Yield, composition, and in vitro digestibility of temperate and tropical corn hybrids grown as silage crops planted in summer.

Following the harvest of corn silage crops that were planted in spring, second crops of one temperate and four tropical corn hybrids were planted under conditions of minimum tilling in four replications on August 3, 1992 and harvested on October 11, 1992 (yr 1). During the 2nd yr, second crops were planted on July 21, 1993 and harvested on October 19, 1993. Dry matter yields of the hybrids ranked similarly for both years but differed among hybrids, ranging from 7800 to 11,430 kg/ha (yr 1) and from 8470 to 13,150 kg/ha (yr 2).

Digestibility and utilization of pearl millet diets fed to finishing beef cattle.

Pearl millet grain was blended with corn in 1:1 or 2:1 ratios in beef finishing diets fed in two metabolism and two feedlot trials. In Exp. 1, diets contained 1) 79.

Substitution of peanut skins for soybean hulls in steer finishing diets containing recommended and elevated crude protein levels.

A steer finishing trial was conducted to study the substitution of peanut skins (PS) for soybean hulls (SH) when included at three levels (0, 7.5, or 15%) in diets containing recommended (10.5% = RP) or elevated (15.

Breeding performance of beef bulls assigned to two-sire cow groups on pasture.

Angus, Polled Hereford and Santa Gertrudis bulls from ages 1 through 5 and 7 yr were assigned to 26 two-sire breeding groups. Each year, straightbred and crossbred cows of these breeds were allotted at random within breed composition, age of dam and calving date to breeding groups on pasture. Sires within each breeding group or pair were the same age at breeding and were two of the three breeds of sires.

Feedlot performance and pregnancy inhibition of heifers treated with depot-formulated melengestrol acetate.

In dose titration trials beef heifers received depot-formulated melengestrol acetate (DEPO-MGA) in single s.c. ear injections to determine effects on performance and pregnancy inhibition.

Relationship of breeding soundness evaluation score and its components with reproductive performance of beef bulls.

Angus, Polled Hereford and Santa Gertrudis bulls were subjected to a breeding soundness evaluation (BSE) just prior to being exposed to cows for 90 to 95 days in single-sire units under natural breeding conditions on pasture. Forty-eight of 55 bulls subjected to scrotal and semen evaluations passed the BSE and were considered acceptable for breeding. Of the bulls that passed BSE, 18 (six bulls from each breed) were used for breeding for each yr of the 2-yr study.

Reproduction and calf performance of Angus-sired and Polled Hereford-sired cows bred to Angus and Brahman bulls for primiparous calving as two- vs three-year-olds.

This 4-yr study was conducted with Angus (A)-sired and Polled Hereford (PH)-sired crossbred heifers that were exposed to either A or medium-frame Brahman (B) bulls from primiparous calvings either as 2- or 3-yr-olds. Each year, heifers were allotted at random within breed composition and age of dam to breeding groups on pasture for an 84-d breeding period that began in late March or early April. Results indicated that differences due to age of dam (AOD), calf sire breed (CSB) and dam sire breed (DSB) were similar for calving rate, earliness of calving in the calving period and percentage of calves born alive, percentage weaned of those born alive and percentage weaned of cows exposed.

Breeding performance of bulls assigned either to 40 cows per bull or 80 cows per two bulls during the breeding period.

The reproductive performance of Angus (A), Polled Hereford (PH) and Santa Gertrudis (SG) bulls was compared when exposed to 40 cows/bull vs 80 cows/two bulls during a 90- to 95-d breeding period on pasture. Cows were A, PH and SG straightbreds and crossbreds of these breeds. Each year, cows were allotted at random within breed composition and age of dam to breeding groups.

Cow breeding and calf growth performance as affected by pregnancy status the previous year.

A 2-yr study was conducted to compare the subsequent cow breeding and calf performance of cows that were nonpregnant with cows that were pregnant at the time calves were weaned. Cows were Angus (A), Polled Hereford (PH), Santa Gertrudis (SG) straightbreds and crossbreds of these breeds. Nonpregnant cows (G1) were 4- to 9-yr-olds that had a calf the previous year and appeared to be physically sound with no detection (by rectal palpation) of an abnormal reproductive tract due to disease, abnormal growth or calving difficulties.

Dietary urea influences on digestibility and utilization of diets containing peanut skins by steers.

Metabolism and feedlot trials were conducted to evaluate increased dietary urea as a method of reducing detrimental effects of peanut skin (PS) tannins on nutrient digestibility and finishing steer performance. The PS fed in the trials contained 17.8% crude protein and 20.

Digestibility and utilization of ammonia-treated and urea-supplemented peanut skin diets fed to cattle.

A metabolism study and two feedlot trials were conducted to evaluate urea supplementation of peanut skin (PS) diets and ammoniation of PS as methods of reducing detrimental effects of tannins in PS on nutrient digestibility and performance of beef cattle. Tannin content of PS was reduced by 42% after ammoniation. Digestibility coefficients for dry matter, crude protein, nitrogen free extract, energy and total digestible nutrients were higher (P less than .

Influence of dietary crude protein on peanut skin digestibility and utilization by feedlot steers.

Peanut skins were fed at 15% of steer diets in metabolism and feedlot trials. Elevation of dietary protein using soybean meal or soybean meal plus urea and ammoniation of skins were evaluated as methods of overcoming detrimental performance and digestibility effects of tannins in peanut skins. Digestibility of dry matter, crude protein and energy were not different (P greater than .

Castration method and progesterone-estradiol implant effects on growth rate of suckling calves.

Eighty male calves nursing their dams and averaging 15 d of age were used to evaluate a method of nonsurgical castration and a growth implant in a 196-d experiment. On the 1st d of the experiment, 40 calves were castrated chemically using Chem-Cast (active ingredient: lactic acid 88% wt/wt), and 40 were castrated surgically. Twenty calves on each castration treatment were implanted with STEER-oid on d 1 and reimplanted on d 121 while 20 calves on each treatment were not implanted on either date.

Effects of feeding wheat contaminated with wild radish (Raphanus raphanistrum) to growing pigs.

In each of two growth trials, weanling pigs were individually housed and fed to study the effect of various amounts of wild radish (Raphanus raphanistrum) seed pods in the diet on performance of growing swine. For trial 1, 20 pigs averaging 19.6 kg live weight were divided into four comparable groups of five pigs each based on sex and initial weight and were assigned to fortified wheat-soybean meal diets with: (1) 0%, (2) 1.

Comparative performance of straightbred and crossbred (F1) sires.

The first phase of this study was the production of contemporary straightbred (SB) and reciprocal crossbred (F1) bulls by mating Angus (A) bulls to A and Santa Gertrudis (SG) cows and SG bulls to SG and A cows. Of the bulls produced during the 4-yr period, those used for breeding included 15 A, 15 SG, 8 A X SG and 8 SG X A. For 205-d weight and weight/day of age (W/DA) postweaning, A X SG had higher (P less than .

Anthelmintic treatment of subclinical parasitism of feedlot cattle in Georgia.

Forty heifer calves, 27 yearling heifers, and 64 yearling steers with naturally occurring infections of nematode parasites were treated with levamisole HCl or morantel tartrate or were not treated. Although heifer calves had much larger worm egg counts before treatment than yearling heifers, necropsies showed a smaller average number of nematodes in the calves. Both anthelmintics significantly reduced the egg counts.