Eighty Holstein calves born in a dairy farm with good management practices were used to evaluate the effect of treatments on calf-starter intake, growth rate, and incidence of gastrointestinal disorders during the first 30 days of birth. Calves were fed during first 6-h of birth with 4L of with unheated (RAW) or pasteurized (PST, pasteurized during 60 min at 60 ˚C) colostrum (IgG>50 g/L), followed by supplementation with or without symbiotic glyconutrients (GLY) dosed at 5 g/calve/day in the liquid diet consisting of 4 L/d of unsaleable raw whole milk during all the study. Treatments were: 1) RAW, 2) PST, 3) RAW + GLY, and 4) PST + GLY. All calves had >5.5 g/dL of total serum protein read at 12 hours of birth. Calves were assigned to individual cages. All animals had ad libitum access to water and chopped high-quality alfalfa hay, from the fourth day, calf-starter was offered ad libitum. There was no mortality nor infectious diarrhea during the experiment. Pasteurization did not affect the quality (density, pH, and IgG concentration) of colostrum. The overall noninfectious diarrhea frequency was 53.7%. A lower diarrhea frequency was noted to calves that were fed with PST when compared to RAW treatments (45 vs. 62.5%) without differences in the number of times (1.05 vs. 1.26) needed to receive treatment to stop diarrhea. Supplemental GLY did not influence the reduction of diarrhea frequency and did not improve performance. Colostrum pasteurization increased (p <0.05) starter intake by 28.5%, the average daily gain by 35.8%, and live weight change of 9.6%. We concluded that offering pasteurized colostrum during the first hours of life is a positive strategy to increase starter intake and growth during the first 30 days of birth in rearing calves. On the other hand, using the mixture of symbiotic/glyconutrients as feed additive did not show any advantage when offered in this type of farm. تفاصيل المقالة

Twenty-four Pelibuey × Katahdin (46.7±2.4 kg initial shrunk weight) crossbred intact male lambs were used in a 33-d growth-performance experiment order to compared two sources of generic zilpaterol vs. patent zilpaterol on five variables of meat quality (water holding capacity, color, purge loss, cook loss, and shear force) shear force) of lambs finished with a high-energy diet. Dietary treatments consisted of a corn-based finishing diet (13.3% crude protein and 2.11 Mcal of net energy for maintenance/kg dry matter) supplemented with no zilpaterol (control) or supplemented with the label dosage (125 mg of product/kg diet, as-fed basis) with patent brand zilpaterol [Zilmax® (ZIL)] or with two generic ZH sources [Grofactor® (GRO) or Zipamix® (ZIPA)]. Weight at slaughter was 50.93, 54.55, 54.20, and 54.50 kg for control, ZIL, GRO, and ZIPA, respectively. The average intake of zilpaterol was 0.16 mg ZH/kg live weight. There were no differences between zilpaterol sources on meat quality variables evaluated. Compared to controls, zilpaterol supplementation did not appreciably affect color, water-holding capacity, and drip loss. However, supplemental zilpaterol averaged an increased 36% shear force (4.11 vs. 2.63). It is concluded that the generic zilpaterol sources tested in the present experiment affect similarly the meat quality of hairy lambs fed a high-energy diet than patent brand zilpaterol. Zilpaterol affected mainly the tenderness of the meat. تفاصيل المقالة

The objective was to evaluate the long-term effects of vaccination against endotoxemia on calf-fed Holstein steer growth performance, dietary energetics, and carcass characteristics. Fifty Holstein steer calves were used in a 322 d trial. Calves (134±5 kg) were randomly assigned to treatments within weight groups to 10 pens (5 steers per pen). Five pen groups received an endotoxemia vaccination on d 28 and 56 of the study (EV), and the remaining 5 pens did not receive vaccination. Calves were weighed (off-truck weight, no shrink applied) at start of the study, and on days 122 and 322 (shrunk 4% to account for gut fill). All steers were fed with a steam-flaked corn-based diet. Vaccination did not affect (P≥0.10) live weight, average daily gain, and dry matter intake during the experiment. Although vaccination increased (P=0.04) gain efficiency during the initial 112 d, differences in gain efficiency from d 112 to 322, and during the cumulative feeding period (1 to 322 d) was not appreciable (P≥0.14). Vaccination did not affect (P≥0.31) hot carcass weight, dressing percentage, or marbling score. However, vaccination increased (P<0.01) longissimus muscle area (86.5 vs. 76.8 cm2) and retail yield (51.3 vs. 50.4); but, also tended to increase (P=0.07) carcass fat thick-ness. Morbidity and pink eye rate infection were low and not affected by treatment (P≥0.18). We conclude that whereas vaccinating Holstein calves with EV at days 28 and 56 from arrival did not have an overall effect on growth-performance, it increased (13%) longissimus area and retail carcass yield (1.8%). تفاصيل المقالة