclusion levels (Met + Cys: 8.0, 8.7, 9.4, and 10.2 g/d), provided by an AA supplement added to 1.0 kg (as fed) of commercial milk replacer containing soy protein concentrate and wheat protein isolate reconstituted at 13.8% (dry matter basis). The diet was supplied without allowing leftovers and no starter feed was provided. The experimental diets were supplied without allowing orts, so that the dry matter, crude protein, and ether extract intakes were the same for all animals, independent of Met + Cys level. Total weight gain, average daily gain, gain composition, and body composition were evaluated for both age groups separately. Digestibility of organic matter, crude protein, and ether extract was lower for 8 to 30 d than for 30 to 60 d. The effect of Met + Cys levels on the digestibility of nutrients was not observed; there also was no significant interaction between physiological phase and Met + Cys levels. For the 8 to 30 d group, no responses in performance were observed according to the different Met + Cys levels, which indicates that 8.0 g/d of Met + Cys met the requirements for this physiological phase. The 30 to 60 d group responded positively to higher Met + Cys inclusion in the diet. In conclusion, an optimal Met + Cys dietary level to ensure best performance and protein gain ranges from 8.41 to 9.81 g/d.

Effects of linseed oil and rumen undegradable protein:rumen degradable protein ratio on performance of Holstein dairy calves

“…Another way is to replace a feedstuff containing a high RUP level such as maize gluten meal or fishmeal instead of the protein source in the basal diet (36) . Gathering together the results obtained in previous works (19,20,34,35,37) , discrepancies among studies for the effects of RUP:RDP ratios on dairy calves' growth rate responses might be attributed to the differences in the source and level of RUP feeding and different amino acid profiles of experimental feedstuffs included in the starter diet which could influence dairy calves' performance.…”

Effects of different types of zinc supplement on the growth, incidence of diarrhea, immune function, and rectal microbiota of newborn dairy calves

“…Methionine is one of the main limiting AA for ruminant growth (Hill et al, 2008) and plays an important role in metabolism. About 52% of Met is metabolized by intestinal lumen cells, where it is converted to cysteine (Wu et al, 1998), which promotes performance (Jankowski et al, 2014;Chagas et al, 2018). However, the individual and joint actions of Met and zinc in Zn-Met require further investigations.…”

Determination of macromineral requirements for preweaned dairy calves in tropical conditions

“…The database used to estimate macromineral requirements (Ca, P, K, Mg, and Na) comprised 5 studies conducted at Federal University of Viçosa (Jolomba, 2015;Silva et al, 2015;Rodrigues et al, 2016;Dias et al, 2017;Chagas et al, 2018) totaling 210 calves. In each study, individual information of each mineral (Ca, P, K, Mg, and Na) was collected for mineral intake (MI; g/d), retained mineral (RM; g/d), and mineral body content (h ; Tables 1 and 2).…”