Poultry Science Department and Alabama Agricultural Research Station, Auburn University, Alabama 36849-5416; and Nutri-Quest, Inc, Chesterfield, Missouri 63017

ABSTRACT
Females approximate 30% of the broilers marketed for further processing. The need for threonine for females is known to be less than for males during the first few weeks of production; however, information is limited on any difference thereafter. This study examined responses of male and female feather-sexable broilers to diets formulated to contain three concentrations of threonine (0.52, 0.63, and 0.74% total) from 42 to 56 d of age. Male broilers optimized growth rate and feed to gain ratio when threonine approximated 0.74% of the diet; 0.63% dietary threonine was more appropriate for females. Dietary threonine concentration did not influence chilled carcass yield, abdominal fat percentage, or the proportion of "A" Grades. In agreement with live performance, males optimized fillet weight with 0.74% dietary threonine; 0.63% was adequate for females. The need for dietary threonine to optimize live performance and recovery of the breast fillets is less for females than for males during 42 to 56 d of age.

Key words: Amino acid, breast meat, broiler, threonine

J. Appl. Poultry Res., 2001. 10:53-59

Department of Poultry Science, Mississippi State University, MS, USA

Aims: The purpose of these experiments was to determine whether the heart and lungs of young chicks harboured bacteria.
Methods and Results: Samples of the heart and lungs were aseptically removed from chicks on scheduled sampling days. Experiment 1 showed that of the 360 birds evaluated during the late embryonic and early post-hatching periods, only 10.8% harboured bacteria in the heart, lungs, and heart and lungs simultaneously. Experiment 2 suggested that bacteria in these organs were transient. Twenty-three bacterial species were found in the hearts whereas 30 were found in the lungs. Experiment 3 showed that only 1.4% of embryos harboured bacteria in the yolk, albumen, heart and lungs whereas 12.9% of the embryos had bacteria in the air cell.
Conclusions: During the post-hatching period, there was a higher incidence of bacterial isolation in the heart and lungs, whilst during the embryonic development period, there was a lower incidence of bacterial isolation from these two organs. Results suggested that the heart and lungs do not have a residual bacterial flora; rather, opportunistic bacteria occasionally pass through these tissues.
Significance and Impact of the Study: These experiments proved that bacteria could be isolated in the heart and lungs of healthy chicks reared from E17 to 3 weeks of age.

Journal of Applied Microbiology, 2002. 92:443-450

P. D. Gerard
Experimental Statistics Unit, Mississippi State University, MS

M. A. Latour
Department of Animal Sciences, Purdue University, IN

Summary: Beginning at 22 wk of age, broiler breeder hens were fed one of six experimental diets. Diets 1 and 2 were fed to provide each bird an ME intake of 467 kcal/day (high) at peak production [467 peak Calories/day (PCD)], whereas Diets 3 and 4 contained low ME levels (430 PCD),and Diets 5 and 6 contained moderate ME levels (449 PCD). Diets 1 and 3 contained 3.0% added poultry fat, Diets 2 and 4 contained no added fat, Diet 5 contained 1.5% added poultry fat, and Diet 6 contained 3.0% added corn oil. Eggs were collected when hens were 29 wk of age. Embryonic mortality, hatchability, and subsequent growout performance were assessed through 42 d of broiler age. Added fat type (poultry fat or corn oil), poultry fat level (1.5 or 3.0%), or ME level from low (430 PCD) to high (467 PCD) in the diets of young (29-wk-old) breeder hens had no effects on subsequent embryogenesis, hatchability, or posthatch growout performance of broiler offspring. It was concluded that 1.5 and 3.0% added poultry fat or 3.0% corn oil may be effectively used to adjust ME between low and high levels in the diets of young breeder hens without subsequent effects on broiler embryogenesis and growout performance.

Key words: broiler breeder, broiler chick, dietary fat, feed conversion, growth

J. Appl. Poultry Res., 2002. 11:146-154

ABSTRACT
If semen quality was known prior to insemination, sperm doses could possibly be decreased, maximizing the number of hens inseminated. The sperm quality index (SQI), an indicator of overall semen quality, is determined by the number of deflections in a light path due to sperm movement inside a capillary tube. The objectives of this study were 1) to determine the age at which the SQI becomes a static predictor of semen quality and 2) to determine if fertility of males with a higher SQI responds more favorably to insemination dose reduction than that of males with a lower SQI. Weekly from 23 to 32 wk of age, 144 Cobb males were tested for SQI. At 32 wk of age, males were placed into four groups that represented the SQI population quartiles as follows: poor, fair, good, and best. A fifth SQI group, uncategorized, was created to determine fertility of the original population by mixing equal amounts of semen from each of the four groups. Semen was collected weekly from 33 to 40 wk of age from 18 males in each of the four groups, pooled by group, and used to inseminate 30 hens per group with 50 or 100 million sperm. Eggs were collected daily, incubated, and broken out to determine fertility. Correlation coefficients between weekly SQI results and overall averages for individual males indicated that the SQI stabilized after the birds were 28 wk of age. The main effect for SQI selection revealed that the best SQI group had the highest fertility (88%), which did not differ from the good (83%) or fair group (82%) but was greater than the uncategorized group (80%). Fertilities of the top three groups and the uncategorized group were higher than the poor group (63%) (P < 0.0001, SEM 2.18). In addition, there was an interaction between SQI classification and insemination dose. Fertilities of the top three SQI groups were similar at the 50 and 100 million sperm doses. However, the poor and uncategorized SQI groups had lower fertility at the 50 million dose as compared to the 100 million dose. By categorizing males into SQI groups after 28 wk of age, insemination dose can be reduced, maximizing a male's fertilizing potential.

Key words: sperm quality index, broiler breeder, fertility, insemination dose

Poultry Science, 2002. 81:239-245

ABSTRACT
1. A relatively new instrument known as a Sperm Quality Analyzer® (SQA) offers a rapid assessment of sperm quality and quantity by providing a sperm quality index (SQI) . The SQA measures the intensity of sperm activity and motile concentration by determining the number and amplitude of sperm movements per second in a capillary tube as detected through light beam interference.
2. The objectives of the current study were to determine if the SQA could accurately reflect changes in semen quality that occur with prolonged storage of semen and to determine the variation and change in SQI values among individual breeding male turkeys during their semen production cycle.
3. The effect of storage time on SQI values was evaluated by diluting semen with extender and placing the semen on an oscillating shaker at 4şC for 8 h. The SQI values and sperm viability, expressed as % dead sperm, were recorded hourly. The SQI readings declined linearly with increased storage time, while % dead sperm increased linearly with increased semen storage.
4. Semen from 220 individual males was analysed monthly for 9 months. Semen diluted 50-fold with saline had lower SQI values during pre- and post-peak phases of production (months 1, 7, 8, and 9 as compared with months 2 to 6 of semen production). The highest SQI values occurred during months 2 to 6. The largest variation in SQI values occurred during months 1 (CV = 26%) and 9 (CV = 31%) with a CV that averaged 16% for the remaining months.
5. Correlation analysis of SQI values for each bird averaged over 9 months with individual male SQIs for each month showed monthly correlation coefficients that ranged from 0.22 to 0.63.
6. These results indicate that the SQA accurately assessed the decline in sperm quality that occurs with prolonged storage of turkey semen and reflected age-related changes in semen quality and quantity that occurred during a semen production cycle of turkey breeders. In addition, the semen quality rank of some turkey breeders in a population changed with age.

British Poultry Science, 2002. 43:465-471

Key Words: layer, liver, Mycoplasma gallisepticum, reproductive tract, small intestine

2002 Poultry Science 81:1884-1891

¹Poultry Science Department, University of Arkansas ²Nutri-Quest, Inc., Chesterfield, MO

Abstract:
An experiment was conduced to estimate the Thr needs of male Large White turkeys from 8 to 12 week of age and to evaluate the effects of dietary CP on Thr needs. The dietary treatments consisted of a 2 x 6 factorial arrangement with two levels of CP (16.0 and 19.8%), each containing 0.50% total Thr by analysis. Aliquots of each CP basal diet were supplemented with L-Thr to provide total Thr levels of 0.50, 0.57, 0.64, 0.71, 0.78, and 0.85%. Initial and final bird weights were taken to determine BW gain; feed conversion ratios were calculated with adjustment for weight of birds that died during the study. Nonlinear and quadratic regression analyses were used to estimate a Thr requirement to optimize BW gain and feed conversion. For both BW gain and feed conversion, significant interactions were observed between dietary CP and Thr levels. Performance was superior for poults fed the low CP diet series, noted primarily at the lower levels of Thr. As levels of Thr reached a surfet, no significant differences in performance were noted between poults fed the two CP levels. Using nonlinear regression analysis, dietary Thr levels of 0.68 (16.0% CP) and 0.76% (19.8%) were adequate for maximum BW gain while Thr levels of 0.61 (16.0% CP) and 0.70% (19.8%) were adequate for optimum feed conversion. However, when estimates were based on fitting a quadratic regression, dietary Thr levels of 0.83 (16.0% CP) and 0.98% (19.8%) were adequate for maximum BW gain, while Thr levels of 0.77 (16.0% CP) and 0.82% (19.8%) were adequate for optimum feed conversion. While the interactions between dietary CP and Thr may be interpreted to suggest that dietary CP levels influence amino acid requirements, the two basal diets were composed of protein sources that differ in digestibility of Thr. It is possible that the reduced BW gains and impaired feed conversion observed at the lowest level of Thr supplementation on the high CP diets were the result of a lower level of digestible Thr, rather than a direct influence of CP level per se.

Key Words: Turkeys, threonine, crude protein, requirements

International Journal of Poultry Science 1 (4): 74-77, 2002

¹College of Veterinary Medicine, and ²Poultry Science Department, Mississippi State University, Mississippi State, Mississippi 39762

Summary
Two trials were conducted to determine if gluconeogenic supplementation (GS) via injection at day of hatch would facilitate early survivability and growth in chicks form immature breeder hens under adequate brooding conditions. Early chick mortality and feed conversion were not influenced by treatment; however, BW between Days 1 and 6 postinjection were influenced by treatment. An unexpected positive response to injected saline was observed, but GS provided a greater effect on BW at two times. These results suggest that under proper brooding conditions, chick growth may be facilitated by saline or supplemental gluconeogenic nutrients during early transition from fat to carbohydrate-based nutrient uptake in posthatch chicks. However, normal growth was achieved in chicks from a young flock when provided adequate brooding conditions.

Key words: breeder, brooding, chick, gluconeogenesis, growth, mortality, pullet

J. Appl. Poult. Res. 11:367-372, 2002

Department of Poultry Science, Mississippi State University, Mississippi State, Mississippi 39762

Summary
Enterococcus faecalis when administered in a growth medium or sterile saline, will cause pulmonary hypertension syndrome (PHS) in chickens. The objective of this study was to determine if frozen and/or autoclaves cultures of E. faecalis retain ability to evoke PHS. In Trial 1, chicks were inoculated with 3.6 x 107 E. faecalis (IA) in tryptic soy broth (TSB) from either a live culture or one that had been autoclaves (120^o C for 20 min). Controls received TSB. Autoclaves and live cultures produced the same degree of PHS in a majority of the birds. Trial 2 used the same protocol, except a frozen (-70^o C for 60 min) culture of E. faecalis was compared with the control. The results agreed with those of Trial 1, i.e., the frozen culture also produced PHS. Trial 3 was conducted to determine if E. faecalis caused PHS by producing and releasing some unknown substance into the supernatant. Incidence of PHS was based on percentage of birds exhibiting ascites fluid at 24 hr after challenge. Controls received sterile, frozen, or autoclaved TSB. As compared with controls, those birds that received challenge with E. faecalis alone, supernatant alone, and E. faecalis plus supernatant from live cultures exhibited similar incidence of ascites, whereas birds that received E. faecalis plus supernatant and supernatant alone from cultures that had been either frozen or autoclaved exhibited elevated incidence of ascites as compared with controls. Also, with frozen and autoclaved cultures, those birds that received only pelleted E. faecalis exhibited incidence of aspires that did not differ from controls. Apparently, E. faecalis produces PHS in chicks by producing and releasing an unknown toxin.

Key words: E. faecalis; chicken; pulmonary; hypertension; supernatant.

Exp Biol Med 227:812-816, 2002

¹Department of Poultry Science and ³Experimental Statistics Unit, Mississippi State University, Mississippi State, Mississippi 39762; ²South Central Poultry Research Laboratory, Mississippi State, Mississippi 39762

ABSTRACT
F-strain Mycoplasma gallisepticum (FMG) may alter reproductive performance in layers through its effects on lipid metabolism. Therefore, the influences of 1.5% supplemental dietary poultry fat (PF) and FMG infection on the early performance of commercial egg-laying hens were determined. Birds were either sham- or FMG-inoculated at 12 wk, and experimental diets were initiated at 20 wk of age. Body weight at 12, 20, and 24 wk, total daily egg mass, feed consumption and feed conversion at 20 and 24 wk, weekly egg weight between 19 and 26 wk, weekly egg production (EP) between 18 and 26 wk, and weekly mortality between 12 and 26 wk of age were determined. Inoculation with FMG reduced EP at 18 and 19 wk of age. Between 20 and 26 wk, FMG reduced EP in birds fed control diets, conversely, PF eliminated differences in EP between sham- and FMG-inoculated birds. Furthermore, at wk 20 and 24, birds consumed less feed when fed PF-supplemented diets than when fed control diets if they were sham-inoculated, but the difference in feed consumption between diets was ameliorated if birds were previously inoculated with FMG. These data demonstrate that the effects of a 12-wk inoculation of FMG on EP and feed consumption through 26 wk of age in commercial egg-laying chickens can be modified by 1.5% supplemental dietary PF. More specifically, PF may alleviate reductions in early EP due to FMG.

Key Words: commercial layer, egg production, F-strain Mycoplasma gallisepticum, performance, poultry fat)

Poultry Science 82:596-602,2003